2 files changed, 48 insertions, 0 deletions

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index c5fb08cfbdb1..ab4db1dcc474 100644
--- 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 40b4cc4f8e1d..3231a43f6acf 100644
--- 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 */
 };