1 files changed, 72 insertions, 1 deletions

diff --git a/drivers/tty/serial/mcf.c b/drivers/tty/serial/mcf.c
index fcd56ab6053f..e956377a38fe 100644
--- a/drivers/tty/serial/mcf.c
+++ b/drivers/tty/serial/mcf.c
@@ -23,6 +23,7 @@
 #include <linux/serial.h>
 #include <linux/serial_core.h>
 #include <linux/io.h>
+#include <linux/uaccess.h>
 #include <asm/coldfire.h>
 #include <asm/mcfsim.h>
 #include <asm/mcfuart.h>
@@ -55,6 +56,7 @@ struct mcf_uart {
         struct uart_port        port;
         unsigned int            sigs;           /* Local copy of line sigs */
         unsigned char           imr;            /* Local IMR mirror */
+        struct serial_rs485     rs485;          /* RS485 settings */
 };
 
 /****************************************************************************/
@@ -101,6 +103,12 @@ static void mcf_start_tx(struct uart_port *port)
 {
         struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
 
+        if (pp->rs485.flags & SER_RS485_ENABLED) {
+                /* Enable Transmitter */
+                writeb(MCFUART_UCR_TXENABLE, port->membase + MCFUART_UCR);
+                /* Manually assert RTS */
+                writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
+        }
         pp->imr |= MCFUART_UIR_TXREADY;
         writeb(pp->imr, port->membase + MCFUART_UIMR);
 }
@@ -196,6 +204,7 @@ static void mcf_shutdown(struct uart_port *port)
 static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
         struct ktermios *old)
 {
+        struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
         unsigned long flags;
         unsigned int baud, baudclk;
 #if defined(CONFIG_M5272)
@@ -248,6 +257,11 @@ static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
                 mr2 |= MCFUART_MR2_TXCTS;
         }
 
+        if (pp->rs485.flags & SER_RS485_ENABLED) {
+                dev_dbg(port->dev, "Setting UART to RS485\n");
+                mr2 |= MCFUART_MR2_TXRTS;
+        }
+
         spin_lock_irqsave(&port->lock, flags);
         uart_update_timeout(port, termios->c_cflag, baud);
         writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
@@ -310,7 +324,7 @@ static void mcf_rx_chars(struct mcf_uart *pp)
                 uart_insert_char(port, status, MCFUART_USR_RXOVERRUN, ch, flag);
         }
 
-        tty_flip_buffer_push(port->state->port.tty);
+        tty_flip_buffer_push(&port->state->port);
 }
 
 /****************************************************************************/
@@ -342,6 +356,10 @@ static void mcf_tx_chars(struct mcf_uart *pp)
         if (xmit->head == xmit->tail) {
                 pp->imr &= ~MCFUART_UIR_TXREADY;
                 writeb(pp->imr, port->membase + MCFUART_UIMR);
+                /* Disable TX to negate RTS automatically */
+                if (pp->rs485.flags & SER_RS485_ENABLED)
+                        writeb(MCFUART_UCR_TXDISABLE,
+                                port->membase + MCFUART_UCR);
         }
 }
 
@@ -418,6 +436,58 @@ static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser)
 
 /****************************************************************************/
 
+/* Enable or disable the RS485 support */
+static void mcf_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
+{
+        struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+        unsigned long flags;
+        unsigned char mr1, mr2;
+
+        spin_lock_irqsave(&port->lock, flags);
+        /* Get mode registers */
+        mr1 = readb(port->membase + MCFUART_UMR);
+        mr2 = readb(port->membase + MCFUART_UMR);
+        if (rs485->flags & SER_RS485_ENABLED) {
+                dev_dbg(port->dev, "Setting UART to RS485\n");
+                /* Automatically negate RTS after TX completes */
+                mr2 |= MCFUART_MR2_TXRTS;
+        } else {
+                dev_dbg(port->dev, "Setting UART to RS232\n");
+                mr2 &= ~MCFUART_MR2_TXRTS;
+        }
+        writeb(mr1, port->membase + MCFUART_UMR);
+        writeb(mr2, port->membase + MCFUART_UMR);
+        pp->rs485 = *rs485;
+        spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int mcf_ioctl(struct uart_port *port, unsigned int cmd,
+                unsigned long arg)
+{
+        switch (cmd) {
+        case TIOCSRS485: {
+                struct serial_rs485 rs485;
+                if (copy_from_user(&rs485, (struct serial_rs485 *)arg,
+                                sizeof(struct serial_rs485)))
+                        return -EFAULT;
+                mcf_config_rs485(port, &rs485);
+                break;
+        }
+        case TIOCGRS485: {
+                struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+                if (copy_to_user((struct serial_rs485 *)arg, &pp->rs485,
+                                sizeof(struct serial_rs485)))
+                        return -EFAULT;
+                break;
+        }
+        default:
+                return -ENOIOCTLCMD;
+        }
+        return 0;
+}
+
+/****************************************************************************/
+
 /*
  *      Define the basic serial functions we support.
  */
@@ -438,6 +508,7 @@ static const struct uart_ops mcf_uart_ops = {
         .release_port   = mcf_release_port,
         .config_port    = mcf_config_port,
         .verify_port    = mcf_verify_port,
+        .ioctl          = mcf_ioctl,
 };
 
 static struct mcf_uart mcf_ports[4];