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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/module.h>
24#include <linux/platform_device.h>
25#include <linux/regulator/driver.h>
26#include <linux/regulator/fixed.h>
27#include <linux/gpio.h>
28#include <linux/slab.h>
29#include <linux/of.h>
30#include <linux/of_gpio.h>
31#include <linux/regulator/of_regulator.h>
32#include <linux/regulator/machine.h>
33
34struct fixed_voltage_data {
35 struct regulator_desc desc;
36 struct regulator_dev *dev;
37};
38
39
40/**
41 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
42 * @dev: device requesting for fixed_voltage_config
43 *
44 * Populates fixed_voltage_config structure by extracting data from device
45 * tree node, returns a pointer to the populated structure of NULL if memory
46 * alloc fails.
47 */
48static struct fixed_voltage_config *
49of_get_fixed_voltage_config(struct device *dev)
50{
51 struct fixed_voltage_config *config;
52 struct device_node *np = dev->of_node;
53 const __be32 *delay;
54 struct regulator_init_data *init_data;
55
56 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
57 GFP_KERNEL);
58 if (!config)
59 return ERR_PTR(-ENOMEM);
60
61 config->init_data = of_get_regulator_init_data(dev, dev->of_node);
62 if (!config->init_data)
63 return ERR_PTR(-EINVAL);
64
65 init_data = config->init_data;
66 init_data->constraints.apply_uV = 0;
67
68 config->supply_name = init_data->constraints.name;
69 if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
70 config->microvolts = init_data->constraints.min_uV;
71 } else {
72 dev_err(dev,
73 "Fixed regulator specified with variable voltages\n");
74 return ERR_PTR(-EINVAL);
75 }
76
77 if (init_data->constraints.boot_on)
78 config->enabled_at_boot = true;
79
80 config->gpio = of_get_named_gpio(np, "gpio", 0);
81 /*
82 * of_get_named_gpio() currently returns ENODEV rather than
83 * EPROBE_DEFER. This code attempts to be compatible with both
84 * for now; the ENODEV check can be removed once the API is fixed.
85 * of_get_named_gpio() doesn't differentiate between a missing
86 * property (which would be fine here, since the GPIO is optional)
87 * and some other error. Patches have been posted for both issues.
88 * Once they are check in, we should replace this with:
89 * if (config->gpio < 0 && config->gpio != -ENOENT)
90 */
91 if ((config->gpio == -ENODEV) || (config->gpio == -EPROBE_DEFER))
92 return ERR_PTR(-EPROBE_DEFER);
93
94 delay = of_get_property(np, "startup-delay-us", NULL);
95 if (delay)
96 config->startup_delay = be32_to_cpu(*delay);
97
98 if (of_find_property(np, "enable-active-high", NULL))
99 config->enable_high = true;
100
101 if (of_find_property(np, "gpio-open-drain", NULL))
102 config->gpio_is_open_drain = true;
103
104 if (of_find_property(np, "vin-supply", NULL))
105 config->input_supply = "vin";
106
107 return config;
108}
109
110static struct regulator_ops fixed_voltage_ops = {
111};
112
113static int reg_fixed_voltage_probe(struct platform_device *pdev)
114{
115 struct fixed_voltage_config *config;
116 struct fixed_voltage_data *drvdata;
117 struct regulator_config cfg = { };
118 int ret;
119
120 if (pdev->dev.of_node) {
121 config = of_get_fixed_voltage_config(&pdev->dev);
122 if (IS_ERR(config))
123 return PTR_ERR(config);
124 } else {
125 config = dev_get_platdata(&pdev->dev);
126 }
127
128 if (!config)
129 return -ENOMEM;
130
131 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
132 GFP_KERNEL);
133 if (!drvdata)
134 return -ENOMEM;
135
136 drvdata->desc.name = devm_kstrdup(&pdev->dev,
137 config->supply_name,
138 GFP_KERNEL);
139 if (drvdata->desc.name == NULL) {
140 dev_err(&pdev->dev, "Failed to allocate supply name\n");
141 return -ENOMEM;
142 }
143 drvdata->desc.type = REGULATOR_VOLTAGE;
144 drvdata->desc.owner = THIS_MODULE;
145 drvdata->desc.ops = &fixed_voltage_ops;
146
147 drvdata->desc.enable_time = config->startup_delay;
148
149 if (config->input_supply) {
150 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
151 config->input_supply,
152 GFP_KERNEL);
153 if (!drvdata->desc.supply_name) {
154 dev_err(&pdev->dev,
155 "Failed to allocate input supply\n");
156 return -ENOMEM;
157 }
158 }
159
160 if (config->microvolts)
161 drvdata->desc.n_voltages = 1;
162
163 drvdata->desc.fixed_uV = config->microvolts;
164
165 if (config->gpio >= 0)
166 cfg.ena_gpio = config->gpio;
167 cfg.ena_gpio_invert = !config->enable_high;
168 if (config->enabled_at_boot) {
169 if (config->enable_high)
170 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
171 else
172 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
173 } else {
174 if (config->enable_high)
175 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
176 else
177 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
178 }
179 if (config->gpio_is_open_drain)
180 cfg.ena_gpio_flags |= GPIOF_OPEN_DRAIN;
181
182 cfg.dev = &pdev->dev;
183 cfg.init_data = config->init_data;
184 cfg.driver_data = drvdata;
185 cfg.of_node = pdev->dev.of_node;
186
187 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
188 &cfg);
189 if (IS_ERR(drvdata->dev)) {
190 ret = PTR_ERR(drvdata->dev);
191 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
192 return ret;
193 }
194
195 platform_set_drvdata(pdev, drvdata);
196
197 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
198 drvdata->desc.fixed_uV);
199
200 return 0;
201}
202
203#if defined(CONFIG_OF)
204static const struct of_device_id fixed_of_match[] = {
205 { .compatible = "regulator-fixed", },
206 {},
207};
208MODULE_DEVICE_TABLE(of, fixed_of_match);
209#endif
210
211static struct platform_driver regulator_fixed_voltage_driver = {
212 .probe = reg_fixed_voltage_probe,
213 .driver = {
214 .name = "reg-fixed-voltage",
215 .owner = THIS_MODULE,
216 .of_match_table = of_match_ptr(fixed_of_match),
217 },
218};
219
220static int __init regulator_fixed_voltage_init(void)
221{
222 return platform_driver_register(®ulator_fixed_voltage_driver);
223}
224subsys_initcall(regulator_fixed_voltage_init);
225
226static void __exit regulator_fixed_voltage_exit(void)
227{
228 platform_driver_unregister(®ulator_fixed_voltage_driver);
229}
230module_exit(regulator_fixed_voltage_exit);
231
232MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
233MODULE_DESCRIPTION("Fixed voltage regulator");
234MODULE_LICENSE("GPL");
235MODULE_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 return -ENOMEM;
241 }
242
243 if (config->microvolts)
244 drvdata->desc.n_voltages = 1;
245
246 drvdata->desc.fixed_uV = config->microvolts;
247
248 /*
249 * The signal will be inverted by the GPIO core if flagged so in the
250 * descriptor.
251 */
252 if (config->enabled_at_boot)
253 gflags = GPIOD_OUT_HIGH;
254 else
255 gflags = GPIOD_OUT_LOW;
256
257 /*
258 * Some fixed regulators share the enable line between two
259 * regulators which makes it necessary to get a handle on the
260 * same descriptor for two different consumers. This will get
261 * the GPIO descriptor, but only the first call will initialize
262 * it so any flags such as inversion or open drain will only
263 * be set up by the first caller and assumed identical on the
264 * next caller.
265 *
266 * FIXME: find a better way to deal with this.
267 */
268 gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
269
270 /*
271 * Do not use devm* here: the regulator core takes over the
272 * lifecycle management of the GPIO descriptor.
273 */
274 cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags);
275 if (IS_ERR(cfg.ena_gpiod))
276 return dev_err_probe(&pdev->dev, PTR_ERR(cfg.ena_gpiod),
277 "can't get GPIO\n");
278
279 cfg.dev = &pdev->dev;
280 cfg.init_data = config->init_data;
281 cfg.driver_data = drvdata;
282 cfg.of_node = pdev->dev.of_node;
283
284 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
285 &cfg);
286 if (IS_ERR(drvdata->dev)) {
287 ret = dev_err_probe(&pdev->dev, PTR_ERR(drvdata->dev),
288 "Failed to register regulator: %ld\n",
289 PTR_ERR(drvdata->dev));
290 return ret;
291 }
292
293 platform_set_drvdata(pdev, drvdata);
294
295 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
296 drvdata->desc.fixed_uV);
297
298 return 0;
299}
300
301#if defined(CONFIG_OF)
302static const struct fixed_dev_type fixed_voltage_data = {
303 .has_enable_clock = false,
304};
305
306static const struct fixed_dev_type fixed_clkenable_data = {
307 .has_enable_clock = true,
308};
309
310static const struct fixed_dev_type fixed_domain_data = {
311 .has_performance_state = true,
312};
313
314static const struct of_device_id fixed_of_match[] = {
315 {
316 .compatible = "regulator-fixed",
317 .data = &fixed_voltage_data,
318 },
319 {
320 .compatible = "regulator-fixed-clock",
321 .data = &fixed_clkenable_data,
322 },
323 {
324 .compatible = "regulator-fixed-domain",
325 .data = &fixed_domain_data,
326 },
327 {
328 },
329};
330MODULE_DEVICE_TABLE(of, fixed_of_match);
331#endif
332
333static struct platform_driver regulator_fixed_voltage_driver = {
334 .probe = reg_fixed_voltage_probe,
335 .driver = {
336 .name = "reg-fixed-voltage",
337 .of_match_table = of_match_ptr(fixed_of_match),
338 },
339};
340
341static int __init regulator_fixed_voltage_init(void)
342{
343 return platform_driver_register(®ulator_fixed_voltage_driver);
344}
345subsys_initcall(regulator_fixed_voltage_init);
346
347static void __exit regulator_fixed_voltage_exit(void)
348{
349 platform_driver_unregister(®ulator_fixed_voltage_driver);
350}
351module_exit(regulator_fixed_voltage_exit);
352
353MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
354MODULE_DESCRIPTION("Fixed voltage regulator");
355MODULE_LICENSE("GPL");
356MODULE_ALIAS("platform:reg-fixed-voltage");