Hello, v1[1] spent some time in the OpenBMC kernel tree and it shook out a few issues: 1. The machines I was testing against had pre-prammed the installed-bit in FAN_CONFIG_1_2 2. There appears to be a hardware issue with some back-to-back writes to the MAX31785 Point 1. is a policy issue so we should have the ability to specify behaviour in the devicetree. As such the bindings documentation has been updated to suit. Point 2, well, it's a little ugly. We're in contact with Maxim to better understand the nature of the issue. Patch 4 introduces a work-around. I've kept this separate from the introduction of the driver so it's implementation and the demonstration of new pmbus core features isn't obscured. The work-around has proved reliable so-far, across a number of machines. [1] https://lkml.org/lkml/2017/7/27/116 Changes from v1 to v2: * Add the use-stored-presence devicetree property describing the hardware as canonical in terms of fan presence. * Small optimsation in pmbus_update_fans(): Don't write FAN_CONFIG_x_y unless the new value is different to the current value * Update the MAX31785 driver to consume use-stored-presence from the devicetree * Add the back-to-back write work-around Changes between RFC v2 to (non-RFC) v1 * Clean up issues identified in comments on the pmbus core changes * Define and implement bindings for the MAX31785 * Clean up issues identified in comments on the max31785 driver Andrew Jeffery (4): dt-bindings: hwmon: pmbus: Add Maxim MAX31785 documentation hwmon: pmbus: Add fan control support pmbus: Add driver for Maxim MAX31785 Intelligent Fan Controller pmbus: max31785: Work around back-to-back writes with FAN_CONFIG_1_2 .../devicetree/bindings/hwmon/pmbus/max31785.txt | 126 ++++ drivers/hwmon/pmbus/Kconfig | 10 + drivers/hwmon/pmbus/Makefile | 1 + drivers/hwmon/pmbus/max31785.c | 762 +++++++++++++++++++++ drivers/hwmon/pmbus/pmbus.h | 29 + drivers/hwmon/pmbus/pmbus_core.c | 224 +++++- 6 files changed, 1137 insertions(+), 15 deletions(-) create mode 100644 Documentation/devicetree/bindings/hwmon/pmbus/max31785.txt create mode 100644 drivers/hwmon/pmbus/max31785.c -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
