Device migrations and driver improvements (#576)

Drivers/axp192-module/bindings/x-powers,axp192.yaml

@@ -3,3 +3,64 @@ description: X-Powers AXP192 power management IC
 include: ["i2c-device.yaml"]
 
 compatible: "x-powers,axp192"
+
+properties:
+  dcdc1-voltage:
+    type: int
+    default: 0
+    description: DCDC1 rail voltage in mV (700-3500). 0 leaves the voltage untouched.
+  dcdc1-enable:
+    type: boolean
+    default: false
+    description: >
+      Enable the DCDC1 rail. Unconditionally applied like any other boolean devicetree property -
+      false actively disables it, so a board whose SoC is powered from DCDC1 must set this.
+  dcdc2-voltage:
+    type: int
+    default: 0
+    description: DCDC2 rail voltage in mV (700-2275). 0 leaves the voltage untouched.
+  dcdc2-enable:
+    type: boolean
+    default: false
+    description: Enable the DCDC2 rail. See dcdc1-enable for why false actively disables it.
+  dcdc3-voltage:
+    type: int
+    default: 0
+    description: DCDC3 rail voltage in mV (700-3500). 0 leaves the voltage untouched.
+  dcdc3-enable:
+    type: boolean
+    default: false
+    description: Enable the DCDC3 rail. See dcdc1-enable for why false actively disables it.
+  ldo2-voltage:
+    type: int
+    default: 0
+    description: LDO2 rail voltage in mV (1800-3300). 0 leaves the voltage untouched.
+  ldo2-enable:
+    type: boolean
+    default: false
+    description: Enable the LDO2 rail. See dcdc1-enable for why false actively disables it.
+  ldo3-voltage:
+    type: int
+    default: 0
+    description: LDO3 rail voltage in mV (1800-3300). 0 leaves the voltage untouched.
+  ldo3-enable:
+    type: boolean
+    default: false
+    description: Enable the LDO3 rail. See dcdc1-enable for why false actively disables it.
+  exten-enable:
+    type: boolean
+    default: false
+    description: >
+      Enable the EXTEN output switch. No voltage control (see AXP192_RAIL_EXTEN); see
+      dcdc1-enable for why false actively disables it.
+  gpio1-pwm:
+    type: boolean
+    default: false
+    description: Configure GPIO1 as the PWM1 output instead of GPIO/ADC input/output.
+  gpio1-pwm1-duty-cycle:
+    type: int
+    default: 0
+    min: 0
+    max: 255
+    description: >
+      PWM1 duty cycle (0 = always low, 255 = always high). Only applied when gpio1-pwm is set.

Drivers/axp192-module/include/drivers/axp192.h

@@ -15,6 +15,32 @@ extern "C" {
 struct Axp192Config {
     /** Address on bus */
     uint8_t address;
+    /**
+     * Rail voltage/enable settings, applied once at driver start (see axp192_set_rail_voltage()/
+     * axp192_set_rail_enabled()). Each "enable" flag is unconditionally applied - false (the yaml
+     * default) actively disables the rail, same as every other boolean devicetree property in
+     * this codebase (e.g. reset-active-high, swap-xy: absence means false, not "leave alone").
+     * A board must explicitly set every rail it needs kept on, including ones a board's hardware
+     * happens to power up with by default (e.g. DCDC1, which is the SoC's own supply on some
+     * boards) - see m5stack-core2's devicetree for a worked example. Voltage of 0 means "don't
+     * call axp192_set_rail_voltage() for this rail" (0mV is outside every rail's valid range).
+     */
+    uint16_t dcdc1_voltage_mv;
+    bool dcdc1_enable;
+    uint16_t dcdc2_voltage_mv;
+    bool dcdc2_enable;
+    uint16_t dcdc3_voltage_mv;
+    bool dcdc3_enable;
+    uint16_t ldo2_voltage_mv;
+    bool ldo2_enable;
+    uint16_t ldo3_voltage_mv;
+    bool ldo3_enable;
+    /** EXTEN has no voltage control (see AXP192_RAIL_EXTEN), hence no exten_voltage_mv field. */
+    bool exten_enable;
+    /** Configures GPIO1 as the PWM1 output (see axp192_set_gpio1_pwm1_output()). */
+    bool gpio1_pwm;
+    /** Applied only when gpio1_pwm is true (see axp192_set_pwm1_duty_cycle()). */
+    uint8_t gpio1_pwm1_duty_cycle;
 };
 
 /** Switchable/adjustable power rails of the AXP192. */

Drivers/axp192-module/source/axp192.cpp

@@ -12,6 +12,7 @@
 #include <new>
 
 #define GET_CONFIG(device) (static_cast<const Axp192Config*>((device)->config))
+constexpr auto* TAG = "AXP192";
 
 /** Reference: https://github.com/tuupola/axp192 (register map and ADC/voltage formulas) */
 static constexpr uint8_t REG_MODE_CHGSTATUS = 0x01U;               // bit6: battery is charging
@@ -404,10 +405,73 @@ static void destroy_power_supply_child(Device* child) {
 
 // endregion
 
+// region Devicetree-configured bring-up
+
+static error_t apply_rail_config(Device* device, Axp192Rail rail, uint16_t voltage_mv, bool enable) {
+    if (voltage_mv != 0U) {
+        error_t error = axp192_set_rail_voltage(device, rail, voltage_mv);
+        if (error != ERROR_NONE) {
+            return error;
+        }
+    }
+    return axp192_set_rail_enabled(device, rail, enable);
+}
+
+// Applies the devicetree's rail voltage/enable and GPIO1 PWM settings, replacing what boards
+// (e.g. m5stack-core2) used to do by hand via a device_listener after DEVICE_EVENT_STARTED.
+static error_t apply_devicetree_config(Device* device) {
+    const auto* config = GET_CONFIG(device);
+
+    error_t error = apply_rail_config(device, AXP192_RAIL_DCDC1, config->dcdc1_voltage_mv, config->dcdc1_enable);
+    if (error != ERROR_NONE) {
+        return error;
+    }
+    error = apply_rail_config(device, AXP192_RAIL_DCDC2, config->dcdc2_voltage_mv, config->dcdc2_enable);
+    if (error != ERROR_NONE) {
+        return error;
+    }
+    error = apply_rail_config(device, AXP192_RAIL_DCDC3, config->dcdc3_voltage_mv, config->dcdc3_enable);
+    if (error != ERROR_NONE) {
+        return error;
+    }
+    error = apply_rail_config(device, AXP192_RAIL_LDO2, config->ldo2_voltage_mv, config->ldo2_enable);
+    if (error != ERROR_NONE) {
+        return error;
+    }
+    error = apply_rail_config(device, AXP192_RAIL_LDO3, config->ldo3_voltage_mv, config->ldo3_enable);
+    if (error != ERROR_NONE) {
+        return error;
+    }
+    error = axp192_set_rail_enabled(device, AXP192_RAIL_EXTEN, config->exten_enable);
+    if (error != ERROR_NONE) {
+        return error;
+    }
+
+    if (config->gpio1_pwm) {
+        error = axp192_set_pwm1_duty_cycle(device, config->gpio1_pwm1_duty_cycle);
+        if (error != ERROR_NONE) {
+            return error;
+        }
+        error = axp192_set_gpio1_pwm1_output(device);
+        if (error != ERROR_NONE) {
+            return error;
+        }
+    }
+
+    return ERROR_NONE;
+}
+
+// endregion
+
 static error_t start(Device* device) {
     auto* parent = device_get_parent(device);
     check(device_get_type(parent) == &I2C_CONTROLLER_TYPE);
 
+    if (apply_devicetree_config(device) != ERROR_NONE) {
+        LOG_E(TAG, "Failed to apply devicetree-configured rail/GPIO1 settings");
+        return ERROR_RESOURCE;
+    }
+
     auto* internal = new(std::nothrow) Axp192Internal();
     if (internal == nullptr) {
         return ERROR_OUT_OF_MEMORY;