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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 if (config->enable_gpio < 0 && config->enable_gpio != -ENOENT)
166 return ERR_PTR(config->enable_gpio);
167
168
169 ret = of_gpio_count(np);
170 if ((ret < 0) && (ret != -ENOENT))
171 return ERR_PTR(ret);
172
173 if (ret > 0) {
174 config->nr_gpios = ret;
175 config->gpios = devm_kzalloc(dev,
176 sizeof(struct gpio) * config->nr_gpios,
177 GFP_KERNEL);
178 if (!config->gpios)
179 return ERR_PTR(-ENOMEM);
180
181 proplen = of_property_count_u32_elems(np, "gpios-states");
182
183 if (proplen < 0)
184 proplen = 0;
185
186 if (proplen > 0 && proplen != config->nr_gpios) {
187 dev_warn(dev, "gpios <-> gpios-states mismatch\n");
188 proplen = 0;
189 }
190
191 for (i = 0; i < config->nr_gpios; i++) {
192 gpio = of_get_named_gpio(np, "gpios", i);
193 if (gpio < 0) {
194 if (gpio != -ENOENT)
195 return ERR_PTR(gpio);
196 break;
197 }
198 config->gpios[i].gpio = gpio;
199 if (proplen > 0) {
200 of_property_read_u32_index(np, "gpios-states",
201 i, &ret);
202 if (ret)
203 config->gpios[i].flags =
204 GPIOF_OUT_INIT_HIGH;
205 }
206 }
207 }
208
209
210 proplen = of_property_count_u32_elems(np, "states");
211 if (proplen < 0) {
212 dev_err(dev, "No 'states' property found\n");
213 return ERR_PTR(-EINVAL);
214 }
215
216 config->states = devm_kzalloc(dev,
217 sizeof(struct gpio_regulator_state)
218 * (proplen / 2),
219 GFP_KERNEL);
220 if (!config->states)
221 return ERR_PTR(-ENOMEM);
222
223 for (i = 0; i < proplen / 2; i++) {
224 of_property_read_u32_index(np, "states", i * 2,
225 &config->states[i].value);
226 of_property_read_u32_index(np, "states", i * 2 + 1,
227 &config->states[i].gpios);
228 }
229 config->nr_states = i;
230
231 config->type = REGULATOR_VOLTAGE;
232 ret = of_property_read_string(np, "regulator-type", ®type);
233 if (ret >= 0) {
234 if (!strncmp("voltage", regtype, 7))
235 config->type = REGULATOR_VOLTAGE;
236 else if (!strncmp("current", regtype, 7))
237 config->type = REGULATOR_CURRENT;
238 else
239 dev_warn(dev, "Unknown regulator-type '%s'\n",
240 regtype);
241 }
242
243 return config;
244}
245
246static struct regulator_ops gpio_regulator_current_ops = {
247 .get_current_limit = gpio_regulator_get_value,
248 .set_current_limit = gpio_regulator_set_current_limit,
249};
250
251static int gpio_regulator_probe(struct platform_device *pdev)
252{
253 struct gpio_regulator_config *config = dev_get_platdata(&pdev->dev);
254 struct device_node *np = pdev->dev.of_node;
255 struct gpio_regulator_data *drvdata;
256 struct regulator_config cfg = { };
257 int ptr, ret, state;
258
259 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
260 GFP_KERNEL);
261 if (drvdata == NULL)
262 return -ENOMEM;
263
264 if (np) {
265 config = of_get_gpio_regulator_config(&pdev->dev, np,
266 &drvdata->desc);
267 if (IS_ERR(config))
268 return PTR_ERR(config);
269 }
270
271 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
272 if (drvdata->desc.name == NULL) {
273 dev_err(&pdev->dev, "Failed to allocate supply name\n");
274 ret = -ENOMEM;
275 goto err;
276 }
277
278 if (config->nr_gpios != 0) {
279 drvdata->gpios = kmemdup(config->gpios,
280 config->nr_gpios * sizeof(struct gpio),
281 GFP_KERNEL);
282 if (drvdata->gpios == NULL) {
283 dev_err(&pdev->dev, "Failed to allocate gpio data\n");
284 ret = -ENOMEM;
285 goto err_name;
286 }
287
288 drvdata->nr_gpios = config->nr_gpios;
289 ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
290 if (ret) {
291 if (ret != -EPROBE_DEFER)
292 dev_err(&pdev->dev,
293 "Could not obtain regulator setting GPIOs: %d\n",
294 ret);
295 goto err_memstate;
296 }
297 }
298
299 drvdata->states = kmemdup(config->states,
300 config->nr_states *
301 sizeof(struct gpio_regulator_state),
302 GFP_KERNEL);
303 if (drvdata->states == NULL) {
304 dev_err(&pdev->dev, "Failed to allocate state data\n");
305 ret = -ENOMEM;
306 goto err_memgpio;
307 }
308 drvdata->nr_states = config->nr_states;
309
310 drvdata->desc.owner = THIS_MODULE;
311 drvdata->desc.enable_time = config->startup_delay;
312
313
314 switch (config->type) {
315 case REGULATOR_VOLTAGE:
316 drvdata->desc.type = REGULATOR_VOLTAGE;
317 drvdata->desc.ops = &gpio_regulator_voltage_ops;
318 drvdata->desc.n_voltages = config->nr_states;
319 break;
320 case REGULATOR_CURRENT:
321 drvdata->desc.type = REGULATOR_CURRENT;
322 drvdata->desc.ops = &gpio_regulator_current_ops;
323 break;
324 default:
325 dev_err(&pdev->dev, "No regulator type set\n");
326 ret = -EINVAL;
327 goto err_memgpio;
328 }
329
330
331 state = 0;
332 for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
333 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
334 state |= (1 << ptr);
335 }
336 drvdata->state = state;
337
338 cfg.dev = &pdev->dev;
339 cfg.init_data = config->init_data;
340 cfg.driver_data = drvdata;
341 cfg.of_node = np;
342
343 if (gpio_is_valid(config->enable_gpio)) {
344 cfg.ena_gpio = config->enable_gpio;
345 cfg.ena_gpio_initialized = true;
346 }
347 cfg.ena_gpio_invert = !config->enable_high;
348 if (config->enabled_at_boot) {
349 if (config->enable_high)
350 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
351 else
352 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
353 } else {
354 if (config->enable_high)
355 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
356 else
357 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
358 }
359
360 drvdata->dev = regulator_register(&drvdata->desc, &cfg);
361 if (IS_ERR(drvdata->dev)) {
362 ret = PTR_ERR(drvdata->dev);
363 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
364 goto err_stategpio;
365 }
366
367 platform_set_drvdata(pdev, drvdata);
368
369 return 0;
370
371err_stategpio:
372 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
373err_memstate:
374 kfree(drvdata->states);
375err_memgpio:
376 kfree(drvdata->gpios);
377err_name:
378 kfree(drvdata->desc.name);
379err:
380 return ret;
381}
382
383static int gpio_regulator_remove(struct platform_device *pdev)
384{
385 struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
386
387 regulator_unregister(drvdata->dev);
388
389 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
390
391 kfree(drvdata->states);
392 kfree(drvdata->gpios);
393
394 kfree(drvdata->desc.name);
395
396 return 0;
397}
398
399#if defined(CONFIG_OF)
400static const struct of_device_id regulator_gpio_of_match[] = {
401 { .compatible = "regulator-gpio", },
402 {},
403};
404MODULE_DEVICE_TABLE(of, regulator_gpio_of_match);
405#endif
406
407static struct platform_driver gpio_regulator_driver = {
408 .probe = gpio_regulator_probe,
409 .remove = gpio_regulator_remove,
410 .driver = {
411 .name = "gpio-regulator",
412 .of_match_table = of_match_ptr(regulator_gpio_of_match),
413 },
414};
415
416static int __init gpio_regulator_init(void)
417{
418 return platform_driver_register(&gpio_regulator_driver);
419}
420subsys_initcall(gpio_regulator_init);
421
422static void __exit gpio_regulator_exit(void)
423{
424 platform_driver_unregister(&gpio_regulator_driver);
425}
426module_exit(gpio_regulator_exit);
427
428MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
429MODULE_DESCRIPTION("gpio voltage regulator");
430MODULE_LICENSE("GPL");
431MODULE_ALIAS("platform:gpio-regulator");
432
