serial/arc-uart: switch to devicetree based probing

* DT binding for arc-uart
* With alll the bits in place we can now use DT probing.

Note that there's a bit of kludge right now because earlyprintk portion
of driver can't use the DT infrastrcuture to get resoures/plat_data.
This requires some infrastructre changes to of_flat_ framework

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Rob Landley <rob@landley.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/devicetree/bindings/tty/serial/arc-uart.txt b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
new file mode 100644 (file)
index 0000000..c3bd8f9
--- /dev/null
+++ b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
@@ -0,0 +1,26 @@
+* Synopsys ARC UART : Non standard UART used in some of the ARC FPGA boards
+
+Required properties:
+- compatible           : "snps,arc-uart"
+- reg                  : offset and length of the register set for the device.
+- interrupts           : device interrupt
+- clock-frequency      : the input clock frequency for the UART
+- baud                 : baud rate for UART
+
+e.g.
+
+arcuart0: serial@c0fc1000 {
+       compatible = "snps,arc-uart";
+       reg = <0xc0fc1000 0x100>;
+       interrupts = <5>;
+       clock-frequency = <80000000>;
+       baud = <115200>;
+       status = "okay";
+};
+
+Note: Each port should have an alias correctly numbered in "aliases" node.
+
+e.g.
+aliases {
+       serial0 = &arcuart0;
+};

diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
index 2db64105677b1024b8e05889a93972d57078b1d9..b4686010431284846df5d443b9257b237b764862 100644 (file)
--- a/drivers/tty/serial/arc_uart.c
+++ b/drivers/tty/serial/arc_uart.c
@@ -37,6 +37,8 @@
 #include <linux/tty_flip.h>
 #include <linux/serial_core.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
 
 /*************************************
  * ARC UART Hardware Specs
@@ -537,8 +539,26 @@ arc_uart_init_one(struct platform_device *pdev, int dev_id)
                return -ENODEV;
 
        uart->is_emulated = !!plat_data[0];     /* workaround ISS bug */
-       uart->port.uartclk = plat_data[1];
-       uart->baud = plat_data[2];
+
+       if (is_early_platform_device(pdev)) {
+               uart->port.uartclk = plat_data[1];
+               uart->baud = plat_data[2];
+       } else {
+               struct device_node *np = pdev->dev.of_node;
+               u32 val;
+
+               if (of_property_read_u32(np, "clock-frequency", &val)) {
+                       dev_err(&pdev->dev, "clock-frequency property NOTset\n");
+                       return -EINVAL;
+               }
+               uart->port.uartclk = val;
+
+               if (of_property_read_u32(np, "baud", &val)) {
+                       dev_err(&pdev->dev, "baud property NOT set\n");
+                       return -EINVAL;
+               }
+               uart->baud = val;
+       }
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
@@ -673,8 +693,18 @@ static int __init arc_serial_probe_earlyprintk(struct platform_device *pdev)
 static int arc_serial_probe(struct platform_device *pdev)
 {
        int rc, dev_id;
+       struct device_node *np = pdev->dev.of_node;
+
+       /* no device tree device */
+       if (!np)
+               return -ENODEV;
+
+       dev_id = of_alias_get_id(np, "serial");
+       if (dev_id < 0) {
+               dev_err(&pdev->dev, "failed to get alias id: %d\n", dev_id);
+               return dev_id;
+       }
 
-       dev_id = pdev->id < 0 ? 0 : pdev->id;
        rc = arc_uart_init_one(pdev, dev_id);
        if (rc)
                return rc;
@@ -689,12 +719,19 @@ static int arc_serial_remove(struct platform_device *pdev)
        return 0;
 }
 
+static const struct of_device_id arc_uart_dt_ids[] = {
+       { .compatible = "snps,arc-uart" },
+       { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, arc_uart_dt_ids);
+
 static struct platform_driver arc_platform_driver = {
        .probe = arc_serial_probe,
        .remove = arc_serial_remove,
        .driver = {
                .name = DRIVER_NAME,
                .owner = THIS_MODULE,
+               .of_match_table  = arc_uart_dt_ids,
         },
 };