summaryrefslogtreecommitdiffstats
path: root/drivers/regulator/fixed.c
blob: 47e9043a3a4f6c0a1858a24c1acbad16f39a370a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
/*
 * 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;
	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);

	of_property_read_u32(np, "startup-delay-us", &config->startup_delay);

	config->enable_high = of_property_read_bool(np, "enable-active-high");
	config->gpio_is_open_drain = of_property_read_bool(np,
							   "gpio-open-drain");

	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",
		.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");
OpenPOWER on IntegriCloud