1 files changed, 280 insertions, 0 deletions

diff --git a/drivers/power/supply/gpio-charger.c b/drivers/power/supply/gpio-charger.c
new file mode 100644
index 0000000..c5869b1
--- /dev/null
+++ b/drivers/power/supply/gpio-charger.c
@@ -0,0 +1,280 @@
+/*
+ *  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");