3024 строки
75 KiB
C
3024 строки
75 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Driver for AMBA serial ports
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*
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* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
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*
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* Copyright 1999 ARM Limited
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* Copyright (C) 2000 Deep Blue Solutions Ltd.
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* Copyright (C) 2010 ST-Ericsson SA
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*
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* This is a generic driver for ARM AMBA-type serial ports. They
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* have a lot of 16550-like features, but are not register compatible.
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* Note that although they do have CTS, DCD and DSR inputs, they do
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* not have an RI input, nor do they have DTR or RTS outputs. If
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* required, these have to be supplied via some other means (eg, GPIO)
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* and hooked into this driver.
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*/
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#include <linux/module.h>
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#include <linux/ioport.h>
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#include <linux/init.h>
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#include <linux/console.h>
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#include <linux/sysrq.h>
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#include <linux/device.h>
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#include <linux/tty.h>
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#include <linux/tty_flip.h>
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#include <linux/serial_core.h>
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#include <linux/serial.h>
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#include <linux/amba/bus.h>
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#include <linux/amba/serial.h>
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#include <linux/clk.h>
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#include <linux/slab.h>
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#include <linux/dmaengine.h>
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#include <linux/dma-mapping.h>
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#include <linux/scatterlist.h>
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#include <linux/delay.h>
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#include <linux/types.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/sizes.h>
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#include <linux/io.h>
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#include <linux/acpi.h>
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#include "amba-pl011.h"
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#define UART_NR 14
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#define SERIAL_AMBA_MAJOR 204
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#define SERIAL_AMBA_MINOR 64
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#define SERIAL_AMBA_NR UART_NR
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#define AMBA_ISR_PASS_LIMIT 256
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#define UART_DR_ERROR (UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE)
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#define UART_DUMMY_DR_RX (1 << 16)
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static u16 pl011_std_offsets[REG_ARRAY_SIZE] = {
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[REG_DR] = UART01x_DR,
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[REG_FR] = UART01x_FR,
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[REG_LCRH_RX] = UART011_LCRH,
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[REG_LCRH_TX] = UART011_LCRH,
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[REG_IBRD] = UART011_IBRD,
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[REG_FBRD] = UART011_FBRD,
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[REG_CR] = UART011_CR,
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[REG_IFLS] = UART011_IFLS,
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[REG_IMSC] = UART011_IMSC,
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[REG_RIS] = UART011_RIS,
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[REG_MIS] = UART011_MIS,
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[REG_ICR] = UART011_ICR,
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[REG_DMACR] = UART011_DMACR,
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};
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/* There is by now at least one vendor with differing details, so handle it */
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struct vendor_data {
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const u16 *reg_offset;
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unsigned int ifls;
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unsigned int fr_busy;
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unsigned int fr_dsr;
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unsigned int fr_cts;
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unsigned int fr_ri;
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unsigned int inv_fr;
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bool access_32b;
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bool oversampling;
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bool dma_threshold;
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bool cts_event_workaround;
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bool always_enabled;
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bool fixed_options;
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unsigned int (*get_fifosize)(struct amba_device *dev);
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};
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static unsigned int get_fifosize_arm(struct amba_device *dev)
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{
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return amba_rev(dev) < 3 ? 16 : 32;
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}
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static struct vendor_data vendor_arm = {
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.reg_offset = pl011_std_offsets,
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.ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
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.fr_busy = UART01x_FR_BUSY,
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.fr_dsr = UART01x_FR_DSR,
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.fr_cts = UART01x_FR_CTS,
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.fr_ri = UART011_FR_RI,
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.oversampling = false,
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.dma_threshold = false,
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.cts_event_workaround = false,
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.always_enabled = false,
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.fixed_options = false,
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.get_fifosize = get_fifosize_arm,
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};
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static const struct vendor_data vendor_sbsa = {
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.reg_offset = pl011_std_offsets,
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.fr_busy = UART01x_FR_BUSY,
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.fr_dsr = UART01x_FR_DSR,
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.fr_cts = UART01x_FR_CTS,
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.fr_ri = UART011_FR_RI,
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.access_32b = true,
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.oversampling = false,
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.dma_threshold = false,
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.cts_event_workaround = false,
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.always_enabled = true,
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.fixed_options = true,
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};
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#ifdef CONFIG_ACPI_SPCR_TABLE
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static const struct vendor_data vendor_qdt_qdf2400_e44 = {
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.reg_offset = pl011_std_offsets,
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.fr_busy = UART011_FR_TXFE,
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.fr_dsr = UART01x_FR_DSR,
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.fr_cts = UART01x_FR_CTS,
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.fr_ri = UART011_FR_RI,
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.inv_fr = UART011_FR_TXFE,
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.access_32b = true,
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.oversampling = false,
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.dma_threshold = false,
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.cts_event_workaround = false,
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.always_enabled = true,
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.fixed_options = true,
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};
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#endif
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static u16 pl011_st_offsets[REG_ARRAY_SIZE] = {
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[REG_DR] = UART01x_DR,
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[REG_ST_DMAWM] = ST_UART011_DMAWM,
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[REG_ST_TIMEOUT] = ST_UART011_TIMEOUT,
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[REG_FR] = UART01x_FR,
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[REG_LCRH_RX] = ST_UART011_LCRH_RX,
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[REG_LCRH_TX] = ST_UART011_LCRH_TX,
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[REG_IBRD] = UART011_IBRD,
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[REG_FBRD] = UART011_FBRD,
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[REG_CR] = UART011_CR,
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[REG_IFLS] = UART011_IFLS,
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[REG_IMSC] = UART011_IMSC,
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[REG_RIS] = UART011_RIS,
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[REG_MIS] = UART011_MIS,
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[REG_ICR] = UART011_ICR,
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[REG_DMACR] = UART011_DMACR,
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[REG_ST_XFCR] = ST_UART011_XFCR,
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[REG_ST_XON1] = ST_UART011_XON1,
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[REG_ST_XON2] = ST_UART011_XON2,
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[REG_ST_XOFF1] = ST_UART011_XOFF1,
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[REG_ST_XOFF2] = ST_UART011_XOFF2,
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[REG_ST_ITCR] = ST_UART011_ITCR,
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[REG_ST_ITIP] = ST_UART011_ITIP,
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[REG_ST_ABCR] = ST_UART011_ABCR,
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[REG_ST_ABIMSC] = ST_UART011_ABIMSC,
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};
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static unsigned int get_fifosize_st(struct amba_device *dev)
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{
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return 64;
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}
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static struct vendor_data vendor_st = {
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.reg_offset = pl011_st_offsets,
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.ifls = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF,
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.fr_busy = UART01x_FR_BUSY,
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.fr_dsr = UART01x_FR_DSR,
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.fr_cts = UART01x_FR_CTS,
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.fr_ri = UART011_FR_RI,
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.oversampling = true,
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.dma_threshold = true,
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.cts_event_workaround = true,
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.always_enabled = false,
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.fixed_options = false,
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.get_fifosize = get_fifosize_st,
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};
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static const u16 pl011_zte_offsets[REG_ARRAY_SIZE] = {
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[REG_DR] = ZX_UART011_DR,
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[REG_FR] = ZX_UART011_FR,
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[REG_LCRH_RX] = ZX_UART011_LCRH,
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[REG_LCRH_TX] = ZX_UART011_LCRH,
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[REG_IBRD] = ZX_UART011_IBRD,
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[REG_FBRD] = ZX_UART011_FBRD,
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[REG_CR] = ZX_UART011_CR,
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[REG_IFLS] = ZX_UART011_IFLS,
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[REG_IMSC] = ZX_UART011_IMSC,
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[REG_RIS] = ZX_UART011_RIS,
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[REG_MIS] = ZX_UART011_MIS,
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[REG_ICR] = ZX_UART011_ICR,
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[REG_DMACR] = ZX_UART011_DMACR,
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};
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static unsigned int get_fifosize_zte(struct amba_device *dev)
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{
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return 16;
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}
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static struct vendor_data vendor_zte = {
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.reg_offset = pl011_zte_offsets,
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.access_32b = true,
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.ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
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.fr_busy = ZX_UART01x_FR_BUSY,
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.fr_dsr = ZX_UART01x_FR_DSR,
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.fr_cts = ZX_UART01x_FR_CTS,
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.fr_ri = ZX_UART011_FR_RI,
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.get_fifosize = get_fifosize_zte,
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};
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/* Deals with DMA transactions */
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struct pl011_sgbuf {
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struct scatterlist sg;
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char *buf;
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};
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struct pl011_dmarx_data {
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struct dma_chan *chan;
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struct completion complete;
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bool use_buf_b;
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struct pl011_sgbuf sgbuf_a;
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struct pl011_sgbuf sgbuf_b;
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dma_cookie_t cookie;
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bool running;
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struct timer_list timer;
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unsigned int last_residue;
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unsigned long last_jiffies;
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bool auto_poll_rate;
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unsigned int poll_rate;
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unsigned int poll_timeout;
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};
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struct pl011_dmatx_data {
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struct dma_chan *chan;
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struct scatterlist sg;
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char *buf;
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bool queued;
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};
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/*
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* We wrap our port structure around the generic uart_port.
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*/
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struct uart_amba_port {
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struct uart_port port;
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const u16 *reg_offset;
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struct clk *clk;
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const struct vendor_data *vendor;
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unsigned int dmacr; /* dma control reg */
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unsigned int im; /* interrupt mask */
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unsigned int old_status;
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unsigned int fifosize; /* vendor-specific */
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unsigned int old_cr; /* state during shutdown */
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unsigned int fixed_baud; /* vendor-set fixed baud rate */
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char type[12];
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bool rs485_tx_started;
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unsigned int rs485_tx_drain_interval; /* usecs */
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#ifdef CONFIG_DMA_ENGINE
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/* DMA stuff */
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bool using_tx_dma;
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bool using_rx_dma;
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struct pl011_dmarx_data dmarx;
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struct pl011_dmatx_data dmatx;
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bool dma_probed;
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#endif
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};
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static unsigned int pl011_tx_empty(struct uart_port *port);
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static unsigned int pl011_reg_to_offset(const struct uart_amba_port *uap,
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unsigned int reg)
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{
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return uap->reg_offset[reg];
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}
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static unsigned int pl011_read(const struct uart_amba_port *uap,
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unsigned int reg)
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{
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void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
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return (uap->port.iotype == UPIO_MEM32) ?
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readl_relaxed(addr) : readw_relaxed(addr);
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}
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static void pl011_write(unsigned int val, const struct uart_amba_port *uap,
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unsigned int reg)
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{
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void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
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if (uap->port.iotype == UPIO_MEM32)
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writel_relaxed(val, addr);
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else
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writew_relaxed(val, addr);
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}
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/*
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* Reads up to 256 characters from the FIFO or until it's empty and
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* inserts them into the TTY layer. Returns the number of characters
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* read from the FIFO.
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*/
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static int pl011_fifo_to_tty(struct uart_amba_port *uap)
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{
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unsigned int ch, flag, fifotaken;
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int sysrq;
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u16 status;
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for (fifotaken = 0; fifotaken != 256; fifotaken++) {
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status = pl011_read(uap, REG_FR);
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if (status & UART01x_FR_RXFE)
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break;
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/* Take chars from the FIFO and update status */
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ch = pl011_read(uap, REG_DR) | UART_DUMMY_DR_RX;
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flag = TTY_NORMAL;
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uap->port.icount.rx++;
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if (unlikely(ch & UART_DR_ERROR)) {
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if (ch & UART011_DR_BE) {
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ch &= ~(UART011_DR_FE | UART011_DR_PE);
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uap->port.icount.brk++;
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if (uart_handle_break(&uap->port))
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continue;
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} else if (ch & UART011_DR_PE)
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uap->port.icount.parity++;
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else if (ch & UART011_DR_FE)
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uap->port.icount.frame++;
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if (ch & UART011_DR_OE)
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uap->port.icount.overrun++;
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ch &= uap->port.read_status_mask;
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if (ch & UART011_DR_BE)
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flag = TTY_BREAK;
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else if (ch & UART011_DR_PE)
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flag = TTY_PARITY;
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else if (ch & UART011_DR_FE)
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flag = TTY_FRAME;
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}
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spin_unlock(&uap->port.lock);
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sysrq = uart_handle_sysrq_char(&uap->port, ch & 255);
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spin_lock(&uap->port.lock);
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if (!sysrq)
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uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag);
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}
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return fifotaken;
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}
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/*
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* All the DMA operation mode stuff goes inside this ifdef.
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* This assumes that you have a generic DMA device interface,
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* no custom DMA interfaces are supported.
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*/
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#ifdef CONFIG_DMA_ENGINE
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#define PL011_DMA_BUFFER_SIZE PAGE_SIZE
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static int pl011_sgbuf_init(struct dma_chan *chan, struct pl011_sgbuf *sg,
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enum dma_data_direction dir)
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{
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dma_addr_t dma_addr;
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sg->buf = dma_alloc_coherent(chan->device->dev,
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PL011_DMA_BUFFER_SIZE, &dma_addr, GFP_KERNEL);
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if (!sg->buf)
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return -ENOMEM;
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sg_init_table(&sg->sg, 1);
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sg_set_page(&sg->sg, phys_to_page(dma_addr),
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PL011_DMA_BUFFER_SIZE, offset_in_page(dma_addr));
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sg_dma_address(&sg->sg) = dma_addr;
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sg_dma_len(&sg->sg) = PL011_DMA_BUFFER_SIZE;
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return 0;
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}
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static void pl011_sgbuf_free(struct dma_chan *chan, struct pl011_sgbuf *sg,
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enum dma_data_direction dir)
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{
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if (sg->buf) {
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dma_free_coherent(chan->device->dev,
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PL011_DMA_BUFFER_SIZE, sg->buf,
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sg_dma_address(&sg->sg));
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}
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}
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static void pl011_dma_probe(struct uart_amba_port *uap)
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{
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/* DMA is the sole user of the platform data right now */
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struct amba_pl011_data *plat = dev_get_platdata(uap->port.dev);
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struct device *dev = uap->port.dev;
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struct dma_slave_config tx_conf = {
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.dst_addr = uap->port.mapbase +
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pl011_reg_to_offset(uap, REG_DR),
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.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
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.direction = DMA_MEM_TO_DEV,
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.dst_maxburst = uap->fifosize >> 1,
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.device_fc = false,
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};
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struct dma_chan *chan;
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dma_cap_mask_t mask;
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uap->dma_probed = true;
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chan = dma_request_chan(dev, "tx");
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if (IS_ERR(chan)) {
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if (PTR_ERR(chan) == -EPROBE_DEFER) {
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uap->dma_probed = false;
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return;
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}
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/* We need platform data */
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if (!plat || !plat->dma_filter) {
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dev_info(uap->port.dev, "no DMA platform data\n");
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return;
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}
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/* Try to acquire a generic DMA engine slave TX channel */
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dma_cap_zero(mask);
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dma_cap_set(DMA_SLAVE, mask);
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chan = dma_request_channel(mask, plat->dma_filter,
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plat->dma_tx_param);
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if (!chan) {
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dev_err(uap->port.dev, "no TX DMA channel!\n");
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return;
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}
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}
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dmaengine_slave_config(chan, &tx_conf);
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uap->dmatx.chan = chan;
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dev_info(uap->port.dev, "DMA channel TX %s\n",
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dma_chan_name(uap->dmatx.chan));
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/* Optionally make use of an RX channel as well */
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chan = dma_request_slave_channel(dev, "rx");
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if (!chan && plat && plat->dma_rx_param) {
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chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param);
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if (!chan) {
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dev_err(uap->port.dev, "no RX DMA channel!\n");
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return;
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}
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}
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if (chan) {
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struct dma_slave_config rx_conf = {
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.src_addr = uap->port.mapbase +
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pl011_reg_to_offset(uap, REG_DR),
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.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
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.direction = DMA_DEV_TO_MEM,
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.src_maxburst = uap->fifosize >> 2,
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.device_fc = false,
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};
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struct dma_slave_caps caps;
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/*
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* Some DMA controllers provide information on their capabilities.
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* If the controller does, check for suitable residue processing
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* otherwise assime all is well.
|
|
*/
|
|
if (0 == dma_get_slave_caps(chan, &caps)) {
|
|
if (caps.residue_granularity ==
|
|
DMA_RESIDUE_GRANULARITY_DESCRIPTOR) {
|
|
dma_release_channel(chan);
|
|
dev_info(uap->port.dev,
|
|
"RX DMA disabled - no residue processing\n");
|
|
return;
|
|
}
|
|
}
|
|
dmaengine_slave_config(chan, &rx_conf);
|
|
uap->dmarx.chan = chan;
|
|
|
|
uap->dmarx.auto_poll_rate = false;
|
|
if (plat && plat->dma_rx_poll_enable) {
|
|
/* Set poll rate if specified. */
|
|
if (plat->dma_rx_poll_rate) {
|
|
uap->dmarx.auto_poll_rate = false;
|
|
uap->dmarx.poll_rate = plat->dma_rx_poll_rate;
|
|
} else {
|
|
/*
|
|
* 100 ms defaults to poll rate if not
|
|
* specified. This will be adjusted with
|
|
* the baud rate at set_termios.
|
|
*/
|
|
uap->dmarx.auto_poll_rate = true;
|
|
uap->dmarx.poll_rate = 100;
|
|
}
|
|
/* 3 secs defaults poll_timeout if not specified. */
|
|
if (plat->dma_rx_poll_timeout)
|
|
uap->dmarx.poll_timeout =
|
|
plat->dma_rx_poll_timeout;
|
|
else
|
|
uap->dmarx.poll_timeout = 3000;
|
|
} else if (!plat && dev->of_node) {
|
|
uap->dmarx.auto_poll_rate = of_property_read_bool(
|
|
dev->of_node, "auto-poll");
|
|
if (uap->dmarx.auto_poll_rate) {
|
|
u32 x;
|
|
|
|
if (0 == of_property_read_u32(dev->of_node,
|
|
"poll-rate-ms", &x))
|
|
uap->dmarx.poll_rate = x;
|
|
else
|
|
uap->dmarx.poll_rate = 100;
|
|
if (0 == of_property_read_u32(dev->of_node,
|
|
"poll-timeout-ms", &x))
|
|
uap->dmarx.poll_timeout = x;
|
|
else
|
|
uap->dmarx.poll_timeout = 3000;
|
|
}
|
|
}
|
|
dev_info(uap->port.dev, "DMA channel RX %s\n",
|
|
dma_chan_name(uap->dmarx.chan));
|
|
}
|
|
}
|
|
|
|
static void pl011_dma_remove(struct uart_amba_port *uap)
|
|
{
|
|
if (uap->dmatx.chan)
|
|
dma_release_channel(uap->dmatx.chan);
|
|
if (uap->dmarx.chan)
|
|
dma_release_channel(uap->dmarx.chan);
|
|
}
|
|
|
|
/* Forward declare these for the refill routine */
|
|
static int pl011_dma_tx_refill(struct uart_amba_port *uap);
|
|
static void pl011_start_tx_pio(struct uart_amba_port *uap);
|
|
|
|
/*
|
|
* The current DMA TX buffer has been sent.
|
|
* Try to queue up another DMA buffer.
|
|
*/
|
|
static void pl011_dma_tx_callback(void *data)
|
|
{
|
|
struct uart_amba_port *uap = data;
|
|
struct pl011_dmatx_data *dmatx = &uap->dmatx;
|
|
unsigned long flags;
|
|
u16 dmacr;
|
|
|
|
spin_lock_irqsave(&uap->port.lock, flags);
|
|
if (uap->dmatx.queued)
|
|
dma_unmap_sg(dmatx->chan->device->dev, &dmatx->sg, 1,
|
|
DMA_TO_DEVICE);
|
|
|
|
dmacr = uap->dmacr;
|
|
uap->dmacr = dmacr & ~UART011_TXDMAE;
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
|
|
/*
|
|
* If TX DMA was disabled, it means that we've stopped the DMA for
|
|
* some reason (eg, XOFF received, or we want to send an X-char.)
|
|
*
|
|
* Note: we need to be careful here of a potential race between DMA
|
|
* and the rest of the driver - if the driver disables TX DMA while
|
|
* a TX buffer completing, we must update the tx queued status to
|
|
* get further refills (hence we check dmacr).
|
|
*/
|
|
if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) ||
|
|
uart_circ_empty(&uap->port.state->xmit)) {
|
|
uap->dmatx.queued = false;
|
|
spin_unlock_irqrestore(&uap->port.lock, flags);
|
|
return;
|
|
}
|
|
|
|
if (pl011_dma_tx_refill(uap) <= 0)
|
|
/*
|
|
* We didn't queue a DMA buffer for some reason, but we
|
|
* have data pending to be sent. Re-enable the TX IRQ.
|
|
*/
|
|
pl011_start_tx_pio(uap);
|
|
|
|
spin_unlock_irqrestore(&uap->port.lock, flags);
|
|
}
|
|
|
|
/*
|
|
* Try to refill the TX DMA buffer.
|
|
* Locking: called with port lock held and IRQs disabled.
|
|
* Returns:
|
|
* 1 if we queued up a TX DMA buffer.
|
|
* 0 if we didn't want to handle this by DMA
|
|
* <0 on error
|
|
*/
|
|
static int pl011_dma_tx_refill(struct uart_amba_port *uap)
|
|
{
|
|
struct pl011_dmatx_data *dmatx = &uap->dmatx;
|
|
struct dma_chan *chan = dmatx->chan;
|
|
struct dma_device *dma_dev = chan->device;
|
|
struct dma_async_tx_descriptor *desc;
|
|
struct circ_buf *xmit = &uap->port.state->xmit;
|
|
unsigned int count;
|
|
|
|
/*
|
|
* Try to avoid the overhead involved in using DMA if the
|
|
* transaction fits in the first half of the FIFO, by using
|
|
* the standard interrupt handling. This ensures that we
|
|
* issue a uart_write_wakeup() at the appropriate time.
|
|
*/
|
|
count = uart_circ_chars_pending(xmit);
|
|
if (count < (uap->fifosize >> 1)) {
|
|
uap->dmatx.queued = false;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Bodge: don't send the last character by DMA, as this
|
|
* will prevent XON from notifying us to restart DMA.
|
|
*/
|
|
count -= 1;
|
|
|
|
/* Else proceed to copy the TX chars to the DMA buffer and fire DMA */
|
|
if (count > PL011_DMA_BUFFER_SIZE)
|
|
count = PL011_DMA_BUFFER_SIZE;
|
|
|
|
if (xmit->tail < xmit->head)
|
|
memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count);
|
|
else {
|
|
size_t first = UART_XMIT_SIZE - xmit->tail;
|
|
size_t second;
|
|
|
|
if (first > count)
|
|
first = count;
|
|
second = count - first;
|
|
|
|
memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first);
|
|
if (second)
|
|
memcpy(&dmatx->buf[first], &xmit->buf[0], second);
|
|
}
|
|
|
|
dmatx->sg.length = count;
|
|
|
|
if (dma_map_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE) != 1) {
|
|
uap->dmatx.queued = false;
|
|
dev_dbg(uap->port.dev, "unable to map TX DMA\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
desc = dmaengine_prep_slave_sg(chan, &dmatx->sg, 1, DMA_MEM_TO_DEV,
|
|
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
|
|
if (!desc) {
|
|
dma_unmap_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE);
|
|
uap->dmatx.queued = false;
|
|
/*
|
|
* If DMA cannot be used right now, we complete this
|
|
* transaction via IRQ and let the TTY layer retry.
|
|
*/
|
|
dev_dbg(uap->port.dev, "TX DMA busy\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* Some data to go along to the callback */
|
|
desc->callback = pl011_dma_tx_callback;
|
|
desc->callback_param = uap;
|
|
|
|
/* All errors should happen at prepare time */
|
|
dmaengine_submit(desc);
|
|
|
|
/* Fire the DMA transaction */
|
|
dma_dev->device_issue_pending(chan);
|
|
|
|
uap->dmacr |= UART011_TXDMAE;
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
uap->dmatx.queued = true;
|
|
|
|
/*
|
|
* Now we know that DMA will fire, so advance the ring buffer
|
|
* with the stuff we just dispatched.
|
|
*/
|
|
xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
|
|
uap->port.icount.tx += count;
|
|
|
|
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
|
|
uart_write_wakeup(&uap->port);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* We received a transmit interrupt without a pending X-char but with
|
|
* pending characters.
|
|
* Locking: called with port lock held and IRQs disabled.
|
|
* Returns:
|
|
* false if we want to use PIO to transmit
|
|
* true if we queued a DMA buffer
|
|
*/
|
|
static bool pl011_dma_tx_irq(struct uart_amba_port *uap)
|
|
{
|
|
if (!uap->using_tx_dma)
|
|
return false;
|
|
|
|
/*
|
|
* If we already have a TX buffer queued, but received a
|
|
* TX interrupt, it will be because we've just sent an X-char.
|
|
* Ensure the TX DMA is enabled and the TX IRQ is disabled.
|
|
*/
|
|
if (uap->dmatx.queued) {
|
|
uap->dmacr |= UART011_TXDMAE;
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
uap->im &= ~UART011_TXIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* We don't have a TX buffer queued, so try to queue one.
|
|
* If we successfully queued a buffer, mask the TX IRQ.
|
|
*/
|
|
if (pl011_dma_tx_refill(uap) > 0) {
|
|
uap->im &= ~UART011_TXIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Stop the DMA transmit (eg, due to received XOFF).
|
|
* Locking: called with port lock held and IRQs disabled.
|
|
*/
|
|
static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
|
|
{
|
|
if (uap->dmatx.queued) {
|
|
uap->dmacr &= ~UART011_TXDMAE;
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Try to start a DMA transmit, or in the case of an XON/OFF
|
|
* character queued for send, try to get that character out ASAP.
|
|
* Locking: called with port lock held and IRQs disabled.
|
|
* Returns:
|
|
* false if we want the TX IRQ to be enabled
|
|
* true if we have a buffer queued
|
|
*/
|
|
static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
|
|
{
|
|
u16 dmacr;
|
|
|
|
if (!uap->using_tx_dma)
|
|
return false;
|
|
|
|
if (!uap->port.x_char) {
|
|
/* no X-char, try to push chars out in DMA mode */
|
|
bool ret = true;
|
|
|
|
if (!uap->dmatx.queued) {
|
|
if (pl011_dma_tx_refill(uap) > 0) {
|
|
uap->im &= ~UART011_TXIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
} else
|
|
ret = false;
|
|
} else if (!(uap->dmacr & UART011_TXDMAE)) {
|
|
uap->dmacr |= UART011_TXDMAE;
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* We have an X-char to send. Disable DMA to prevent it loading
|
|
* the TX fifo, and then see if we can stuff it into the FIFO.
|
|
*/
|
|
dmacr = uap->dmacr;
|
|
uap->dmacr &= ~UART011_TXDMAE;
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
|
|
if (pl011_read(uap, REG_FR) & UART01x_FR_TXFF) {
|
|
/*
|
|
* No space in the FIFO, so enable the transmit interrupt
|
|
* so we know when there is space. Note that once we've
|
|
* loaded the character, we should just re-enable DMA.
|
|
*/
|
|
return false;
|
|
}
|
|
|
|
pl011_write(uap->port.x_char, uap, REG_DR);
|
|
uap->port.icount.tx++;
|
|
uap->port.x_char = 0;
|
|
|
|
/* Success - restore the DMA state */
|
|
uap->dmacr = dmacr;
|
|
pl011_write(dmacr, uap, REG_DMACR);
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Flush the transmit buffer.
|
|
* Locking: called with port lock held and IRQs disabled.
|
|
*/
|
|
static void pl011_dma_flush_buffer(struct uart_port *port)
|
|
__releases(&uap->port.lock)
|
|
__acquires(&uap->port.lock)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
if (!uap->using_tx_dma)
|
|
return;
|
|
|
|
dmaengine_terminate_async(uap->dmatx.chan);
|
|
|
|
if (uap->dmatx.queued) {
|
|
dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1,
|
|
DMA_TO_DEVICE);
|
|
uap->dmatx.queued = false;
|
|
uap->dmacr &= ~UART011_TXDMAE;
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
}
|
|
}
|
|
|
|
static void pl011_dma_rx_callback(void *data);
|
|
|
|
static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
|
|
{
|
|
struct dma_chan *rxchan = uap->dmarx.chan;
|
|
struct pl011_dmarx_data *dmarx = &uap->dmarx;
|
|
struct dma_async_tx_descriptor *desc;
|
|
struct pl011_sgbuf *sgbuf;
|
|
|
|
if (!rxchan)
|
|
return -EIO;
|
|
|
|
/* Start the RX DMA job */
|
|
sgbuf = uap->dmarx.use_buf_b ?
|
|
&uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
|
|
desc = dmaengine_prep_slave_sg(rxchan, &sgbuf->sg, 1,
|
|
DMA_DEV_TO_MEM,
|
|
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
|
|
/*
|
|
* If the DMA engine is busy and cannot prepare a
|
|
* channel, no big deal, the driver will fall back
|
|
* to interrupt mode as a result of this error code.
|
|
*/
|
|
if (!desc) {
|
|
uap->dmarx.running = false;
|
|
dmaengine_terminate_all(rxchan);
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* Some data to go along to the callback */
|
|
desc->callback = pl011_dma_rx_callback;
|
|
desc->callback_param = uap;
|
|
dmarx->cookie = dmaengine_submit(desc);
|
|
dma_async_issue_pending(rxchan);
|
|
|
|
uap->dmacr |= UART011_RXDMAE;
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
uap->dmarx.running = true;
|
|
|
|
uap->im &= ~UART011_RXIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This is called when either the DMA job is complete, or
|
|
* the FIFO timeout interrupt occurred. This must be called
|
|
* with the port spinlock uap->port.lock held.
|
|
*/
|
|
static void pl011_dma_rx_chars(struct uart_amba_port *uap,
|
|
u32 pending, bool use_buf_b,
|
|
bool readfifo)
|
|
{
|
|
struct tty_port *port = &uap->port.state->port;
|
|
struct pl011_sgbuf *sgbuf = use_buf_b ?
|
|
&uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
|
|
int dma_count = 0;
|
|
u32 fifotaken = 0; /* only used for vdbg() */
|
|
|
|
struct pl011_dmarx_data *dmarx = &uap->dmarx;
|
|
int dmataken = 0;
|
|
|
|
if (uap->dmarx.poll_rate) {
|
|
/* The data can be taken by polling */
|
|
dmataken = sgbuf->sg.length - dmarx->last_residue;
|
|
/* Recalculate the pending size */
|
|
if (pending >= dmataken)
|
|
pending -= dmataken;
|
|
}
|
|
|
|
/* Pick the remain data from the DMA */
|
|
if (pending) {
|
|
|
|
/*
|
|
* First take all chars in the DMA pipe, then look in the FIFO.
|
|
* Note that tty_insert_flip_buf() tries to take as many chars
|
|
* as it can.
|
|
*/
|
|
dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken,
|
|
pending);
|
|
|
|
uap->port.icount.rx += dma_count;
|
|
if (dma_count < pending)
|
|
dev_warn(uap->port.dev,
|
|
"couldn't insert all characters (TTY is full?)\n");
|
|
}
|
|
|
|
/* Reset the last_residue for Rx DMA poll */
|
|
if (uap->dmarx.poll_rate)
|
|
dmarx->last_residue = sgbuf->sg.length;
|
|
|
|
/*
|
|
* Only continue with trying to read the FIFO if all DMA chars have
|
|
* been taken first.
|
|
*/
|
|
if (dma_count == pending && readfifo) {
|
|
/* Clear any error flags */
|
|
pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS |
|
|
UART011_FEIS, uap, REG_ICR);
|
|
|
|
/*
|
|
* If we read all the DMA'd characters, and we had an
|
|
* incomplete buffer, that could be due to an rx error, or
|
|
* maybe we just timed out. Read any pending chars and check
|
|
* the error status.
|
|
*
|
|
* Error conditions will only occur in the FIFO, these will
|
|
* trigger an immediate interrupt and stop the DMA job, so we
|
|
* will always find the error in the FIFO, never in the DMA
|
|
* buffer.
|
|
*/
|
|
fifotaken = pl011_fifo_to_tty(uap);
|
|
}
|
|
|
|
dev_vdbg(uap->port.dev,
|
|
"Took %d chars from DMA buffer and %d chars from the FIFO\n",
|
|
dma_count, fifotaken);
|
|
tty_flip_buffer_push(port);
|
|
}
|
|
|
|
static void pl011_dma_rx_irq(struct uart_amba_port *uap)
|
|
{
|
|
struct pl011_dmarx_data *dmarx = &uap->dmarx;
|
|
struct dma_chan *rxchan = dmarx->chan;
|
|
struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ?
|
|
&dmarx->sgbuf_b : &dmarx->sgbuf_a;
|
|
size_t pending;
|
|
struct dma_tx_state state;
|
|
enum dma_status dmastat;
|
|
|
|
/*
|
|
* Pause the transfer so we can trust the current counter,
|
|
* do this before we pause the PL011 block, else we may
|
|
* overflow the FIFO.
|
|
*/
|
|
if (dmaengine_pause(rxchan))
|
|
dev_err(uap->port.dev, "unable to pause DMA transfer\n");
|
|
dmastat = rxchan->device->device_tx_status(rxchan,
|
|
dmarx->cookie, &state);
|
|
if (dmastat != DMA_PAUSED)
|
|
dev_err(uap->port.dev, "unable to pause DMA transfer\n");
|
|
|
|
/* Disable RX DMA - incoming data will wait in the FIFO */
|
|
uap->dmacr &= ~UART011_RXDMAE;
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
uap->dmarx.running = false;
|
|
|
|
pending = sgbuf->sg.length - state.residue;
|
|
BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
|
|
/* Then we terminate the transfer - we now know our residue */
|
|
dmaengine_terminate_all(rxchan);
|
|
|
|
/*
|
|
* This will take the chars we have so far and insert
|
|
* into the framework.
|
|
*/
|
|
pl011_dma_rx_chars(uap, pending, dmarx->use_buf_b, true);
|
|
|
|
/* Switch buffer & re-trigger DMA job */
|
|
dmarx->use_buf_b = !dmarx->use_buf_b;
|
|
if (pl011_dma_rx_trigger_dma(uap)) {
|
|
dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
|
|
"fall back to interrupt mode\n");
|
|
uap->im |= UART011_RXIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
}
|
|
}
|
|
|
|
static void pl011_dma_rx_callback(void *data)
|
|
{
|
|
struct uart_amba_port *uap = data;
|
|
struct pl011_dmarx_data *dmarx = &uap->dmarx;
|
|
struct dma_chan *rxchan = dmarx->chan;
|
|
bool lastbuf = dmarx->use_buf_b;
|
|
struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ?
|
|
&dmarx->sgbuf_b : &dmarx->sgbuf_a;
|
|
size_t pending;
|
|
struct dma_tx_state state;
|
|
int ret;
|
|
|
|
/*
|
|
* This completion interrupt occurs typically when the
|
|
* RX buffer is totally stuffed but no timeout has yet
|
|
* occurred. When that happens, we just want the RX
|
|
* routine to flush out the secondary DMA buffer while
|
|
* we immediately trigger the next DMA job.
|
|
*/
|
|
spin_lock_irq(&uap->port.lock);
|
|
/*
|
|
* Rx data can be taken by the UART interrupts during
|
|
* the DMA irq handler. So we check the residue here.
|
|
*/
|
|
rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
|
|
pending = sgbuf->sg.length - state.residue;
|
|
BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
|
|
/* Then we terminate the transfer - we now know our residue */
|
|
dmaengine_terminate_all(rxchan);
|
|
|
|
uap->dmarx.running = false;
|
|
dmarx->use_buf_b = !lastbuf;
|
|
ret = pl011_dma_rx_trigger_dma(uap);
|
|
|
|
pl011_dma_rx_chars(uap, pending, lastbuf, false);
|
|
spin_unlock_irq(&uap->port.lock);
|
|
/*
|
|
* Do this check after we picked the DMA chars so we don't
|
|
* get some IRQ immediately from RX.
|
|
*/
|
|
if (ret) {
|
|
dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
|
|
"fall back to interrupt mode\n");
|
|
uap->im |= UART011_RXIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Stop accepting received characters, when we're shutting down or
|
|
* suspending this port.
|
|
* Locking: called with port lock held and IRQs disabled.
|
|
*/
|
|
static inline void pl011_dma_rx_stop(struct uart_amba_port *uap)
|
|
{
|
|
/* FIXME. Just disable the DMA enable */
|
|
uap->dmacr &= ~UART011_RXDMAE;
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
}
|
|
|
|
/*
|
|
* Timer handler for Rx DMA polling.
|
|
* Every polling, It checks the residue in the dma buffer and transfer
|
|
* data to the tty. Also, last_residue is updated for the next polling.
|
|
*/
|
|
static void pl011_dma_rx_poll(struct timer_list *t)
|
|
{
|
|
struct uart_amba_port *uap = from_timer(uap, t, dmarx.timer);
|
|
struct tty_port *port = &uap->port.state->port;
|
|
struct pl011_dmarx_data *dmarx = &uap->dmarx;
|
|
struct dma_chan *rxchan = uap->dmarx.chan;
|
|
unsigned long flags;
|
|
unsigned int dmataken = 0;
|
|
unsigned int size = 0;
|
|
struct pl011_sgbuf *sgbuf;
|
|
int dma_count;
|
|
struct dma_tx_state state;
|
|
|
|
sgbuf = dmarx->use_buf_b ? &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
|
|
rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
|
|
if (likely(state.residue < dmarx->last_residue)) {
|
|
dmataken = sgbuf->sg.length - dmarx->last_residue;
|
|
size = dmarx->last_residue - state.residue;
|
|
dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken,
|
|
size);
|
|
if (dma_count == size)
|
|
dmarx->last_residue = state.residue;
|
|
dmarx->last_jiffies = jiffies;
|
|
}
|
|
tty_flip_buffer_push(port);
|
|
|
|
/*
|
|
* If no data is received in poll_timeout, the driver will fall back
|
|
* to interrupt mode. We will retrigger DMA at the first interrupt.
|
|
*/
|
|
if (jiffies_to_msecs(jiffies - dmarx->last_jiffies)
|
|
> uap->dmarx.poll_timeout) {
|
|
|
|
spin_lock_irqsave(&uap->port.lock, flags);
|
|
pl011_dma_rx_stop(uap);
|
|
uap->im |= UART011_RXIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
spin_unlock_irqrestore(&uap->port.lock, flags);
|
|
|
|
uap->dmarx.running = false;
|
|
dmaengine_terminate_all(rxchan);
|
|
del_timer(&uap->dmarx.timer);
|
|
} else {
|
|
mod_timer(&uap->dmarx.timer,
|
|
jiffies + msecs_to_jiffies(uap->dmarx.poll_rate));
|
|
}
|
|
}
|
|
|
|
static void pl011_dma_startup(struct uart_amba_port *uap)
|
|
{
|
|
int ret;
|
|
|
|
if (!uap->dma_probed)
|
|
pl011_dma_probe(uap);
|
|
|
|
if (!uap->dmatx.chan)
|
|
return;
|
|
|
|
uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL | __GFP_DMA);
|
|
if (!uap->dmatx.buf) {
|
|
dev_err(uap->port.dev, "no memory for DMA TX buffer\n");
|
|
uap->port.fifosize = uap->fifosize;
|
|
return;
|
|
}
|
|
|
|
sg_init_one(&uap->dmatx.sg, uap->dmatx.buf, PL011_DMA_BUFFER_SIZE);
|
|
|
|
/* The DMA buffer is now the FIFO the TTY subsystem can use */
|
|
uap->port.fifosize = PL011_DMA_BUFFER_SIZE;
|
|
uap->using_tx_dma = true;
|
|
|
|
if (!uap->dmarx.chan)
|
|
goto skip_rx;
|
|
|
|
/* Allocate and map DMA RX buffers */
|
|
ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_a,
|
|
DMA_FROM_DEVICE);
|
|
if (ret) {
|
|
dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
|
|
"RX buffer A", ret);
|
|
goto skip_rx;
|
|
}
|
|
|
|
ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_b,
|
|
DMA_FROM_DEVICE);
|
|
if (ret) {
|
|
dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
|
|
"RX buffer B", ret);
|
|
pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a,
|
|
DMA_FROM_DEVICE);
|
|
goto skip_rx;
|
|
}
|
|
|
|
uap->using_rx_dma = true;
|
|
|
|
skip_rx:
|
|
/* Turn on DMA error (RX/TX will be enabled on demand) */
|
|
uap->dmacr |= UART011_DMAONERR;
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
|
|
/*
|
|
* ST Micro variants has some specific dma burst threshold
|
|
* compensation. Set this to 16 bytes, so burst will only
|
|
* be issued above/below 16 bytes.
|
|
*/
|
|
if (uap->vendor->dma_threshold)
|
|
pl011_write(ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16,
|
|
uap, REG_ST_DMAWM);
|
|
|
|
if (uap->using_rx_dma) {
|
|
if (pl011_dma_rx_trigger_dma(uap))
|
|
dev_dbg(uap->port.dev, "could not trigger initial "
|
|
"RX DMA job, fall back to interrupt mode\n");
|
|
if (uap->dmarx.poll_rate) {
|
|
timer_setup(&uap->dmarx.timer, pl011_dma_rx_poll, 0);
|
|
mod_timer(&uap->dmarx.timer,
|
|
jiffies +
|
|
msecs_to_jiffies(uap->dmarx.poll_rate));
|
|
uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE;
|
|
uap->dmarx.last_jiffies = jiffies;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void pl011_dma_shutdown(struct uart_amba_port *uap)
|
|
{
|
|
if (!(uap->using_tx_dma || uap->using_rx_dma))
|
|
return;
|
|
|
|
/* Disable RX and TX DMA */
|
|
while (pl011_read(uap, REG_FR) & uap->vendor->fr_busy)
|
|
cpu_relax();
|
|
|
|
spin_lock_irq(&uap->port.lock);
|
|
uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE);
|
|
pl011_write(uap->dmacr, uap, REG_DMACR);
|
|
spin_unlock_irq(&uap->port.lock);
|
|
|
|
if (uap->using_tx_dma) {
|
|
/* In theory, this should already be done by pl011_dma_flush_buffer */
|
|
dmaengine_terminate_all(uap->dmatx.chan);
|
|
if (uap->dmatx.queued) {
|
|
dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1,
|
|
DMA_TO_DEVICE);
|
|
uap->dmatx.queued = false;
|
|
}
|
|
|
|
kfree(uap->dmatx.buf);
|
|
uap->using_tx_dma = false;
|
|
}
|
|
|
|
if (uap->using_rx_dma) {
|
|
dmaengine_terminate_all(uap->dmarx.chan);
|
|
/* Clean up the RX DMA */
|
|
pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, DMA_FROM_DEVICE);
|
|
pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_b, DMA_FROM_DEVICE);
|
|
if (uap->dmarx.poll_rate)
|
|
del_timer_sync(&uap->dmarx.timer);
|
|
uap->using_rx_dma = false;
|
|
}
|
|
}
|
|
|
|
static inline bool pl011_dma_rx_available(struct uart_amba_port *uap)
|
|
{
|
|
return uap->using_rx_dma;
|
|
}
|
|
|
|
static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
|
|
{
|
|
return uap->using_rx_dma && uap->dmarx.running;
|
|
}
|
|
|
|
#else
|
|
/* Blank functions if the DMA engine is not available */
|
|
static inline void pl011_dma_remove(struct uart_amba_port *uap)
|
|
{
|
|
}
|
|
|
|
static inline void pl011_dma_startup(struct uart_amba_port *uap)
|
|
{
|
|
}
|
|
|
|
static inline void pl011_dma_shutdown(struct uart_amba_port *uap)
|
|
{
|
|
}
|
|
|
|
static inline bool pl011_dma_tx_irq(struct uart_amba_port *uap)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
|
|
{
|
|
}
|
|
|
|
static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline void pl011_dma_rx_irq(struct uart_amba_port *uap)
|
|
{
|
|
}
|
|
|
|
static inline void pl011_dma_rx_stop(struct uart_amba_port *uap)
|
|
{
|
|
}
|
|
|
|
static inline int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
|
|
{
|
|
return -EIO;
|
|
}
|
|
|
|
static inline bool pl011_dma_rx_available(struct uart_amba_port *uap)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
#define pl011_dma_flush_buffer NULL
|
|
#endif
|
|
|
|
static void pl011_rs485_tx_stop(struct uart_amba_port *uap)
|
|
{
|
|
struct uart_port *port = &uap->port;
|
|
int i = 0;
|
|
u32 cr;
|
|
|
|
/* Wait until hardware tx queue is empty */
|
|
while (!pl011_tx_empty(port)) {
|
|
if (i == port->fifosize) {
|
|
dev_warn(port->dev,
|
|
"timeout while draining hardware tx queue\n");
|
|
break;
|
|
}
|
|
|
|
udelay(uap->rs485_tx_drain_interval);
|
|
i++;
|
|
}
|
|
|
|
if (port->rs485.delay_rts_after_send)
|
|
mdelay(port->rs485.delay_rts_after_send);
|
|
|
|
cr = pl011_read(uap, REG_CR);
|
|
|
|
if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
|
|
cr &= ~UART011_CR_RTS;
|
|
else
|
|
cr |= UART011_CR_RTS;
|
|
|
|
/* Disable the transmitter and reenable the transceiver */
|
|
cr &= ~UART011_CR_TXE;
|
|
cr |= UART011_CR_RXE;
|
|
pl011_write(cr, uap, REG_CR);
|
|
|
|
uap->rs485_tx_started = false;
|
|
}
|
|
|
|
static void pl011_stop_tx(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
uap->im &= ~UART011_TXIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
pl011_dma_tx_stop(uap);
|
|
|
|
if ((port->rs485.flags & SER_RS485_ENABLED) && uap->rs485_tx_started)
|
|
pl011_rs485_tx_stop(uap);
|
|
}
|
|
|
|
static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq);
|
|
|
|
/* Start TX with programmed I/O only (no DMA) */
|
|
static void pl011_start_tx_pio(struct uart_amba_port *uap)
|
|
{
|
|
if (pl011_tx_chars(uap, false)) {
|
|
uap->im |= UART011_TXIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
}
|
|
}
|
|
|
|
static void pl011_start_tx(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
if (!pl011_dma_tx_start(uap))
|
|
pl011_start_tx_pio(uap);
|
|
}
|
|
|
|
static void pl011_stop_rx(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
uap->im &= ~(UART011_RXIM|UART011_RTIM|UART011_FEIM|
|
|
UART011_PEIM|UART011_BEIM|UART011_OEIM);
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
|
|
pl011_dma_rx_stop(uap);
|
|
}
|
|
|
|
static void pl011_enable_ms(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
uap->im |= UART011_RIMIM|UART011_CTSMIM|UART011_DCDMIM|UART011_DSRMIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
}
|
|
|
|
static void pl011_rx_chars(struct uart_amba_port *uap)
|
|
__releases(&uap->port.lock)
|
|
__acquires(&uap->port.lock)
|
|
{
|
|
pl011_fifo_to_tty(uap);
|
|
|
|
spin_unlock(&uap->port.lock);
|
|
tty_flip_buffer_push(&uap->port.state->port);
|
|
/*
|
|
* If we were temporarily out of DMA mode for a while,
|
|
* attempt to switch back to DMA mode again.
|
|
*/
|
|
if (pl011_dma_rx_available(uap)) {
|
|
if (pl011_dma_rx_trigger_dma(uap)) {
|
|
dev_dbg(uap->port.dev, "could not trigger RX DMA job "
|
|
"fall back to interrupt mode again\n");
|
|
uap->im |= UART011_RXIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
} else {
|
|
#ifdef CONFIG_DMA_ENGINE
|
|
/* Start Rx DMA poll */
|
|
if (uap->dmarx.poll_rate) {
|
|
uap->dmarx.last_jiffies = jiffies;
|
|
uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE;
|
|
mod_timer(&uap->dmarx.timer,
|
|
jiffies +
|
|
msecs_to_jiffies(uap->dmarx.poll_rate));
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
spin_lock(&uap->port.lock);
|
|
}
|
|
|
|
static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c,
|
|
bool from_irq)
|
|
{
|
|
if (unlikely(!from_irq) &&
|
|
pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
|
|
return false; /* unable to transmit character */
|
|
|
|
pl011_write(c, uap, REG_DR);
|
|
uap->port.icount.tx++;
|
|
|
|
return true;
|
|
}
|
|
|
|
static void pl011_rs485_tx_start(struct uart_amba_port *uap)
|
|
{
|
|
struct uart_port *port = &uap->port;
|
|
u32 cr;
|
|
|
|
/* Enable transmitter */
|
|
cr = pl011_read(uap, REG_CR);
|
|
cr |= UART011_CR_TXE;
|
|
|
|
/* Disable receiver if half-duplex */
|
|
if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
|
|
cr &= ~UART011_CR_RXE;
|
|
|
|
if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
|
|
cr &= ~UART011_CR_RTS;
|
|
else
|
|
cr |= UART011_CR_RTS;
|
|
|
|
pl011_write(cr, uap, REG_CR);
|
|
|
|
if (port->rs485.delay_rts_before_send)
|
|
mdelay(port->rs485.delay_rts_before_send);
|
|
|
|
uap->rs485_tx_started = true;
|
|
}
|
|
|
|
/* Returns true if tx interrupts have to be (kept) enabled */
|
|
static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
|
|
{
|
|
struct circ_buf *xmit = &uap->port.state->xmit;
|
|
int count = uap->fifosize >> 1;
|
|
|
|
if (uap->port.x_char) {
|
|
if (!pl011_tx_char(uap, uap->port.x_char, from_irq))
|
|
return true;
|
|
uap->port.x_char = 0;
|
|
--count;
|
|
}
|
|
if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
|
|
pl011_stop_tx(&uap->port);
|
|
return false;
|
|
}
|
|
|
|
if ((uap->port.rs485.flags & SER_RS485_ENABLED) &&
|
|
!uap->rs485_tx_started)
|
|
pl011_rs485_tx_start(uap);
|
|
|
|
/* If we are using DMA mode, try to send some characters. */
|
|
if (pl011_dma_tx_irq(uap))
|
|
return true;
|
|
|
|
do {
|
|
if (likely(from_irq) && count-- == 0)
|
|
break;
|
|
|
|
if (!pl011_tx_char(uap, xmit->buf[xmit->tail], from_irq))
|
|
break;
|
|
|
|
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
|
|
} while (!uart_circ_empty(xmit));
|
|
|
|
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
|
|
uart_write_wakeup(&uap->port);
|
|
|
|
if (uart_circ_empty(xmit)) {
|
|
pl011_stop_tx(&uap->port);
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static void pl011_modem_status(struct uart_amba_port *uap)
|
|
{
|
|
unsigned int status, delta;
|
|
|
|
status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY;
|
|
|
|
delta = status ^ uap->old_status;
|
|
uap->old_status = status;
|
|
|
|
if (!delta)
|
|
return;
|
|
|
|
if (delta & UART01x_FR_DCD)
|
|
uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
|
|
|
|
if (delta & uap->vendor->fr_dsr)
|
|
uap->port.icount.dsr++;
|
|
|
|
if (delta & uap->vendor->fr_cts)
|
|
uart_handle_cts_change(&uap->port,
|
|
status & uap->vendor->fr_cts);
|
|
|
|
wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
|
|
}
|
|
|
|
static void check_apply_cts_event_workaround(struct uart_amba_port *uap)
|
|
{
|
|
if (!uap->vendor->cts_event_workaround)
|
|
return;
|
|
|
|
/* workaround to make sure that all bits are unlocked.. */
|
|
pl011_write(0x00, uap, REG_ICR);
|
|
|
|
/*
|
|
* WA: introduce 26ns(1 uart clk) delay before W1C;
|
|
* single apb access will incur 2 pclk(133.12Mhz) delay,
|
|
* so add 2 dummy reads
|
|
*/
|
|
pl011_read(uap, REG_ICR);
|
|
pl011_read(uap, REG_ICR);
|
|
}
|
|
|
|
static irqreturn_t pl011_int(int irq, void *dev_id)
|
|
{
|
|
struct uart_amba_port *uap = dev_id;
|
|
unsigned long flags;
|
|
unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
|
|
int handled = 0;
|
|
|
|
spin_lock_irqsave(&uap->port.lock, flags);
|
|
status = pl011_read(uap, REG_RIS) & uap->im;
|
|
if (status) {
|
|
do {
|
|
check_apply_cts_event_workaround(uap);
|
|
|
|
pl011_write(status & ~(UART011_TXIS|UART011_RTIS|
|
|
UART011_RXIS),
|
|
uap, REG_ICR);
|
|
|
|
if (status & (UART011_RTIS|UART011_RXIS)) {
|
|
if (pl011_dma_rx_running(uap))
|
|
pl011_dma_rx_irq(uap);
|
|
else
|
|
pl011_rx_chars(uap);
|
|
}
|
|
if (status & (UART011_DSRMIS|UART011_DCDMIS|
|
|
UART011_CTSMIS|UART011_RIMIS))
|
|
pl011_modem_status(uap);
|
|
if (status & UART011_TXIS)
|
|
pl011_tx_chars(uap, true);
|
|
|
|
if (pass_counter-- == 0)
|
|
break;
|
|
|
|
status = pl011_read(uap, REG_RIS) & uap->im;
|
|
} while (status != 0);
|
|
handled = 1;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&uap->port.lock, flags);
|
|
|
|
return IRQ_RETVAL(handled);
|
|
}
|
|
|
|
static unsigned int pl011_tx_empty(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
/* Allow feature register bits to be inverted to work around errata */
|
|
unsigned int status = pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr;
|
|
|
|
return status & (uap->vendor->fr_busy | UART01x_FR_TXFF) ?
|
|
0 : TIOCSER_TEMT;
|
|
}
|
|
|
|
static unsigned int pl011_get_mctrl(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
unsigned int result = 0;
|
|
unsigned int status = pl011_read(uap, REG_FR);
|
|
|
|
#define TIOCMBIT(uartbit, tiocmbit) \
|
|
if (status & uartbit) \
|
|
result |= tiocmbit
|
|
|
|
TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR);
|
|
TIOCMBIT(uap->vendor->fr_dsr, TIOCM_DSR);
|
|
TIOCMBIT(uap->vendor->fr_cts, TIOCM_CTS);
|
|
TIOCMBIT(uap->vendor->fr_ri, TIOCM_RNG);
|
|
#undef TIOCMBIT
|
|
return result;
|
|
}
|
|
|
|
static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
unsigned int cr;
|
|
|
|
if (port->rs485.flags & SER_RS485_ENABLED)
|
|
mctrl &= ~TIOCM_RTS;
|
|
|
|
cr = pl011_read(uap, REG_CR);
|
|
|
|
#define TIOCMBIT(tiocmbit, uartbit) \
|
|
if (mctrl & tiocmbit) \
|
|
cr |= uartbit; \
|
|
else \
|
|
cr &= ~uartbit
|
|
|
|
TIOCMBIT(TIOCM_RTS, UART011_CR_RTS);
|
|
TIOCMBIT(TIOCM_DTR, UART011_CR_DTR);
|
|
TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1);
|
|
TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2);
|
|
TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE);
|
|
|
|
if (port->status & UPSTAT_AUTORTS) {
|
|
/* We need to disable auto-RTS if we want to turn RTS off */
|
|
TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN);
|
|
}
|
|
#undef TIOCMBIT
|
|
|
|
pl011_write(cr, uap, REG_CR);
|
|
}
|
|
|
|
static void pl011_break_ctl(struct uart_port *port, int break_state)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
unsigned long flags;
|
|
unsigned int lcr_h;
|
|
|
|
spin_lock_irqsave(&uap->port.lock, flags);
|
|
lcr_h = pl011_read(uap, REG_LCRH_TX);
|
|
if (break_state == -1)
|
|
lcr_h |= UART01x_LCRH_BRK;
|
|
else
|
|
lcr_h &= ~UART01x_LCRH_BRK;
|
|
pl011_write(lcr_h, uap, REG_LCRH_TX);
|
|
spin_unlock_irqrestore(&uap->port.lock, flags);
|
|
}
|
|
|
|
#ifdef CONFIG_CONSOLE_POLL
|
|
|
|
static void pl011_quiesce_irqs(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
pl011_write(pl011_read(uap, REG_MIS), uap, REG_ICR);
|
|
/*
|
|
* There is no way to clear TXIM as this is "ready to transmit IRQ", so
|
|
* we simply mask it. start_tx() will unmask it.
|
|
*
|
|
* Note we can race with start_tx(), and if the race happens, the
|
|
* polling user might get another interrupt just after we clear it.
|
|
* But it should be OK and can happen even w/o the race, e.g.
|
|
* controller immediately got some new data and raised the IRQ.
|
|
*
|
|
* And whoever uses polling routines assumes that it manages the device
|
|
* (including tx queue), so we're also fine with start_tx()'s caller
|
|
* side.
|
|
*/
|
|
pl011_write(pl011_read(uap, REG_IMSC) & ~UART011_TXIM, uap,
|
|
REG_IMSC);
|
|
}
|
|
|
|
static int pl011_get_poll_char(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
unsigned int status;
|
|
|
|
/*
|
|
* The caller might need IRQs lowered, e.g. if used with KDB NMI
|
|
* debugger.
|
|
*/
|
|
pl011_quiesce_irqs(port);
|
|
|
|
status = pl011_read(uap, REG_FR);
|
|
if (status & UART01x_FR_RXFE)
|
|
return NO_POLL_CHAR;
|
|
|
|
return pl011_read(uap, REG_DR);
|
|
}
|
|
|
|
static void pl011_put_poll_char(struct uart_port *port,
|
|
unsigned char ch)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
|
|
cpu_relax();
|
|
|
|
pl011_write(ch, uap, REG_DR);
|
|
}
|
|
|
|
#endif /* CONFIG_CONSOLE_POLL */
|
|
|
|
static int pl011_hwinit(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
int retval;
|
|
|
|
/* Optionaly enable pins to be muxed in and configured */
|
|
pinctrl_pm_select_default_state(port->dev);
|
|
|
|
/*
|
|
* Try to enable the clock producer.
|
|
*/
|
|
retval = clk_prepare_enable(uap->clk);
|
|
if (retval)
|
|
return retval;
|
|
|
|
uap->port.uartclk = clk_get_rate(uap->clk);
|
|
|
|
/* Clear pending error and receive interrupts */
|
|
pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS |
|
|
UART011_FEIS | UART011_RTIS | UART011_RXIS,
|
|
uap, REG_ICR);
|
|
|
|
/*
|
|
* Save interrupts enable mask, and enable RX interrupts in case if
|
|
* the interrupt is used for NMI entry.
|
|
*/
|
|
uap->im = pl011_read(uap, REG_IMSC);
|
|
pl011_write(UART011_RTIM | UART011_RXIM, uap, REG_IMSC);
|
|
|
|
if (dev_get_platdata(uap->port.dev)) {
|
|
struct amba_pl011_data *plat;
|
|
|
|
plat = dev_get_platdata(uap->port.dev);
|
|
if (plat->init)
|
|
plat->init();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static bool pl011_split_lcrh(const struct uart_amba_port *uap)
|
|
{
|
|
return pl011_reg_to_offset(uap, REG_LCRH_RX) !=
|
|
pl011_reg_to_offset(uap, REG_LCRH_TX);
|
|
}
|
|
|
|
static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h)
|
|
{
|
|
pl011_write(lcr_h, uap, REG_LCRH_RX);
|
|
if (pl011_split_lcrh(uap)) {
|
|
int i;
|
|
/*
|
|
* Wait 10 PCLKs before writing LCRH_TX register,
|
|
* to get this delay write read only register 10 times
|
|
*/
|
|
for (i = 0; i < 10; ++i)
|
|
pl011_write(0xff, uap, REG_MIS);
|
|
pl011_write(lcr_h, uap, REG_LCRH_TX);
|
|
}
|
|
}
|
|
|
|
static int pl011_allocate_irq(struct uart_amba_port *uap)
|
|
{
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
|
|
return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011", uap);
|
|
}
|
|
|
|
/*
|
|
* Enable interrupts, only timeouts when using DMA
|
|
* if initial RX DMA job failed, start in interrupt mode
|
|
* as well.
|
|
*/
|
|
static void pl011_enable_interrupts(struct uart_amba_port *uap)
|
|
{
|
|
unsigned int i;
|
|
|
|
spin_lock_irq(&uap->port.lock);
|
|
|
|
/* Clear out any spuriously appearing RX interrupts */
|
|
pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR);
|
|
|
|
/*
|
|
* RXIS is asserted only when the RX FIFO transitions from below
|
|
* to above the trigger threshold. If the RX FIFO is already
|
|
* full to the threshold this can't happen and RXIS will now be
|
|
* stuck off. Drain the RX FIFO explicitly to fix this:
|
|
*/
|
|
for (i = 0; i < uap->fifosize * 2; ++i) {
|
|
if (pl011_read(uap, REG_FR) & UART01x_FR_RXFE)
|
|
break;
|
|
|
|
pl011_read(uap, REG_DR);
|
|
}
|
|
|
|
uap->im = UART011_RTIM;
|
|
if (!pl011_dma_rx_running(uap))
|
|
uap->im |= UART011_RXIM;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
spin_unlock_irq(&uap->port.lock);
|
|
}
|
|
|
|
static int pl011_startup(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
unsigned int cr;
|
|
int retval;
|
|
|
|
retval = pl011_hwinit(port);
|
|
if (retval)
|
|
goto clk_dis;
|
|
|
|
retval = pl011_allocate_irq(uap);
|
|
if (retval)
|
|
goto clk_dis;
|
|
|
|
pl011_write(uap->vendor->ifls, uap, REG_IFLS);
|
|
|
|
spin_lock_irq(&uap->port.lock);
|
|
|
|
/* restore RTS and DTR */
|
|
cr = uap->old_cr & (UART011_CR_RTS | UART011_CR_DTR);
|
|
cr |= UART01x_CR_UARTEN | UART011_CR_RXE;
|
|
|
|
if (port->rs485.flags & SER_RS485_ENABLED) {
|
|
if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
|
|
cr &= ~UART011_CR_RTS;
|
|
else
|
|
cr |= UART011_CR_RTS;
|
|
} else {
|
|
cr |= UART011_CR_TXE;
|
|
}
|
|
|
|
pl011_write(cr, uap, REG_CR);
|
|
|
|
spin_unlock_irq(&uap->port.lock);
|
|
|
|
/*
|
|
* initialise the old status of the modem signals
|
|
*/
|
|
uap->old_status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY;
|
|
|
|
/* Startup DMA */
|
|
pl011_dma_startup(uap);
|
|
|
|
pl011_enable_interrupts(uap);
|
|
|
|
return 0;
|
|
|
|
clk_dis:
|
|
clk_disable_unprepare(uap->clk);
|
|
return retval;
|
|
}
|
|
|
|
static int sbsa_uart_startup(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
int retval;
|
|
|
|
retval = pl011_hwinit(port);
|
|
if (retval)
|
|
return retval;
|
|
|
|
retval = pl011_allocate_irq(uap);
|
|
if (retval)
|
|
return retval;
|
|
|
|
/* The SBSA UART does not support any modem status lines. */
|
|
uap->old_status = 0;
|
|
|
|
pl011_enable_interrupts(uap);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void pl011_shutdown_channel(struct uart_amba_port *uap,
|
|
unsigned int lcrh)
|
|
{
|
|
unsigned long val;
|
|
|
|
val = pl011_read(uap, lcrh);
|
|
val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
|
|
pl011_write(val, uap, lcrh);
|
|
}
|
|
|
|
/*
|
|
* disable the port. It should not disable RTS and DTR.
|
|
* Also RTS and DTR state should be preserved to restore
|
|
* it during startup().
|
|
*/
|
|
static void pl011_disable_uart(struct uart_amba_port *uap)
|
|
{
|
|
unsigned int cr;
|
|
|
|
uap->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
|
|
spin_lock_irq(&uap->port.lock);
|
|
cr = pl011_read(uap, REG_CR);
|
|
uap->old_cr = cr;
|
|
cr &= UART011_CR_RTS | UART011_CR_DTR;
|
|
cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
|
|
pl011_write(cr, uap, REG_CR);
|
|
spin_unlock_irq(&uap->port.lock);
|
|
|
|
/*
|
|
* disable break condition and fifos
|
|
*/
|
|
pl011_shutdown_channel(uap, REG_LCRH_RX);
|
|
if (pl011_split_lcrh(uap))
|
|
pl011_shutdown_channel(uap, REG_LCRH_TX);
|
|
}
|
|
|
|
static void pl011_disable_interrupts(struct uart_amba_port *uap)
|
|
{
|
|
spin_lock_irq(&uap->port.lock);
|
|
|
|
/* mask all interrupts and clear all pending ones */
|
|
uap->im = 0;
|
|
pl011_write(uap->im, uap, REG_IMSC);
|
|
pl011_write(0xffff, uap, REG_ICR);
|
|
|
|
spin_unlock_irq(&uap->port.lock);
|
|
}
|
|
|
|
static void pl011_shutdown(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
pl011_disable_interrupts(uap);
|
|
|
|
pl011_dma_shutdown(uap);
|
|
|
|
if ((port->rs485.flags & SER_RS485_ENABLED) && uap->rs485_tx_started)
|
|
pl011_rs485_tx_stop(uap);
|
|
|
|
free_irq(uap->port.irq, uap);
|
|
|
|
pl011_disable_uart(uap);
|
|
|
|
/*
|
|
* Shut down the clock producer
|
|
*/
|
|
clk_disable_unprepare(uap->clk);
|
|
/* Optionally let pins go into sleep states */
|
|
pinctrl_pm_select_sleep_state(port->dev);
|
|
|
|
if (dev_get_platdata(uap->port.dev)) {
|
|
struct amba_pl011_data *plat;
|
|
|
|
plat = dev_get_platdata(uap->port.dev);
|
|
if (plat->exit)
|
|
plat->exit();
|
|
}
|
|
|
|
if (uap->port.ops->flush_buffer)
|
|
uap->port.ops->flush_buffer(port);
|
|
}
|
|
|
|
static void sbsa_uart_shutdown(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
pl011_disable_interrupts(uap);
|
|
|
|
free_irq(uap->port.irq, uap);
|
|
|
|
if (uap->port.ops->flush_buffer)
|
|
uap->port.ops->flush_buffer(port);
|
|
}
|
|
|
|
static void
|
|
pl011_setup_status_masks(struct uart_port *port, struct ktermios *termios)
|
|
{
|
|
port->read_status_mask = UART011_DR_OE | 255;
|
|
if (termios->c_iflag & INPCK)
|
|
port->read_status_mask |= UART011_DR_FE | UART011_DR_PE;
|
|
if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
|
|
port->read_status_mask |= UART011_DR_BE;
|
|
|
|
/*
|
|
* Characters to ignore
|
|
*/
|
|
port->ignore_status_mask = 0;
|
|
if (termios->c_iflag & IGNPAR)
|
|
port->ignore_status_mask |= UART011_DR_FE | UART011_DR_PE;
|
|
if (termios->c_iflag & IGNBRK) {
|
|
port->ignore_status_mask |= UART011_DR_BE;
|
|
/*
|
|
* If we're ignoring parity and break indicators,
|
|
* ignore overruns too (for real raw support).
|
|
*/
|
|
if (termios->c_iflag & IGNPAR)
|
|
port->ignore_status_mask |= UART011_DR_OE;
|
|
}
|
|
|
|
/*
|
|
* Ignore all characters if CREAD is not set.
|
|
*/
|
|
if ((termios->c_cflag & CREAD) == 0)
|
|
port->ignore_status_mask |= UART_DUMMY_DR_RX;
|
|
}
|
|
|
|
static void
|
|
pl011_set_termios(struct uart_port *port, struct ktermios *termios,
|
|
struct ktermios *old)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
unsigned int lcr_h, old_cr;
|
|
unsigned long flags;
|
|
unsigned int baud, quot, clkdiv;
|
|
unsigned int bits;
|
|
|
|
if (uap->vendor->oversampling)
|
|
clkdiv = 8;
|
|
else
|
|
clkdiv = 16;
|
|
|
|
/*
|
|
* Ask the core to calculate the divisor for us.
|
|
*/
|
|
baud = uart_get_baud_rate(port, termios, old, 0,
|
|
port->uartclk / clkdiv);
|
|
#ifdef CONFIG_DMA_ENGINE
|
|
/*
|
|
* Adjust RX DMA polling rate with baud rate if not specified.
|
|
*/
|
|
if (uap->dmarx.auto_poll_rate)
|
|
uap->dmarx.poll_rate = DIV_ROUND_UP(10000000, baud);
|
|
#endif
|
|
|
|
if (baud > port->uartclk/16)
|
|
quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud);
|
|
else
|
|
quot = DIV_ROUND_CLOSEST(port->uartclk * 4, baud);
|
|
|
|
switch (termios->c_cflag & CSIZE) {
|
|
case CS5:
|
|
lcr_h = UART01x_LCRH_WLEN_5;
|
|
break;
|
|
case CS6:
|
|
lcr_h = UART01x_LCRH_WLEN_6;
|
|
break;
|
|
case CS7:
|
|
lcr_h = UART01x_LCRH_WLEN_7;
|
|
break;
|
|
default: // CS8
|
|
lcr_h = UART01x_LCRH_WLEN_8;
|
|
break;
|
|
}
|
|
if (termios->c_cflag & CSTOPB)
|
|
lcr_h |= UART01x_LCRH_STP2;
|
|
if (termios->c_cflag & PARENB) {
|
|
lcr_h |= UART01x_LCRH_PEN;
|
|
if (!(termios->c_cflag & PARODD))
|
|
lcr_h |= UART01x_LCRH_EPS;
|
|
if (termios->c_cflag & CMSPAR)
|
|
lcr_h |= UART011_LCRH_SPS;
|
|
}
|
|
if (uap->fifosize > 1)
|
|
lcr_h |= UART01x_LCRH_FEN;
|
|
|
|
bits = tty_get_frame_size(termios->c_cflag);
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
|
|
/*
|
|
* Update the per-port timeout.
|
|
*/
|
|
uart_update_timeout(port, termios->c_cflag, baud);
|
|
|
|
/*
|
|
* Calculate the approximated time it takes to transmit one character
|
|
* with the given baud rate. We use this as the poll interval when we
|
|
* wait for the tx queue to empty.
|
|
*/
|
|
uap->rs485_tx_drain_interval = (bits * 1000 * 1000) / baud;
|
|
|
|
pl011_setup_status_masks(port, termios);
|
|
|
|
if (UART_ENABLE_MS(port, termios->c_cflag))
|
|
pl011_enable_ms(port);
|
|
|
|
if (port->rs485.flags & SER_RS485_ENABLED)
|
|
termios->c_cflag &= ~CRTSCTS;
|
|
|
|
/* first, disable everything */
|
|
old_cr = pl011_read(uap, REG_CR);
|
|
pl011_write(0, uap, REG_CR);
|
|
|
|
if (termios->c_cflag & CRTSCTS) {
|
|
if (old_cr & UART011_CR_RTS)
|
|
old_cr |= UART011_CR_RTSEN;
|
|
|
|
old_cr |= UART011_CR_CTSEN;
|
|
port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
|
|
} else {
|
|
old_cr &= ~(UART011_CR_CTSEN | UART011_CR_RTSEN);
|
|
port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
|
|
}
|
|
|
|
if (uap->vendor->oversampling) {
|
|
if (baud > port->uartclk / 16)
|
|
old_cr |= ST_UART011_CR_OVSFACT;
|
|
else
|
|
old_cr &= ~ST_UART011_CR_OVSFACT;
|
|
}
|
|
|
|
/*
|
|
* Workaround for the ST Micro oversampling variants to
|
|
* increase the bitrate slightly, by lowering the divisor,
|
|
* to avoid delayed sampling of start bit at high speeds,
|
|
* else we see data corruption.
|
|
*/
|
|
if (uap->vendor->oversampling) {
|
|
if ((baud >= 3000000) && (baud < 3250000) && (quot > 1))
|
|
quot -= 1;
|
|
else if ((baud > 3250000) && (quot > 2))
|
|
quot -= 2;
|
|
}
|
|
/* Set baud rate */
|
|
pl011_write(quot & 0x3f, uap, REG_FBRD);
|
|
pl011_write(quot >> 6, uap, REG_IBRD);
|
|
|
|
/*
|
|
* ----------v----------v----------v----------v-----
|
|
* NOTE: REG_LCRH_TX and REG_LCRH_RX MUST BE WRITTEN AFTER
|
|
* REG_FBRD & REG_IBRD.
|
|
* ----------^----------^----------^----------^-----
|
|
*/
|
|
pl011_write_lcr_h(uap, lcr_h);
|
|
pl011_write(old_cr, uap, REG_CR);
|
|
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
|
|
static void
|
|
sbsa_uart_set_termios(struct uart_port *port, struct ktermios *termios,
|
|
struct ktermios *old)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
unsigned long flags;
|
|
|
|
tty_termios_encode_baud_rate(termios, uap->fixed_baud, uap->fixed_baud);
|
|
|
|
/* The SBSA UART only supports 8n1 without hardware flow control. */
|
|
termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
|
|
termios->c_cflag &= ~(CMSPAR | CRTSCTS);
|
|
termios->c_cflag |= CS8 | CLOCAL;
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
uart_update_timeout(port, CS8, uap->fixed_baud);
|
|
pl011_setup_status_masks(port, termios);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
|
|
static const char *pl011_type(struct uart_port *port)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
return uap->port.type == PORT_AMBA ? uap->type : NULL;
|
|
}
|
|
|
|
/*
|
|
* Release the memory region(s) being used by 'port'
|
|
*/
|
|
static void pl011_release_port(struct uart_port *port)
|
|
{
|
|
release_mem_region(port->mapbase, SZ_4K);
|
|
}
|
|
|
|
/*
|
|
* Request the memory region(s) being used by 'port'
|
|
*/
|
|
static int pl011_request_port(struct uart_port *port)
|
|
{
|
|
return request_mem_region(port->mapbase, SZ_4K, "uart-pl011")
|
|
!= NULL ? 0 : -EBUSY;
|
|
}
|
|
|
|
/*
|
|
* Configure/autoconfigure the port.
|
|
*/
|
|
static void pl011_config_port(struct uart_port *port, int flags)
|
|
{
|
|
if (flags & UART_CONFIG_TYPE) {
|
|
port->type = PORT_AMBA;
|
|
pl011_request_port(port);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* verify the new serial_struct (for TIOCSSERIAL).
|
|
*/
|
|
static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser)
|
|
{
|
|
int ret = 0;
|
|
if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
|
|
ret = -EINVAL;
|
|
if (ser->irq < 0 || ser->irq >= nr_irqs)
|
|
ret = -EINVAL;
|
|
if (ser->baud_base < 9600)
|
|
ret = -EINVAL;
|
|
return ret;
|
|
}
|
|
|
|
static int pl011_rs485_config(struct uart_port *port,
|
|
struct serial_rs485 *rs485)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
/* pick sane settings if the user hasn't */
|
|
if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
|
|
!(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
|
|
rs485->flags |= SER_RS485_RTS_ON_SEND;
|
|
rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
|
|
}
|
|
/* clamp the delays to [0, 100ms] */
|
|
rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
|
|
rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);
|
|
memset(rs485->padding, 0, sizeof(rs485->padding));
|
|
|
|
if (port->rs485.flags & SER_RS485_ENABLED)
|
|
pl011_rs485_tx_stop(uap);
|
|
|
|
/* Set new configuration */
|
|
port->rs485 = *rs485;
|
|
|
|
/* Make sure auto RTS is disabled */
|
|
if (port->rs485.flags & SER_RS485_ENABLED) {
|
|
u32 cr = pl011_read(uap, REG_CR);
|
|
|
|
cr &= ~UART011_CR_RTSEN;
|
|
pl011_write(cr, uap, REG_CR);
|
|
port->status &= ~UPSTAT_AUTORTS;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct uart_ops amba_pl011_pops = {
|
|
.tx_empty = pl011_tx_empty,
|
|
.set_mctrl = pl011_set_mctrl,
|
|
.get_mctrl = pl011_get_mctrl,
|
|
.stop_tx = pl011_stop_tx,
|
|
.start_tx = pl011_start_tx,
|
|
.stop_rx = pl011_stop_rx,
|
|
.enable_ms = pl011_enable_ms,
|
|
.break_ctl = pl011_break_ctl,
|
|
.startup = pl011_startup,
|
|
.shutdown = pl011_shutdown,
|
|
.flush_buffer = pl011_dma_flush_buffer,
|
|
.set_termios = pl011_set_termios,
|
|
.type = pl011_type,
|
|
.release_port = pl011_release_port,
|
|
.request_port = pl011_request_port,
|
|
.config_port = pl011_config_port,
|
|
.verify_port = pl011_verify_port,
|
|
#ifdef CONFIG_CONSOLE_POLL
|
|
.poll_init = pl011_hwinit,
|
|
.poll_get_char = pl011_get_poll_char,
|
|
.poll_put_char = pl011_put_poll_char,
|
|
#endif
|
|
};
|
|
|
|
static void sbsa_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
|
|
{
|
|
}
|
|
|
|
static unsigned int sbsa_uart_get_mctrl(struct uart_port *port)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static const struct uart_ops sbsa_uart_pops = {
|
|
.tx_empty = pl011_tx_empty,
|
|
.set_mctrl = sbsa_uart_set_mctrl,
|
|
.get_mctrl = sbsa_uart_get_mctrl,
|
|
.stop_tx = pl011_stop_tx,
|
|
.start_tx = pl011_start_tx,
|
|
.stop_rx = pl011_stop_rx,
|
|
.startup = sbsa_uart_startup,
|
|
.shutdown = sbsa_uart_shutdown,
|
|
.set_termios = sbsa_uart_set_termios,
|
|
.type = pl011_type,
|
|
.release_port = pl011_release_port,
|
|
.request_port = pl011_request_port,
|
|
.config_port = pl011_config_port,
|
|
.verify_port = pl011_verify_port,
|
|
#ifdef CONFIG_CONSOLE_POLL
|
|
.poll_init = pl011_hwinit,
|
|
.poll_get_char = pl011_get_poll_char,
|
|
.poll_put_char = pl011_put_poll_char,
|
|
#endif
|
|
};
|
|
|
|
static struct uart_amba_port *amba_ports[UART_NR];
|
|
|
|
#ifdef CONFIG_SERIAL_AMBA_PL011_CONSOLE
|
|
|
|
static void pl011_console_putchar(struct uart_port *port, int ch)
|
|
{
|
|
struct uart_amba_port *uap =
|
|
container_of(port, struct uart_amba_port, port);
|
|
|
|
while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
|
|
cpu_relax();
|
|
pl011_write(ch, uap, REG_DR);
|
|
}
|
|
|
|
static void
|
|
pl011_console_write(struct console *co, const char *s, unsigned int count)
|
|
{
|
|
struct uart_amba_port *uap = amba_ports[co->index];
|
|
unsigned int old_cr = 0, new_cr;
|
|
unsigned long flags;
|
|
int locked = 1;
|
|
|
|
clk_enable(uap->clk);
|
|
|
|
local_irq_save(flags);
|
|
if (uap->port.sysrq)
|
|
locked = 0;
|
|
else if (oops_in_progress)
|
|
locked = spin_trylock(&uap->port.lock);
|
|
else
|
|
spin_lock(&uap->port.lock);
|
|
|
|
/*
|
|
* First save the CR then disable the interrupts
|
|
*/
|
|
if (!uap->vendor->always_enabled) {
|
|
old_cr = pl011_read(uap, REG_CR);
|
|
new_cr = old_cr & ~UART011_CR_CTSEN;
|
|
new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
|
|
pl011_write(new_cr, uap, REG_CR);
|
|
}
|
|
|
|
uart_console_write(&uap->port, s, count, pl011_console_putchar);
|
|
|
|
/*
|
|
* Finally, wait for transmitter to become empty and restore the
|
|
* TCR. Allow feature register bits to be inverted to work around
|
|
* errata.
|
|
*/
|
|
while ((pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr)
|
|
& uap->vendor->fr_busy)
|
|
cpu_relax();
|
|
if (!uap->vendor->always_enabled)
|
|
pl011_write(old_cr, uap, REG_CR);
|
|
|
|
if (locked)
|
|
spin_unlock(&uap->port.lock);
|
|
local_irq_restore(flags);
|
|
|
|
clk_disable(uap->clk);
|
|
}
|
|
|
|
static void pl011_console_get_options(struct uart_amba_port *uap, int *baud,
|
|
int *parity, int *bits)
|
|
{
|
|
if (pl011_read(uap, REG_CR) & UART01x_CR_UARTEN) {
|
|
unsigned int lcr_h, ibrd, fbrd;
|
|
|
|
lcr_h = pl011_read(uap, REG_LCRH_TX);
|
|
|
|
*parity = 'n';
|
|
if (lcr_h & UART01x_LCRH_PEN) {
|
|
if (lcr_h & UART01x_LCRH_EPS)
|
|
*parity = 'e';
|
|
else
|
|
*parity = 'o';
|
|
}
|
|
|
|
if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
|
|
*bits = 7;
|
|
else
|
|
*bits = 8;
|
|
|
|
ibrd = pl011_read(uap, REG_IBRD);
|
|
fbrd = pl011_read(uap, REG_FBRD);
|
|
|
|
*baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd);
|
|
|
|
if (uap->vendor->oversampling) {
|
|
if (pl011_read(uap, REG_CR)
|
|
& ST_UART011_CR_OVSFACT)
|
|
*baud *= 2;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int pl011_console_setup(struct console *co, char *options)
|
|
{
|
|
struct uart_amba_port *uap;
|
|
int baud = 38400;
|
|
int bits = 8;
|
|
int parity = 'n';
|
|
int flow = 'n';
|
|
int ret;
|
|
|
|
/*
|
|
* Check whether an invalid uart number has been specified, and
|
|
* if so, search for the first available port that does have
|
|
* console support.
|
|
*/
|
|
if (co->index >= UART_NR)
|
|
co->index = 0;
|
|
uap = amba_ports[co->index];
|
|
if (!uap)
|
|
return -ENODEV;
|
|
|
|
/* Allow pins to be muxed in and configured */
|
|
pinctrl_pm_select_default_state(uap->port.dev);
|
|
|
|
ret = clk_prepare(uap->clk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (dev_get_platdata(uap->port.dev)) {
|
|
struct amba_pl011_data *plat;
|
|
|
|
plat = dev_get_platdata(uap->port.dev);
|
|
if (plat->init)
|
|
plat->init();
|
|
}
|
|
|
|
uap->port.uartclk = clk_get_rate(uap->clk);
|
|
|
|
if (uap->vendor->fixed_options) {
|
|
baud = uap->fixed_baud;
|
|
} else {
|
|
if (options)
|
|
uart_parse_options(options,
|
|
&baud, &parity, &bits, &flow);
|
|
else
|
|
pl011_console_get_options(uap, &baud, &parity, &bits);
|
|
}
|
|
|
|
return uart_set_options(&uap->port, co, baud, parity, bits, flow);
|
|
}
|
|
|
|
/**
|
|
* pl011_console_match - non-standard console matching
|
|
* @co: registering console
|
|
* @name: name from console command line
|
|
* @idx: index from console command line
|
|
* @options: ptr to option string from console command line
|
|
*
|
|
* Only attempts to match console command lines of the form:
|
|
* console=pl011,mmio|mmio32,<addr>[,<options>]
|
|
* console=pl011,0x<addr>[,<options>]
|
|
* This form is used to register an initial earlycon boot console and
|
|
* replace it with the amba_console at pl011 driver init.
|
|
*
|
|
* Performs console setup for a match (as required by interface)
|
|
* If no <options> are specified, then assume the h/w is already setup.
|
|
*
|
|
* Returns 0 if console matches; otherwise non-zero to use default matching
|
|
*/
|
|
static int pl011_console_match(struct console *co, char *name, int idx,
|
|
char *options)
|
|
{
|
|
unsigned char iotype;
|
|
resource_size_t addr;
|
|
int i;
|
|
|
|
/*
|
|
* Systems affected by the Qualcomm Technologies QDF2400 E44 erratum
|
|
* have a distinct console name, so make sure we check for that.
|
|
* The actual implementation of the erratum occurs in the probe
|
|
* function.
|
|
*/
|
|
if ((strcmp(name, "qdf2400_e44") != 0) && (strcmp(name, "pl011") != 0))
|
|
return -ENODEV;
|
|
|
|
if (uart_parse_earlycon(options, &iotype, &addr, &options))
|
|
return -ENODEV;
|
|
|
|
if (iotype != UPIO_MEM && iotype != UPIO_MEM32)
|
|
return -ENODEV;
|
|
|
|
/* try to match the port specified on the command line */
|
|
for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
|
|
struct uart_port *port;
|
|
|
|
if (!amba_ports[i])
|
|
continue;
|
|
|
|
port = &amba_ports[i]->port;
|
|
|
|
if (port->mapbase != addr)
|
|
continue;
|
|
|
|
co->index = i;
|
|
port->cons = co;
|
|
return pl011_console_setup(co, options);
|
|
}
|
|
|
|
return -ENODEV;
|
|
}
|
|
|
|
static struct uart_driver amba_reg;
|
|
static struct console amba_console = {
|
|
.name = "ttyAMA",
|
|
.write = pl011_console_write,
|
|
.device = uart_console_device,
|
|
.setup = pl011_console_setup,
|
|
.match = pl011_console_match,
|
|
.flags = CON_PRINTBUFFER | CON_ANYTIME,
|
|
.index = -1,
|
|
.data = &amba_reg,
|
|
};
|
|
|
|
#define AMBA_CONSOLE (&amba_console)
|
|
|
|
static void qdf2400_e44_putc(struct uart_port *port, int c)
|
|
{
|
|
while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
|
|
cpu_relax();
|
|
writel(c, port->membase + UART01x_DR);
|
|
while (!(readl(port->membase + UART01x_FR) & UART011_FR_TXFE))
|
|
cpu_relax();
|
|
}
|
|
|
|
static void qdf2400_e44_early_write(struct console *con, const char *s, unsigned n)
|
|
{
|
|
struct earlycon_device *dev = con->data;
|
|
|
|
uart_console_write(&dev->port, s, n, qdf2400_e44_putc);
|
|
}
|
|
|
|
static void pl011_putc(struct uart_port *port, int c)
|
|
{
|
|
while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
|
|
cpu_relax();
|
|
if (port->iotype == UPIO_MEM32)
|
|
writel(c, port->membase + UART01x_DR);
|
|
else
|
|
writeb(c, port->membase + UART01x_DR);
|
|
while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
|
|
cpu_relax();
|
|
}
|
|
|
|
static void pl011_early_write(struct console *con, const char *s, unsigned n)
|
|
{
|
|
struct earlycon_device *dev = con->data;
|
|
|
|
uart_console_write(&dev->port, s, n, pl011_putc);
|
|
}
|
|
|
|
#ifdef CONFIG_CONSOLE_POLL
|
|
static int pl011_getc(struct uart_port *port)
|
|
{
|
|
if (readl(port->membase + UART01x_FR) & UART01x_FR_RXFE)
|
|
return NO_POLL_CHAR;
|
|
|
|
if (port->iotype == UPIO_MEM32)
|
|
return readl(port->membase + UART01x_DR);
|
|
else
|
|
return readb(port->membase + UART01x_DR);
|
|
}
|
|
|
|
static int pl011_early_read(struct console *con, char *s, unsigned int n)
|
|
{
|
|
struct earlycon_device *dev = con->data;
|
|
int ch, num_read = 0;
|
|
|
|
while (num_read < n) {
|
|
ch = pl011_getc(&dev->port);
|
|
if (ch == NO_POLL_CHAR)
|
|
break;
|
|
|
|
s[num_read++] = ch;
|
|
}
|
|
|
|
return num_read;
|
|
}
|
|
#else
|
|
#define pl011_early_read NULL
|
|
#endif
|
|
|
|
/*
|
|
* On non-ACPI systems, earlycon is enabled by specifying
|
|
* "earlycon=pl011,<address>" on the kernel command line.
|
|
*
|
|
* On ACPI ARM64 systems, an "early" console is enabled via the SPCR table,
|
|
* by specifying only "earlycon" on the command line. Because it requires
|
|
* SPCR, the console starts after ACPI is parsed, which is later than a
|
|
* traditional early console.
|
|
*
|
|
* To get the traditional early console that starts before ACPI is parsed,
|
|
* specify the full "earlycon=pl011,<address>" option.
|
|
*/
|
|
static int __init pl011_early_console_setup(struct earlycon_device *device,
|
|
const char *opt)
|
|
{
|
|
if (!device->port.membase)
|
|
return -ENODEV;
|
|
|
|
device->con->write = pl011_early_write;
|
|
device->con->read = pl011_early_read;
|
|
|
|
return 0;
|
|
}
|
|
OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup);
|
|
OF_EARLYCON_DECLARE(pl011, "arm,sbsa-uart", pl011_early_console_setup);
|
|
|
|
/*
|
|
* On Qualcomm Datacenter Technologies QDF2400 SOCs affected by
|
|
* Erratum 44, traditional earlycon can be enabled by specifying
|
|
* "earlycon=qdf2400_e44,<address>". Any options are ignored.
|
|
*
|
|
* Alternatively, you can just specify "earlycon", and the early console
|
|
* will be enabled with the information from the SPCR table. In this
|
|
* case, the SPCR code will detect the need for the E44 work-around,
|
|
* and set the console name to "qdf2400_e44".
|
|
*/
|
|
static int __init
|
|
qdf2400_e44_early_console_setup(struct earlycon_device *device,
|
|
const char *opt)
|
|
{
|
|
if (!device->port.membase)
|
|
return -ENODEV;
|
|
|
|
device->con->write = qdf2400_e44_early_write;
|
|
return 0;
|
|
}
|
|
EARLYCON_DECLARE(qdf2400_e44, qdf2400_e44_early_console_setup);
|
|
|
|
#else
|
|
#define AMBA_CONSOLE NULL
|
|
#endif
|
|
|
|
static struct uart_driver amba_reg = {
|
|
.owner = THIS_MODULE,
|
|
.driver_name = "ttyAMA",
|
|
.dev_name = "ttyAMA",
|
|
.major = SERIAL_AMBA_MAJOR,
|
|
.minor = SERIAL_AMBA_MINOR,
|
|
.nr = UART_NR,
|
|
.cons = AMBA_CONSOLE,
|
|
};
|
|
|
|
static int pl011_probe_dt_alias(int index, struct device *dev)
|
|
{
|
|
struct device_node *np;
|
|
static bool seen_dev_with_alias = false;
|
|
static bool seen_dev_without_alias = false;
|
|
int ret = index;
|
|
|
|
if (!IS_ENABLED(CONFIG_OF))
|
|
return ret;
|
|
|
|
np = dev->of_node;
|
|
if (!np)
|
|
return ret;
|
|
|
|
ret = of_alias_get_id(np, "serial");
|
|
if (ret < 0) {
|
|
seen_dev_without_alias = true;
|
|
ret = index;
|
|
} else {
|
|
seen_dev_with_alias = true;
|
|
if (ret >= ARRAY_SIZE(amba_ports) || amba_ports[ret] != NULL) {
|
|
dev_warn(dev, "requested serial port %d not available.\n", ret);
|
|
ret = index;
|
|
}
|
|
}
|
|
|
|
if (seen_dev_with_alias && seen_dev_without_alias)
|
|
dev_warn(dev, "aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.\n");
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* unregisters the driver also if no more ports are left */
|
|
static void pl011_unregister_port(struct uart_amba_port *uap)
|
|
{
|
|
int i;
|
|
bool busy = false;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
|
|
if (amba_ports[i] == uap)
|
|
amba_ports[i] = NULL;
|
|
else if (amba_ports[i])
|
|
busy = true;
|
|
}
|
|
pl011_dma_remove(uap);
|
|
if (!busy)
|
|
uart_unregister_driver(&amba_reg);
|
|
}
|
|
|
|
static int pl011_find_free_port(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
|
|
if (amba_ports[i] == NULL)
|
|
return i;
|
|
|
|
return -EBUSY;
|
|
}
|
|
|
|
static int pl011_get_rs485_mode(struct uart_amba_port *uap)
|
|
{
|
|
struct uart_port *port = &uap->port;
|
|
struct serial_rs485 *rs485 = &port->rs485;
|
|
int ret;
|
|
|
|
ret = uart_get_rs485_mode(port);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* clamp the delays to [0, 100ms] */
|
|
rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
|
|
rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
|
|
struct resource *mmiobase, int index)
|
|
{
|
|
void __iomem *base;
|
|
int ret;
|
|
|
|
base = devm_ioremap_resource(dev, mmiobase);
|
|
if (IS_ERR(base))
|
|
return PTR_ERR(base);
|
|
|
|
index = pl011_probe_dt_alias(index, dev);
|
|
|
|
uap->old_cr = 0;
|
|
uap->port.dev = dev;
|
|
uap->port.mapbase = mmiobase->start;
|
|
uap->port.membase = base;
|
|
uap->port.fifosize = uap->fifosize;
|
|
uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL011_CONSOLE);
|
|
uap->port.flags = UPF_BOOT_AUTOCONF;
|
|
uap->port.line = index;
|
|
|
|
ret = pl011_get_rs485_mode(uap);
|
|
if (ret)
|
|
return ret;
|
|
|
|
amba_ports[index] = uap;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pl011_register_port(struct uart_amba_port *uap)
|
|
{
|
|
int ret, i;
|
|
|
|
/* Ensure interrupts from this UART are masked and cleared */
|
|
pl011_write(0, uap, REG_IMSC);
|
|
pl011_write(0xffff, uap, REG_ICR);
|
|
|
|
if (!amba_reg.state) {
|
|
ret = uart_register_driver(&amba_reg);
|
|
if (ret < 0) {
|
|
dev_err(uap->port.dev,
|
|
"Failed to register AMBA-PL011 driver\n");
|
|
for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
|
|
if (amba_ports[i] == uap)
|
|
amba_ports[i] = NULL;
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
ret = uart_add_one_port(&amba_reg, &uap->port);
|
|
if (ret)
|
|
pl011_unregister_port(uap);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
|
|
{
|
|
struct uart_amba_port *uap;
|
|
struct vendor_data *vendor = id->data;
|
|
int portnr, ret;
|
|
|
|
portnr = pl011_find_free_port();
|
|
if (portnr < 0)
|
|
return portnr;
|
|
|
|
uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
|
|
GFP_KERNEL);
|
|
if (!uap)
|
|
return -ENOMEM;
|
|
|
|
uap->clk = devm_clk_get(&dev->dev, NULL);
|
|
if (IS_ERR(uap->clk))
|
|
return PTR_ERR(uap->clk);
|
|
|
|
uap->reg_offset = vendor->reg_offset;
|
|
uap->vendor = vendor;
|
|
uap->fifosize = vendor->get_fifosize(dev);
|
|
uap->port.iotype = vendor->access_32b ? UPIO_MEM32 : UPIO_MEM;
|
|
uap->port.irq = dev->irq[0];
|
|
uap->port.ops = &amba_pl011_pops;
|
|
uap->port.rs485_config = pl011_rs485_config;
|
|
snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
|
|
|
|
ret = pl011_setup_port(&dev->dev, uap, &dev->res, portnr);
|
|
if (ret)
|
|
return ret;
|
|
|
|
amba_set_drvdata(dev, uap);
|
|
|
|
return pl011_register_port(uap);
|
|
}
|
|
|
|
static void pl011_remove(struct amba_device *dev)
|
|
{
|
|
struct uart_amba_port *uap = amba_get_drvdata(dev);
|
|
|
|
uart_remove_one_port(&amba_reg, &uap->port);
|
|
pl011_unregister_port(uap);
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int pl011_suspend(struct device *dev)
|
|
{
|
|
struct uart_amba_port *uap = dev_get_drvdata(dev);
|
|
|
|
if (!uap)
|
|
return -EINVAL;
|
|
|
|
return uart_suspend_port(&amba_reg, &uap->port);
|
|
}
|
|
|
|
static int pl011_resume(struct device *dev)
|
|
{
|
|
struct uart_amba_port *uap = dev_get_drvdata(dev);
|
|
|
|
if (!uap)
|
|
return -EINVAL;
|
|
|
|
return uart_resume_port(&amba_reg, &uap->port);
|
|
}
|
|
#endif
|
|
|
|
static SIMPLE_DEV_PM_OPS(pl011_dev_pm_ops, pl011_suspend, pl011_resume);
|
|
|
|
static int sbsa_uart_probe(struct platform_device *pdev)
|
|
{
|
|
struct uart_amba_port *uap;
|
|
struct resource *r;
|
|
int portnr, ret;
|
|
int baudrate;
|
|
|
|
/*
|
|
* Check the mandatory baud rate parameter in the DT node early
|
|
* so that we can easily exit with the error.
|
|
*/
|
|
if (pdev->dev.of_node) {
|
|
struct device_node *np = pdev->dev.of_node;
|
|
|
|
ret = of_property_read_u32(np, "current-speed", &baudrate);
|
|
if (ret)
|
|
return ret;
|
|
} else {
|
|
baudrate = 115200;
|
|
}
|
|
|
|
portnr = pl011_find_free_port();
|
|
if (portnr < 0)
|
|
return portnr;
|
|
|
|
uap = devm_kzalloc(&pdev->dev, sizeof(struct uart_amba_port),
|
|
GFP_KERNEL);
|
|
if (!uap)
|
|
return -ENOMEM;
|
|
|
|
ret = platform_get_irq(pdev, 0);
|
|
if (ret < 0)
|
|
return ret;
|
|
uap->port.irq = ret;
|
|
|
|
#ifdef CONFIG_ACPI_SPCR_TABLE
|
|
if (qdf2400_e44_present) {
|
|
dev_info(&pdev->dev, "working around QDF2400 SoC erratum 44\n");
|
|
uap->vendor = &vendor_qdt_qdf2400_e44;
|
|
} else
|
|
#endif
|
|
uap->vendor = &vendor_sbsa;
|
|
|
|
uap->reg_offset = uap->vendor->reg_offset;
|
|
uap->fifosize = 32;
|
|
uap->port.iotype = uap->vendor->access_32b ? UPIO_MEM32 : UPIO_MEM;
|
|
uap->port.ops = &sbsa_uart_pops;
|
|
uap->fixed_baud = baudrate;
|
|
|
|
snprintf(uap->type, sizeof(uap->type), "SBSA");
|
|
|
|
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
|
|
ret = pl011_setup_port(&pdev->dev, uap, r, portnr);
|
|
if (ret)
|
|
return ret;
|
|
|
|
platform_set_drvdata(pdev, uap);
|
|
|
|
return pl011_register_port(uap);
|
|
}
|
|
|
|
static int sbsa_uart_remove(struct platform_device *pdev)
|
|
{
|
|
struct uart_amba_port *uap = platform_get_drvdata(pdev);
|
|
|
|
uart_remove_one_port(&amba_reg, &uap->port);
|
|
pl011_unregister_port(uap);
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id sbsa_uart_of_match[] = {
|
|
{ .compatible = "arm,sbsa-uart", },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, sbsa_uart_of_match);
|
|
|
|
static const struct acpi_device_id __maybe_unused sbsa_uart_acpi_match[] = {
|
|
{ "ARMH0011", 0 },
|
|
{ "ARMHB000", 0 },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(acpi, sbsa_uart_acpi_match);
|
|
|
|
static struct platform_driver arm_sbsa_uart_platform_driver = {
|
|
.probe = sbsa_uart_probe,
|
|
.remove = sbsa_uart_remove,
|
|
.driver = {
|
|
.name = "sbsa-uart",
|
|
.pm = &pl011_dev_pm_ops,
|
|
.of_match_table = of_match_ptr(sbsa_uart_of_match),
|
|
.acpi_match_table = ACPI_PTR(sbsa_uart_acpi_match),
|
|
.suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011),
|
|
},
|
|
};
|
|
|
|
static const struct amba_id pl011_ids[] = {
|
|
{
|
|
.id = 0x00041011,
|
|
.mask = 0x000fffff,
|
|
.data = &vendor_arm,
|
|
},
|
|
{
|
|
.id = 0x00380802,
|
|
.mask = 0x00ffffff,
|
|
.data = &vendor_st,
|
|
},
|
|
{
|
|
.id = AMBA_LINUX_ID(0x00, 0x1, 0xffe),
|
|
.mask = 0x00ffffff,
|
|
.data = &vendor_zte,
|
|
},
|
|
{ 0, 0 },
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(amba, pl011_ids);
|
|
|
|
static struct amba_driver pl011_driver = {
|
|
.drv = {
|
|
.name = "uart-pl011",
|
|
.pm = &pl011_dev_pm_ops,
|
|
.suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011),
|
|
},
|
|
.id_table = pl011_ids,
|
|
.probe = pl011_probe,
|
|
.remove = pl011_remove,
|
|
};
|
|
|
|
static int __init pl011_init(void)
|
|
{
|
|
printk(KERN_INFO "Serial: AMBA PL011 UART driver\n");
|
|
|
|
if (platform_driver_register(&arm_sbsa_uart_platform_driver))
|
|
pr_warn("could not register SBSA UART platform driver\n");
|
|
return amba_driver_register(&pl011_driver);
|
|
}
|
|
|
|
static void __exit pl011_exit(void)
|
|
{
|
|
platform_driver_unregister(&arm_sbsa_uart_platform_driver);
|
|
amba_driver_unregister(&pl011_driver);
|
|
}
|
|
|
|
/*
|
|
* While this can be a module, if builtin it's most likely the console
|
|
* So let's leave module_exit but move module_init to an earlier place
|
|
*/
|
|
arch_initcall(pl011_init);
|
|
module_exit(pl011_exit);
|
|
|
|
MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
|
|
MODULE_DESCRIPTION("ARM AMBA serial port driver");
|
|
MODULE_LICENSE("GPL");
|