drivers/pwm/pwm-rockchip.c - arm/linux - Git at Google

 /*
  * PWM driver for Rockchip SoCs
  *
  * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
  * Copyright (C) 2014 ROCKCHIP, Inc.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * version 2 as published by the Free Software Foundation.
  */

 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/time.h>

 #define PWM_CTRL_TIMER_EN	(1 << 0)
 #define PWM_CTRL_OUTPUT_EN	(1 << 3)

 #define PWM_ENABLE		(1 << 0)
 #define PWM_CONTINUOUS		(1 << 1)
 #define PWM_DUTY_POSITIVE	(1 << 3)
 #define PWM_DUTY_NEGATIVE	(0 << 3)
 #define PWM_INACTIVE_NEGATIVE	(0 << 4)
 #define PWM_INACTIVE_POSITIVE	(1 << 4)
 #define PWM_OUTPUT_LEFT		(0 << 5)
 #define PWM_LP_DISABLE		(0 << 8)

 struct rockchip_pwm_chip {
 	struct pwm_chip chip;
 	struct clk *clk;
 	const struct rockchip_pwm_data *data;
 	void __iomem *base;
 };

 struct rockchip_pwm_regs {
 	unsigned long duty;
 	unsigned long period;
 	unsigned long cntr;
 	unsigned long ctrl;
 };

 struct rockchip_pwm_data {
 	struct rockchip_pwm_regs regs;
 	unsigned int prescaler;
 	const struct pwm_ops *ops;

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

 static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
 {
 	return container_of(c, struct rockchip_pwm_chip, chip);
 }

 static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
 				       struct pwm_device *pwm, bool enable)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
 	u32 val;

 	val = readl_relaxed(pc->base + pc->data->regs.ctrl);

 	if (enable)
 		val |= enable_conf;
 	else
 		val &= ~enable_conf;

 	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
 }

 static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
 				       struct pwm_device *pwm, bool enable)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
 			  PWM_CONTINUOUS;
 	u32 val;

 	if (pwm_get_polarity(pwm) == PWM_POLARITY_INVERSED)
 		enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
 	else
 		enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;

 	val = readl_relaxed(pc->base + pc->data->regs.ctrl);

 	if (enable)
 		val |= enable_conf;
 	else
 		val &= ~enable_conf;

 	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
 }

 static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			       int duty_ns, int period_ns)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	unsigned long period, duty;
 	u64 clk_rate, div;
 	int ret;

 	clk_rate = clk_get_rate(pc->clk);

 	/*
 	 * Since period and duty cycle registers have a width of 32
 	 * bits, every possible input period can be obtained using the
 	 * default prescaler value for all practical clock rate values.
 	 */
 	div = clk_rate * period_ns;
 	do_div(div, pc->data->prescaler * NSEC_PER_SEC);
 	period = div;

 	div = clk_rate * duty_ns;
 	do_div(div, pc->data->prescaler * NSEC_PER_SEC);
 	duty = div;

 	ret = clk_enable(pc->clk);
 	if (ret)
 		return ret;

 	writel(period, pc->base + pc->data->regs.period);
 	writel(duty, pc->base + pc->data->regs.duty);
 	writel(0, pc->base + pc->data->regs.cntr);

 	clk_disable(pc->clk);

 	return 0;
 }

 static int rockchip_pwm_set_polarity(struct pwm_chip *chip,
 				     struct pwm_device *pwm,
 				     enum pwm_polarity polarity)
 {
 	/*
 	 * No action needed here because pwm->polarity will be set by the core
 	 * and the core will only change polarity when the PWM is not enabled.
 	 * We'll handle things in set_enable().
 	 */

 	return 0;
 }

 static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	int ret;

 	ret = clk_enable(pc->clk);
 	if (ret)
 		return ret;

 	pc->data->set_enable(chip, pwm, true);

 	return 0;
 }

 static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);

 	pc->data->set_enable(chip, pwm, false);

 	clk_disable(pc->clk);
 }

 static const struct pwm_ops rockchip_pwm_ops_v1 = {
 	.config = rockchip_pwm_config,
 	.enable = rockchip_pwm_enable,
 	.disable = rockchip_pwm_disable,
 	.owner = THIS_MODULE,
 };

 static const struct pwm_ops rockchip_pwm_ops_v2 = {
 	.config = rockchip_pwm_config,
 	.set_polarity = rockchip_pwm_set_polarity,
 	.enable = rockchip_pwm_enable,
 	.disable = rockchip_pwm_disable,
 	.owner = THIS_MODULE,
 };

 static const struct rockchip_pwm_data pwm_data_v1 = {
 	.regs = {
 		.duty = 0x04,
 		.period = 0x08,
 		.cntr = 0x00,
 		.ctrl = 0x0c,
 	},
 	.prescaler = 2,
 	.ops = &rockchip_pwm_ops_v1,
 	.set_enable = rockchip_pwm_set_enable_v1,
 };

 static const struct rockchip_pwm_data pwm_data_v2 = {
 	.regs = {
 		.duty = 0x08,
 		.period = 0x04,
 		.cntr = 0x00,
 		.ctrl = 0x0c,
 	},
 	.prescaler = 1,
 	.ops = &rockchip_pwm_ops_v2,
 	.set_enable = rockchip_pwm_set_enable_v2,
 };

 static const struct rockchip_pwm_data pwm_data_vop = {
 	.regs = {
 		.duty = 0x08,
 		.period = 0x04,
 		.cntr = 0x0c,
 		.ctrl = 0x00,
 	},
 	.prescaler = 1,
 	.ops = &rockchip_pwm_ops_v2,
 	.set_enable = rockchip_pwm_set_enable_v2,
 };

 static const struct of_device_id rockchip_pwm_dt_ids[] = {
 	{ .compatible = "rockchip,rk2928-pwm", .data = &pwm_data_v1},
 	{ .compatible = "rockchip,rk3288-pwm", .data = &pwm_data_v2},
 	{ .compatible = "rockchip,vop-pwm", .data = &pwm_data_vop},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, rockchip_pwm_dt_ids);

 static int rockchip_pwm_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *id;
 	struct rockchip_pwm_chip *pc;
 	struct resource *r;
 	int ret;

 	id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev);
 	if (!id)
 		return -EINVAL;

 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
 	if (!pc)
 		return -ENOMEM;

 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pc->base = devm_ioremap_resource(&pdev->dev, r);
 	if (IS_ERR(pc->base))
 		return PTR_ERR(pc->base);

 	pc->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(pc->clk))
 		return PTR_ERR(pc->clk);

 	ret = clk_prepare(pc->clk);
 	if (ret)
 		return ret;

 	platform_set_drvdata(pdev, pc);

 	pc->data = id->data;
 	pc->chip.dev = &pdev->dev;
 	pc->chip.ops = pc->data->ops;
 	pc->chip.base = -1;
 	pc->chip.npwm = 1;

 	if (pc->data->ops->set_polarity) {
 		pc->chip.of_xlate = of_pwm_xlate_with_flags;
 		pc->chip.of_pwm_n_cells = 3;
 	}

 	ret = pwmchip_add(&pc->chip);
 	if (ret < 0) {
 		clk_unprepare(pc->clk);
 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
 	}

 	return ret;
 }

 static int rockchip_pwm_remove(struct platform_device *pdev)
 {
 	struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);

 	clk_unprepare(pc->clk);

 	return pwmchip_remove(&pc->chip);
 }

 static struct platform_driver rockchip_pwm_driver = {
 	.driver = {
 		.name = "rockchip-pwm",
 		.of_match_table = rockchip_pwm_dt_ids,
 	},
 	.probe = rockchip_pwm_probe,
 	.remove = rockchip_pwm_remove,
 };
 module_platform_driver(rockchip_pwm_driver);

 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
 MODULE_DESCRIPTION("Rockchip SoC PWM driver");
 MODULE_LICENSE("GPL v2");
	/*
	* PWM driver for Rockchip SoCs
	*
	* Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
	* Copyright (C) 2014 ROCKCHIP, Inc.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* version 2 as published by the Free Software Foundation.
	*/

	#include <linux/clk.h>
	#include <linux/io.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_device.h>
	#include <linux/platform_device.h>
	#include <linux/pwm.h>
	#include <linux/time.h>

	#define PWM_CTRL_TIMER_EN (1 << 0)
	#define PWM_CTRL_OUTPUT_EN (1 << 3)

	#define PWM_ENABLE (1 << 0)
	#define PWM_CONTINUOUS (1 << 1)
	#define PWM_DUTY_POSITIVE (1 << 3)
	#define PWM_DUTY_NEGATIVE (0 << 3)
	#define PWM_INACTIVE_NEGATIVE (0 << 4)
	#define PWM_INACTIVE_POSITIVE (1 << 4)
	#define PWM_OUTPUT_LEFT (0 << 5)
	#define PWM_LP_DISABLE (0 << 8)

	struct rockchip_pwm_chip {
	struct pwm_chip chip;
	struct clk *clk;
	const struct rockchip_pwm_data *data;
	void __iomem *base;
	};

	struct rockchip_pwm_regs {
	unsigned long duty;
	unsigned long period;
	unsigned long cntr;
	unsigned long ctrl;
	};

	struct rockchip_pwm_data {
	struct rockchip_pwm_regs regs;
	unsigned int prescaler;
	const struct pwm_ops *ops;

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

	static inline struct rockchip_pwm_chip to_rockchip_pwm_chip(struct pwm_chip c)
	{
	return container_of(c, struct rockchip_pwm_chip, chip);
	}

	static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
	struct pwm_device *pwm, bool enable)
	{
	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
	u32 enable_conf = PWM_CTRL_OUTPUT_EN \| PWM_CTRL_TIMER_EN;
	u32 val;

	val = readl_relaxed(pc->base + pc->data->regs.ctrl);

	if (enable)
	val \|= enable_conf;
	else
	val &= ~enable_conf;

	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
	}

	static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
	struct pwm_device *pwm, bool enable)
	{
	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
	u32 enable_conf = PWM_OUTPUT_LEFT \| PWM_LP_DISABLE \| PWM_ENABLE \|
	PWM_CONTINUOUS;
	u32 val;

	if (pwm_get_polarity(pwm) == PWM_POLARITY_INVERSED)
	enable_conf \|= PWM_DUTY_NEGATIVE \| PWM_INACTIVE_POSITIVE;
	else
	enable_conf \|= PWM_DUTY_POSITIVE \| PWM_INACTIVE_NEGATIVE;

	val = readl_relaxed(pc->base + pc->data->regs.ctrl);

	if (enable)
	val \|= enable_conf;
	else
	val &= ~enable_conf;

	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
	}

	static int rockchip_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
	int duty_ns, int period_ns)
	{
	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
	unsigned long period, duty;
	u64 clk_rate, div;
	int ret;

	clk_rate = clk_get_rate(pc->clk);

	/*
	* Since period and duty cycle registers have a width of 32
	* bits, every possible input period can be obtained using the
	* default prescaler value for all practical clock rate values.
	*/
	div = clk_rate * period_ns;
	do_div(div, pc->data->prescaler * NSEC_PER_SEC);
	period = div;

	div = clk_rate * duty_ns;
	do_div(div, pc->data->prescaler * NSEC_PER_SEC);
	duty = div;

	ret = clk_enable(pc->clk);
	if (ret)
	return ret;

	writel(period, pc->base + pc->data->regs.period);
	writel(duty, pc->base + pc->data->regs.duty);
	writel(0, pc->base + pc->data->regs.cntr);

	clk_disable(pc->clk);

	return 0;
	}

	static int rockchip_pwm_set_polarity(struct pwm_chip *chip,
	struct pwm_device *pwm,
	enum pwm_polarity polarity)
	{
	/*
	* No action needed here because pwm->polarity will be set by the core
	* and the core will only change polarity when the PWM is not enabled.
	* We'll handle things in set_enable().
	*/

	return 0;
	}

	static int rockchip_pwm_enable(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
	int ret;

	ret = clk_enable(pc->clk);
	if (ret)
	return ret;

	pc->data->set_enable(chip, pwm, true);

	return 0;
	}

	static void rockchip_pwm_disable(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);

	pc->data->set_enable(chip, pwm, false);

	clk_disable(pc->clk);
	}

	static const struct pwm_ops rockchip_pwm_ops_v1 = {
	.config = rockchip_pwm_config,
	.enable = rockchip_pwm_enable,
	.disable = rockchip_pwm_disable,
	.owner = THIS_MODULE,
	};

	static const struct pwm_ops rockchip_pwm_ops_v2 = {
	.config = rockchip_pwm_config,
	.set_polarity = rockchip_pwm_set_polarity,
	.enable = rockchip_pwm_enable,
	.disable = rockchip_pwm_disable,
	.owner = THIS_MODULE,
	};

	static const struct rockchip_pwm_data pwm_data_v1 = {
	.regs = {
	.duty = 0x04,
	.period = 0x08,
	.cntr = 0x00,
	.ctrl = 0x0c,
	},
	.prescaler = 2,
	.ops = &rockchip_pwm_ops_v1,
	.set_enable = rockchip_pwm_set_enable_v1,
	};

	static const struct rockchip_pwm_data pwm_data_v2 = {
	.regs = {
	.duty = 0x08,
	.period = 0x04,
	.cntr = 0x00,
	.ctrl = 0x0c,
	},
	.prescaler = 1,
	.ops = &rockchip_pwm_ops_v2,
	.set_enable = rockchip_pwm_set_enable_v2,
	};

	static const struct rockchip_pwm_data pwm_data_vop = {
	.regs = {
	.duty = 0x08,
	.period = 0x04,
	.cntr = 0x0c,
	.ctrl = 0x00,
	},
	.prescaler = 1,
	.ops = &rockchip_pwm_ops_v2,
	.set_enable = rockchip_pwm_set_enable_v2,
	};

	static const struct of_device_id rockchip_pwm_dt_ids[] = {
	{ .compatible = "rockchip,rk2928-pwm", .data = &pwm_data_v1},
	{ .compatible = "rockchip,rk3288-pwm", .data = &pwm_data_v2},
	{ .compatible = "rockchip,vop-pwm", .data = &pwm_data_vop},
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, rockchip_pwm_dt_ids);

	static int rockchip_pwm_probe(struct platform_device *pdev)
	{
	const struct of_device_id *id;
	struct rockchip_pwm_chip *pc;
	struct resource *r;
	int ret;

	id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev);
	if (!id)
	return -EINVAL;

	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
	if (!pc)
	return -ENOMEM;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	pc->base = devm_ioremap_resource(&pdev->dev, r);
	if (IS_ERR(pc->base))
	return PTR_ERR(pc->base);

	pc->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(pc->clk))
	return PTR_ERR(pc->clk);

	ret = clk_prepare(pc->clk);
	if (ret)
	return ret;

	platform_set_drvdata(pdev, pc);

	pc->data = id->data;
	pc->chip.dev = &pdev->dev;
	pc->chip.ops = pc->data->ops;
	pc->chip.base = -1;
	pc->chip.npwm = 1;

	if (pc->data->ops->set_polarity) {
	pc->chip.of_xlate = of_pwm_xlate_with_flags;
	pc->chip.of_pwm_n_cells = 3;
	}

	ret = pwmchip_add(&pc->chip);
	if (ret < 0) {
	clk_unprepare(pc->clk);
	dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
	}

	return ret;
	}

	static int rockchip_pwm_remove(struct platform_device *pdev)
	{
	struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);

	clk_unprepare(pc->clk);

	return pwmchip_remove(&pc->chip);
	}

	static struct platform_driver rockchip_pwm_driver = {
	.driver = {
	.name = "rockchip-pwm",
	.of_match_table = rockchip_pwm_dt_ids,
	},
	.probe = rockchip_pwm_probe,
	.remove = rockchip_pwm_remove,
	};
	module_platform_driver(rockchip_pwm_driver);

	MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
	MODULE_DESCRIPTION("Rockchip SoC PWM driver");
	MODULE_LICENSE("GPL v2");