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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * TI/National Semiconductor LP3943 PWM driver
4 *
5 * Copyright 2013 Texas Instruments
6 *
7 * Author: Milo Kim <milo.kim@ti.com>
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
22struct lp3943_pwm {
23 struct pwm_chip chip;
24 struct lp3943 *lp3943;
25 struct lp3943_platform_data *pdata;
26};
27
28static inline struct lp3943_pwm *to_lp3943_pwm(struct pwm_chip *_chip)
29{
30 return container_of(_chip, struct lp3943_pwm, chip);
31}
32
33static struct lp3943_pwm_map *
34lp3943_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 */
52 if (test_and_set_bit(offset, &lp3943->pin_used)) {
53 kfree(pwm_map);
54 return ERR_PTR(-EBUSY);
55 }
56 }
57
58 return pwm_map;
59}
60
61static 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
73static 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
87static 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
95static int lp3943_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
96 u64 duty_ns, u64 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 /*
122 * Note that after this clamping, period_ns fits into an int. This is
123 * helpful because we can resort to integer division below instead of
124 * the (more expensive) 64 bit division.
125 */
126 period_ns = clamp(period_ns, (u64)LP3943_MIN_PERIOD, (u64)LP3943_MAX_PERIOD);
127 val = (u8)((int)period_ns / LP3943_MIN_PERIOD - 1);
128
129 err = lp3943_write_byte(lp3943, reg_prescale, val);
130 if (err)
131 return err;
132
133 duty_ns = min(duty_ns, period_ns);
134 val = (u8)((int)duty_ns * LP3943_MAX_DUTY / (int)period_ns);
135
136 return lp3943_write_byte(lp3943, reg_duty, val);
137}
138
139static int lp3943_pwm_set_mode(struct lp3943_pwm *lp3943_pwm,
140 struct lp3943_pwm_map *pwm_map,
141 u8 val)
142{
143 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
144 const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
145 int i, index, err;
146
147 for (i = 0; i < pwm_map->num_outputs; i++) {
148 index = pwm_map->output[i];
149 err = lp3943_update_bits(lp3943, mux[index].reg,
150 mux[index].mask,
151 val << mux[index].shift);
152 if (err)
153 return err;
154 }
155
156 return 0;
157}
158
159static int lp3943_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
160{
161 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
162 struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
163 u8 val;
164
165 if (pwm->hwpwm == 0)
166 val = LP3943_DIM_PWM0;
167 else
168 val = LP3943_DIM_PWM1;
169
170 /*
171 * Each PWM generator is set to control any of outputs of LP3943.
172 * To enable/disable the PWM, these output pins should be configured.
173 */
174
175 return lp3943_pwm_set_mode(lp3943_pwm, pwm_map, val);
176}
177
178static void lp3943_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
179{
180 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
181 struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
182
183 /*
184 * LP3943 outputs are open-drain, so the pin should be configured
185 * when the PWM is disabled.
186 */
187
188 lp3943_pwm_set_mode(lp3943_pwm, pwm_map, LP3943_GPIO_OUT_HIGH);
189}
190
191static int lp3943_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
192 const struct pwm_state *state)
193{
194 int err;
195
196 if (state->polarity != PWM_POLARITY_NORMAL)
197 return -EINVAL;
198
199 if (!state->enabled) {
200 if (pwm->state.enabled)
201 lp3943_pwm_disable(chip, pwm);
202 return 0;
203 }
204
205 err = lp3943_pwm_config(chip, pwm, state->duty_cycle, state->period);
206 if (err)
207 return err;
208
209 if (!pwm->state.enabled)
210 err = lp3943_pwm_enable(chip, pwm);
211
212 return err;
213}
214
215static const struct pwm_ops lp3943_pwm_ops = {
216 .request = lp3943_pwm_request,
217 .free = lp3943_pwm_free,
218 .apply = lp3943_pwm_apply,
219 .owner = THIS_MODULE,
220};
221
222static int lp3943_pwm_parse_dt(struct device *dev,
223 struct lp3943_pwm *lp3943_pwm)
224{
225 static const char * const name[] = { "ti,pwm0", "ti,pwm1", };
226 struct device_node *node = dev->of_node;
227 struct lp3943_platform_data *pdata;
228 struct lp3943_pwm_map *pwm_map;
229 enum lp3943_pwm_output *output;
230 int i, err, proplen, count = 0;
231 u32 num_outputs;
232
233 if (!node)
234 return -EINVAL;
235
236 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
237 if (!pdata)
238 return -ENOMEM;
239
240 /*
241 * Read the output map configuration from the device tree.
242 * Each of the two PWM generators can drive zero or more outputs.
243 */
244
245 for (i = 0; i < LP3943_NUM_PWMS; i++) {
246 if (!of_get_property(node, name[i], &proplen))
247 continue;
248
249 num_outputs = proplen / sizeof(u32);
250 if (num_outputs == 0)
251 continue;
252
253 output = devm_kcalloc(dev, num_outputs, sizeof(*output),
254 GFP_KERNEL);
255 if (!output)
256 return -ENOMEM;
257
258 err = of_property_read_u32_array(node, name[i], output,
259 num_outputs);
260 if (err)
261 return err;
262
263 pwm_map = devm_kzalloc(dev, sizeof(*pwm_map), GFP_KERNEL);
264 if (!pwm_map)
265 return -ENOMEM;
266
267 pwm_map->output = output;
268 pwm_map->num_outputs = num_outputs;
269 pdata->pwms[i] = pwm_map;
270
271 count++;
272 }
273
274 if (count == 0)
275 return -ENODATA;
276
277 lp3943_pwm->pdata = pdata;
278 return 0;
279}
280
281static int lp3943_pwm_probe(struct platform_device *pdev)
282{
283 struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
284 struct lp3943_pwm *lp3943_pwm;
285 int ret;
286
287 lp3943_pwm = devm_kzalloc(&pdev->dev, sizeof(*lp3943_pwm), GFP_KERNEL);
288 if (!lp3943_pwm)
289 return -ENOMEM;
290
291 lp3943_pwm->pdata = lp3943->pdata;
292 if (!lp3943_pwm->pdata) {
293 if (IS_ENABLED(CONFIG_OF))
294 ret = lp3943_pwm_parse_dt(&pdev->dev, lp3943_pwm);
295 else
296 ret = -ENODEV;
297
298 if (ret)
299 return ret;
300 }
301
302 lp3943_pwm->lp3943 = lp3943;
303 lp3943_pwm->chip.dev = &pdev->dev;
304 lp3943_pwm->chip.ops = &lp3943_pwm_ops;
305 lp3943_pwm->chip.npwm = LP3943_NUM_PWMS;
306
307 return devm_pwmchip_add(&pdev->dev, &lp3943_pwm->chip);
308}
309
310#ifdef CONFIG_OF
311static const struct of_device_id lp3943_pwm_of_match[] = {
312 { .compatible = "ti,lp3943-pwm", },
313 { }
314};
315MODULE_DEVICE_TABLE(of, lp3943_pwm_of_match);
316#endif
317
318static struct platform_driver lp3943_pwm_driver = {
319 .probe = lp3943_pwm_probe,
320 .driver = {
321 .name = "lp3943-pwm",
322 .of_match_table = of_match_ptr(lp3943_pwm_of_match),
323 },
324};
325module_platform_driver(lp3943_pwm_driver);
326
327MODULE_DESCRIPTION("LP3943 PWM driver");
328MODULE_ALIAS("platform:lp3943-pwm");
329MODULE_AUTHOR("Milo Kim");
330MODULE_LICENSE("GPL");
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
25struct lp3943_pwm {
26 struct pwm_chip chip;
27 struct lp3943 *lp3943;
28 struct lp3943_platform_data *pdata;
29};
30
31static inline struct lp3943_pwm *to_lp3943_pwm(struct pwm_chip *_chip)
32{
33 return container_of(_chip, struct lp3943_pwm, chip);
34}
35
36static struct lp3943_pwm_map *
37lp3943_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 kfree(pwm_map);
57 return ERR_PTR(-EBUSY);
58 }
59 }
60
61 return pwm_map;
62}
63
64static int lp3943_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
65{
66 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
67 struct lp3943_pwm_map *pwm_map;
68
69 pwm_map = lp3943_pwm_request_map(lp3943_pwm, pwm->hwpwm);
70 if (IS_ERR(pwm_map))
71 return PTR_ERR(pwm_map);
72
73 return pwm_set_chip_data(pwm, pwm_map);
74}
75
76static void lp3943_pwm_free_map(struct lp3943_pwm *lp3943_pwm,
77 struct lp3943_pwm_map *pwm_map)
78{
79 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
80 int i, offset;
81
82 for (i = 0; i < pwm_map->num_outputs; i++) {
83 offset = pwm_map->output[i];
84 clear_bit(offset, &lp3943->pin_used);
85 }
86
87 kfree(pwm_map);
88}
89
90static void lp3943_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
91{
92 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
93 struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
94
95 lp3943_pwm_free_map(lp3943_pwm, pwm_map);
96}
97
98static int lp3943_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
99 int duty_ns, int period_ns)
100{
101 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
102 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
103 u8 val, reg_duty, reg_prescale;
104 int err;
105
106 /*
107 * How to configure the LP3943 PWMs
108 *
109 * 1) Period = 6250 ~ 1600000
110 * 2) Prescale = period / 6250 -1
111 * 3) Duty = input duty
112 *
113 * Prescale and duty are register values
114 */
115
116 if (pwm->hwpwm == 0) {
117 reg_prescale = LP3943_REG_PRESCALE0;
118 reg_duty = LP3943_REG_PWM0;
119 } else {
120 reg_prescale = LP3943_REG_PRESCALE1;
121 reg_duty = LP3943_REG_PWM1;
122 }
123
124 period_ns = clamp(period_ns, LP3943_MIN_PERIOD, LP3943_MAX_PERIOD);
125 val = (u8)(period_ns / LP3943_MIN_PERIOD - 1);
126
127 err = lp3943_write_byte(lp3943, reg_prescale, val);
128 if (err)
129 return err;
130
131 val = (u8)(duty_ns * LP3943_MAX_DUTY / period_ns);
132
133 return lp3943_write_byte(lp3943, reg_duty, val);
134}
135
136static int lp3943_pwm_set_mode(struct lp3943_pwm *lp3943_pwm,
137 struct lp3943_pwm_map *pwm_map,
138 u8 val)
139{
140 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
141 const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
142 int i, index, err;
143
144 for (i = 0; i < pwm_map->num_outputs; i++) {
145 index = pwm_map->output[i];
146 err = lp3943_update_bits(lp3943, mux[index].reg,
147 mux[index].mask,
148 val << mux[index].shift);
149 if (err)
150 return err;
151 }
152
153 return 0;
154}
155
156static int lp3943_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
157{
158 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
159 struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
160 u8 val;
161
162 if (pwm->hwpwm == 0)
163 val = LP3943_DIM_PWM0;
164 else
165 val = LP3943_DIM_PWM1;
166
167 /*
168 * Each PWM generator is set to control any of outputs of LP3943.
169 * To enable/disable the PWM, these output pins should be configured.
170 */
171
172 return lp3943_pwm_set_mode(lp3943_pwm, pwm_map, val);
173}
174
175static void lp3943_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
176{
177 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
178 struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
179
180 /*
181 * LP3943 outputs are open-drain, so the pin should be configured
182 * when the PWM is disabled.
183 */
184
185 lp3943_pwm_set_mode(lp3943_pwm, pwm_map, LP3943_GPIO_OUT_HIGH);
186}
187
188static const struct pwm_ops lp3943_pwm_ops = {
189 .request = lp3943_pwm_request,
190 .free = lp3943_pwm_free,
191 .config = lp3943_pwm_config,
192 .enable = lp3943_pwm_enable,
193 .disable = lp3943_pwm_disable,
194 .owner = THIS_MODULE,
195};
196
197static int lp3943_pwm_parse_dt(struct device *dev,
198 struct lp3943_pwm *lp3943_pwm)
199{
200 static const char * const name[] = { "ti,pwm0", "ti,pwm1", };
201 struct device_node *node = dev->of_node;
202 struct lp3943_platform_data *pdata;
203 struct lp3943_pwm_map *pwm_map;
204 enum lp3943_pwm_output *output;
205 int i, err, proplen, count = 0;
206 u32 num_outputs;
207
208 if (!node)
209 return -EINVAL;
210
211 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
212 if (!pdata)
213 return -ENOMEM;
214
215 /*
216 * Read the output map configuration from the device tree.
217 * Each of the two PWM generators can drive zero or more outputs.
218 */
219
220 for (i = 0; i < LP3943_NUM_PWMS; i++) {
221 if (!of_get_property(node, name[i], &proplen))
222 continue;
223
224 num_outputs = proplen / sizeof(u32);
225 if (num_outputs == 0)
226 continue;
227
228 output = devm_kzalloc(dev, sizeof(*output) * num_outputs,
229 GFP_KERNEL);
230 if (!output)
231 return -ENOMEM;
232
233 err = of_property_read_u32_array(node, name[i], output,
234 num_outputs);
235 if (err)
236 return err;
237
238 pwm_map = devm_kzalloc(dev, sizeof(*pwm_map), GFP_KERNEL);
239 if (!pwm_map)
240 return -ENOMEM;
241
242 pwm_map->output = output;
243 pwm_map->num_outputs = num_outputs;
244 pdata->pwms[i] = pwm_map;
245
246 count++;
247 }
248
249 if (count == 0)
250 return -ENODATA;
251
252 lp3943_pwm->pdata = pdata;
253 return 0;
254}
255
256static int lp3943_pwm_probe(struct platform_device *pdev)
257{
258 struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
259 struct lp3943_pwm *lp3943_pwm;
260 int ret;
261
262 lp3943_pwm = devm_kzalloc(&pdev->dev, sizeof(*lp3943_pwm), GFP_KERNEL);
263 if (!lp3943_pwm)
264 return -ENOMEM;
265
266 lp3943_pwm->pdata = lp3943->pdata;
267 if (!lp3943_pwm->pdata) {
268 if (IS_ENABLED(CONFIG_OF))
269 ret = lp3943_pwm_parse_dt(&pdev->dev, lp3943_pwm);
270 else
271 ret = -ENODEV;
272
273 if (ret)
274 return ret;
275 }
276
277 lp3943_pwm->lp3943 = lp3943;
278 lp3943_pwm->chip.dev = &pdev->dev;
279 lp3943_pwm->chip.ops = &lp3943_pwm_ops;
280 lp3943_pwm->chip.npwm = LP3943_NUM_PWMS;
281 lp3943_pwm->chip.can_sleep = true;
282
283 platform_set_drvdata(pdev, lp3943_pwm);
284
285 return pwmchip_add(&lp3943_pwm->chip);
286}
287
288static int lp3943_pwm_remove(struct platform_device *pdev)
289{
290 struct lp3943_pwm *lp3943_pwm = platform_get_drvdata(pdev);
291
292 return pwmchip_remove(&lp3943_pwm->chip);
293}
294
295#ifdef CONFIG_OF
296static const struct of_device_id lp3943_pwm_of_match[] = {
297 { .compatible = "ti,lp3943-pwm", },
298 { }
299};
300MODULE_DEVICE_TABLE(of, lp3943_pwm_of_match);
301#endif
302
303static struct platform_driver lp3943_pwm_driver = {
304 .probe = lp3943_pwm_probe,
305 .remove = lp3943_pwm_remove,
306 .driver = {
307 .name = "lp3943-pwm",
308 .of_match_table = of_match_ptr(lp3943_pwm_of_match),
309 },
310};
311module_platform_driver(lp3943_pwm_driver);
312
313MODULE_DESCRIPTION("LP3943 PWM driver");
314MODULE_ALIAS("platform:lp3943-pwm");
315MODULE_AUTHOR("Milo Kim");
316MODULE_LICENSE("GPL");