164 строки
4.1 KiB
C
164 строки
4.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Renesas Emma Mobile 8250 driver
|
|
*
|
|
* Copyright (C) 2012 Magnus Damm
|
|
*/
|
|
|
|
#include <linux/device.h>
|
|
#include <linux/io.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mod_devicetable.h>
|
|
#include <linux/serial_8250.h>
|
|
#include <linux/serial_reg.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/clk.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include "8250.h"
|
|
|
|
#define UART_DLL_EM 9
|
|
#define UART_DLM_EM 10
|
|
|
|
struct serial8250_em_priv {
|
|
struct clk *sclk;
|
|
int line;
|
|
};
|
|
|
|
static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
|
|
{
|
|
switch (offset) {
|
|
case UART_TX: /* TX @ 0x00 */
|
|
writeb(value, p->membase);
|
|
break;
|
|
case UART_FCR: /* FCR @ 0x0c (+1) */
|
|
case UART_LCR: /* LCR @ 0x10 (+1) */
|
|
case UART_MCR: /* MCR @ 0x14 (+1) */
|
|
case UART_SCR: /* SCR @ 0x20 (+1) */
|
|
writel(value, p->membase + ((offset + 1) << 2));
|
|
break;
|
|
case UART_IER: /* IER @ 0x04 */
|
|
value &= 0x0f; /* only 4 valid bits - not Xscale */
|
|
fallthrough;
|
|
case UART_DLL_EM: /* DLL @ 0x24 (+9) */
|
|
case UART_DLM_EM: /* DLM @ 0x28 (+9) */
|
|
writel(value, p->membase + (offset << 2));
|
|
}
|
|
}
|
|
|
|
static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
|
|
{
|
|
switch (offset) {
|
|
case UART_RX: /* RX @ 0x00 */
|
|
return readb(p->membase);
|
|
case UART_MCR: /* MCR @ 0x14 (+1) */
|
|
case UART_LSR: /* LSR @ 0x18 (+1) */
|
|
case UART_MSR: /* MSR @ 0x1c (+1) */
|
|
case UART_SCR: /* SCR @ 0x20 (+1) */
|
|
return readl(p->membase + ((offset + 1) << 2));
|
|
case UART_IER: /* IER @ 0x04 */
|
|
case UART_IIR: /* IIR @ 0x08 */
|
|
case UART_DLL_EM: /* DLL @ 0x24 (+9) */
|
|
case UART_DLM_EM: /* DLM @ 0x28 (+9) */
|
|
return readl(p->membase + (offset << 2));
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
|
|
{
|
|
return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;
|
|
}
|
|
|
|
static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
|
|
{
|
|
serial_out(up, UART_DLL_EM, value & 0xff);
|
|
serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
|
|
}
|
|
|
|
static int serial8250_em_probe(struct platform_device *pdev)
|
|
{
|
|
struct serial8250_em_priv *priv;
|
|
struct uart_8250_port up;
|
|
struct resource *regs;
|
|
int irq, ret;
|
|
|
|
irq = platform_get_irq(pdev, 0);
|
|
if (irq < 0)
|
|
return irq;
|
|
|
|
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (!regs) {
|
|
dev_err(&pdev->dev, "missing registers\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
|
|
if (!priv)
|
|
return -ENOMEM;
|
|
|
|
priv->sclk = devm_clk_get(&pdev->dev, "sclk");
|
|
if (IS_ERR(priv->sclk)) {
|
|
dev_err(&pdev->dev, "unable to get clock\n");
|
|
return PTR_ERR(priv->sclk);
|
|
}
|
|
|
|
memset(&up, 0, sizeof(up));
|
|
up.port.mapbase = regs->start;
|
|
up.port.irq = irq;
|
|
up.port.type = PORT_UNKNOWN;
|
|
up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
|
|
up.port.dev = &pdev->dev;
|
|
up.port.private_data = priv;
|
|
|
|
clk_prepare_enable(priv->sclk);
|
|
up.port.uartclk = clk_get_rate(priv->sclk);
|
|
|
|
up.port.iotype = UPIO_MEM32;
|
|
up.port.serial_in = serial8250_em_serial_in;
|
|
up.port.serial_out = serial8250_em_serial_out;
|
|
up.dl_read = serial8250_em_serial_dl_read;
|
|
up.dl_write = serial8250_em_serial_dl_write;
|
|
|
|
ret = serial8250_register_8250_port(&up);
|
|
if (ret < 0) {
|
|
dev_err(&pdev->dev, "unable to register 8250 port\n");
|
|
clk_disable_unprepare(priv->sclk);
|
|
return ret;
|
|
}
|
|
|
|
priv->line = ret;
|
|
platform_set_drvdata(pdev, priv);
|
|
return 0;
|
|
}
|
|
|
|
static int serial8250_em_remove(struct platform_device *pdev)
|
|
{
|
|
struct serial8250_em_priv *priv = platform_get_drvdata(pdev);
|
|
|
|
serial8250_unregister_port(priv->line);
|
|
clk_disable_unprepare(priv->sclk);
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id serial8250_em_dt_ids[] = {
|
|
{ .compatible = "renesas,em-uart", },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, serial8250_em_dt_ids);
|
|
|
|
static struct platform_driver serial8250_em_platform_driver = {
|
|
.driver = {
|
|
.name = "serial8250-em",
|
|
.of_match_table = serial8250_em_dt_ids,
|
|
},
|
|
.probe = serial8250_em_probe,
|
|
.remove = serial8250_em_remove,
|
|
};
|
|
|
|
module_platform_driver(serial8250_em_platform_driver);
|
|
|
|
MODULE_AUTHOR("Magnus Damm");
|
|
MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver");
|
|
MODULE_LICENSE("GPL v2");
|