The patch series adds debugfs features for 2nd generation Renesas digital
multiphase voltage regulators. The new debugfs endpoints allow users to
utilize features of the VR that are not compatible with sysfs.
The series contains 2 patches:
- patch #1 adds the new debugfs features to the isl68137 driver
- patch #2 adds documentation for the new debugfs endpoints
Grant Peltier (2):
hwmon: (pmbus/isl68137) add debugfs config and black box endpoints
docs: hwmon: Update driver documentation for debugfs
Documentation/hwmon/isl68137.rst | 34 ++-
drivers/hwmon/pmbus/isl68137.c | 490 ++++++++++++++++++++++++++++++-
2 files changed, 520 insertions(+), 4 deletions(-)
--
2.20.1
Add usage details for the two new debugfs endpoints for 2nd Gen devices:
read_black_box and write_config
Signed-off-by: Grant Peltier <[email protected]>
---
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