On Mon, 2018-02-19 at 17:54 +1030, Joel Stanley wrote: > To date this driver has relied on prevous state from out of tree hacks > and vendor u-boot trees in order to have the host be able to access > data over the LPC bus. > > Now we explicitly enable the AHB to LPC bridge and FWH cycles from when > the user first configures the address to map. We chose to do this then > as before that time there is no way for the kernel to know where it is > safe to point the LPC window. > > Tested-by: Lei YU <mine260...@gmail.com> > Reviewed-by: Andrew Jeffery <and...@aj.id.au> > Signed-off-by: Joel Stanley <j...@jms.id.au>
Reviewed-by: Cyril Bur <cyril...@gmail.com> > --- > drivers/misc/aspeed-lpc-ctrl.c | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/drivers/misc/aspeed-lpc-ctrl.c b/drivers/misc/aspeed-lpc-ctrl.c > index 1827b7aa6674..a024f8042259 100644 > --- a/drivers/misc/aspeed-lpc-ctrl.c > +++ b/drivers/misc/aspeed-lpc-ctrl.c > @@ -21,6 +21,10 @@ > > #define DEVICE_NAME "aspeed-lpc-ctrl" > > +#define HICR5 0x0 > +#define HICR5_ENL2H BIT(8) > +#define HICR5_ENFWH BIT(10) > + > #define HICR7 0x8 > #define HICR8 0xc > > @@ -155,8 +159,18 @@ static long aspeed_lpc_ctrl_ioctl(struct file *file, > unsigned int cmd, > if (rc) > return rc; > > - return regmap_write(lpc_ctrl->regmap, HICR8, > - (~(map.size - 1)) | ((map.size >> 16) - 1)); > + rc = regmap_write(lpc_ctrl->regmap, HICR8, > + (~(map.size - 1)) | ((map.size >> 16) - 1)); > + if (rc) > + return rc; > + > + /* > + * Enable LPC FHW cycles. This is required for the host to > + * access the regions specified. > + */ > + return regmap_update_bits(lpc_ctrl->regmap, HICR5, > + HICR5_ENFWH | HICR5_ENL2H, > + HICR5_ENFWH | HICR5_ENL2H); > } > > return -EINVAL;
