From be2919d8355e4651386ad2fb61ddb6efe4533b1b Mon Sep 17 00:00:00 2001 From: Sebastian Reichel Date: Sat, 6 Jun 2020 00:44:00 +0200 Subject: [PATCH] power: supply: gpio-charger: add charge-current-limit feature Add new charge-current-limit feature to gpio-charger. Reviewed-by: Linus Walleij Signed-off-by: Sebastian Reichel --- .../bindings/power/supply/gpio-charger.yaml | 31 +++++ drivers/power/supply/gpio-charger.c | 140 +++++++++++++++++++++ 2 files changed, 171 insertions(+) diff --git a/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml b/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml index 6244b8e..89f8e2b 100644 --- a/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml +++ b/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml @@ -39,6 +39,25 @@ properties: maxItems: 1 description: GPIO indicating the charging status + charge-current-limit-gpios: + minItems: 1 + maxItems: 32 + description: GPIOs used for current limiting + + charge-current-limit-mapping: + description: List of tuples with current in uA and a GPIO bitmap (in + this order). The tuples must be provided in descending order of the + current limit. + $ref: /schemas/types.yaml#/definitions/uint32-matrix + items: + items: + - description: + Current limit in uA + - description: + Encoded GPIO setting. Bit 0 represents last GPIO from the + charge-current-limit-gpios property. Bit 1 second to last + GPIO and so on. + required: - compatible @@ -47,6 +66,12 @@ anyOf: - gpios - required: - charge-status-gpios + - required: + - charge-current-limit-gpios + +dependencies: + charge-current-limit-gpios: [ charge-current-limit-mapping ] + charge-current-limit-mapping: [ charge-current-limit-gpios ] additionalProperties: false @@ -60,4 +85,10 @@ examples: gpios = <&gpd 28 GPIO_ACTIVE_LOW>; charge-status-gpios = <&gpc 27 GPIO_ACTIVE_LOW>; + + charge-current-limit-gpios = <&gpioA 11 GPIO_ACTIVE_HIGH>, + <&gpioA 12 GPIO_ACTIVE_HIGH>; + charge-current-limit-mapping = <2500000 0x00>, // 2.5 A => both GPIOs low + <700000 0x01>, // 700 mA => GPIO A.12 high + <0 0x02>; // 0 mA => GPIO A.11 high }; diff --git a/drivers/power/supply/gpio-charger.c b/drivers/power/supply/gpio-charger.c index d7aff28..68212b3 100644 --- a/drivers/power/supply/gpio-charger.c +++ b/drivers/power/supply/gpio-charger.c @@ -17,7 +17,13 @@ #include +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; @@ -26,6 +32,11 @@ struct gpio_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) @@ -42,6 +53,35 @@ 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) { @@ -57,6 +97,9 @@ static int gpio_charger_get_property(struct power_supply *psy, 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; } @@ -64,6 +107,34 @@ 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; @@ -111,6 +182,61 @@ static int gpio_charger_get_irq(struct device *dev, void *dev_id, 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 @@ -119,6 +245,7 @@ static int gpio_charger_get_irq(struct device *dev, void *dev_id, 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) @@ -141,6 +268,7 @@ 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 @@ -167,10 +295,22 @@ static int gpio_charger_probe(struct platform_device *pdev) 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; -- 2.7.4