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25#include <linux/err.h>
26#include <linux/mutex.h>
27#include <linux/module.h>
28#include <linux/platform_device.h>
29#include <linux/regulator/driver.h>
30#include <linux/regulator/machine.h>
31#include <linux/regulator/of_regulator.h>
32#include <linux/regulator/gpio-regulator.h>
33#include <linux/gpio.h>
34#include <linux/slab.h>
35#include <linux/of.h>
36#include <linux/of_gpio.h>
37
38struct gpio_regulator_data {
39 struct regulator_desc desc;
40 struct regulator_dev *dev;
41
42 struct gpio *gpios;
43 int nr_gpios;
44
45 struct gpio_regulator_state *states;
46 int nr_states;
47
48 int state;
49};
50
51static int gpio_regulator_get_value(struct regulator_dev *dev)
52{
53 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
54 int ptr;
55
56 for (ptr = 0; ptr < data->nr_states; ptr++)
57 if (data->states[ptr].gpios == data->state)
58 return data->states[ptr].value;
59
60 return -EINVAL;
61}
62
63static int gpio_regulator_set_voltage(struct regulator_dev *dev,
64 int min_uV, int max_uV,
65 unsigned *selector)
66{
67 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
68 int ptr, target = 0, state, best_val = INT_MAX;
69
70 for (ptr = 0; ptr < data->nr_states; ptr++)
71 if (data->states[ptr].value < best_val &&
72 data->states[ptr].value >= min_uV &&
73 data->states[ptr].value <= max_uV) {
74 target = data->states[ptr].gpios;
75 best_val = data->states[ptr].value;
76 if (selector)
77 *selector = ptr;
78 }
79
80 if (best_val == INT_MAX)
81 return -EINVAL;
82
83 for (ptr = 0; ptr < data->nr_gpios; ptr++) {
84 state = (target & (1 << ptr)) >> ptr;
85 gpio_set_value_cansleep(data->gpios[ptr].gpio, state);
86 }
87 data->state = target;
88
89 return 0;
90}
91
92static int gpio_regulator_list_voltage(struct regulator_dev *dev,
93 unsigned selector)
94{
95 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
96
97 if (selector >= data->nr_states)
98 return -EINVAL;
99
100 return data->states[selector].value;
101}
102
103static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
104 int min_uA, int max_uA)
105{
106 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
107 int ptr, target = 0, state, best_val = 0;
108
109 for (ptr = 0; ptr < data->nr_states; ptr++)
110 if (data->states[ptr].value > best_val &&
111 data->states[ptr].value >= min_uA &&
112 data->states[ptr].value <= max_uA) {
113 target = data->states[ptr].gpios;
114 best_val = data->states[ptr].value;
115 }
116
117 if (best_val == 0)
118 return -EINVAL;
119
120 for (ptr = 0; ptr < data->nr_gpios; ptr++) {
121 state = (target & (1 << ptr)) >> ptr;
122 gpio_set_value_cansleep(data->gpios[ptr].gpio, state);
123 }
124 data->state = target;
125
126 return 0;
127}
128
129static struct regulator_ops gpio_regulator_voltage_ops = {
130 .get_voltage = gpio_regulator_get_value,
131 .set_voltage = gpio_regulator_set_voltage,
132 .list_voltage = gpio_regulator_list_voltage,
133};
134
135static struct gpio_regulator_config *
136of_get_gpio_regulator_config(struct device *dev, struct device_node *np,
137 const struct regulator_desc *desc)
138{
139 struct gpio_regulator_config *config;
140 const char *regtype;
141 int proplen, gpio, i;
142 int ret;
143
144 config = devm_kzalloc(dev,
145 sizeof(struct gpio_regulator_config),
146 GFP_KERNEL);
147 if (!config)
148 return ERR_PTR(-ENOMEM);
149
150 config->init_data = of_get_regulator_init_data(dev, np, desc);
151 if (!config->init_data)
152 return ERR_PTR(-EINVAL);
153
154 config->supply_name = config->init_data->constraints.name;
155
156 if (of_property_read_bool(np, "enable-active-high"))
157 config->enable_high = true;
158
159 if (of_property_read_bool(np, "enable-at-boot"))
160 config->enabled_at_boot = true;
161
162 of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
163
164 config->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
165
166
167 ret = of_gpio_count(np);
168 if ((ret < 0) && (ret != -ENOENT))
169 return ERR_PTR(ret);
170
171 if (ret > 0) {
172 config->nr_gpios = ret;
173 config->gpios = devm_kzalloc(dev,
174 sizeof(struct gpio) * config->nr_gpios,
175 GFP_KERNEL);
176 if (!config->gpios)
177 return ERR_PTR(-ENOMEM);
178
179 proplen = of_property_count_u32_elems(np, "gpios-states");
180
181 if (proplen < 0)
182 proplen = 0;
183
184 if (proplen > 0 && proplen != config->nr_gpios) {
185 dev_warn(dev, "gpios <-> gpios-states mismatch\n");
186 proplen = 0;
187 }
188
189 for (i = 0; i < config->nr_gpios; i++) {
190 gpio = of_get_named_gpio(np, "gpios", i);
191 if (gpio < 0)
192 break;
193 config->gpios[i].gpio = gpio;
194 if (proplen > 0) {
195 of_property_read_u32_index(np, "gpios-states",
196 i, &ret);
197 if (ret)
198 config->gpios[i].flags =
199 GPIOF_OUT_INIT_HIGH;
200 }
201 }
202 }
203
204
205 proplen = of_property_count_u32_elems(np, "states");
206 if (proplen < 0) {
207 dev_err(dev, "No 'states' property found\n");
208 return ERR_PTR(-EINVAL);
209 }
210
211 config->states = devm_kzalloc(dev,
212 sizeof(struct gpio_regulator_state)
213 * (proplen / 2),
214 GFP_KERNEL);
215 if (!config->states)
216 return ERR_PTR(-ENOMEM);
217
218 for (i = 0; i < proplen / 2; i++) {
219 of_property_read_u32_index(np, "states", i * 2,
220 &config->states[i].value);
221 of_property_read_u32_index(np, "states", i * 2 + 1,
222 &config->states[i].gpios);
223 }
224 config->nr_states = i;
225
226 config->type = REGULATOR_VOLTAGE;
227 ret = of_property_read_string(np, "regulator-type", ®type);
228 if (ret >= 0) {
229 if (!strncmp("voltage", regtype, 7))
230 config->type = REGULATOR_VOLTAGE;
231 else if (!strncmp("current", regtype, 7))
232 config->type = REGULATOR_CURRENT;
233 else
234 dev_warn(dev, "Unknown regulator-type '%s'\n",
235 regtype);
236 }
237
238 return config;
239}
240
241static struct regulator_ops gpio_regulator_current_ops = {
242 .get_current_limit = gpio_regulator_get_value,
243 .set_current_limit = gpio_regulator_set_current_limit,
244};
245
246static int gpio_regulator_probe(struct platform_device *pdev)
247{
248 struct gpio_regulator_config *config = dev_get_platdata(&pdev->dev);
249 struct device_node *np = pdev->dev.of_node;
250 struct gpio_regulator_data *drvdata;
251 struct regulator_config cfg = { };
252 int ptr, ret, state;
253
254 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
255 GFP_KERNEL);
256 if (drvdata == NULL)
257 return -ENOMEM;
258
259 if (np) {
260 config = of_get_gpio_regulator_config(&pdev->dev, np,
261 &drvdata->desc);
262 if (IS_ERR(config))
263 return PTR_ERR(config);
264 }
265
266 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
267 if (drvdata->desc.name == NULL) {
268 dev_err(&pdev->dev, "Failed to allocate supply name\n");
269 ret = -ENOMEM;
270 goto err;
271 }
272
273 if (config->nr_gpios != 0) {
274 drvdata->gpios = kmemdup(config->gpios,
275 config->nr_gpios * sizeof(struct gpio),
276 GFP_KERNEL);
277 if (drvdata->gpios == NULL) {
278 dev_err(&pdev->dev, "Failed to allocate gpio data\n");
279 ret = -ENOMEM;
280 goto err_name;
281 }
282
283 drvdata->nr_gpios = config->nr_gpios;
284 ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
285 if (ret) {
286 dev_err(&pdev->dev,
287 "Could not obtain regulator setting GPIOs: %d\n", ret);
288 goto err_memstate;
289 }
290 }
291
292 drvdata->states = kmemdup(config->states,
293 config->nr_states *
294 sizeof(struct gpio_regulator_state),
295 GFP_KERNEL);
296 if (drvdata->states == NULL) {
297 dev_err(&pdev->dev, "Failed to allocate state data\n");
298 ret = -ENOMEM;
299 goto err_memgpio;
300 }
301 drvdata->nr_states = config->nr_states;
302
303 drvdata->desc.owner = THIS_MODULE;
304 drvdata->desc.enable_time = config->startup_delay;
305
306
307 switch (config->type) {
308 case REGULATOR_VOLTAGE:
309 drvdata->desc.type = REGULATOR_VOLTAGE;
310 drvdata->desc.ops = &gpio_regulator_voltage_ops;
311 drvdata->desc.n_voltages = config->nr_states;
312 break;
313 case REGULATOR_CURRENT:
314 drvdata->desc.type = REGULATOR_CURRENT;
315 drvdata->desc.ops = &gpio_regulator_current_ops;
316 break;
317 default:
318 dev_err(&pdev->dev, "No regulator type set\n");
319 ret = -EINVAL;
320 goto err_memgpio;
321 }
322
323
324 state = 0;
325 for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
326 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
327 state |= (1 << ptr);
328 }
329 drvdata->state = state;
330
331 cfg.dev = &pdev->dev;
332 cfg.init_data = config->init_data;
333 cfg.driver_data = drvdata;
334 cfg.of_node = np;
335
336 if (gpio_is_valid(config->enable_gpio)) {
337 cfg.ena_gpio = config->enable_gpio;
338 cfg.ena_gpio_initialized = true;
339 }
340 cfg.ena_gpio_invert = !config->enable_high;
341 if (config->enabled_at_boot) {
342 if (config->enable_high)
343 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
344 else
345 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
346 } else {
347 if (config->enable_high)
348 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
349 else
350 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
351 }
352
353 drvdata->dev = regulator_register(&drvdata->desc, &cfg);
354 if (IS_ERR(drvdata->dev)) {
355 ret = PTR_ERR(drvdata->dev);
356 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
357 goto err_stategpio;
358 }
359
360 platform_set_drvdata(pdev, drvdata);
361
362 return 0;
363
364err_stategpio:
365 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
366err_memstate:
367 kfree(drvdata->states);
368err_memgpio:
369 kfree(drvdata->gpios);
370err_name:
371 kfree(drvdata->desc.name);
372err:
373 return ret;
374}
375
376static int gpio_regulator_remove(struct platform_device *pdev)
377{
378 struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
379
380 regulator_unregister(drvdata->dev);
381
382 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
383
384 kfree(drvdata->states);
385 kfree(drvdata->gpios);
386
387 kfree(drvdata->desc.name);
388
389 return 0;
390}
391
392#if defined(CONFIG_OF)
393static const struct of_device_id regulator_gpio_of_match[] = {
394 { .compatible = "regulator-gpio", },
395 {},
396};
397MODULE_DEVICE_TABLE(of, regulator_gpio_of_match);
398#endif
399
400static struct platform_driver gpio_regulator_driver = {
401 .probe = gpio_regulator_probe,
402 .remove = gpio_regulator_remove,
403 .driver = {
404 .name = "gpio-regulator",
405 .of_match_table = of_match_ptr(regulator_gpio_of_match),
406 },
407};
408
409static int __init gpio_regulator_init(void)
410{
411 return platform_driver_register(&gpio_regulator_driver);
412}
413subsys_initcall(gpio_regulator_init);
414
415static void __exit gpio_regulator_exit(void)
416{
417 platform_driver_unregister(&gpio_regulator_driver);
418}
419module_exit(gpio_regulator_exit);
420
421MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
422MODULE_DESCRIPTION("gpio voltage regulator");
423MODULE_LICENSE("GPL");
424MODULE_ALIAS("platform:gpio-regulator");
425
