[GitHub/mt8127/android_kernel_alcatel_ttab.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/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/fixed.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/slab.h>

struct fixed_voltage_data {
	struct regulator_desc desc;
	struct regulator_dev *dev;
	int microvolts;
	int gpio;
	unsigned startup_delay;
	bool enable_high;
	bool is_enabled;
};

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

	return data->is_enabled;
}

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

	if (gpio_is_valid(data->gpio)) {
		gpio_set_value_cansleep(data->gpio, data->enable_high);
		data->is_enabled = true;
	}

	return 0;
}

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

	if (gpio_is_valid(data->gpio)) {
		gpio_set_value_cansleep(data->gpio, !data->enable_high);
		data->is_enabled = false;
	}

	return 0;
}

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

	return data->startup_delay;
}

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

	return data->microvolts;
}

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 = {
	.is_enabled = fixed_voltage_is_enabled,
	.enable = fixed_voltage_enable,
	.disable = fixed_voltage_disable,
	.enable_time = fixed_voltage_enable_time,
	.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 = pdev->dev.platform_data;
	struct fixed_voltage_data *drvdata;
	int ret;

	drvdata = kzalloc(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.n_voltages = 1;

	drvdata->microvolts = config->microvolts;
	drvdata->gpio = config->gpio;
	drvdata->startup_delay = config->startup_delay;

	if (gpio_is_valid(config->gpio)) {
		drvdata->enable_high = config->enable_high;

		/* FIXME: Remove below print warning
		 *
		 * config->gpio must be set to -EINVAL by platform code if
		 * GPIO control is not required. However, early adopters
		 * not requiring GPIO control may forget to initialize
		 * config->gpio to -EINVAL. This will cause GPIO 0 to be used
		 * for GPIO control.
		 *
		 * This warning will be removed once there are a couple of users
		 * for this driver.
		 */
		if (!config->gpio)
			dev_warn(&pdev->dev,
				"using GPIO 0 for regulator enable control\n");

		ret = gpio_request(config->gpio, config->supply_name);
		if (ret) {
			dev_err(&pdev->dev,
			   "Could not obtain regulator enable GPIO %d: %d\n",
							config->gpio, ret);
			goto err_name;
		}

		/* set output direction without changing state
		 * to prevent glitch
		 */
		drvdata->is_enabled = config->enabled_at_boot;
		ret = drvdata->is_enabled ?
				config->enable_high : !config->enable_high;

		ret = gpio_direction_output(config->gpio, ret);
		if (ret) {
			dev_err(&pdev->dev,
			   "Could not configure regulator enable GPIO %d direction: %d\n",
							config->gpio, ret);
			goto err_gpio;
		}

	} else {
		/* Regulator without GPIO control is considered
		 * always enabled
		 */
		drvdata->is_enabled = true;
	}

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

	platform_set_drvdata(pdev, drvdata);

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

	return 0;

err_gpio:
	if (gpio_is_valid(config->gpio))
		gpio_free(config->gpio);
err_name:
	kfree(drvdata->desc.name);
err:
	kfree(drvdata);
	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);
	if (gpio_is_valid(drvdata->gpio))
		gpio_free(drvdata->gpio);
	kfree(drvdata->desc.name);
	kfree(drvdata);

	return 0;
}

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,
	},
};

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>
	23	#include <linux/platform_device.h>
	24	#include <linux/regulator/driver.h>
	25	#include <linux/regulator/fixed.h>
86d9884b	26	#include <linux/gpio.h>
eda79a30	27	#include <linux/delay.h>
5a0e3ad6	28	#include <linux/slab.h>
4b74ff65 MB	29
	30	struct fixed_voltage_data {
	31	struct regulator_desc desc;
	32	struct regulator_dev *dev;
	33	int microvolts;
86d9884b	34	int gpio;
eda79a30	35	unsigned startup_delay;
8ab3343d DT	36	bool enable_high;
8ab3343d DT	37	bool is_enabled;
4b74ff65 MB	38	};
	39
	40	static int fixed_voltage_is_enabled(struct regulator_dev *dev)
	41	{
86d9884b RQ	42	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	43
	44	return data->is_enabled;
4b74ff65 MB	45	}
	46
	47	static int fixed_voltage_enable(struct regulator_dev *dev)
	48	{
86d9884b RQ	49	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	50
	51	if (gpio_is_valid(data->gpio)) {
	52	gpio_set_value_cansleep(data->gpio, data->enable_high);
8ab3343d	53	data->is_enabled = true;
86d9884b RQ	54	}
	55
	56	return 0;
	57	}
	58
	59	static int fixed_voltage_disable(struct regulator_dev *dev)
	60	{
	61	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	62
	63	if (gpio_is_valid(data->gpio)) {
	64	gpio_set_value_cansleep(data->gpio, !data->enable_high);
8ab3343d	65	data->is_enabled = false;
86d9884b RQ	66	}
86d9884b RQ	67
4b74ff65 MB	68	return 0;
	69	}
	70
17133dc8 MB	71	static int fixed_voltage_enable_time(struct regulator_dev *dev)
	72	{
	73	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	74
	75	return data->startup_delay;
	76	}
	77
4b74ff65 MB	78	static int fixed_voltage_get_voltage(struct regulator_dev *dev)
	79	{
	80	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	81
	82	return data->microvolts;
	83	}
	84
9035cefc MB	85	static int fixed_voltage_list_voltage(struct regulator_dev *dev,
	86	unsigned selector)
	87	{
	88	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	89
	90	if (selector != 0)
	91	return -EINVAL;
	92
	93	return data->microvolts;
	94	}
	95
4b74ff65 MB	96	static struct regulator_ops fixed_voltage_ops = {
	97	.is_enabled = fixed_voltage_is_enabled,
	98	.enable = fixed_voltage_enable,
86d9884b	99	.disable = fixed_voltage_disable,
17133dc8	100	.enable_time = fixed_voltage_enable_time,
4b74ff65	101	.get_voltage = fixed_voltage_get_voltage,
9035cefc	102	.list_voltage = fixed_voltage_list_voltage,
4b74ff65 MB	103	};
4b74ff65 MB	104
8ab3343d	105	static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
4b74ff65 MB	106	{
	107	struct fixed_voltage_config *config = pdev->dev.platform_data;
	108	struct fixed_voltage_data *drvdata;
	109	int ret;
	110
	111	drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
	112	if (drvdata == NULL) {
c53ad7fe	113	dev_err(&pdev->dev, "Failed to allocate device data\n");
4b74ff65 MB	114	ret = -ENOMEM;
	115	goto err;
	116	}
	117
	118	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	119	if (drvdata->desc.name == NULL) {
c53ad7fe	120	dev_err(&pdev->dev, "Failed to allocate supply name\n");
4b74ff65 MB	121	ret = -ENOMEM;
	122	goto err;
	123	}
	124	drvdata->desc.type = REGULATOR_VOLTAGE;
	125	drvdata->desc.owner = THIS_MODULE;
9035cefc MB	126	drvdata->desc.ops = &fixed_voltage_ops;
9035cefc MB	127	drvdata->desc.n_voltages = 1;
4b74ff65 MB	128
4b74ff65 MB	129	drvdata->microvolts = config->microvolts;
86d9884b	130	drvdata->gpio = config->gpio;
eda79a30	131	drvdata->startup_delay = config->startup_delay;
86d9884b RQ	132
	133	if (gpio_is_valid(config->gpio)) {
	134	drvdata->enable_high = config->enable_high;
	135
	136	/* FIXME: Remove below print warning
	137	*
	138	* config->gpio must be set to -EINVAL by platform code if
	139	* GPIO control is not required. However, early adopters
	140	* not requiring GPIO control may forget to initialize
	141	* config->gpio to -EINVAL. This will cause GPIO 0 to be used
	142	* for GPIO control.
	143	*
	144	* This warning will be removed once there are a couple of users
	145	* for this driver.
	146	*/
	147	if (!config->gpio)
	148	dev_warn(&pdev->dev,
	149	"using GPIO 0 for regulator enable control\n");
	150
	151	ret = gpio_request(config->gpio, config->supply_name);
	152	if (ret) {
	153	dev_err(&pdev->dev,
	154	"Could not obtain regulator enable GPIO %d: %d\n",
	155	config->gpio, ret);
	156	goto err_name;
	157	}
	158
	159	/* set output direction without changing state
	160	* to prevent glitch
	161	*/
	162	drvdata->is_enabled = config->enabled_at_boot;
	163	ret = drvdata->is_enabled ?
	164	config->enable_high : !config->enable_high;
	165
	166	ret = gpio_direction_output(config->gpio, ret);
	167	if (ret) {
	168	dev_err(&pdev->dev,
	169	"Could not configure regulator enable GPIO %d direction: %d\n",
	170	config->gpio, ret);
	171	goto err_gpio;
	172	}
	173
	174	} else {
	175	/* Regulator without GPIO control is considered
	176	* always enabled
	177	*/
8ab3343d	178	drvdata->is_enabled = true;
86d9884b	179	}
4b74ff65	180
bcf3402c MB	181	drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
bcf3402c MB	182	config->init_data, drvdata);
4b74ff65 MB	183	if (IS_ERR(drvdata->dev)) {
4b74ff65 MB	184	ret = PTR_ERR(drvdata->dev);
c53ad7fe	185	dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
86d9884b	186	goto err_gpio;
4b74ff65 MB	187	}
	188
	189	platform_set_drvdata(pdev, drvdata);
	190
	191	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
	192	drvdata->microvolts);
	193
	194	return 0;
	195
86d9884b RQ	196	err_gpio:
	197	if (gpio_is_valid(config->gpio))
	198	gpio_free(config->gpio);
4b74ff65 MB	199	err_name:
	200	kfree(drvdata->desc.name);
	201	err:
	202	kfree(drvdata);
	203	return ret;
	204	}
	205
8ab3343d	206	static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
4b74ff65 MB	207	{
	208	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
	209
	210	regulator_unregister(drvdata->dev);
86d9884b RQ	211	if (gpio_is_valid(drvdata->gpio))
86d9884b RQ	212	gpio_free(drvdata->gpio);
80099c70 DC	213	kfree(drvdata->desc.name);
80099c70 DC	214	kfree(drvdata);
86d9884b	215
4b74ff65 MB	216	return 0;
	217	}
	218
	219	static struct platform_driver regulator_fixed_voltage_driver = {
8ab3343d DT	220	.probe = reg_fixed_voltage_probe,
8ab3343d DT	221	.remove = __devexit_p(reg_fixed_voltage_remove),
4b74ff65 MB	222	.driver = {
4b74ff65 MB	223	.name = "reg-fixed-voltage",
8ab3343d	224	.owner = THIS_MODULE,
4b74ff65 MB	225	},
	226	};
	227
	228	static int __init regulator_fixed_voltage_init(void)
	229	{
	230	return platform_driver_register(&regulator_fixed_voltage_driver);
	231	}
5a1b22be	232	subsys_initcall(regulator_fixed_voltage_init);
4b74ff65 MB	233
	234	static void __exit regulator_fixed_voltage_exit(void)
	235	{
	236	platform_driver_unregister(&regulator_fixed_voltage_driver);
	237	}
	238	module_exit(regulator_fixed_voltage_exit);
	239
	240	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
	241	MODULE_DESCRIPTION("Fixed voltage regulator");
	242	MODULE_LICENSE("GPL");
38c53c89	243	MODULE_ALIAS("platform:reg-fixed-voltage");