drivers/power/gpio-charger.c - kernel/bruno - Git at Google

 /*
  *  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/of.h>
 #include <linux/of_gpio.h>

 #include <linux/power/gpio-charger.h>

 struct gpio_charger {
 	const struct gpio_charger_platform_data *pdata;
 	unsigned int irq;
 	bool wakeup_enabled;

 	struct power_supply *charger;
 	struct power_supply_desc charger_desc;
 };

 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 power_supply_get_drvdata(psy);
 }

 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_cansleep(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
 struct gpio_charger_platform_data *gpio_charger_parse_dt(struct device *dev)
 {
 	struct device_node *np = dev->of_node;
 	struct gpio_charger_platform_data *pdata;
 	const char *chargetype;
 	enum of_gpio_flags flags;
 	int ret;

 	if (!np)
 		return ERR_PTR(-ENOENT);

 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return ERR_PTR(-ENOMEM);

 	pdata->name = np->name;

 	pdata->gpio = of_get_gpio_flags(np, 0, &flags);
 	if (pdata->gpio < 0) {
 		if (pdata->gpio != -EPROBE_DEFER)
 			dev_err(dev, "could not get charger gpio\n");
 		return ERR_PTR(pdata->gpio);
 	}

 	pdata->gpio_active_low = !!(flags & OF_GPIO_ACTIVE_LOW);

 	pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
 	ret = of_property_read_string(np, "charger-type", &chargetype);
 	if (ret >= 0) {
 		if (!strncmp("unknown", chargetype, 7))
 			pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
 		else if (!strncmp("battery", chargetype, 7))
 			pdata->type = POWER_SUPPLY_TYPE_BATTERY;
 		else if (!strncmp("ups", chargetype, 3))
 			pdata->type = POWER_SUPPLY_TYPE_UPS;
 		else if (!strncmp("mains", chargetype, 5))
 			pdata->type = POWER_SUPPLY_TYPE_MAINS;
 		else if (!strncmp("usb-sdp", chargetype, 7))
 			pdata->type = POWER_SUPPLY_TYPE_USB;
 		else if (!strncmp("usb-dcp", chargetype, 7))
 			pdata->type = POWER_SUPPLY_TYPE_USB_DCP;
 		else if (!strncmp("usb-cdp", chargetype, 7))
 			pdata->type = POWER_SUPPLY_TYPE_USB_CDP;
 		else if (!strncmp("usb-aca", chargetype, 7))
 			pdata->type = POWER_SUPPLY_TYPE_USB_ACA;
 		else
 			dev_warn(dev, "unknown charger type %s\n", chargetype);
 	}

 	return pdata;
 }

 static int gpio_charger_probe(struct platform_device *pdev)
 {
 	const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
 	struct power_supply_config psy_cfg = {};
 	struct gpio_charger *gpio_charger;
 	struct power_supply_desc *charger_desc;
 	int ret;
 	int irq;

 	if (!pdata) {
 		pdata = gpio_charger_parse_dt(&pdev->dev);
 		if (IS_ERR(pdata)) {
 			ret = PTR_ERR(pdata);
 			if (ret != -EPROBE_DEFER)
 				dev_err(&pdev->dev, "No platform data\n");
 			return ret;
 		}
 	}

 	if (!gpio_is_valid(pdata->gpio)) {
 		dev_err(&pdev->dev, "Invalid gpio pin\n");
 		return -EINVAL;
 	}

 	gpio_charger = devm_kzalloc(&pdev->dev, sizeof(*gpio_charger),
 					GFP_KERNEL);
 	if (!gpio_charger) {
 		dev_err(&pdev->dev, "Failed to alloc driver structure\n");
 		return -ENOMEM;
 	}

 	charger_desc = &gpio_charger->charger_desc;

 	charger_desc->name = pdata->name ? pdata->name : "gpio-charger";
 	charger_desc->type = pdata->type;
 	charger_desc->properties = gpio_charger_properties;
 	charger_desc->num_properties = ARRAY_SIZE(gpio_charger_properties);
 	charger_desc->get_property = gpio_charger_get_property;

 	psy_cfg.supplied_to = pdata->supplied_to;
 	psy_cfg.num_supplicants = pdata->num_supplicants;
 	psy_cfg.of_node = pdev->dev.of_node;
 	psy_cfg.drv_data = gpio_charger;

 	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;

 	gpio_charger->charger = power_supply_register(&pdev->dev,
 						      charger_desc, &psy_cfg);
 	if (IS_ERR(gpio_charger->charger)) {
 		ret = PTR_ERR(gpio_charger->charger);
 		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), gpio_charger->charger);
 		if (ret < 0)
 			dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
 		else
 			gpio_charger->irq = irq;
 	}

 	platform_set_drvdata(pdev, gpio_charger);

 	device_init_wakeup(&pdev->dev, 1);

 	return 0;

 err_gpio_free:
 	gpio_free(pdata->gpio);
 err_free:
 	return ret;
 }

 static int 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);

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int gpio_charger_suspend(struct device *dev)
 {
 	struct gpio_charger *gpio_charger = dev_get_drvdata(dev);

 	if (device_may_wakeup(dev))
 		gpio_charger->wakeup_enabled =
 			!enable_irq_wake(gpio_charger->irq);

 	return 0;
 }

 static int gpio_charger_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);

 	if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
 		disable_irq_wake(gpio_charger->irq);
 	power_supply_changed(gpio_charger->charger);

 	return 0;
 }
 #endif

 static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
 		gpio_charger_suspend, gpio_charger_resume);

 static const struct of_device_id gpio_charger_match[] = {
 	{ .compatible = "gpio-charger" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, gpio_charger_match);

 static struct platform_driver gpio_charger_driver = {
 	.probe = gpio_charger_probe,
 	.remove = gpio_charger_remove,
 	.driver = {
 		.name = "gpio-charger",
 		.pm = &gpio_charger_pm_ops,
 		.of_match_table = gpio_charger_match,
 	},
 };

 module_platform_driver(gpio_charger_driver);

 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");
	/*
	* 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/of.h>
	#include <linux/of_gpio.h>

	#include <linux/power/gpio-charger.h>

	struct gpio_charger {
	const struct gpio_charger_platform_data *pdata;
	unsigned int irq;
	bool wakeup_enabled;

	struct power_supply *charger;
	struct power_supply_desc charger_desc;
	};

	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 power_supply_get_drvdata(psy);
	}

	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_cansleep(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
	struct gpio_charger_platform_data gpio_charger_parse_dt(struct device dev)
	{
	struct device_node *np = dev->of_node;
	struct gpio_charger_platform_data *pdata;
	const char *chargetype;
	enum of_gpio_flags flags;
	int ret;

	if (!np)
	return ERR_PTR(-ENOENT);

	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
	return ERR_PTR(-ENOMEM);

	pdata->name = np->name;

	pdata->gpio = of_get_gpio_flags(np, 0, &flags);
	if (pdata->gpio < 0) {
	if (pdata->gpio != -EPROBE_DEFER)
	dev_err(dev, "could not get charger gpio\n");
	return ERR_PTR(pdata->gpio);
	}

	pdata->gpio_active_low = !!(flags & OF_GPIO_ACTIVE_LOW);

	pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
	ret = of_property_read_string(np, "charger-type", &chargetype);
	if (ret >= 0) {
	if (!strncmp("unknown", chargetype, 7))
	pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
	else if (!strncmp("battery", chargetype, 7))
	pdata->type = POWER_SUPPLY_TYPE_BATTERY;
	else if (!strncmp("ups", chargetype, 3))
	pdata->type = POWER_SUPPLY_TYPE_UPS;
	else if (!strncmp("mains", chargetype, 5))
	pdata->type = POWER_SUPPLY_TYPE_MAINS;
	else if (!strncmp("usb-sdp", chargetype, 7))
	pdata->type = POWER_SUPPLY_TYPE_USB;
	else if (!strncmp("usb-dcp", chargetype, 7))
	pdata->type = POWER_SUPPLY_TYPE_USB_DCP;
	else if (!strncmp("usb-cdp", chargetype, 7))
	pdata->type = POWER_SUPPLY_TYPE_USB_CDP;
	else if (!strncmp("usb-aca", chargetype, 7))
	pdata->type = POWER_SUPPLY_TYPE_USB_ACA;
	else
	dev_warn(dev, "unknown charger type %s\n", chargetype);
	}

	return pdata;
	}

	static int gpio_charger_probe(struct platform_device *pdev)
	{
	const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
	struct power_supply_config psy_cfg = {};
	struct gpio_charger *gpio_charger;
	struct power_supply_desc *charger_desc;
	int ret;
	int irq;

	if (!pdata) {
	pdata = gpio_charger_parse_dt(&pdev->dev);
	if (IS_ERR(pdata)) {
	ret = PTR_ERR(pdata);
	if (ret != -EPROBE_DEFER)
	dev_err(&pdev->dev, "No platform data\n");
	return ret;
	}
	}

	if (!gpio_is_valid(pdata->gpio)) {
	dev_err(&pdev->dev, "Invalid gpio pin\n");
	return -EINVAL;
	}

	gpio_charger = devm_kzalloc(&pdev->dev, sizeof(*gpio_charger),
	GFP_KERNEL);
	if (!gpio_charger) {
	dev_err(&pdev->dev, "Failed to alloc driver structure\n");
	return -ENOMEM;
	}

	charger_desc = &gpio_charger->charger_desc;

	charger_desc->name = pdata->name ? pdata->name : "gpio-charger";
	charger_desc->type = pdata->type;
	charger_desc->properties = gpio_charger_properties;
	charger_desc->num_properties = ARRAY_SIZE(gpio_charger_properties);
	charger_desc->get_property = gpio_charger_get_property;

	psy_cfg.supplied_to = pdata->supplied_to;
	psy_cfg.num_supplicants = pdata->num_supplicants;
	psy_cfg.of_node = pdev->dev.of_node;
	psy_cfg.drv_data = gpio_charger;

	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;

	gpio_charger->charger = power_supply_register(&pdev->dev,
	charger_desc, &psy_cfg);
	if (IS_ERR(gpio_charger->charger)) {
	ret = PTR_ERR(gpio_charger->charger);
	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), gpio_charger->charger);
	if (ret < 0)
	dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
	else
	gpio_charger->irq = irq;
	}

	platform_set_drvdata(pdev, gpio_charger);

	device_init_wakeup(&pdev->dev, 1);

	return 0;

	err_gpio_free:
	gpio_free(pdata->gpio);
	err_free:
	return ret;
	}

	static int 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);

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int gpio_charger_suspend(struct device *dev)
	{
	struct gpio_charger *gpio_charger = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
	gpio_charger->wakeup_enabled =
	!enable_irq_wake(gpio_charger->irq);

	return 0;
	}

	static int gpio_charger_resume(struct device *dev)
	{
	struct platform_device *pdev = to_platform_device(dev);
	struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);

	if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
	disable_irq_wake(gpio_charger->irq);
	power_supply_changed(gpio_charger->charger);

	return 0;
	}
	#endif

	static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
	gpio_charger_suspend, gpio_charger_resume);

	static const struct of_device_id gpio_charger_match[] = {
	{ .compatible = "gpio-charger" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, gpio_charger_match);

	static struct platform_driver gpio_charger_driver = {
	.probe = gpio_charger_probe,
	.remove = gpio_charger_remove,
	.driver = {
	.name = "gpio-charger",
	.pm = &gpio_charger_pm_ops,
	.of_match_table = gpio_charger_match,
	},
	};

	module_platform_driver(gpio_charger_driver);

	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");