On Fri, Oct 26, 2018 at 09:36:57AM -0700, Ajay Gupta wrote: > Hi Heikki and Wolfram, > > These two changes add support for USB Type-C interface on latest NVIDIA GPU card. > The Type-C controller used is Cypress CCGx and is over I2C interface. > > I2C host controller has known limitation of sending STOP after every read. Since > each read can be of 4 byte maximum length so there is a limit of 4 byte read. > This is mentioned in adapter quirks as "max_read_len = 4" > > I2C host controller is mainly used for "write-then-read" or "write" messages so added > the flag I2C_AQ_COMB_WRITE_THEN_READ in adapter quirks. > > PATCH[2/2] on ucsi driver now have added logic to check i2c adapter quirks and > issues i2c read transfer based on max_read_len quirk settings. This will make sure > the read limitation is not affecting I2C host which do not have such limitation. > > I think the patches should through usb tree because the main functionality is > usb Type-C. FWIW, Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > Thanks > Ajay > > Ajay Gupta (2): > i2c: buses: add i2c bus driver for NVIDIA GPU > usb: typec: ucsi: add support for Cypress CCGx > > Documentation/i2c/busses/i2c-nvidia-gpu | 18 ++ > MAINTAINERS | 7 + > drivers/i2c/busses/Kconfig | 9 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-nvidia-gpu.c | 368 ++++++++++++++++++++++++ > drivers/usb/typec/ucsi/Kconfig | 10 + > drivers/usb/typec/ucsi/Makefile | 2 + > drivers/usb/typec/ucsi/ucsi_ccg.c | 307 ++++++++++++++++++++ > 8 files changed, 722 insertions(+) > create mode 100644 Documentation/i2c/busses/i2c-nvidia-gpu > create mode 100644 drivers/i2c/busses/i2c-nvidia-gpu.c > create mode 100644 drivers/usb/typec/ucsi/ucsi_ccg.c > > -- > 2.17.1 > -- With Best Regards, Andy Shevchenko
