Hi Heikki and Wolfram These patches add support for runtime power management for UCSI CCGx driver. I have tested them with NVIDIA GPU card which has i2c interface to talk to CCG controller. I have added runtime pm support for the i2c bus driver as well. Third version (v4) of patches fix comments from Wolfram on further refactoring master_xfer() fucntion in i2c-nvidia-gpuc.c file. Also I have added comment on why we need a stub gpu_i2c_suspend() for runtime pm to work correctly. First patch refactors master_xfer() of i2c driver fixing comment from Wolfram. Second and third patch add support for runtime pm in i2c bus driver and UCSI CCGx driver. Last two patches add workaround for an old version of ccg firmware which has known issue of missing interrupt when a device is connected to runtime resume the ccg controller. The workaround is needed because if a GPU card doesn't get new firmware but gets new kernel then also it should continue to work. The workaround is to request runtime resume of i2c client which is UCSI Cypress CCGx driver. CCG driver will call the ISR for any connector change event only if NVIDIA GPU has old CCG firmware with the known issue. All the five patches should go together since ucsi_ccg driver is dependent on i2c driver for runtime pm wokaround. I would prefer it to go through usb-tree since usb ucsi_ccg driver is the main driver getting runtime pm functionality with the series. Thanks Ajay Ajay Gupta (5): i2c: nvidia-gpu: refactor master_xfer i2c: nvidia-gpu: add runtime pm support usb: typec: ucsi: ccg: enable runtime pm support i2c: nvidia-gpu: resume ccgx i2c client usb: typec: ucsi: ccg: add runtime pm workaround drivers/i2c/busses/i2c-nvidia-gpu.c | 71 +++++++++++++---- drivers/usb/typec/ucsi/ucsi.c | 10 +++ drivers/usb/typec/ucsi/ucsi.h | 1 + drivers/usb/typec/ucsi/ucsi_ccg.c | 118 +++++++++++++++++++++++++++- 4 files changed, 179 insertions(+), 21 deletions(-) -- 2.17.1
