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