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