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

/*
 * TI/National Semiconductor LP3943 PWM driver
 *
 * Copyright 2013 Texas Instruments
 *
 * Author: Milo Kim <milo.kim@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.
 */

#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))
			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;

	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_kzalloc(dev, sizeof(*output) * num_outputs,
				      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;

	platform_set_drvdata(pdev, lp3943_pwm);

	return pwmchip_add(&lp3943_pwm->chip);
}

static int lp3943_pwm_remove(struct platform_device *pdev)
{
	struct lp3943_pwm *lp3943_pwm = platform_get_drvdata(pdev);

	return pwmchip_remove(&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,
	.remove = lp3943_pwm_remove,
	.driver = {
		.name = "lp3943-pwm",
		.owner = THIS_MODULE,
		.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
af66b3c0 MK	1	/*
	2	* TI/National Semiconductor LP3943 PWM driver
	3	*
	4	* Copyright 2013 Texas Instruments
	5	*
	6	* Author: Milo Kim <milo.kim@ti.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; version 2.
	11	*/
	12
	13	#include <linux/err.h>
	14	#include <linux/i2c.h>
	15	#include <linux/mfd/lp3943.h>
	16	#include <linux/module.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/pwm.h>
	19	#include <linux/slab.h>
	20
	21	#define LP3943_MAX_DUTY 255
	22	#define LP3943_MIN_PERIOD 6250
	23	#define LP3943_MAX_PERIOD 1600000
	24
	25	struct lp3943_pwm {
	26	struct pwm_chip chip;
	27	struct lp3943 *lp3943;
	28	struct lp3943_platform_data *pdata;
	29	};
	30
	31	static inline struct lp3943_pwm to_lp3943_pwm(struct pwm_chip _chip)
	32	{
	33	return container_of(_chip, struct lp3943_pwm, chip);
	34	}
	35
	36	static struct lp3943_pwm_map *
	37	lp3943_pwm_request_map(struct lp3943_pwm *lp3943_pwm, int hwpwm)
	38	{
	39	struct lp3943_platform_data *pdata = lp3943_pwm->pdata;
	40	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
	41	struct lp3943_pwm_map *pwm_map;
	42	int i, offset;
	43
	44	pwm_map = kzalloc(sizeof(*pwm_map), GFP_KERNEL);
	45	if (!pwm_map)
	46	return ERR_PTR(-ENOMEM);
	47
	48	pwm_map->output = pdata->pwms[hwpwm]->output;
	49	pwm_map->num_outputs = pdata->pwms[hwpwm]->num_outputs;
	50
	51	for (i = 0; i < pwm_map->num_outputs; i++) {
	52	offset = pwm_map->output[i];
	53
	54	/* Return an error if the pin is already assigned */
	55	if (test_and_set_bit(offset, &lp3943->pin_used))
	56	return ERR_PTR(-EBUSY);
	57	}
	58
	59	return pwm_map;
	60	}
	61
	62	static int lp3943_pwm_request(struct pwm_chip chip, struct pwm_device pwm)
	63	{
	64	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
65	struct lp3943_pwm_map *pwm_map;
66
67	pwm_map = lp3943_pwm_request_map(lp3943_pwm, pwm->hwpwm);
68	if (IS_ERR(pwm_map))
69	return PTR_ERR(pwm_map);
70
71	return pwm_set_chip_data(pwm, pwm_map);
72	}
73
74	static void lp3943_pwm_free_map(struct lp3943_pwm *lp3943_pwm,
75	struct lp3943_pwm_map *pwm_map)
76	{
77	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
78	int i, offset;
79
80	for (i = 0; i < pwm_map->num_outputs; i++) {
81	offset = pwm_map->output[i];
82	clear_bit(offset, &lp3943->pin_used);
83	}
84
85	kfree(pwm_map);
86	}
87
88	static void lp3943_pwm_free(struct pwm_chip chip, struct pwm_device pwm)
89	{
90	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
91	struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
92
93	lp3943_pwm_free_map(lp3943_pwm, pwm_map);
94	}
95
96	static int lp3943_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
97	int duty_ns, int period_ns)
98	{
99	struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
100	struct lp3943 *lp3943 = lp3943_pwm->lp3943;
101	u8 val, reg_duty, reg_prescale;
102	int err;
103
104	/*
105	* How to configure the LP3943 PWMs
106	*
107	* 1) Period = 6250 ~ 1600000
108	* 2) Prescale = period / 6250 -1
109	* 3) Duty = input duty
110	*
111	* Prescale and duty are register values
112	*/
113
114	if (pwm->hwpwm == 0) {
115	reg_prescale = LP3943_REG_PRESCALE0;
116	reg_duty = LP3943_REG_PWM0;
117	} else {
118	reg_prescale = LP3943_REG_PRESCALE1;
119	reg_duty = LP3943_REG_PWM1;
120	}
121
122	period_ns = clamp(period_ns, LP3943_MIN_PERIOD, LP3943_MAX_PERIOD);
123	val = (u8)(period_ns / LP3943_MIN_PERIOD - 1);
124
125	err = lp3943_write_byte(lp3943, reg_prescale, val);
126	if (err)
127	return err;
128
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
226	output = devm_kzalloc(dev, sizeof(output) num_outputs,
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
280	platform_set_drvdata(pdev, lp3943_pwm);
281
282	return pwmchip_add(&lp3943_pwm->chip);
283	}
284
285	static int lp3943_pwm_remove(struct platform_device *pdev)
286	{
287	struct lp3943_pwm *lp3943_pwm = platform_get_drvdata(pdev);
288
289	return pwmchip_remove(&lp3943_pwm->chip);
290	}
291
292	#ifdef CONFIG_OF
293	static const struct of_device_id lp3943_pwm_of_match[] = {
294	{ .compatible = "ti,lp3943-pwm", },
295	{ }
296	};
297	MODULE_DEVICE_TABLE(of, lp3943_pwm_of_match);
298	#endif
299
300	static struct platform_driver lp3943_pwm_driver = {
301	.probe = lp3943_pwm_probe,
302	.remove = lp3943_pwm_remove,
303	.driver = {
304	.name = "lp3943-pwm",
305	.owner = THIS_MODULE,
306	.of_match_table = of_match_ptr(lp3943_pwm_of_match),
307	},
308	};
309	module_platform_driver(lp3943_pwm_driver);
310
311	MODULE_DESCRIPTION("LP3943 PWM driver");
312	MODULE_ALIAS("platform:lp3943-pwm");
313	MODULE_AUTHOR("Milo Kim");
314	MODULE_LICENSE("GPL");