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