mag_detect.hpp

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/*
 * SPDX-FileCopyrightText: 2026 M5Stack Technology CO LTD
 *
 * SPDX-License-Identifier: MIT
 */
#ifndef M5_UNIT_IMU_IMU_MAG_DETECT_HPP
#define M5_UNIT_IMU_IMU_MAG_DETECT_HPP
 
#include <cstdint>
 
namespace m5 {
namespace unit {
namespace imu {
 
enum class MagKind : uint8_t {
    None,     
    BMM150,   
    AK8963,   
    MAG3110,  
};
 
template <class ReadReg>
MagKind detectBuiltinMag(ReadReg read)
{
    uint8_t id{};
    if (read(static_cast<uint8_t>(0x0C), static_cast<uint8_t>(0x00), id) && id == 0x48) {
        return MagKind::AK8963;
    }
    if (read(static_cast<uint8_t>(0x0E), static_cast<uint8_t>(0x07), id) && id == 0xC4) {
        return MagKind::MAG3110;
    }
    if (read(static_cast<uint8_t>(0x10), static_cast<uint8_t>(0x40), id)) {
        return MagKind::BMM150;
    }
    return MagKind::None;
}
 
template <class ReadReg, class WriteReg>
bool enableAuxBypass(ReadReg read, WriteReg write)
{
    uint8_t id{};
    if (!read(static_cast<uint8_t>(0x68), static_cast<uint8_t>(0x75), id) || id != 0x71) {
        return false;  // not an MPU9250 -> nothing to bypass
    }
    uint8_t user_ctrl{};
    if (!read(static_cast<uint8_t>(0x68), static_cast<uint8_t>(0x6A), user_ctrl)) {
        return false;
    }
    user_ctrl = static_cast<uint8_t>(user_ctrl & ~0x20);  // clear I2C_MST_EN (bit5)
    if (!write(static_cast<uint8_t>(0x68), static_cast<uint8_t>(0x6A), user_ctrl)) {
        return false;
    }
    if (!write(static_cast<uint8_t>(0x68), static_cast<uint8_t>(0x37), static_cast<uint8_t>(0x02))) {
        return false;  // INT_PIN_CFG BYPASS_EN (bit1)
    }
    return true;
}
 
}  // namespace imu
}  // namespace unit
}  // namespace m5
#endif