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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 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);
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 config->nr_gpios = of_gpio_count(np);
168
169 config->gpios = devm_kzalloc(dev,
170 sizeof(struct gpio) * config->nr_gpios,
171 GFP_KERNEL);
172 if (!config->gpios)
173 return ERR_PTR(-ENOMEM);
174
175 for (i = 0; i < config->nr_gpios; i++) {
176 gpio = of_get_named_gpio(np, "gpios", i);
177 if (gpio < 0)
178 break;
179 config->gpios[i].gpio = gpio;
180 }
181
182
183 prop = of_find_property(np, "states", NULL);
184 if (!prop) {
185 dev_err(dev, "No 'states' property found\n");
186 return ERR_PTR(-EINVAL);
187 }
188
189 proplen = prop->length / sizeof(int);
190
191 config->states = devm_kzalloc(dev,
192 sizeof(struct gpio_regulator_state)
193 * (proplen / 2),
194 GFP_KERNEL);
195 if (!config->states)
196 return ERR_PTR(-ENOMEM);
197
198 for (i = 0; i < proplen / 2; i++) {
199 config->states[i].value =
200 be32_to_cpup((int *)prop->value + (i * 2));
201 config->states[i].gpios =
202 be32_to_cpup((int *)prop->value + (i * 2 + 1));
203 }
204 config->nr_states = i;
205
206 config->type = REGULATOR_VOLTAGE;
207 ret = of_property_read_string(np, "regulator-type", ®type);
208 if (ret >= 0) {
209 if (!strncmp("voltage", regtype, 7))
210 config->type = REGULATOR_VOLTAGE;
211 else if (!strncmp("current", regtype, 7))
212 config->type = REGULATOR_CURRENT;
213 else
214 dev_warn(dev, "Unknown regulator-type '%s'\n",
215 regtype);
216 }
217
218 return config;
219}
220
221static struct regulator_ops gpio_regulator_current_ops = {
222 .get_current_limit = gpio_regulator_get_value,
223 .set_current_limit = gpio_regulator_set_current_limit,
224};
225
226static int gpio_regulator_probe(struct platform_device *pdev)
227{
228 struct gpio_regulator_config *config = dev_get_platdata(&pdev->dev);
229 struct device_node *np = pdev->dev.of_node;
230 struct gpio_regulator_data *drvdata;
231 struct regulator_config cfg = { };
232 int ptr, ret, state;
233
234 if (np) {
235 config = of_get_gpio_regulator_config(&pdev->dev, np);
236 if (IS_ERR(config))
237 return PTR_ERR(config);
238 }
239
240 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
241 GFP_KERNEL);
242 if (drvdata == NULL) {
243 dev_err(&pdev->dev, "Failed to allocate device data\n");
244 return -ENOMEM;
245 }
246
247 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
248 if (drvdata->desc.name == NULL) {
249 dev_err(&pdev->dev, "Failed to allocate supply name\n");
250 ret = -ENOMEM;
251 goto err;
252 }
253
254 drvdata->gpios = kmemdup(config->gpios,
255 config->nr_gpios * sizeof(struct gpio),
256 GFP_KERNEL);
257 if (drvdata->gpios == NULL) {
258 dev_err(&pdev->dev, "Failed to allocate gpio data\n");
259 ret = -ENOMEM;
260 goto err_name;
261 }
262
263 drvdata->states = kmemdup(config->states,
264 config->nr_states *
265 sizeof(struct gpio_regulator_state),
266 GFP_KERNEL);
267 if (drvdata->states == NULL) {
268 dev_err(&pdev->dev, "Failed to allocate state data\n");
269 ret = -ENOMEM;
270 goto err_memgpio;
271 }
272 drvdata->nr_states = config->nr_states;
273
274 drvdata->desc.owner = THIS_MODULE;
275 drvdata->desc.enable_time = config->startup_delay;
276
277
278 switch (config->type) {
279 case REGULATOR_VOLTAGE:
280 drvdata->desc.type = REGULATOR_VOLTAGE;
281 drvdata->desc.ops = &gpio_regulator_voltage_ops;
282 drvdata->desc.n_voltages = config->nr_states;
283 break;
284 case REGULATOR_CURRENT:
285 drvdata->desc.type = REGULATOR_CURRENT;
286 drvdata->desc.ops = &gpio_regulator_current_ops;
287 break;
288 default:
289 dev_err(&pdev->dev, "No regulator type set\n");
290 ret = -EINVAL;
291 goto err_memgpio;
292 }
293
294 drvdata->nr_gpios = config->nr_gpios;
295 ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
296 if (ret) {
297 dev_err(&pdev->dev,
298 "Could not obtain regulator setting GPIOs: %d\n", ret);
299 goto err_memstate;
300 }
301
302
303 state = 0;
304 for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
305 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
306 state |= (1 << ptr);
307 }
308 drvdata->state = state;
309
310 cfg.dev = &pdev->dev;
311 cfg.init_data = config->init_data;
312 cfg.driver_data = drvdata;
313 cfg.of_node = np;
314
315 if (config->enable_gpio >= 0)
316 cfg.ena_gpio = config->enable_gpio;
317 cfg.ena_gpio_invert = !config->enable_high;
318 if (config->enabled_at_boot) {
319 if (config->enable_high)
320 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
321 else
322 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
323 } else {
324 if (config->enable_high)
325 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
326 else
327 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
328 }
329
330 drvdata->dev = regulator_register(&drvdata->desc, &cfg);
331 if (IS_ERR(drvdata->dev)) {
332 ret = PTR_ERR(drvdata->dev);
333 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
334 goto err_stategpio;
335 }
336
337 platform_set_drvdata(pdev, drvdata);
338
339 return 0;
340
341err_stategpio:
342 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
343err_memstate:
344 kfree(drvdata->states);
345err_memgpio:
346 kfree(drvdata->gpios);
347err_name:
348 kfree(drvdata->desc.name);
349err:
350 return ret;
351}
352
353static int gpio_regulator_remove(struct platform_device *pdev)
354{
355 struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
356
357 regulator_unregister(drvdata->dev);
358
359 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
360
361 kfree(drvdata->states);
362 kfree(drvdata->gpios);
363
364 kfree(drvdata->desc.name);
365
366 return 0;
367}
368
369#if defined(CONFIG_OF)
370static const struct of_device_id regulator_gpio_of_match[] = {
371 { .compatible = "regulator-gpio", },
372 {},
373};
374#endif
375
376static struct platform_driver gpio_regulator_driver = {
377 .probe = gpio_regulator_probe,
378 .remove = gpio_regulator_remove,
379 .driver = {
380 .name = "gpio-regulator",
381 .owner = THIS_MODULE,
382 .of_match_table = of_match_ptr(regulator_gpio_of_match),
383 },
384};
385
386static int __init gpio_regulator_init(void)
387{
388 return platform_driver_register(&gpio_regulator_driver);
389}
390subsys_initcall(gpio_regulator_init);
391
392static void __exit gpio_regulator_exit(void)
393{
394 platform_driver_unregister(&gpio_regulator_driver);
395}
396module_exit(gpio_regulator_exit);
397
398MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
399MODULE_DESCRIPTION("gpio voltage regulator");
400MODULE_LICENSE("GPL");
401MODULE_ALIAS("platform:gpio-regulator");
402
