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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 * @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 /*
83 * of_get_named_gpio() currently returns ENODEV rather than
84 * EPROBE_DEFER. This code attempts to be compatible with both
85 * for now; the ENODEV check can be removed once the API is fixed.
86 * of_get_named_gpio() doesn't differentiate between a missing
87 * property (which would be fine here, since the GPIO is optional)
88 * and some other error. Patches have been posted for both issues.
89 * Once they are check in, we should replace this with:
90 * if (config->gpio < 0 && config->gpio != -ENOENT)
91 */
92 if ((config->gpio == -ENODEV) || (config->gpio == -EPROBE_DEFER))
93 return ERR_PTR(-EPROBE_DEFER);
94
95 of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
96
97 config->enable_high = of_property_read_bool(np, "enable-active-high");
98 config->gpio_is_open_drain = of_property_read_bool(np,
99 "gpio-open-drain");
100
101 if (of_find_property(np, "vin-supply", NULL))
102 config->input_supply = "vin";
103
104 return config;
105}
106
107static struct regulator_ops fixed_voltage_ops = {
108};
109
110static int reg_fixed_voltage_probe(struct platform_device *pdev)
111{
112 struct fixed_voltage_config *config;
113 struct fixed_voltage_data *drvdata;
114 struct regulator_config cfg = { };
115 int ret;
116
117 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
118 GFP_KERNEL);
119 if (!drvdata)
120 return -ENOMEM;
121
122 if (pdev->dev.of_node) {
123 config = of_get_fixed_voltage_config(&pdev->dev,
124 &drvdata->desc);
125 if (IS_ERR(config))
126 return PTR_ERR(config);
127 } else {
128 config = dev_get_platdata(&pdev->dev);
129 }
130
131 if (!config)
132 return -ENOMEM;
133
134 drvdata->desc.name = devm_kstrdup(&pdev->dev,
135 config->supply_name,
136 GFP_KERNEL);
137 if (drvdata->desc.name == NULL) {
138 dev_err(&pdev->dev, "Failed to allocate supply name\n");
139 return -ENOMEM;
140 }
141 drvdata->desc.type = REGULATOR_VOLTAGE;
142 drvdata->desc.owner = THIS_MODULE;
143 drvdata->desc.ops = &fixed_voltage_ops;
144
145 drvdata->desc.enable_time = config->startup_delay;
146
147 if (config->input_supply) {
148 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
149 config->input_supply,
150 GFP_KERNEL);
151 if (!drvdata->desc.supply_name) {
152 dev_err(&pdev->dev,
153 "Failed to allocate input supply\n");
154 return -ENOMEM;
155 }
156 }
157
158 if (config->microvolts)
159 drvdata->desc.n_voltages = 1;
160
161 drvdata->desc.fixed_uV = config->microvolts;
162
163 if (gpio_is_valid(config->gpio)) {
164 cfg.ena_gpio = config->gpio;
165 if (pdev->dev.of_node)
166 cfg.ena_gpio_initialized = true;
167 }
168 cfg.ena_gpio_invert = !config->enable_high;
169 if (config->enabled_at_boot) {
170 if (config->enable_high)
171 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
172 else
173 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
174 } else {
175 if (config->enable_high)
176 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
177 else
178 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
179 }
180 if (config->gpio_is_open_drain)
181 cfg.ena_gpio_flags |= GPIOF_OPEN_DRAIN;
182
183 cfg.dev = &pdev->dev;
184 cfg.init_data = config->init_data;
185 cfg.driver_data = drvdata;
186 cfg.of_node = pdev->dev.of_node;
187
188 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
189 &cfg);
190 if (IS_ERR(drvdata->dev)) {
191 ret = PTR_ERR(drvdata->dev);
192 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
193 return ret;
194 }
195
196 platform_set_drvdata(pdev, drvdata);
197
198 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
199 drvdata->desc.fixed_uV);
200
201 return 0;
202}
203
204#if defined(CONFIG_OF)
205static const struct of_device_id fixed_of_match[] = {
206 { .compatible = "regulator-fixed", },
207 {},
208};
209MODULE_DEVICE_TABLE(of, fixed_of_match);
210#endif
211
212static struct platform_driver regulator_fixed_voltage_driver = {
213 .probe = reg_fixed_voltage_probe,
214 .driver = {
215 .name = "reg-fixed-voltage",
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/reboot.h>
24#include <linux/regulator/driver.h>
25#include <linux/regulator/fixed.h>
26#include <linux/gpio/consumer.h>
27#include <linux/slab.h>
28#include <linux/of.h>
29#include <linux/regulator/of_regulator.h>
30#include <linux/regulator/machine.h>
31#include <linux/clk.h>
32
33/* Default time in millisecond to wait for emergency shutdown */
34#define FV_DEF_EMERG_SHUTDWN_TMO 10
35
36struct fixed_voltage_data {
37 struct regulator_desc desc;
38 struct regulator_dev *dev;
39
40 struct clk *enable_clock;
41 unsigned int enable_counter;
42 int performance_state;
43};
44
45struct fixed_dev_type {
46 bool has_enable_clock;
47 bool has_performance_state;
48};
49
50static int reg_clock_enable(struct regulator_dev *rdev)
51{
52 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
53 int ret = 0;
54
55 ret = clk_prepare_enable(priv->enable_clock);
56 if (ret)
57 return ret;
58
59 priv->enable_counter++;
60
61 return ret;
62}
63
64static int reg_clock_disable(struct regulator_dev *rdev)
65{
66 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
67
68 clk_disable_unprepare(priv->enable_clock);
69 priv->enable_counter--;
70
71 return 0;
72}
73
74static int reg_domain_enable(struct regulator_dev *rdev)
75{
76 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
77 struct device *dev = rdev->dev.parent;
78 int ret;
79
80 ret = dev_pm_genpd_set_performance_state(dev, priv->performance_state);
81 if (ret)
82 return ret;
83
84 priv->enable_counter++;
85
86 return ret;
87}
88
89static int reg_domain_disable(struct regulator_dev *rdev)
90{
91 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
92 struct device *dev = rdev->dev.parent;
93 int ret;
94
95 ret = dev_pm_genpd_set_performance_state(dev, 0);
96 if (ret)
97 return ret;
98
99 priv->enable_counter--;
100
101 return 0;
102}
103
104static int reg_is_enabled(struct regulator_dev *rdev)
105{
106 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
107
108 return priv->enable_counter > 0;
109}
110
111static irqreturn_t reg_fixed_under_voltage_irq_handler(int irq, void *data)
112{
113 struct fixed_voltage_data *priv = data;
114 struct regulator_dev *rdev = priv->dev;
115
116 regulator_notifier_call_chain(rdev, REGULATOR_EVENT_UNDER_VOLTAGE,
117 NULL);
118
119 return IRQ_HANDLED;
120}
121
122/**
123 * reg_fixed_get_irqs - Get and register the optional IRQ for fixed voltage
124 * regulator.
125 * @dev: Pointer to the device structure.
126 * @priv: Pointer to fixed_voltage_data structure containing private data.
127 *
128 * This function tries to get the IRQ from the device firmware node.
129 * If it's an optional IRQ and not found, it returns 0.
130 * Otherwise, it attempts to request the threaded IRQ.
131 *
132 * Return: 0 on success, or error code on failure.
133 */
134static int reg_fixed_get_irqs(struct device *dev,
135 struct fixed_voltage_data *priv)
136{
137 int ret;
138
139 ret = fwnode_irq_get(dev_fwnode(dev), 0);
140 /* This is optional IRQ. If not found we will get -EINVAL */
141 if (ret == -EINVAL)
142 return 0;
143 if (ret < 0)
144 return dev_err_probe(dev, ret, "Failed to get IRQ\n");
145
146 ret = devm_request_threaded_irq(dev, ret, NULL,
147 reg_fixed_under_voltage_irq_handler,
148 IRQF_ONESHOT, "under-voltage", priv);
149 if (ret)
150 return dev_err_probe(dev, ret, "Failed to request IRQ\n");
151
152 return 0;
153}
154
155/**
156 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
157 * @dev: device requesting for fixed_voltage_config
158 * @desc: regulator description
159 *
160 * Populates fixed_voltage_config structure by extracting data from device
161 * tree node, returns a pointer to the populated structure of NULL if memory
162 * alloc fails.
163 */
164static struct fixed_voltage_config *
165of_get_fixed_voltage_config(struct device *dev,
166 const struct regulator_desc *desc)
167{
168 struct fixed_voltage_config *config;
169 struct device_node *np = dev->of_node;
170 struct regulator_init_data *init_data;
171
172 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
173 GFP_KERNEL);
174 if (!config)
175 return ERR_PTR(-ENOMEM);
176
177 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc);
178 if (!config->init_data)
179 return ERR_PTR(-EINVAL);
180
181 init_data = config->init_data;
182 init_data->constraints.apply_uV = 0;
183
184 config->supply_name = init_data->constraints.name;
185 if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
186 config->microvolts = init_data->constraints.min_uV;
187 } else {
188 dev_err(dev,
189 "Fixed regulator specified with variable voltages\n");
190 return ERR_PTR(-EINVAL);
191 }
192
193 if (init_data->constraints.boot_on)
194 config->enabled_at_boot = true;
195
196 of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
197 of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay);
198
199 if (of_property_present(np, "vin-supply"))
200 config->input_supply = "vin";
201
202 return config;
203}
204
205static const struct regulator_ops fixed_voltage_ops = {
206};
207
208static const struct regulator_ops fixed_voltage_clkenabled_ops = {
209 .enable = reg_clock_enable,
210 .disable = reg_clock_disable,
211 .is_enabled = reg_is_enabled,
212};
213
214static const struct regulator_ops fixed_voltage_domain_ops = {
215 .enable = reg_domain_enable,
216 .disable = reg_domain_disable,
217 .is_enabled = reg_is_enabled,
218};
219
220static int reg_fixed_voltage_probe(struct platform_device *pdev)
221{
222 struct device *dev = &pdev->dev;
223 struct fixed_voltage_config *config;
224 struct fixed_voltage_data *drvdata;
225 const struct fixed_dev_type *drvtype = of_device_get_match_data(dev);
226 struct regulator_config cfg = { };
227 enum gpiod_flags gflags;
228 int ret;
229
230 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
231 GFP_KERNEL);
232 if (!drvdata)
233 return -ENOMEM;
234
235 if (pdev->dev.of_node) {
236 config = of_get_fixed_voltage_config(&pdev->dev,
237 &drvdata->desc);
238 if (IS_ERR(config))
239 return PTR_ERR(config);
240 } else {
241 config = dev_get_platdata(&pdev->dev);
242 }
243
244 if (!config)
245 return -ENOMEM;
246
247 drvdata->desc.name = devm_kstrdup(&pdev->dev,
248 config->supply_name,
249 GFP_KERNEL);
250 if (drvdata->desc.name == NULL) {
251 dev_err(&pdev->dev, "Failed to allocate supply name\n");
252 return -ENOMEM;
253 }
254 drvdata->desc.type = REGULATOR_VOLTAGE;
255 drvdata->desc.owner = THIS_MODULE;
256
257 if (drvtype && drvtype->has_enable_clock) {
258 drvdata->desc.ops = &fixed_voltage_clkenabled_ops;
259
260 drvdata->enable_clock = devm_clk_get(dev, NULL);
261 if (IS_ERR(drvdata->enable_clock)) {
262 dev_err(dev, "Can't get enable-clock from devicetree\n");
263 return PTR_ERR(drvdata->enable_clock);
264 }
265 } else if (drvtype && drvtype->has_performance_state) {
266 drvdata->desc.ops = &fixed_voltage_domain_ops;
267
268 drvdata->performance_state = of_get_required_opp_performance_state(dev->of_node, 0);
269 if (drvdata->performance_state < 0) {
270 dev_err(dev, "Can't get performance state from devicetree\n");
271 return drvdata->performance_state;
272 }
273 } else {
274 drvdata->desc.ops = &fixed_voltage_ops;
275 }
276
277 drvdata->desc.enable_time = config->startup_delay;
278 drvdata->desc.off_on_delay = config->off_on_delay;
279
280 if (config->input_supply) {
281 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
282 config->input_supply,
283 GFP_KERNEL);
284 if (!drvdata->desc.supply_name)
285 return -ENOMEM;
286 }
287
288 if (config->microvolts)
289 drvdata->desc.n_voltages = 1;
290
291 drvdata->desc.fixed_uV = config->microvolts;
292
293 /*
294 * The signal will be inverted by the GPIO core if flagged so in the
295 * descriptor.
296 */
297 if (config->enabled_at_boot)
298 gflags = GPIOD_OUT_HIGH;
299 else
300 gflags = GPIOD_OUT_LOW;
301
302 /*
303 * Some fixed regulators share the enable line between two
304 * regulators which makes it necessary to get a handle on the
305 * same descriptor for two different consumers. This will get
306 * the GPIO descriptor, but only the first call will initialize
307 * it so any flags such as inversion or open drain will only
308 * be set up by the first caller and assumed identical on the
309 * next caller.
310 *
311 * FIXME: find a better way to deal with this.
312 */
313 gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
314
315 /*
316 * Do not use devm* here: the regulator core takes over the
317 * lifecycle management of the GPIO descriptor.
318 */
319 cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags);
320 if (IS_ERR(cfg.ena_gpiod))
321 return dev_err_probe(&pdev->dev, PTR_ERR(cfg.ena_gpiod),
322 "can't get GPIO\n");
323
324 cfg.dev = &pdev->dev;
325 cfg.init_data = config->init_data;
326 cfg.driver_data = drvdata;
327 cfg.of_node = pdev->dev.of_node;
328
329 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
330 &cfg);
331 if (IS_ERR(drvdata->dev)) {
332 ret = dev_err_probe(&pdev->dev, PTR_ERR(drvdata->dev),
333 "Failed to register regulator: %ld\n",
334 PTR_ERR(drvdata->dev));
335 return ret;
336 }
337
338 platform_set_drvdata(pdev, drvdata);
339
340 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
341 drvdata->desc.fixed_uV);
342
343 ret = reg_fixed_get_irqs(dev, drvdata);
344 if (ret)
345 return ret;
346
347 return 0;
348}
349
350#if defined(CONFIG_OF)
351static const struct fixed_dev_type fixed_voltage_data = {
352 .has_enable_clock = false,
353};
354
355static const struct fixed_dev_type fixed_clkenable_data = {
356 .has_enable_clock = true,
357};
358
359static const struct fixed_dev_type fixed_domain_data = {
360 .has_performance_state = true,
361};
362
363static const struct of_device_id fixed_of_match[] = {
364 {
365 .compatible = "regulator-fixed",
366 .data = &fixed_voltage_data,
367 },
368 {
369 .compatible = "regulator-fixed-clock",
370 .data = &fixed_clkenable_data,
371 },
372 {
373 .compatible = "regulator-fixed-domain",
374 .data = &fixed_domain_data,
375 },
376 {
377 },
378};
379MODULE_DEVICE_TABLE(of, fixed_of_match);
380#endif
381
382static struct platform_driver regulator_fixed_voltage_driver = {
383 .probe = reg_fixed_voltage_probe,
384 .driver = {
385 .name = "reg-fixed-voltage",
386 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
387 .of_match_table = of_match_ptr(fixed_of_match),
388 },
389};
390
391static int __init regulator_fixed_voltage_init(void)
392{
393 return platform_driver_register(®ulator_fixed_voltage_driver);
394}
395subsys_initcall(regulator_fixed_voltage_init);
396
397static void __exit regulator_fixed_voltage_exit(void)
398{
399 platform_driver_unregister(®ulator_fixed_voltage_driver);
400}
401module_exit(regulator_fixed_voltage_exit);
402
403MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
404MODULE_DESCRIPTION("Fixed voltage regulator");
405MODULE_LICENSE("GPL");
406MODULE_ALIAS("platform:reg-fixed-voltage");