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serial: mxs-auart: add interrupts for modem control lines 

Handle CTS/DSR/RI/DCD GPIO interrupts in mxs-auart.

Signed-off-by: Janusz Uzycki <j.uzycki@elproma.com.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Janusz Uzycki 2014-10-10 18:53:26 +02:00 committed by Greg Kroah-Hartman
parent 7c573d7ea6
commit f9e42397d7
1 changed files with 172 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

174
drivers/tty/serial/mxs-auart.c
View File

@ -42,7 +42,10 @@
#include <asm/cacheflush.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/err.h>
#include <linux/irq.h>
#include "serial_mctrl_gpio.h"
#define MXS_AUART_PORTS 5
@ -146,6 +149,7 @@ struct mxs_auart_port {
#define MXS_AUART_DMA_RX_READY 3 /* bit 3 */
#define MXS_AUART_RTSCTS 4 /* bit 4 */
unsigned long flags;
unsigned int mctrl_prev;
enum mxs_auart_type devtype;
unsigned int irq;
@ -163,6 +167,8 @@ struct mxs_auart_port {
void *rx_dma_buf;
struct mctrl_gpios *gpios;
int gpio_irq[UART_GPIO_MAX];
bool ms_irq_enabled;
};
static struct platform_device_id mxs_auart_devtype[] = {
@ -427,6 +433,29 @@ static void mxs_auart_set_mctrl(struct uart_port *u, unsigned mctrl)
mctrl_gpio_set(s->gpios, mctrl);
}
#define MCTRL_ANY_DELTA (TIOCM_RI | TIOCM_DSR | TIOCM_CD | TIOCM_CTS)
static u32 mxs_auart_modem_status(struct mxs_auart_port *s, u32 mctrl)
{
u32 mctrl_diff;
mctrl_diff = mctrl ^ s->mctrl_prev;
s->mctrl_prev = mctrl;
if (mctrl_diff & MCTRL_ANY_DELTA && s->ms_irq_enabled &&
s->port.state != NULL) {
if (mctrl_diff & TIOCM_RI)
s->port.icount.rng++;
if (mctrl_diff & TIOCM_DSR)
s->port.icount.dsr++;
if (mctrl_diff & TIOCM_CD)
uart_handle_dcd_change(&s->port, mctrl & TIOCM_CD);
if (mctrl_diff & TIOCM_CTS)
uart_handle_cts_change(&s->port, mctrl & TIOCM_CTS);
wake_up_interruptible(&s->port.state->port.delta_msr_wait);
}
return mctrl;
}
static u32 mxs_auart_get_mctrl(struct uart_port *u)
{
struct mxs_auart_port *s = to_auart_port(u);
@ -439,6 +468,64 @@ static u32 mxs_auart_get_mctrl(struct uart_port *u)
return mctrl_gpio_get(s->gpios, &mctrl);
}
/*
* Enable modem status interrupts
*/
static void mxs_auart_enable_ms(struct uart_port *port)
{
struct mxs_auart_port *s = to_auart_port(port);
/*
* Interrupt should not be enabled twice
*/
if (s->ms_irq_enabled)
return;
s->ms_irq_enabled = true;
if (s->gpio_irq[UART_GPIO_CTS] >= 0)
enable_irq(s->gpio_irq[UART_GPIO_CTS]);
/* TODO: enable AUART_INTR_CTSMIEN otherwise */
if (s->gpio_irq[UART_GPIO_DSR] >= 0)
enable_irq(s->gpio_irq[UART_GPIO_DSR]);
if (s->gpio_irq[UART_GPIO_RI] >= 0)
enable_irq(s->gpio_irq[UART_GPIO_RI]);
if (s->gpio_irq[UART_GPIO_DCD] >= 0)
enable_irq(s->gpio_irq[UART_GPIO_DCD]);
}
/*
* Disable modem status interrupts
*/
static void mxs_auart_disable_ms(struct uart_port *port)
{
struct mxs_auart_port *s = to_auart_port(port);
/*
* Interrupt should not be disabled twice
*/
if (!s->ms_irq_enabled)
return;
s->ms_irq_enabled = false;
if (s->gpio_irq[UART_GPIO_CTS] >= 0)
disable_irq(s->gpio_irq[UART_GPIO_CTS]);
/* TODO: disable AUART_INTR_CTSMIEN otherwise */
if (s->gpio_irq[UART_GPIO_DSR] >= 0)
disable_irq(s->gpio_irq[UART_GPIO_DSR]);
if (s->gpio_irq[UART_GPIO_RI] >= 0)
disable_irq(s->gpio_irq[UART_GPIO_RI]);
if (s->gpio_irq[UART_GPIO_DCD] >= 0)
disable_irq(s->gpio_irq[UART_GPIO_DCD]);
}
static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s);
static void dma_rx_callback(void *arg)
{
@ -689,6 +776,12 @@ static void mxs_auart_settermios(struct uart_port *u,
dev_err(s->dev, "We can not start up the DMA.\n");
}
}
/* CTS flow-control and modem-status interrupts */
if (UART_ENABLE_MS(u, termios->c_cflag))
mxs_auart_enable_ms(u);
else
mxs_auart_disable_ms(u);
}
static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
@ -706,8 +799,18 @@ static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
| AUART_INTR_CTSMIS),
s->port.membase + AUART_INTR_CLR);
/*
* Dealing with GPIO interrupt
*/
if (irq == s->gpio_irq[UART_GPIO_CTS] ||
irq == s->gpio_irq[UART_GPIO_DCD] ||
irq == s->gpio_irq[UART_GPIO_DSR] ||
irq == s->gpio_irq[UART_GPIO_RI])
mxs_auart_modem_status(s,
mctrl_gpio_get(s->gpios, &s->mctrl_prev));
if (istat & AUART_INTR_CTSMIS) {
if (CTS_AT_AUART())
if (CTS_AT_AUART() && s->ms_irq_enabled)
uart_handle_cts_change(&s->port,
stat & AUART_STAT_CTS);
writel(AUART_INTR_CTSMIS,
@ -770,6 +873,10 @@ static int mxs_auart_startup(struct uart_port *u)
*/
writel(AUART_LINECTRL_FEN, u->membase + AUART_LINECTRL_SET);
/* get initial status of modem lines */
mctrl_gpio_get(s->gpios, &s->mctrl_prev);
s->ms_irq_enabled = false;
return 0;
}
@ -777,6 +884,8 @@ static void mxs_auart_shutdown(struct uart_port *u)
{
struct mxs_auart_port *s = to_auart_port(u);
mxs_auart_disable_ms(u);
if (auart_dma_enabled(s))
mxs_auart_dma_exit(s);
@ -833,6 +942,7 @@ static struct uart_ops mxs_auart_ops = {
.start_tx = mxs_auart_start_tx,
.stop_tx = mxs_auart_stop_tx,
.stop_rx = mxs_auart_stop_rx,
.enable_ms = mxs_auart_enable_ms,
.break_ctl = mxs_auart_break_ctl,
.set_mctrl = mxs_auart_set_mctrl,
.get_mctrl = mxs_auart_get_mctrl,
@ -1035,6 +1145,9 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s,
static bool mxs_auart_init_gpios(struct mxs_auart_port *s, struct device *dev)
{
enum mctrl_gpio_idx i;
struct gpio_desc *gpiod;
s->gpios = mctrl_gpio_init(dev, 0);
if (IS_ERR_OR_NULL(s->gpios))
return false;
@ -1047,9 +1160,54 @@ static bool mxs_auart_init_gpios(struct mxs_auart_port *s, struct device *dev)
clear_bit(MXS_AUART_RTSCTS, &s->flags);
}
for (i = 0; i < UART_GPIO_MAX; i++) {
gpiod = mctrl_gpio_to_gpiod(s->gpios, i);
if (gpiod && (gpiod_get_direction(gpiod) == GPIOF_DIR_IN))
s->gpio_irq[i] = gpiod_to_irq(gpiod);
else
s->gpio_irq[i] = -EINVAL;
}
return true;
}
static void mxs_auart_free_gpio_irq(struct mxs_auart_port *s)
{
enum mctrl_gpio_idx i;
for (i = 0; i < UART_GPIO_MAX; i++)
if (s->gpio_irq[i] >= 0)
free_irq(s->gpio_irq[i], s);
}
static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s)
{
int *irq = s->gpio_irq;
enum mctrl_gpio_idx i;
int err = 0;
for (i = 0; (i < UART_GPIO_MAX) && !err; i++) {
if (irq[i] < 0)
continue;
irq_set_status_flags(irq[i], IRQ_NOAUTOEN);
err = request_irq(irq[i], mxs_auart_irq_handle,
IRQ_TYPE_EDGE_BOTH, dev_name(s->dev), s);
if (err)
dev_err(s->dev, "%s - Can't get %d irq\n",
__func__, irq[i]);
}
/*
* If something went wrong, rollback.
*/
while (err && (--i >= 0))
if (irq[i] >= 0)
free_irq(irq[i], s);
return err;
}
static int mxs_auart_probe(struct platform_device *pdev)
{
const struct of_device_id *of_id =
@ -1097,6 +1255,8 @@ static int mxs_auart_probe(struct platform_device *pdev)
s->port.type = PORT_IMX;
s->port.dev = s->dev = &pdev->dev;
s->mctrl_prev = 0;
s->irq = platform_get_irq(pdev, 0);
s->port.irq = s->irq;
ret = request_irq(s->irq, mxs_auart_irq_handle, 0, dev_name(&pdev->dev), s);
@ -1109,13 +1269,20 @@ static int mxs_auart_probe(struct platform_device *pdev)
dev_err(&pdev->dev,
"Failed to initialize GPIOs. The serial port may not work as expected\n");
/*
* Get the GPIO lines IRQ
*/
ret = mxs_auart_request_gpio_irq(s);
if (ret)
goto out_free_irq;
auart_port[s->port.line] = s;
mxs_auart_reset(&s->port);
ret = uart_add_one_port(&auart_driver, &s->port);
if (ret)
goto out_free_irq;
goto out_free_gpio_irq;
version = readl(s->port.membase + AUART_VERSION);
dev_info(&pdev->dev, "Found APPUART %d.%d.%d\n",
@ -1124,6 +1291,8 @@ static int mxs_auart_probe(struct platform_device *pdev)
return 0;
out_free_gpio_irq:
mxs_auart_free_gpio_irq(s);
out_free_irq:
auart_port[pdev->id] = NULL;
free_irq(s->irq, s);
@ -1143,6 +1312,7 @@ static int mxs_auart_remove(struct platform_device *pdev)
auart_port[pdev->id] = NULL;
mxs_auart_free_gpio_irq(s);
clk_put(s->clk);
free_irq(s->irq, s);
kfree(s);