Charger (gpio-charger)

Charger as <tt>rt_power_supply</tt>

Chargers are not a separate class. A charger is a **struct rt_power_supply** with USB/mains **type** and properties such as **ONLINE**, **STATUS**, **CONSTANT_CHARGE_CURRENT_MAX**.

Core registration flow: Power supply.

Kconfig: **RT_POWER_SUPPLY_CHARGER_GPIO** → **components/drivers/power/supply/gpio-charger.c**.

---

Registration flow (<tt>gpio-charger</tt>)

RT_PLATFORM_DRIVER_EXPORT(gpio_charger_driver)
        |
        v
gpio_charger_probe(pdev)
        |
        +-- rt_pin_get_named_pin (VBUS / status GPIOs)
        +-- optional charge-current-limit GPIOs + mapping table
        +-- parse charger-type → psy->type
        +-- build gpio_charger_properties[] (only supported props)
        +-- psy->dev = &pdev->parent; psy->ops = &gpio_charger_ops
        +-- rt_power_supply_register(&gpioc->parent)
        +-- GPIO IRQ → gpio_charger_isr → rt_power_supply_changed()

---

Device tree (typical)

charger {
    compatible = "gpio-charger";
    charger-type = "usb-dcp";
    gpios = <&gpio0 12 GPIO_ACTIVE_HIGH>;          /* online */
    charge-status-gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
    charge-current-limit-gpios = <&gpio0 14>, <&gpio0 15>;
    charge-current-limit-mapping = <100000 0>, <500000 1>, <1500000 3>;
};

Properties actually exposed depend on which GPIOs/mapping are present — the driver builds **properties[]** dynamically in **probe**.

---

<tt>get_property</tt> / <tt>set_property</tt>

Property	Behavior
**ONLINE**	Read VBUS GPIO
**STATUS**	Charging vs not from **charge-status** GPIO
**CONSTANT_CHARGE_CURRENT_MAX**	Mapping table + limit GPIOs; **set_property** selects limit

---

Emulator

**emu-power.c** (**RT_POWER_SUPPLY_EMU**): registers test battery + charger; MSH **emu_charger** toggles state for thermal/PM tests.

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See also

• Power supply
• Regulator
• PIN Device
• components/drivers/power/supply/gpio-charger.c