pwm: i.MX: add devicetree support

Freescale i.MX PWM controller

Required properties:

- compatible: should be "fsl,<soc>-pwm"

- reg: physical base address and length of the controller's registers

- #pwm-cells: should be 2.  The first cell specifies the per-chip index

  of the PWM to use and the second cell is the duty cycle in nanoseconds.

- interrupts: The interrupt for the pwm controller

Example:

pwm1: pwm@53fb4000 {

	#pwm-cells = <2>;

	compatible = "fsl,imx53-pwm", "fsl,imx27-pwm";

	reg = <0x53fb4000 0x4000>;

	interrupts = <61>;

};

#include <linux/clk.h>

#include <linux/io.h>

#include <linux/pwm.h>

#include <linux/of_device.h>

#include <mach/hardware.h>

/* i.MX1 and i.MX21 share the same PWM function block: */

#define MX1_PWMC    0x00   /* PWM Control Register */

	.owner = THIS_MODULE,

};

struct imx_pwm_data {

	int (*config)(struct pwm_chip *chip,

		struct pwm_device *pwm, int duty_ns, int period_ns);

	void (*set_enable)(struct pwm_chip *chip, bool enable);

};

static struct imx_pwm_data imx_pwm_data_v1 = {

	.config = imx_pwm_config_v1,

	.set_enable = imx_pwm_set_enable_v1,

};

static struct imx_pwm_data imx_pwm_data_v2 = {

	.config = imx_pwm_config_v2,

	.set_enable = imx_pwm_set_enable_v2,

};

static const struct of_device_id imx_pwm_dt_ids[] = {

	{ .compatible = "fsl,imx1-pwm", .data = &imx_pwm_data_v1, },

	{ .compatible = "fsl,imx27-pwm", .data = &imx_pwm_data_v2, },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, imx_pwm_dt_ids);

static int __devinit imx_pwm_probe(struct platform_device *pdev)

{

	const struct of_device_id *of_id =

			of_match_device(imx_pwm_dt_ids, &pdev->dev);

	struct imx_pwm_data *data;

	struct imx_chip *imx;

	struct resource *r;

	int ret = 0;

	if (!of_id)

		return -ENODEV;

	imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL);

	if (imx == NULL) {

		dev_err(&pdev->dev, "failed to allocate memory\n");

	if (imx->mmio_base == NULL)

		return -EADDRNOTAVAIL;

	if (cpu_is_mx1() || cpu_is_mx21()) {

		imx->config = imx_pwm_config_v1;

		imx->set_enable = imx_pwm_set_enable_v1;

	} else {

		imx->config = imx_pwm_config_v2;

		imx->set_enable = imx_pwm_set_enable_v2;

	}

	data = of_id->data;

	imx->config = data->config;

	imx->set_enable = data->set_enable;

	ret = pwmchip_add(&imx->chip);

	if (ret < 0)

static struct platform_driver imx_pwm_driver = {

	.driver		= {

		.name	= "mxc_pwm",

		.name	= "imx-pwm",

		.of_match_table = of_match_ptr(imx_pwm_dt_ids),

	},

	.probe		= imx_pwm_probe,

	.remove		= __devexit_p(imx_pwm_remove),