1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * fixed.c
4 *
5 * Copyright 2008 Wolfson Microelectronics PLC.
6 *
7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 *
9 * Copyright (c) 2009 Nokia Corporation
10 * Roger Quadros <ext-roger.quadros@nokia.com>
11 *
12 * This is useful for systems with mixed controllable and
13 * non-controllable regulators, as well as for allowing testing on
14 * systems with no controllable regulators.
15 */
16
17 #include <linux/err.h>
18 #include <linux/mutex.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/pm_domain.h>
22 #include <linux/pm_opp.h>
23 #include <linux/regulator/driver.h>
24 #include <linux/regulator/fixed.h>
25 #include <linux/gpio/consumer.h>
26 #include <linux/slab.h>
27 #include <linux/of.h>
28 #include <linux/of_device.h>
29 #include <linux/regulator/of_regulator.h>
30 #include <linux/regulator/machine.h>
31 #include <linux/clk.h>
32
33
34 struct fixed_voltage_data {
35 struct regulator_desc desc;
36 struct regulator_dev *dev;
37
38 struct clk *enable_clock;
39 unsigned int enable_counter;
40 int performance_state;
41 };
42
43 struct fixed_dev_type {
44 bool has_enable_clock;
45 bool has_performance_state;
46 };
47
reg_clock_enable(struct regulator_dev * rdev)48 static int reg_clock_enable(struct regulator_dev *rdev)
49 {
50 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
51 int ret = 0;
52
53 ret = clk_prepare_enable(priv->enable_clock);
54 if (ret)
55 return ret;
56
57 priv->enable_counter++;
58
59 return ret;
60 }
61
reg_clock_disable(struct regulator_dev * rdev)62 static int reg_clock_disable(struct regulator_dev *rdev)
63 {
64 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
65
66 clk_disable_unprepare(priv->enable_clock);
67 priv->enable_counter--;
68
69 return 0;
70 }
71
reg_domain_enable(struct regulator_dev * rdev)72 static int reg_domain_enable(struct regulator_dev *rdev)
73 {
74 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
75 struct device *dev = rdev->dev.parent;
76 int ret;
77
78 ret = dev_pm_genpd_set_performance_state(dev, priv->performance_state);
79 if (ret)
80 return ret;
81
82 priv->enable_counter++;
83
84 return ret;
85 }
86
reg_domain_disable(struct regulator_dev * rdev)87 static int reg_domain_disable(struct regulator_dev *rdev)
88 {
89 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
90 struct device *dev = rdev->dev.parent;
91
92 priv->enable_counter--;
93
94 return dev_pm_genpd_set_performance_state(dev, 0);
95 }
96
reg_is_enabled(struct regulator_dev * rdev)97 static int reg_is_enabled(struct regulator_dev *rdev)
98 {
99 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
100
101 return priv->enable_counter > 0;
102 }
103
104
105 /**
106 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
107 * @dev: device requesting for fixed_voltage_config
108 * @desc: regulator description
109 *
110 * Populates fixed_voltage_config structure by extracting data from device
111 * tree node, returns a pointer to the populated structure of NULL if memory
112 * alloc fails.
113 */
114 static struct fixed_voltage_config *
of_get_fixed_voltage_config(struct device * dev,const struct regulator_desc * desc)115 of_get_fixed_voltage_config(struct device *dev,
116 const struct regulator_desc *desc)
117 {
118 struct fixed_voltage_config *config;
119 struct device_node *np = dev->of_node;
120 struct regulator_init_data *init_data;
121
122 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
123 GFP_KERNEL);
124 if (!config)
125 return ERR_PTR(-ENOMEM);
126
127 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc);
128 if (!config->init_data)
129 return ERR_PTR(-EINVAL);
130
131 init_data = config->init_data;
132 init_data->constraints.apply_uV = 0;
133
134 config->supply_name = init_data->constraints.name;
135 if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
136 config->microvolts = init_data->constraints.min_uV;
137 } else {
138 dev_err(dev,
139 "Fixed regulator specified with variable voltages\n");
140 return ERR_PTR(-EINVAL);
141 }
142
143 if (init_data->constraints.boot_on)
144 config->enabled_at_boot = true;
145
146 of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
147 of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay);
148
149 if (of_find_property(np, "vin-supply", NULL))
150 config->input_supply = "vin";
151
152 return config;
153 }
154
155 static const struct regulator_ops fixed_voltage_ops = {
156 };
157
158 static const struct regulator_ops fixed_voltage_clkenabled_ops = {
159 .enable = reg_clock_enable,
160 .disable = reg_clock_disable,
161 .is_enabled = reg_is_enabled,
162 };
163
164 static const struct regulator_ops fixed_voltage_domain_ops = {
165 .enable = reg_domain_enable,
166 .disable = reg_domain_disable,
167 .is_enabled = reg_is_enabled,
168 };
169
reg_fixed_voltage_probe(struct platform_device * pdev)170 static int reg_fixed_voltage_probe(struct platform_device *pdev)
171 {
172 struct device *dev = &pdev->dev;
173 struct fixed_voltage_config *config;
174 struct fixed_voltage_data *drvdata;
175 const struct fixed_dev_type *drvtype = of_device_get_match_data(dev);
176 struct regulator_config cfg = { };
177 enum gpiod_flags gflags;
178 int ret;
179
180 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
181 GFP_KERNEL);
182 if (!drvdata)
183 return -ENOMEM;
184
185 if (pdev->dev.of_node) {
186 config = of_get_fixed_voltage_config(&pdev->dev,
187 &drvdata->desc);
188 if (IS_ERR(config))
189 return PTR_ERR(config);
190 } else {
191 config = dev_get_platdata(&pdev->dev);
192 }
193
194 if (!config)
195 return -ENOMEM;
196
197 drvdata->desc.name = devm_kstrdup(&pdev->dev,
198 config->supply_name,
199 GFP_KERNEL);
200 if (drvdata->desc.name == NULL) {
201 dev_err(&pdev->dev, "Failed to allocate supply name\n");
202 return -ENOMEM;
203 }
204 drvdata->desc.type = REGULATOR_VOLTAGE;
205 drvdata->desc.owner = THIS_MODULE;
206
207 if (drvtype && drvtype->has_enable_clock) {
208 drvdata->desc.ops = &fixed_voltage_clkenabled_ops;
209
210 drvdata->enable_clock = devm_clk_get(dev, NULL);
211 if (IS_ERR(drvdata->enable_clock)) {
212 dev_err(dev, "Can't get enable-clock from devicetree\n");
213 return -ENOENT;
214 }
215 } else if (drvtype && drvtype->has_performance_state) {
216 drvdata->desc.ops = &fixed_voltage_domain_ops;
217
218 drvdata->performance_state = of_get_required_opp_performance_state(dev->of_node, 0);
219 if (drvdata->performance_state < 0) {
220 dev_err(dev, "Can't get performance state from devicetree\n");
221 return drvdata->performance_state;
222 }
223 } else {
224 drvdata->desc.ops = &fixed_voltage_ops;
225 }
226
227 drvdata->desc.enable_time = config->startup_delay;
228 drvdata->desc.off_on_delay = config->off_on_delay;
229
230 if (config->input_supply) {
231 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
232 config->input_supply,
233 GFP_KERNEL);
234 if (!drvdata->desc.supply_name) {
235 dev_err(&pdev->dev,
236 "Failed to allocate input supply\n");
237 return -ENOMEM;
238 }
239 }
240
241 if (config->microvolts)
242 drvdata->desc.n_voltages = 1;
243
244 drvdata->desc.fixed_uV = config->microvolts;
245
246 /*
247 * The signal will be inverted by the GPIO core if flagged so in the
248 * descriptor.
249 */
250 if (config->enabled_at_boot)
251 gflags = GPIOD_OUT_HIGH;
252 else
253 gflags = GPIOD_OUT_LOW;
254
255 /*
256 * Some fixed regulators share the enable line between two
257 * regulators which makes it necessary to get a handle on the
258 * same descriptor for two different consumers. This will get
259 * the GPIO descriptor, but only the first call will initialize
260 * it so any flags such as inversion or open drain will only
261 * be set up by the first caller and assumed identical on the
262 * next caller.
263 *
264 * FIXME: find a better way to deal with this.
265 */
266 gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
267
268 /*
269 * Do not use devm* here: the regulator core takes over the
270 * lifecycle management of the GPIO descriptor.
271 */
272 cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags);
273 if (IS_ERR(cfg.ena_gpiod))
274 return PTR_ERR(cfg.ena_gpiod);
275
276 cfg.dev = &pdev->dev;
277 cfg.init_data = config->init_data;
278 cfg.driver_data = drvdata;
279 cfg.of_node = pdev->dev.of_node;
280
281 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
282 &cfg);
283 if (IS_ERR(drvdata->dev)) {
284 ret = PTR_ERR(drvdata->dev);
285 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
286 return ret;
287 }
288
289 platform_set_drvdata(pdev, drvdata);
290
291 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
292 drvdata->desc.fixed_uV);
293
294 return 0;
295 }
296
297 #if defined(CONFIG_OF)
298 static const struct fixed_dev_type fixed_voltage_data = {
299 .has_enable_clock = false,
300 };
301
302 static const struct fixed_dev_type fixed_clkenable_data = {
303 .has_enable_clock = true,
304 };
305
306 static const struct fixed_dev_type fixed_domain_data = {
307 .has_performance_state = true,
308 };
309
310 static const struct of_device_id fixed_of_match[] = {
311 {
312 .compatible = "regulator-fixed",
313 .data = &fixed_voltage_data,
314 },
315 {
316 .compatible = "regulator-fixed-clock",
317 .data = &fixed_clkenable_data,
318 },
319 {
320 .compatible = "regulator-fixed-domain",
321 .data = &fixed_domain_data,
322 },
323 {
324 },
325 };
326 MODULE_DEVICE_TABLE(of, fixed_of_match);
327 #endif
328
329 static struct platform_driver regulator_fixed_voltage_driver = {
330 .probe = reg_fixed_voltage_probe,
331 .driver = {
332 .name = "reg-fixed-voltage",
333 .of_match_table = of_match_ptr(fixed_of_match),
334 },
335 };
336
regulator_fixed_voltage_init(void)337 static int __init regulator_fixed_voltage_init(void)
338 {
339 return platform_driver_register(®ulator_fixed_voltage_driver);
340 }
341 subsys_initcall(regulator_fixed_voltage_init);
342
regulator_fixed_voltage_exit(void)343 static void __exit regulator_fixed_voltage_exit(void)
344 {
345 platform_driver_unregister(®ulator_fixed_voltage_driver);
346 }
347 module_exit(regulator_fixed_voltage_exit);
348
349 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
350 MODULE_DESCRIPTION("Fixed voltage regulator");
351 MODULE_LICENSE("GPL");
352 MODULE_ALIAS("platform:reg-fixed-voltage");
353