[linux-block.git] / drivers / pwm / pwm-lp3943.c

// 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/i2c.h>
#include <linux/mfd/lp3943.h>
#include <linux/module.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 pwm_chip chip;
	struct lp3943 *lp3943;
	struct lp3943_platform_data *pdata;
};

static inline struct lp3943_pwm *to_lp3943_pwm(struct pwm_chip *_chip)
{
	return container_of(_chip, struct lp3943_pwm, 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;
	int i, offset;

	pwm_map = kzalloc(sizeof(*pwm_map), GFP_KERNEL);
	if (!pwm_map)
		return ERR_PTR(-ENOMEM);

	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)) {
			kfree(pwm_map);
			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 pwm_set_chip_data(pwm, pwm_map);
}

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);
	}

	kfree(pwm_map);
}

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 = pwm_get_chip_data(pwm);

	lp3943_pwm_free_map(lp3943_pwm, pwm_map);
}

static int lp3943_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
			     int duty_ns, int 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;
	}

	period_ns = clamp(period_ns, LP3943_MIN_PERIOD, LP3943_MAX_PERIOD);
	val       = (u8)(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)(duty_ns * LP3943_MAX_DUTY / 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 = pwm_get_chip_data(pwm);
	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 = pwm_get_chip_data(pwm);

	/*
	 * 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 const struct pwm_ops lp3943_pwm_ops = {
	.request	= lp3943_pwm_request,
	.free		= lp3943_pwm_free,
	.config		= lp3943_pwm_config,
	.enable		= lp3943_pwm_enable,
	.disable	= lp3943_pwm_disable,
	.owner		= THIS_MODULE,
};

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, proplen, count = 0;
	u32 num_outputs;

	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++) {
		if (!of_get_property(node, name[i], &proplen))
			continue;

		num_outputs = proplen / sizeof(u32);
		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 lp3943_pwm *lp3943_pwm;
	int ret;

	lp3943_pwm = devm_kzalloc(&pdev->dev, sizeof(*lp3943_pwm), GFP_KERNEL);
	if (!lp3943_pwm)
		return -ENOMEM;

	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;
	lp3943_pwm->chip.dev = &pdev->dev;
	lp3943_pwm->chip.ops = &lp3943_pwm_ops;
	lp3943_pwm->chip.npwm = LP3943_NUM_PWMS;

	return devm_pwmchip_add(&pdev->dev, &lp3943_pwm->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");
Commit	Line	Data
a10e763b	1	// SPDX-License-Identifier: GPL-2.0-only
af66b3c0 MK	2	/*
	3	* TI/National Semiconductor LP3943 PWM driver
	4	*
	5	* Copyright 2013 Texas Instruments
	6	*
	7	* Author: Milo Kim <milo.kim@ti.com>
af66b3c0 MK	8	*/
	9
	10	#include <linux/err.h>
	11	#include <linux/i2c.h>
	12	#include <linux/mfd/lp3943.h>
	13	#include <linux/module.h>
	14	#include <linux/platform_device.h>
	15	#include <linux/pwm.h>
	16	#include <linux/slab.h>
	17
	18	#define LP3943_MAX_DUTY 255
	19	#define LP3943_MIN_PERIOD 6250
	20	#define LP3943_MAX_PERIOD 1600000
	21
	22	struct lp3943_pwm {
	23	struct pwm_chip chip;
	24	struct lp3943 *lp3943;
	25	struct lp3943_platform_data *pdata;
	26	};
	27
	28	static inline struct lp3943_pwm to_lp3943_pwm(struct pwm_chip _chip)
	29	{
	30	return container_of(_chip, struct lp3943_pwm, chip);
	31	}
	32
	33	static struct lp3943_pwm_map *
	34	lp3943_pwm_request_map(struct lp3943_pwm *lp3943_pwm, int hwpwm)
	35	{
	36	struct lp3943_platform_data *pdata = lp3943_pwm->pdata;
	37	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
	38	struct lp3943_pwm_map *pwm_map;
	39	int i, offset;
	40
	41	pwm_map = kzalloc(sizeof(*pwm_map), GFP_KERNEL);
	42	if (!pwm_map)
	43	return ERR_PTR(-ENOMEM);
	44
	45	pwm_map->output = pdata->pwms[hwpwm]->output;
	46	pwm_map->num_outputs = pdata->pwms[hwpwm]->num_outputs;
	47
	48	for (i = 0; i < pwm_map->num_outputs; i++) {
	49	offset = pwm_map->output[i];
	50
	51	/* Return an error if the pin is already assigned */
0b7d25c3 CE	52	if (test_and_set_bit(offset, &lp3943->pin_used)) {
0b7d25c3 CE	53	kfree(pwm_map);
af66b3c0	54	return ERR_PTR(-EBUSY);
0b7d25c3	55	}
af66b3c0 MK	56	}
	57
	58	return pwm_map;
	59	}
	60
	61	static int lp3943_pwm_request(struct pwm_chip chip, struct pwm_device pwm)
	62	{
	63	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
	64	struct lp3943_pwm_map *pwm_map;
	65
	66	pwm_map = lp3943_pwm_request_map(lp3943_pwm, pwm->hwpwm);
	67	if (IS_ERR(pwm_map))
	68	return PTR_ERR(pwm_map);
	69
	70	return pwm_set_chip_data(pwm, pwm_map);
	71	}
	72
	73	static void lp3943_pwm_free_map(struct lp3943_pwm *lp3943_pwm,
	74	struct lp3943_pwm_map *pwm_map)
	75	{
	76	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
	77	int i, offset;
	78
	79	for (i = 0; i < pwm_map->num_outputs; i++) {
	80	offset = pwm_map->output[i];
	81	clear_bit(offset, &lp3943->pin_used);
	82	}
	83
	84	kfree(pwm_map);
	85	}
	86
	87	static void lp3943_pwm_free(struct pwm_chip chip, struct pwm_device pwm)
	88	{
	89	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
	90	struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
	91
	92	lp3943_pwm_free_map(lp3943_pwm, pwm_map);
	93	}
	94
	95	static int lp3943_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
	96	int duty_ns, int period_ns)
	97	{
	98	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
	99	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
	100	u8 val, reg_duty, reg_prescale;
	101	int err;
	102
	103	/*
	104	* How to configure the LP3943 PWMs
	105	*
	106	* 1) Period = 6250 ~ 1600000
	107	* 2) Prescale = period / 6250 -1
	108	* 3) Duty = input duty
	109	*
	110	* Prescale and duty are register values
	111	*/
	112
	113	if (pwm->hwpwm == 0) {
	114	reg_prescale = LP3943_REG_PRESCALE0;
	115	reg_duty = LP3943_REG_PWM0;
	116	} else {
	117	reg_prescale = LP3943_REG_PRESCALE1;
	118	reg_duty = LP3943_REG_PWM1;
	119	}
120
121	period_ns = clamp(period_ns, LP3943_MIN_PERIOD, LP3943_MAX_PERIOD);
122	val = (u8)(period_ns / LP3943_MIN_PERIOD - 1);
123
124	err = lp3943_write_byte(lp3943, reg_prescale, val);
125	if (err)
126	return err;
127
5e3b07ca	128	duty_ns = min(duty_ns, period_ns);
af66b3c0 MK	129	val = (u8)(duty_ns * LP3943_MAX_DUTY / period_ns);
	130
	131	return lp3943_write_byte(lp3943, reg_duty, val);
	132	}
	133
	134	static int lp3943_pwm_set_mode(struct lp3943_pwm *lp3943_pwm,
	135	struct lp3943_pwm_map *pwm_map,
	136	u8 val)
	137	{
	138	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
	139	const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
	140	int i, index, err;
	141
	142	for (i = 0; i < pwm_map->num_outputs; i++) {
	143	index = pwm_map->output[i];
	144	err = lp3943_update_bits(lp3943, mux[index].reg,
	145	mux[index].mask,
	146	val << mux[index].shift);
	147	if (err)
	148	return err;
	149	}
	150
	151	return 0;
	152	}
	153
	154	static int lp3943_pwm_enable(struct pwm_chip chip, struct pwm_device pwm)
	155	{
	156	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
	157	struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
	158	u8 val;
	159
	160	if (pwm->hwpwm == 0)
	161	val = LP3943_DIM_PWM0;
	162	else
	163	val = LP3943_DIM_PWM1;
	164
	165	/*
	166	* Each PWM generator is set to control any of outputs of LP3943.
	167	* To enable/disable the PWM, these output pins should be configured.
	168	*/
	169
	170	return lp3943_pwm_set_mode(lp3943_pwm, pwm_map, val);
	171	}
	172
	173	static void lp3943_pwm_disable(struct pwm_chip chip, struct pwm_device pwm)
	174	{
	175	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
	176	struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
	177
	178	/*
	179	* LP3943 outputs are open-drain, so the pin should be configured
	180	* when the PWM is disabled.
	181	*/
	182
	183	lp3943_pwm_set_mode(lp3943_pwm, pwm_map, LP3943_GPIO_OUT_HIGH);
	184	}
	185
	186	static const struct pwm_ops lp3943_pwm_ops = {
	187	.request = lp3943_pwm_request,
	188	.free = lp3943_pwm_free,
	189	.config = lp3943_pwm_config,
	190	.enable = lp3943_pwm_enable,
	191	.disable = lp3943_pwm_disable,
	192	.owner = THIS_MODULE,
193	};
194
195	static int lp3943_pwm_parse_dt(struct device *dev,
196	struct lp3943_pwm *lp3943_pwm)
197	{
198	static const char * const name[] = { "ti,pwm0", "ti,pwm1", };
199	struct device_node *node = dev->of_node;
200	struct lp3943_platform_data *pdata;
201	struct lp3943_pwm_map *pwm_map;
202	enum lp3943_pwm_output *output;
203	int i, err, proplen, count = 0;
204	u32 num_outputs;
205
206	if (!node)
207	return -EINVAL;
208
209	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
210	if (!pdata)
211	return -ENOMEM;
212
213	/*
214	* Read the output map configuration from the device tree.
215	* Each of the two PWM generators can drive zero or more outputs.
216	*/
217
218	for (i = 0; i < LP3943_NUM_PWMS; i++) {
219	if (!of_get_property(node, name[i], &proplen))
220	continue;
221
222	num_outputs = proplen / sizeof(u32);
223	if (num_outputs == 0)
224	continue;
225
a86854d0	226	output = devm_kcalloc(dev, num_outputs, sizeof(*output),
af66b3c0 MK	227	GFP_KERNEL);
	228	if (!output)
	229	return -ENOMEM;
	230
	231	err = of_property_read_u32_array(node, name[i], output,
	232	num_outputs);
	233	if (err)
	234	return err;
	235
	236	pwm_map = devm_kzalloc(dev, sizeof(*pwm_map), GFP_KERNEL);
	237	if (!pwm_map)
	238	return -ENOMEM;
	239
	240	pwm_map->output = output;
	241	pwm_map->num_outputs = num_outputs;
	242	pdata->pwms[i] = pwm_map;
	243
	244	count++;
	245	}
	246
	247	if (count == 0)
	248	return -ENODATA;
	249
	250	lp3943_pwm->pdata = pdata;
	251	return 0;
	252	}
	253
	254	static int lp3943_pwm_probe(struct platform_device *pdev)
	255	{
	256	struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
	257	struct lp3943_pwm *lp3943_pwm;
	258	int ret;
	259
	260	lp3943_pwm = devm_kzalloc(&pdev->dev, sizeof(*lp3943_pwm), GFP_KERNEL);
	261	if (!lp3943_pwm)
	262	return -ENOMEM;
	263
	264	lp3943_pwm->pdata = lp3943->pdata;
	265	if (!lp3943_pwm->pdata) {
	266	if (IS_ENABLED(CONFIG_OF))
	267	ret = lp3943_pwm_parse_dt(&pdev->dev, lp3943_pwm);
	268	else
	269	ret = -ENODEV;
	270
	271	if (ret)
	272	return ret;
	273	}
	274
	275	lp3943_pwm->lp3943 = lp3943;
	276	lp3943_pwm->chip.dev = &pdev->dev;
	277	lp3943_pwm->chip.ops = &lp3943_pwm_ops;
	278	lp3943_pwm->chip.npwm = LP3943_NUM_PWMS;
	279
071beb7c	280	return devm_pwmchip_add(&pdev->dev, &lp3943_pwm->chip);
af66b3c0 MK	281	}
	282
	283	#ifdef CONFIG_OF
	284	static const struct of_device_id lp3943_pwm_of_match[] = {
	285	{ .compatible = "ti,lp3943-pwm", },
	286	{ }
	287	};
	288	MODULE_DEVICE_TABLE(of, lp3943_pwm_of_match);
	289	#endif
	290
	291	static struct platform_driver lp3943_pwm_driver = {
	292	.probe = lp3943_pwm_probe,
af66b3c0 MK	293	.driver = {
af66b3c0 MK	294	.name = "lp3943-pwm",
af66b3c0 MK	295	.of_match_table = of_match_ptr(lp3943_pwm_of_match),
	296	},
	297	};
	298	module_platform_driver(lp3943_pwm_driver);
	299
	300	MODULE_DESCRIPTION("LP3943 PWM driver");
	301	MODULE_ALIAS("platform:lp3943-pwm");
	302	MODULE_AUTHOR("Milo Kim");
	303	MODULE_LICENSE("GPL");