serial: max310x: Add the loopback mode support

This patch replaces loopback mode support from platform data to
dynamic setup with TIOCMSET ioctl.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 18 insertions, 8 deletions

diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 1fb3895a0a3a..3c93814b1648 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -283,6 +283,7 @@ struct max310x_devtype {
 struct max310x_one {
         struct uart_port        port;
         struct work_struct      tx_work;
+        struct work_struct      md_work;
 };
 
 struct max310x_port {
@@ -790,11 +791,21 @@ static unsigned int max310x_get_mctrl(struct uart_port *port)
         return TIOCM_DSR | TIOCM_CAR;
 }
 
+static void max310x_md_proc(struct work_struct *ws)
+{
+        struct max310x_one *one = container_of(ws, struct max310x_one, md_work);
+
+        max310x_port_update(&one->port, MAX310X_MODE2_REG,
+                            MAX310X_MODE2_LOOPBACK_BIT,
+                            (one->port.mctrl & TIOCM_LOOP) ?
+                            MAX310X_MODE2_LOOPBACK_BIT : 0);
+}
+
 static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
-        /* DCD and DSR are not wired and CTS/RTS is hadnled automatically
-         * so do nothing
-         */
+        struct max310x_one *one = container_of(port, struct max310x_one, port);
+
+        schedule_work(&one->md_work);
 }
 
 static void max310x_break_ctl(struct uart_port *port, int break_state)
@@ -904,8 +915,6 @@ static int max310x_startup(struct uart_port *port)
 
         /* Configure MODE2 register */
         val = MAX310X_MODE2_RXEMPTINV_BIT;
-        if (s->pdata->uart_flags[line] & MAX310X_LOOPBACK)
-                val |= MAX310X_MODE2_LOOPBACK_BIT;
         if (s->pdata->uart_flags[line] & MAX310X_ECHO_SUPRESS)
                 val |= MAX310X_MODE2_ECHOSUPR_BIT;
 
@@ -1176,8 +1185,7 @@ static int max310x_probe(struct device *dev, int is_spi,
                 s->p[i].port.irq        = irq;
                 s->p[i].port.type       = PORT_MAX310X;
                 s->p[i].port.fifosize   = MAX310X_FIFO_SIZE;
-                s->p[i].port.flags      = UPF_SKIP_TEST | UPF_FIXED_TYPE |
-                                          UPF_LOW_LATENCY;
+                s->p[i].port.flags      = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
                 s->p[i].port.iotype     = UPIO_PORT;
                 s->p[i].port.iobase     = i * 0x20;
                 s->p[i].port.membase    = (void __iomem *)~0;
@@ -1193,6 +1201,8 @@ static int max310x_probe(struct device *dev, int is_spi,
                                     MAX310X_MODE1_IRQSEL_BIT);
                 /* Initialize queue for start TX */
                 INIT_WORK(&s->p[i].tx_work, max310x_wq_proc);
+                /* Initialize queue for changing mode */
+                INIT_WORK(&s->p[i].md_work, max310x_md_proc);
                 /* Register port */
                 uart_add_one_port(&s->uart, &s->p[i].port);
                 /* Go to suspend mode */
@@ -1244,6 +1254,7 @@ static int max310x_remove(struct device *dev)
 
         for (i = 0; i < s->uart.nr; i++) {
                 cancel_work_sync(&s->p[i].tx_work);
+                cancel_work_sync(&s->p[i].md_work);
                 uart_remove_one_port(&s->uart, &s->p[i].port);
                 s->devtype->power(&s->p[i].port, 0);
         }
diff --git a/include/linux/platform_data/max310x.h b/include/linux/platform_data/max310x.h
index 5f4b35d99c2e..9d5f69b2b57c 100644
--- a/include/linux/platform_data/max310x.h
+++ b/include/linux/platform_data/max310x.h
@@ -46,7 +46,6 @@ struct max310x_pdata {
 #define MAX310X_EXT_CLK         (0x00000001)    /* External clock enable */
         /* Flags global to UART port */
         const u8                uart_flags[MAX310X_MAX_UARTS];
-#define MAX310X_LOOPBACK        (0x00000001)    /* Loopback mode enable */
 #define MAX310X_ECHO_SUPRESS    (0x00000002)    /* Enable echo supress */
 #define MAX310X_AUTO_DIR_CTRL   (0x00000004)    /* Enable Auto direction
                                                  * control (RS-485)