2 * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
3 * Driver for chargers indicating their status through a GPIO pin
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.
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.
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/types.h>
20 #include <linux/device.h>
21 #include <linux/platform_device.h>
22 #include <linux/power_supply.h>
23 #include <linux/interrupt.h>
24 #include <linux/gpio.h>
26 #include <linux/power/gpio-charger.h>
29 const struct gpio_charger_platform_data *pdata;
33 struct power_supply charger;
36 static irqreturn_t gpio_charger_irq(int irq, void *devid)
38 struct power_supply *charger = devid;
39 power_supply_changed(charger);
44 static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
46 return container_of(psy, struct gpio_charger, charger);
49 static int gpio_charger_get_property(struct power_supply *psy,
50 enum power_supply_property psp,
51 union power_supply_propval *val)
53 struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
54 const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
57 case POWER_SUPPLY_PROP_ONLINE:
58 val->intval = gpio_get_value(pdata->gpio);
59 val->intval ^= pdata->gpio_active_low;
68 static enum power_supply_property gpio_charger_properties[] = {
69 POWER_SUPPLY_PROP_ONLINE,
72 static int __devinit gpio_charger_probe(struct platform_device *pdev)
74 const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
75 struct gpio_charger *gpio_charger;
76 struct power_supply *charger;
80 dev_err(&pdev->dev, "No platform data");
84 gpio_charger = kzalloc(sizeof(*gpio_charger), GFP_KERNEL);
86 charger = &gpio_charger->charger;
88 charger->name = pdata->name;
89 charger->type = pdata->type;
90 charger->properties = gpio_charger_properties;
91 charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
92 charger->get_property = gpio_charger_get_property;
93 charger->supplied_to = pdata->batteries;
94 charger->num_supplicants = pdata->num_batteries;
96 if (gpio_is_valid(pdata->gpio)) {
97 ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
99 dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
102 ret = gpio_direction_input(pdata->gpio);
104 dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
108 gpio_charger->irq = gpio_to_irq(pdata->gpio);
109 if (gpio_charger->irq >= 0) {
110 ret = request_irq(gpio_charger->irq, gpio_charger_irq,
111 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
112 dev_name(&pdev->dev), charger);
114 dev_warn(&pdev->dev, "Failed to request online gpio irq: %d\n", ret);
115 gpio_charger->irq = -1;
120 ret = power_supply_register(&pdev->dev, charger);
122 dev_err(&pdev->dev, "Failed to register power supply: %d\n", ret);
126 gpio_charger->pdata = pdata;
127 platform_set_drvdata(pdev, gpio_charger);
132 if (gpio_is_valid(pdata->gpio)) {
133 if (gpio_charger->irq >= 0)
134 free_irq(gpio_charger->irq, charger);
135 gpio_free(pdata->gpio);
141 static int __devexit gpio_charger_remove(struct platform_device *pdev)
143 struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
144 const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
146 power_supply_unregister(&gpio_charger->charger);
148 if (gpio_is_valid(pdata->gpio)) {
149 if (gpio_charger->irq >= 0)
150 free_irq(gpio_charger->irq, &gpio_charger->charger);
151 gpio_free(pdata->gpio);
154 platform_set_drvdata(pdev, NULL);
160 static struct platform_driver gpio_charger_driver = {
161 .probe = gpio_charger_probe,
162 .remove = __devexit_p(gpio_charger_remove),
164 .name = "gpio-charger",
165 .owner = THIS_MODULE,
169 static int __init gpio_charger_init(void)
171 return platform_driver_register(&gpio_charger_driver);
173 module_init(gpio_charger_init);
175 static void gpio_charger_exit(void)
177 platform_driver_unregister(&gpio_charger_driver);
179 module_exit(gpio_charger_exit);
181 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
182 MODULE_DESCRIPTION("Driver for chargers indicating their status through a gpio");
183 MODULE_LICENSE("GPL");
184 MODULE_ALIAS("platform:gpio-charger");