tty/serial: at91: add interrupts for modem control lines

Handle CTS/DSR/RI/DCD GPIO interrupts in atmel_serial.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Richard Genoud 2014-05-13 20:20:45 +02:00 committed by Greg Kroah-Hartman
parent e0b0baadb7
commit ab5e4e4108
1 changed files with 122 additions and 3 deletions

View File

@ -45,6 +45,7 @@
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/err.h>
#include <linux/irq.h>
#include <asm/io.h>
#include <asm/ioctls.h>
@ -167,7 +168,9 @@ struct atmel_uart_port {
struct serial_rs485 rs485; /* rs485 settings */
struct mctrl_gpios *gpios;
int gpio_irq[UART_GPIO_MAX];
unsigned int tx_done_mask;
bool ms_irq_enabled;
bool is_usart; /* usart or uart */
struct timer_list uart_timer; /* uart timer */
int (*prepare_rx)(struct uart_port *port);
@ -489,8 +492,38 @@ static void atmel_stop_rx(struct uart_port *port)
*/
static void atmel_enable_ms(struct uart_port *port)
{
UART_PUT_IER(port, ATMEL_US_RIIC | ATMEL_US_DSRIC
| ATMEL_US_DCDIC | ATMEL_US_CTSIC);
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
uint32_t ier = 0;
/*
* Interrupt should not be enabled twice
*/
if (atmel_port->ms_irq_enabled)
return;
atmel_port->ms_irq_enabled = true;
if (atmel_port->gpio_irq[UART_GPIO_CTS] >= 0)
enable_irq(atmel_port->gpio_irq[UART_GPIO_CTS]);
else
ier |= ATMEL_US_CTSIC;
if (atmel_port->gpio_irq[UART_GPIO_DSR] >= 0)
enable_irq(atmel_port->gpio_irq[UART_GPIO_DSR]);
else
ier |= ATMEL_US_DSRIC;
if (atmel_port->gpio_irq[UART_GPIO_RI] >= 0)
enable_irq(atmel_port->gpio_irq[UART_GPIO_RI]);
else
ier |= ATMEL_US_RIIC;
if (atmel_port->gpio_irq[UART_GPIO_DCD] >= 0)
enable_irq(atmel_port->gpio_irq[UART_GPIO_DCD]);
else
ier |= ATMEL_US_DCDIC;
UART_PUT_IER(port, ier);
}
/*
@ -1079,11 +1112,31 @@ atmel_handle_status(struct uart_port *port, unsigned int pending,
static irqreturn_t atmel_interrupt(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
unsigned int status, pending, pass_counter = 0;
bool gpio_handled = false;
do {
status = atmel_get_lines_status(port);
pending = status & UART_GET_IMR(port);
if (!gpio_handled) {
/*
* Dealing with GPIO interrupt
*/
if (irq == atmel_port->gpio_irq[UART_GPIO_CTS])
pending |= ATMEL_US_CTSIC;
if (irq == atmel_port->gpio_irq[UART_GPIO_DSR])
pending |= ATMEL_US_DSRIC;
if (irq == atmel_port->gpio_irq[UART_GPIO_RI])
pending |= ATMEL_US_RIIC;
if (irq == atmel_port->gpio_irq[UART_GPIO_DCD])
pending |= ATMEL_US_DCDIC;
gpio_handled = true;
}
if (!pending)
break;
@ -1563,6 +1616,45 @@ static void atmel_get_ip_name(struct uart_port *port)
}
}
static void atmel_free_gpio_irq(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
enum mctrl_gpio_idx i;
for (i = 0; i < UART_GPIO_MAX; i++)
if (atmel_port->gpio_irq[i] >= 0)
free_irq(atmel_port->gpio_irq[i], port);
}
static int atmel_request_gpio_irq(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
int *irq = atmel_port->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], atmel_interrupt, IRQ_TYPE_EDGE_BOTH,
"atmel_serial", port);
if (err)
dev_err(port->dev, "atmel_startup - Can't get %d irq\n",
irq[i]);
}
/*
* If something went wrong, rollback.
*/
while (err && (--i >= 0))
if (irq[i] >= 0)
free_irq(irq[i], port);
return err;
}
/*
* Perform initialization and enable port for reception
*/
@ -1579,6 +1671,7 @@ static int atmel_startup(struct uart_port *port)
* handle an unexpected interrupt
*/
UART_PUT_IDR(port, -1);
atmel_port->ms_irq_enabled = false;
/*
* Allocate the IRQ
@ -1590,6 +1683,13 @@ static int atmel_startup(struct uart_port *port)
return retval;
}
/*
* Get the GPIO lines IRQ
*/
retval = atmel_request_gpio_irq(port);
if (retval)
goto free_irq;
/*
* Initialize DMA (if necessary)
*/
@ -1654,6 +1754,11 @@ static int atmel_startup(struct uart_port *port)
}
return 0;
free_irq:
free_irq(port->irq, port);
return retval;
}
/*
@ -1701,9 +1806,12 @@ static void atmel_shutdown(struct uart_port *port)
atmel_port->rx_ring.tail = 0;
/*
* Free the interrupt
* Free the interrupts
*/
free_irq(port->irq, port);
atmel_free_gpio_irq(port);
atmel_port->ms_irq_enabled = false;
}
/*
@ -2366,10 +2474,21 @@ static int atmel_serial_resume(struct platform_device *pdev)
static int atmel_init_gpios(struct atmel_uart_port *p, struct device *dev)
{
enum mctrl_gpio_idx i;
struct gpio_desc *gpiod;
p->gpios = mctrl_gpio_init(dev, 0);
if (IS_ERR_OR_NULL(p->gpios))
return -1;
for (i = 0; i < UART_GPIO_MAX; i++) {
gpiod = mctrl_gpio_to_gpiod(p->gpios, i);
if (gpiod && (gpiod_get_direction(gpiod) == GPIOF_DIR_IN))
p->gpio_irq[i] = gpiod_to_irq(gpiod);
else
p->gpio_irq[i] = -EINVAL;
}
return 0;
}