tty: serial: msm: Support big-endian CPUs

To support big-endian CPUs use the string versions of the io
read/write macros on the TX/RX fifos and the non-raw variants of
the readl/writel macros throughout. This way we don't byteswap
the characters coming from the fifos but we properly deal with
the little-endian nature of the serial hardware while controlling
it.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 20 insertions, 12 deletions

diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index 90feee190f2a..c549110509bb 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -125,14 +125,14 @@ static void handle_rx_dm(struct uart_port *port, unsigned int misr)
         port->icount.rx += count;
 
         while (count > 0) {
-                unsigned int c;
+                unsigned char buf[4];
 
                 sr = msm_read(port, UART_SR);
                 if ((sr & UART_SR_RX_READY) == 0) {
                         msm_port->old_snap_state -= count;
                         break;
                 }
-                c = msm_read(port, UARTDM_RF);
+                ioread32_rep(port->membase + UARTDM_RF, buf, 1);
                 if (sr & UART_SR_RX_BREAK) {
                         port->icount.brk++;
                         if (uart_handle_break(port))
@@ -141,8 +141,7 @@ static void handle_rx_dm(struct uart_port *port, unsigned int misr)
                         port->icount.frame++;
 
                 /* TODO: handle sysrq */
-                tty_insert_flip_string(tport, (char *)&c,
-                                       (count > 4) ? 4 : count);
+                tty_insert_flip_string(tport, buf, min(count, 4));
                 count -= 4;
         }
 
@@ -219,6 +218,12 @@ static void handle_tx(struct uart_port *port)
         struct msm_port *msm_port = UART_TO_MSM(port);
         unsigned int tx_count, num_chars;
         unsigned int tf_pointer = 0;
+        void __iomem *tf;
+
+        if (msm_port->is_uartdm)
+                tf = port->membase + UARTDM_TF;
+        else
+                tf = port->membase + UART_TF;
 
         tx_count = uart_circ_chars_pending(xmit);
         tx_count = min3(tx_count, (unsigned int)UART_XMIT_SIZE - xmit->tail,
@@ -228,8 +233,7 @@ static void handle_tx(struct uart_port *port)
                 if (msm_port->is_uartdm)
                         reset_dm_count(port, tx_count + 1);
 
-                msm_write(port, port->x_char,
-                          msm_port->is_uartdm ? UARTDM_TF : UART_TF);
+                iowrite8_rep(tf, &port->x_char, 1);
                 port->icount.tx++;
                 port->x_char = 0;
         } else if (tx_count && msm_port->is_uartdm) {
@@ -239,7 +243,6 @@ static void handle_tx(struct uart_port *port)
         while (tf_pointer < tx_count) {
                 int i;
                 char buf[4] = { 0 };
-                unsigned int *bf = (unsigned int *)&buf;
 
                 if (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
                         break;
@@ -255,7 +258,7 @@ static void handle_tx(struct uart_port *port)
                         port->icount.tx++;
                 }
 
-                msm_write(port, *bf, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
+                iowrite32_rep(tf, buf, 1);
                 xmit->tail = (xmit->tail + num_chars) & (UART_XMIT_SIZE - 1);
                 tf_pointer += num_chars;
         }
@@ -861,12 +864,18 @@ static void msm_console_write(struct console *co, const char *s,
         struct msm_port *msm_port;
         int num_newlines = 0;
         bool replaced = false;
+        void __iomem *tf;
 
         BUG_ON(co->index < 0 || co->index >= UART_NR);
 
         port = get_port_from_line(co->index);
         msm_port = UART_TO_MSM(port);
 
+        if (msm_port->is_uartdm)
+                tf = port->membase + UARTDM_TF;
+        else
+                tf = port->membase + UART_TF;
+
         /* Account for newlines that will get a carriage return added */
         for (i = 0; i < count; i++)
                 if (s[i] == '\n')
@@ -882,7 +891,6 @@ static void msm_console_write(struct console *co, const char *s,
                 int j;
                 unsigned int num_chars;
                 char buf[4] = { 0 };
-                unsigned int *bf = (unsigned int *)&buf;
 
                 if (msm_port->is_uartdm)
                         num_chars = min(count - i, (unsigned int)sizeof(buf));
@@ -907,7 +915,7 @@ static void msm_console_write(struct console *co, const char *s,
                 while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
                         cpu_relax();
 
-                msm_write(port, *bf, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
+                iowrite32_rep(tf, buf, 1);
                 i += num_chars;
         }
         spin_unlock(&port->lock);
diff --git a/drivers/tty/serial/msm_serial.h b/drivers/tty/serial/msm_serial.h
index d98d45efdf86..73d3abe71e79 100644
--- a/drivers/tty/serial/msm_serial.h
+++ b/drivers/tty/serial/msm_serial.h
@@ -126,13 +126,13 @@
 static inline
 void msm_write(struct uart_port *port, unsigned int val, unsigned int off)
 {
-        __raw_writel(val, port->membase + off);
+        writel_relaxed(val, port->membase + off);
 }
 
 static inline
 unsigned int msm_read(struct uart_port *port, unsigned int off)
 {
-        return __raw_readl(port->membase + off);
+        return readl_relaxed(port->membase + off);
 }
 
 /*