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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
24struct pwm_continuous_reg_data {
25 unsigned int min_uV_dutycycle;
26 unsigned int max_uV_dutycycle;
27 unsigned int dutycycle_unit;
28};
29
30struct pwm_regulator_data {
31
32 struct pwm_device *pwm;
33
34
35 struct pwm_voltages *duty_cycle_table;
36
37
38 struct pwm_continuous_reg_data continuous;
39
40
41 struct regulator_desc desc;
42
43
44 struct regulator_ops ops;
45
46 int state;
47
48
49 struct gpio_desc *enb_gpio;
50};
51
52struct pwm_voltages {
53 unsigned int uV;
54 unsigned int dutycycle;
55};
56
57
58
59
60static 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
78static 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
88static 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
110static 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
121static int pwm_regulator_enable(struct regulator_dev *dev)
122{
123 struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
124
125 gpiod_set_value_cansleep(drvdata->enb_gpio, 1);
126
127 return pwm_enable(drvdata->pwm);
128}
129
130static int pwm_regulator_disable(struct regulator_dev *dev)
131{
132 struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
133
134 pwm_disable(drvdata->pwm);
135
136 gpiod_set_value_cansleep(drvdata->enb_gpio, 0);
137
138 return 0;
139}
140
141static int pwm_regulator_is_enabled(struct regulator_dev *dev)
142{
143 struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
144
145 if (drvdata->enb_gpio && !gpiod_get_value_cansleep(drvdata->enb_gpio))
146 return false;
147
148 return pwm_is_enabled(drvdata->pwm);
149}
150
151static int pwm_regulator_get_voltage(struct regulator_dev *rdev)
152{
153 struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
154 unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle;
155 unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle;
156 unsigned int duty_unit = drvdata->continuous.dutycycle_unit;
157 int min_uV = rdev->constraints->min_uV;
158 int max_uV = rdev->constraints->max_uV;
159 int diff_uV = max_uV - min_uV;
160 struct pwm_state pstate;
161 unsigned int diff_duty;
162 unsigned int voltage;
163
164 pwm_get_state(drvdata->pwm, &pstate);
165
166 voltage = pwm_get_relative_duty_cycle(&pstate, duty_unit);
167
168
169
170
171
172
173 if (max_uV_duty < min_uV_duty) {
174 voltage = min_uV_duty - voltage;
175 diff_duty = min_uV_duty - max_uV_duty;
176 } else {
177 voltage = voltage - min_uV_duty;
178 diff_duty = max_uV_duty - min_uV_duty;
179 }
180
181 voltage = DIV_ROUND_CLOSEST_ULL((u64)voltage * diff_uV, diff_duty);
182
183 return voltage + min_uV;
184}
185
186static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
187 int req_min_uV, int req_max_uV,
188 unsigned int *selector)
189{
190 struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
191 unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle;
192 unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle;
193 unsigned int duty_unit = drvdata->continuous.dutycycle_unit;
194 int min_uV = rdev->constraints->min_uV;
195 int max_uV = rdev->constraints->max_uV;
196 int diff_uV = max_uV - min_uV;
197 struct pwm_state pstate;
198 unsigned int diff_duty;
199 unsigned int dutycycle;
200 int ret;
201
202 pwm_init_state(drvdata->pwm, &pstate);
203
204
205
206
207
208
209 if (max_uV_duty < min_uV_duty)
210 diff_duty = min_uV_duty - max_uV_duty;
211 else
212 diff_duty = max_uV_duty - min_uV_duty;
213
214 dutycycle = DIV_ROUND_CLOSEST_ULL((u64)(req_min_uV - min_uV) *
215 diff_duty,
216 diff_uV);
217
218 if (max_uV_duty < min_uV_duty)
219 dutycycle = min_uV_duty - dutycycle;
220 else
221 dutycycle = min_uV_duty + dutycycle;
222
223 pwm_set_relative_duty_cycle(&pstate, dutycycle, duty_unit);
224
225 ret = pwm_apply_state(drvdata->pwm, &pstate);
226 if (ret) {
227 dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret);
228 return ret;
229 }
230
231 return 0;
232}
233
234static struct regulator_ops pwm_regulator_voltage_table_ops = {
235 .set_voltage_sel = pwm_regulator_set_voltage_sel,
236 .get_voltage_sel = pwm_regulator_get_voltage_sel,
237 .list_voltage = pwm_regulator_list_voltage,
238 .map_voltage = regulator_map_voltage_iterate,
239 .enable = pwm_regulator_enable,
240 .disable = pwm_regulator_disable,
241 .is_enabled = pwm_regulator_is_enabled,
242};
243
244static struct regulator_ops pwm_regulator_voltage_continuous_ops = {
245 .get_voltage = pwm_regulator_get_voltage,
246 .set_voltage = pwm_regulator_set_voltage,
247 .enable = pwm_regulator_enable,
248 .disable = pwm_regulator_disable,
249 .is_enabled = pwm_regulator_is_enabled,
250};
251
252static struct regulator_desc pwm_regulator_desc = {
253 .name = "pwm-regulator",
254 .type = REGULATOR_VOLTAGE,
255 .owner = THIS_MODULE,
256 .supply_name = "pwm",
257};
258
259static int pwm_regulator_init_table(struct platform_device *pdev,
260 struct pwm_regulator_data *drvdata)
261{
262 struct device_node *np = pdev->dev.of_node;
263 struct pwm_voltages *duty_cycle_table;
264 unsigned int length = 0;
265 int ret;
266
267 of_find_property(np, "voltage-table", &length);
268
269 if ((length < sizeof(*duty_cycle_table)) ||
270 (length % sizeof(*duty_cycle_table))) {
271 dev_err(&pdev->dev, "voltage-table length(%d) is invalid\n",
272 length);
273 return -EINVAL;
274 }
275
276 duty_cycle_table = devm_kzalloc(&pdev->dev, length, GFP_KERNEL);
277 if (!duty_cycle_table)
278 return -ENOMEM;
279
280 ret = of_property_read_u32_array(np, "voltage-table",
281 (u32 *)duty_cycle_table,
282 length / sizeof(u32));
283 if (ret) {
284 dev_err(&pdev->dev, "Failed to read voltage-table: %d\n", ret);
285 return ret;
286 }
287
288 drvdata->state = -EINVAL;
289 drvdata->duty_cycle_table = duty_cycle_table;
290 memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops,
291 sizeof(drvdata->ops));
292 drvdata->desc.ops = &drvdata->ops;
293 drvdata->desc.n_voltages = length / sizeof(*duty_cycle_table);
294
295 return 0;
296}
297
298static int pwm_regulator_init_continuous(struct platform_device *pdev,
299 struct pwm_regulator_data *drvdata)
300{
301 u32 dutycycle_range[2] = { 0, 100 };
302 u32 dutycycle_unit = 100;
303
304 memcpy(&drvdata->ops, &pwm_regulator_voltage_continuous_ops,
305 sizeof(drvdata->ops));
306 drvdata->desc.ops = &drvdata->ops;
307 drvdata->desc.continuous_voltage_range = true;
308
309 of_property_read_u32_array(pdev->dev.of_node,
310 "pwm-dutycycle-range",
311 dutycycle_range, 2);
312 of_property_read_u32(pdev->dev.of_node, "pwm-dutycycle-unit",
313 &dutycycle_unit);
314
315 if (dutycycle_range[0] > dutycycle_unit ||
316 dutycycle_range[1] > dutycycle_unit)
317 return -EINVAL;
318
319 drvdata->continuous.dutycycle_unit = dutycycle_unit;
320 drvdata->continuous.min_uV_dutycycle = dutycycle_range[0];
321 drvdata->continuous.max_uV_dutycycle = dutycycle_range[1];
322
323 return 0;
324}
325
326static int pwm_regulator_probe(struct platform_device *pdev)
327{
328 const struct regulator_init_data *init_data;
329 struct pwm_regulator_data *drvdata;
330 struct regulator_dev *regulator;
331 struct regulator_config config = { };
332 struct device_node *np = pdev->dev.of_node;
333 enum gpiod_flags gpio_flags;
334 int ret;
335
336 if (!np) {
337 dev_err(&pdev->dev, "Device Tree node missing\n");
338 return -EINVAL;
339 }
340
341 drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
342 if (!drvdata)
343 return -ENOMEM;
344
345 memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc));
346
347 if (of_find_property(np, "voltage-table", NULL))
348 ret = pwm_regulator_init_table(pdev, drvdata);
349 else
350 ret = pwm_regulator_init_continuous(pdev, drvdata);
351 if (ret)
352 return ret;
353
354 init_data = of_get_regulator_init_data(&pdev->dev, np,
355 &drvdata->desc);
356 if (!init_data)
357 return -ENOMEM;
358
359 config.of_node = np;
360 config.dev = &pdev->dev;
361 config.driver_data = drvdata;
362 config.init_data = init_data;
363
364 drvdata->pwm = devm_pwm_get(&pdev->dev, NULL);
365 if (IS_ERR(drvdata->pwm)) {
366 ret = PTR_ERR(drvdata->pwm);
367 dev_err(&pdev->dev, "Failed to get PWM: %d\n", ret);
368 return ret;
369 }
370
371 if (init_data->constraints.boot_on || init_data->constraints.always_on)
372 gpio_flags = GPIOD_OUT_HIGH;
373 else
374 gpio_flags = GPIOD_OUT_LOW;
375 drvdata->enb_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
376 gpio_flags);
377 if (IS_ERR(drvdata->enb_gpio)) {
378 ret = PTR_ERR(drvdata->enb_gpio);
379 dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n", ret);
380 return ret;
381 }
382
383 ret = pwm_adjust_config(drvdata->pwm);
384 if (ret)
385 return ret;
386
387 regulator = devm_regulator_register(&pdev->dev,
388 &drvdata->desc, &config);
389 if (IS_ERR(regulator)) {
390 ret = PTR_ERR(regulator);
391 dev_err(&pdev->dev, "Failed to register regulator %s: %d\n",
392 drvdata->desc.name, ret);
393 return ret;
394 }
395
396 return 0;
397}
398
399static const struct of_device_id pwm_of_match[] = {
400 { .compatible = "pwm-regulator" },
401 { },
402};
403MODULE_DEVICE_TABLE(of, pwm_of_match);
404
405static struct platform_driver pwm_regulator_driver = {
406 .driver = {
407 .name = "pwm-regulator",
408 .of_match_table = of_match_ptr(pwm_of_match),
409 },
410 .probe = pwm_regulator_probe,
411};
412
413module_platform_driver(pwm_regulator_driver);
414
415MODULE_LICENSE("GPL");
416MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>");
417MODULE_DESCRIPTION("PWM Regulator Driver");
418MODULE_ALIAS("platform:pwm-regulator");
419
