Hi Guenter, > Guenter Roeck <[email protected]> hat am 2. September 2018 um 18:49 > geschrieben: > > > On 09/02/2018 09:26 AM, Stefan Wahren wrote: > > Hi Guenter, > > > >> Guenter Roeck <[email protected]> hat am 2. September 2018 um 16:23 > >> geschrieben: > >> > >> > >> On 09/02/2018 04:20 AM, Stefan Wahren wrote: > >>> This series is an early stage of the hwmon driver for the fan on the > >>> Raspberry Pi Power over Ethernet HAT [1]. At the end this should use a > >>> Device Tree Overlay. > >>> > >>> Changes by Stefan based on [2]: > >>> - reformat the downstream patches for submission > >>> - drop reboot notification > >>> - fix remaining checkpatch issues > >>> - add COMPILE_TEST to Kconfig > >>> > >>> The driver is mostly copy & paste from pwm-fan, which isn't good. > >>> Personally > >>> i see two options: > >>> > >>> 1) integrate the driver function into the pwm-fan driver (new compatible) > >>> 2) implement the core function as a PWM driver and use the pwm-fan driver > >>> on top > >>> > >> > >> I don't really see the point of thise driver. Why not implement either of > >> those ? > > > > i'm not sure about your question. Since the fan is placed over the SoC, the > > fan should takes care of the SoC temperature. AFAIK the firmware should > > have exclusive access to the I2C. So why we need this mailbox interface > > instead of a I2C driver. > > > > The driver sets pwm values. The pwm-fan driver sets pwm values. A pwm driver > sets pwm values. The pwm-fan driver uses a pwm driver to set pwm values. > You appear to be arguing that the pwm-fan driver for Rpi is different than > a pwm-fan driver for all other hardware and should _not_ use a pwm driver > to set pwm values.
thanks for your explanation. Now i think i understand and sorry for the confusion. We need a driver which translate the pwm values into the mailbox properties. "My" RFC series is only a starting point (not intended for merge and not an option) for a discussion and i'm perfectly fine with 2). Both options would be feasible in general. I only wanted to know your opinion before i start to implement one of them. Stefan > > As you don't understand my question, I don't understand your rationale either. > I will require detailed explanations why 2) is not feasible, and why 1) is not > feasible either. Until then, NACK. > > Guenter > > >> 2) sounds like a perfect fit to me. > >> > >> Guenter > >> > >>> [1] - https://www.raspberrypi.org/products/poe-hat/ > >>> [2] - > >>> https://github.com/raspberrypi/linux/commit/0f937c8dc3201ebffa6c617c616fd7c65db65959 > >>> > >>> Serge Schneider (2): > >>> dt-bindings: hwmon: Add RPi PoE HAT documentation > >>> hwmon: Add RPi PoE HAT fan driver > >>> > >>> .../devicetree/bindings/hwmon/rpi-poe-fan.txt | 55 +++ > >>> Documentation/hwmon/rpi-poe-fan | 15 + > >>> drivers/hwmon/Kconfig | 11 + > >>> drivers/hwmon/Makefile | 1 + > >>> drivers/hwmon/rpi-poe-fan.c | 414 > >>> +++++++++++++++++++++ > >>> include/soc/bcm2835/raspberrypi-firmware.h | 2 + > >>> 6 files changed, 498 insertions(+) > >>> create mode 100644 > >>> Documentation/devicetree/bindings/hwmon/rpi-poe-fan.txt > >>> create mode 100644 Documentation/hwmon/rpi-poe-fan > >>> create mode 100644 drivers/hwmon/rpi-poe-fan.c > >>> > >> > > > > > _______________________________________________ > linux-arm-kernel mailing list > [email protected] > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
