diff options
Diffstat (limited to 'drivers/power/gpio-charger.c')
| -rw-r--r-- | drivers/power/gpio-charger.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/drivers/power/gpio-charger.c b/drivers/power/gpio-charger.c new file mode 100644 index 00000000000..25b88ac1d44 --- /dev/null +++ b/drivers/power/gpio-charger.c @@ -0,0 +1,188 @@ +/* + * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de> + * Driver for chargers which report their online status through a GPIO pin + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + +#include <linux/device.h> +#include <linux/gpio.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/power_supply.h> +#include <linux/slab.h> + +#include <linux/power/gpio-charger.h> + +struct gpio_charger { + const struct gpio_charger_platform_data *pdata; + unsigned int irq; + + struct power_supply charger; +}; + +static irqreturn_t gpio_charger_irq(int irq, void *devid) +{ + struct power_supply *charger = devid; + + power_supply_changed(charger); + + return IRQ_HANDLED; +} + +static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy) +{ + return container_of(psy, struct gpio_charger, charger); +} + +static int gpio_charger_get_property(struct power_supply *psy, + enum power_supply_property psp, union power_supply_propval *val) +{ + struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy); + const struct gpio_charger_platform_data *pdata = gpio_charger->pdata; + + switch (psp) { + case POWER_SUPPLY_PROP_ONLINE: + val->intval = gpio_get_value(pdata->gpio); + val->intval ^= pdata->gpio_active_low; + break; + default: + return -EINVAL; + } + + return 0; +} + +static enum power_supply_property gpio_charger_properties[] = { + POWER_SUPPLY_PROP_ONLINE, +}; + +static int __devinit gpio_charger_probe(struct platform_device *pdev) +{ + const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data; + struct gpio_charger *gpio_charger; + struct power_supply *charger; + int ret; + int irq; + + if (!pdata) { + dev_err(&pdev->dev, "No platform data\n"); + return -EINVAL; + } + + if (!gpio_is_valid(pdata->gpio)) { + dev_err(&pdev->dev, "Invalid gpio pin\n"); + return -EINVAL; + } + + gpio_charger = kzalloc(sizeof(*gpio_charger), GFP_KERNEL); + if (!gpio_charger) { + dev_err(&pdev->dev, "Failed to alloc driver structure\n"); + return -ENOMEM; + } + + charger = &gpio_charger->charger; + + charger->name = pdata->name ? pdata->name : "gpio-charger"; + charger->type = pdata->type; + charger->properties = gpio_charger_properties; + charger->num_properties = ARRAY_SIZE(gpio_charger_properties); + charger->get_property = gpio_charger_get_property; + charger->supplied_to = pdata->supplied_to; + charger->num_supplicants = pdata->num_supplicants; + + ret = gpio_request(pdata->gpio, dev_name(&pdev->dev)); + if (ret) { + dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret); + goto err_free; + } + ret = gpio_direction_input(pdata->gpio); + if (ret) { + dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret); + goto err_gpio_free; + } + + gpio_charger->pdata = pdata; + + ret = power_supply_register(&pdev->dev, charger); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to register power supply: %d\n", + ret); + goto err_gpio_free; + } + + irq = gpio_to_irq(pdata->gpio); + if (irq > 0) { + ret = request_any_context_irq(irq, gpio_charger_irq, + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, + dev_name(&pdev->dev), charger); + if (ret) + dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret); + else + gpio_charger->irq = irq; + } + + platform_set_drvdata(pdev, gpio_charger); + + return 0; + +err_gpio_free: + gpio_free(pdata->gpio); +err_free: + kfree(gpio_charger); + return ret; +} + +static int __devexit gpio_charger_remove(struct platform_device *pdev) +{ + struct gpio_charger *gpio_charger = platform_get_drvdata(pdev); + + if (gpio_charger->irq) + free_irq(gpio_charger->irq, &gpio_charger->charger); + + power_supply_unregister(&gpio_charger->charger); + + gpio_free(gpio_charger->pdata->gpio); + + platform_set_drvdata(pdev, NULL); + kfree(gpio_charger); + + return 0; +} + +static struct platform_driver gpio_charger_driver = { + .probe = gpio_charger_probe, + .remove = __devexit_p(gpio_charger_remove), + .driver = { + .name = "gpio-charger", + .owner = THIS_MODULE, + }, +}; + +static int __init gpio_charger_init(void) +{ + return platform_driver_register(&gpio_charger_driver); +} +module_init(gpio_charger_init); + +static void __exit gpio_charger_exit(void) +{ + platform_driver_unregister(&gpio_charger_driver); +} +module_exit(gpio_charger_exit); + +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:gpio-charger"); |