serial_core: Handle TIOC[GS]RS485 ioctls.

The following drivers: 8250_core, atmel_serial, max310x, mcf, omap-serial
and sci16is7xx implement code to handle RS485 ioctls.

In order to avoid code duplication, we implement a simple ioctl handler
on the serial_core layer.

This handler can be used by all the other drivers instead of duplicating
code.

Until this is the only RS485 ioctl handler, it will try first the
rs485_config callback and if it is not present it will call the driver
specific ioctl.

Reviewed-by: Alan Cox <alan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index c5fb08cfbdb1eb54fd71df51cb03520da83401ba..ab4db1dcc474a3cd8cca58e1ff23808984f0face 100644 (file)
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1152,6 +1152,39 @@ static int uart_get_icount(struct tty_struct *tty,
        return 0;
 }
 
+static int uart_get_rs485_config(struct uart_port *port,
+                        struct serial_rs485 __user *rs485)
+{
+       if (!port->rs485_config)
+               return -ENOIOCTLCMD;
+
+       if (copy_to_user(rs485, &port->rs485, sizeof(port->rs485)))
+               return -EFAULT;
+       return 0;
+}
+
+static int uart_set_rs485_config(struct uart_port *port,
+                        struct serial_rs485 __user *rs485_user)
+{
+       struct serial_rs485 rs485;
+       int ret;
+
+       if (!port->rs485_config)
+               return -ENOIOCTLCMD;
+
+       if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
+               return -EFAULT;
+
+       ret = port->rs485_config(port, &rs485);
+       if (ret)
+               return ret;
+
+       if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
+               return -EFAULT;
+
+       return 0;
+}
+
 /*
  * Called via sys_ioctl.  We can use spin_lock_irq() here.
  */
@@ -1223,6 +1256,18 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd,
         * protected against the tty being hung up.
         */
        switch (cmd) {
+       case TIOCGRS485:
+               ret = uart_get_rs485_config(state->uart_port, uarg);
+               break;
+
+       case TIOCSRS485:
+               ret = uart_set_rs485_config(state->uart_port, uarg);
+               break;
+       }
+       if (ret != -ENOIOCTLCMD)
+               goto out;
+
+       switch (cmd) {
        case TIOCSERGETLSR: /* Get line status register */
                ret = uart_get_lsr_info(tty, state, uarg);
                break;

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 40b4cc4f8e1de85cb185f09b61b7218610137dd6..3231a43f6acf09fc12f73e352e1aa3f7a2f1898d 100644 (file)
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -131,6 +131,8 @@ struct uart_port {
        void                    (*pm)(struct uart_port *, unsigned int state,
                                      unsigned int old);
        void                    (*handle_break)(struct uart_port *);
+       int                     (*rs485_config)(struct uart_port *,
+                                               struct serial_rs485 *rs485);
        unsigned int            irq;                    /* irq number */
        unsigned long           irqflags;               /* irq flags  */
        unsigned int            uartclk;                /* base uart clock */
@@ -231,6 +233,7 @@ struct uart_port {
        unsigned char           unused[2];
        struct attribute_group  *attr_group;            /* port specific attributes */
        const struct attribute_group **tty_groups;      /* all attributes (serial core use only) */
+       struct serial_rs485     rs485;
        void                    *private_data;          /* generic platform data pointer */
 };