msm_serial: Add devicetree support

Add devicetree support to the msm_serial driver.  Clocks are still
queried by direct name from the driver until device tree clock support
is implemented.

Change-Id: Ia6b2ddfcf1e5dc3bd25dd502662f971202e6d56f
Signed-off-by: David Brown <davidb@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 41 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/tty/serial/msm_serial.txt b/Documentation/devicetree/bindings/tty/serial/msm_serial.txt
new file mode 100644
index 000000000000..aef383eb8876
--- /dev/null
+++ b/Documentation/devicetree/bindings/tty/serial/msm_serial.txt
@@ -0,0 +1,27 @@
+* Qualcomm MSM UART
+
+Required properties:
+- compatible :
+        - "qcom,msm-uart", and one of "qcom,msm-hsuart" or
+          "qcom,msm-lsuart".
+- reg : offset and length of the register set for the device
+        for the hsuart operating in compatible mode, there should be a
+        second pair describing the gsbi registers.
+- interrupts : should contain the uart interrupt.
+
+There are two different UART blocks used in MSM devices,
+"qcom,msm-hsuart" and "qcom,msm-lsuart".  The msm-serial driver is
+able to handle both of these, and matches against the "qcom,msm-uart"
+as the compatibility.
+
+The registers for the "qcom,msm-hsuart" device need to specify both
+register blocks, even for the common driver.
+
+Example:
+
+        uart@19c400000 {
+                compatible = "qcom,msm-hsuart", "qcom,msm-uart";
+                reg = <0x19c40000 0x1000>,
+                      <0x19c00000 0x1000>;
+                interrupts = <195>;
+        };
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index d9863b2c2bc8..776790272454 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -19,6 +19,7 @@
 # define SUPPORT_SYSRQ
 #endif
 
+#include <linux/atomic.h>
 #include <linux/hrtimer.h>
 #include <linux/module.h>
 #include <linux/io.h>
@@ -33,6 +34,8 @@
 #include <linux/clk.h>
 #include <linux/platform_device.h>
 #include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include "msm_serial.h"
 
@@ -856,6 +859,8 @@ static struct uart_driver msm_uart_driver = {
         .cons = MSM_CONSOLE,
 };
 
+static atomic_t msm_uart_next_id = ATOMIC_INIT(0);
+
 static int __init msm_serial_probe(struct platform_device *pdev)
 {
         struct msm_port *msm_port;
@@ -863,6 +868,9 @@ static int __init msm_serial_probe(struct platform_device *pdev)
         struct uart_port *port;
         int irq;
 
+        if (pdev->id == -1)
+                pdev->id = atomic_inc_return(&msm_uart_next_id) - 1;
+
         if (unlikely(pdev->id < 0 || pdev->id >= UART_NR))
                 return -ENXIO;
 
@@ -920,11 +928,17 @@ static int __devexit msm_serial_remove(struct platform_device *pdev)
         return 0;
 }
 
+static struct of_device_id msm_match_table[] = {
+        { .compatible = "qcom,msm-uart" },
+        {}
+};
+
 static struct platform_driver msm_platform_driver = {
         .remove = msm_serial_remove,
         .driver = {
                 .name = "msm_serial",
                 .owner = THIS_MODULE,
+                .of_match_table = msm_match_table,
         },
 };