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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{
138 struct gpio_regulator_config *config;
139 struct property *prop;
140 const char *regtype;
141 int proplen, gpio, i;
142
143 config = devm_kzalloc(dev,
144 sizeof(struct gpio_regulator_config),
145 GFP_KERNEL);
146 if (!config)
147 return ERR_PTR(-ENOMEM);
148
149 config->init_data = of_get_regulator_init_data(dev, np);
150 if (!config->init_data)
151 return ERR_PTR(-EINVAL);
152
153 config->supply_name = config->init_data->constraints.name;
154
155 if (of_property_read_bool(np, "enable-active-high"))
156 config->enable_high = true;
157
158 if (of_property_read_bool(np, "enable-at-boot"))
159 config->enabled_at_boot = true;
160
161 of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
162
163 config->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
164
165
166 config->nr_gpios = of_gpio_count(np);
167
168 config->gpios = devm_kzalloc(dev,
169 sizeof(struct gpio) * config->nr_gpios,
170 GFP_KERNEL);
171 if (!config->gpios)
172 return ERR_PTR(-ENOMEM);
173
174 for (i = 0; i < config->nr_gpios; i++) {
175 gpio = of_get_named_gpio(np, "gpios", i);
176 if (gpio < 0)
177 break;
178 config->gpios[i].gpio = gpio;
179 }
180
181
182 prop = of_find_property(np, "states", NULL);
183 if (!prop) {
184 dev_err(dev, "No 'states' property found\n");
185 return ERR_PTR(-EINVAL);
186 }
187
188 proplen = prop->length / sizeof(int);
189
190 config->states = devm_kzalloc(dev,
191 sizeof(struct gpio_regulator_state)
192 * (proplen / 2),
193 GFP_KERNEL);
194 if (!config->states)
195 return ERR_PTR(-ENOMEM);
196
197 for (i = 0; i < proplen / 2; i++) {
198 config->states[i].value =
199 be32_to_cpup((int *)prop->value + (i * 2));
200 config->states[i].gpios =
201 be32_to_cpup((int *)prop->value + (i * 2 + 1));
202 }
203 config->nr_states = i;
204
205 of_property_read_string(np, "regulator-type", ®type);
206
207 if (!strncmp("voltage", regtype, 7))
208 config->type = REGULATOR_VOLTAGE;
209 else if (!strncmp("current", regtype, 7))
210 config->type = REGULATOR_CURRENT;
211
212 return config;
213}
214
215static struct regulator_ops gpio_regulator_current_ops = {
216 .get_current_limit = gpio_regulator_get_value,
217 .set_current_limit = gpio_regulator_set_current_limit,
218};
219
220static int gpio_regulator_probe(struct platform_device *pdev)
221{
222 struct gpio_regulator_config *config = pdev->dev.platform_data;
223 struct device_node *np = pdev->dev.of_node;
224 struct gpio_regulator_data *drvdata;
225 struct regulator_config cfg = { };
226 int ptr, ret, state;
227
228 if (np) {
229 config = of_get_gpio_regulator_config(&pdev->dev, np);
230 if (IS_ERR(config))
231 return PTR_ERR(config);
232 }
233
234 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
235 GFP_KERNEL);
236 if (drvdata == NULL) {
237 dev_err(&pdev->dev, "Failed to allocate device data\n");
238 return -ENOMEM;
239 }
240
241 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
242 if (drvdata->desc.name == NULL) {
243 dev_err(&pdev->dev, "Failed to allocate supply name\n");
244 ret = -ENOMEM;
245 goto err;
246 }
247
248 drvdata->gpios = kmemdup(config->gpios,
249 config->nr_gpios * sizeof(struct gpio),
250 GFP_KERNEL);
251 if (drvdata->gpios == NULL) {
252 dev_err(&pdev->dev, "Failed to allocate gpio data\n");
253 ret = -ENOMEM;
254 goto err_name;
255 }
256
257 drvdata->states = kmemdup(config->states,
258 config->nr_states *
259 sizeof(struct gpio_regulator_state),
260 GFP_KERNEL);
261 if (drvdata->states == NULL) {
262 dev_err(&pdev->dev, "Failed to allocate state data\n");
263 ret = -ENOMEM;
264 goto err_memgpio;
265 }
266 drvdata->nr_states = config->nr_states;
267
268 drvdata->desc.owner = THIS_MODULE;
269 drvdata->desc.enable_time = config->startup_delay;
270
271
272 switch (config->type) {
273 case REGULATOR_VOLTAGE:
274 drvdata->desc.type = REGULATOR_VOLTAGE;
275 drvdata->desc.ops = &gpio_regulator_voltage_ops;
276 drvdata->desc.n_voltages = config->nr_states;
277 break;
278 case REGULATOR_CURRENT:
279 drvdata->desc.type = REGULATOR_CURRENT;
280 drvdata->desc.ops = &gpio_regulator_current_ops;
281 break;
282 default:
283 dev_err(&pdev->dev, "No regulator type set\n");
284 ret = -EINVAL;
285 goto err_memgpio;
286 break;
287 }
288
289 drvdata->nr_gpios = config->nr_gpios;
290 ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
291 if (ret) {
292 dev_err(&pdev->dev,
293 "Could not obtain regulator setting GPIOs: %d\n", ret);
294 goto err_memstate;
295 }
296
297
298 state = 0;
299 for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
300 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
301 state |= (1 << ptr);
302 }
303 drvdata->state = state;
304
305 cfg.dev = &pdev->dev;
306 cfg.init_data = config->init_data;
307 cfg.driver_data = drvdata;
308 cfg.of_node = np;
309
310 if (config->enable_gpio >= 0)
311 cfg.ena_gpio = config->enable_gpio;
312 cfg.ena_gpio_invert = !config->enable_high;
313 if (config->enabled_at_boot) {
314 if (config->enable_high)
315 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
316 else
317 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
318 } else {
319 if (config->enable_high)
320 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
321 else
322 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
323 }
324
325 drvdata->dev = regulator_register(&drvdata->desc, &cfg);
326 if (IS_ERR(drvdata->dev)) {
327 ret = PTR_ERR(drvdata->dev);
328 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
329 goto err_stategpio;
330 }
331
332 platform_set_drvdata(pdev, drvdata);
333
334 return 0;
335
336err_stategpio:
337 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
338err_memstate:
339 kfree(drvdata->states);
340err_memgpio:
341 kfree(drvdata->gpios);
342err_name:
343 kfree(drvdata->desc.name);
344err:
345 return ret;
346}
347
348static int gpio_regulator_remove(struct platform_device *pdev)
349{
350 struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
351
352 regulator_unregister(drvdata->dev);
353
354 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
355
356 kfree(drvdata->states);
357 kfree(drvdata->gpios);
358
359 kfree(drvdata->desc.name);
360
361 return 0;
362}
363
364#if defined(CONFIG_OF)
365static const struct of_device_id regulator_gpio_of_match[] = {
366 { .compatible = "regulator-gpio", },
367 {},
368};
369#endif
370
371static struct platform_driver gpio_regulator_driver = {
372 .probe = gpio_regulator_probe,
373 .remove = gpio_regulator_remove,
374 .driver = {
375 .name = "gpio-regulator",
376 .owner = THIS_MODULE,
377 .of_match_table = of_match_ptr(regulator_gpio_of_match),
378 },
379};
380
381static int __init gpio_regulator_init(void)
382{
383 return platform_driver_register(&gpio_regulator_driver);
384}
385subsys_initcall(gpio_regulator_init);
386
387static void __exit gpio_regulator_exit(void)
388{
389 platform_driver_unregister(&gpio_regulator_driver);
390}
391module_exit(gpio_regulator_exit);
392
393MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
394MODULE_DESCRIPTION("gpio voltage regulator");
395MODULE_LICENSE("GPL");
396MODULE_ALIAS("platform:gpio-regulator");
397
