2014-08-10 21:33 GMT+02:00 Peter Hurley [off-list ref]:

Hi Richard,

Hi !
Sorry for the delay !

On 05/13/2014 02:20 PM, Richard Genoud wrote:

quoted

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

Signed-off-by: Richard Genoud <redacted>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Nicolas Ferre <redacted>
---
 drivers/tty/serial/atmel_serial.c |  125 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 122 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 43ca659..3fceae0 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;

Where are these gpio irqs disabled if !UART_ENABLE_MS()?

They are disabled in atmel_shutdown()/atmel_free_gpio_irq().
Like the doc says in Documentation/serial/driver
  enable_ms(port)
    Enable the modem status interrupts.

    This method may be called multiple times.  Modem status
    interrupts should be disabled when the shutdown method is
    called.

Regards,
Richard.