This source file includes following definitions.
- gpio_regulator_get_value
- gpio_regulator_set_voltage
- gpio_regulator_list_voltage
- gpio_regulator_set_current_limit
- of_get_gpio_regulator_config
- gpio_regulator_probe
- gpio_regulator_init
- gpio_regulator_exit
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21 #include <linux/err.h>
22 #include <linux/mutex.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/regulator/driver.h>
26 #include <linux/regulator/machine.h>
27 #include <linux/regulator/of_regulator.h>
28 #include <linux/regulator/gpio-regulator.h>
29 #include <linux/gpio/consumer.h>
30 #include <linux/slab.h>
31 #include <linux/of.h>
32
33 struct gpio_regulator_data {
34 struct regulator_desc desc;
35
36 struct gpio_desc **gpiods;
37 int nr_gpios;
38
39 struct gpio_regulator_state *states;
40 int nr_states;
41
42 int state;
43 };
44
45 static int gpio_regulator_get_value(struct regulator_dev *dev)
46 {
47 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
48 int ptr;
49
50 for (ptr = 0; ptr < data->nr_states; ptr++)
51 if (data->states[ptr].gpios == data->state)
52 return data->states[ptr].value;
53
54 return -EINVAL;
55 }
56
57 static int gpio_regulator_set_voltage(struct regulator_dev *dev,
58 int min_uV, int max_uV,
59 unsigned *selector)
60 {
61 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
62 int ptr, target = 0, state, best_val = INT_MAX;
63
64 for (ptr = 0; ptr < data->nr_states; ptr++)
65 if (data->states[ptr].value < best_val &&
66 data->states[ptr].value >= min_uV &&
67 data->states[ptr].value <= max_uV) {
68 target = data->states[ptr].gpios;
69 best_val = data->states[ptr].value;
70 if (selector)
71 *selector = ptr;
72 }
73
74 if (best_val == INT_MAX)
75 return -EINVAL;
76
77 for (ptr = 0; ptr < data->nr_gpios; ptr++) {
78 state = (target & (1 << ptr)) >> ptr;
79 gpiod_set_value_cansleep(data->gpiods[ptr], state);
80 }
81 data->state = target;
82
83 return 0;
84 }
85
86 static int gpio_regulator_list_voltage(struct regulator_dev *dev,
87 unsigned selector)
88 {
89 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
90
91 if (selector >= data->nr_states)
92 return -EINVAL;
93
94 return data->states[selector].value;
95 }
96
97 static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
98 int min_uA, int max_uA)
99 {
100 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
101 int ptr, target = 0, state, best_val = 0;
102
103 for (ptr = 0; ptr < data->nr_states; ptr++)
104 if (data->states[ptr].value > best_val &&
105 data->states[ptr].value >= min_uA &&
106 data->states[ptr].value <= max_uA) {
107 target = data->states[ptr].gpios;
108 best_val = data->states[ptr].value;
109 }
110
111 if (best_val == 0)
112 return -EINVAL;
113
114 for (ptr = 0; ptr < data->nr_gpios; ptr++) {
115 state = (target & (1 << ptr)) >> ptr;
116 gpiod_set_value_cansleep(data->gpiods[ptr], state);
117 }
118 data->state = target;
119
120 return 0;
121 }
122
123 static const struct regulator_ops gpio_regulator_voltage_ops = {
124 .get_voltage = gpio_regulator_get_value,
125 .set_voltage = gpio_regulator_set_voltage,
126 .list_voltage = gpio_regulator_list_voltage,
127 };
128
129 static struct gpio_regulator_config *
130 of_get_gpio_regulator_config(struct device *dev, struct device_node *np,
131 const struct regulator_desc *desc)
132 {
133 struct gpio_regulator_config *config;
134 const char *regtype;
135 int proplen, i;
136 int ngpios;
137 int ret;
138
139 config = devm_kzalloc(dev,
140 sizeof(struct gpio_regulator_config),
141 GFP_KERNEL);
142 if (!config)
143 return ERR_PTR(-ENOMEM);
144
145 config->init_data = of_get_regulator_init_data(dev, np, desc);
146 if (!config->init_data)
147 return ERR_PTR(-EINVAL);
148
149 config->supply_name = config->init_data->constraints.name;
150
151 if (of_property_read_bool(np, "enable-at-boot"))
152 config->enabled_at_boot = true;
153
154 of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
155
156
157 ngpios = gpiod_count(dev, NULL);
158 if (ngpios > 0) {
159 config->gflags = devm_kzalloc(dev,
160 sizeof(enum gpiod_flags)
161 * ngpios,
162 GFP_KERNEL);
163 if (!config->gflags)
164 return ERR_PTR(-ENOMEM);
165
166 for (i = 0; i < ngpios; i++) {
167 u32 val;
168
169 ret = of_property_read_u32_index(np, "gpios-states", i,
170 &val);
171
172
173 if (ret)
174 config->gflags[i] = GPIOD_OUT_HIGH;
175 else
176 config->gflags[i] =
177 val ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
178 }
179 }
180 config->ngpios = ngpios;
181
182
183 proplen = of_property_count_u32_elems(np, "states");
184 if (proplen < 0) {
185 dev_err(dev, "No 'states' property found\n");
186 return ERR_PTR(-EINVAL);
187 }
188
189 config->states = devm_kcalloc(dev,
190 proplen / 2,
191 sizeof(struct gpio_regulator_state),
192 GFP_KERNEL);
193 if (!config->states)
194 return ERR_PTR(-ENOMEM);
195
196 for (i = 0; i < proplen / 2; i++) {
197 of_property_read_u32_index(np, "states", i * 2,
198 &config->states[i].value);
199 of_property_read_u32_index(np, "states", i * 2 + 1,
200 &config->states[i].gpios);
201 }
202 config->nr_states = i;
203
204 config->type = REGULATOR_VOLTAGE;
205 ret = of_property_read_string(np, "regulator-type", ®type);
206 if (ret >= 0) {
207 if (!strncmp("voltage", regtype, 7))
208 config->type = REGULATOR_VOLTAGE;
209 else if (!strncmp("current", regtype, 7))
210 config->type = REGULATOR_CURRENT;
211 else
212 dev_warn(dev, "Unknown regulator-type '%s'\n",
213 regtype);
214 }
215
216 return config;
217 }
218
219 static const struct regulator_ops gpio_regulator_current_ops = {
220 .get_current_limit = gpio_regulator_get_value,
221 .set_current_limit = gpio_regulator_set_current_limit,
222 };
223
224 static int gpio_regulator_probe(struct platform_device *pdev)
225 {
226 struct device *dev = &pdev->dev;
227 struct gpio_regulator_config *config = dev_get_platdata(dev);
228 struct device_node *np = dev->of_node;
229 struct gpio_regulator_data *drvdata;
230 struct regulator_config cfg = { };
231 struct regulator_dev *rdev;
232 enum gpiod_flags gflags;
233 int ptr, ret, state, i;
234
235 drvdata = devm_kzalloc(dev, sizeof(struct gpio_regulator_data),
236 GFP_KERNEL);
237 if (drvdata == NULL)
238 return -ENOMEM;
239
240 if (np) {
241 config = of_get_gpio_regulator_config(dev, np,
242 &drvdata->desc);
243 if (IS_ERR(config))
244 return PTR_ERR(config);
245 }
246
247 drvdata->desc.name = devm_kstrdup(dev, config->supply_name, GFP_KERNEL);
248 if (drvdata->desc.name == NULL) {
249 dev_err(dev, "Failed to allocate supply name\n");
250 return -ENOMEM;
251 }
252
253 drvdata->gpiods = devm_kzalloc(dev, sizeof(struct gpio_desc *),
254 GFP_KERNEL);
255 if (!drvdata->gpiods)
256 return -ENOMEM;
257 for (i = 0; i < config->ngpios; i++) {
258 drvdata->gpiods[i] = devm_gpiod_get_index(dev,
259 NULL,
260 i,
261 config->gflags[i]);
262 if (IS_ERR(drvdata->gpiods[i]))
263 return PTR_ERR(drvdata->gpiods[i]);
264
265 gpiod_set_consumer_name(drvdata->gpiods[i], drvdata->desc.name);
266 }
267 drvdata->nr_gpios = config->ngpios;
268
269 drvdata->states = devm_kmemdup(dev,
270 config->states,
271 config->nr_states *
272 sizeof(struct gpio_regulator_state),
273 GFP_KERNEL);
274 if (drvdata->states == NULL) {
275 dev_err(dev, "Failed to allocate state data\n");
276 return -ENOMEM;
277 }
278 drvdata->nr_states = config->nr_states;
279
280 drvdata->desc.owner = THIS_MODULE;
281 drvdata->desc.enable_time = config->startup_delay;
282
283
284 switch (config->type) {
285 case REGULATOR_VOLTAGE:
286 drvdata->desc.type = REGULATOR_VOLTAGE;
287 drvdata->desc.ops = &gpio_regulator_voltage_ops;
288 drvdata->desc.n_voltages = config->nr_states;
289 break;
290 case REGULATOR_CURRENT:
291 drvdata->desc.type = REGULATOR_CURRENT;
292 drvdata->desc.ops = &gpio_regulator_current_ops;
293 break;
294 default:
295 dev_err(dev, "No regulator type set\n");
296 return -EINVAL;
297 }
298
299
300 state = 0;
301 for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
302 if (config->gflags[ptr] == GPIOD_OUT_HIGH)
303 state |= (1 << ptr);
304 }
305 drvdata->state = state;
306
307 cfg.dev = dev;
308 cfg.init_data = config->init_data;
309 cfg.driver_data = drvdata;
310 cfg.of_node = np;
311
312
313
314
315
316 if (config->enabled_at_boot)
317 gflags = GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE;
318 else
319 gflags = GPIOD_OUT_LOW | GPIOD_FLAGS_BIT_NONEXCLUSIVE;
320
321 cfg.ena_gpiod = gpiod_get_optional(dev, "enable", gflags);
322 if (IS_ERR(cfg.ena_gpiod))
323 return PTR_ERR(cfg.ena_gpiod);
324
325 rdev = devm_regulator_register(dev, &drvdata->desc, &cfg);
326 if (IS_ERR(rdev)) {
327 ret = PTR_ERR(rdev);
328 dev_err(dev, "Failed to register regulator: %d\n", ret);
329 return ret;
330 }
331
332 platform_set_drvdata(pdev, drvdata);
333
334 return 0;
335 }
336
337 #if defined(CONFIG_OF)
338 static const struct of_device_id regulator_gpio_of_match[] = {
339 { .compatible = "regulator-gpio", },
340 {},
341 };
342 MODULE_DEVICE_TABLE(of, regulator_gpio_of_match);
343 #endif
344
345 static struct platform_driver gpio_regulator_driver = {
346 .probe = gpio_regulator_probe,
347 .driver = {
348 .name = "gpio-regulator",
349 .of_match_table = of_match_ptr(regulator_gpio_of_match),
350 },
351 };
352
353 static int __init gpio_regulator_init(void)
354 {
355 return platform_driver_register(&gpio_regulator_driver);
356 }
357 subsys_initcall(gpio_regulator_init);
358
359 static void __exit gpio_regulator_exit(void)
360 {
361 platform_driver_unregister(&gpio_regulator_driver);
362 }
363 module_exit(gpio_regulator_exit);
364
365 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
366 MODULE_DESCRIPTION("gpio voltage regulator");
367 MODULE_LICENSE("GPL");
368 MODULE_ALIAS("platform:gpio-regulator");