diff options
Diffstat (limited to 'drivers/power/supply/gpio-charger.c')
| -rw-r--r-- | drivers/power/supply/gpio-charger.c | 286 |
1 files changed, 231 insertions, 55 deletions
diff --git a/drivers/power/supply/gpio-charger.c b/drivers/power/supply/gpio-charger.c index 7e4f11d5a230..2504190eba82 100644 --- a/drivers/power/supply/gpio-charger.c +++ b/drivers/power/supply/gpio-charger.c @@ -1,20 +1,10 @@ +// 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 - * - * 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> /* For legacy platform data */ #include <linux/init.h> #include <linux/interrupt.h> #include <linux/kernel.h> @@ -27,13 +17,26 @@ #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) @@ -50,6 +53,44 @@ 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; + } + + /* + * If a valid charge current limit isn't found, default to smallest + * current limitation for safety reasons. + */ + if (i >= gpio_charger->current_limit_map_size) + i = gpio_charger->current_limit_map_size - 1; + + 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) { @@ -59,6 +100,15 @@ static int gpio_charger_get_property(struct power_supply *psy, 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; } @@ -66,6 +116,34 @@ static int gpio_charger_get_property(struct power_supply *psy, 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; @@ -93,8 +171,103 @@ static enum power_supply_type gpio_charger_get_type(struct device *dev) 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; + bool set_def_limit; + u32 def_limit; + + 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; + + set_def_limit = !device_property_read_u32(dev, + "charge-current-limit-default-microamp", + &def_limit); + 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; + if (set_def_limit && def_limit == cur_limit) { + set_charge_current_limit(gpio_charger, cur_limit); + return 0; + } + } + + if (set_def_limit) + dev_warn(dev, "charge-current-limit-default-microamp %u not listed in charge-current-limit-mapping\n", + def_limit); + + /* 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) @@ -104,8 +277,10 @@ static int gpio_charger_probe(struct platform_device *pdev) struct power_supply_config psy_cfg = {}; struct gpio_charger *gpio_charger; struct power_supply_desc *charger_desc; - unsigned long flags; - int irq, ret; + 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"); @@ -115,48 +290,51 @@ static int gpio_charger_probe(struct platform_device *pdev) 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(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) && !dev->of_node) { - /* Non-DT: use legacy GPIO numbers */ - if (!gpio_is_valid(pdata->gpio)) { - dev_err(dev, "Invalid gpio pin in pdata\n"); - return -EINVAL; - } - flags = GPIOF_IN; - if (pdata->gpio_active_low) - flags |= GPIOF_ACTIVE_LOW; - ret = devm_gpio_request_one(dev, pdata->gpio, flags, - dev_name(dev)); - if (ret) { - dev_err(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)) { + gpio_charger->gpiod = devm_gpiod_get_optional(dev, NULL, GPIOD_IN); + 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(dev, "error getting GPIO descriptor\n"); - return PTR_ERR(gpio_charger->gpiod); + 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 = ARRAY_SIZE(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.fwnode = dev_fwnode(dev); psy_cfg.drv_data = gpio_charger; if (pdata) { @@ -180,20 +358,18 @@ static int gpio_charger_probe(struct platform_device *pdev) return ret; } - irq = gpiod_to_irq(gpio_charger->gpiod); - if (irq > 0) { - ret = devm_request_any_context_irq(dev, irq, gpio_charger_irq, - IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, - dev_name(dev), gpio_charger->charger); - if (ret < 0) - dev_warn(dev, "Failed to request irq: %d\n", ret); - else - gpio_charger->irq = irq; - } + 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); + ret = devm_device_init_wakeup(dev); + if (ret) + return dev_err_probe(dev, ret, "Failed to init wakeup\n"); return 0; } @@ -243,6 +419,6 @@ static struct platform_driver gpio_charger_driver = { 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_DESCRIPTION("Driver for chargers only communicating via GPIO(s)"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:gpio-charger"); |