drivers/pwm/pwm-atmel-hlcdc.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2014 Free Electrons
  * Copyright (C) 2014 Atmel
  *
  * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
  */

 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/mfd/atmel-hlcdc.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/regmap.h>

 #define ATMEL_HLCDC_PWMCVAL_MASK	GENMASK(15, 8)
 #define ATMEL_HLCDC_PWMCVAL(x)		(((x) << 8) & ATMEL_HLCDC_PWMCVAL_MASK)
 #define ATMEL_HLCDC_PWMPOL		BIT(4)
 #define ATMEL_HLCDC_PWMPS_MASK		GENMASK(2, 0)
 #define ATMEL_HLCDC_PWMPS_MAX		0x6
 #define ATMEL_HLCDC_PWMPS(x)		((x) & ATMEL_HLCDC_PWMPS_MASK)

 struct atmel_hlcdc_pwm_errata {
 	bool slow_clk_erratum;
 	bool div1_clk_erratum;
 };

 struct atmel_hlcdc_pwm {
 	struct atmel_hlcdc *hlcdc;
 	struct clk *cur_clk;
 	const struct atmel_hlcdc_pwm_errata *errata;
 };

 static inline struct atmel_hlcdc_pwm *to_atmel_hlcdc_pwm(struct pwm_chip *chip)
 {
 	return pwmchip_get_drvdata(chip);
 }

 static int atmel_hlcdc_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 				 const struct pwm_state *state)
 {
 	struct atmel_hlcdc_pwm *atmel = to_atmel_hlcdc_pwm(chip);
 	struct atmel_hlcdc *hlcdc = atmel->hlcdc;
 	unsigned int status;
 	int ret;

 	if (state->enabled) {
 		struct clk *new_clk = hlcdc->slow_clk;
 		u64 pwmcval = state->duty_cycle * 256;
 		unsigned long clk_freq;
 		u64 clk_period_ns;
 		u32 pwmcfg;
 		int pres;

 		if (!atmel->errata || !atmel->errata->slow_clk_erratum) {
 			clk_freq = clk_get_rate(new_clk);
 			if (!clk_freq)
 				return -EINVAL;

 			clk_period_ns = (u64)NSEC_PER_SEC * 256;
 			do_div(clk_period_ns, clk_freq);
 		}

 		/* Errata: cannot use slow clk on some IP revisions */
 		if ((atmel->errata && atmel->errata->slow_clk_erratum) ||
 		    clk_period_ns > state->period) {
 			new_clk = hlcdc->sys_clk;
 			clk_freq = clk_get_rate(new_clk);
 			if (!clk_freq)
 				return -EINVAL;

 			clk_period_ns = (u64)NSEC_PER_SEC * 256;
 			do_div(clk_period_ns, clk_freq);
 		}

 		for (pres = 0; pres <= ATMEL_HLCDC_PWMPS_MAX; pres++) {
 		/* Errata: cannot divide by 1 on some IP revisions */
 			if (!pres && atmel->errata &&
 			    atmel->errata->div1_clk_erratum)
 				continue;

 			if ((clk_period_ns << pres) >= state->period)
 				break;
 		}

 		if (pres > ATMEL_HLCDC_PWMPS_MAX)
 			return -EINVAL;

 		pwmcfg = ATMEL_HLCDC_PWMPS(pres);

 		if (new_clk != atmel->cur_clk) {
 			u32 gencfg = 0;
 			int ret;

 			ret = clk_prepare_enable(new_clk);
 			if (ret)
 				return ret;

 			clk_disable_unprepare(atmel->cur_clk);
 			atmel->cur_clk = new_clk;

 			if (new_clk == hlcdc->sys_clk)
 				gencfg = ATMEL_HLCDC_CLKPWMSEL;

 			ret = regmap_update_bits(hlcdc->regmap,
 						 ATMEL_HLCDC_CFG(0),
 						 ATMEL_HLCDC_CLKPWMSEL,
 						 gencfg);
 			if (ret)
 				return ret;
 		}

 		do_div(pwmcval, state->period);

 		/*
 		 * The PWM duty cycle is configurable from 0/256 to 255/256 of
 		 * the period cycle. Hence we can't set a duty cycle occupying
 		 * the whole period cycle if we're asked to.
 		 * Set it to 255 if pwmcval is greater than 256.
 		 */
 		if (pwmcval > 255)
 			pwmcval = 255;

 		pwmcfg |= ATMEL_HLCDC_PWMCVAL(pwmcval);

 		if (state->polarity == PWM_POLARITY_NORMAL)
 			pwmcfg |= ATMEL_HLCDC_PWMPOL;

 		ret = regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
 					 ATMEL_HLCDC_PWMCVAL_MASK |
 					 ATMEL_HLCDC_PWMPS_MASK |
 					 ATMEL_HLCDC_PWMPOL,
 					 pwmcfg);
 		if (ret)
 			return ret;

 		ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_EN,
 				   ATMEL_HLCDC_PWM);
 		if (ret)
 			return ret;

 		ret = regmap_read_poll_timeout(hlcdc->regmap, ATMEL_HLCDC_SR,
 					       status,
 					       status & ATMEL_HLCDC_PWM,
 					       10, 0);
 		if (ret)
 			return ret;
 	} else {
 		ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_DIS,
 				   ATMEL_HLCDC_PWM);
 		if (ret)
 			return ret;

 		ret = regmap_read_poll_timeout(hlcdc->regmap, ATMEL_HLCDC_SR,
 					       status,
 					       !(status & ATMEL_HLCDC_PWM),
 					       10, 0);
 		if (ret)
 			return ret;

 		clk_disable_unprepare(atmel->cur_clk);
 		atmel->cur_clk = NULL;
 	}

 	return 0;
 }

 static const struct pwm_ops atmel_hlcdc_pwm_ops = {
 	.apply = atmel_hlcdc_pwm_apply,
 };

 static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_at91sam9x5_errata = {
 	.slow_clk_erratum = true,
 };

 static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_sama5d3_errata = {
 	.div1_clk_erratum = true,
 };

 static int atmel_hlcdc_pwm_suspend(struct device *dev)
 {
 	struct pwm_chip *chip = dev_get_drvdata(dev);
 	struct atmel_hlcdc_pwm *atmel = to_atmel_hlcdc_pwm(chip);
 	struct pwm_device *pwm = &chip->pwms[0];

 	/* Keep the periph clock enabled if the PWM is still running. */
 	if (!pwm->state.enabled)
 		clk_disable_unprepare(atmel->hlcdc->periph_clk);

 	return 0;
 }

 static int atmel_hlcdc_pwm_resume(struct device *dev)
 {
 	struct pwm_chip *chip = dev_get_drvdata(dev);
 	struct atmel_hlcdc_pwm *atmel = to_atmel_hlcdc_pwm(chip);
 	struct pwm_device *pwm = &chip->pwms[0];
 	int ret;

 	/* Re-enable the periph clock it was stopped during suspend. */
 	if (!pwm->state.enabled) {
 		ret = clk_prepare_enable(atmel->hlcdc->periph_clk);
 		if (ret)
 			return ret;
 	}

 	return atmel_hlcdc_pwm_apply(chip, pwm, &pwm->state);
 }

 static DEFINE_SIMPLE_DEV_PM_OPS(atmel_hlcdc_pwm_pm_ops,
 				atmel_hlcdc_pwm_suspend, atmel_hlcdc_pwm_resume);

 static const struct of_device_id atmel_hlcdc_dt_ids[] = {
 	{
 		.compatible = "atmel,at91sam9n12-hlcdc",
 		/* 9n12 has same errata as 9x5 HLCDC PWM */
 		.data = &atmel_hlcdc_pwm_at91sam9x5_errata,
 	},
 	{
 		.compatible = "atmel,at91sam9x5-hlcdc",
 		.data = &atmel_hlcdc_pwm_at91sam9x5_errata,
 	},
 	{
 		.compatible = "atmel,sama5d2-hlcdc",
 	},
 	{
 		.compatible = "atmel,sama5d3-hlcdc",
 		.data = &atmel_hlcdc_pwm_sama5d3_errata,
 	},
 	{
 		.compatible = "atmel,sama5d4-hlcdc",
 		.data = &atmel_hlcdc_pwm_sama5d3_errata,
 	},
 	{	.compatible = "microchip,sam9x60-hlcdc", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, atmel_hlcdc_dt_ids);

 static int atmel_hlcdc_pwm_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *match;
 	struct device *dev = &pdev->dev;
 	struct pwm_chip *chip;
 	struct atmel_hlcdc_pwm *atmel;
 	struct atmel_hlcdc *hlcdc;
 	int ret;

 	hlcdc = dev_get_drvdata(dev->parent);

 	chip = devm_pwmchip_alloc(dev, 1, sizeof(*atmel));
 	if (IS_ERR(chip))
 		return PTR_ERR(chip);
 	atmel = to_atmel_hlcdc_pwm(chip);

 	ret = clk_prepare_enable(hlcdc->periph_clk);
 	if (ret)
 		return ret;

 	match = of_match_node(atmel_hlcdc_dt_ids, dev->parent->of_node);
 	if (match)
 		atmel->errata = match->data;

 	atmel->hlcdc = hlcdc;
 	chip->ops = &atmel_hlcdc_pwm_ops;

 	ret = pwmchip_add(chip);
 	if (ret) {
 		clk_disable_unprepare(hlcdc->periph_clk);
 		return ret;
 	}

 	platform_set_drvdata(pdev, chip);

 	return 0;
 }

 static void atmel_hlcdc_pwm_remove(struct platform_device *pdev)
 {
 	struct pwm_chip *chip = platform_get_drvdata(pdev);
 	struct atmel_hlcdc_pwm *atmel = to_atmel_hlcdc_pwm(chip);

 	pwmchip_remove(chip);

 	clk_disable_unprepare(atmel->hlcdc->periph_clk);
 }

 static const struct of_device_id atmel_hlcdc_pwm_dt_ids[] = {
 	{ .compatible = "atmel,hlcdc-pwm" },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, atmel_hlcdc_pwm_dt_ids);

 static struct platform_driver atmel_hlcdc_pwm_driver = {
 	.driver = {
 		.name = "atmel-hlcdc-pwm",
 		.of_match_table = atmel_hlcdc_pwm_dt_ids,
 		.pm = pm_ptr(&atmel_hlcdc_pwm_pm_ops),
 	},
 	.probe = atmel_hlcdc_pwm_probe,
 	.remove = atmel_hlcdc_pwm_remove,
 };
 module_platform_driver(atmel_hlcdc_pwm_driver);

 MODULE_ALIAS("platform:atmel-hlcdc-pwm");
 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
 MODULE_DESCRIPTION("Atmel HLCDC PWM driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2014 Free Electrons
	* Copyright (C) 2014 Atmel
	*
	* Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
	*/

	#include <linux/clk.h>
	#include <linux/delay.h>
	#include <linux/mfd/atmel-hlcdc.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/pwm.h>
	#include <linux/regmap.h>

	#define ATMEL_HLCDC_PWMCVAL_MASK GENMASK(15, 8)
	#define ATMEL_HLCDC_PWMCVAL(x) (((x) << 8) & ATMEL_HLCDC_PWMCVAL_MASK)
	#define ATMEL_HLCDC_PWMPOL BIT(4)
	#define ATMEL_HLCDC_PWMPS_MASK GENMASK(2, 0)
	#define ATMEL_HLCDC_PWMPS_MAX 0x6
	#define ATMEL_HLCDC_PWMPS(x) ((x) & ATMEL_HLCDC_PWMPS_MASK)

	struct atmel_hlcdc_pwm_errata {
	bool slow_clk_erratum;
	bool div1_clk_erratum;
	};

	struct atmel_hlcdc_pwm {
	struct atmel_hlcdc *hlcdc;
	struct clk *cur_clk;
	const struct atmel_hlcdc_pwm_errata *errata;
	};

	static inline struct atmel_hlcdc_pwm to_atmel_hlcdc_pwm(struct pwm_chip chip)
	{
	return pwmchip_get_drvdata(chip);
	}

	static int atmel_hlcdc_pwm_apply(struct pwm_chip chip, struct pwm_device pwm,
	const struct pwm_state *state)
	{
	struct atmel_hlcdc_pwm *atmel = to_atmel_hlcdc_pwm(chip);
	struct atmel_hlcdc *hlcdc = atmel->hlcdc;
	unsigned int status;
	int ret;

	if (state->enabled) {
	struct clk *new_clk = hlcdc->slow_clk;
	u64 pwmcval = state->duty_cycle * 256;
	unsigned long clk_freq;
	u64 clk_period_ns;
	u32 pwmcfg;
	int pres;

	if (!atmel->errata \|\| !atmel->errata->slow_clk_erratum) {
	clk_freq = clk_get_rate(new_clk);
	if (!clk_freq)
	return -EINVAL;

	clk_period_ns = (u64)NSEC_PER_SEC * 256;
	do_div(clk_period_ns, clk_freq);
	}

	/* Errata: cannot use slow clk on some IP revisions */
	if ((atmel->errata && atmel->errata->slow_clk_erratum) \|\|
	clk_period_ns > state->period) {
	new_clk = hlcdc->sys_clk;
	clk_freq = clk_get_rate(new_clk);
	if (!clk_freq)
	return -EINVAL;

	clk_period_ns = (u64)NSEC_PER_SEC * 256;
	do_div(clk_period_ns, clk_freq);
	}

	for (pres = 0; pres <= ATMEL_HLCDC_PWMPS_MAX; pres++) {
	/* Errata: cannot divide by 1 on some IP revisions */
	if (!pres && atmel->errata &&
	atmel->errata->div1_clk_erratum)
	continue;

	if ((clk_period_ns << pres) >= state->period)
	break;
	}

	if (pres > ATMEL_HLCDC_PWMPS_MAX)
	return -EINVAL;

	pwmcfg = ATMEL_HLCDC_PWMPS(pres);

	if (new_clk != atmel->cur_clk) {
	u32 gencfg = 0;
	int ret;

	ret = clk_prepare_enable(new_clk);
	if (ret)
	return ret;

	clk_disable_unprepare(atmel->cur_clk);
	atmel->cur_clk = new_clk;

	if (new_clk == hlcdc->sys_clk)
	gencfg = ATMEL_HLCDC_CLKPWMSEL;

	ret = regmap_update_bits(hlcdc->regmap,
	ATMEL_HLCDC_CFG(0),
	ATMEL_HLCDC_CLKPWMSEL,
	gencfg);
	if (ret)
	return ret;
	}

	do_div(pwmcval, state->period);

	/*
	* The PWM duty cycle is configurable from 0/256 to 255/256 of
	* the period cycle. Hence we can't set a duty cycle occupying
	* the whole period cycle if we're asked to.
	* Set it to 255 if pwmcval is greater than 256.
	*/
	if (pwmcval > 255)
	pwmcval = 255;

	pwmcfg \|= ATMEL_HLCDC_PWMCVAL(pwmcval);

	if (state->polarity == PWM_POLARITY_NORMAL)
	pwmcfg \|= ATMEL_HLCDC_PWMPOL;

	ret = regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
	ATMEL_HLCDC_PWMCVAL_MASK \|
	ATMEL_HLCDC_PWMPS_MASK \|
	ATMEL_HLCDC_PWMPOL,
	pwmcfg);
	if (ret)
	return ret;

	ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_EN,
	ATMEL_HLCDC_PWM);
	if (ret)
	return ret;

	ret = regmap_read_poll_timeout(hlcdc->regmap, ATMEL_HLCDC_SR,
	status,
	status & ATMEL_HLCDC_PWM,
	10, 0);
	if (ret)
	return ret;
	} else {
	ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_DIS,
	ATMEL_HLCDC_PWM);
	if (ret)
	return ret;

	ret = regmap_read_poll_timeout(hlcdc->regmap, ATMEL_HLCDC_SR,
	status,
	!(status & ATMEL_HLCDC_PWM),
	10, 0);
	if (ret)
	return ret;

	clk_disable_unprepare(atmel->cur_clk);
	atmel->cur_clk = NULL;
	}

	return 0;
	}

	static const struct pwm_ops atmel_hlcdc_pwm_ops = {
	.apply = atmel_hlcdc_pwm_apply,
	};

	static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_at91sam9x5_errata = {
	.slow_clk_erratum = true,
	};

	static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_sama5d3_errata = {
	.div1_clk_erratum = true,
	};

	static int atmel_hlcdc_pwm_suspend(struct device *dev)
	{
	struct pwm_chip *chip = dev_get_drvdata(dev);
	struct atmel_hlcdc_pwm *atmel = to_atmel_hlcdc_pwm(chip);
	struct pwm_device *pwm = &chip->pwms[0];

	/* Keep the periph clock enabled if the PWM is still running. */
	if (!pwm->state.enabled)
	clk_disable_unprepare(atmel->hlcdc->periph_clk);

	return 0;
	}

	static int atmel_hlcdc_pwm_resume(struct device *dev)
	{
	struct pwm_chip *chip = dev_get_drvdata(dev);
	struct atmel_hlcdc_pwm *atmel = to_atmel_hlcdc_pwm(chip);
	struct pwm_device *pwm = &chip->pwms[0];
	int ret;

	/* Re-enable the periph clock it was stopped during suspend. */
	if (!pwm->state.enabled) {
	ret = clk_prepare_enable(atmel->hlcdc->periph_clk);
	if (ret)
	return ret;
	}

	return atmel_hlcdc_pwm_apply(chip, pwm, &pwm->state);
	}

	static DEFINE_SIMPLE_DEV_PM_OPS(atmel_hlcdc_pwm_pm_ops,
	atmel_hlcdc_pwm_suspend, atmel_hlcdc_pwm_resume);

	static const struct of_device_id atmel_hlcdc_dt_ids[] = {
	{
	.compatible = "atmel,at91sam9n12-hlcdc",
	/* 9n12 has same errata as 9x5 HLCDC PWM */
	.data = &atmel_hlcdc_pwm_at91sam9x5_errata,
	},
	{
	.compatible = "atmel,at91sam9x5-hlcdc",
	.data = &atmel_hlcdc_pwm_at91sam9x5_errata,
	},
	{
	.compatible = "atmel,sama5d2-hlcdc",
	},
	{
	.compatible = "atmel,sama5d3-hlcdc",
	.data = &atmel_hlcdc_pwm_sama5d3_errata,
	},
	{
	.compatible = "atmel,sama5d4-hlcdc",
	.data = &atmel_hlcdc_pwm_sama5d3_errata,
	},
	{ .compatible = "microchip,sam9x60-hlcdc", },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, atmel_hlcdc_dt_ids);

	static int atmel_hlcdc_pwm_probe(struct platform_device *pdev)
	{
	const struct of_device_id *match;
	struct device *dev = &pdev->dev;
	struct pwm_chip *chip;
	struct atmel_hlcdc_pwm *atmel;
	struct atmel_hlcdc *hlcdc;
	int ret;

	hlcdc = dev_get_drvdata(dev->parent);

	chip = devm_pwmchip_alloc(dev, 1, sizeof(*atmel));
	if (IS_ERR(chip))
	return PTR_ERR(chip);
	atmel = to_atmel_hlcdc_pwm(chip);

	ret = clk_prepare_enable(hlcdc->periph_clk);
	if (ret)
	return ret;

	match = of_match_node(atmel_hlcdc_dt_ids, dev->parent->of_node);
	if (match)
	atmel->errata = match->data;

	atmel->hlcdc = hlcdc;
	chip->ops = &atmel_hlcdc_pwm_ops;

	ret = pwmchip_add(chip);
	if (ret) {
	clk_disable_unprepare(hlcdc->periph_clk);
	return ret;
	}

	platform_set_drvdata(pdev, chip);

	return 0;
	}

	static void atmel_hlcdc_pwm_remove(struct platform_device *pdev)
	{
	struct pwm_chip *chip = platform_get_drvdata(pdev);
	struct atmel_hlcdc_pwm *atmel = to_atmel_hlcdc_pwm(chip);

	pwmchip_remove(chip);

	clk_disable_unprepare(atmel->hlcdc->periph_clk);
	}

	static const struct of_device_id atmel_hlcdc_pwm_dt_ids[] = {
	{ .compatible = "atmel,hlcdc-pwm" },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, atmel_hlcdc_pwm_dt_ids);

	static struct platform_driver atmel_hlcdc_pwm_driver = {
	.driver = {
	.name = "atmel-hlcdc-pwm",
	.of_match_table = atmel_hlcdc_pwm_dt_ids,
	.pm = pm_ptr(&atmel_hlcdc_pwm_pm_ops),
	},
	.probe = atmel_hlcdc_pwm_probe,
	.remove = atmel_hlcdc_pwm_remove,
	};
	module_platform_driver(atmel_hlcdc_pwm_driver);

	MODULE_ALIAS("platform:atmel-hlcdc-pwm");
	MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
	MODULE_DESCRIPTION("Atmel HLCDC PWM driver");
	MODULE_LICENSE("GPL v2");