--- /dev/null
+/*
+ * 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");
Code Review / kvmfornfv.git / blobdiff