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1/*
2 * fixed.c
3 *
4 * Copyright 2008 Wolfson Microelectronics PLC.
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * Copyright (c) 2009 Nokia Corporation
9 * Roger Quadros <ext-roger.quadros@nokia.com>
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation; either version 2 of the
14 * License, or (at your option) any later version.
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/platform_device.h>
24#include <linux/regulator/driver.h>
25#include <linux/regulator/fixed.h>
26#include <linux/gpio.h>
27#include <linux/delay.h>
28#include <linux/slab.h>
29
30struct fixed_voltage_data {
31 struct regulator_desc desc;
32 struct regulator_dev *dev;
33 int microvolts;
34 int gpio;
35 unsigned startup_delay;
36 bool enable_high;
37 bool is_enabled;
38};
39
40static int fixed_voltage_is_enabled(struct regulator_dev *dev)
41{
42 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
43
44 return data->is_enabled;
45}
46
47static int fixed_voltage_enable(struct regulator_dev *dev)
48{
49 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
50
51 if (gpio_is_valid(data->gpio)) {
52 gpio_set_value_cansleep(data->gpio, data->enable_high);
53 data->is_enabled = true;
54 }
55
56 return 0;
57}
58
59static int fixed_voltage_disable(struct regulator_dev *dev)
60{
61 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
62
63 if (gpio_is_valid(data->gpio)) {
64 gpio_set_value_cansleep(data->gpio, !data->enable_high);
65 data->is_enabled = false;
66 }
67
68 return 0;
69}
70
71static int fixed_voltage_enable_time(struct regulator_dev *dev)
72{
73 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
74
75 return data->startup_delay;
76}
77
78static int fixed_voltage_get_voltage(struct regulator_dev *dev)
79{
80 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
81
82 return data->microvolts;
83}
84
85static int fixed_voltage_list_voltage(struct regulator_dev *dev,
86 unsigned selector)
87{
88 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
89
90 if (selector != 0)
91 return -EINVAL;
92
93 return data->microvolts;
94}
95
96static struct regulator_ops fixed_voltage_ops = {
97 .is_enabled = fixed_voltage_is_enabled,
98 .enable = fixed_voltage_enable,
99 .disable = fixed_voltage_disable,
100 .enable_time = fixed_voltage_enable_time,
101 .get_voltage = fixed_voltage_get_voltage,
102 .list_voltage = fixed_voltage_list_voltage,
103};
104
105static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
106{
107 struct fixed_voltage_config *config = pdev->dev.platform_data;
108 struct fixed_voltage_data *drvdata;
109 int ret;
110
111 drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
112 if (drvdata == NULL) {
113 dev_err(&pdev->dev, "Failed to allocate device data\n");
114 ret = -ENOMEM;
115 goto err;
116 }
117
118 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
119 if (drvdata->desc.name == NULL) {
120 dev_err(&pdev->dev, "Failed to allocate supply name\n");
121 ret = -ENOMEM;
122 goto err;
123 }
124 drvdata->desc.type = REGULATOR_VOLTAGE;
125 drvdata->desc.owner = THIS_MODULE;
126 drvdata->desc.ops = &fixed_voltage_ops;
127 drvdata->desc.n_voltages = 1;
128
129 drvdata->microvolts = config->microvolts;
130 drvdata->gpio = config->gpio;
131 drvdata->startup_delay = config->startup_delay;
132
133 if (gpio_is_valid(config->gpio)) {
134 drvdata->enable_high = config->enable_high;
135
136 /* FIXME: Remove below print warning
137 *
138 * config->gpio must be set to -EINVAL by platform code if
139 * GPIO control is not required. However, early adopters
140 * not requiring GPIO control may forget to initialize
141 * config->gpio to -EINVAL. This will cause GPIO 0 to be used
142 * for GPIO control.
143 *
144 * This warning will be removed once there are a couple of users
145 * for this driver.
146 */
147 if (!config->gpio)
148 dev_warn(&pdev->dev,
149 "using GPIO 0 for regulator enable control\n");
150
151 ret = gpio_request(config->gpio, config->supply_name);
152 if (ret) {
153 dev_err(&pdev->dev,
154 "Could not obtain regulator enable GPIO %d: %d\n",
155 config->gpio, ret);
156 goto err_name;
157 }
158
159 /* set output direction without changing state
160 * to prevent glitch
161 */
162 drvdata->is_enabled = config->enabled_at_boot;
163 ret = drvdata->is_enabled ?
164 config->enable_high : !config->enable_high;
165
166 ret = gpio_direction_output(config->gpio, ret);
167 if (ret) {
168 dev_err(&pdev->dev,
169 "Could not configure regulator enable GPIO %d direction: %d\n",
170 config->gpio, ret);
171 goto err_gpio;
172 }
173
174 } else {
175 /* Regulator without GPIO control is considered
176 * always enabled
177 */
178 drvdata->is_enabled = true;
179 }
180
181 drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
182 config->init_data, drvdata);
183 if (IS_ERR(drvdata->dev)) {
184 ret = PTR_ERR(drvdata->dev);
185 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
186 goto err_gpio;
187 }
188
189 platform_set_drvdata(pdev, drvdata);
190
191 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
192 drvdata->microvolts);
193
194 return 0;
195
196err_gpio:
197 if (gpio_is_valid(config->gpio))
198 gpio_free(config->gpio);
199err_name:
200 kfree(drvdata->desc.name);
201err:
202 kfree(drvdata);
203 return ret;
204}
205
206static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
207{
208 struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
209
210 regulator_unregister(drvdata->dev);
211 if (gpio_is_valid(drvdata->gpio))
212 gpio_free(drvdata->gpio);
213 kfree(drvdata->desc.name);
214 kfree(drvdata);
215
216 return 0;
217}
218
219static struct platform_driver regulator_fixed_voltage_driver = {
220 .probe = reg_fixed_voltage_probe,
221 .remove = __devexit_p(reg_fixed_voltage_remove),
222 .driver = {
223 .name = "reg-fixed-voltage",
224 .owner = THIS_MODULE,
225 },
226};
227
228static int __init regulator_fixed_voltage_init(void)
229{
230 return platform_driver_register(®ulator_fixed_voltage_driver);
231}
232subsys_initcall(regulator_fixed_voltage_init);
233
234static void __exit regulator_fixed_voltage_exit(void)
235{
236 platform_driver_unregister(®ulator_fixed_voltage_driver);
237}
238module_exit(regulator_fixed_voltage_exit);
239
240MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
241MODULE_DESCRIPTION("Fixed voltage regulator");
242MODULE_LICENSE("GPL");
243MODULE_ALIAS("platform:reg-fixed-voltage");
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
34struct 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
43struct fixed_dev_type {
44 bool has_enable_clock;
45 bool has_performance_state;
46};
47
48static 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
62static 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
72static 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
87static 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 int ret;
92
93 ret = dev_pm_genpd_set_performance_state(dev, 0);
94 if (ret)
95 return ret;
96
97 priv->enable_counter--;
98
99 return 0;
100}
101
102static int reg_is_enabled(struct regulator_dev *rdev)
103{
104 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
105
106 return priv->enable_counter > 0;
107}
108
109
110/**
111 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
112 * @dev: device requesting for fixed_voltage_config
113 * @desc: regulator description
114 *
115 * Populates fixed_voltage_config structure by extracting data from device
116 * tree node, returns a pointer to the populated structure of NULL if memory
117 * alloc fails.
118 */
119static struct fixed_voltage_config *
120of_get_fixed_voltage_config(struct device *dev,
121 const struct regulator_desc *desc)
122{
123 struct fixed_voltage_config *config;
124 struct device_node *np = dev->of_node;
125 struct regulator_init_data *init_data;
126
127 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
128 GFP_KERNEL);
129 if (!config)
130 return ERR_PTR(-ENOMEM);
131
132 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc);
133 if (!config->init_data)
134 return ERR_PTR(-EINVAL);
135
136 init_data = config->init_data;
137 init_data->constraints.apply_uV = 0;
138
139 config->supply_name = init_data->constraints.name;
140 if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
141 config->microvolts = init_data->constraints.min_uV;
142 } else {
143 dev_err(dev,
144 "Fixed regulator specified with variable voltages\n");
145 return ERR_PTR(-EINVAL);
146 }
147
148 if (init_data->constraints.boot_on)
149 config->enabled_at_boot = true;
150
151 of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
152 of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay);
153
154 if (of_find_property(np, "vin-supply", NULL))
155 config->input_supply = "vin";
156
157 return config;
158}
159
160static const struct regulator_ops fixed_voltage_ops = {
161};
162
163static const struct regulator_ops fixed_voltage_clkenabled_ops = {
164 .enable = reg_clock_enable,
165 .disable = reg_clock_disable,
166 .is_enabled = reg_is_enabled,
167};
168
169static const struct regulator_ops fixed_voltage_domain_ops = {
170 .enable = reg_domain_enable,
171 .disable = reg_domain_disable,
172 .is_enabled = reg_is_enabled,
173};
174
175static int reg_fixed_voltage_probe(struct platform_device *pdev)
176{
177 struct device *dev = &pdev->dev;
178 struct fixed_voltage_config *config;
179 struct fixed_voltage_data *drvdata;
180 const struct fixed_dev_type *drvtype = of_device_get_match_data(dev);
181 struct regulator_config cfg = { };
182 enum gpiod_flags gflags;
183 int ret;
184
185 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
186 GFP_KERNEL);
187 if (!drvdata)
188 return -ENOMEM;
189
190 if (pdev->dev.of_node) {
191 config = of_get_fixed_voltage_config(&pdev->dev,
192 &drvdata->desc);
193 if (IS_ERR(config))
194 return PTR_ERR(config);
195 } else {
196 config = dev_get_platdata(&pdev->dev);
197 }
198
199 if (!config)
200 return -ENOMEM;
201
202 drvdata->desc.name = devm_kstrdup(&pdev->dev,
203 config->supply_name,
204 GFP_KERNEL);
205 if (drvdata->desc.name == NULL) {
206 dev_err(&pdev->dev, "Failed to allocate supply name\n");
207 return -ENOMEM;
208 }
209 drvdata->desc.type = REGULATOR_VOLTAGE;
210 drvdata->desc.owner = THIS_MODULE;
211
212 if (drvtype && drvtype->has_enable_clock) {
213 drvdata->desc.ops = &fixed_voltage_clkenabled_ops;
214
215 drvdata->enable_clock = devm_clk_get(dev, NULL);
216 if (IS_ERR(drvdata->enable_clock)) {
217 dev_err(dev, "Can't get enable-clock from devicetree\n");
218 return -ENOENT;
219 }
220 } else if (drvtype && drvtype->has_performance_state) {
221 drvdata->desc.ops = &fixed_voltage_domain_ops;
222
223 drvdata->performance_state = of_get_required_opp_performance_state(dev->of_node, 0);
224 if (drvdata->performance_state < 0) {
225 dev_err(dev, "Can't get performance state from devicetree\n");
226 return drvdata->performance_state;
227 }
228 } else {
229 drvdata->desc.ops = &fixed_voltage_ops;
230 }
231
232 drvdata->desc.enable_time = config->startup_delay;
233 drvdata->desc.off_on_delay = config->off_on_delay;
234
235 if (config->input_supply) {
236 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
237 config->input_supply,
238 GFP_KERNEL);
239 if (!drvdata->desc.supply_name) {
240 dev_err(&pdev->dev,
241 "Failed to allocate input supply\n");
242 return -ENOMEM;
243 }
244 }
245
246 if (config->microvolts)
247 drvdata->desc.n_voltages = 1;
248
249 drvdata->desc.fixed_uV = config->microvolts;
250
251 /*
252 * The signal will be inverted by the GPIO core if flagged so in the
253 * descriptor.
254 */
255 if (config->enabled_at_boot)
256 gflags = GPIOD_OUT_HIGH;
257 else
258 gflags = GPIOD_OUT_LOW;
259
260 /*
261 * Some fixed regulators share the enable line between two
262 * regulators which makes it necessary to get a handle on the
263 * same descriptor for two different consumers. This will get
264 * the GPIO descriptor, but only the first call will initialize
265 * it so any flags such as inversion or open drain will only
266 * be set up by the first caller and assumed identical on the
267 * next caller.
268 *
269 * FIXME: find a better way to deal with this.
270 */
271 gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
272
273 /*
274 * Do not use devm* here: the regulator core takes over the
275 * lifecycle management of the GPIO descriptor.
276 */
277 cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags);
278 if (IS_ERR(cfg.ena_gpiod))
279 return dev_err_probe(&pdev->dev, PTR_ERR(cfg.ena_gpiod),
280 "can't get GPIO\n");
281
282 cfg.dev = &pdev->dev;
283 cfg.init_data = config->init_data;
284 cfg.driver_data = drvdata;
285 cfg.of_node = pdev->dev.of_node;
286
287 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
288 &cfg);
289 if (IS_ERR(drvdata->dev)) {
290 ret = PTR_ERR(drvdata->dev);
291 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
292 return ret;
293 }
294
295 platform_set_drvdata(pdev, drvdata);
296
297 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
298 drvdata->desc.fixed_uV);
299
300 return 0;
301}
302
303#if defined(CONFIG_OF)
304static const struct fixed_dev_type fixed_voltage_data = {
305 .has_enable_clock = false,
306};
307
308static const struct fixed_dev_type fixed_clkenable_data = {
309 .has_enable_clock = true,
310};
311
312static const struct fixed_dev_type fixed_domain_data = {
313 .has_performance_state = true,
314};
315
316static const struct of_device_id fixed_of_match[] = {
317 {
318 .compatible = "regulator-fixed",
319 .data = &fixed_voltage_data,
320 },
321 {
322 .compatible = "regulator-fixed-clock",
323 .data = &fixed_clkenable_data,
324 },
325 {
326 .compatible = "regulator-fixed-domain",
327 .data = &fixed_domain_data,
328 },
329 {
330 },
331};
332MODULE_DEVICE_TABLE(of, fixed_of_match);
333#endif
334
335static struct platform_driver regulator_fixed_voltage_driver = {
336 .probe = reg_fixed_voltage_probe,
337 .driver = {
338 .name = "reg-fixed-voltage",
339 .of_match_table = of_match_ptr(fixed_of_match),
340 },
341};
342
343static int __init regulator_fixed_voltage_init(void)
344{
345 return platform_driver_register(®ulator_fixed_voltage_driver);
346}
347subsys_initcall(regulator_fixed_voltage_init);
348
349static void __exit regulator_fixed_voltage_exit(void)
350{
351 platform_driver_unregister(®ulator_fixed_voltage_driver);
352}
353module_exit(regulator_fixed_voltage_exit);
354
355MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
356MODULE_DESCRIPTION("Fixed voltage regulator");
357MODULE_LICENSE("GPL");
358MODULE_ALIAS("platform:reg-fixed-voltage");