pwm: tegra: Add device tree support

Add auxdata to instantiate the PWFM controller from a device tree,
include the corresponding nodes in the dtsi files for Tegra 20 and
Tegra 30 and add binding documentation.
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>

Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt

+Tegra SoC PWFM controller
+
+Required properties:
+- compatible: should be one of:
+  - "nvidia,tegra20-pwm"
+  - "nvidia,tegra30-pwm"
+- reg: physical base address and length of the controller's registers
+- #pwm-cells: On Tegra the number of cells used to specify a PWM is 2. The
+  first cell specifies the per-chip index of the PWM to use and the second
+  cell is the duty cycle in nanoseconds.
+
+Example:
+
+	pwm: pwm@7000a000 {
+		compatible = "nvidia,tegra20-pwm";
+		reg = <0x7000a000 0x100>;
+		#pwm-cells = <2>;
+	};

arch/arm/boot/dts/tegra20.dtsi

@@ -123,6 +123,12 @@ serial@70006400 {
 		status = "disable";
 	};
 
+	pwm {
+		compatible = "nvidia,tegra20-pwm";
+		reg = <0x7000a000 0x100>;
+		#pwm-cells = <2>;
+	};
+
 	i2c@7000c000 {
 		compatible = "nvidia,tegra20-i2c";
 		reg = <0x7000c000 0x100>;

arch/arm/boot/dts/tegra30.dtsi

@@ -117,6 +117,12 @@ serial@70006400 {
 		status = "disable";
 	};
 
+	pwm {
+		compatible = "nvidia,tegra30-pwm", "nvidia,tegra20-pwm";
+		reg = <0x7000a000 0x100>;
+		#pwm-cells = <2>;
+	};
+
 	i2c@7000c000 {
 		compatible =  "nvidia,tegra30-i2c", "nvidia,tegra20-i2c";
 		reg = <0x7000c000 0x100>;

arch/arm/mach-tegra/board-dt-tegra20.c

@@ -64,6 +64,7 @@ struct of_dev_auxdata tegra20_auxdata_lookup[] __initdata = {
 		       &tegra_ehci2_pdata),
 	OF_DEV_AUXDATA("nvidia,tegra20-ehci", TEGRA_USB3_BASE, "tegra-ehci.2",
 		       &tegra_ehci3_pdata),
+	OF_DEV_AUXDATA("nvidia,tegra20-pwm", TEGRA_PWFM_BASE, "tegra-pwm", NULL),
 	{}
 };
 

arch/arm/mach-tegra/board-dt-tegra30.c

@@ -33,6 +33,8 @@
 #include <asm/mach/arch.h>
 #include <asm/hardware/gic.h>
 
+#include <mach/iomap.h>
+
 #include "board.h"
 #include "clock.h"
 
@@ -52,6 +54,7 @@ struct of_dev_auxdata tegra30_auxdata_lookup[] __initdata = {
 	OF_DEV_AUXDATA("nvidia,tegra20-i2c", 0x7000C700, "tegra-i2c.3", NULL),
 	OF_DEV_AUXDATA("nvidia,tegra20-i2c", 0x7000D000, "tegra-i2c.4", NULL),
 	OF_DEV_AUXDATA("nvidia,tegra30-ahub", 0x70080000, "tegra30-ahub", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra30-pwm", TEGRA_PWFM_BASE, "tegra-pwm", NULL),
 	{}
 };
 

drivers/pwm/pwm-tegra.c

@@ -239,9 +239,20 @@ static int __devexit tegra_pwm_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_OF
+static struct of_device_id tegra_pwm_of_match[] = {
+	{ .compatible = "nvidia,tegra20-pwm" },
+	{ .compatible = "nvidia,tegra30-pwm" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, tegra_pwm_of_match);
+#endif
+
 static struct platform_driver tegra_pwm_driver = {
 	.driver = {
 		.name = "tegra-pwm",
+		.of_match_table = of_match_ptr(tegra_pwm_of_match),
 	},
 	.probe = tegra_pwm_probe,
 	.remove = __devexit_p(tegra_pwm_remove),