drivers/pwm/pwm-lp3943.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * TI/National Semiconductor LP3943 PWM driver
  *
  * Copyright 2013 Texas Instruments
  *
  * Author: Milo Kim <milo.kim@ti.com>
  */

 #include <linux/err.h>
 #include <linux/mfd/lp3943.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>

 #define LP3943_MAX_DUTY			255
 #define LP3943_MIN_PERIOD		6250
 #define LP3943_MAX_PERIOD		1600000

 struct lp3943_pwm {
 	struct lp3943 *lp3943;
 	struct lp3943_platform_data *pdata;
 	struct lp3943_pwm_map pwm_map[LP3943_NUM_PWMS];
 };

 static inline struct lp3943_pwm *to_lp3943_pwm(struct pwm_chip *chip)
 {
 	return pwmchip_get_drvdata(chip);
 }

 static struct lp3943_pwm_map *
 lp3943_pwm_request_map(struct lp3943_pwm *lp3943_pwm, int hwpwm)
 {
 	struct lp3943_platform_data *pdata = lp3943_pwm->pdata;
 	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
 	struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[hwpwm];
 	int i, offset;

 	pwm_map->output = pdata->pwms[hwpwm]->output;
 	pwm_map->num_outputs = pdata->pwms[hwpwm]->num_outputs;

 	for (i = 0; i < pwm_map->num_outputs; i++) {
 		offset = pwm_map->output[i];

 		/* Return an error if the pin is already assigned */
 		if (test_and_set_bit(offset, &lp3943->pin_used))
 			return ERR_PTR(-EBUSY);
 	}

 	return pwm_map;
 }

 static int lp3943_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
 	struct lp3943_pwm_map *pwm_map;

 	pwm_map = lp3943_pwm_request_map(lp3943_pwm, pwm->hwpwm);
 	if (IS_ERR(pwm_map))
 		return PTR_ERR(pwm_map);

 	return 0;
 }

 static void lp3943_pwm_free_map(struct lp3943_pwm *lp3943_pwm,
 				struct lp3943_pwm_map *pwm_map)
 {
 	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
 	int i, offset;

 	for (i = 0; i < pwm_map->num_outputs; i++) {
 		offset = pwm_map->output[i];
 		clear_bit(offset, &lp3943->pin_used);
 	}
 }

 static void lp3943_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
 	struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[pwm->hwpwm];

 	lp3943_pwm_free_map(lp3943_pwm, pwm_map);
 }

 static int lp3943_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			     u64 duty_ns, u64 period_ns)
 {
 	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
 	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
 	u8 val, reg_duty, reg_prescale;
 	int err;

 	/*
 	 * How to configure the LP3943 PWMs
 	 *
 	 * 1) Period = 6250 ~ 1600000
 	 * 2) Prescale = period / 6250 -1
 	 * 3) Duty = input duty
 	 *
 	 * Prescale and duty are register values
 	 */

 	if (pwm->hwpwm == 0) {
 		reg_prescale = LP3943_REG_PRESCALE0;
 		reg_duty     = LP3943_REG_PWM0;
 	} else {
 		reg_prescale = LP3943_REG_PRESCALE1;
 		reg_duty     = LP3943_REG_PWM1;
 	}

 	/*
 	 * Note that after this clamping, period_ns fits into an int. This is
 	 * helpful because we can resort to integer division below instead of
 	 * the (more expensive) 64 bit division.
 	 */
 	period_ns = clamp(period_ns, (u64)LP3943_MIN_PERIOD, (u64)LP3943_MAX_PERIOD);
 	val       = (u8)((int)period_ns / LP3943_MIN_PERIOD - 1);

 	err = lp3943_write_byte(lp3943, reg_prescale, val);
 	if (err)
 		return err;

 	duty_ns = min(duty_ns, period_ns);
 	val = (u8)((int)duty_ns * LP3943_MAX_DUTY / (int)period_ns);

 	return lp3943_write_byte(lp3943, reg_duty, val);
 }

 static int lp3943_pwm_set_mode(struct lp3943_pwm *lp3943_pwm,
 			       struct lp3943_pwm_map *pwm_map,
 			       u8 val)
 {
 	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
 	const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
 	int i, index, err;

 	for (i = 0; i < pwm_map->num_outputs; i++) {
 		index = pwm_map->output[i];
 		err = lp3943_update_bits(lp3943, mux[index].reg,
 					 mux[index].mask,
 					 val << mux[index].shift);
 		if (err)
 			return err;
 	}

 	return 0;
 }

 static int lp3943_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
 	struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[pwm->hwpwm];
 	u8 val;

 	if (pwm->hwpwm == 0)
 		val = LP3943_DIM_PWM0;
 	else
 		val = LP3943_DIM_PWM1;

 	/*
 	 * Each PWM generator is set to control any of outputs of LP3943.
 	 * To enable/disable the PWM, these output pins should be configured.
 	 */

 	return lp3943_pwm_set_mode(lp3943_pwm, pwm_map, val);
 }

 static void lp3943_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
 	struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[pwm->hwpwm];

 	/*
 	 * LP3943 outputs are open-drain, so the pin should be configured
 	 * when the PWM is disabled.
 	 */

 	lp3943_pwm_set_mode(lp3943_pwm, pwm_map, LP3943_GPIO_OUT_HIGH);
 }

 static int lp3943_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			    const struct pwm_state *state)
 {
 	int err;

 	if (state->polarity != PWM_POLARITY_NORMAL)
 		return -EINVAL;

 	if (!state->enabled) {
 		if (pwm->state.enabled)
 			lp3943_pwm_disable(chip, pwm);
 		return 0;
 	}

 	err = lp3943_pwm_config(chip, pwm, state->duty_cycle, state->period);
 	if (err)
 		return err;

 	if (!pwm->state.enabled)
 		err = lp3943_pwm_enable(chip, pwm);

 	return err;
 }

 static const struct pwm_ops lp3943_pwm_ops = {
 	.request	= lp3943_pwm_request,
 	.free		= lp3943_pwm_free,
 	.apply		= lp3943_pwm_apply,
 };

 static int lp3943_pwm_parse_dt(struct device *dev,
 			       struct lp3943_pwm *lp3943_pwm)
 {
 	static const char * const name[] = { "ti,pwm0", "ti,pwm1", };
 	struct device_node *node = dev->of_node;
 	struct lp3943_platform_data *pdata;
 	struct lp3943_pwm_map *pwm_map;
 	enum lp3943_pwm_output *output;
 	int i, err, num_outputs, count = 0;

 	if (!node)
 		return -EINVAL;

 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;

 	/*
 	 * Read the output map configuration from the device tree.
 	 * Each of the two PWM generators can drive zero or more outputs.
 	 */

 	for (i = 0; i < LP3943_NUM_PWMS; i++) {
 		num_outputs = of_property_count_u32_elems(node, name[i]);
 		if (num_outputs <= 0)
 			continue;

 		output = devm_kcalloc(dev, num_outputs, sizeof(*output),
 				      GFP_KERNEL);
 		if (!output)
 			return -ENOMEM;

 		err = of_property_read_u32_array(node, name[i], output,
 						 num_outputs);
 		if (err)
 			return err;

 		pwm_map = devm_kzalloc(dev, sizeof(*pwm_map), GFP_KERNEL);
 		if (!pwm_map)
 			return -ENOMEM;

 		pwm_map->output = output;
 		pwm_map->num_outputs = num_outputs;
 		pdata->pwms[i] = pwm_map;

 		count++;
 	}

 	if (count == 0)
 		return -ENODATA;

 	lp3943_pwm->pdata = pdata;
 	return 0;
 }

 static int lp3943_pwm_probe(struct platform_device *pdev)
 {
 	struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
 	struct pwm_chip *chip;
 	struct lp3943_pwm *lp3943_pwm;
 	int ret;

 	chip = devm_pwmchip_alloc(&pdev->dev, LP3943_NUM_PWMS, sizeof(*lp3943_pwm));
 	if (IS_ERR(chip))
 		return PTR_ERR(chip);
 	lp3943_pwm = to_lp3943_pwm(chip);

 	lp3943_pwm->pdata = lp3943->pdata;
 	if (!lp3943_pwm->pdata) {
 		if (IS_ENABLED(CONFIG_OF))
 			ret = lp3943_pwm_parse_dt(&pdev->dev, lp3943_pwm);
 		else
 			ret = -ENODEV;

 		if (ret)
 			return ret;
 	}

 	lp3943_pwm->lp3943 = lp3943;
 	chip->ops = &lp3943_pwm_ops;

 	return devm_pwmchip_add(&pdev->dev, chip);
 }

 #ifdef CONFIG_OF
 static const struct of_device_id lp3943_pwm_of_match[] = {
 	{ .compatible = "ti,lp3943-pwm", },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, lp3943_pwm_of_match);
 #endif

 static struct platform_driver lp3943_pwm_driver = {
 	.probe = lp3943_pwm_probe,
 	.driver = {
 		.name = "lp3943-pwm",
 		.of_match_table = of_match_ptr(lp3943_pwm_of_match),
 	},
 };
 module_platform_driver(lp3943_pwm_driver);

 MODULE_DESCRIPTION("LP3943 PWM driver");
 MODULE_ALIAS("platform:lp3943-pwm");
 MODULE_AUTHOR("Milo Kim");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* TI/National Semiconductor LP3943 PWM driver
	*
	* Copyright 2013 Texas Instruments
	*
	* Author: Milo Kim <milo.kim@ti.com>
	*/

	#include <linux/err.h>
	#include <linux/mfd/lp3943.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/pwm.h>
	#include <linux/slab.h>

	#define LP3943_MAX_DUTY 255
	#define LP3943_MIN_PERIOD 6250
	#define LP3943_MAX_PERIOD 1600000

	struct lp3943_pwm {
	struct lp3943 *lp3943;
	struct lp3943_platform_data *pdata;
	struct lp3943_pwm_map pwm_map[LP3943_NUM_PWMS];
	};

	static inline struct lp3943_pwm to_lp3943_pwm(struct pwm_chip chip)
	{
	return pwmchip_get_drvdata(chip);
	}

	static struct lp3943_pwm_map *
	lp3943_pwm_request_map(struct lp3943_pwm *lp3943_pwm, int hwpwm)
	{
	struct lp3943_platform_data *pdata = lp3943_pwm->pdata;
	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
	struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[hwpwm];
	int i, offset;

	pwm_map->output = pdata->pwms[hwpwm]->output;
	pwm_map->num_outputs = pdata->pwms[hwpwm]->num_outputs;

	for (i = 0; i < pwm_map->num_outputs; i++) {
	offset = pwm_map->output[i];

	/* Return an error if the pin is already assigned */
	if (test_and_set_bit(offset, &lp3943->pin_used))
	return ERR_PTR(-EBUSY);
	}

	return pwm_map;
	}

	static int lp3943_pwm_request(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
	struct lp3943_pwm_map *pwm_map;

	pwm_map = lp3943_pwm_request_map(lp3943_pwm, pwm->hwpwm);
	if (IS_ERR(pwm_map))
	return PTR_ERR(pwm_map);

	return 0;
	}

	static void lp3943_pwm_free_map(struct lp3943_pwm *lp3943_pwm,
	struct lp3943_pwm_map *pwm_map)
	{
	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
	int i, offset;

	for (i = 0; i < pwm_map->num_outputs; i++) {
	offset = pwm_map->output[i];
	clear_bit(offset, &lp3943->pin_used);
	}
	}

	static void lp3943_pwm_free(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
	struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[pwm->hwpwm];

	lp3943_pwm_free_map(lp3943_pwm, pwm_map);
	}

	static int lp3943_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
	u64 duty_ns, u64 period_ns)
	{
	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
	u8 val, reg_duty, reg_prescale;
	int err;

	/*
	* How to configure the LP3943 PWMs
	*
	* 1) Period = 6250 ~ 1600000
	* 2) Prescale = period / 6250 -1
	* 3) Duty = input duty
	*
	* Prescale and duty are register values
	*/

	if (pwm->hwpwm == 0) {
	reg_prescale = LP3943_REG_PRESCALE0;
	reg_duty = LP3943_REG_PWM0;
	} else {
	reg_prescale = LP3943_REG_PRESCALE1;
	reg_duty = LP3943_REG_PWM1;
	}

	/*
	* Note that after this clamping, period_ns fits into an int. This is
	* helpful because we can resort to integer division below instead of
	* the (more expensive) 64 bit division.
	*/
	period_ns = clamp(period_ns, (u64)LP3943_MIN_PERIOD, (u64)LP3943_MAX_PERIOD);
	val = (u8)((int)period_ns / LP3943_MIN_PERIOD - 1);

	err = lp3943_write_byte(lp3943, reg_prescale, val);
	if (err)
	return err;

	duty_ns = min(duty_ns, period_ns);
	val = (u8)((int)duty_ns * LP3943_MAX_DUTY / (int)period_ns);

	return lp3943_write_byte(lp3943, reg_duty, val);
	}

	static int lp3943_pwm_set_mode(struct lp3943_pwm *lp3943_pwm,
	struct lp3943_pwm_map *pwm_map,
	u8 val)
	{
	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
	const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
	int i, index, err;

	for (i = 0; i < pwm_map->num_outputs; i++) {
	index = pwm_map->output[i];
	err = lp3943_update_bits(lp3943, mux[index].reg,
	mux[index].mask,
	val << mux[index].shift);
	if (err)
	return err;
	}

	return 0;
	}

	static int lp3943_pwm_enable(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
	struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[pwm->hwpwm];
	u8 val;

	if (pwm->hwpwm == 0)
	val = LP3943_DIM_PWM0;
	else
	val = LP3943_DIM_PWM1;

	/*
	* Each PWM generator is set to control any of outputs of LP3943.
	* To enable/disable the PWM, these output pins should be configured.
	*/

	return lp3943_pwm_set_mode(lp3943_pwm, pwm_map, val);
	}

	static void lp3943_pwm_disable(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
	struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[pwm->hwpwm];

	/*
	* LP3943 outputs are open-drain, so the pin should be configured
	* when the PWM is disabled.
	*/

	lp3943_pwm_set_mode(lp3943_pwm, pwm_map, LP3943_GPIO_OUT_HIGH);
	}

	static int lp3943_pwm_apply(struct pwm_chip chip, struct pwm_device pwm,
	const struct pwm_state *state)
	{
	int err;

	if (state->polarity != PWM_POLARITY_NORMAL)
	return -EINVAL;

	if (!state->enabled) {
	if (pwm->state.enabled)
	lp3943_pwm_disable(chip, pwm);
	return 0;
	}

	err = lp3943_pwm_config(chip, pwm, state->duty_cycle, state->period);
	if (err)
	return err;

	if (!pwm->state.enabled)
	err = lp3943_pwm_enable(chip, pwm);

	return err;
	}

	static const struct pwm_ops lp3943_pwm_ops = {
	.request = lp3943_pwm_request,
	.free = lp3943_pwm_free,
	.apply = lp3943_pwm_apply,
	};

	static int lp3943_pwm_parse_dt(struct device *dev,
	struct lp3943_pwm *lp3943_pwm)
	{
	static const char * const name[] = { "ti,pwm0", "ti,pwm1", };
	struct device_node *node = dev->of_node;
	struct lp3943_platform_data *pdata;
	struct lp3943_pwm_map *pwm_map;
	enum lp3943_pwm_output *output;
	int i, err, num_outputs, count = 0;

	if (!node)
	return -EINVAL;

	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
	return -ENOMEM;

	/*
	* Read the output map configuration from the device tree.
	* Each of the two PWM generators can drive zero or more outputs.
	*/

	for (i = 0; i < LP3943_NUM_PWMS; i++) {
	num_outputs = of_property_count_u32_elems(node, name[i]);
	if (num_outputs <= 0)
	continue;

	output = devm_kcalloc(dev, num_outputs, sizeof(*output),
	GFP_KERNEL);
	if (!output)
	return -ENOMEM;

	err = of_property_read_u32_array(node, name[i], output,
	num_outputs);
	if (err)
	return err;

	pwm_map = devm_kzalloc(dev, sizeof(*pwm_map), GFP_KERNEL);
	if (!pwm_map)
	return -ENOMEM;

	pwm_map->output = output;
	pwm_map->num_outputs = num_outputs;
	pdata->pwms[i] = pwm_map;

	count++;
	}

	if (count == 0)
	return -ENODATA;

	lp3943_pwm->pdata = pdata;
	return 0;
	}

	static int lp3943_pwm_probe(struct platform_device *pdev)
	{
	struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
	struct pwm_chip *chip;
	struct lp3943_pwm *lp3943_pwm;
	int ret;

	chip = devm_pwmchip_alloc(&pdev->dev, LP3943_NUM_PWMS, sizeof(*lp3943_pwm));
	if (IS_ERR(chip))
	return PTR_ERR(chip);
	lp3943_pwm = to_lp3943_pwm(chip);

	lp3943_pwm->pdata = lp3943->pdata;
	if (!lp3943_pwm->pdata) {
	if (IS_ENABLED(CONFIG_OF))
	ret = lp3943_pwm_parse_dt(&pdev->dev, lp3943_pwm);
	else
	ret = -ENODEV;

	if (ret)
	return ret;
	}

	lp3943_pwm->lp3943 = lp3943;
	chip->ops = &lp3943_pwm_ops;

	return devm_pwmchip_add(&pdev->dev, chip);
	}

	#ifdef CONFIG_OF
	static const struct of_device_id lp3943_pwm_of_match[] = {
	{ .compatible = "ti,lp3943-pwm", },
	{ }
	};
	MODULE_DEVICE_TABLE(of, lp3943_pwm_of_match);
	#endif

	static struct platform_driver lp3943_pwm_driver = {
	.probe = lp3943_pwm_probe,
	.driver = {
	.name = "lp3943-pwm",
	.of_match_table = of_match_ptr(lp3943_pwm_of_match),
	},
	};
	module_platform_driver(lp3943_pwm_driver);

	MODULE_DESCRIPTION("LP3943 PWM driver");
	MODULE_ALIAS("platform:lp3943-pwm");
	MODULE_AUTHOR("Milo Kim");
	MODULE_LICENSE("GPL");