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(&regulator_fixed_voltage_driver);
223}
224subsys_initcall(regulator_fixed_voltage_init);
225
226static void __exit regulator_fixed_voltage_exit(void)
227{
228	platform_driver_unregister(&regulator_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/*
  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	int microvolts;
 38	int gpio;
 39	unsigned startup_delay;
 40	bool enable_high;
 41	bool is_enabled;
 42};
 43
 44
 45/**
 46 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
 47 * @dev: device requesting for fixed_voltage_config
 
 48 *
 49 * Populates fixed_voltage_config structure by extracting data from device
 50 * tree node, returns a pointer to the populated structure of NULL if memory
 51 * alloc fails.
 52 */
 53static struct fixed_voltage_config *
 54of_get_fixed_voltage_config(struct device *dev)
 
 55{
 56	struct fixed_voltage_config *config;
 57	struct device_node *np = dev->of_node;
 58	const __be32 *delay;
 59	struct regulator_init_data *init_data;
 60
 61	config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
 62								 GFP_KERNEL);
 63	if (!config)
 64		return NULL;
 65
 66	config->init_data = of_get_regulator_init_data(dev, dev->of_node);
 67	if (!config->init_data)
 68		return NULL;
 69
 70	init_data = config->init_data;
 71	init_data->constraints.apply_uV = 0;
 72
 73	config->supply_name = init_data->constraints.name;
 74	if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
 75		config->microvolts = init_data->constraints.min_uV;
 76	} else {
 77		dev_err(dev,
 78			 "Fixed regulator specified with variable voltages\n");
 79		return NULL;
 80	}
 81
 82	if (init_data->constraints.boot_on)
 83		config->enabled_at_boot = true;
 84
 85	config->gpio = of_get_named_gpio(np, "gpio", 0);
 86	delay = of_get_property(np, "startup-delay-us", NULL);
 87	if (delay)
 88		config->startup_delay = be32_to_cpu(*delay);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 89
 90	if (of_find_property(np, "enable-active-high", NULL))
 91		config->enable_high = true;
 92
 93	if (of_find_property(np, "gpio-open-drain", NULL))
 94		config->gpio_is_open_drain = true;
 95
 96	return config;
 97}
 98
 99static int fixed_voltage_is_enabled(struct regulator_dev *dev)
100{
101	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
102
103	return data->is_enabled;
104}
105
106static int fixed_voltage_enable(struct regulator_dev *dev)
107{
108	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
109
110	gpio_set_value_cansleep(data->gpio, data->enable_high);
111	data->is_enabled = true;
112
113	return 0;
114}
115
116static int fixed_voltage_disable(struct regulator_dev *dev)
117{
118	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
119
120	gpio_set_value_cansleep(data->gpio, !data->enable_high);
121	data->is_enabled = false;
122
123	return 0;
124}
125
126static int fixed_voltage_enable_time(struct regulator_dev *dev)
127{
128	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
129
130	return data->startup_delay;
131}
132
133static int fixed_voltage_get_voltage(struct regulator_dev *dev)
134{
135	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
136
137	if (data->microvolts)
138		return data->microvolts;
139	else
140		return -EINVAL;
141}
142
143static int fixed_voltage_list_voltage(struct regulator_dev *dev,
144				      unsigned selector)
145{
146	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
147
148	if (selector != 0)
149		return -EINVAL;
150
151	return data->microvolts;
152}
153
154static struct regulator_ops fixed_voltage_gpio_ops = {
155	.is_enabled = fixed_voltage_is_enabled,
156	.enable = fixed_voltage_enable,
157	.disable = fixed_voltage_disable,
158	.enable_time = fixed_voltage_enable_time,
159	.get_voltage = fixed_voltage_get_voltage,
160	.list_voltage = fixed_voltage_list_voltage,
161};
162
163static struct regulator_ops fixed_voltage_ops = {
164	.get_voltage = fixed_voltage_get_voltage,
165	.list_voltage = fixed_voltage_list_voltage,
166};
167
168static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
169{
170	struct fixed_voltage_config *config;
171	struct fixed_voltage_data *drvdata;
172	struct regulator_config cfg = { };
173	int ret;
174
175	if (pdev->dev.of_node)
176		config = of_get_fixed_voltage_config(&pdev->dev);
177	else
178		config = pdev->dev.platform_data;
 
 
 
 
 
 
 
 
 
179
180	if (!config)
181		return -ENOMEM;
182
183	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
184			       GFP_KERNEL);
185	if (drvdata == NULL) {
186		dev_err(&pdev->dev, "Failed to allocate device data\n");
187		ret = -ENOMEM;
188		goto err;
189	}
190
191	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
192	if (drvdata->desc.name == NULL) {
193		dev_err(&pdev->dev, "Failed to allocate supply name\n");
194		ret = -ENOMEM;
195		goto err;
196	}
197	drvdata->desc.type = REGULATOR_VOLTAGE;
198	drvdata->desc.owner = THIS_MODULE;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
199
200	if (config->microvolts)
201		drvdata->desc.n_voltages = 1;
202
203	drvdata->microvolts = config->microvolts;
204	drvdata->gpio = config->gpio;
205	drvdata->startup_delay = config->startup_delay;
206
207	if (gpio_is_valid(config->gpio)) {
208		int gpio_flag;
209		drvdata->enable_high = config->enable_high;
210
211		/* FIXME: Remove below print warning
212		 *
213		 * config->gpio must be set to -EINVAL by platform code if
214		 * GPIO control is not required. However, early adopters
215		 * not requiring GPIO control may forget to initialize
216		 * config->gpio to -EINVAL. This will cause GPIO 0 to be used
217		 * for GPIO control.
218		 *
219		 * This warning will be removed once there are a couple of users
220		 * for this driver.
221		 */
222		if (!config->gpio)
223			dev_warn(&pdev->dev,
224				"using GPIO 0 for regulator enable control\n");
225
226		/*
227		 * set output direction without changing state
228		 * to prevent glitch
229		 */
230		drvdata->is_enabled = config->enabled_at_boot;
231		ret = drvdata->is_enabled ?
232				config->enable_high : !config->enable_high;
233		gpio_flag = ret ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
234
235		if (config->gpio_is_open_drain)
236			gpio_flag |= GPIOF_OPEN_DRAIN;
237
238		ret = gpio_request_one(config->gpio, gpio_flag,
239						config->supply_name);
240		if (ret) {
241			dev_err(&pdev->dev,
242			   "Could not obtain regulator enable GPIO %d: %d\n",
243							config->gpio, ret);
244			goto err_name;
245		}
246
247		drvdata->desc.ops = &fixed_voltage_gpio_ops;
248
249	} else {
250		drvdata->desc.ops = &fixed_voltage_ops;
 
 
 
251	}
 
 
252
253	cfg.dev = &pdev->dev;
254	cfg.init_data = config->init_data;
255	cfg.driver_data = drvdata;
256	cfg.of_node = pdev->dev.of_node;
257
258	drvdata->dev = regulator_register(&drvdata->desc, &cfg);
 
259	if (IS_ERR(drvdata->dev)) {
260		ret = PTR_ERR(drvdata->dev);
261		dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
262		goto err_gpio;
263	}
264
265	platform_set_drvdata(pdev, drvdata);
266
267	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
268		drvdata->microvolts);
269
270	return 0;
271
272err_gpio:
273	if (gpio_is_valid(config->gpio))
274		gpio_free(config->gpio);
275err_name:
276	kfree(drvdata->desc.name);
277err:
278	return ret;
279}
280
281static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
282{
283	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
284
285	regulator_unregister(drvdata->dev);
286	if (gpio_is_valid(drvdata->gpio))
287		gpio_free(drvdata->gpio);
288	kfree(drvdata->desc.name);
289
290	return 0;
291}
292
293#if defined(CONFIG_OF)
294static const struct of_device_id fixed_of_match[] __devinitconst = {
295	{ .compatible = "regulator-fixed", },
296	{},
297};
298MODULE_DEVICE_TABLE(of, fixed_of_match);
299#else
300#define fixed_of_match NULL
301#endif
302
303static struct platform_driver regulator_fixed_voltage_driver = {
304	.probe		= reg_fixed_voltage_probe,
305	.remove		= __devexit_p(reg_fixed_voltage_remove),
306	.driver		= {
307		.name		= "reg-fixed-voltage",
308		.owner		= THIS_MODULE,
309		.of_match_table = fixed_of_match,
310	},
311};
312
313static int __init regulator_fixed_voltage_init(void)
314{
315	return platform_driver_register(&regulator_fixed_voltage_driver);
316}
317subsys_initcall(regulator_fixed_voltage_init);
318
319static void __exit regulator_fixed_voltage_exit(void)
320{
321	platform_driver_unregister(&regulator_fixed_voltage_driver);
322}
323module_exit(regulator_fixed_voltage_exit);
324
325MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
326MODULE_DESCRIPTION("Fixed voltage regulator");
327MODULE_LICENSE("GPL");
328MODULE_ALIAS("platform:reg-fixed-voltage");