1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * gpio-regulator.c |
4 | * |
5 | * Copyright 2011 Heiko Stuebner <heiko@sntech.de> |
6 | * |
7 | * based on fixed.c |
8 | * |
9 | * Copyright 2008 Wolfson Microelectronics PLC. |
10 | * |
11 | * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> |
12 | * |
13 | * Copyright (c) 2009 Nokia Corporation |
14 | * Roger Quadros <ext-roger.quadros@nokia.com> |
15 | * |
16 | * This is useful for systems with mixed controllable and |
17 | * non-controllable regulators, as well as for allowing testing on |
18 | * systems with no controllable regulators. |
19 | */ |
20 | |
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(rdev: 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(rdev: 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(desc: data->gpiods[ptr], value: 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(rdev: 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(rdev: 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(desc: data->gpiods[ptr], value: 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 | size: sizeof(struct gpio_regulator_config), |
141 | GFP_KERNEL); |
142 | if (!config) |
143 | return ERR_PTR(error: -ENOMEM); |
144 | |
145 | config->init_data = of_get_regulator_init_data(dev, node: np, desc); |
146 | if (!config->init_data) |
147 | return ERR_PTR(error: -EINVAL); |
148 | |
149 | config->supply_name = config->init_data->constraints.name; |
150 | |
151 | if (config->init_data->constraints.boot_on) |
152 | config->enabled_at_boot = true; |
153 | |
154 | /* |
155 | * Do not use: undocumented device tree property. |
156 | * This is kept around solely for device tree ABI stability. |
157 | */ |
158 | if (of_property_read_bool(np, propname: "enable-at-boot" )) |
159 | config->enabled_at_boot = true; |
160 | |
161 | of_property_read_u32(np, propname: "startup-delay-us" , out_value: &config->startup_delay); |
162 | |
163 | /* Fetch GPIO init levels */ |
164 | ngpios = gpiod_count(dev, NULL); |
165 | if (ngpios > 0) { |
166 | config->gflags = devm_kzalloc(dev, |
167 | size: sizeof(enum gpiod_flags) |
168 | * ngpios, |
169 | GFP_KERNEL); |
170 | if (!config->gflags) |
171 | return ERR_PTR(error: -ENOMEM); |
172 | |
173 | for (i = 0; i < ngpios; i++) { |
174 | u32 val; |
175 | |
176 | ret = of_property_read_u32_index(np, propname: "gpios-states" , index: i, |
177 | out_value: &val); |
178 | |
179 | /* Default to high per specification */ |
180 | if (ret) |
181 | config->gflags[i] = GPIOD_OUT_HIGH; |
182 | else |
183 | config->gflags[i] = |
184 | val ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW; |
185 | } |
186 | } |
187 | config->ngpios = ngpios; |
188 | |
189 | /* Fetch states. */ |
190 | proplen = of_property_count_u32_elems(np, propname: "states" ); |
191 | if (proplen < 0) { |
192 | dev_err(dev, "No 'states' property found\n" ); |
193 | return ERR_PTR(error: -EINVAL); |
194 | } |
195 | |
196 | config->states = devm_kcalloc(dev, |
197 | n: proplen / 2, |
198 | size: sizeof(struct gpio_regulator_state), |
199 | GFP_KERNEL); |
200 | if (!config->states) |
201 | return ERR_PTR(error: -ENOMEM); |
202 | |
203 | for (i = 0; i < proplen / 2; i++) { |
204 | of_property_read_u32_index(np, propname: "states" , index: i * 2, |
205 | out_value: &config->states[i].value); |
206 | of_property_read_u32_index(np, propname: "states" , index: i * 2 + 1, |
207 | out_value: &config->states[i].gpios); |
208 | } |
209 | config->nr_states = i; |
210 | |
211 | config->type = REGULATOR_VOLTAGE; |
212 | ret = of_property_read_string(np, propname: "regulator-type" , out_string: ®type); |
213 | if (ret >= 0) { |
214 | if (!strncmp("voltage" , regtype, 7)) |
215 | config->type = REGULATOR_VOLTAGE; |
216 | else if (!strncmp("current" , regtype, 7)) |
217 | config->type = REGULATOR_CURRENT; |
218 | else |
219 | dev_warn(dev, "Unknown regulator-type '%s'\n" , |
220 | regtype); |
221 | } |
222 | |
223 | if (of_property_present(np, propname: "vin-supply" )) |
224 | config->input_supply = "vin" ; |
225 | |
226 | return config; |
227 | } |
228 | |
229 | static const struct regulator_ops gpio_regulator_current_ops = { |
230 | .get_current_limit = gpio_regulator_get_value, |
231 | .set_current_limit = gpio_regulator_set_current_limit, |
232 | }; |
233 | |
234 | static int gpio_regulator_probe(struct platform_device *pdev) |
235 | { |
236 | struct device *dev = &pdev->dev; |
237 | struct gpio_regulator_config *config = dev_get_platdata(dev); |
238 | struct device_node *np = dev->of_node; |
239 | struct gpio_regulator_data *drvdata; |
240 | struct regulator_config cfg = { }; |
241 | struct regulator_dev *rdev; |
242 | enum gpiod_flags gflags; |
243 | int ptr, ret, state, i; |
244 | |
245 | drvdata = devm_kzalloc(dev, size: sizeof(struct gpio_regulator_data), |
246 | GFP_KERNEL); |
247 | if (drvdata == NULL) |
248 | return -ENOMEM; |
249 | |
250 | if (np) { |
251 | config = of_get_gpio_regulator_config(dev, np, |
252 | desc: &drvdata->desc); |
253 | if (IS_ERR(ptr: config)) |
254 | return PTR_ERR(ptr: config); |
255 | } |
256 | |
257 | drvdata->desc.name = devm_kstrdup(dev, s: config->supply_name, GFP_KERNEL); |
258 | if (drvdata->desc.name == NULL) { |
259 | dev_err(dev, "Failed to allocate supply name\n" ); |
260 | return -ENOMEM; |
261 | } |
262 | |
263 | drvdata->gpiods = devm_kzalloc(dev, size: sizeof(struct gpio_desc *), |
264 | GFP_KERNEL); |
265 | |
266 | if (config->input_supply) { |
267 | drvdata->desc.supply_name = devm_kstrdup(dev: &pdev->dev, |
268 | s: config->input_supply, |
269 | GFP_KERNEL); |
270 | if (!drvdata->desc.supply_name) { |
271 | dev_err(&pdev->dev, |
272 | "Failed to allocate input supply\n" ); |
273 | return -ENOMEM; |
274 | } |
275 | } |
276 | |
277 | if (!drvdata->gpiods) |
278 | return -ENOMEM; |
279 | for (i = 0; i < config->ngpios; i++) { |
280 | drvdata->gpiods[i] = devm_gpiod_get_index(dev, |
281 | NULL, |
282 | idx: i, |
283 | flags: config->gflags[i]); |
284 | if (IS_ERR(ptr: drvdata->gpiods[i])) |
285 | return PTR_ERR(ptr: drvdata->gpiods[i]); |
286 | /* This is good to know */ |
287 | gpiod_set_consumer_name(desc: drvdata->gpiods[i], name: drvdata->desc.name); |
288 | } |
289 | drvdata->nr_gpios = config->ngpios; |
290 | |
291 | drvdata->states = devm_kmemdup(dev, |
292 | src: config->states, |
293 | len: config->nr_states * |
294 | sizeof(struct gpio_regulator_state), |
295 | GFP_KERNEL); |
296 | if (drvdata->states == NULL) { |
297 | dev_err(dev, "Failed to allocate state data\n" ); |
298 | return -ENOMEM; |
299 | } |
300 | drvdata->nr_states = config->nr_states; |
301 | |
302 | drvdata->desc.owner = THIS_MODULE; |
303 | drvdata->desc.enable_time = config->startup_delay; |
304 | |
305 | /* handle regulator type*/ |
306 | switch (config->type) { |
307 | case REGULATOR_VOLTAGE: |
308 | drvdata->desc.type = REGULATOR_VOLTAGE; |
309 | drvdata->desc.ops = &gpio_regulator_voltage_ops; |
310 | drvdata->desc.n_voltages = config->nr_states; |
311 | break; |
312 | case REGULATOR_CURRENT: |
313 | drvdata->desc.type = REGULATOR_CURRENT; |
314 | drvdata->desc.ops = &gpio_regulator_current_ops; |
315 | break; |
316 | default: |
317 | dev_err(dev, "No regulator type set\n" ); |
318 | return -EINVAL; |
319 | } |
320 | |
321 | /* build initial state from gpio init data. */ |
322 | state = 0; |
323 | for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) { |
324 | if (config->gflags[ptr] == GPIOD_OUT_HIGH) |
325 | state |= (1 << ptr); |
326 | } |
327 | drvdata->state = state; |
328 | |
329 | cfg.dev = dev; |
330 | cfg.init_data = config->init_data; |
331 | cfg.driver_data = drvdata; |
332 | cfg.of_node = np; |
333 | |
334 | /* |
335 | * The signal will be inverted by the GPIO core if flagged so in the |
336 | * descriptor. |
337 | */ |
338 | if (config->enabled_at_boot) |
339 | gflags = GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE; |
340 | else |
341 | gflags = GPIOD_OUT_LOW | GPIOD_FLAGS_BIT_NONEXCLUSIVE; |
342 | |
343 | cfg.ena_gpiod = gpiod_get_optional(dev, con_id: "enable" , flags: gflags); |
344 | if (IS_ERR(ptr: cfg.ena_gpiod)) |
345 | return PTR_ERR(ptr: cfg.ena_gpiod); |
346 | |
347 | rdev = devm_regulator_register(dev, regulator_desc: &drvdata->desc, config: &cfg); |
348 | if (IS_ERR(ptr: rdev)) { |
349 | ret = PTR_ERR(ptr: rdev); |
350 | dev_err(dev, "Failed to register regulator: %d\n" , ret); |
351 | return ret; |
352 | } |
353 | |
354 | platform_set_drvdata(pdev, data: drvdata); |
355 | |
356 | return 0; |
357 | } |
358 | |
359 | #if defined(CONFIG_OF) |
360 | static const struct of_device_id regulator_gpio_of_match[] = { |
361 | { .compatible = "regulator-gpio" , }, |
362 | {}, |
363 | }; |
364 | MODULE_DEVICE_TABLE(of, regulator_gpio_of_match); |
365 | #endif |
366 | |
367 | static struct platform_driver gpio_regulator_driver = { |
368 | .probe = gpio_regulator_probe, |
369 | .driver = { |
370 | .name = "gpio-regulator" , |
371 | .probe_type = PROBE_PREFER_ASYNCHRONOUS, |
372 | .of_match_table = of_match_ptr(regulator_gpio_of_match), |
373 | }, |
374 | }; |
375 | |
376 | static int __init gpio_regulator_init(void) |
377 | { |
378 | return platform_driver_register(&gpio_regulator_driver); |
379 | } |
380 | subsys_initcall(gpio_regulator_init); |
381 | |
382 | static void __exit gpio_regulator_exit(void) |
383 | { |
384 | platform_driver_unregister(&gpio_regulator_driver); |
385 | } |
386 | module_exit(gpio_regulator_exit); |
387 | |
388 | MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>" ); |
389 | MODULE_DESCRIPTION("gpio voltage regulator" ); |
390 | MODULE_LICENSE("GPL" ); |
391 | MODULE_ALIAS("platform:gpio-regulator" ); |
392 | |