Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
aa66cc66 CZ |
2 | /* |
3 | * Regulator driver for PWM Regulators | |
4 | * | |
5 | * Copyright (C) 2014 - STMicroelectronics Inc. | |
6 | * | |
7 | * Author: Lee Jones <lee.jones@linaro.org> | |
aa66cc66 CZ |
8 | */ |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/err.h> | |
045a44d4 | 13 | #include <linux/platform_device.h> |
aa66cc66 CZ |
14 | #include <linux/regulator/driver.h> |
15 | #include <linux/regulator/machine.h> | |
16 | #include <linux/regulator/of_regulator.h> | |
17 | #include <linux/of.h> | |
aa66cc66 | 18 | #include <linux/pwm.h> |
27bfa889 | 19 | #include <linux/gpio/consumer.h> |
aa66cc66 | 20 | |
ea398e28 BB |
21 | struct pwm_continuous_reg_data { |
22 | unsigned int min_uV_dutycycle; | |
23 | unsigned int max_uV_dutycycle; | |
24 | unsigned int dutycycle_unit; | |
25 | }; | |
26 | ||
aa66cc66 | 27 | struct pwm_regulator_data { |
4773be18 | 28 | /* Shared */ |
aa66cc66 | 29 | struct pwm_device *pwm; |
4773be18 LJ |
30 | |
31 | /* Voltage table */ | |
32 | struct pwm_voltages *duty_cycle_table; | |
f907a0a9 | 33 | |
ea398e28 BB |
34 | /* Continuous mode info */ |
35 | struct pwm_continuous_reg_data continuous; | |
36 | ||
f907a0a9 LD |
37 | /* regulator descriptor */ |
38 | struct regulator_desc desc; | |
39 | ||
aa66cc66 | 40 | int state; |
4773be18 | 41 | |
27bfa889 AC |
42 | /* Enable GPIO */ |
43 | struct gpio_desc *enb_gpio; | |
aa66cc66 CZ |
44 | }; |
45 | ||
46 | struct pwm_voltages { | |
47 | unsigned int uV; | |
48 | unsigned int dutycycle; | |
49 | }; | |
50 | ||
4e773e73 | 51 | /* |
4773be18 LJ |
52 | * Voltage table call-backs |
53 | */ | |
87248991 BB |
54 | static void pwm_regulator_init_state(struct regulator_dev *rdev) |
55 | { | |
56 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); | |
57 | struct pwm_state pwm_state; | |
58 | unsigned int dutycycle; | |
59 | int i; | |
60 | ||
61 | pwm_get_state(drvdata->pwm, &pwm_state); | |
62 | dutycycle = pwm_get_relative_duty_cycle(&pwm_state, 100); | |
63 | ||
64 | for (i = 0; i < rdev->desc->n_voltages; i++) { | |
65 | if (dutycycle == drvdata->duty_cycle_table[i].dutycycle) { | |
66 | drvdata->state = i; | |
67 | return; | |
68 | } | |
69 | } | |
70 | } | |
71 | ||
ab101e35 | 72 | static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev) |
aa66cc66 | 73 | { |
ab101e35 | 74 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
aa66cc66 | 75 | |
87248991 BB |
76 | if (drvdata->state < 0) |
77 | pwm_regulator_init_state(rdev); | |
78 | ||
aa66cc66 CZ |
79 | return drvdata->state; |
80 | } | |
81 | ||
ab101e35 | 82 | static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev, |
aa66cc66 CZ |
83 | unsigned selector) |
84 | { | |
ab101e35 | 85 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
3f4eb39b | 86 | struct pwm_state pstate; |
aa66cc66 CZ |
87 | int ret; |
88 | ||
3f4eb39b BB |
89 | pwm_init_state(drvdata->pwm, &pstate); |
90 | pwm_set_relative_duty_cycle(&pstate, | |
91 | drvdata->duty_cycle_table[selector].dutycycle, 100); | |
aa66cc66 | 92 | |
c748a6d7 | 93 | ret = pwm_apply_might_sleep(drvdata->pwm, &pstate); |
aa66cc66 | 94 | if (ret) { |
5bf59bd5 | 95 | dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); |
aa66cc66 CZ |
96 | return ret; |
97 | } | |
98 | ||
99 | drvdata->state = selector; | |
100 | ||
aa66cc66 CZ |
101 | return 0; |
102 | } | |
103 | ||
ab101e35 | 104 | static int pwm_regulator_list_voltage(struct regulator_dev *rdev, |
aa66cc66 CZ |
105 | unsigned selector) |
106 | { | |
ab101e35 | 107 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
aa66cc66 | 108 | |
ab101e35 | 109 | if (selector >= rdev->desc->n_voltages) |
aa66cc66 CZ |
110 | return -EINVAL; |
111 | ||
112 | return drvdata->duty_cycle_table[selector].uV; | |
113 | } | |
4773be18 | 114 | |
1de7d802 BB |
115 | static int pwm_regulator_enable(struct regulator_dev *dev) |
116 | { | |
117 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
118 | ||
a4aae5af | 119 | gpiod_set_value_cansleep(drvdata->enb_gpio, 1); |
27bfa889 | 120 | |
1de7d802 BB |
121 | return pwm_enable(drvdata->pwm); |
122 | } | |
123 | ||
124 | static int pwm_regulator_disable(struct regulator_dev *dev) | |
125 | { | |
126 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
127 | ||
128 | pwm_disable(drvdata->pwm); | |
129 | ||
a4aae5af | 130 | gpiod_set_value_cansleep(drvdata->enb_gpio, 0); |
27bfa889 | 131 | |
1de7d802 BB |
132 | return 0; |
133 | } | |
134 | ||
135 | static int pwm_regulator_is_enabled(struct regulator_dev *dev) | |
136 | { | |
137 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
138 | ||
27bfa889 AC |
139 | if (drvdata->enb_gpio && !gpiod_get_value_cansleep(drvdata->enb_gpio)) |
140 | return false; | |
141 | ||
1de7d802 BB |
142 | return pwm_is_enabled(drvdata->pwm); |
143 | } | |
144 | ||
4773be18 LJ |
145 | static int pwm_regulator_get_voltage(struct regulator_dev *rdev) |
146 | { | |
147 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); | |
ea398e28 BB |
148 | unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle; |
149 | unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle; | |
150 | unsigned int duty_unit = drvdata->continuous.dutycycle_unit; | |
d9070fdb | 151 | int min_uV = rdev->constraints->min_uV; |
ea398e28 BB |
152 | int max_uV = rdev->constraints->max_uV; |
153 | int diff_uV = max_uV - min_uV; | |
d9070fdb | 154 | struct pwm_state pstate; |
ea398e28 BB |
155 | unsigned int diff_duty; |
156 | unsigned int voltage; | |
4773be18 | 157 | |
d9070fdb BB |
158 | pwm_get_state(drvdata->pwm, &pstate); |
159 | ||
6a7d11ef MB |
160 | if (!pstate.enabled) { |
161 | if (pstate.polarity == PWM_POLARITY_INVERSED) | |
162 | pstate.duty_cycle = pstate.period; | |
163 | else | |
164 | pstate.duty_cycle = 0; | |
165 | } | |
166 | ||
ea398e28 | 167 | voltage = pwm_get_relative_duty_cycle(&pstate, duty_unit); |
c92688ca MB |
168 | if (voltage < min(max_uV_duty, min_uV_duty) || |
169 | voltage > max(max_uV_duty, min_uV_duty)) | |
170 | return -ENOTRECOVERABLE; | |
ea398e28 BB |
171 | |
172 | /* | |
173 | * The dutycycle for min_uV might be greater than the one for max_uV. | |
174 | * This is happening when the user needs an inversed polarity, but the | |
175 | * PWM device does not support inversing it in hardware. | |
176 | */ | |
177 | if (max_uV_duty < min_uV_duty) { | |
178 | voltage = min_uV_duty - voltage; | |
179 | diff_duty = min_uV_duty - max_uV_duty; | |
180 | } else { | |
181 | voltage = voltage - min_uV_duty; | |
182 | diff_duty = max_uV_duty - min_uV_duty; | |
183 | } | |
184 | ||
185 | voltage = DIV_ROUND_CLOSEST_ULL((u64)voltage * diff_uV, diff_duty); | |
186 | ||
187 | return voltage + min_uV; | |
4773be18 LJ |
188 | } |
189 | ||
190 | static int pwm_regulator_set_voltage(struct regulator_dev *rdev, | |
ea398e28 BB |
191 | int req_min_uV, int req_max_uV, |
192 | unsigned int *selector) | |
4773be18 LJ |
193 | { |
194 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); | |
ea398e28 BB |
195 | unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle; |
196 | unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle; | |
197 | unsigned int duty_unit = drvdata->continuous.dutycycle_unit; | |
ea398e28 BB |
198 | int min_uV = rdev->constraints->min_uV; |
199 | int max_uV = rdev->constraints->max_uV; | |
200 | int diff_uV = max_uV - min_uV; | |
3f4eb39b | 201 | struct pwm_state pstate; |
ea398e28 BB |
202 | unsigned int diff_duty; |
203 | unsigned int dutycycle; | |
4773be18 LJ |
204 | int ret; |
205 | ||
3f4eb39b | 206 | pwm_init_state(drvdata->pwm, &pstate); |
fd786fb0 | 207 | |
ea398e28 BB |
208 | /* |
209 | * The dutycycle for min_uV might be greater than the one for max_uV. | |
210 | * This is happening when the user needs an inversed polarity, but the | |
211 | * PWM device does not support inversing it in hardware. | |
212 | */ | |
213 | if (max_uV_duty < min_uV_duty) | |
214 | diff_duty = min_uV_duty - max_uV_duty; | |
215 | else | |
216 | diff_duty = max_uV_duty - min_uV_duty; | |
217 | ||
218 | dutycycle = DIV_ROUND_CLOSEST_ULL((u64)(req_min_uV - min_uV) * | |
219 | diff_duty, | |
220 | diff_uV); | |
221 | ||
222 | if (max_uV_duty < min_uV_duty) | |
223 | dutycycle = min_uV_duty - dutycycle; | |
224 | else | |
225 | dutycycle = min_uV_duty + dutycycle; | |
226 | ||
227 | pwm_set_relative_duty_cycle(&pstate, dutycycle, duty_unit); | |
4773be18 | 228 | |
c748a6d7 | 229 | ret = pwm_apply_might_sleep(drvdata->pwm, &pstate); |
4773be18 | 230 | if (ret) { |
5bf59bd5 | 231 | dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); |
4773be18 LJ |
232 | return ret; |
233 | } | |
234 | ||
4773be18 LJ |
235 | return 0; |
236 | } | |
237 | ||
638aef7a | 238 | static const struct regulator_ops pwm_regulator_voltage_table_ops = { |
aa66cc66 CZ |
239 | .set_voltage_sel = pwm_regulator_set_voltage_sel, |
240 | .get_voltage_sel = pwm_regulator_get_voltage_sel, | |
241 | .list_voltage = pwm_regulator_list_voltage, | |
242 | .map_voltage = regulator_map_voltage_iterate, | |
1de7d802 BB |
243 | .enable = pwm_regulator_enable, |
244 | .disable = pwm_regulator_disable, | |
245 | .is_enabled = pwm_regulator_is_enabled, | |
aa66cc66 CZ |
246 | }; |
247 | ||
638aef7a | 248 | static const struct regulator_ops pwm_regulator_voltage_continuous_ops = { |
4773be18 LJ |
249 | .get_voltage = pwm_regulator_get_voltage, |
250 | .set_voltage = pwm_regulator_set_voltage, | |
1de7d802 BB |
251 | .enable = pwm_regulator_enable, |
252 | .disable = pwm_regulator_disable, | |
253 | .is_enabled = pwm_regulator_is_enabled, | |
4773be18 LJ |
254 | }; |
255 | ||
638aef7a | 256 | static const struct regulator_desc pwm_regulator_desc = { |
aa66cc66 | 257 | .name = "pwm-regulator", |
aa66cc66 CZ |
258 | .type = REGULATOR_VOLTAGE, |
259 | .owner = THIS_MODULE, | |
260 | .supply_name = "pwm", | |
261 | }; | |
262 | ||
f9178dad LJ |
263 | static int pwm_regulator_init_table(struct platform_device *pdev, |
264 | struct pwm_regulator_data *drvdata) | |
265 | { | |
266 | struct device_node *np = pdev->dev.of_node; | |
267 | struct pwm_voltages *duty_cycle_table; | |
60cb65eb | 268 | unsigned int length = 0; |
f9178dad LJ |
269 | int ret; |
270 | ||
271 | of_find_property(np, "voltage-table", &length); | |
272 | ||
273 | if ((length < sizeof(*duty_cycle_table)) || | |
60377339 UKK |
274 | (length % sizeof(*duty_cycle_table))) |
275 | return dev_err_probe(&pdev->dev, -EINVAL, | |
276 | "voltage-table length(%d) is invalid\n", | |
277 | length); | |
f9178dad LJ |
278 | |
279 | duty_cycle_table = devm_kzalloc(&pdev->dev, length, GFP_KERNEL); | |
280 | if (!duty_cycle_table) | |
281 | return -ENOMEM; | |
282 | ||
283 | ret = of_property_read_u32_array(np, "voltage-table", | |
284 | (u32 *)duty_cycle_table, | |
285 | length / sizeof(u32)); | |
60377339 UKK |
286 | if (ret) |
287 | return dev_err_probe(&pdev->dev, ret, | |
288 | "Failed to read voltage-table\n"); | |
f9178dad | 289 | |
59ae97a7 | 290 | drvdata->state = -ENOTRECOVERABLE; |
f9178dad | 291 | drvdata->duty_cycle_table = duty_cycle_table; |
638aef7a | 292 | drvdata->desc.ops = &pwm_regulator_voltage_table_ops; |
f907a0a9 | 293 | drvdata->desc.n_voltages = length / sizeof(*duty_cycle_table); |
f9178dad LJ |
294 | |
295 | return 0; | |
296 | } | |
297 | ||
4773be18 LJ |
298 | static int pwm_regulator_init_continuous(struct platform_device *pdev, |
299 | struct pwm_regulator_data *drvdata) | |
300 | { | |
ea398e28 BB |
301 | u32 dutycycle_range[2] = { 0, 100 }; |
302 | u32 dutycycle_unit = 100; | |
303 | ||
638aef7a | 304 | drvdata->desc.ops = &pwm_regulator_voltage_continuous_ops; |
f907a0a9 | 305 | drvdata->desc.continuous_voltage_range = true; |
4773be18 | 306 | |
ea398e28 BB |
307 | of_property_read_u32_array(pdev->dev.of_node, |
308 | "pwm-dutycycle-range", | |
309 | dutycycle_range, 2); | |
310 | of_property_read_u32(pdev->dev.of_node, "pwm-dutycycle-unit", | |
311 | &dutycycle_unit); | |
312 | ||
313 | if (dutycycle_range[0] > dutycycle_unit || | |
314 | dutycycle_range[1] > dutycycle_unit) | |
315 | return -EINVAL; | |
316 | ||
317 | drvdata->continuous.dutycycle_unit = dutycycle_unit; | |
318 | drvdata->continuous.min_uV_dutycycle = dutycycle_range[0]; | |
319 | drvdata->continuous.max_uV_dutycycle = dutycycle_range[1]; | |
320 | ||
4773be18 LJ |
321 | return 0; |
322 | } | |
323 | ||
b3cbdcc1 MB |
324 | static int pwm_regulator_init_boot_on(struct platform_device *pdev, |
325 | struct pwm_regulator_data *drvdata, | |
326 | const struct regulator_init_data *init_data) | |
327 | { | |
328 | struct pwm_state pstate; | |
329 | ||
330 | if (!init_data->constraints.boot_on || drvdata->enb_gpio) | |
331 | return 0; | |
332 | ||
333 | pwm_get_state(drvdata->pwm, &pstate); | |
334 | if (pstate.enabled) | |
335 | return 0; | |
336 | ||
337 | /* | |
338 | * Update the duty cycle so the output does not change | |
339 | * when the regulator core enables the regulator (and | |
340 | * thus the PWM channel). | |
341 | */ | |
342 | if (pstate.polarity == PWM_POLARITY_INVERSED) | |
343 | pstate.duty_cycle = pstate.period; | |
344 | else | |
345 | pstate.duty_cycle = 0; | |
346 | ||
347 | return pwm_apply_might_sleep(drvdata->pwm, &pstate); | |
348 | } | |
349 | ||
aa66cc66 CZ |
350 | static int pwm_regulator_probe(struct platform_device *pdev) |
351 | { | |
5ad2cb14 | 352 | const struct regulator_init_data *init_data; |
aa66cc66 | 353 | struct pwm_regulator_data *drvdata; |
aa66cc66 CZ |
354 | struct regulator_dev *regulator; |
355 | struct regulator_config config = { }; | |
356 | struct device_node *np = pdev->dev.of_node; | |
27bfa889 | 357 | enum gpiod_flags gpio_flags; |
f9178dad | 358 | int ret; |
aa66cc66 | 359 | |
60377339 UKK |
360 | if (!np) |
361 | return dev_err_probe(&pdev->dev, -EINVAL, | |
362 | "Device Tree node missing\n"); | |
aa66cc66 CZ |
363 | |
364 | drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL); | |
365 | if (!drvdata) | |
366 | return -ENOMEM; | |
367 | ||
f907a0a9 LD |
368 | memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc)); |
369 | ||
7dda20c9 | 370 | if (of_property_present(np, "voltage-table")) |
f9178dad | 371 | ret = pwm_regulator_init_table(pdev, drvdata); |
4773be18 LJ |
372 | else |
373 | ret = pwm_regulator_init_continuous(pdev, drvdata); | |
374 | if (ret) | |
375 | return ret; | |
aa66cc66 | 376 | |
5ad2cb14 | 377 | init_data = of_get_regulator_init_data(&pdev->dev, np, |
f907a0a9 | 378 | &drvdata->desc); |
5ad2cb14 | 379 | if (!init_data) |
aa66cc66 CZ |
380 | return -ENOMEM; |
381 | ||
382 | config.of_node = np; | |
383 | config.dev = &pdev->dev; | |
384 | config.driver_data = drvdata; | |
5ad2cb14 | 385 | config.init_data = init_data; |
aa66cc66 CZ |
386 | |
387 | drvdata->pwm = devm_pwm_get(&pdev->dev, NULL); | |
e458d3f3 AM |
388 | if (IS_ERR(drvdata->pwm)) |
389 | return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->pwm), | |
390 | "Failed to get PWM\n"); | |
aa66cc66 | 391 | |
27bfa889 AC |
392 | if (init_data->constraints.boot_on || init_data->constraints.always_on) |
393 | gpio_flags = GPIOD_OUT_HIGH; | |
394 | else | |
395 | gpio_flags = GPIOD_OUT_LOW; | |
396 | drvdata->enb_gpio = devm_gpiod_get_optional(&pdev->dev, "enable", | |
397 | gpio_flags); | |
398 | if (IS_ERR(drvdata->enb_gpio)) { | |
399 | ret = PTR_ERR(drvdata->enb_gpio); | |
60377339 | 400 | return dev_err_probe(&pdev->dev, ret, "Failed to get enable GPIO\n"); |
27bfa889 AC |
401 | } |
402 | ||
fd4f99c4 BB |
403 | ret = pwm_adjust_config(drvdata->pwm); |
404 | if (ret) | |
405 | return ret; | |
8c12ad8e | 406 | |
b3cbdcc1 | 407 | ret = pwm_regulator_init_boot_on(pdev, drvdata, init_data); |
60377339 UKK |
408 | if (ret) |
409 | return dev_err_probe(&pdev->dev, ret, | |
410 | "Failed to apply boot_on settings\n"); | |
b3cbdcc1 | 411 | |
aa66cc66 | 412 | regulator = devm_regulator_register(&pdev->dev, |
f907a0a9 | 413 | &drvdata->desc, &config); |
aa66cc66 | 414 | if (IS_ERR(regulator)) { |
5bf59bd5 | 415 | ret = PTR_ERR(regulator); |
60377339 UKK |
416 | return dev_err_probe(&pdev->dev, ret, |
417 | "Failed to register regulator %s\n", | |
418 | drvdata->desc.name); | |
aa66cc66 CZ |
419 | } |
420 | ||
421 | return 0; | |
422 | } | |
423 | ||
dc8c5ea3 | 424 | static const struct of_device_id __maybe_unused pwm_of_match[] = { |
aa66cc66 CZ |
425 | { .compatible = "pwm-regulator" }, |
426 | { }, | |
427 | }; | |
428 | MODULE_DEVICE_TABLE(of, pwm_of_match); | |
429 | ||
430 | static struct platform_driver pwm_regulator_driver = { | |
431 | .driver = { | |
432 | .name = "pwm-regulator", | |
259b93b2 | 433 | .probe_type = PROBE_PREFER_ASYNCHRONOUS, |
aa66cc66 CZ |
434 | .of_match_table = of_match_ptr(pwm_of_match), |
435 | }, | |
436 | .probe = pwm_regulator_probe, | |
437 | }; | |
438 | ||
439 | module_platform_driver(pwm_regulator_driver); | |
440 | ||
441 | MODULE_LICENSE("GPL"); | |
442 | MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>"); | |
443 | MODULE_DESCRIPTION("PWM Regulator Driver"); | |
444 | MODULE_ALIAS("platform:pwm-regulator"); |