can: c_can: Add device tree support to Bosch C_CAN/D_CAN controller

Add device tree support to C_CAN/D_CAN controller and usage details
are added to device tree documentation. Driver was tested on AM335x
EVM.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
For the of binding doc:
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

2 files changed, 87 insertions, 17 deletions

diff --git a/Documentation/devicetree/bindings/net/can/c_can.txt b/Documentation/devicetree/bindings/net/can/c_can.txt
new file mode 100644
index 00000000000..8f1ae81228e
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/can/c_can.txt
@@ -0,0 +1,49 @@
+Bosch C_CAN/D_CAN controller Device Tree Bindings
+-------------------------------------------------
+
+Required properties:
+- compatible            : Should be "bosch,c_can" for C_CAN controllers and
+                          "bosch,d_can" for D_CAN controllers.
+- reg                   : physical base address and size of the C_CAN/D_CAN
+                          registers map
+- interrupts            : property with a value describing the interrupt
+                          number
+
+Optional properties:
+- ti,hwmods             : Must be "d_can<n>" or "c_can<n>", n being the
+                          instance number
+
+Note: "ti,hwmods" field is used to fetch the base address and irq
+resources from TI, omap hwmod data base during device registration.
+Future plan is to migrate hwmod data base contents into device tree
+blob so that, all the required data will be used from device tree dts
+file.
+
+Example:
+
+Step1: SoC common .dtsi file
+
+        dcan1: d_can@481d0000 {
+                compatible = "bosch,d_can";
+                reg = <0x481d0000 0x2000>;
+                interrupts = <55>;
+                interrupt-parent = <&intc>;
+                status = "disabled";
+        };
+
+(or)
+
+        dcan1: d_can@481d0000 {
+                compatible = "bosch,d_can";
+                ti,hwmods = "d_can1";
+                reg = <0x481d0000 0x2000>;
+                interrupts = <55>;
+                interrupt-parent = <&intc>;
+                status = "disabled";
+        };
+
+Step 2: board specific .dts file
+
+        &dcan1 {
+                status = "okay";
+        };
diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index 5c46d1cc5cf..d0a66cf298b 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -30,6 +30,8 @@
 #include <linux/io.h>
 #include <linux/platform_device.h>
 #include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include <linux/can/dev.h>
 
@@ -65,17 +67,52 @@ static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
         writew(val, priv->base + 2 * priv->regs[index]);
 }
 
+static struct platform_device_id c_can_id_table[] = {
+        [BOSCH_C_CAN_PLATFORM] = {
+                .name = KBUILD_MODNAME,
+                .driver_data = BOSCH_C_CAN,
+        },
+        [BOSCH_C_CAN] = {
+                .name = "c_can",
+                .driver_data = BOSCH_C_CAN,
+        },
+        [BOSCH_D_CAN] = {
+                .name = "d_can",
+                .driver_data = BOSCH_D_CAN,
+        }, {
+        }
+};
+
+static const struct of_device_id c_can_of_table[] = {
+        { .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] },
+        { .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] },
+        { /* sentinel */ },
+};
+
 static int __devinit c_can_plat_probe(struct platform_device *pdev)
 {
         int ret;
         void __iomem *addr;
         struct net_device *dev;
         struct c_can_priv *priv;
+        const struct of_device_id *match;
         const struct platform_device_id *id;
         struct resource *mem;
         int irq;
         struct clk *clk;
 
+        if (pdev->dev.of_node) {
+                match = of_match_device(c_can_of_table, &pdev->dev);
+                if (!match) {
+                        dev_err(&pdev->dev, "Failed to find matching dt id\n");
+                        ret = -EINVAL;
+                        goto exit;
+                }
+                id = match->data;
+        } else {
+                id = platform_get_device_id(pdev);
+        }
+
         /* get the appropriate clk */
         clk = clk_get(&pdev->dev, NULL);
         if (IS_ERR(clk)) {
@@ -114,7 +151,6 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
         }
 
         priv = netdev_priv(dev);
-        id = platform_get_device_id(pdev);
         switch (id->driver_data) {
         case BOSCH_C_CAN:
                 priv->regs = reg_map_c_can;
@@ -195,26 +231,11 @@ static int __devexit c_can_plat_remove(struct platform_device *pdev)
         return 0;
 }
 
-static const struct platform_device_id c_can_id_table[] = {
-        [BOSCH_C_CAN_PLATFORM] = {
-                .name = KBUILD_MODNAME,
-                .driver_data = BOSCH_C_CAN,
-        },
-        [BOSCH_C_CAN] = {
-                .name = "c_can",
-                .driver_data = BOSCH_C_CAN,
-        },
-        [BOSCH_D_CAN] = {
-                .name = "d_can",
-                .driver_data = BOSCH_D_CAN,
-        }, {
-        }
-};
-
 static struct platform_driver c_can_plat_driver = {
         .driver = {
                 .name = KBUILD_MODNAME,
                 .owner = THIS_MODULE,
+                .of_match_table = of_match_ptr(c_can_of_table),
         },
         .probe = c_can_plat_probe,
         .remove = __devexit_p(c_can_plat_remove),