// SPDX-License-Identifier: GPL-2.0-or-later /* * max8903_charger.c - Maxim 8903 USB/Adapter Charger Driver * * Copyright (C) 2011 Samsung Electronics * MyungJoo Ham */ #include #include #include #include #include #include #include #include struct max8903_data { struct device *dev; struct power_supply *psy; struct power_supply_desc psy_desc; /* * GPIOs * chg, flt, dcm and usus are optional. * dok or uok must be present. * If dok is present, cen must be present. */ struct gpio_desc *cen; /* Charger Enable input */ struct gpio_desc *dok; /* DC (Adapter) Power OK output */ struct gpio_desc *uok; /* USB Power OK output */ struct gpio_desc *chg; /* Charger status output */ struct gpio_desc *flt; /* Fault output */ struct gpio_desc *dcm; /* Current-Limit Mode input (1: DC, 2: USB) */ struct gpio_desc *usus; /* USB Suspend Input (1: suspended) */ bool fault; bool usb_in; bool ta_in; }; static enum power_supply_property max8903_charger_props[] = { POWER_SUPPLY_PROP_STATUS, /* Charger status output */ POWER_SUPPLY_PROP_ONLINE, /* External power source */ POWER_SUPPLY_PROP_HEALTH, /* Fault or OK */ }; static int max8903_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) { struct max8903_data *data = power_supply_get_drvdata(psy); switch (psp) { case POWER_SUPPLY_PROP_STATUS: val->intval = POWER_SUPPLY_STATUS_UNKNOWN; if (data->chg) { if (gpiod_get_value(data->chg)) /* CHG asserted */ val->intval = POWER_SUPPLY_STATUS_CHARGING; else if (data->usb_in || data->ta_in) val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; else val->intval = POWER_SUPPLY_STATUS_DISCHARGING; } break; case POWER_SUPPLY_PROP_ONLINE: val->intval = 0; if (data->usb_in || data->ta_in) val->intval = 1; break; case POWER_SUPPLY_PROP_HEALTH: val->intval = POWER_SUPPLY_HEALTH_GOOD; if (data->fault) val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE; break; default: return -EINVAL; } return 0; } static irqreturn_t max8903_dcin(int irq, void *_data) { struct max8903_data *data = _data; bool ta_in; enum power_supply_type old_type; /* * This means the line is asserted. * * The signal is active low, but the inversion is handled in the GPIO * library as the line should be flagged GPIO_ACTIVE_LOW in the device * tree. */ ta_in = gpiod_get_value(data->dok); if (ta_in == data->ta_in) return IRQ_HANDLED; data->ta_in = ta_in; /* Set Current-Limit-Mode 1:DC 0:USB */ if (data->dcm) gpiod_set_value(data->dcm, ta_in); /* Charger Enable / Disable */ if (data->cen) { int val; if (ta_in) /* Certainly enable if DOK is asserted */ val = 1; else if (data->usb_in) /* Enable if the USB charger is enabled */ val = 1; else /* Else default-disable */ val = 0; gpiod_set_value(data->cen, val); } dev_dbg(data->dev, "TA(DC-IN) Charger %s.\n", ta_in ? "Connected" : "Disconnected"); old_type = data->psy_desc.type; if (data->ta_in) data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS; else if (data->usb_in) data->psy_desc.type = POWER_SUPPLY_TYPE_USB; else data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY; if (old_type != data->psy_desc.type) power_supply_changed(data->psy); return IRQ_HANDLED; } static irqreturn_t max8903_usbin(int irq, void *_data) { struct max8903_data *data = _data; bool usb_in; enum power_supply_type old_type; /* * This means the line is asserted. * * The signal is active low, but the inversion is handled in the GPIO * library as the line should be flagged GPIO_ACTIVE_LOW in the device * tree. */ usb_in = gpiod_get_value(data->uok); if (usb_in == data->usb_in) return IRQ_HANDLED; data->usb_in = usb_in; /* Do not touch Current-Limit-Mode */ /* Charger Enable / Disable */ if (data->cen) { int val; if (usb_in) /* Certainly enable if UOK is asserted */ val = 1; else if (data->ta_in) /* Enable if the DC charger is enabled */ val = 1; else /* Else default-disable */ val = 0; gpiod_set_value(data->cen, val); } dev_dbg(data->dev, "USB Charger %s.\n", usb_in ? "Connected" : "Disconnected"); old_type = data->psy_desc.type; if (data->ta_in) data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS; else if (data->usb_in) data->psy_desc.type = POWER_SUPPLY_TYPE_USB; else data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY; if (old_type != data->psy_desc.type) power_supply_changed(data->psy); return IRQ_HANDLED; } static irqreturn_t max8903_fault(int irq, void *_data) { struct max8903_data *data = _data; bool fault; /* * This means the line is asserted. * * The signal is active low, but the inversion is handled in the GPIO * library as the line should be flagged GPIO_ACTIVE_LOW in the device * tree. */ fault = gpiod_get_value(data->flt); if (fault == data->fault) return IRQ_HANDLED; data->fault = fault; if (fault) dev_err(data->dev, "Charger suffers a fault and stops.\n"); else dev_err(data->dev, "Charger recovered from a fault.\n"); return IRQ_HANDLED; } static int max8903_setup_gpios(struct platform_device *pdev) { struct max8903_data *data = platform_get_drvdata(pdev); struct device *dev = &pdev->dev; bool ta_in = false; bool usb_in = false; enum gpiod_flags flags; data->dok = devm_gpiod_get_optional(dev, "dok", GPIOD_IN); if (IS_ERR(data->dok)) return dev_err_probe(dev, PTR_ERR(data->dok), "failed to get DOK GPIO"); if (data->dok) { gpiod_set_consumer_name(data->dok, data->psy_desc.name); /* * The DC OK is pulled up to 1 and goes low when a charger * is plugged in (active low) but in the device tree the * line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted) * here if the DC charger is plugged in. */ ta_in = gpiod_get_value(data->dok); } data->uok = devm_gpiod_get_optional(dev, "uok", GPIOD_IN); if (IS_ERR(data->uok)) return dev_err_probe(dev, PTR_ERR(data->uok), "failed to get UOK GPIO"); if (data->uok) { gpiod_set_consumer_name(data->uok, data->psy_desc.name); /* * The USB OK is pulled up to 1 and goes low when a USB charger * is plugged in (active low) but in the device tree the * line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted) * here if the USB charger is plugged in. */ usb_in = gpiod_get_value(data->uok); } /* Either DC OK or USB OK must be provided */ if (!data->dok && !data->uok) { dev_err(dev, "no valid power source\n"); return -EINVAL; } /* * If either charger is already connected at this point, * assert the CEN line and enable charging from the start. * * The line is active low but also marked with GPIO_ACTIVE_LOW * in the device tree, so when we assert the line with * GPIOD_OUT_HIGH the line will be driven low. */ flags = (ta_in || usb_in) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW; /* * If DC OK is provided, Charger Enable CEN is compulsory * so this is not optional here. */ data->cen = devm_gpiod_get(dev, "cen", flags); if (IS_ERR(data->cen)) return dev_err_probe(dev, PTR_ERR(data->cen), "failed to get CEN GPIO"); gpiod_set_consumer_name(data->cen, data->psy_desc.name); /* * If the DC charger is connected, then select it. * * The DCM line should be marked GPIO_ACTIVE_HIGH in the * device tree. Driving it high will enable the DC charger * input over the USB charger input. */ flags = ta_in ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW; data->dcm = devm_gpiod_get_optional(dev, "dcm", flags); if (IS_ERR(data->dcm)) return dev_err_probe(dev, PTR_ERR(data->dcm), "failed to get DCM GPIO"); gpiod_set_consumer_name(data->dcm, data->psy_desc.name); data->chg = devm_gpiod_get_optional(dev, "chg", GPIOD_IN); if (IS_ERR(data->chg)) return dev_err_probe(dev, PTR_ERR(data->chg), "failed to get CHG GPIO"); gpiod_set_consumer_name(data->chg, data->psy_desc.name); data->flt = devm_gpiod_get_optional(dev, "flt", GPIOD_IN); if (IS_ERR(data->flt)) return dev_err_probe(dev, PTR_ERR(data->flt), "failed to get FLT GPIO"); gpiod_set_consumer_name(data->flt, data->psy_desc.name); data->usus = devm_gpiod_get_optional(dev, "usus", GPIOD_IN); if (IS_ERR(data->usus)) return dev_err_probe(dev, PTR_ERR(data->usus), "failed to get USUS GPIO"); gpiod_set_consumer_name(data->usus, data->psy_desc.name); data->fault = false; data->ta_in = ta_in; data->usb_in = usb_in; return 0; } static int max8903_probe(struct platform_device *pdev) { struct max8903_data *data; struct device *dev = &pdev->dev; struct power_supply_config psy_cfg = {}; int ret = 0; data = devm_kzalloc(dev, sizeof(struct max8903_data), GFP_KERNEL); if (!data) return -ENOMEM; data->dev = dev; platform_set_drvdata(pdev, data); ret = max8903_setup_gpios(pdev); if (ret) return ret; data->psy_desc.name = "max8903_charger"; data->psy_desc.type = (data->ta_in) ? POWER_SUPPLY_TYPE_MAINS : ((data->usb_in) ? POWER_SUPPLY_TYPE_USB : POWER_SUPPLY_TYPE_BATTERY); data->psy_desc.get_property = max8903_get_property; data->psy_desc.properties = max8903_charger_props; data->psy_desc.num_properties = ARRAY_SIZE(max8903_charger_props); psy_cfg.of_node = dev->of_node; psy_cfg.drv_data = data; data->psy = devm_power_supply_register(dev, &data->psy_desc, &psy_cfg); if (IS_ERR(data->psy)) { dev_err(dev, "failed: power supply register.\n"); return PTR_ERR(data->psy); } if (data->dok) { ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->dok), NULL, max8903_dcin, IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING | IRQF_ONESHOT, "MAX8903 DC IN", data); if (ret) { dev_err(dev, "Cannot request irq %d for DC (%d)\n", gpiod_to_irq(data->dok), ret); return ret; } } if (data->uok) { ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->uok), NULL, max8903_usbin, IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING | IRQF_ONESHOT, "MAX8903 USB IN", data); if (ret) { dev_err(dev, "Cannot request irq %d for USB (%d)\n", gpiod_to_irq(data->uok), ret); return ret; } } if (data->flt) { ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->flt), NULL, max8903_fault, IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING | IRQF_ONESHOT, "MAX8903 Fault", data); if (ret) { dev_err(dev, "Cannot request irq %d for Fault (%d)\n", gpiod_to_irq(data->flt), ret); return ret; } } return 0; } static const struct of_device_id max8903_match_ids[] = { { .compatible = "maxim,max8903", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, max8903_match_ids); static struct platform_driver max8903_driver = { .probe = max8903_probe, .driver = { .name = "max8903-charger", .of_match_table = max8903_match_ids }, }; module_platform_driver(max8903_driver); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("MAX8903 Charger Driver"); MODULE_AUTHOR("MyungJoo Ham "); MODULE_ALIAS("platform:max8903-charger");