1.. SPDX-License-Identifier: GPL-2.0
 2
 3Kernel driver sg2042-mcu
 4========================
 5
 6Supported chips:
 7
 8  * Onboard MCU for sg2042
 9
10    Addresses scanned: -
11
12    Prefix: 'sg2042-mcu'
13
14Authors:
15
16  - Inochi Amaoto <inochiama@outlook.com>
17
18Description
19-----------
20
21This driver supprts hardware monitoring for onboard MCU with
22i2c interface.
23
24Usage Notes
25-----------
26
27This driver does not auto-detect devices. You will have to instantiate
28the devices explicitly.
29Please see Documentation/i2c/instantiating-devices.rst for details.
30
31Sysfs Attributes
32----------------
33
34The following table shows the standard entries support by the driver:
35
36================= =====================================================
37Name              Description
38================= =====================================================
39temp1_input       Measured temperature of SoC
40temp1_crit        Critical high temperature
41temp1_crit_hyst   hysteresis temperature restore from Critical
42temp2_input       Measured temperature of the base board
43================= =====================================================
44
45The following table shows the extra entries support by the driver
46(the MCU device is in i2c subsystem):
47
48================= ======= =============================================
49Name              Perm    Description
50================= ======= =============================================
51reset_count       RO      Reset count of the SoC
52uptime            RO      Seconds after the MCU is powered
53reset_reason      RO      Reset reason for the last reset
54repower_policy    RW      Execution policy when triggering repower
55================= ======= =============================================
56
57``repower_policy``
58  The repower is triggered when the temperature of the SoC falls below
59  the hysteresis temperature after triggering a shutdown due to
60  reaching the critical temperature.
61  The valid values for this entry are "repower" and "keep". "keep" will
62  leave the SoC down when the triggering repower, and "repower" will
63  boot the SoC.
64
65Debugfs Interfaces
66------------------
67
68If debugfs is available, this driver exposes some hardware specific
69data in ``/sys/kernel/debug/sg2042-mcu/*/``.
70
71================= ======= =============================================
72Name              Format  Description
73================= ======= =============================================
74firmware_version  0x%02x  firmware version of the MCU
75pcb_version       0x%02x  version number of the base board
76board_type        0x%02x  identifiers for the base board
77mcu_type          %d      type of the MCU: 0 is STM32, 1 is GD32
78================= ======= =============================================