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path: root/drivers/power/gpio-charger.c
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-rw-r--r--drivers/power/gpio-charger.c185
1 files changed, 185 insertions, 0 deletions
diff --git a/drivers/power/gpio-charger.c b/drivers/power/gpio-charger.c
new file mode 100644
index 000000000000..fccbe99b619c
--- /dev/null
+++ b/drivers/power/gpio-charger.c
@@ -0,0 +1,185 @@
1/*
2 * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
3 * Driver for chargers which report their online status through a GPIO pin
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 *
10 * You should have received a copy of the GNU General Public License along
11 * with this program; if not, write to the Free Software Foundation, Inc.,
12 * 675 Mass Ave, Cambridge, MA 02139, USA.
13 *
14 */
15
16#include <linux/device.h>
17#include <linux/gpio.h>
18#include <linux/init.h>
19#include <linux/interrupt.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/platform_device.h>
23#include <linux/power_supply.h>
24#include <linux/slab.h>
25
26#include <linux/power/gpio-charger.h>
27
28struct gpio_charger {
29 const struct gpio_charger_platform_data *pdata;
30 unsigned int irq;
31
32 struct power_supply charger;
33};
34
35static irqreturn_t gpio_charger_irq(int irq, void *devid)
36{
37 struct power_supply *charger = devid;
38
39 power_supply_changed(charger);
40
41 return IRQ_HANDLED;
42}
43
44static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
45{
46 return container_of(psy, struct gpio_charger, charger);
47}
48
49static int gpio_charger_get_property(struct power_supply *psy,
50 enum power_supply_property psp, union power_supply_propval *val)
51{
52 struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
53 const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
54
55 switch (psp) {
56 case POWER_SUPPLY_PROP_ONLINE:
57 val->intval = gpio_get_value(pdata->gpio);
58 val->intval ^= pdata->gpio_active_low;
59 break;
60 default:
61 return -EINVAL;
62 }
63
64 return 0;
65}
66
67static enum power_supply_property gpio_charger_properties[] = {
68 POWER_SUPPLY_PROP_ONLINE,
69};
70
71static int __devinit gpio_charger_probe(struct platform_device *pdev)
72{
73 const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
74 struct gpio_charger *gpio_charger;
75 struct power_supply *charger;
76 int ret;
77 int irq;
78
79 if (!pdata) {
80 dev_err(&pdev->dev, "No platform data\n");
81 return -EINVAL;
82 }
83
84 if (!gpio_is_valid(pdata->gpio)) {
85 dev_err(&pdev->dev, "Invalid gpio pin\n");
86 return -EINVAL;
87 }
88
89 gpio_charger = kzalloc(sizeof(*gpio_charger), GFP_KERNEL);
90
91 charger = &gpio_charger->charger;
92
93 charger->name = pdata->name;
94 charger->type = pdata->type;
95 charger->properties = gpio_charger_properties;
96 charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
97 charger->get_property = gpio_charger_get_property;
98 charger->supplied_to = pdata->supplied_to;
99 charger->num_supplicants = pdata->num_supplicants;
100
101 ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
102 if (ret) {
103 dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
104 goto err_free;
105 }
106 ret = gpio_direction_input(pdata->gpio);
107 if (ret) {
108 dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
109 goto err_gpio_free;
110 }
111
112 irq = gpio_to_irq(pdata->gpio);
113 if (irq > 0) {
114 ret = request_irq(irq, gpio_charger_irq,
115 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
116 dev_name(&pdev->dev), charger);
117 if (ret)
118 dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
119 else
120 gpio_charger->irq = irq;
121 }
122
123 gpio_charger->pdata = pdata;
124
125 ret = power_supply_register(&pdev->dev, charger);
126 if (ret < 0) {
127 dev_err(&pdev->dev, "Failed to register power supply: %d\n", ret);
128 goto err_irq_free;
129 }
130
131 platform_set_drvdata(pdev, gpio_charger);
132
133 return 0;
134
135err_irq_free:
136 if (gpio_charger->irq)
137 free_irq(gpio_charger->irq, charger);
138err_gpio_free:
139 gpio_free(pdata->gpio);
140err_free:
141 kfree(gpio_charger);
142 return ret;
143}
144
145static int __devexit gpio_charger_remove(struct platform_device *pdev)
146{
147 struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
148
149 power_supply_unregister(&gpio_charger->charger);
150
151 if (gpio_charger->irq)
152 free_irq(gpio_charger->irq, &gpio_charger->charger);
153 gpio_free(gpio_charger->pdata->gpio);
154
155 platform_set_drvdata(pdev, NULL);
156 kfree(gpio_charger);
157
158 return 0;
159}
160
161static struct platform_driver gpio_charger_driver = {
162 .probe = gpio_charger_probe,
163 .remove = __devexit_p(gpio_charger_remove),
164 .driver = {
165 .name = "gpio-charger",
166 .owner = THIS_MODULE,
167 },
168};
169
170static int __init gpio_charger_init(void)
171{
172 return platform_driver_register(&gpio_charger_driver);
173}
174module_init(gpio_charger_init);
175
176static void __exit gpio_charger_exit(void)
177{
178 platform_driver_unregister(&gpio_charger_driver);
179}
180module_exit(gpio_charger_exit);
181
182MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
183MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
184MODULE_LICENSE("GPL");
185MODULE_ALIAS("platform:gpio-charger");