| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de> |
| * Driver for chargers which report their online status through a GPIO pin |
| */ |
| |
| #include <linux/device.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/gpio/consumer.h> |
| |
| #include <linux/power/gpio-charger.h> |
| |
| struct gpio_mapping { |
| u32 limit_ua; |
| u32 gpiodata; |
| } __packed; |
| |
| struct gpio_charger { |
| struct device *dev; |
| unsigned int irq; |
| unsigned int charge_status_irq; |
| bool wakeup_enabled; |
| |
| struct power_supply *charger; |
| struct power_supply_desc charger_desc; |
| struct gpio_desc *gpiod; |
| struct gpio_desc *charge_status; |
| |
| struct gpio_descs *current_limit_gpios; |
| struct gpio_mapping *current_limit_map; |
| u32 current_limit_map_size; |
| u32 charge_current_limit; |
| }; |
| |
| 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 set_charge_current_limit(struct gpio_charger *gpio_charger, int val) |
| { |
| struct gpio_mapping mapping; |
| int ndescs = gpio_charger->current_limit_gpios->ndescs; |
| struct gpio_desc **gpios = gpio_charger->current_limit_gpios->desc; |
| int i; |
| |
| if (!gpio_charger->current_limit_map_size) |
| return -EINVAL; |
| |
| for (i = 0; i < gpio_charger->current_limit_map_size; i++) { |
| if (gpio_charger->current_limit_map[i].limit_ua <= val) |
| break; |
| } |
| mapping = gpio_charger->current_limit_map[i]; |
| |
| for (i = 0; i < ndescs; i++) { |
| bool val = (mapping.gpiodata >> i) & 1; |
| gpiod_set_value_cansleep(gpios[ndescs-i-1], val); |
| } |
| |
| gpio_charger->charge_current_limit = mapping.limit_ua; |
| |
| dev_dbg(gpio_charger->dev, "set charge current limit to %d (requested: %d)\n", |
| gpio_charger->charge_current_limit, val); |
| |
| return 0; |
| } |
| |
| 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); |
| |
| switch (psp) { |
| case POWER_SUPPLY_PROP_ONLINE: |
| val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod); |
| break; |
| case POWER_SUPPLY_PROP_STATUS: |
| if (gpiod_get_value_cansleep(gpio_charger->charge_status)) |
| val->intval = POWER_SUPPLY_STATUS_CHARGING; |
| else |
| val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; |
| break; |
| case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX: |
| val->intval = gpio_charger->charge_current_limit; |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int gpio_charger_set_property(struct power_supply *psy, |
| enum power_supply_property psp, const union power_supply_propval *val) |
| { |
| struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy); |
| |
| switch (psp) { |
| case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX: |
| return set_charge_current_limit(gpio_charger, val->intval); |
| default: |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int gpio_charger_property_is_writeable(struct power_supply *psy, |
| enum power_supply_property psp) |
| { |
| switch (psp) { |
| case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX: |
| return 1; |
| default: |
| break; |
| } |
| |
| return 0; |
| } |
| |
| static enum power_supply_type gpio_charger_get_type(struct device *dev) |
| { |
| const char *chargetype; |
| |
| if (!device_property_read_string(dev, "charger-type", &chargetype)) { |
| if (!strcmp("unknown", chargetype)) |
| return POWER_SUPPLY_TYPE_UNKNOWN; |
| if (!strcmp("battery", chargetype)) |
| return POWER_SUPPLY_TYPE_BATTERY; |
| if (!strcmp("ups", chargetype)) |
| return POWER_SUPPLY_TYPE_UPS; |
| if (!strcmp("mains", chargetype)) |
| return POWER_SUPPLY_TYPE_MAINS; |
| if (!strcmp("usb-sdp", chargetype)) |
| return POWER_SUPPLY_TYPE_USB; |
| if (!strcmp("usb-dcp", chargetype)) |
| return POWER_SUPPLY_TYPE_USB; |
| if (!strcmp("usb-cdp", chargetype)) |
| return POWER_SUPPLY_TYPE_USB; |
| if (!strcmp("usb-aca", chargetype)) |
| return POWER_SUPPLY_TYPE_USB; |
| } |
| dev_warn(dev, "unknown charger type %s\n", chargetype); |
| |
| return POWER_SUPPLY_TYPE_UNKNOWN; |
| } |
| |
| static int gpio_charger_get_irq(struct device *dev, void *dev_id, |
| struct gpio_desc *gpio) |
| { |
| int ret, irq = gpiod_to_irq(gpio); |
| |
| if (irq > 0) { |
| ret = devm_request_any_context_irq(dev, irq, gpio_charger_irq, |
| IRQF_TRIGGER_RISING | |
| IRQF_TRIGGER_FALLING, |
| dev_name(dev), |
| dev_id); |
| if (ret < 0) { |
| dev_warn(dev, "Failed to request irq: %d\n", ret); |
| irq = 0; |
| } |
| } |
| |
| return irq; |
| } |
| |
| static int init_charge_current_limit(struct device *dev, |
| struct gpio_charger *gpio_charger) |
| { |
| int i, len; |
| u32 cur_limit = U32_MAX; |
| |
| gpio_charger->current_limit_gpios = devm_gpiod_get_array_optional(dev, |
| "charge-current-limit", GPIOD_OUT_LOW); |
| if (IS_ERR(gpio_charger->current_limit_gpios)) { |
| dev_err(dev, "error getting current-limit GPIOs\n"); |
| return PTR_ERR(gpio_charger->current_limit_gpios); |
| } |
| |
| if (!gpio_charger->current_limit_gpios) |
| return 0; |
| |
| len = device_property_read_u32_array(dev, "charge-current-limit-mapping", |
| NULL, 0); |
| if (len < 0) |
| return len; |
| |
| if (len == 0 || len % 2) { |
| dev_err(dev, "invalid charge-current-limit-mapping length\n"); |
| return -EINVAL; |
| } |
| |
| gpio_charger->current_limit_map = devm_kmalloc_array(dev, |
| len / 2, sizeof(*gpio_charger->current_limit_map), GFP_KERNEL); |
| if (!gpio_charger->current_limit_map) |
| return -ENOMEM; |
| |
| gpio_charger->current_limit_map_size = len / 2; |
| |
| len = device_property_read_u32_array(dev, "charge-current-limit-mapping", |
| (u32*) gpio_charger->current_limit_map, len); |
| if (len < 0) |
| return len; |
| |
| for (i=0; i < gpio_charger->current_limit_map_size; i++) { |
| if (gpio_charger->current_limit_map[i].limit_ua > cur_limit) { |
| dev_err(dev, "charge-current-limit-mapping not sorted by current in descending order\n"); |
| return -EINVAL; |
| } |
| |
| cur_limit = gpio_charger->current_limit_map[i].limit_ua; |
| } |
| |
| /* default to smallest current limitation for safety reasons */ |
| len = gpio_charger->current_limit_map_size - 1; |
| set_charge_current_limit(gpio_charger, |
| gpio_charger->current_limit_map[len].limit_ua); |
| |
| return 0; |
| } |
| |
| /* |
| * The entries will be overwritten by driver's probe routine depending |
| * on the available features. This list ensures, that the array is big |
| * enough for all optional features. |
| */ |
| static enum power_supply_property gpio_charger_properties[] = { |
| POWER_SUPPLY_PROP_ONLINE, |
| POWER_SUPPLY_PROP_STATUS, |
| POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX, |
| }; |
| |
| static int gpio_charger_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| const struct gpio_charger_platform_data *pdata = dev->platform_data; |
| struct power_supply_config psy_cfg = {}; |
| struct gpio_charger *gpio_charger; |
| struct power_supply_desc *charger_desc; |
| struct gpio_desc *charge_status; |
| int charge_status_irq; |
| int ret; |
| int num_props = 0; |
| |
| if (!pdata && !dev->of_node) { |
| dev_err(dev, "No platform data\n"); |
| return -ENOENT; |
| } |
| |
| gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL); |
| if (!gpio_charger) |
| return -ENOMEM; |
| gpio_charger->dev = dev; |
| |
| /* |
| * 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_optional(dev, NULL, GPIOD_IN); |
| if (IS_ERR(gpio_charger->gpiod)) { |
| /* Just try again if this happens */ |
| return dev_err_probe(dev, PTR_ERR(gpio_charger->gpiod), |
| "error getting GPIO descriptor\n"); |
| } |
| |
| if (gpio_charger->gpiod) { |
| gpio_charger_properties[num_props] = POWER_SUPPLY_PROP_ONLINE; |
| num_props++; |
| } |
| |
| charge_status = devm_gpiod_get_optional(dev, "charge-status", GPIOD_IN); |
| if (IS_ERR(charge_status)) |
| return PTR_ERR(charge_status); |
| if (charge_status) { |
| gpio_charger->charge_status = charge_status; |
| gpio_charger_properties[num_props] = POWER_SUPPLY_PROP_STATUS; |
| num_props++; |
| } |
| |
| ret = init_charge_current_limit(dev, gpio_charger); |
| if (ret < 0) |
| return ret; |
| if (gpio_charger->current_limit_map) { |
| gpio_charger_properties[num_props] = |
| POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX; |
| num_props++; |
| } |
| |
| charger_desc = &gpio_charger->charger_desc; |
| charger_desc->properties = gpio_charger_properties; |
| charger_desc->num_properties = num_props; |
| charger_desc->get_property = gpio_charger_get_property; |
| charger_desc->set_property = gpio_charger_set_property; |
| charger_desc->property_is_writeable = |
| gpio_charger_property_is_writeable; |
| |
| psy_cfg.of_node = dev->of_node; |
| psy_cfg.drv_data = gpio_charger; |
| |
| if (pdata) { |
| charger_desc->name = pdata->name; |
| charger_desc->type = pdata->type; |
| psy_cfg.supplied_to = pdata->supplied_to; |
| psy_cfg.num_supplicants = pdata->num_supplicants; |
| } else { |
| charger_desc->name = dev->of_node->name; |
| charger_desc->type = gpio_charger_get_type(dev); |
| } |
| |
| if (!charger_desc->name) |
| charger_desc->name = pdev->name; |
| |
| gpio_charger->charger = devm_power_supply_register(dev, charger_desc, |
| &psy_cfg); |
| if (IS_ERR(gpio_charger->charger)) { |
| ret = PTR_ERR(gpio_charger->charger); |
| dev_err(dev, "Failed to register power supply: %d\n", ret); |
| return ret; |
| } |
| |
| gpio_charger->irq = gpio_charger_get_irq(dev, gpio_charger->charger, |
| gpio_charger->gpiod); |
| |
| charge_status_irq = gpio_charger_get_irq(dev, gpio_charger->charger, |
| gpio_charger->charge_status); |
| gpio_charger->charge_status_irq = charge_status_irq; |
| |
| platform_set_drvdata(pdev, gpio_charger); |
| |
| device_init_wakeup(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 gpio_charger *gpio_charger = dev_get_drvdata(dev); |
| |
| 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 <lars@metafoo.de>"); |
| MODULE_DESCRIPTION("Driver for chargers only communicating via GPIO(s)"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:gpio-charger"); |