drivers/pwm/pwm-twl-led.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
  *
  * Copyright (C) 2012 Texas Instruments
  * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
  *
  * This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
  * Hemanth V <hemanthv@ti.com>
  *
  * Reference manual for the twl6030 is available at:
  * https://www.ti.com/lit/ds/symlink/twl6030.pdf
  *
  * Limitations:
  * - The twl6030 hardware only supports two period lengths (128 clock ticks and
  *   64 clock ticks), the driver only uses 128 ticks
  * - The hardware doesn't support ON = 0, so the active part of a period doesn't
  *   start at its beginning.
  * - The hardware could support inverted polarity (with a similar limitation as
  *   for normal: the last clock tick is always inactive).
  * - The hardware emits a constant low output when disabled.
  * - A request for .duty_cycle = 0 results in an output wave with one active
  *   clock tick per period. This should better use the disabled state.
  * - The driver only implements setting the relative duty cycle.
  * - The driver doesn't implement .get_state().
  */

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

 /*
  * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
  * To generate the signal on TWL4030:
  *  - LEDA uses PWMA
  *  - LEDB uses PWMB
  * TWL6030 has one LED pin with dedicated LEDPWM
  */

 #define TWL4030_LED_MAX		0x7f
 #define TWL6030_LED_MAX		0xff

 /* Registers, bits and macro for TWL4030 */
 #define TWL4030_LEDEN_REG	0x00
 #define TWL4030_PWMA_REG	0x01

 #define TWL4030_LEDXON		(1 << 0)
 #define TWL4030_LEDXPWM		(1 << 4)
 #define TWL4030_LED_PINS	(TWL4030_LEDXON | TWL4030_LEDXPWM)
 #define TWL4030_LED_TOGGLE(led, x)	((x) << (led))

 /* Register, bits and macro for TWL6030 */
 #define TWL6030_LED_PWM_CTRL1	0xf4
 #define TWL6030_LED_PWM_CTRL2	0xf5

 #define TWL6040_LED_MODE_HW	0x00
 #define TWL6040_LED_MODE_ON	0x01
 #define TWL6040_LED_MODE_OFF	0x02
 #define TWL6040_LED_MODE_MASK	0x03

 struct twl_pwmled_chip {
 	struct pwm_chip chip;
 	struct mutex mutex;
 };

 static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
 {
 	return container_of(chip, struct twl_pwmled_chip, chip);
 }

 static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			      int duty_ns, int period_ns)
 {
 	int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
 	u8 pwm_config[2] = { 1, 0 };
 	int base, ret;

 	/*
 	 * To configure the duty period:
 	 * On-cycle is set to 1 (the minimum allowed value)
 	 * The off time of 0 is not configurable, so the mapping is:
 	 * 0 -> off cycle = 2,
 	 * 1 -> off cycle = 2,
 	 * 2 -> off cycle = 3,
 	 * 126 - > off cycle 127,
 	 * 127 - > off cycle 1
 	 * When on cycle == off cycle the PWM will be always on
 	 */
 	if (duty_cycle == 1)
 		duty_cycle = 2;
 	else if (duty_cycle > TWL4030_LED_MAX)
 		duty_cycle = 1;

 	base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;

 	pwm_config[1] = duty_cycle;

 	ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
 	if (ret < 0)
 		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);

 	return ret;
 }

 static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct twl_pwmled_chip *twl = to_twl(chip);
 	int ret;
 	u8 val;

 	mutex_lock(&twl->mutex);
 	ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
 	if (ret < 0) {
 		dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
 		goto out;
 	}

 	val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);

 	ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
 	if (ret < 0)
 		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);

 out:
 	mutex_unlock(&twl->mutex);
 	return ret;
 }

 static void twl4030_pwmled_disable(struct pwm_chip *chip,
 				   struct pwm_device *pwm)
 {
 	struct twl_pwmled_chip *twl = to_twl(chip);
 	int ret;
 	u8 val;

 	mutex_lock(&twl->mutex);
 	ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
 	if (ret < 0) {
 		dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
 		goto out;
 	}

 	val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);

 	ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
 	if (ret < 0)
 		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);

 out:
 	mutex_unlock(&twl->mutex);
 }

 static int twl4030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 				const struct pwm_state *state)
 {
 	int ret;

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

 	if (!state->enabled) {
 		if (pwm->state.enabled)
 			twl4030_pwmled_disable(chip, pwm);

 		return 0;
 	}

 	/*
 	 * We cannot skip calling ->config even if state->period ==
 	 * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle
 	 * because we might have exited early in the last call to
 	 * pwm_apply_might_sleep because of !state->enabled and so the two values in
 	 * pwm->state might not be configured in hardware.
 	 */
 	ret = twl4030_pwmled_config(chip, pwm,
 				    state->duty_cycle, state->period);
 	if (ret)
 		return ret;

 	if (!pwm->state.enabled)
 		ret = twl4030_pwmled_enable(chip, pwm);

 	return ret;
 }


 static const struct pwm_ops twl4030_pwmled_ops = {
 	.apply = twl4030_pwmled_apply,
 };

 static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			      int duty_ns, int period_ns)
 {
 	int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
 	u8 on_time;
 	int ret;

 	on_time = duty_cycle & 0xff;

 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
 			       TWL6030_LED_PWM_CTRL1);
 	if (ret < 0)
 		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);

 	return ret;
 }

 static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct twl_pwmled_chip *twl = to_twl(chip);
 	int ret;
 	u8 val;

 	mutex_lock(&twl->mutex);
 	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 	if (ret < 0) {
 		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 			pwm->label);
 		goto out;
 	}

 	val &= ~TWL6040_LED_MODE_MASK;
 	val |= TWL6040_LED_MODE_ON;

 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 	if (ret < 0)
 		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);

 out:
 	mutex_unlock(&twl->mutex);
 	return ret;
 }

 static void twl6030_pwmled_disable(struct pwm_chip *chip,
 				   struct pwm_device *pwm)
 {
 	struct twl_pwmled_chip *twl = to_twl(chip);
 	int ret;
 	u8 val;

 	mutex_lock(&twl->mutex);
 	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 	if (ret < 0) {
 		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 			pwm->label);
 		goto out;
 	}

 	val &= ~TWL6040_LED_MODE_MASK;
 	val |= TWL6040_LED_MODE_OFF;

 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 	if (ret < 0)
 		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);

 out:
 	mutex_unlock(&twl->mutex);
 }

 static int twl6030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 				const struct pwm_state *state)
 {
 	int err;

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

 	if (!state->enabled) {
 		if (pwm->state.enabled)
 			twl6030_pwmled_disable(chip, pwm);

 		return 0;
 	}

 	err = twl6030_pwmled_config(chip, pwm,
 				    state->duty_cycle, state->period);
 	if (err)
 		return err;

 	if (!pwm->state.enabled)
 		err = twl6030_pwmled_enable(chip, pwm);

 	return err;
 }

 static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct twl_pwmled_chip *twl = to_twl(chip);
 	int ret;
 	u8 val;

 	mutex_lock(&twl->mutex);
 	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 	if (ret < 0) {
 		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 			pwm->label);
 		goto out;
 	}

 	val &= ~TWL6040_LED_MODE_MASK;
 	val |= TWL6040_LED_MODE_OFF;

 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 	if (ret < 0)
 		dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);

 out:
 	mutex_unlock(&twl->mutex);
 	return ret;
 }

 static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct twl_pwmled_chip *twl = to_twl(chip);
 	int ret;
 	u8 val;

 	mutex_lock(&twl->mutex);
 	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 	if (ret < 0) {
 		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 			pwm->label);
 		goto out;
 	}

 	val &= ~TWL6040_LED_MODE_MASK;
 	val |= TWL6040_LED_MODE_HW;

 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 	if (ret < 0)
 		dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);

 out:
 	mutex_unlock(&twl->mutex);
 }

 static const struct pwm_ops twl6030_pwmled_ops = {
 	.apply = twl6030_pwmled_apply,
 	.request = twl6030_pwmled_request,
 	.free = twl6030_pwmled_free,
 };

 static int twl_pwmled_probe(struct platform_device *pdev)
 {
 	struct twl_pwmled_chip *twl;

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

 	if (twl_class_is_4030()) {
 		twl->chip.ops = &twl4030_pwmled_ops;
 		twl->chip.npwm = 2;
 	} else {
 		twl->chip.ops = &twl6030_pwmled_ops;
 		twl->chip.npwm = 1;
 	}

 	twl->chip.dev = &pdev->dev;

 	mutex_init(&twl->mutex);

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

 #ifdef CONFIG_OF
 static const struct of_device_id twl_pwmled_of_match[] = {
 	{ .compatible = "ti,twl4030-pwmled" },
 	{ .compatible = "ti,twl6030-pwmled" },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
 #endif

 static struct platform_driver twl_pwmled_driver = {
 	.driver = {
 		.name = "twl-pwmled",
 		.of_match_table = of_match_ptr(twl_pwmled_of_match),
 	},
 	.probe = twl_pwmled_probe,
 };
 module_platform_driver(twl_pwmled_driver);

 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
 MODULE_ALIAS("platform:twl-pwmled");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
	*
	* Copyright (C) 2012 Texas Instruments
	* Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
	*
	* This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
	* Hemanth V <hemanthv@ti.com>
	*
	* Reference manual for the twl6030 is available at:
	* https://www.ti.com/lit/ds/symlink/twl6030.pdf
	*
	* Limitations:
	* - The twl6030 hardware only supports two period lengths (128 clock ticks and
	* 64 clock ticks), the driver only uses 128 ticks
	* - The hardware doesn't support ON = 0, so the active part of a period doesn't
	* start at its beginning.
	* - The hardware could support inverted polarity (with a similar limitation as
	* for normal: the last clock tick is always inactive).
	* - The hardware emits a constant low output when disabled.
	* - A request for .duty_cycle = 0 results in an output wave with one active
	* clock tick per period. This should better use the disabled state.
	* - The driver only implements setting the relative duty cycle.
	* - The driver doesn't implement .get_state().
	*/

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

	/*
	* This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
	* To generate the signal on TWL4030:
	* - LEDA uses PWMA
	* - LEDB uses PWMB
	* TWL6030 has one LED pin with dedicated LEDPWM
	*/

	#define TWL4030_LED_MAX 0x7f
	#define TWL6030_LED_MAX 0xff

	/* Registers, bits and macro for TWL4030 */
	#define TWL4030_LEDEN_REG 0x00
	#define TWL4030_PWMA_REG 0x01

	#define TWL4030_LEDXON (1 << 0)
	#define TWL4030_LEDXPWM (1 << 4)
	#define TWL4030_LED_PINS (TWL4030_LEDXON \| TWL4030_LEDXPWM)
	#define TWL4030_LED_TOGGLE(led, x) ((x) << (led))

	/* Register, bits and macro for TWL6030 */
	#define TWL6030_LED_PWM_CTRL1 0xf4
	#define TWL6030_LED_PWM_CTRL2 0xf5

	#define TWL6040_LED_MODE_HW 0x00
	#define TWL6040_LED_MODE_ON 0x01
	#define TWL6040_LED_MODE_OFF 0x02
	#define TWL6040_LED_MODE_MASK 0x03

	struct twl_pwmled_chip {
	struct pwm_chip chip;
	struct mutex mutex;
	};

	static inline struct twl_pwmled_chip to_twl(struct pwm_chip chip)
	{
	return container_of(chip, struct twl_pwmled_chip, chip);
	}

	static int twl4030_pwmled_config(struct pwm_chip chip, struct pwm_device pwm,
	int duty_ns, int period_ns)
	{
	int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
	u8 pwm_config[2] = { 1, 0 };
	int base, ret;

	/*
	* To configure the duty period:
	* On-cycle is set to 1 (the minimum allowed value)
	* The off time of 0 is not configurable, so the mapping is:
	* 0 -> off cycle = 2,
	* 1 -> off cycle = 2,
	* 2 -> off cycle = 3,
	* 126 - > off cycle 127,
	* 127 - > off cycle 1
	* When on cycle == off cycle the PWM will be always on
	*/
	if (duty_cycle == 1)
	duty_cycle = 2;
	else if (duty_cycle > TWL4030_LED_MAX)
	duty_cycle = 1;

	base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;

	pwm_config[1] = duty_cycle;

	ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
	if (ret < 0)
	dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);

	return ret;
	}

	static int twl4030_pwmled_enable(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
	if (ret < 0) {
	dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
	goto out;
	}

	val \|= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);

	ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
	if (ret < 0)
	dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);

	out:
	mutex_unlock(&twl->mutex);
	return ret;
	}

	static void twl4030_pwmled_disable(struct pwm_chip *chip,
	struct pwm_device *pwm)
	{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
	if (ret < 0) {
	dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
	goto out;
	}

	val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);

	ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
	if (ret < 0)
	dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);

	out:
	mutex_unlock(&twl->mutex);
	}

	static int twl4030_pwmled_apply(struct pwm_chip chip, struct pwm_device pwm,
	const struct pwm_state *state)
	{
	int ret;

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

	if (!state->enabled) {
	if (pwm->state.enabled)
	twl4030_pwmled_disable(chip, pwm);

	return 0;
	}

	/*
	* We cannot skip calling ->config even if state->period ==
	* pwm->state.period && state->duty_cycle == pwm->state.duty_cycle
	* because we might have exited early in the last call to
	* pwm_apply_might_sleep because of !state->enabled and so the two values in
	* pwm->state might not be configured in hardware.
	*/
	ret = twl4030_pwmled_config(chip, pwm,
	state->duty_cycle, state->period);
	if (ret)
	return ret;

	if (!pwm->state.enabled)
	ret = twl4030_pwmled_enable(chip, pwm);

	return ret;
	}


	static const struct pwm_ops twl4030_pwmled_ops = {
	.apply = twl4030_pwmled_apply,
	};

	static int twl6030_pwmled_config(struct pwm_chip chip, struct pwm_device pwm,
	int duty_ns, int period_ns)
	{
	int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
	u8 on_time;
	int ret;

	on_time = duty_cycle & 0xff;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
	TWL6030_LED_PWM_CTRL1);
	if (ret < 0)
	dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);

	return ret;
	}

	static int twl6030_pwmled_enable(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0) {
	dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
	pwm->label);
	goto out;
	}

	val &= ~TWL6040_LED_MODE_MASK;
	val \|= TWL6040_LED_MODE_ON;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0)
	dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);

	out:
	mutex_unlock(&twl->mutex);
	return ret;
	}

	static void twl6030_pwmled_disable(struct pwm_chip *chip,
	struct pwm_device *pwm)
	{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0) {
	dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
	pwm->label);
	goto out;
	}

	val &= ~TWL6040_LED_MODE_MASK;
	val \|= TWL6040_LED_MODE_OFF;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0)
	dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);

	out:
	mutex_unlock(&twl->mutex);
	}

	static int twl6030_pwmled_apply(struct pwm_chip chip, struct pwm_device pwm,
	const struct pwm_state *state)
	{
	int err;

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

	if (!state->enabled) {
	if (pwm->state.enabled)
	twl6030_pwmled_disable(chip, pwm);

	return 0;
	}

	err = twl6030_pwmled_config(chip, pwm,
	state->duty_cycle, state->period);
	if (err)
	return err;

	if (!pwm->state.enabled)
	err = twl6030_pwmled_enable(chip, pwm);

	return err;
	}

	static int twl6030_pwmled_request(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0) {
	dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
	pwm->label);
	goto out;
	}

	val &= ~TWL6040_LED_MODE_MASK;
	val \|= TWL6040_LED_MODE_OFF;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0)
	dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);

	out:
	mutex_unlock(&twl->mutex);
	return ret;
	}

	static void twl6030_pwmled_free(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0) {
	dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
	pwm->label);
	goto out;
	}

	val &= ~TWL6040_LED_MODE_MASK;
	val \|= TWL6040_LED_MODE_HW;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0)
	dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);

	out:
	mutex_unlock(&twl->mutex);
	}

	static const struct pwm_ops twl6030_pwmled_ops = {
	.apply = twl6030_pwmled_apply,
	.request = twl6030_pwmled_request,
	.free = twl6030_pwmled_free,
	};

	static int twl_pwmled_probe(struct platform_device *pdev)
	{
	struct twl_pwmled_chip *twl;

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

	if (twl_class_is_4030()) {
	twl->chip.ops = &twl4030_pwmled_ops;
	twl->chip.npwm = 2;
	} else {
	twl->chip.ops = &twl6030_pwmled_ops;
	twl->chip.npwm = 1;
	}

	twl->chip.dev = &pdev->dev;

	mutex_init(&twl->mutex);

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

	#ifdef CONFIG_OF
	static const struct of_device_id twl_pwmled_of_match[] = {
	{ .compatible = "ti,twl4030-pwmled" },
	{ .compatible = "ti,twl6030-pwmled" },
	{ },
	};
	MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
	#endif

	static struct platform_driver twl_pwmled_driver = {
	.driver = {
	.name = "twl-pwmled",
	.of_match_table = of_match_ptr(twl_pwmled_of_match),
	},
	.probe = twl_pwmled_probe,
	};
	module_platform_driver(twl_pwmled_driver);

	MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
	MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
	MODULE_ALIAS("platform:twl-pwmled");
	MODULE_LICENSE("GPL");