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
;
54 struct regulator_init_data
*init_data
;
56 config
= devm_kzalloc(dev
, sizeof(struct fixed_voltage_config
),
59 return ERR_PTR(-ENOMEM
);
61 config
->init_data
= of_get_regulator_init_data(dev
, dev
->of_node
);
62 if (!config
->init_data
)
63 return ERR_PTR(-EINVAL
);
65 init_data
= config
->init_data
;
66 init_data
->constraints
.apply_uV
= 0;
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
;
73 "Fixed regulator specified with variable voltages\n");
74 return ERR_PTR(-EINVAL
);
77 if (init_data
->constraints
.boot_on
)
78 config
->enabled_at_boot
= true;
80 config
->gpio
= of_get_named_gpio(np
, "gpio", 0);
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)
91 if ((config
->gpio
== -ENODEV
) || (config
->gpio
== -EPROBE_DEFER
))
92 return ERR_PTR(-EPROBE_DEFER
);
94 delay
= of_get_property(np
, "startup-delay-us", NULL
);
96 config
->startup_delay
= be32_to_cpu(*delay
);
98 if (of_find_property(np
, "enable-active-high", NULL
))
99 config
->enable_high
= true;
101 if (of_find_property(np
, "gpio-open-drain", NULL
))
102 config
->gpio_is_open_drain
= true;
104 if (of_find_property(np
, "vin-supply", NULL
))
105 config
->input_supply
= "vin";
110 static struct regulator_ops fixed_voltage_ops
= {
113 static int reg_fixed_voltage_probe(struct platform_device
*pdev
)
115 struct fixed_voltage_config
*config
;
116 struct fixed_voltage_data
*drvdata
;
117 struct regulator_config cfg
= { };
120 if (pdev
->dev
.of_node
) {
121 config
= of_get_fixed_voltage_config(&pdev
->dev
);
123 return PTR_ERR(config
);
125 config
= dev_get_platdata(&pdev
->dev
);
131 drvdata
= devm_kzalloc(&pdev
->dev
, sizeof(struct fixed_voltage_data
),
136 drvdata
->desc
.name
= devm_kstrdup(&pdev
->dev
,
139 if (drvdata
->desc
.name
== NULL
) {
140 dev_err(&pdev
->dev
, "Failed to allocate supply name\n");
143 drvdata
->desc
.type
= REGULATOR_VOLTAGE
;
144 drvdata
->desc
.owner
= THIS_MODULE
;
145 drvdata
->desc
.ops
= &fixed_voltage_ops
;
147 drvdata
->desc
.enable_time
= config
->startup_delay
;
149 if (config
->input_supply
) {
150 drvdata
->desc
.supply_name
= devm_kstrdup(&pdev
->dev
,
151 config
->input_supply
,
153 if (!drvdata
->desc
.supply_name
) {
155 "Failed to allocate input supply\n");
160 if (config
->microvolts
)
161 drvdata
->desc
.n_voltages
= 1;
163 drvdata
->desc
.fixed_uV
= config
->microvolts
;
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
) {
169 if (config
->enable_high
)
170 cfg
.ena_gpio_flags
|= GPIOF_OUT_INIT_HIGH
;
172 cfg
.ena_gpio_flags
|= GPIOF_OUT_INIT_LOW
;
174 if (config
->enable_high
)
175 cfg
.ena_gpio_flags
|= GPIOF_OUT_INIT_LOW
;
177 cfg
.ena_gpio_flags
|= GPIOF_OUT_INIT_HIGH
;
179 if (config
->gpio_is_open_drain
)
180 cfg
.ena_gpio_flags
|= GPIOF_OPEN_DRAIN
;
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
;
187 drvdata
->dev
= devm_regulator_register(&pdev
->dev
, &drvdata
->desc
,
189 if (IS_ERR(drvdata
->dev
)) {
190 ret
= PTR_ERR(drvdata
->dev
);
191 dev_err(&pdev
->dev
, "Failed to register regulator: %d\n", ret
);
195 platform_set_drvdata(pdev
, drvdata
);
197 dev_dbg(&pdev
->dev
, "%s supplying %duV\n", drvdata
->desc
.name
,
198 drvdata
->desc
.fixed_uV
);
203 #if defined(CONFIG_OF)
204 static const struct of_device_id fixed_of_match
[] = {
205 { .compatible
= "regulator-fixed", },
208 MODULE_DEVICE_TABLE(of
, fixed_of_match
);
211 static struct platform_driver regulator_fixed_voltage_driver
= {
212 .probe
= reg_fixed_voltage_probe
,
214 .name
= "reg-fixed-voltage",
215 .owner
= THIS_MODULE
,
216 .of_match_table
= of_match_ptr(fixed_of_match
),
220 static int __init
regulator_fixed_voltage_init(void)
222 return platform_driver_register(®ulator_fixed_voltage_driver
);
224 subsys_initcall(regulator_fixed_voltage_init
);
226 static void __exit
regulator_fixed_voltage_exit(void)
228 platform_driver_unregister(®ulator_fixed_voltage_driver
);
230 module_exit(regulator_fixed_voltage_exit
);
232 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
233 MODULE_DESCRIPTION("Fixed voltage regulator");
234 MODULE_LICENSE("GPL");
235 MODULE_ALIAS("platform:reg-fixed-voltage");