[deliverable/linux.git] / drivers / regulator / fixed.c

/*
 * fixed.c
 *
 * Copyright 2008 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 *
 * Copyright (c) 2009 Nokia Corporation
 * Roger Quadros <ext-roger.quadros@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This is useful for systems with mixed controllable and
 * non-controllable regulators, as well as for allowing testing on
 * systems with no controllable regulators.
 */

#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/fixed.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/machine.h>

struct fixed_voltage_data {
	struct regulator_desc desc;
	struct regulator_dev *dev;
	int microvolts;
};


/**
 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
 * @dev: device requesting for fixed_voltage_config
 *
 * Populates fixed_voltage_config structure by extracting data from device
 * tree node, returns a pointer to the populated structure of NULL if memory
 * alloc fails.
 */
static struct fixed_voltage_config *
of_get_fixed_voltage_config(struct device *dev)
{
	struct fixed_voltage_config *config;
	struct device_node *np = dev->of_node;
	const __be32 *delay;
	struct regulator_init_data *init_data;

	config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
								 GFP_KERNEL);
	if (!config)
		return ERR_PTR(-ENOMEM);

	config->init_data = of_get_regulator_init_data(dev, dev->of_node);
	if (!config->init_data)
		return ERR_PTR(-EINVAL);

	init_data = config->init_data;
	init_data->constraints.apply_uV = 0;

	config->supply_name = init_data->constraints.name;
	if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
		config->microvolts = init_data->constraints.min_uV;
	} else {
		dev_err(dev,
			 "Fixed regulator specified with variable voltages\n");
		return ERR_PTR(-EINVAL);
	}

	if (init_data->constraints.boot_on)
		config->enabled_at_boot = true;

	config->gpio = of_get_named_gpio(np, "gpio", 0);
	/*
	 * of_get_named_gpio() currently returns ENODEV rather than
	 * EPROBE_DEFER. This code attempts to be compatible with both
	 * for now; the ENODEV check can be removed once the API is fixed.
	 * of_get_named_gpio() doesn't differentiate between a missing
	 * property (which would be fine here, since the GPIO is optional)
	 * and some other error. Patches have been posted for both issues.
	 * Once they are check in, we should replace this with:
	 * if (config->gpio < 0 && config->gpio != -ENOENT)
	 */
	if ((config->gpio == -ENODEV) || (config->gpio == -EPROBE_DEFER))
		return ERR_PTR(-EPROBE_DEFER);

	delay = of_get_property(np, "startup-delay-us", NULL);
	if (delay)
		config->startup_delay = be32_to_cpu(*delay);

	if (of_find_property(np, "enable-active-high", NULL))
		config->enable_high = true;

	if (of_find_property(np, "gpio-open-drain", NULL))
		config->gpio_is_open_drain = true;

	return config;
}

static int fixed_voltage_get_voltage(struct regulator_dev *dev)
{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	if (data->microvolts)
		return data->microvolts;
	else
		return -EINVAL;
}

static int fixed_voltage_list_voltage(struct regulator_dev *dev,
				      unsigned selector)
{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	if (selector != 0)
		return -EINVAL;

	return data->microvolts;
}

static struct regulator_ops fixed_voltage_ops = {
	.get_voltage = fixed_voltage_get_voltage,
	.list_voltage = fixed_voltage_list_voltage,
};

static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
{
	struct fixed_voltage_config *config;
	struct fixed_voltage_data *drvdata;
	struct regulator_config cfg = { };
	int ret;

	if (pdev->dev.of_node) {
		config = of_get_fixed_voltage_config(&pdev->dev);
		if (IS_ERR(config))
			return PTR_ERR(config);
	} else {
		config = pdev->dev.platform_data;
	}

	if (!config)
		return -ENOMEM;

	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
			       GFP_KERNEL);
	if (drvdata == NULL) {
		dev_err(&pdev->dev, "Failed to allocate device data\n");
		ret = -ENOMEM;
		goto err;
	}

	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	if (drvdata->desc.name == NULL) {
		dev_err(&pdev->dev, "Failed to allocate supply name\n");
		ret = -ENOMEM;
		goto err;
	}
	drvdata->desc.type = REGULATOR_VOLTAGE;
	drvdata->desc.owner = THIS_MODULE;
	drvdata->desc.ops = &fixed_voltage_ops;

	drvdata->desc.enable_time = config->startup_delay;

	if (config->microvolts)
		drvdata->desc.n_voltages = 1;

	drvdata->microvolts = config->microvolts;

	if (config->gpio >= 0)
		cfg.ena_gpio = config->gpio;
	cfg.ena_gpio_invert = !config->enable_high;
	if (config->enabled_at_boot) {
		if (config->enable_high) {
			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
		} else {
			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
		}
	} else {
		if (config->enable_high) {
			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
		} else {
			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
		}
	}
	if (config->gpio_is_open_drain)
		cfg.ena_gpio_flags |= GPIOF_OPEN_DRAIN;

	cfg.dev = &pdev->dev;
	cfg.init_data = config->init_data;
	cfg.driver_data = drvdata;
	cfg.of_node = pdev->dev.of_node;

	drvdata->dev = regulator_register(&drvdata->desc, &cfg);
	if (IS_ERR(drvdata->dev)) {
		ret = PTR_ERR(drvdata->dev);
		dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
		goto err_name;
	}

	platform_set_drvdata(pdev, drvdata);

	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
		drvdata->microvolts);

	return 0;

err_name:
	kfree(drvdata->desc.name);
err:
	return ret;
}

static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
{
	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);

	regulator_unregister(drvdata->dev);
	kfree(drvdata->desc.name);

	return 0;
}

#if defined(CONFIG_OF)
static const struct of_device_id fixed_of_match[] __devinitconst = {
	{ .compatible = "regulator-fixed", },
	{},
};
MODULE_DEVICE_TABLE(of, fixed_of_match);
#endif

static struct platform_driver regulator_fixed_voltage_driver = {
	.probe		= reg_fixed_voltage_probe,
	.remove		= __devexit_p(reg_fixed_voltage_remove),
	.driver		= {
		.name		= "reg-fixed-voltage",
		.owner		= THIS_MODULE,
		.of_match_table = of_match_ptr(fixed_of_match),
	},
};

static int __init regulator_fixed_voltage_init(void)
{
	return platform_driver_register(&regulator_fixed_voltage_driver);
}
subsys_initcall(regulator_fixed_voltage_init);

static void __exit regulator_fixed_voltage_exit(void)
{
	platform_driver_unregister(&regulator_fixed_voltage_driver);
}
module_exit(regulator_fixed_voltage_exit);

MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("Fixed voltage regulator");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:reg-fixed-voltage");
Commit	Line	Data
4b74ff65 MB	1	/*
	2	* fixed.c
	3	*
	4	* Copyright 2008 Wolfson Microelectronics PLC.
	5	*
	6	* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
	7	*
86d9884b RQ	8	* Copyright (c) 2009 Nokia Corporation
	9	* Roger Quadros <ext-roger.quadros@nokia.com>
	10	*
4b74ff65 MB	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>
65602c32	23	#include <linux/module.h>
4b74ff65 MB	24	#include <linux/platform_device.h>
	25	#include <linux/regulator/driver.h>
	26	#include <linux/regulator/fixed.h>
86d9884b	27	#include <linux/gpio.h>
5a0e3ad6	28	#include <linux/slab.h>
cef49102 RN	29	#include <linux/of.h>
	30	#include <linux/of_gpio.h>
	31	#include <linux/regulator/of_regulator.h>
	32	#include <linux/regulator/machine.h>
4b74ff65 MB	33
	34	struct fixed_voltage_data {
	35	struct regulator_desc desc;
	36	struct regulator_dev *dev;
	37	int microvolts;
	38	};
	39
cef49102 RN	40
	41	/**
	42	* of_get_fixed_voltage_config - extract fixed_voltage_config structure info
	43	* @dev: device requesting for fixed_voltage_config
	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	*/
bc91396b AL	49	static struct fixed_voltage_config *
bc91396b AL	50	of_get_fixed_voltage_config(struct device *dev)
cef49102 RN	51	{
	52	struct fixed_voltage_config *config;
	53	struct device_node *np = dev->of_node;
	54	const __be32 *delay;
	55	struct regulator_init_data *init_data;
	56
	57	config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
	58	GFP_KERNEL);
	59	if (!config)
f141822b	60	return ERR_PTR(-ENOMEM);
cef49102	61
d9a861cc	62	config->init_data = of_get_regulator_init_data(dev, dev->of_node);
4b864af1	63	if (!config->init_data)
f141822b	64	return ERR_PTR(-EINVAL);
4b864af1	65
cef49102	66	init_data = config->init_data;
0c437c4a	67	init_data->constraints.apply_uV = 0;
cef49102 RN	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");
f141822b	75	return ERR_PTR(-EINVAL);
cef49102 RN	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);
f141822b SW	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
cef49102 RN	95	delay = of_get_property(np, "startup-delay-us", NULL);
	96	if (delay)
	97	config->startup_delay = be32_to_cpu(*delay);
	98
	99	if (of_find_property(np, "enable-active-high", NULL))
	100	config->enable_high = true;
	101
9a50dba5 LD	102	if (of_find_property(np, "gpio-open-drain", NULL))
	103	config->gpio_is_open_drain = true;
	104
cef49102 RN	105	return config;
	106	}
	107
4b74ff65 MB	108	static int fixed_voltage_get_voltage(struct regulator_dev *dev)
	109	{
	110	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	111
aebe4958 MB	112	if (data->microvolts)
	113	return data->microvolts;
	114	else
	115	return -EINVAL;
4b74ff65 MB	116	}
4b74ff65 MB	117
9035cefc MB	118	static int fixed_voltage_list_voltage(struct regulator_dev *dev,
	119	unsigned selector)
	120	{
	121	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	122
	123	if (selector != 0)
	124	return -EINVAL;
	125
	126	return data->microvolts;
	127	}
	128
9d442061 MB	129	static struct regulator_ops fixed_voltage_ops = {
	130	.get_voltage = fixed_voltage_get_voltage,
	131	.list_voltage = fixed_voltage_list_voltage,
	132	};
	133
8ab3343d	134	static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
4b74ff65	135	{
22d881c0	136	struct fixed_voltage_config *config;
4b74ff65	137	struct fixed_voltage_data *drvdata;
c172708d	138	struct regulator_config cfg = { };
4b74ff65 MB	139	int ret;
4b74ff65 MB	140
f141822b	141	if (pdev->dev.of_node) {
cef49102	142	config = of_get_fixed_voltage_config(&pdev->dev);
f141822b SW	143	if (IS_ERR(config))
	144	return PTR_ERR(config);
	145	} else {
22d881c0	146	config = pdev->dev.platform_data;
f141822b	147	}
22d881c0 AL	148
	149	if (!config)
	150	return -ENOMEM;
cef49102	151
c45bb35f MB	152	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
c45bb35f MB	153	GFP_KERNEL);
4b74ff65	154	if (drvdata == NULL) {
c53ad7fe	155	dev_err(&pdev->dev, "Failed to allocate device data\n");
4b74ff65 MB	156	ret = -ENOMEM;
	157	goto err;
	158	}
	159
	160	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	161	if (drvdata->desc.name == NULL) {
c53ad7fe	162	dev_err(&pdev->dev, "Failed to allocate supply name\n");
4b74ff65 MB	163	ret = -ENOMEM;
	164	goto err;
	165	}
	166	drvdata->desc.type = REGULATOR_VOLTAGE;
	167	drvdata->desc.owner = THIS_MODULE;
25a53dfb	168	drvdata->desc.ops = &fixed_voltage_ops;
1c37f8a8	169
3d0f267f MB	170	drvdata->desc.enable_time = config->startup_delay;
3d0f267f MB	171
1c37f8a8 SH	172	if (config->microvolts)
1c37f8a8 SH	173	drvdata->desc.n_voltages = 1;
4b74ff65 MB	174
4b74ff65 MB	175	drvdata->microvolts = config->microvolts;
9d442061	176
25a53dfb MB	177	if (config->gpio >= 0)
	178	cfg.ena_gpio = config->gpio;
	179	cfg.ena_gpio_invert = !config->enable_high;
	180	if (config->enabled_at_boot) {
	181	if (config->enable_high) {
	182	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_HIGH;
	183	} else {
	184	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_LOW;
	185	}
86d9884b	186	} else {
25a53dfb MB	187	if (config->enable_high) {
	188	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_LOW;
	189	} else {
	190	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_HIGH;
	191	}
86d9884b	192	}
25a53dfb MB	193	if (config->gpio_is_open_drain)
25a53dfb MB	194	cfg.ena_gpio_flags \|= GPIOF_OPEN_DRAIN;
4b74ff65	195
c172708d MB	196	cfg.dev = &pdev->dev;
	197	cfg.init_data = config->init_data;
	198	cfg.driver_data = drvdata;
	199	cfg.of_node = pdev->dev.of_node;
	200
	201	drvdata->dev = regulator_register(&drvdata->desc, &cfg);
4b74ff65 MB	202	if (IS_ERR(drvdata->dev)) {
4b74ff65 MB	203	ret = PTR_ERR(drvdata->dev);
c53ad7fe	204	dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
25a53dfb	205	goto err_name;
4b74ff65 MB	206	}
	207
	208	platform_set_drvdata(pdev, drvdata);
	209
	210	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
	211	drvdata->microvolts);
	212
	213	return 0;
	214
	215	err_name:
	216	kfree(drvdata->desc.name);
	217	err:
4b74ff65 MB	218	return ret;
	219	}
	220
8ab3343d	221	static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
4b74ff65 MB	222	{
	223	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
	224
	225	regulator_unregister(drvdata->dev);
80099c70	226	kfree(drvdata->desc.name);
86d9884b	227
4b74ff65 MB	228	return 0;
	229	}
	230
cef49102 RN	231	#if defined(CONFIG_OF)
	232	static const struct of_device_id fixed_of_match[] __devinitconst = {
	233	{ .compatible = "regulator-fixed", },
	234	{},
	235	};
	236	MODULE_DEVICE_TABLE(of, fixed_of_match);
cef49102 RN	237	#endif
cef49102 RN	238
4b74ff65	239	static struct platform_driver regulator_fixed_voltage_driver = {
8ab3343d DT	240	.probe = reg_fixed_voltage_probe,
8ab3343d DT	241	.remove = __devexit_p(reg_fixed_voltage_remove),
4b74ff65 MB	242	.driver = {
4b74ff65 MB	243	.name = "reg-fixed-voltage",
8ab3343d	244	.owner = THIS_MODULE,
abcfaf23	245	.of_match_table = of_match_ptr(fixed_of_match),
4b74ff65 MB	246	},
	247	};
	248
	249	static int __init regulator_fixed_voltage_init(void)
	250	{
	251	return platform_driver_register(&regulator_fixed_voltage_driver);
	252	}
5a1b22be	253	subsys_initcall(regulator_fixed_voltage_init);
4b74ff65 MB	254
	255	static void __exit regulator_fixed_voltage_exit(void)
	256	{
	257	platform_driver_unregister(&regulator_fixed_voltage_driver);
	258	}
	259	module_exit(regulator_fixed_voltage_exit);
	260
	261	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
	262	MODULE_DESCRIPTION("Fixed voltage regulator");
	263	MODULE_LICENSE("GPL");
38c53c89	264	MODULE_ALIAS("platform:reg-fixed-voltage");