1 files changed, 33 insertions, 18 deletions

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 57d6b29c039c..4dc41408ecb7 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -59,6 +59,7 @@
 
 /* SCR register bitmasks */
 #define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK               (1 << 7)
+#define OMAP_UART_SCR_TX_TRIG_GRANU1_MASK               (1 << 6)
 #define OMAP_UART_SCR_TX_EMPTY                  (1 << 3)
 
 /* FCR register bitmasks */
@@ -232,24 +233,42 @@ static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable)
 }
 
 /*
+ * serial_omap_baud_is_mode16 - check if baud rate is MODE16X
+ * @port: uart port info
+ * @baud: baudrate for which mode needs to be determined
+ *
+ * Returns true if baud rate is MODE16X and false if MODE13X
+ * Original table in OMAP TRM named "UART Mode Baud Rates, Divisor Values,
+ * and Error Rates" determines modes not for all common baud rates.
+ * E.g. for 1000000 baud rate mode must be 16x, but according to that
+ * table it's determined as 13x.
+ */
+static bool
+serial_omap_baud_is_mode16(struct uart_port *port, unsigned int baud)
+{
+        unsigned int n13 = port->uartclk / (13 * 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)
+                baudAbsDiff13 = -baudAbsDiff13;
+        if(baudAbsDiff16 < 0)
+                baudAbsDiff16 = -baudAbsDiff16;
+
+        return (baudAbsDiff13 > baudAbsDiff16);
+}
+
+/*
  * serial_omap_get_divisor - calculate divisor value
  * @port: uart port info
  * @baud: baudrate for which divisor needs to be calculated.
- *
- * We have written our own function to get the divisor so as to support
- * 13x mode. 3Mbps Baudrate as an different divisor.
- * Reference OMAP TRM Chapter 17:
- * Table 17-1. UART Mode Baud Rates, Divisor Values, and Error Rates
- * referring to oversampling - divisor value
- * baudrate 460,800 to 3,686,400 all have divisor 13
- * except 3,000,000 which has divisor value 16
  */
 static unsigned int
 serial_omap_get_divisor(struct uart_port *port, unsigned int baud)
 {
         unsigned int divisor;
 
-        if (baud > OMAP_MODE13X_SPEED && baud != 3000000)
+        if (!serial_omap_baud_is_mode16(port, baud))
                 divisor = 13;
         else
                 divisor = 16;
@@ -302,9 +321,6 @@ static void transmit_chars(struct uart_omap_port *up, unsigned int lsr)
         struct circ_buf *xmit = &up->port.state->xmit;
         int count;
 
-        if (!(lsr & UART_LSR_THRE))
-                return;
-
         if (up->port.x_char) {
                 serial_out(up, UART_TX, up->port.x_char);
                 up->port.icount.tx++;
@@ -483,7 +499,6 @@ static void serial_omap_rdi(struct uart_omap_port *up, unsigned int lsr)
 static irqreturn_t serial_omap_irq(int irq, void *dev_id)
 {
         struct uart_omap_port *up = dev_id;
-        struct tty_struct *tty = up->port.state->port.tty;
         unsigned int iir, lsr;
         unsigned int type;
         irqreturn_t ret = IRQ_NONE;
@@ -530,7 +545,7 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
 
         spin_unlock(&up->port.lock);
 
-        tty_flip_buffer_push(tty);
+        tty_flip_buffer_push(&up->port.state->port);
 
         pm_runtime_mark_last_busy(up->dev);
         pm_runtime_put_autosuspend(up->dev);
@@ -776,6 +791,8 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
                 cval |= UART_LCR_PARITY;
         if (!(termios->c_cflag & PARODD))
                 cval |= UART_LCR_EPAR;
+        if (termios->c_cflag & CMSPAR)
+                cval |= UART_LCR_SPAR;
 
         /*
          * Ask the core to calculate the divisor for us.
@@ -845,7 +862,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
         serial_out(up, UART_IER, up->ier);
         serial_out(up, UART_LCR, cval);         /* reset DLAB */
         up->lcr = cval;
-        up->scr = OMAP_UART_SCR_TX_EMPTY;
+        up->scr = 0;
 
         /* FIFOs and DMA Settings */
 
@@ -869,8 +886,6 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
         serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
         /* FIFO ENABLE, DMA MODE */
 
-        up->scr |= OMAP_UART_SCR_RX_TRIG_GRANU1_MASK;
-
         /* Set receive FIFO threshold to 16 characters and
          * transmit FIFO threshold to 16 spaces
          */
@@ -915,7 +930,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
         serial_out(up, UART_EFR, up->efr);
         serial_out(up, UART_LCR, cval);
 
-        if (baud > 230400 && baud != 3000000)
+        if (!serial_omap_baud_is_mode16(port, baud))
                 up->mdr1 = UART_OMAP_MDR1_13X_MODE;
         else
                 up->mdr1 = UART_OMAP_MDR1_16X_MODE;