Add usage details for the two new debugfs endpoints for 2nd Gen devices: read_black_box and write_config Signed-off-by: Grant Peltier <grantpeltier93@xxxxxxxxx> --- Documentation/hwmon/isl68137.rst | 34 +++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/Documentation/hwmon/isl68137.rst b/Documentation/hwmon/isl68137.rst index 0e71b22047f8..c5f7b2981db6 100644 --- a/Documentation/hwmon/isl68137.rst +++ b/Documentation/hwmon/isl68137.rst @@ -423,7 +423,8 @@ Beyond the normal sysfs pmbus attributes, the driver exposes a control attribute for the ISL68137. For 2nd generation Renesas digital multiphase voltage regulators, only the -normal sysfs pmbus attributes are supported. +normal sysfs pmbus attributes are supported. However, 2nd generation devices do +have additional debugfs features which are detailed below. ISL68137 sysfs attributes ------------------------- @@ -603,3 +604,34 @@ temp[1-7]_crit_alarm Chip temperature critical high alarm temp[1-7]_max Maximum temperature temp[1-7]_max_alarm Chip temperature high alarm ======================= ========================================== + +debugfs features (Gen 2 ONLY) +----------------------------- + +If you have debugfs enabled, two file endpoints will be created under +`/sys/kernel/debug/pmbus/<device-id>` when you instantiate a 2nd generation +device: `read_black_box` and `write_config`. + +`read_black_box` is a read-only file. When read, the driver will attempt to read +the contents of the device's fault recording RAM segment called "Black Box". The +RAM segment is then printed to the file as hex formatted strings. For easier +consumption, the 128-byte segment is broken up into 32 4-byte little-endian +lines (i.e. each line starts with the least significant byte). See your device's +datasheet for information regarding how to parse the data. + +.. warning:: + When using `write_config`, only use hex files as they are exported from the + Renesas Power Navigator application: + https://www.renesas.com/us/en/products/power-management/digital-power/powernavigator.html + +`write_config` is a write-only file. This endpoint expects the contents of a +configuration hex file specific to your device exactly as it is exported from +the Renesas Power Navigator application. When this endpoint is written to, the +driver will attempt to write the contents of the file down to one or more of the +device's NVM slots and will return a standard error code if any part of the +process fails. Be careful when using this feature as writing an unstable +configuration to your device may may cause it to misbehave. Each device also has +a fixed number of NVM writes allowed. Consult the datasheet for your device for +more information about NVM configuration options. Finally, note that you will +have to power cycle your device in order for NVM configuration changes to take +effect. -- 2.20.1
