1 files changed, 97 insertions, 44 deletions

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 816d1a23f9d0..fa511ebab67c 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -39,6 +39,7 @@
 #include <linux/irq.h>
 #include <linux/pm_runtime.h>
 #include <linux/of.h>
+#include <linux/of_irq.h>
 #include <linux/gpio.h>
 #include <linux/of_gpio.h>
 #include <linux/platform_data/serial-omap.h>
@@ -134,6 +135,7 @@ struct uart_omap_port {
         struct uart_port        port;
         struct uart_omap_dma    uart_dma;
         struct device           *dev;
+        int                     wakeirq;
 
         unsigned char           ier;
         unsigned char           lcr;
@@ -175,7 +177,7 @@ struct uart_omap_port {
         bool                    is_suspending;
 };
 
-#define to_uart_omap_port(p)    ((container_of((p), struct uart_omap_port, port)))
+#define to_uart_omap_port(p) ((container_of((p), struct uart_omap_port, port)))
 
 static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
 
@@ -214,10 +216,23 @@ static int serial_omap_get_context_loss_count(struct uart_omap_port *up)
         return pdata->get_context_loss_count(up->dev);
 }
 
+static inline void serial_omap_enable_wakeirq(struct uart_omap_port *up,
+                                       bool enable)
+{
+        if (!up->wakeirq)
+                return;
+
+        if (enable)
+                enable_irq(up->wakeirq);
+        else
+                disable_irq(up->wakeirq);
+}
+
 static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable)
 {
         struct omap_uart_port_info *pdata = dev_get_platdata(up->dev);
 
+        serial_omap_enable_wakeirq(up, enable);
         if (!pdata || !pdata->enable_wakeup)
                 return;
 
@@ -242,12 +257,12 @@ serial_omap_baud_is_mode16(struct uart_port *port, unsigned int baud)
         unsigned int n16 = port->uartclk / (16 * baud);
         int baudAbsDiff13 = baud - (port->uartclk / (13 * n13));
         int baudAbsDiff16 = baud - (port->uartclk / (16 * n16));
-        if(baudAbsDiff13 < 0)
+        if (baudAbsDiff13 < 0)
                 baudAbsDiff13 = -baudAbsDiff13;
-        if(baudAbsDiff16 < 0)
+        if (baudAbsDiff16 < 0)
                 baudAbsDiff16 = -baudAbsDiff16;
 
-        return (baudAbsDiff13 > baudAbsDiff16);
+        return (baudAbsDiff13 >= baudAbsDiff16);
 }
 
 /*
@@ -258,13 +273,13 @@ serial_omap_baud_is_mode16(struct uart_port *port, unsigned int baud)
 static unsigned int
 serial_omap_get_divisor(struct uart_port *port, unsigned int baud)
 {
-        unsigned int divisor;
+        unsigned int mode;
 
         if (!serial_omap_baud_is_mode16(port, baud))
-                divisor = 13;
+                mode = 13;
         else
-                divisor = 16;
-        return port->uartclk/(baud * divisor);
+                mode = 16;
+        return port->uartclk/(mode * baud);
 }
 
 static void serial_omap_enable_ms(struct uart_port *port)
@@ -283,28 +298,40 @@ static void serial_omap_enable_ms(struct uart_port *port)
 static void serial_omap_stop_tx(struct uart_port *port)
 {
         struct uart_omap_port *up = to_uart_omap_port(port);
-        struct circ_buf *xmit = &up->port.state->xmit;
         int res;
 
         pm_runtime_get_sync(up->dev);
 
-        /* handle rs485 */
+        /* Handle RS-485 */
         if (up->rs485.flags & SER_RS485_ENABLED) {
-                /* do nothing if current tx not yet completed */
-                res = serial_in(up, UART_LSR) & UART_LSR_TEMT;
-                if (!res)
-                        return;
-
-                /* if there's no more data to send, turn off rts */
-                if (uart_circ_empty(xmit)) {
-                        /* if rts not already disabled */
+                if (up->scr & OMAP_UART_SCR_TX_EMPTY) {
+                        /* THR interrupt is fired when both TX FIFO and TX
+                         * shift register are empty. This means there's nothing
+                         * left to transmit now, so make sure the THR interrupt
+                         * is fired when TX FIFO is below the trigger level,
+                         * disable THR interrupts and toggle the RS-485 GPIO
+                         * data direction pin if needed.
+                         */
+                        up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
+                        serial_out(up, UART_OMAP_SCR, up->scr);
                         res = (up->rs485.flags & SER_RS485_RTS_AFTER_SEND) ? 1 : 0;
                         if (gpio_get_value(up->rts_gpio) != res) {
-                                if (up->rs485.delay_rts_after_send > 0) {
+                                if (up->rs485.delay_rts_after_send > 0)
                                         mdelay(up->rs485.delay_rts_after_send);
-                                }
                                 gpio_set_value(up->rts_gpio, res);
                         }
+                } else {
+                        /* We're asked to stop, but there's still stuff in the
+                         * UART FIFO, so make sure the THR interrupt is fired
+                         * when both TX FIFO and TX shift register are empty.
+                         * The next THR interrupt (if no transmission is started
+                         * in the meantime) will indicate the end of a
+                         * transmission. Therefore we _don't_ disable THR
+                         * interrupts in this situation.
+                         */
+                        up->scr |= OMAP_UART_SCR_TX_EMPTY;
+                        serial_out(up, UART_OMAP_SCR, up->scr);
+                        return;
                 }
         }
 
@@ -384,15 +411,18 @@ static void serial_omap_start_tx(struct uart_port *port)
 
         pm_runtime_get_sync(up->dev);
 
-        /* handle rs485 */
+        /* Handle RS-485 */
         if (up->rs485.flags & SER_RS485_ENABLED) {
+                /* Fire THR interrupts when FIFO is below trigger level */
+                up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
+                serial_out(up, UART_OMAP_SCR, up->scr);
+
                 /* if rts not already enabled */
                 res = (up->rs485.flags & SER_RS485_RTS_ON_SEND) ? 1 : 0;
                 if (gpio_get_value(up->rts_gpio) != res) {
                         gpio_set_value(up->rts_gpio, res);
-                        if (up->rs485.delay_rts_before_send > 0) {
+                        if (up->rs485.delay_rts_before_send > 0)
                                 mdelay(up->rs485.delay_rts_before_send);
-                        }
                 }
         }
 
@@ -699,6 +729,20 @@ static int serial_omap_startup(struct uart_port *port)
         if (retval)
                 return retval;
 
+        /* Optional wake-up IRQ */
+        if (up->wakeirq) {
+                retval = request_irq(up->wakeirq, serial_omap_irq,
+                                     up->port.irqflags, up->name, up);
+                if (retval) {
+                        free_irq(up->port.irq, up);
+                        return retval;
+                }
+                disable_irq(up->wakeirq);
+        } else {
+                dev_info(up->port.dev, "no wakeirq for uart%d\n",
+                         up->port.line);
+        }
+
         dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->port.line);
 
         pm_runtime_get_sync(up->dev);
@@ -787,6 +831,8 @@ static void serial_omap_shutdown(struct uart_port *port)
         pm_runtime_mark_last_busy(up->dev);
         pm_runtime_put_autosuspend(up->dev);
         free_irq(up->port.irq, up);
+        if (up->wakeirq)
+                free_irq(up->wakeirq, up);
 }
 
 static void serial_omap_uart_qos_work(struct work_struct *work)
@@ -938,7 +984,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
          */
 
         /* Set receive FIFO threshold to 16 characters and
-         * transmit FIFO threshold to 16 spaces
+         * transmit FIFO threshold to 32 spaces
          */
         up->fcr &= ~OMAP_UART_FCR_RX_FIFO_TRIG_MASK;
         up->fcr &= ~OMAP_UART_FCR_TX_FIFO_TRIG_MASK;
@@ -1060,15 +1106,6 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
         dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->port.line);
 }
 
-static int serial_omap_set_wake(struct uart_port *port, unsigned int state)
-{
-        struct uart_omap_port *up = to_uart_omap_port(port);
-
-        serial_omap_enable_wakeup(up, state);
-
-        return 0;
-}
-
 static void
 serial_omap_pm(struct uart_port *port, unsigned int state,
                unsigned int oldstate)
@@ -1353,6 +1390,15 @@ serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
         up->ier = mode;
         serial_out(up, UART_IER, up->ier);
 
+        /* If RS-485 is disabled, make sure the THR interrupt is fired when
+         * TX FIFO is below the trigger level.
+         */
+        if (!(up->rs485.flags & SER_RS485_ENABLED) &&
+            (up->scr & OMAP_UART_SCR_TX_EMPTY)) {
+                up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
+                serial_out(up, UART_OMAP_SCR, up->scr);
+        }
+
         spin_unlock_irqrestore(&up->port.lock, flags);
         pm_runtime_mark_last_busy(up->dev);
         pm_runtime_put_autosuspend(up->dev);
@@ -1401,7 +1447,6 @@ static struct uart_ops serial_omap_pops = {
         .shutdown       = serial_omap_shutdown,
         .set_termios    = serial_omap_set_termios,
         .pm             = serial_omap_pm,
-        .set_wake       = serial_omap_set_wake,
         .type           = serial_omap_type,
         .release_port   = serial_omap_release_port,
         .request_port   = serial_omap_request_port,
@@ -1582,11 +1627,23 @@ static int serial_omap_probe(struct platform_device *pdev)
         struct uart_omap_port   *up;
         struct resource         *mem, *irq;
         struct omap_uart_port_info *omap_up_info = dev_get_platdata(&pdev->dev);
-        int ret;
+        int ret, uartirq = 0, wakeirq = 0;
 
+        /* The optional wakeirq may be specified in the board dts file */
         if (pdev->dev.of_node) {
+                uartirq = irq_of_parse_and_map(pdev->dev.of_node, 0);
+                if (!uartirq)
+                        return -EPROBE_DEFER;
+                wakeirq = irq_of_parse_and_map(pdev->dev.of_node, 1);
                 omap_up_info = of_get_uart_port_info(&pdev->dev);
                 pdev->dev.platform_data = omap_up_info;
+        } else {
+                irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+                if (!irq) {
+                        dev_err(&pdev->dev, "no irq resource?\n");
+                        return -ENODEV;
+                }
+                uartirq = irq->start;
         }
 
         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1595,12 +1652,6 @@ static int serial_omap_probe(struct platform_device *pdev)
                 return -ENODEV;
         }
 
-        irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-        if (!irq) {
-                dev_err(&pdev->dev, "no irq resource?\n");
-                return -ENODEV;
-        }
-
         if (!devm_request_mem_region(&pdev->dev, mem->start, resource_size(mem),
                                 pdev->dev.driver->name)) {
                 dev_err(&pdev->dev, "memory region already claimed\n");
@@ -1634,7 +1685,8 @@ static int serial_omap_probe(struct platform_device *pdev)
         up->port.dev = &pdev->dev;
         up->port.type = PORT_OMAP;
         up->port.iotype = UPIO_MEM;
-        up->port.irq = irq->start;
+        up->port.irq = uartirq;
+        up->wakeirq = wakeirq;
 
         up->port.regshift = 2;
         up->port.fifosize = 64;
@@ -1670,8 +1722,9 @@ static int serial_omap_probe(struct platform_device *pdev)
         up->port.uartclk = omap_up_info->uartclk;
         if (!up->port.uartclk) {
                 up->port.uartclk = DEFAULT_CLK_SPEED;
-                dev_warn(&pdev->dev, "No clock speed specified: using default:"
-                                                "%d\n", DEFAULT_CLK_SPEED);
+                dev_warn(&pdev->dev,
+                         "No clock speed specified: using default: %d\n",
+                         DEFAULT_CLK_SPEED);
         }
 
         up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;