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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/drivers/tty/serial/msm_serial.c

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38 KiB
C
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/*
* Driver for msm7k serial device and console
*
* Copyright (C) 2007 Google, Inc.
* Author: Robert Love <rlove@google.com>
* Copyright (c) 2011, Code Aurora Forum. All rights reserved.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
# define SUPPORT_SYSRQ
#endif
#include <linux/atomic.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/hrtimer.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include "msm_serial.h"
#define UARTDM_BURST_SIZE 16 /* in bytes */
#define UARTDM_TX_AIGN(x) ((x) & ~0x3) /* valid for > 1p3 */
#define UARTDM_TX_MAX 256 /* in bytes, valid for <= 1p3 */
#define UARTDM_RX_SIZE (UART_XMIT_SIZE / 4)
enum {
UARTDM_1P1 = 1,
UARTDM_1P2,
UARTDM_1P3,
UARTDM_1P4,
};
struct msm_dma {
struct dma_chan *chan;
enum dma_data_direction dir;
dma_addr_t phys;
unsigned char *virt;
dma_cookie_t cookie;
u32 enable_bit;
unsigned int count;
struct dma_async_tx_descriptor *desc;
};
struct msm_port {
struct uart_port uart;
char name[16];
struct clk *clk;
struct clk *pclk;
unsigned int imr;
int is_uartdm;
unsigned int old_snap_state;
bool break_detected;
struct msm_dma tx_dma;
struct msm_dma rx_dma;
};
static void msm_handle_tx(struct uart_port *port);
static void msm_start_rx_dma(struct msm_port *msm_port);
void msm_stop_dma(struct uart_port *port, struct msm_dma *dma)
{
struct device *dev = port->dev;
unsigned int mapped;
u32 val;
mapped = dma->count;
dma->count = 0;
dmaengine_terminate_all(dma->chan);
/*
* DMA Stall happens if enqueue and flush command happens concurrently.
* For example before changing the baud rate/protocol configuration and
* sending flush command to ADM, disable the channel of UARTDM.
* Note: should not reset the receiver here immediately as it is not
* suggested to do disable/reset or reset/disable at the same time.
*/
val = msm_read(port, UARTDM_DMEN);
val &= ~dma->enable_bit;
msm_write(port, val, UARTDM_DMEN);
if (mapped)
dma_unmap_single(dev, dma->phys, mapped, dma->dir);
}
static void msm_release_dma(struct msm_port *msm_port)
{
struct msm_dma *dma;
dma = &msm_port->tx_dma;
if (dma->chan) {
msm_stop_dma(&msm_port->uart, dma);
dma_release_channel(dma->chan);
}
memset(dma, 0, sizeof(*dma));
dma = &msm_port->rx_dma;
if (dma->chan) {
msm_stop_dma(&msm_port->uart, dma);
dma_release_channel(dma->chan);
kfree(dma->virt);
}
memset(dma, 0, sizeof(*dma));
}
static void msm_request_tx_dma(struct msm_port *msm_port, resource_size_t base)
{
struct device *dev = msm_port->uart.dev;
struct dma_slave_config conf;
struct msm_dma *dma;
u32 crci = 0;
int ret;
dma = &msm_port->tx_dma;
/* allocate DMA resources, if available */
dma->chan = dma_request_slave_channel_reason(dev, "tx");
if (IS_ERR(dma->chan))
goto no_tx;
of_property_read_u32(dev->of_node, "qcom,tx-crci", &crci);
memset(&conf, 0, sizeof(conf));
conf.direction = DMA_MEM_TO_DEV;
conf.device_fc = true;
conf.dst_addr = base + UARTDM_TF;
conf.dst_maxburst = UARTDM_BURST_SIZE;
conf.slave_id = crci;
ret = dmaengine_slave_config(dma->chan, &conf);
if (ret)
goto rel_tx;
dma->dir = DMA_TO_DEVICE;
if (msm_port->is_uartdm < UARTDM_1P4)
dma->enable_bit = UARTDM_DMEN_TX_DM_ENABLE;
else
dma->enable_bit = UARTDM_DMEN_TX_BAM_ENABLE;
return;
rel_tx:
dma_release_channel(dma->chan);
no_tx:
memset(dma, 0, sizeof(*dma));
}
static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base)
{
struct device *dev = msm_port->uart.dev;
struct dma_slave_config conf;
struct msm_dma *dma;
u32 crci = 0;
int ret;
dma = &msm_port->rx_dma;
/* allocate DMA resources, if available */
dma->chan = dma_request_slave_channel_reason(dev, "rx");
if (IS_ERR(dma->chan))
goto no_rx;
of_property_read_u32(dev->of_node, "qcom,rx-crci", &crci);
dma->virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL);
if (!dma->virt)
goto rel_rx;
memset(&conf, 0, sizeof(conf));
conf.direction = DMA_DEV_TO_MEM;
conf.device_fc = true;
conf.src_addr = base + UARTDM_RF;
conf.src_maxburst = UARTDM_BURST_SIZE;
conf.slave_id = crci;
ret = dmaengine_slave_config(dma->chan, &conf);
if (ret)
goto err;
dma->dir = DMA_FROM_DEVICE;
if (msm_port->is_uartdm < UARTDM_1P4)
dma->enable_bit = UARTDM_DMEN_RX_DM_ENABLE;
else
dma->enable_bit = UARTDM_DMEN_RX_BAM_ENABLE;
return;
err:
kfree(dma->virt);
rel_rx:
dma_release_channel(dma->chan);
no_rx:
memset(dma, 0, sizeof(*dma));
}
static inline void msm_wait_for_xmitr(struct uart_port *port)
{
while (!(msm_read(port, UART_SR) & UART_SR_TX_EMPTY)) {
if (msm_read(port, UART_ISR) & UART_ISR_TX_READY)
break;
udelay(1);
}
msm_write(port, UART_CR_CMD_RESET_TX_READY, UART_CR);
}
static void msm_stop_tx(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
msm_port->imr &= ~UART_IMR_TXLEV;
msm_write(port, msm_port->imr, UART_IMR);
}
static void msm_start_tx(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
struct msm_dma *dma = &msm_port->tx_dma;
/* Already started in DMA mode */
if (dma->count)
return;
msm_port->imr |= UART_IMR_TXLEV;
msm_write(port, msm_port->imr, UART_IMR);
}
static void msm_reset_dm_count(struct uart_port *port, int count)
{
msm_wait_for_xmitr(port);
msm_write(port, count, UARTDM_NCF_TX);
msm_read(port, UARTDM_NCF_TX);
}
static void msm_complete_tx_dma(void *args)
{
struct msm_port *msm_port = args;
struct uart_port *port = &msm_port->uart;
struct circ_buf *xmit = &port->state->xmit;
struct msm_dma *dma = &msm_port->tx_dma;
struct dma_tx_state state;
enum dma_status status;
unsigned long flags;
unsigned int count;
u32 val;
spin_lock_irqsave(&port->lock, flags);
/* Already stopped */
if (!dma->count)
goto done;
status = dmaengine_tx_status(dma->chan, dma->cookie, &state);
dma_unmap_single(port->dev, dma->phys, dma->count, dma->dir);
val = msm_read(port, UARTDM_DMEN);
val &= ~dma->enable_bit;
msm_write(port, val, UARTDM_DMEN);
if (msm_port->is_uartdm > UARTDM_1P3) {
msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
msm_write(port, UART_CR_TX_ENABLE, UART_CR);
}
count = dma->count - state.residue;
port->icount.tx += count;
dma->count = 0;
xmit->tail += count;
xmit->tail &= UART_XMIT_SIZE - 1;
/* Restore "Tx FIFO below watermark" interrupt */
msm_port->imr |= UART_IMR_TXLEV;
msm_write(port, msm_port->imr, UART_IMR);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
msm_handle_tx(port);
done:
spin_unlock_irqrestore(&port->lock, flags);
}
static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count)
{
struct circ_buf *xmit = &msm_port->uart.state->xmit;
struct uart_port *port = &msm_port->uart;
struct msm_dma *dma = &msm_port->tx_dma;
void *cpu_addr;
int ret;
u32 val;
cpu_addr = &xmit->buf[xmit->tail];
dma->phys = dma_map_single(port->dev, cpu_addr, count, dma->dir);
ret = dma_mapping_error(port->dev, dma->phys);
if (ret)
return ret;
dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys,
count, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT |
DMA_PREP_FENCE);
if (!dma->desc) {
ret = -EIO;
goto unmap;
}
dma->desc->callback = msm_complete_tx_dma;
dma->desc->callback_param = msm_port;
dma->cookie = dmaengine_submit(dma->desc);
ret = dma_submit_error(dma->cookie);
if (ret)
goto unmap;
/*
* Using DMA complete for Tx FIFO reload, no need for
* "Tx FIFO below watermark" one, disable it
*/
msm_port->imr &= ~UART_IMR_TXLEV;
msm_write(port, msm_port->imr, UART_IMR);
dma->count = count;
val = msm_read(port, UARTDM_DMEN);
val |= dma->enable_bit;
if (msm_port->is_uartdm < UARTDM_1P4)
msm_write(port, val, UARTDM_DMEN);
msm_reset_dm_count(port, count);
if (msm_port->is_uartdm > UARTDM_1P3)
msm_write(port, val, UARTDM_DMEN);
dma_async_issue_pending(dma->chan);
return 0;
unmap:
dma_unmap_single(port->dev, dma->phys, count, dma->dir);
return ret;
}
static void msm_complete_rx_dma(void *args)
{
struct msm_port *msm_port = args;
struct uart_port *port = &msm_port->uart;
struct tty_port *tport = &port->state->port;
struct msm_dma *dma = &msm_port->rx_dma;
int count = 0, i, sysrq;
unsigned long flags;
u32 val;
spin_lock_irqsave(&port->lock, flags);
/* Already stopped */
if (!dma->count)
goto done;
val = msm_read(port, UARTDM_DMEN);
val &= ~dma->enable_bit;
msm_write(port, val, UARTDM_DMEN);
/* Restore interrupts */
msm_port->imr |= UART_IMR_RXLEV | UART_IMR_RXSTALE;
msm_write(port, msm_port->imr, UART_IMR);
if (msm_read(port, UART_SR) & UART_SR_OVERRUN) {
port->icount.overrun++;
tty_insert_flip_char(tport, 0, TTY_OVERRUN);
msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
}
count = msm_read(port, UARTDM_RX_TOTAL_SNAP);
port->icount.rx += count;
dma->count = 0;
dma_unmap_single(port->dev, dma->phys, UARTDM_RX_SIZE, dma->dir);
for (i = 0; i < count; i++) {
char flag = TTY_NORMAL;
if (msm_port->break_detected && dma->virt[i] == 0) {
port->icount.brk++;
flag = TTY_BREAK;
msm_port->break_detected = false;
if (uart_handle_break(port))
continue;
}
if (!(port->read_status_mask & UART_SR_RX_BREAK))
flag = TTY_NORMAL;
spin_unlock_irqrestore(&port->lock, flags);
sysrq = uart_handle_sysrq_char(port, dma->virt[i]);
spin_lock_irqsave(&port->lock, flags);
if (!sysrq)
tty_insert_flip_char(tport, dma->virt[i], flag);
}
msm_start_rx_dma(msm_port);
done:
spin_unlock_irqrestore(&port->lock, flags);
if (count)
tty_flip_buffer_push(tport);
}
static void msm_start_rx_dma(struct msm_port *msm_port)
{
struct msm_dma *dma = &msm_port->rx_dma;
struct uart_port *uart = &msm_port->uart;
u32 val;
int ret;
if (!dma->chan)
return;
dma->phys = dma_map_single(uart->dev, dma->virt,
UARTDM_RX_SIZE, dma->dir);
ret = dma_mapping_error(uart->dev, dma->phys);
if (ret)
return;
dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys,
UARTDM_RX_SIZE, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT);
if (!dma->desc)
goto unmap;
dma->desc->callback = msm_complete_rx_dma;
dma->desc->callback_param = msm_port;
dma->cookie = dmaengine_submit(dma->desc);
ret = dma_submit_error(dma->cookie);
if (ret)
goto unmap;
/*
* Using DMA for FIFO off-load, no need for "Rx FIFO over
* watermark" or "stale" interrupts, disable them
*/
msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
/*
* Well, when DMA is ADM3 engine(implied by <= UARTDM v1.3),
* we need RXSTALE to flush input DMA fifo to memory
*/
if (msm_port->is_uartdm < UARTDM_1P4)
msm_port->imr |= UART_IMR_RXSTALE;
msm_write(uart, msm_port->imr, UART_IMR);
dma->count = UARTDM_RX_SIZE;
dma_async_issue_pending(dma->chan);
msm_write(uart, UART_CR_CMD_RESET_STALE_INT, UART_CR);
msm_write(uart, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
val = msm_read(uart, UARTDM_DMEN);
val |= dma->enable_bit;
if (msm_port->is_uartdm < UARTDM_1P4)
msm_write(uart, val, UARTDM_DMEN);
msm_write(uart, UARTDM_RX_SIZE, UARTDM_DMRX);
if (msm_port->is_uartdm > UARTDM_1P3)
msm_write(uart, val, UARTDM_DMEN);
return;
unmap:
dma_unmap_single(uart->dev, dma->phys, UARTDM_RX_SIZE, dma->dir);
}
static void msm_stop_rx(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
struct msm_dma *dma = &msm_port->rx_dma;
msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
msm_write(port, msm_port->imr, UART_IMR);
if (dma->chan)
msm_stop_dma(port, dma);
}
static void msm_enable_ms(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
msm_port->imr |= UART_IMR_DELTA_CTS;
msm_write(port, msm_port->imr, UART_IMR);
}
static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr)
{
struct tty_port *tport = &port->state->port;
unsigned int sr;
int count = 0;
struct msm_port *msm_port = UART_TO_MSM(port);
if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
port->icount.overrun++;
tty_insert_flip_char(tport, 0, TTY_OVERRUN);
msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
}
if (misr & UART_IMR_RXSTALE) {
count = msm_read(port, UARTDM_RX_TOTAL_SNAP) -
msm_port->old_snap_state;
msm_port->old_snap_state = 0;
} else {
count = 4 * (msm_read(port, UART_RFWR));
msm_port->old_snap_state += count;
}
/* TODO: Precise error reporting */
port->icount.rx += count;
while (count > 0) {
unsigned char buf[4];
int sysrq, r_count, i;
sr = msm_read(port, UART_SR);
if ((sr & UART_SR_RX_READY) == 0) {
msm_port->old_snap_state -= count;
break;
}
ioread32_rep(port->membase + UARTDM_RF, buf, 1);
r_count = min_t(int, count, sizeof(buf));
for (i = 0; i < r_count; i++) {
char flag = TTY_NORMAL;
if (msm_port->break_detected && buf[i] == 0) {
port->icount.brk++;
flag = TTY_BREAK;
msm_port->break_detected = false;
if (uart_handle_break(port))
continue;
}
if (!(port->read_status_mask & UART_SR_RX_BREAK))
flag = TTY_NORMAL;
spin_unlock(&port->lock);
sysrq = uart_handle_sysrq_char(port, buf[i]);
spin_lock(&port->lock);
if (!sysrq)
tty_insert_flip_char(tport, buf[i], flag);
}
count -= r_count;
}
spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
spin_lock(&port->lock);
if (misr & (UART_IMR_RXSTALE))
msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
msm_write(port, 0xFFFFFF, UARTDM_DMRX);
msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
/* Try to use DMA */
msm_start_rx_dma(msm_port);
}
static void msm_handle_rx(struct uart_port *port)
{
struct tty_port *tport = &port->state->port;
unsigned int sr;
/*
* Handle overrun. My understanding of the hardware is that overrun
* is not tied to the RX buffer, so we handle the case out of band.
*/
if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
port->icount.overrun++;
tty_insert_flip_char(tport, 0, TTY_OVERRUN);
msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
}
/* and now the main RX loop */
while ((sr = msm_read(port, UART_SR)) & UART_SR_RX_READY) {
unsigned int c;
char flag = TTY_NORMAL;
int sysrq;
c = msm_read(port, UART_RF);
if (sr & UART_SR_RX_BREAK) {
port->icount.brk++;
if (uart_handle_break(port))
continue;
} else if (sr & UART_SR_PAR_FRAME_ERR) {
port->icount.frame++;
} else {
port->icount.rx++;
}
/* Mask conditions we're ignorning. */
sr &= port->read_status_mask;
if (sr & UART_SR_RX_BREAK)
flag = TTY_BREAK;
else if (sr & UART_SR_PAR_FRAME_ERR)
flag = TTY_FRAME;
spin_unlock(&port->lock);
sysrq = uart_handle_sysrq_char(port, c);
spin_lock(&port->lock);
if (!sysrq)
tty_insert_flip_char(tport, c, flag);
}
spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
spin_lock(&port->lock);
}
static void msm_handle_tx_pio(struct uart_port *port, unsigned int tx_count)
{
struct circ_buf *xmit = &port->state->xmit;
struct msm_port *msm_port = UART_TO_MSM(port);
unsigned int num_chars;
unsigned int tf_pointer = 0;
void __iomem *tf;
if (msm_port->is_uartdm)
tf = port->membase + UARTDM_TF;
else
tf = port->membase + UART_TF;
if (tx_count && msm_port->is_uartdm)
msm_reset_dm_count(port, tx_count);
while (tf_pointer < tx_count) {
int i;
char buf[4] = { 0 };
if (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
break;
if (msm_port->is_uartdm)
num_chars = min(tx_count - tf_pointer,
(unsigned int)sizeof(buf));
else
num_chars = 1;
for (i = 0; i < num_chars; i++) {
buf[i] = xmit->buf[xmit->tail + i];
port->icount.tx++;
}
iowrite32_rep(tf, buf, 1);
xmit->tail = (xmit->tail + num_chars) & (UART_XMIT_SIZE - 1);
tf_pointer += num_chars;
}
/* disable tx interrupts if nothing more to send */
if (uart_circ_empty(xmit))
msm_stop_tx(port);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
}
static void msm_handle_tx(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
struct circ_buf *xmit = &msm_port->uart.state->xmit;
struct msm_dma *dma = &msm_port->tx_dma;
unsigned int pio_count, dma_count, dma_min;
void __iomem *tf;
int err = 0;
if (port->x_char) {
if (msm_port->is_uartdm)
tf = port->membase + UARTDM_TF;
else
tf = port->membase + UART_TF;
if (msm_port->is_uartdm)
msm_reset_dm_count(port, 1);
iowrite8_rep(tf, &port->x_char, 1);
port->icount.tx++;
port->x_char = 0;
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
msm_stop_tx(port);
return;
}
pio_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
dma_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
dma_min = 1; /* Always DMA */
if (msm_port->is_uartdm > UARTDM_1P3) {
dma_count = UARTDM_TX_AIGN(dma_count);
dma_min = UARTDM_BURST_SIZE;
} else {
if (dma_count > UARTDM_TX_MAX)
dma_count = UARTDM_TX_MAX;
}
if (pio_count > port->fifosize)
pio_count = port->fifosize;
if (!dma->chan || dma_count < dma_min)
msm_handle_tx_pio(port, pio_count);
else
err = msm_handle_tx_dma(msm_port, dma_count);
if (err) /* fall back to PIO mode */
msm_handle_tx_pio(port, pio_count);
}
static void msm_handle_delta_cts(struct uart_port *port)
{
msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
port->icount.cts++;
wake_up_interruptible(&port->state->port.delta_msr_wait);
}
static irqreturn_t msm_uart_irq(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct msm_port *msm_port = UART_TO_MSM(port);
struct msm_dma *dma = &msm_port->rx_dma;
unsigned long flags;
unsigned int misr;
u32 val;
spin_lock_irqsave(&port->lock, flags);
misr = msm_read(port, UART_MISR);
msm_write(port, 0, UART_IMR); /* disable interrupt */
if (misr & UART_IMR_RXBREAK_START) {
msm_port->break_detected = true;
msm_write(port, UART_CR_CMD_RESET_RXBREAK_START, UART_CR);
}
if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE)) {
if (dma->count) {
val = UART_CR_CMD_STALE_EVENT_DISABLE;
msm_write(port, val, UART_CR);
val = UART_CR_CMD_RESET_STALE_INT;
msm_write(port, val, UART_CR);
/*
* Flush DMA input fifo to memory, this will also
* trigger DMA RX completion
*/
dmaengine_terminate_all(dma->chan);
} else if (msm_port->is_uartdm) {
msm_handle_rx_dm(port, misr);
} else {
msm_handle_rx(port);
}
}
if (misr & UART_IMR_TXLEV)
msm_handle_tx(port);
if (misr & UART_IMR_DELTA_CTS)
msm_handle_delta_cts(port);
msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */
spin_unlock_irqrestore(&port->lock, flags);
return IRQ_HANDLED;
}
static unsigned int msm_tx_empty(struct uart_port *port)
{
return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
}
static unsigned int msm_get_mctrl(struct uart_port *port)
{
return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS;
}
static void msm_reset(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
/* reset everything */
msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR);
msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
msm_write(port, UART_CR_CMD_SET_RFR, UART_CR);
/* Disable DM modes */
if (msm_port->is_uartdm)
msm_write(port, 0, UARTDM_DMEN);
}
static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
unsigned int mr;
mr = msm_read(port, UART_MR1);
if (!(mctrl & TIOCM_RTS)) {
mr &= ~UART_MR1_RX_RDY_CTL;
msm_write(port, mr, UART_MR1);
msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR);
} else {
mr |= UART_MR1_RX_RDY_CTL;
msm_write(port, mr, UART_MR1);
}
}
static void msm_break_ctl(struct uart_port *port, int break_ctl)
{
if (break_ctl)
msm_write(port, UART_CR_CMD_START_BREAK, UART_CR);
else
msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR);
}
struct msm_baud_map {
u16 divisor;
u8 code;
u8 rxstale;
};
static const struct msm_baud_map *
msm_find_best_baud(struct uart_port *port, unsigned int baud)
{
unsigned int i, divisor;
const struct msm_baud_map *entry;
static const struct msm_baud_map table[] = {
{ 1536, 0x00, 1 },
{ 768, 0x11, 1 },
{ 384, 0x22, 1 },
{ 192, 0x33, 1 },
{ 96, 0x44, 1 },
{ 48, 0x55, 1 },
{ 32, 0x66, 1 },
{ 24, 0x77, 1 },
{ 16, 0x88, 1 },
{ 12, 0x99, 6 },
{ 8, 0xaa, 6 },
{ 6, 0xbb, 6 },
{ 4, 0xcc, 6 },
{ 3, 0xdd, 8 },
{ 2, 0xee, 16 },
{ 1, 0xff, 31 },
{ 0, 0xff, 31 },
};
divisor = uart_get_divisor(port, baud);
for (i = 0, entry = table; i < ARRAY_SIZE(table); i++, entry++)
if (entry->divisor <= divisor)
break;
return entry; /* Default to smallest divider */
}
static int msm_set_baud_rate(struct uart_port *port, unsigned int baud,
unsigned long *saved_flags)
{
unsigned int rxstale, watermark, mask;
struct msm_port *msm_port = UART_TO_MSM(port);
const struct msm_baud_map *entry;
unsigned long flags;
entry = msm_find_best_baud(port, baud);
msm_write(port, entry->code, UART_CSR);
if (baud > 460800)
port->uartclk = baud * 16;
flags = *saved_flags;
spin_unlock_irqrestore(&port->lock, flags);
clk_set_rate(msm_port->clk, port->uartclk);
spin_lock_irqsave(&port->lock, flags);
*saved_flags = flags;
/* RX stale watermark */
rxstale = entry->rxstale;
watermark = UART_IPR_STALE_LSB & rxstale;
if (msm_port->is_uartdm) {
mask = UART_DM_IPR_STALE_TIMEOUT_MSB;
} else {
watermark |= UART_IPR_RXSTALE_LAST;
mask = UART_IPR_STALE_TIMEOUT_MSB;
}
watermark |= mask & (rxstale << 2);
msm_write(port, watermark, UART_IPR);
/* set RX watermark */
watermark = (port->fifosize * 3) / 4;
msm_write(port, watermark, UART_RFWR);
/* set TX watermark */
msm_write(port, 10, UART_TFWR);
msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR);
msm_reset(port);
/* Enable RX and TX */
msm_write(port, UART_CR_TX_ENABLE | UART_CR_RX_ENABLE, UART_CR);
/* turn on RX and CTS interrupts */
msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE |
UART_IMR_CURRENT_CTS | UART_IMR_RXBREAK_START;
msm_write(port, msm_port->imr, UART_IMR);
if (msm_port->is_uartdm) {
msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
msm_write(port, 0xFFFFFF, UARTDM_DMRX);
msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
}
return baud;
}
static void msm_init_clock(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
clk_prepare_enable(msm_port->clk);
clk_prepare_enable(msm_port->pclk);
msm_serial_set_mnd_regs(port);
}
static int msm_startup(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
unsigned int data, rfr_level, mask;
int ret;
snprintf(msm_port->name, sizeof(msm_port->name),
"msm_serial%d", port->line);
ret = request_irq(port->irq, msm_uart_irq, IRQF_TRIGGER_HIGH,
msm_port->name, port);
if (unlikely(ret))
return ret;
msm_init_clock(port);
if (likely(port->fifosize > 12))
rfr_level = port->fifosize - 12;
else
rfr_level = port->fifosize;
/* set automatic RFR level */
data = msm_read(port, UART_MR1);
if (msm_port->is_uartdm)
mask = UART_DM_MR1_AUTO_RFR_LEVEL1;
else
mask = UART_MR1_AUTO_RFR_LEVEL1;
data &= ~mask;
data &= ~UART_MR1_AUTO_RFR_LEVEL0;
data |= mask & (rfr_level << 2);
data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level;
msm_write(port, data, UART_MR1);
if (msm_port->is_uartdm) {
msm_request_tx_dma(msm_port, msm_port->uart.mapbase);
msm_request_rx_dma(msm_port, msm_port->uart.mapbase);
}
return 0;
}
static void msm_shutdown(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
msm_port->imr = 0;
msm_write(port, 0, UART_IMR); /* disable interrupts */
if (msm_port->is_uartdm)
msm_release_dma(msm_port);
clk_disable_unprepare(msm_port->clk);
free_irq(port->irq, port);
}
static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
struct msm_port *msm_port = UART_TO_MSM(port);
struct msm_dma *dma = &msm_port->rx_dma;
unsigned long flags;
unsigned int baud, mr;
spin_lock_irqsave(&port->lock, flags);
if (dma->chan) /* Terminate if any */
msm_stop_dma(port, dma);
/* calculate and set baud rate */
baud = uart_get_baud_rate(port, termios, old, 300, 4000000);
baud = msm_set_baud_rate(port, baud, &flags);
if (tty_termios_baud_rate(termios))
tty_termios_encode_baud_rate(termios, baud, baud);
/* calculate parity */
mr = msm_read(port, UART_MR2);
mr &= ~UART_MR2_PARITY_MODE;
if (termios->c_cflag & PARENB) {
if (termios->c_cflag & PARODD)
mr |= UART_MR2_PARITY_MODE_ODD;
else if (termios->c_cflag & CMSPAR)
mr |= UART_MR2_PARITY_MODE_SPACE;
else
mr |= UART_MR2_PARITY_MODE_EVEN;
}
/* calculate bits per char */
mr &= ~UART_MR2_BITS_PER_CHAR;
switch (termios->c_cflag & CSIZE) {
case CS5:
mr |= UART_MR2_BITS_PER_CHAR_5;
break;
case CS6:
mr |= UART_MR2_BITS_PER_CHAR_6;
break;
case CS7:
mr |= UART_MR2_BITS_PER_CHAR_7;
break;
case CS8:
default:
mr |= UART_MR2_BITS_PER_CHAR_8;
break;
}
/* calculate stop bits */
mr &= ~(UART_MR2_STOP_BIT_LEN_ONE | UART_MR2_STOP_BIT_LEN_TWO);
if (termios->c_cflag & CSTOPB)
mr |= UART_MR2_STOP_BIT_LEN_TWO;
else
mr |= UART_MR2_STOP_BIT_LEN_ONE;
/* set parity, bits per char, and stop bit */
msm_write(port, mr, UART_MR2);
/* calculate and set hardware flow control */
mr = msm_read(port, UART_MR1);
mr &= ~(UART_MR1_CTS_CTL | UART_MR1_RX_RDY_CTL);
if (termios->c_cflag & CRTSCTS) {
mr |= UART_MR1_CTS_CTL;
mr |= UART_MR1_RX_RDY_CTL;
}
msm_write(port, mr, UART_MR1);
/* Configure status bits to ignore based on termio flags. */
port->read_status_mask = 0;
if (termios->c_iflag & INPCK)
port->read_status_mask |= UART_SR_PAR_FRAME_ERR;
if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
port->read_status_mask |= UART_SR_RX_BREAK;
uart_update_timeout(port, termios->c_cflag, baud);
/* Try to use DMA */
msm_start_rx_dma(msm_port);
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *msm_type(struct uart_port *port)
{
return "MSM";
}
static void msm_release_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
struct resource *uart_resource;
resource_size_t size;
uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (unlikely(!uart_resource))
return;
size = resource_size(uart_resource);
release_mem_region(port->mapbase, size);
iounmap(port->membase);
port->membase = NULL;
}
static int msm_request_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
struct resource *uart_resource;
resource_size_t size;
int ret;
uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (unlikely(!uart_resource))
return -ENXIO;
size = resource_size(uart_resource);
if (!request_mem_region(port->mapbase, size, "msm_serial"))
return -EBUSY;
port->membase = ioremap(port->mapbase, size);
if (!port->membase) {
ret = -EBUSY;
goto fail_release_port;
}
return 0;
fail_release_port:
release_mem_region(port->mapbase, size);
return ret;
}
static void msm_config_port(struct uart_port *port, int flags)
{
int ret;
if (flags & UART_CONFIG_TYPE) {
port->type = PORT_MSM;
ret = msm_request_port(port);
if (ret)
return;
}
}
static int msm_verify_port(struct uart_port *port, struct serial_struct *ser)
{
if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM))
return -EINVAL;
if (unlikely(port->irq != ser->irq))
return -EINVAL;
return 0;
}
static void msm_power(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
struct msm_port *msm_port = UART_TO_MSM(port);
switch (state) {
case 0:
clk_prepare_enable(msm_port->clk);
clk_prepare_enable(msm_port->pclk);
break;
case 3:
clk_disable_unprepare(msm_port->clk);
clk_disable_unprepare(msm_port->pclk);
break;
default:
pr_err("msm_serial: Unknown PM state %d\n", state);
}
}
#ifdef CONFIG_CONSOLE_POLL
static int msm_poll_get_char_single(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : UART_RF;
if (!(msm_read(port, UART_SR) & UART_SR_RX_READY))
return NO_POLL_CHAR;
return msm_read(port, rf_reg) & 0xff;
}
static int msm_poll_get_char_dm(struct uart_port *port)
{
int c;
static u32 slop;
static int count;
unsigned char *sp = (unsigned char *)&slop;
/* Check if a previous read had more than one char */
if (count) {
c = sp[sizeof(slop) - count];
count--;
/* Or if FIFO is empty */
} else if (!(msm_read(port, UART_SR) & UART_SR_RX_READY)) {
/*
* If RX packing buffer has less than a word, force stale to
* push contents into RX FIFO
*/
count = msm_read(port, UARTDM_RXFS);
count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK;
if (count) {
msm_write(port, UART_CR_CMD_FORCE_STALE, UART_CR);
slop = msm_read(port, UARTDM_RF);
c = sp[0];
count--;
msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
msm_write(port, 0xFFFFFF, UARTDM_DMRX);
msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE,
UART_CR);
} else {
c = NO_POLL_CHAR;
}
/* FIFO has a word */
} else {
slop = msm_read(port, UARTDM_RF);
c = sp[0];
count = sizeof(slop) - 1;
}
return c;
}
static int msm_poll_get_char(struct uart_port *port)
{
u32 imr;
int c;
struct msm_port *msm_port = UART_TO_MSM(port);
/* Disable all interrupts */
imr = msm_read(port, UART_IMR);
msm_write(port, 0, UART_IMR);
if (msm_port->is_uartdm)
c = msm_poll_get_char_dm(port);
else
c = msm_poll_get_char_single(port);
/* Enable interrupts */
msm_write(port, imr, UART_IMR);
return c;
}
static void msm_poll_put_char(struct uart_port *port, unsigned char c)
{
u32 imr;
struct msm_port *msm_port = UART_TO_MSM(port);
/* Disable all interrupts */
imr = msm_read(port, UART_IMR);
msm_write(port, 0, UART_IMR);
if (msm_port->is_uartdm)
msm_reset_dm_count(port, 1);
/* Wait until FIFO is empty */
while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
cpu_relax();
/* Write a character */
msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
/* Wait until FIFO is empty */
while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
cpu_relax();
/* Enable interrupts */
msm_write(port, imr, UART_IMR);
}
#endif
static struct uart_ops msm_uart_pops = {
.tx_empty = msm_tx_empty,
.set_mctrl = msm_set_mctrl,
.get_mctrl = msm_get_mctrl,
.stop_tx = msm_stop_tx,
.start_tx = msm_start_tx,
.stop_rx = msm_stop_rx,
.enable_ms = msm_enable_ms,
.break_ctl = msm_break_ctl,
.startup = msm_startup,
.shutdown = msm_shutdown,
.set_termios = msm_set_termios,
.type = msm_type,
.release_port = msm_release_port,
.request_port = msm_request_port,
.config_port = msm_config_port,
.verify_port = msm_verify_port,
.pm = msm_power,
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = msm_poll_get_char,
.poll_put_char = msm_poll_put_char,
#endif
};
static struct msm_port msm_uart_ports[] = {
{
.uart = {
.iotype = UPIO_MEM,
.ops = &msm_uart_pops,
.flags = UPF_BOOT_AUTOCONF,
.fifosize = 64,
.line = 0,
},
},
{
.uart = {
.iotype = UPIO_MEM,
.ops = &msm_uart_pops,
.flags = UPF_BOOT_AUTOCONF,
.fifosize = 64,
.line = 1,
},
},
{
.uart = {
.iotype = UPIO_MEM,
.ops = &msm_uart_pops,
.flags = UPF_BOOT_AUTOCONF,
.fifosize = 64,
.line = 2,
},
},
};
#define UART_NR ARRAY_SIZE(msm_uart_ports)
static inline struct uart_port *msm_get_port_from_line(unsigned int line)
{
return &msm_uart_ports[line].uart;
}
#ifdef CONFIG_SERIAL_MSM_CONSOLE
static void __msm_console_write(struct uart_port *port, const char *s,
unsigned int count, bool is_uartdm)
{
int i;
int num_newlines = 0;
bool replaced = false;
void __iomem *tf;
if (is_uartdm)
tf = port->membase + UARTDM_TF;
else
tf = port->membase + UART_TF;
/* Account for newlines that will get a carriage return added */
for (i = 0; i < count; i++)
if (s[i] == '\n')
num_newlines++;
count += num_newlines;
spin_lock(&port->lock);
if (is_uartdm)
msm_reset_dm_count(port, count);
i = 0;
while (i < count) {
int j;
unsigned int num_chars;
char buf[4] = { 0 };
if (is_uartdm)
num_chars = min(count - i, (unsigned int)sizeof(buf));
else
num_chars = 1;
for (j = 0; j < num_chars; j++) {
char c = *s;
if (c == '\n' && !replaced) {
buf[j] = '\r';
j++;
replaced = true;
}
if (j < num_chars) {
buf[j] = c;
s++;
replaced = false;
}
}
while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
cpu_relax();
iowrite32_rep(tf, buf, 1);
i += num_chars;
}
spin_unlock(&port->lock);
}
static void msm_console_write(struct console *co, const char *s,
unsigned int count)
{
struct uart_port *port;
struct msm_port *msm_port;
BUG_ON(co->index < 0 || co->index >= UART_NR);
port = msm_get_port_from_line(co->index);
msm_port = UART_TO_MSM(port);
__msm_console_write(port, s, count, msm_port->is_uartdm);
}
static int __init msm_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (unlikely(co->index >= UART_NR || co->index < 0))
return -ENXIO;
port = msm_get_port_from_line(co->index);
if (unlikely(!port->membase))
return -ENXIO;
msm_init_clock(port);
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
pr_info("msm_serial: console setup on port #%d\n", port->line);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static void
msm_serial_early_write(struct console *con, const char *s, unsigned n)
{
struct earlycon_device *dev = con->data;
__msm_console_write(&dev->port, s, n, false);
}
static int __init
msm_serial_early_console_setup(struct earlycon_device *device, const char *opt)
{
if (!device->port.membase)
return -ENODEV;
device->con->write = msm_serial_early_write;
return 0;
}
OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart",
msm_serial_early_console_setup);
static void
msm_serial_early_write_dm(struct console *con, const char *s, unsigned n)
{
struct earlycon_device *dev = con->data;
__msm_console_write(&dev->port, s, n, true);
}
static int __init
msm_serial_early_console_setup_dm(struct earlycon_device *device,
const char *opt)
{
if (!device->port.membase)
return -ENODEV;
device->con->write = msm_serial_early_write_dm;
return 0;
}
OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm",
msm_serial_early_console_setup_dm);
static struct uart_driver msm_uart_driver;
static struct console msm_console = {
.name = "ttyMSM",
.write = msm_console_write,
.device = uart_console_device,
.setup = msm_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &msm_uart_driver,
};
#define MSM_CONSOLE (&msm_console)
#else
#define MSM_CONSOLE NULL
#endif
static struct uart_driver msm_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "msm_serial",
.dev_name = "ttyMSM",
.nr = UART_NR,
.cons = MSM_CONSOLE,
};
static atomic_t msm_uart_next_id = ATOMIC_INIT(0);
static const struct of_device_id msm_uartdm_table[] = {
{ .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 },
{ .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 },
{ .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 },
{ .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 },
{ }
};
static int msm_serial_probe(struct platform_device *pdev)
{
struct msm_port *msm_port;
struct resource *resource;
struct uart_port *port;
const struct of_device_id *id;
int irq, line;
if (pdev->dev.of_node)
line = of_alias_get_id(pdev->dev.of_node, "serial");
else
line = pdev->id;
if (line < 0)
line = atomic_inc_return(&msm_uart_next_id) - 1;
if (unlikely(line < 0 || line >= UART_NR))
return -ENXIO;
dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line);
port = msm_get_port_from_line(line);
port->dev = &pdev->dev;
msm_port = UART_TO_MSM(port);
id = of_match_device(msm_uartdm_table, &pdev->dev);
if (id)
msm_port->is_uartdm = (unsigned long)id->data;
else
msm_port->is_uartdm = 0;
msm_port->clk = devm_clk_get(&pdev->dev, "core");
if (IS_ERR(msm_port->clk))
return PTR_ERR(msm_port->clk);
if (msm_port->is_uartdm) {
msm_port->pclk = devm_clk_get(&pdev->dev, "iface");
if (IS_ERR(msm_port->pclk))
return PTR_ERR(msm_port->pclk);
clk_set_rate(msm_port->clk, 1843200);
}
port->uartclk = clk_get_rate(msm_port->clk);
dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk);
resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (unlikely(!resource))
return -ENXIO;
port->mapbase = resource->start;
irq = platform_get_irq(pdev, 0);
if (unlikely(irq < 0))
return -ENXIO;
port->irq = irq;
platform_set_drvdata(pdev, port);
return uart_add_one_port(&msm_uart_driver, port);
}
static int msm_serial_remove(struct platform_device *pdev)
{
struct uart_port *port = platform_get_drvdata(pdev);
uart_remove_one_port(&msm_uart_driver, port);
return 0;
}
static const struct of_device_id msm_match_table[] = {
{ .compatible = "qcom,msm-uart" },
{ .compatible = "qcom,msm-uartdm" },
{}
};
static struct platform_driver msm_platform_driver = {
.remove = msm_serial_remove,
.probe = msm_serial_probe,
.driver = {
.name = "msm_serial",
.of_match_table = msm_match_table,
},
};
static int __init msm_serial_init(void)
{
int ret;
ret = uart_register_driver(&msm_uart_driver);
if (unlikely(ret))
return ret;
ret = platform_driver_register(&msm_platform_driver);
if (unlikely(ret))
uart_unregister_driver(&msm_uart_driver);
pr_info("msm_serial: driver initialized\n");
return ret;
}
static void __exit msm_serial_exit(void)
{
platform_driver_unregister(&msm_platform_driver);
uart_unregister_driver(&msm_uart_driver);
}
module_init(msm_serial_init);
module_exit(msm_serial_exit);
MODULE_AUTHOR("Robert Love <rlove@google.com>");
MODULE_DESCRIPTION("Driver for msm7x serial device");
MODULE_LICENSE("GPL");
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