mptcp: really cope with fastopen race
[linux-2.6-block.git] / drivers / regulator / fixed.c
CommitLineData
2874c5fd 1// SPDX-License-Identifier: GPL-2.0-or-later
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2/*
3 * fixed.c
4 *
5 * Copyright 2008 Wolfson Microelectronics PLC.
6 *
7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 *
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9 * Copyright (c) 2009 Nokia Corporation
10 * Roger Quadros <ext-roger.quadros@nokia.com>
11 *
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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>
65602c32 19#include <linux/module.h>
4b74ff65 20#include <linux/platform_device.h>
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21#include <linux/pm_domain.h>
22#include <linux/pm_opp.h>
ecb6f1f4 23#include <linux/reboot.h>
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24#include <linux/regulator/driver.h>
25#include <linux/regulator/fixed.h>
efdfeb07 26#include <linux/gpio/consumer.h>
5a0e3ad6 27#include <linux/slab.h>
cef49102 28#include <linux/of.h>
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29#include <linux/regulator/of_regulator.h>
30#include <linux/regulator/machine.h>
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31#include <linux/clk.h>
32
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33/* Default time in millisecond to wait for emergency shutdown */
34#define FV_DEF_EMERG_SHUTDWN_TMO 10
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35
36struct fixed_voltage_data {
37 struct regulator_desc desc;
38 struct regulator_dev *dev;
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39
40 struct clk *enable_clock;
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41 unsigned int enable_counter;
42 int performance_state;
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43};
44
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45struct fixed_dev_type {
46 bool has_enable_clock;
bf3a28cf 47 bool has_performance_state;
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48};
49
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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
bf3a28cf 59 priv->enable_counter++;
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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);
bf3a28cf 69 priv->enable_counter--;
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70
71 return 0;
72}
73
bf3a28cf 74static int reg_domain_enable(struct regulator_dev *rdev)
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75{
76 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
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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;
8959e532 83
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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;
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93 int ret;
94
95 ret = dev_pm_genpd_set_performance_state(dev, 0);
96 if (ret)
97 return ret;
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98
99 priv->enable_counter--;
100
855bfff9 101 return 0;
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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;
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109}
110
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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}
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154
155/**
156 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
157 * @dev: device requesting for fixed_voltage_config
072e78b1 158 * @desc: regulator description
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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 */
bc91396b 164static struct fixed_voltage_config *
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165of_get_fixed_voltage_config(struct device *dev,
166 const struct regulator_desc *desc)
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167{
168 struct fixed_voltage_config *config;
169 struct device_node *np = dev->of_node;
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170 struct regulator_init_data *init_data;
171
172 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
173 GFP_KERNEL);
174 if (!config)
f141822b 175 return ERR_PTR(-ENOMEM);
cef49102 176
072e78b1 177 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc);
4b864af1 178 if (!config->init_data)
f141822b 179 return ERR_PTR(-EINVAL);
4b864af1 180
cef49102 181 init_data = config->init_data;
0c437c4a 182 init_data->constraints.apply_uV = 0;
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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");
f141822b 190 return ERR_PTR(-EINVAL);
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191 }
192
193 if (init_data->constraints.boot_on)
194 config->enabled_at_boot = true;
195
4127f696 196 of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
f7907e57 197 of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay);
cef49102 198
7dda20c9 199 if (of_property_present(np, "vin-supply"))
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200 config->input_supply = "vin";
201
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202 return config;
203}
204
96ee75ff 205static const struct regulator_ops fixed_voltage_ops = {
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206};
207
96ee75ff 208static const struct regulator_ops fixed_voltage_clkenabled_ops = {
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209 .enable = reg_clock_enable,
210 .disable = reg_clock_disable,
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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,
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218};
219
a5023574 220static int reg_fixed_voltage_probe(struct platform_device *pdev)
4b74ff65 221{
8959e532 222 struct device *dev = &pdev->dev;
22d881c0 223 struct fixed_voltage_config *config;
4b74ff65 224 struct fixed_voltage_data *drvdata;
1d6db22f 225 const struct fixed_dev_type *drvtype = of_device_get_match_data(dev);
c172708d 226 struct regulator_config cfg = { };
efdfeb07 227 enum gpiod_flags gflags;
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228 int ret;
229
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230 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
231 GFP_KERNEL);
232 if (!drvdata)
233 return -ENOMEM;
234
f141822b 235 if (pdev->dev.of_node) {
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236 config = of_get_fixed_voltage_config(&pdev->dev,
237 &drvdata->desc);
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238 if (IS_ERR(config))
239 return PTR_ERR(config);
240 } else {
dff91d0b 241 config = dev_get_platdata(&pdev->dev);
f141822b 242 }
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243
244 if (!config)
245 return -ENOMEM;
cef49102 246
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247 drvdata->desc.name = devm_kstrdup(&pdev->dev,
248 config->supply_name,
249 GFP_KERNEL);
4b74ff65 250 if (drvdata->desc.name == NULL) {
c53ad7fe 251 dev_err(&pdev->dev, "Failed to allocate supply name\n");
84d0ffbe 252 return -ENOMEM;
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253 }
254 drvdata->desc.type = REGULATOR_VOLTAGE;
255 drvdata->desc.owner = THIS_MODULE;
8959e532 256
1d6db22f 257 if (drvtype && drvtype->has_enable_clock) {
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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)) {
09dad81e 262 dev_err(dev, "Can't get enable-clock from devicetree\n");
02bcba0b 263 return PTR_ERR(drvdata->enable_clock);
8959e532 264 }
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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 }
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273 } else {
274 drvdata->desc.ops = &fixed_voltage_ops;
275 }
1c37f8a8 276
3d0f267f 277 drvdata->desc.enable_time = config->startup_delay;
f7907e57 278 drvdata->desc.off_on_delay = config->off_on_delay;
3d0f267f 279
6be5bfc3 280 if (config->input_supply) {
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281 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
282 config->input_supply,
283 GFP_KERNEL);
6c315afe 284 if (!drvdata->desc.supply_name)
84d0ffbe 285 return -ENOMEM;
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286 }
287
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288 if (config->microvolts)
289 drvdata->desc.n_voltages = 1;
4b74ff65 290
c368e5fc 291 drvdata->desc.fixed_uV = config->microvolts;
9d442061 292
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293 /*
294 * The signal will be inverted by the GPIO core if flagged so in the
d3f37233 295 * descriptor.
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296 */
297 if (config->enabled_at_boot)
298 gflags = GPIOD_OUT_HIGH;
299 else
300 gflags = GPIOD_OUT_LOW;
efdfeb07 301
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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
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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);
efdfeb07 320 if (IS_ERR(cfg.ena_gpiod))
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321 return dev_err_probe(&pdev->dev, PTR_ERR(cfg.ena_gpiod),
322 "can't get GPIO\n");
4b74ff65 323
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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
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329 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
330 &cfg);
4b74ff65 331 if (IS_ERR(drvdata->dev)) {
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332 ret = dev_err_probe(&pdev->dev, PTR_ERR(drvdata->dev),
333 "Failed to register regulator: %ld\n",
334 PTR_ERR(drvdata->dev));
84d0ffbe 335 return ret;
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336 }
337
338 platform_set_drvdata(pdev, drvdata);
339
340 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
c368e5fc 341 drvdata->desc.fixed_uV);
4b74ff65 342
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343 ret = reg_fixed_get_irqs(dev, drvdata);
344 if (ret)
345 return ret;
346
4b74ff65 347 return 0;
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348}
349
cef49102 350#if defined(CONFIG_OF)
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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
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359static const struct fixed_dev_type fixed_domain_data = {
360 .has_performance_state = true,
361};
362
3d68dfe3 363static const struct of_device_id fixed_of_match[] = {
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364 {
365 .compatible = "regulator-fixed",
366 .data = &fixed_voltage_data,
367 },
368 {
369 .compatible = "regulator-fixed-clock",
370 .data = &fixed_clkenable_data,
371 },
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372 {
373 .compatible = "regulator-fixed-domain",
374 .data = &fixed_domain_data,
375 },
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376 {
377 },
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378};
379MODULE_DEVICE_TABLE(of, fixed_of_match);
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380#endif
381
4b74ff65 382static struct platform_driver regulator_fixed_voltage_driver = {
8ab3343d 383 .probe = reg_fixed_voltage_probe,
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384 .driver = {
385 .name = "reg-fixed-voltage",
259b93b2 386 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
abcfaf23 387 .of_match_table = of_match_ptr(fixed_of_match),
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388 },
389};
390
391static int __init regulator_fixed_voltage_init(void)
392{
393 return platform_driver_register(&regulator_fixed_voltage_driver);
394}
5a1b22be 395subsys_initcall(regulator_fixed_voltage_init);
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396
397static void __exit regulator_fixed_voltage_exit(void)
398{
399 platform_driver_unregister(&regulator_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");
38c53c89 406MODULE_ALIAS("platform:reg-fixed-voltage");