| .. SPDX-License-Identifier: GPL-2.0 | 
 |  | 
 | Kernel driver sg2042-mcu | 
 | ======================== | 
 |  | 
 | Supported chips: | 
 |  | 
 |   * Onboard MCU for sg2042 | 
 |  | 
 |     Addresses scanned: - | 
 |  | 
 |     Prefix: 'sg2042-mcu' | 
 |  | 
 | Authors: | 
 |  | 
 |   - Inochi Amaoto <inochiama@outlook.com> | 
 |  | 
 | Description | 
 | ----------- | 
 |  | 
 | This driver supprts hardware monitoring for onboard MCU with | 
 | i2c interface. | 
 |  | 
 | Usage Notes | 
 | ----------- | 
 |  | 
 | This driver does not auto-detect devices. You will have to instantiate | 
 | the devices explicitly. | 
 | Please see Documentation/i2c/instantiating-devices.rst for details. | 
 |  | 
 | Sysfs Attributes | 
 | ---------------- | 
 |  | 
 | The following table shows the standard entries support by the driver: | 
 |  | 
 | ================= ===================================================== | 
 | Name              Description | 
 | ================= ===================================================== | 
 | temp1_input       Measured temperature of SoC | 
 | temp1_crit        Critical high temperature | 
 | temp1_crit_hyst   hysteresis temperature restore from Critical | 
 | temp2_input       Measured temperature of the base board | 
 | ================= ===================================================== | 
 |  | 
 | The following table shows the extra entries support by the driver | 
 | (the MCU device is in i2c subsystem): | 
 |  | 
 | ================= ======= ============================================= | 
 | Name              Perm    Description | 
 | ================= ======= ============================================= | 
 | reset_count       RO      Reset count of the SoC | 
 | uptime            RO      Seconds after the MCU is powered | 
 | reset_reason      RO      Reset reason for the last reset | 
 | repower_policy    RW      Execution policy when triggering repower | 
 | ================= ======= ============================================= | 
 |  | 
 | ``repower_policy`` | 
 |   The repower is triggered when the temperature of the SoC falls below | 
 |   the hysteresis temperature after triggering a shutdown due to | 
 |   reaching the critical temperature. | 
 |   The valid values for this entry are "repower" and "keep". "keep" will | 
 |   leave the SoC down when the triggering repower, and "repower" will | 
 |   boot the SoC. | 
 |  | 
 | Debugfs Interfaces | 
 | ------------------ | 
 |  | 
 | If debugfs is available, this driver exposes some hardware specific | 
 | data in ``/sys/kernel/debug/sg2042-mcu/*/``. | 
 |  | 
 | ================= ======= ============================================= | 
 | Name              Format  Description | 
 | ================= ======= ============================================= | 
 | firmware_version  0x%02x  firmware version of the MCU | 
 | pcb_version       0x%02x  version number of the base board | 
 | board_type        0x%02x  identifiers for the base board | 
 | mcu_type          %d      type of the MCU: 0 is STM32, 1 is GD32 | 
 | ================= ======= ============================================= |