/* * Copyright (C) 2010, Lars-Peter Clausen * 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 #include /* For legacy platform data */ #include #include #include #include #include #include #include #include #include #include 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; struct gpio_desc *gpiod; }; 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 = gpiod_get_value_cansleep(gpio_charger->gpiod); /* This xor is only ever used with legacy 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; 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->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; } } 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; } /* * This will fetch a GPIO descriptor from device tree, ACPI or * boardfile descriptor tables. It's good to try this first. */ gpio_charger->gpiod = devm_gpiod_get(&pdev->dev, NULL, GPIOD_IN); /* * If this fails and we're not using device tree, try the * legacy platform data method. */ if (IS_ERR(gpio_charger->gpiod) && !pdev->dev.of_node) { /* Non-DT: use legacy GPIO numbers */ if (!gpio_is_valid(pdata->gpio)) { dev_err(&pdev->dev, "Invalid gpio pin in pdata\n"); return -EINVAL; } ret = devm_gpio_request_one(&pdev->dev, pdata->gpio, GPIOF_IN, dev_name(&pdev->dev)); if (ret) { dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret); return ret; } /* Then convert this to gpiod for now */ gpio_charger->gpiod = gpio_to_desc(pdata->gpio); } else if (IS_ERR(gpio_charger->gpiod)) { /* Just try again if this happens */ if (PTR_ERR(gpio_charger->gpiod) == -EPROBE_DEFER) return -EPROBE_DEFER; dev_err(&pdev->dev, "error getting GPIO descriptor\n"); return PTR_ERR(gpio_charger->gpiod); } 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; gpio_charger->charger = devm_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); return ret; } irq = gpiod_to_irq(gpio_charger->gpiod); if (irq > 0) { ret = devm_request_any_context_irq(&pdev->dev, 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; } #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, .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 "); MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:gpio-charger");