Device migrations, driver migrations and more (#575)

Drivers/ina226-module/bindings/ti,ina226.yaml

@@ -10,3 +10,16 @@ properties:
     required: true
     # shunt value should be a minimum of 1
     description: Shunt resistor value in milliohms
+  power-supply:
+    type: boolean
+    default: false
+    description: Expose a power-supply device that reports battery voltage/capacity read from the INA226's bus voltage input
+  power-supply-reference-voltage-mv:
+    type: int
+    default: 4200
+    description: Battery voltage (in mV) considered 100% capacity, used to compute POWER_SUPPLY_PROP_CAPACITY
+  power-supply-min-voltage-mv:
+    type: int
+    default: 3200
+    description: Battery voltage (in mV) considered 0% capacity, used to compute POWER_SUPPLY_PROP_CAPACITY.
+      Depends on the pack's cell count - the default is a rough 1S LiPo floor.

Drivers/ina226-module/include/drivers/ina226.h

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 #pragma once
 
+#include <stdbool.h>
 #include <stdint.h>
 #include <tactility/error.h>
 
@@ -13,6 +14,12 @@ extern "C" {
 struct Ina226Config {
     uint8_t address;
     uint16_t shunt_milliohms;
+    /** Expose a power-supply child device that reports battery voltage/capacity off the bus voltage reading */
+    bool power_supply;
+    /** Battery voltage (mV) considered 100% capacity, used to derive POWER_SUPPLY_PROP_CAPACITY */
+    uint32_t power_supply_reference_voltage_mv;
+    /** Battery voltage (mV) considered 0% capacity, used to derive POWER_SUPPLY_PROP_CAPACITY */
+    uint32_t power_supply_min_voltage_mv;
 };
 
 /** Bus voltage in volts (1.25 mV/LSB) */

Drivers/ina226-module/source/ina226.cpp

@@ -1,11 +1,16 @@
 // SPDX-License-Identifier: Apache-2.0
 #include <drivers/ina226.h>
 #include <ina226_module.h>
+#include <tactility/check.h>
 #include <tactility/device.h>
 #include <tactility/drivers/i2c_controller.h>
+#include <tactility/drivers/power_supply.h>
 #include <tactility/log.h>
 
-#define TAG "INA226"
+#include <cstdlib>
+#include <new>
+
+constexpr auto* TAG = "INA226";
 
 // ---------------------------------------------------------------------------
 // Register map
@@ -30,6 +35,124 @@ static constexpr TickType_t TIMEOUT = pdMS_TO_TICKS(50);
 
 #define GET_CONFIG(device) (static_cast<const Ina226Config*>((device)->config))
 
+struct Ina226Internal {
+    Device* power_supply_device;
+};
+
+// ---------------------------------------------------------------------------
+// Power supply
+// ---------------------------------------------------------------------------
+
+static bool ps_supports_property(Device*, PowerSupplyProperty property) {
+    return property == POWER_SUPPLY_PROP_VOLTAGE || property == POWER_SUPPLY_PROP_CAPACITY;
+}
+
+// battery_mv <= min_mv -> 0%, battery_mv >= reference_mv -> 100%, linear in between. min_mv is
+// configurable (power-supply-min-voltage-mv) since it depends on the pack's cell count - a 1S
+// LiPo's empty floor is very different from e.g. a 2S pack's.
+static int estimate_capacity_from_mv(int battery_mv, uint32_t min_mv, uint32_t reference_mv) {
+    if ((uint32_t)battery_mv <= min_mv) return 0;
+    if ((uint32_t)battery_mv >= reference_mv) return 100;
+    return (battery_mv - (int)min_mv) * 100 / ((int)reference_mv - (int)min_mv);
+}
+
+static error_t ps_get_property(Device* device, PowerSupplyProperty property, PowerSupplyPropertyValue* out_value) {
+    if (property != POWER_SUPPLY_PROP_VOLTAGE && property != POWER_SUPPLY_PROP_CAPACITY) {
+        return ERROR_NOT_SUPPORTED;
+    }
+
+    auto* parent = device_get_parent(device);
+
+    float volts;
+    error_t error = ina226_read_bus_voltage(parent, &volts);
+    if (error != ERROR_NONE) {
+        return error;
+    }
+    int battery_mv = static_cast<int>(volts * 1000.0f);
+
+    const auto* parent_config = GET_CONFIG(parent);
+    out_value->int_value = (property == POWER_SUPPLY_PROP_VOLTAGE)
+        ? battery_mv
+        : estimate_capacity_from_mv(battery_mv, parent_config->power_supply_min_voltage_mv, parent_config->power_supply_reference_voltage_mv);
+    return ERROR_NONE;
+}
+
+static bool ps_supports_charge_control(Device*) { return false; }
+static bool ps_is_allowed_to_charge(Device*) { return false; }
+static error_t ps_set_allowed_to_charge(Device*, bool) { return ERROR_NOT_SUPPORTED; }
+static bool ps_supports_quick_charge(Device*) { return false; }
+static bool ps_is_quick_charge_enabled(Device*) { return false; }
+static error_t ps_set_quick_charge_enabled(Device*, bool) { return ERROR_NOT_SUPPORTED; }
+static bool ps_supports_power_off(Device*) { return false; }
+static error_t ps_power_off(Device*) { return ERROR_NOT_SUPPORTED; }
+
+static constexpr PowerSupplyApi INA226_POWER_SUPPLY_API = {
+    .supports_property = ps_supports_property,
+    .get_property = ps_get_property,
+    .supports_charge_control = ps_supports_charge_control,
+    .is_allowed_to_charge = ps_is_allowed_to_charge,
+    .set_allowed_to_charge = ps_set_allowed_to_charge,
+    .supports_quick_charge = ps_supports_quick_charge,
+    .is_quick_charge_enabled = ps_is_quick_charge_enabled,
+    .set_quick_charge_enabled = ps_set_quick_charge_enabled,
+    .supports_power_off = ps_supports_power_off,
+    .power_off = ps_power_off,
+};
+
+// Registered (driver_construct_add() in module.cpp) so driver_bind() has a valid ->internal,
+// but never matched against a devicetree node: ina226 wires it up directly by pointer.
+Driver ina226_power_supply_driver = {
+    .name = "ina226-power-supply",
+    .compatible = (const char*[]) { "ina226-power-supply", nullptr },
+    .start_device = nullptr,
+    .stop_device = nullptr,
+    .api = &INA226_POWER_SUPPLY_API,
+    .device_type = &POWER_SUPPLY_TYPE,
+    .owner = &ina226_module,
+    .internal = nullptr
+};
+
+static error_t create_power_supply_child(Device* parent, Device*& out_child) {
+    auto* child = new(std::nothrow) Device { .address = 0, .name = "ina226-power-supply", .config = nullptr, .parent = nullptr, .internal = nullptr };
+    if (child == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    error_t error = device_construct(child);
+    if (error != ERROR_NONE) {
+        delete child;
+        return error;
+    }
+
+    device_set_parent(child, parent);
+    device_set_driver(child, &ina226_power_supply_driver);
+
+    error = device_add(child);
+    if (error != ERROR_NONE) {
+        device_destruct(child);
+        delete child;
+        return error;
+    }
+
+    error = device_start(child);
+    if (error != ERROR_NONE) {
+        device_remove(child);
+        device_destruct(child);
+        delete child;
+        return error;
+    }
+
+    out_child = child;
+    return ERROR_NONE;
+}
+
+static void destroy_power_supply_child(Device* child) {
+    check(device_stop(child) == ERROR_NONE);
+    check(device_remove(child) == ERROR_NONE);
+    check(device_destruct(child) == ERROR_NONE);
+    delete child;
+}
+
 // ---------------------------------------------------------------------------
 // Driver lifecycle
 // ---------------------------------------------------------------------------
@@ -77,6 +200,23 @@ static error_t start(Device* device) {
         return ERROR_RESOURCE;
     }
 
+    auto* internal = static_cast<Ina226Internal*>(malloc(sizeof(Ina226Internal)));
+    if (internal == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+    internal->power_supply_device = nullptr;
+    device_set_driver_data(device, internal);
+
+    if (GET_CONFIG(device)->power_supply) {
+        error_t error = create_power_supply_child(device, internal->power_supply_device);
+        if (error != ERROR_NONE) {
+            LOG_E(TAG, "Failed to create power-supply device");
+            free(internal);
+            device_set_driver_data(device, nullptr);
+            return error;
+        }
+    }
+
     LOG_I(TAG, "INA226 started (addr=0x%02X, shunt=%umΩ, cal=0x%04X)", addr, GET_CONFIG(device)->shunt_milliohms, cal_value);
     return ERROR_NONE;
 }
@@ -88,6 +228,12 @@ static error_t stop(Device* device) {
         return ERROR_RESOURCE;
     }
 
+    auto* internal = static_cast<Ina226Internal*>(device_get_driver_data(device));
+    if (internal->power_supply_device != nullptr) {
+        destroy_power_supply_child(internal->power_supply_device);
+        internal->power_supply_device = nullptr;
+    }
+
     auto addr = GET_CONFIG(device)->address;
 
     // Put device into shutdown mode to save power
@@ -95,6 +241,9 @@ static error_t stop(Device* device) {
         LOG_E(TAG, "Failed to shutdown INA226 (ignored)");
     }
 
+    free(internal);
+    device_set_driver_data(device, nullptr);
+
     return ERROR_NONE;
 }
 

Drivers/ina226-module/source/module.cpp

@@ -6,17 +6,20 @@
 extern "C" {
 
 extern Driver ina226_driver;
+extern Driver ina226_power_supply_driver;
 
 static error_t start() {
     /* We crash when construct fails, because if a single driver fails to construct,
      * there is no guarantee that the previously constructed drivers can be destroyed */
     check(driver_construct_add(&ina226_driver) == ERROR_NONE);
+    check(driver_construct_add(&ina226_power_supply_driver) == ERROR_NONE);
     return ERROR_NONE;
 }
 
 static error_t stop() {
     /* We crash when destruct fails, because if a single driver fails to destruct,
      * there is no guarantee that the previously destroyed drivers can be recovered */
+    check(driver_remove_destruct(&ina226_power_supply_driver) == ERROR_NONE);
     check(driver_remove_destruct(&ina226_driver) == ERROR_NONE);
     return ERROR_NONE;
 }