ARM: 6157/2: PL011 TX/RX split of LCR for ST-Ericssons derivative

In the ST-Ericsson version of the PL011 the TX and RX have different
control registers.

Cc: Alessandro Rubini <rubini@unipv.it>
Signed-off-by: Marcin Mielczarczyk <marcin.mielczarczyk@tieto.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 50 insertions, 11 deletions

diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c
index eb4cb480b93e..5644cf2385bb 100644
--- a/drivers/serial/amba-pl011.c
+++ b/drivers/serial/amba-pl011.c
@@ -69,9 +69,11 @@
 struct uart_amba_port {
         struct uart_port        port;
         struct clk              *clk;
-        unsigned int            im;     /* interrupt mask */
+        unsigned int            im;             /* interrupt mask */
         unsigned int            old_status;
-        unsigned int            ifls;   /* vendor-specific */
+        unsigned int            ifls;           /* vendor-specific */
+        unsigned int            lcrh_tx;        /* vendor-specific */
+        unsigned int            lcrh_rx;        /* vendor-specific */
         bool                    autorts;
 };
 
@@ -79,16 +81,22 @@ struct uart_amba_port {
 struct vendor_data {
         unsigned int            ifls;
         unsigned int            fifosize;
+        unsigned int            lcrh_tx;
+        unsigned int            lcrh_rx;
 };
 
 static struct vendor_data vendor_arm = {
         .ifls                   = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
         .fifosize               = 16,
+        .lcrh_tx                = UART011_LCRH,
+        .lcrh_rx                = UART011_LCRH,
 };
 
 static struct vendor_data vendor_st = {
         .ifls                   = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF,
         .fifosize               = 64,
+        .lcrh_tx                = ST_UART011_LCRH_TX,
+        .lcrh_rx                = ST_UART011_LCRH_RX,
 };
 
 static void pl011_stop_tx(struct uart_port *port)
@@ -327,12 +335,12 @@ static void pl011_break_ctl(struct uart_port *port, int break_state)
         unsigned int lcr_h;
 
         spin_lock_irqsave(&uap->port.lock, flags);
-        lcr_h = readw(uap->port.membase + UART011_LCRH);
+        lcr_h = readw(uap->port.membase + uap->lcrh_tx);
         if (break_state == -1)
                 lcr_h |= UART01x_LCRH_BRK;
         else
                 lcr_h &= ~UART01x_LCRH_BRK;
-        writew(lcr_h, uap->port.membase + UART011_LCRH);
+        writew(lcr_h, uap->port.membase + uap->lcrh_tx);
         spin_unlock_irqrestore(&uap->port.lock, flags);
 }
 
@@ -393,7 +401,17 @@ static int pl011_startup(struct uart_port *port)
         writew(cr, uap->port.membase + UART011_CR);
         writew(0, uap->port.membase + UART011_FBRD);
         writew(1, uap->port.membase + UART011_IBRD);
-        writew(0, uap->port.membase + UART011_LCRH);
+        writew(0, uap->port.membase + uap->lcrh_rx);
+        if (uap->lcrh_tx != uap->lcrh_rx) {
+                int i;
+                /*
+                 * Wait 10 PCLKs before writing LCRH_TX register,
+                 * to get this delay write read only register 10 times
+                 */
+                for (i = 0; i < 10; ++i)
+                        writew(0xff, uap->port.membase + UART011_MIS);
+                writew(0, uap->port.membase + uap->lcrh_tx);
+        }
         writew(0, uap->port.membase + UART01x_DR);
         while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_BUSY)
                 barrier();
@@ -422,10 +440,19 @@ static int pl011_startup(struct uart_port *port)
         return retval;
 }
 
+static void pl011_shutdown_channel(struct uart_amba_port *uap,
+                                        unsigned int lcrh)
+{
+      unsigned long val;
+
+      val = readw(uap->port.membase + lcrh);
+      val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
+      writew(val, uap->port.membase + lcrh);
+}
+
 static void pl011_shutdown(struct uart_port *port)
 {
         struct uart_amba_port *uap = (struct uart_amba_port *)port;
-        unsigned long val;
 
         /*
          * disable all interrupts
@@ -450,9 +477,9 @@ static void pl011_shutdown(struct uart_port *port)
         /*
          * disable break condition and fifos
          */
-        val = readw(uap->port.membase + UART011_LCRH);
-        val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
-        writew(val, uap->port.membase + UART011_LCRH);
+        pl011_shutdown_channel(uap, uap->lcrh_rx);
+        if (uap->lcrh_rx != uap->lcrh_tx)
+                pl011_shutdown_channel(uap, uap->lcrh_tx);
 
         /*
          * Shut down the clock producer
@@ -561,7 +588,17 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
          * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
          * ----------^----------^----------^----------^-----
          */
-        writew(lcr_h, port->membase + UART011_LCRH);
+        writew(lcr_h, port->membase + uap->lcrh_rx);
+        if (uap->lcrh_rx != uap->lcrh_tx) {
+                int i;
+                /*
+                 * Wait 10 PCLKs before writing LCRH_TX register,
+                 * to get this delay write read only register 10 times
+                 */
+                for (i = 0; i < 10; ++i)
+                        writew(0xff, uap->port.membase + UART011_MIS);
+                writew(lcr_h, port->membase + uap->lcrh_tx);
+        }
         writew(old_cr, port->membase + UART011_CR);
 
         spin_unlock_irqrestore(&port->lock, flags);
@@ -688,7 +725,7 @@ pl011_console_get_options(struct uart_amba_port *uap, int *baud,
         if (readw(uap->port.membase + UART011_CR) & UART01x_CR_UARTEN) {
                 unsigned int lcr_h, ibrd, fbrd;
 
-                lcr_h = readw(uap->port.membase + UART011_LCRH);
+                lcr_h = readw(uap->port.membase + uap->lcrh_tx);
 
                 *parity = 'n';
                 if (lcr_h & UART01x_LCRH_PEN) {
@@ -800,6 +837,8 @@ static int pl011_probe(struct amba_device *dev, struct amba_id *id)
         }
 
         uap->ifls = vendor->ifls;
+        uap->lcrh_rx = vendor->lcrh_rx;
+        uap->lcrh_tx = vendor->lcrh_tx;
         uap->port.dev = &dev->dev;
         uap->port.mapbase = dev->res.start;
         uap->port.membase = base;