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authorRichard Genoud <richard.genoud@gmail.com>2014-05-13 20:20:45 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-05-28 12:51:18 -0700
commitab5e4e4108ca5d8326cb6b4b3a21b096a002f68f (patch)
tree4908be40a0d34a8cd5b1c71b938c7f923cff9a06
parente0b0baadb7a4509bdcd5ba37d0be61e2c4bb0d48 (diff)
downloadlinux-ab5e4e4108ca5d8326cb6b4b3a21b096a002f68f.tar.gz
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>
-rw-r--r--drivers/tty/serial/atmel_serial.c125
1 files changed, 122 insertions, 3 deletions
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 43ca659c1d4b..3fceae099c44 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -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
@@ -1591,6 +1684,13 @@ static int atmel_startup(struct uart_port *port)
}
/*
+ * Get the GPIO lines IRQ
+ */
+ retval = atmel_request_gpio_irq(port);
+ if (retval)
+ goto free_irq;
+
+ /*
* Initialize DMA (if necessary)
*/
atmel_init_property(atmel_port, pdev);
@@ -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;
}