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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/mfd/lp3943.h>
12#include <linux/module.h>
13#include <linux/of.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 struct lp3943_pwm_map pwm_map[LP3943_NUM_PWMS];
27};
28
29static inline struct lp3943_pwm *to_lp3943_pwm(struct pwm_chip *chip)
30{
31 return container_of(chip, struct lp3943_pwm, chip);
32}
33
34static struct lp3943_pwm_map *
35lp3943_pwm_request_map(struct lp3943_pwm *lp3943_pwm, int hwpwm)
36{
37 struct lp3943_platform_data *pdata = lp3943_pwm->pdata;
38 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
39 struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[hwpwm];
40 int i, offset;
41
42 pwm_map->output = pdata->pwms[hwpwm]->output;
43 pwm_map->num_outputs = pdata->pwms[hwpwm]->num_outputs;
44
45 for (i = 0; i < pwm_map->num_outputs; i++) {
46 offset = pwm_map->output[i];
47
48 /* Return an error if the pin is already assigned */
49 if (test_and_set_bit(offset, &lp3943->pin_used))
50 return ERR_PTR(-EBUSY);
51 }
52
53 return pwm_map;
54}
55
56static int lp3943_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
57{
58 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
59 struct lp3943_pwm_map *pwm_map;
60
61 pwm_map = lp3943_pwm_request_map(lp3943_pwm, pwm->hwpwm);
62 if (IS_ERR(pwm_map))
63 return PTR_ERR(pwm_map);
64
65 return 0;
66}
67
68static void lp3943_pwm_free_map(struct lp3943_pwm *lp3943_pwm,
69 struct lp3943_pwm_map *pwm_map)
70{
71 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
72 int i, offset;
73
74 for (i = 0; i < pwm_map->num_outputs; i++) {
75 offset = pwm_map->output[i];
76 clear_bit(offset, &lp3943->pin_used);
77 }
78}
79
80static void lp3943_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
81{
82 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
83 struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[pwm->hwpwm];
84
85 lp3943_pwm_free_map(lp3943_pwm, pwm_map);
86}
87
88static int lp3943_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
89 u64 duty_ns, u64 period_ns)
90{
91 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
92 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
93 u8 val, reg_duty, reg_prescale;
94 int err;
95
96 /*
97 * How to configure the LP3943 PWMs
98 *
99 * 1) Period = 6250 ~ 1600000
100 * 2) Prescale = period / 6250 -1
101 * 3) Duty = input duty
102 *
103 * Prescale and duty are register values
104 */
105
106 if (pwm->hwpwm == 0) {
107 reg_prescale = LP3943_REG_PRESCALE0;
108 reg_duty = LP3943_REG_PWM0;
109 } else {
110 reg_prescale = LP3943_REG_PRESCALE1;
111 reg_duty = LP3943_REG_PWM1;
112 }
113
114 /*
115 * Note that after this clamping, period_ns fits into an int. This is
116 * helpful because we can resort to integer division below instead of
117 * the (more expensive) 64 bit division.
118 */
119 period_ns = clamp(period_ns, (u64)LP3943_MIN_PERIOD, (u64)LP3943_MAX_PERIOD);
120 val = (u8)((int)period_ns / LP3943_MIN_PERIOD - 1);
121
122 err = lp3943_write_byte(lp3943, reg_prescale, val);
123 if (err)
124 return err;
125
126 duty_ns = min(duty_ns, period_ns);
127 val = (u8)((int)duty_ns * LP3943_MAX_DUTY / (int)period_ns);
128
129 return lp3943_write_byte(lp3943, reg_duty, val);
130}
131
132static int lp3943_pwm_set_mode(struct lp3943_pwm *lp3943_pwm,
133 struct lp3943_pwm_map *pwm_map,
134 u8 val)
135{
136 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
137 const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
138 int i, index, err;
139
140 for (i = 0; i < pwm_map->num_outputs; i++) {
141 index = pwm_map->output[i];
142 err = lp3943_update_bits(lp3943, mux[index].reg,
143 mux[index].mask,
144 val << mux[index].shift);
145 if (err)
146 return err;
147 }
148
149 return 0;
150}
151
152static int lp3943_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
153{
154 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
155 struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[pwm->hwpwm];
156 u8 val;
157
158 if (pwm->hwpwm == 0)
159 val = LP3943_DIM_PWM0;
160 else
161 val = LP3943_DIM_PWM1;
162
163 /*
164 * Each PWM generator is set to control any of outputs of LP3943.
165 * To enable/disable the PWM, these output pins should be configured.
166 */
167
168 return lp3943_pwm_set_mode(lp3943_pwm, pwm_map, val);
169}
170
171static void lp3943_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
172{
173 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
174 struct lp3943_pwm_map *pwm_map = &lp3943_pwm->pwm_map[pwm->hwpwm];
175
176 /*
177 * LP3943 outputs are open-drain, so the pin should be configured
178 * when the PWM is disabled.
179 */
180
181 lp3943_pwm_set_mode(lp3943_pwm, pwm_map, LP3943_GPIO_OUT_HIGH);
182}
183
184static int lp3943_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
185 const struct pwm_state *state)
186{
187 int err;
188
189 if (state->polarity != PWM_POLARITY_NORMAL)
190 return -EINVAL;
191
192 if (!state->enabled) {
193 if (pwm->state.enabled)
194 lp3943_pwm_disable(chip, pwm);
195 return 0;
196 }
197
198 err = lp3943_pwm_config(chip, pwm, state->duty_cycle, state->period);
199 if (err)
200 return err;
201
202 if (!pwm->state.enabled)
203 err = lp3943_pwm_enable(chip, pwm);
204
205 return err;
206}
207
208static const struct pwm_ops lp3943_pwm_ops = {
209 .request = lp3943_pwm_request,
210 .free = lp3943_pwm_free,
211 .apply = lp3943_pwm_apply,
212};
213
214static int lp3943_pwm_parse_dt(struct device *dev,
215 struct lp3943_pwm *lp3943_pwm)
216{
217 static const char * const name[] = { "ti,pwm0", "ti,pwm1", };
218 struct device_node *node = dev->of_node;
219 struct lp3943_platform_data *pdata;
220 struct lp3943_pwm_map *pwm_map;
221 enum lp3943_pwm_output *output;
222 int i, err, proplen, count = 0;
223 u32 num_outputs;
224
225 if (!node)
226 return -EINVAL;
227
228 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
229 if (!pdata)
230 return -ENOMEM;
231
232 /*
233 * Read the output map configuration from the device tree.
234 * Each of the two PWM generators can drive zero or more outputs.
235 */
236
237 for (i = 0; i < LP3943_NUM_PWMS; i++) {
238 if (!of_get_property(node, name[i], &proplen))
239 continue;
240
241 num_outputs = proplen / sizeof(u32);
242 if (num_outputs == 0)
243 continue;
244
245 output = devm_kcalloc(dev, num_outputs, sizeof(*output),
246 GFP_KERNEL);
247 if (!output)
248 return -ENOMEM;
249
250 err = of_property_read_u32_array(node, name[i], output,
251 num_outputs);
252 if (err)
253 return err;
254
255 pwm_map = devm_kzalloc(dev, sizeof(*pwm_map), GFP_KERNEL);
256 if (!pwm_map)
257 return -ENOMEM;
258
259 pwm_map->output = output;
260 pwm_map->num_outputs = num_outputs;
261 pdata->pwms[i] = pwm_map;
262
263 count++;
264 }
265
266 if (count == 0)
267 return -ENODATA;
268
269 lp3943_pwm->pdata = pdata;
270 return 0;
271}
272
273static int lp3943_pwm_probe(struct platform_device *pdev)
274{
275 struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
276 struct lp3943_pwm *lp3943_pwm;
277 int ret;
278
279 lp3943_pwm = devm_kzalloc(&pdev->dev, sizeof(*lp3943_pwm), GFP_KERNEL);
280 if (!lp3943_pwm)
281 return -ENOMEM;
282
283 lp3943_pwm->pdata = lp3943->pdata;
284 if (!lp3943_pwm->pdata) {
285 if (IS_ENABLED(CONFIG_OF))
286 ret = lp3943_pwm_parse_dt(&pdev->dev, lp3943_pwm);
287 else
288 ret = -ENODEV;
289
290 if (ret)
291 return ret;
292 }
293
294 lp3943_pwm->lp3943 = lp3943;
295 lp3943_pwm->chip.dev = &pdev->dev;
296 lp3943_pwm->chip.ops = &lp3943_pwm_ops;
297 lp3943_pwm->chip.npwm = LP3943_NUM_PWMS;
298
299 return devm_pwmchip_add(&pdev->dev, &lp3943_pwm->chip);
300}
301
302#ifdef CONFIG_OF
303static const struct of_device_id lp3943_pwm_of_match[] = {
304 { .compatible = "ti,lp3943-pwm", },
305 { }
306};
307MODULE_DEVICE_TABLE(of, lp3943_pwm_of_match);
308#endif
309
310static struct platform_driver lp3943_pwm_driver = {
311 .probe = lp3943_pwm_probe,
312 .driver = {
313 .name = "lp3943-pwm",
314 .of_match_table = of_match_ptr(lp3943_pwm_of_match),
315 },
316};
317module_platform_driver(lp3943_pwm_driver);
318
319MODULE_DESCRIPTION("LP3943 PWM driver");
320MODULE_ALIAS("platform:lp3943-pwm");
321MODULE_AUTHOR("Milo Kim");
322MODULE_LICENSE("GPL");
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");