[mirror_ubuntu-zesty-kernel.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;
};


/**
 * 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;

	if (of_find_property(np, "vin-supply", NULL))
		config->input_supply = "vin";

	return config;
}

static struct regulator_ops fixed_voltage_ops = {
};

static int 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 = dev_get_platdata(&pdev->dev);
	}

	if (!config)
		return -ENOMEM;

	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
			       GFP_KERNEL);
	if (!drvdata)
		return -ENOMEM;

	drvdata->desc.name = devm_kstrdup(&pdev->dev,
					  config->supply_name,
					  GFP_KERNEL);
	if (drvdata->desc.name == NULL) {
		dev_err(&pdev->dev, "Failed to allocate supply name\n");
		return -ENOMEM;
	}
	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->input_supply) {
		drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
					    config->input_supply,
					    GFP_KERNEL);
		if (!drvdata->desc.supply_name) {
			dev_err(&pdev->dev,
				"Failed to allocate input supply\n");
			return -ENOMEM;
		}
	}

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

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

	platform_set_drvdata(pdev, drvdata);

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

	return 0;
}

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

static struct platform_driver regulator_fixed_voltage_driver = {
	.probe		= reg_fixed_voltage_probe,
	.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;
4b74ff65 MB	37	};
4b74ff65 MB	38
cef49102 RN	39
	40	/**
	41	* of_get_fixed_voltage_config - extract fixed_voltage_config structure info
	42	* @dev: device requesting for fixed_voltage_config
	43	*
	44	* Populates fixed_voltage_config structure by extracting data from device
	45	* tree node, returns a pointer to the populated structure of NULL if memory
	46	* alloc fails.
	47	*/
bc91396b AL	48	static struct fixed_voltage_config *
bc91396b AL	49	of_get_fixed_voltage_config(struct device *dev)
cef49102 RN	50	{
	51	struct fixed_voltage_config *config;
	52	struct device_node *np = dev->of_node;
	53	const __be32 *delay;
	54	struct regulator_init_data *init_data;
	55
	56	config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
	57	GFP_KERNEL);
	58	if (!config)
f141822b	59	return ERR_PTR(-ENOMEM);
cef49102	60
d9a861cc	61	config->init_data = of_get_regulator_init_data(dev, dev->of_node);
4b864af1	62	if (!config->init_data)
f141822b	63	return ERR_PTR(-EINVAL);
4b864af1	64
cef49102	65	init_data = config->init_data;
0c437c4a	66	init_data->constraints.apply_uV = 0;
cef49102 RN	67
	68	config->supply_name = init_data->constraints.name;
	69	if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
	70	config->microvolts = init_data->constraints.min_uV;
	71	} else {
	72	dev_err(dev,
	73	"Fixed regulator specified with variable voltages\n");
f141822b	74	return ERR_PTR(-EINVAL);
cef49102 RN	75	}
	76
	77	if (init_data->constraints.boot_on)
	78	config->enabled_at_boot = true;
	79
	80	config->gpio = of_get_named_gpio(np, "gpio", 0);
f141822b SW	81	/*
	82	* of_get_named_gpio() currently returns ENODEV rather than
	83	* EPROBE_DEFER. This code attempts to be compatible with both
	84	* for now; the ENODEV check can be removed once the API is fixed.
	85	* of_get_named_gpio() doesn't differentiate between a missing
	86	* property (which would be fine here, since the GPIO is optional)
	87	* and some other error. Patches have been posted for both issues.
	88	* Once they are check in, we should replace this with:
	89	* if (config->gpio < 0 && config->gpio != -ENOENT)
	90	*/
	91	if ((config->gpio == -ENODEV) \|\| (config->gpio == -EPROBE_DEFER))
	92	return ERR_PTR(-EPROBE_DEFER);
	93
cef49102 RN	94	delay = of_get_property(np, "startup-delay-us", NULL);
	95	if (delay)
	96	config->startup_delay = be32_to_cpu(*delay);
	97
	98	if (of_find_property(np, "enable-active-high", NULL))
	99	config->enable_high = true;
	100
9a50dba5 LD	101	if (of_find_property(np, "gpio-open-drain", NULL))
	102	config->gpio_is_open_drain = true;
	103
6be5bfc3 LD	104	if (of_find_property(np, "vin-supply", NULL))
	105	config->input_supply = "vin";
	106
cef49102 RN	107	return config;
	108	}
	109
9d442061	110	static struct regulator_ops fixed_voltage_ops = {
9d442061 MB	111	};
9d442061 MB	112
a5023574	113	static int reg_fixed_voltage_probe(struct platform_device *pdev)
4b74ff65	114	{
22d881c0	115	struct fixed_voltage_config *config;
4b74ff65	116	struct fixed_voltage_data *drvdata;
c172708d	117	struct regulator_config cfg = { };
4b74ff65 MB	118	int ret;
4b74ff65 MB	119
f141822b	120	if (pdev->dev.of_node) {
cef49102	121	config = of_get_fixed_voltage_config(&pdev->dev);
f141822b SW	122	if (IS_ERR(config))
	123	return PTR_ERR(config);
	124	} else {
dff91d0b	125	config = dev_get_platdata(&pdev->dev);
f141822b	126	}
22d881c0 AL	127
	128	if (!config)
	129	return -ENOMEM;
cef49102	130
c45bb35f MB	131	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
c45bb35f MB	132	GFP_KERNEL);
f1b3f903	133	if (!drvdata)
84d0ffbe	134	return -ENOMEM;
4b74ff65	135
84d0ffbe MB	136	drvdata->desc.name = devm_kstrdup(&pdev->dev,
	137	config->supply_name,
	138	GFP_KERNEL);
4b74ff65	139	if (drvdata->desc.name == NULL) {
c53ad7fe	140	dev_err(&pdev->dev, "Failed to allocate supply name\n");
84d0ffbe	141	return -ENOMEM;
4b74ff65 MB	142	}
	143	drvdata->desc.type = REGULATOR_VOLTAGE;
	144	drvdata->desc.owner = THIS_MODULE;
25a53dfb	145	drvdata->desc.ops = &fixed_voltage_ops;
1c37f8a8	146
3d0f267f MB	147	drvdata->desc.enable_time = config->startup_delay;
3d0f267f MB	148
6be5bfc3	149	if (config->input_supply) {
84d0ffbe MB	150	drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
	151	config->input_supply,
	152	GFP_KERNEL);
6be5bfc3 LD	153	if (!drvdata->desc.supply_name) {
	154	dev_err(&pdev->dev,
	155	"Failed to allocate input supply\n");
84d0ffbe	156	return -ENOMEM;
6be5bfc3 LD	157	}
	158	}
	159
1c37f8a8 SH	160	if (config->microvolts)
1c37f8a8 SH	161	drvdata->desc.n_voltages = 1;
4b74ff65	162
c368e5fc	163	drvdata->desc.fixed_uV = config->microvolts;
9d442061	164
25a53dfb MB	165	if (config->gpio >= 0)
	166	cfg.ena_gpio = config->gpio;
	167	cfg.ena_gpio_invert = !config->enable_high;
	168	if (config->enabled_at_boot) {
609d5f6d	169	if (config->enable_high)
25a53dfb	170	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_HIGH;
609d5f6d	171	else
25a53dfb	172	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_LOW;
86d9884b	173	} else {
609d5f6d	174	if (config->enable_high)
25a53dfb	175	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_LOW;
609d5f6d	176	else
25a53dfb	177	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_HIGH;
86d9884b	178	}
25a53dfb MB	179	if (config->gpio_is_open_drain)
25a53dfb MB	180	cfg.ena_gpio_flags \|= GPIOF_OPEN_DRAIN;
4b74ff65	181
c172708d MB	182	cfg.dev = &pdev->dev;
	183	cfg.init_data = config->init_data;
	184	cfg.driver_data = drvdata;
	185	cfg.of_node = pdev->dev.of_node;
	186
84d0ffbe MB	187	drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
84d0ffbe MB	188	&cfg);
4b74ff65 MB	189	if (IS_ERR(drvdata->dev)) {
4b74ff65 MB	190	ret = PTR_ERR(drvdata->dev);
c53ad7fe	191	dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
84d0ffbe	192	return ret;
4b74ff65 MB	193	}
	194
	195	platform_set_drvdata(pdev, drvdata);
	196
	197	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
c368e5fc	198	drvdata->desc.fixed_uV);
4b74ff65 MB	199
4b74ff65 MB	200	return 0;
4b74ff65 MB	201	}
4b74ff65 MB	202
cef49102	203	#if defined(CONFIG_OF)
3d68dfe3	204	static const struct of_device_id fixed_of_match[] = {
cef49102 RN	205	{ .compatible = "regulator-fixed", },
	206	{},
	207	};
	208	MODULE_DEVICE_TABLE(of, fixed_of_match);
cef49102 RN	209	#endif
cef49102 RN	210
4b74ff65	211	static struct platform_driver regulator_fixed_voltage_driver = {
8ab3343d	212	.probe = reg_fixed_voltage_probe,
4b74ff65 MB	213	.driver = {
4b74ff65 MB	214	.name = "reg-fixed-voltage",
8ab3343d	215	.owner = THIS_MODULE,
abcfaf23	216	.of_match_table = of_match_ptr(fixed_of_match),
4b74ff65 MB	217	},
	218	};
	219
	220	static int __init regulator_fixed_voltage_init(void)
	221	{
	222	return platform_driver_register(&regulator_fixed_voltage_driver);
	223	}
5a1b22be	224	subsys_initcall(regulator_fixed_voltage_init);
4b74ff65 MB	225
	226	static void __exit regulator_fixed_voltage_exit(void)
	227	{
	228	platform_driver_unregister(&regulator_fixed_voltage_driver);
	229	}
	230	module_exit(regulator_fixed_voltage_exit);
	231
	232	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
	233	MODULE_DESCRIPTION("Fixed voltage regulator");
	234	MODULE_LICENSE("GPL");
38c53c89	235	MODULE_ALIAS("platform:reg-fixed-voltage");