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1/*
2 * fixed.c
3 *
4 * Copyright 2008 Wolfson Microelectronics PLC.
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * Copyright (c) 2009 Nokia Corporation
9 * Roger Quadros <ext-roger.quadros@nokia.com>
10 *
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>
26#include <linux/gpio.h>
27#include <linux/delay.h>
28#include <linux/slab.h>
29
30struct fixed_voltage_data {
31 struct regulator_desc desc;
32 struct regulator_dev *dev;
33 int microvolts;
34 int gpio;
35 unsigned startup_delay;
36 bool enable_high;
37 bool is_enabled;
38};
39
40static int fixed_voltage_is_enabled(struct regulator_dev *dev)
41{
42 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
43
44 return data->is_enabled;
45}
46
47static int fixed_voltage_enable(struct regulator_dev *dev)
48{
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);
53 data->is_enabled = true;
54 }
55
56 return 0;
57}
58
59static 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);
65 data->is_enabled = false;
66 }
67
68 return 0;
69}
70
71static 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
78static 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
85static 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
96static struct regulator_ops fixed_voltage_ops = {
97 .is_enabled = fixed_voltage_is_enabled,
98 .enable = fixed_voltage_enable,
99 .disable = fixed_voltage_disable,
100 .enable_time = fixed_voltage_enable_time,
101 .get_voltage = fixed_voltage_get_voltage,
102 .list_voltage = fixed_voltage_list_voltage,
103};
104
105static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
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) {
113 dev_err(&pdev->dev, "Failed to allocate device data\n");
114 ret = -ENOMEM;
115 goto err;
116 }
117
118 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
119 if (drvdata->desc.name == NULL) {
120 dev_err(&pdev->dev, "Failed to allocate supply name\n");
121 ret = -ENOMEM;
122 goto err;
123 }
124 drvdata->desc.type = REGULATOR_VOLTAGE;
125 drvdata->desc.owner = THIS_MODULE;
126 drvdata->desc.ops = &fixed_voltage_ops;
127 drvdata->desc.n_voltages = 1;
128
129 drvdata->microvolts = config->microvolts;
130 drvdata->gpio = config->gpio;
131 drvdata->startup_delay = config->startup_delay;
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 */
178 drvdata->is_enabled = true;
179 }
180
181 drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
182 config->init_data, drvdata);
183 if (IS_ERR(drvdata->dev)) {
184 ret = PTR_ERR(drvdata->dev);
185 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
186 goto err_gpio;
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
196err_gpio:
197 if (gpio_is_valid(config->gpio))
198 gpio_free(config->gpio);
199err_name:
200 kfree(drvdata->desc.name);
201err:
202 kfree(drvdata);
203 return ret;
204}
205
206static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
207{
208 struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
209
210 regulator_unregister(drvdata->dev);
211 if (gpio_is_valid(drvdata->gpio))
212 gpio_free(drvdata->gpio);
213 kfree(drvdata->desc.name);
214 kfree(drvdata);
215
216 return 0;
217}
218
219static struct platform_driver regulator_fixed_voltage_driver = {
220 .probe = reg_fixed_voltage_probe,
221 .remove = __devexit_p(reg_fixed_voltage_remove),
222 .driver = {
223 .name = "reg-fixed-voltage",
224 .owner = THIS_MODULE,
225 },
226};
227
228static int __init regulator_fixed_voltage_init(void)
229{
230 return platform_driver_register(®ulator_fixed_voltage_driver);
231}
232subsys_initcall(regulator_fixed_voltage_init);
233
234static void __exit regulator_fixed_voltage_exit(void)
235{
236 platform_driver_unregister(®ulator_fixed_voltage_driver);
237}
238module_exit(regulator_fixed_voltage_exit);
239
240MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
241MODULE_DESCRIPTION("Fixed voltage regulator");
242MODULE_LICENSE("GPL");
243MODULE_ALIAS("platform:reg-fixed-voltage");
1/*
2 * fixed.c
3 *
4 * Copyright 2008 Wolfson Microelectronics PLC.
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * Copyright (c) 2009 Nokia Corporation
9 * Roger Quadros <ext-roger.quadros@nokia.com>
10 *
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/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>
29#include <linux/of.h>
30#include <linux/of_gpio.h>
31#include <linux/regulator/of_regulator.h>
32#include <linux/regulator/machine.h>
33
34struct fixed_voltage_data {
35 struct regulator_desc desc;
36 struct regulator_dev *dev;
37};
38
39
40/**
41 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
42 * @dev: device requesting for fixed_voltage_config
43 * @desc: regulator description
44 *
45 * Populates fixed_voltage_config structure by extracting data from device
46 * tree node, returns a pointer to the populated structure of NULL if memory
47 * alloc fails.
48 */
49static struct fixed_voltage_config *
50of_get_fixed_voltage_config(struct device *dev,
51 const struct regulator_desc *desc)
52{
53 struct fixed_voltage_config *config;
54 struct device_node *np = dev->of_node;
55 struct regulator_init_data *init_data;
56
57 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
58 GFP_KERNEL);
59 if (!config)
60 return ERR_PTR(-ENOMEM);
61
62 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc);
63 if (!config->init_data)
64 return ERR_PTR(-EINVAL);
65
66 init_data = config->init_data;
67 init_data->constraints.apply_uV = 0;
68
69 config->supply_name = init_data->constraints.name;
70 if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
71 config->microvolts = init_data->constraints.min_uV;
72 } else {
73 dev_err(dev,
74 "Fixed regulator specified with variable voltages\n");
75 return ERR_PTR(-EINVAL);
76 }
77
78 if (init_data->constraints.boot_on)
79 config->enabled_at_boot = true;
80
81 config->gpio = of_get_named_gpio(np, "gpio", 0);
82 /*
83 * of_get_named_gpio() currently returns ENODEV rather than
84 * EPROBE_DEFER. This code attempts to be compatible with both
85 * for now; the ENODEV check can be removed once the API is fixed.
86 * of_get_named_gpio() doesn't differentiate between a missing
87 * property (which would be fine here, since the GPIO is optional)
88 * and some other error. Patches have been posted for both issues.
89 * Once they are check in, we should replace this with:
90 * if (config->gpio < 0 && config->gpio != -ENOENT)
91 */
92 if ((config->gpio == -ENODEV) || (config->gpio == -EPROBE_DEFER))
93 return ERR_PTR(-EPROBE_DEFER);
94
95 of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
96
97 config->enable_high = of_property_read_bool(np, "enable-active-high");
98 config->gpio_is_open_drain = of_property_read_bool(np,
99 "gpio-open-drain");
100
101 if (of_find_property(np, "vin-supply", NULL))
102 config->input_supply = "vin";
103
104 return config;
105}
106
107static struct regulator_ops fixed_voltage_ops = {
108};
109
110static int reg_fixed_voltage_probe(struct platform_device *pdev)
111{
112 struct fixed_voltage_config *config;
113 struct fixed_voltage_data *drvdata;
114 struct regulator_config cfg = { };
115 int ret;
116
117 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
118 GFP_KERNEL);
119 if (!drvdata)
120 return -ENOMEM;
121
122 if (pdev->dev.of_node) {
123 config = of_get_fixed_voltage_config(&pdev->dev,
124 &drvdata->desc);
125 if (IS_ERR(config))
126 return PTR_ERR(config);
127 } else {
128 config = dev_get_platdata(&pdev->dev);
129 }
130
131 if (!config)
132 return -ENOMEM;
133
134 drvdata->desc.name = devm_kstrdup(&pdev->dev,
135 config->supply_name,
136 GFP_KERNEL);
137 if (drvdata->desc.name == NULL) {
138 dev_err(&pdev->dev, "Failed to allocate supply name\n");
139 return -ENOMEM;
140 }
141 drvdata->desc.type = REGULATOR_VOLTAGE;
142 drvdata->desc.owner = THIS_MODULE;
143 drvdata->desc.ops = &fixed_voltage_ops;
144
145 drvdata->desc.enable_time = config->startup_delay;
146
147 if (config->input_supply) {
148 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
149 config->input_supply,
150 GFP_KERNEL);
151 if (!drvdata->desc.supply_name) {
152 dev_err(&pdev->dev,
153 "Failed to allocate input supply\n");
154 return -ENOMEM;
155 }
156 }
157
158 if (config->microvolts)
159 drvdata->desc.n_voltages = 1;
160
161 drvdata->desc.fixed_uV = config->microvolts;
162
163 if (gpio_is_valid(config->gpio)) {
164 cfg.ena_gpio = config->gpio;
165 if (pdev->dev.of_node)
166 cfg.ena_gpio_initialized = true;
167 }
168 cfg.ena_gpio_invert = !config->enable_high;
169 if (config->enabled_at_boot) {
170 if (config->enable_high)
171 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
172 else
173 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
174 } else {
175 if (config->enable_high)
176 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
177 else
178 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
179 }
180 if (config->gpio_is_open_drain)
181 cfg.ena_gpio_flags |= GPIOF_OPEN_DRAIN;
182
183 cfg.dev = &pdev->dev;
184 cfg.init_data = config->init_data;
185 cfg.driver_data = drvdata;
186 cfg.of_node = pdev->dev.of_node;
187
188 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
189 &cfg);
190 if (IS_ERR(drvdata->dev)) {
191 ret = PTR_ERR(drvdata->dev);
192 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
193 return ret;
194 }
195
196 platform_set_drvdata(pdev, drvdata);
197
198 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
199 drvdata->desc.fixed_uV);
200
201 return 0;
202}
203
204#if defined(CONFIG_OF)
205static const struct of_device_id fixed_of_match[] = {
206 { .compatible = "regulator-fixed", },
207 {},
208};
209MODULE_DEVICE_TABLE(of, fixed_of_match);
210#endif
211
212static struct platform_driver regulator_fixed_voltage_driver = {
213 .probe = reg_fixed_voltage_probe,
214 .driver = {
215 .name = "reg-fixed-voltage",
216 .of_match_table = of_match_ptr(fixed_of_match),
217 },
218};
219
220static int __init regulator_fixed_voltage_init(void)
221{
222 return platform_driver_register(®ulator_fixed_voltage_driver);
223}
224subsys_initcall(regulator_fixed_voltage_init);
225
226static void __exit regulator_fixed_voltage_exit(void)
227{
228 platform_driver_unregister(®ulator_fixed_voltage_driver);
229}
230module_exit(regulator_fixed_voltage_exit);
231
232MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
233MODULE_DESCRIPTION("Fixed voltage regulator");
234MODULE_LICENSE("GPL");
235MODULE_ALIAS("platform:reg-fixed-voltage");