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(&regulator_fixed_voltage_driver);
289}
290subsys_initcall(regulator_fixed_voltage_init);
291
292static void __exit regulator_fixed_voltage_exit(void)
293{
294	platform_driver_unregister(&regulator_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// 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
127	if (of_find_property(np, "vin-supply", NULL))
128		config->input_supply = "vin";
129
130	return config;
131}
132
133static struct regulator_ops fixed_voltage_ops = {
134};
135
136static struct regulator_ops fixed_voltage_clkenabled_ops = {
137	.enable = reg_clock_enable,
138	.disable = reg_clock_disable,
139	.is_enabled = reg_clock_is_enabled,
140};
141
142static int reg_fixed_voltage_probe(struct platform_device *pdev)
143{
144	struct device *dev = &pdev->dev;
145	struct fixed_voltage_config *config;
146	struct fixed_voltage_data *drvdata;
147	const struct fixed_dev_type *drvtype = of_device_get_match_data(dev);
148	struct regulator_config cfg = { };
149	enum gpiod_flags gflags;
150	int ret;
151
152	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
153			       GFP_KERNEL);
154	if (!drvdata)
155		return -ENOMEM;
156
157	if (pdev->dev.of_node) {
158		config = of_get_fixed_voltage_config(&pdev->dev,
159						     &drvdata->desc);
160		if (IS_ERR(config))
161			return PTR_ERR(config);
162	} else {
163		config = dev_get_platdata(&pdev->dev);
164	}
165
166	if (!config)
167		return -ENOMEM;
168
169	drvdata->desc.name = devm_kstrdup(&pdev->dev,
170					  config->supply_name,
171					  GFP_KERNEL);
172	if (drvdata->desc.name == NULL) {
173		dev_err(&pdev->dev, "Failed to allocate supply name\n");
174		return -ENOMEM;
175	}
176	drvdata->desc.type = REGULATOR_VOLTAGE;
177	drvdata->desc.owner = THIS_MODULE;
178
179	if (drvtype && drvtype->has_enable_clock) {
180		drvdata->desc.ops = &fixed_voltage_clkenabled_ops;
181
182		drvdata->enable_clock = devm_clk_get(dev, NULL);
183		if (IS_ERR(drvdata->enable_clock)) {
184			dev_err(dev, "Cant get enable-clock from devicetree\n");
185			return -ENOENT;
186		}
187	} else {
188		drvdata->desc.ops = &fixed_voltage_ops;
189	}
190
191	drvdata->desc.enable_time = config->startup_delay;
 
192
193	if (config->input_supply) {
194		drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
195					    config->input_supply,
196					    GFP_KERNEL);
197		if (!drvdata->desc.supply_name) {
198			dev_err(&pdev->dev,
199				"Failed to allocate input supply\n");
200			return -ENOMEM;
201		}
202	}
203
204	if (config->microvolts)
205		drvdata->desc.n_voltages = 1;
206
207	drvdata->desc.fixed_uV = config->microvolts;
208
209	/*
210	 * The signal will be inverted by the GPIO core if flagged so in the
211	 * decriptor.
212	 */
213	if (config->enabled_at_boot)
214		gflags = GPIOD_OUT_HIGH;
215	else
216		gflags = GPIOD_OUT_LOW;
217
218	/*
219	 * Some fixed regulators share the enable line between two
220	 * regulators which makes it necessary to get a handle on the
221	 * same descriptor for two different consumers. This will get
222	 * the GPIO descriptor, but only the first call will initialize
223	 * it so any flags such as inversion or open drain will only
224	 * be set up by the first caller and assumed identical on the
225	 * next caller.
226	 *
227	 * FIXME: find a better way to deal with this.
228	 */
229	gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
230
231	/*
232	 * Do not use devm* here: the regulator core takes over the
233	 * lifecycle management of the GPIO descriptor.
234	 */
235	cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags);
236	if (IS_ERR(cfg.ena_gpiod))
237		return PTR_ERR(cfg.ena_gpiod);
238
239	cfg.dev = &pdev->dev;
240	cfg.init_data = config->init_data;
241	cfg.driver_data = drvdata;
242	cfg.of_node = pdev->dev.of_node;
243
244	drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
245					       &cfg);
246	if (IS_ERR(drvdata->dev)) {
247		ret = PTR_ERR(drvdata->dev);
248		dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
249		return ret;
250	}
251
252	platform_set_drvdata(pdev, drvdata);
253
254	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
255		drvdata->desc.fixed_uV);
256
257	return 0;
258}
259
260#if defined(CONFIG_OF)
261static const struct of_device_id fixed_of_match[] = {
262	{
263		.compatible = "regulator-fixed",
264		.data = &fixed_voltage_data,
265	},
266	{
267		.compatible = "regulator-fixed-clock",
268		.data = &fixed_clkenable_data,
269	},
270	{
271	},
272};
273MODULE_DEVICE_TABLE(of, fixed_of_match);
274#endif
275
276static struct platform_driver regulator_fixed_voltage_driver = {
277	.probe		= reg_fixed_voltage_probe,
278	.driver		= {
279		.name		= "reg-fixed-voltage",
280		.of_match_table = of_match_ptr(fixed_of_match),
281	},
282};
283
284static int __init regulator_fixed_voltage_init(void)
285{
286	return platform_driver_register(&regulator_fixed_voltage_driver);
287}
288subsys_initcall(regulator_fixed_voltage_init);
289
290static void __exit regulator_fixed_voltage_exit(void)
291{
292	platform_driver_unregister(&regulator_fixed_voltage_driver);
293}
294module_exit(regulator_fixed_voltage_exit);
295
296MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
297MODULE_DESCRIPTION("Fixed voltage regulator");
298MODULE_LICENSE("GPL");
299MODULE_ALIAS("platform:reg-fixed-voltage");