diff options
Diffstat (limited to 'drivers/power/supply/max8903_charger.c')
| -rw-r--r-- | drivers/power/supply/max8903_charger.c | 423 |
1 files changed, 423 insertions, 0 deletions
diff --git a/drivers/power/supply/max8903_charger.c b/drivers/power/supply/max8903_charger.c new file mode 100644 index 000000000..54d50b55f --- /dev/null +++ b/drivers/power/supply/max8903_charger.c @@ -0,0 +1,423 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * max8903_charger.c - Maxim 8903 USB/Adapter Charger Driver + * + * Copyright (C) 2011 Samsung Electronics + * MyungJoo Ham <myungjoo.ham@samsung.com> + */ + +#include <linux/gpio/consumer.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/slab.h> +#include <linux/power_supply.h> +#include <linux/platform_device.h> + +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 <myungjoo.ham@samsung.com>"); +MODULE_ALIAS("platform:max8903-charger"); |