4 * Copyright 2008 Wolfson Microelectronics PLC.
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 * Copyright (c) 2009 Nokia Corporation
9 * Roger Quadros <ext-roger.quadros@nokia.com>
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.
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.
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>
30 #include <linux/of_gpio.h>
31 #include <linux/regulator/of_regulator.h>
32 #include <linux/regulator/machine.h>
34 struct fixed_voltage_data
{
35 struct regulator_desc desc
;
36 struct regulator_dev
*dev
;
41 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
42 * @dev: device requesting for fixed_voltage_config
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
48 static struct fixed_voltage_config
*
49 of_get_fixed_voltage_config(struct device
*dev
)
51 struct fixed_voltage_config
*config
;
52 struct device_node
*np
= dev
->of_node
;
53 struct regulator_init_data
*init_data
;
55 config
= devm_kzalloc(dev
, sizeof(struct fixed_voltage_config
),
58 return ERR_PTR(-ENOMEM
);
60 config
->init_data
= of_get_regulator_init_data(dev
, dev
->of_node
);
61 if (!config
->init_data
)
62 return ERR_PTR(-EINVAL
);
64 init_data
= config
->init_data
;
65 init_data
->constraints
.apply_uV
= 0;
67 config
->supply_name
= init_data
->constraints
.name
;
68 if (init_data
->constraints
.min_uV
== init_data
->constraints
.max_uV
) {
69 config
->microvolts
= init_data
->constraints
.min_uV
;
72 "Fixed regulator specified with variable voltages\n");
73 return ERR_PTR(-EINVAL
);
76 if (init_data
->constraints
.boot_on
)
77 config
->enabled_at_boot
= true;
79 config
->gpio
= of_get_named_gpio(np
, "gpio", 0);
81 * of_get_named_gpio() currently returns ENODEV rather than
82 * EPROBE_DEFER. This code attempts to be compatible with both
83 * for now; the ENODEV check can be removed once the API is fixed.
84 * of_get_named_gpio() doesn't differentiate between a missing
85 * property (which would be fine here, since the GPIO is optional)
86 * and some other error. Patches have been posted for both issues.
87 * Once they are check in, we should replace this with:
88 * if (config->gpio < 0 && config->gpio != -ENOENT)
90 if ((config
->gpio
== -ENODEV
) || (config
->gpio
== -EPROBE_DEFER
))
91 return ERR_PTR(-EPROBE_DEFER
);
93 of_property_read_u32(np
, "startup-delay-us", &config
->startup_delay
);
95 config
->enable_high
= of_property_read_bool(np
, "enable-active-high");
96 config
->gpio_is_open_drain
= of_property_read_bool(np
,
99 if (of_find_property(np
, "vin-supply", NULL
))
100 config
->input_supply
= "vin";
105 static struct regulator_ops fixed_voltage_ops
= {
108 static int reg_fixed_voltage_probe(struct platform_device
*pdev
)
110 struct fixed_voltage_config
*config
;
111 struct fixed_voltage_data
*drvdata
;
112 struct regulator_config cfg
= { };
115 if (pdev
->dev
.of_node
) {
116 config
= of_get_fixed_voltage_config(&pdev
->dev
);
118 return PTR_ERR(config
);
120 config
= dev_get_platdata(&pdev
->dev
);
126 drvdata
= devm_kzalloc(&pdev
->dev
, sizeof(struct fixed_voltage_data
),
131 drvdata
->desc
.name
= devm_kstrdup(&pdev
->dev
,
134 if (drvdata
->desc
.name
== NULL
) {
135 dev_err(&pdev
->dev
, "Failed to allocate supply name\n");
138 drvdata
->desc
.type
= REGULATOR_VOLTAGE
;
139 drvdata
->desc
.owner
= THIS_MODULE
;
140 drvdata
->desc
.ops
= &fixed_voltage_ops
;
142 drvdata
->desc
.enable_time
= config
->startup_delay
;
144 if (config
->input_supply
) {
145 drvdata
->desc
.supply_name
= devm_kstrdup(&pdev
->dev
,
146 config
->input_supply
,
148 if (!drvdata
->desc
.supply_name
) {
150 "Failed to allocate input supply\n");
155 if (config
->microvolts
)
156 drvdata
->desc
.n_voltages
= 1;
158 drvdata
->desc
.fixed_uV
= config
->microvolts
;
160 if (config
->gpio
>= 0)
161 cfg
.ena_gpio
= config
->gpio
;
162 cfg
.ena_gpio_invert
= !config
->enable_high
;
163 if (config
->enabled_at_boot
) {
164 if (config
->enable_high
)
165 cfg
.ena_gpio_flags
|= GPIOF_OUT_INIT_HIGH
;
167 cfg
.ena_gpio_flags
|= GPIOF_OUT_INIT_LOW
;
169 if (config
->enable_high
)
170 cfg
.ena_gpio_flags
|= GPIOF_OUT_INIT_LOW
;
172 cfg
.ena_gpio_flags
|= GPIOF_OUT_INIT_HIGH
;
174 if (config
->gpio_is_open_drain
)
175 cfg
.ena_gpio_flags
|= GPIOF_OPEN_DRAIN
;
177 cfg
.dev
= &pdev
->dev
;
178 cfg
.init_data
= config
->init_data
;
179 cfg
.driver_data
= drvdata
;
180 cfg
.of_node
= pdev
->dev
.of_node
;
182 drvdata
->dev
= devm_regulator_register(&pdev
->dev
, &drvdata
->desc
,
184 if (IS_ERR(drvdata
->dev
)) {
185 ret
= PTR_ERR(drvdata
->dev
);
186 dev_err(&pdev
->dev
, "Failed to register regulator: %d\n", ret
);
190 platform_set_drvdata(pdev
, drvdata
);
192 dev_dbg(&pdev
->dev
, "%s supplying %duV\n", drvdata
->desc
.name
,
193 drvdata
->desc
.fixed_uV
);
198 #if defined(CONFIG_OF)
199 static const struct of_device_id fixed_of_match
[] = {
200 { .compatible
= "regulator-fixed", },
203 MODULE_DEVICE_TABLE(of
, fixed_of_match
);
206 static struct platform_driver regulator_fixed_voltage_driver
= {
207 .probe
= reg_fixed_voltage_probe
,
209 .name
= "reg-fixed-voltage",
210 .owner
= THIS_MODULE
,
211 .of_match_table
= of_match_ptr(fixed_of_match
),
215 static int __init
regulator_fixed_voltage_init(void)
217 return platform_driver_register(®ulator_fixed_voltage_driver
);
219 subsys_initcall(regulator_fixed_voltage_init
);
221 static void __exit
regulator_fixed_voltage_exit(void)
223 platform_driver_unregister(®ulator_fixed_voltage_driver
);
225 module_exit(regulator_fixed_voltage_exit
);
227 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
228 MODULE_DESCRIPTION("Fixed voltage regulator");
229 MODULE_LICENSE("GPL");
230 MODULE_ALIAS("platform:reg-fixed-voltage");