Heiko, On Tue, Nov 15, 2016 at 2:38 PM, Heiko Stuebner <heiko at sntech.de> wrote: > The General Register Files are an area of registers containing a lot > of single-bit settings for numerous components as well full components > like usbphy control. Therefore all used components are accessed > via the syscon provided by the grf nodes or from the sub-devices > created through the simple-mfd created from the grf node. > > Some settings are not used by anything but will need to be set up > according to expectations on the kernel side. > > Best example is the force_jtag setting, which defaults to on and > results in the soc switching the pin-outputs between jtag and sdmmc > automatically depending on the card-detect status. This conflicts > heavily with how the dw_mmc driver expects to do its work and also > with the clock-controller, which has most likely deactivated the > jtag clock due to it being unused. > > So far the handling of this setting was living in the mach-rockchip > code for the arm32-based rk3288 but that of course doesn't work > for arm64 socs and would also look ugly for further arm32 socs. > > Also always disabling this setting is quite specific to linux and > its subsystems, other operating systems might prefer other settings, > so that the bootloader cannot really set a sane default for all. > > So introduce a top-level driver for the grf that handles these > settings that need to be a certain way but nobody cares about. > > Other needed settings might surface in the future and can then > be added here, but only as a last option. Ideally general GRF > settings should be handled in the driver needing them. > > Signed-off-by: Heiko Stuebner <heiko at sntech.de> > --- > drivers/soc/rockchip/Kconfig | 10 ++++ > drivers/soc/rockchip/Makefile | 1 + > drivers/soc/rockchip/grf.c | 134 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 145 insertions(+) Other than the header file stuff pointed out by Shawn, this looks good to me now. Reviewed-by: Douglas Anderson <dianders at chromium.org>
