On Wed, Jul 06, 2016 at 02:04:50PM +0300, Mika Kahola wrote: > HW revision is mandatory field for DisplayPort branch > devices. This is defined in DPCD register field 0x509. > > Signed-off-by: Mika Kahola <mika.kahola@xxxxxxxxx> > --- > drivers/gpu/drm/drm_dp_helper.c | 21 +++++++++++++++++++++ > include/drm/drm_dp_helper.h | 7 +++++++ > 2 files changed, 28 insertions(+) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index 4003464..cfd75df 100644 > --- a/drivers/gpu/drm/drm_dp_helper.c > +++ b/drivers/gpu/drm/drm_dp_helper.c > @@ -514,6 +514,27 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], > EXPORT_SYMBOL(drm_dp_downstream_max_bpc); > > /** > + * drm_dp_downstream_hw_rev() - read DP branch device HW revision > + * @aux: DisplayPort AUX channel > + * > + * Returns HW revision on succes or negative error code on failure > + */ > +struct drm_dp_revision drm_dp_downstream_hw_rev(struct drm_dp_aux *aux) > +{ > + uint8_t tmp; > + struct drm_dp_revision rev = { .major = -EINVAL, .minor = -EINVAL }; > + > + if (drm_dp_dpcd_read(aux, DP_BRANCH_HW_REV, &tmp, 1) != 1) > + return rev; > + > + rev.major = (tmp & 0xf0) >> 4; > + rev.minor = tmp & 0xf; > + > + return rev; > +} > +EXPORT_SYMBOL(drm_dp_downstream_hw_rev); > + > +/** > * drm_dp_downstream_id() - identify branch device > * @aux: DisplayPort AUX channel > * > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h > index 8264d54..5f577e4 100644 > --- a/include/drm/drm_dp_helper.h > +++ b/include/drm/drm_dp_helper.h > @@ -446,6 +446,7 @@ > #define DP_SINK_OUI 0x400 > #define DP_BRANCH_OUI 0x500 > #define DP_BRANCH_ID 0x503 > +#define DP_BRANCH_HW_REV 0x509 > > #define DP_SET_POWER 0x600 > # define DP_SET_POWER_D0 0x1 > @@ -803,6 +804,11 @@ struct drm_dp_link { > unsigned long capabilities; > }; > > +struct drm_dp_revision { > + int major; > + int minor; > +}; Atm we have two styles of helpers: - The ones that put decoded values into struct drm_dp_link - A pile of functions that return individual values. This seems to add a third one. I guess it'd be better to just move everything over to putting parsed values into drm_dp_link and fill that out for everything ... -Daniel > + > int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link); > int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link); > int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link); > @@ -812,6 +818,7 @@ int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], > int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], > const u8 port_cap[4]); > int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]); > +struct drm_dp_revision drm_dp_downstream_hw_rev(struct drm_dp_aux *aux); > > void drm_dp_aux_init(struct drm_dp_aux *aux); > int drm_dp_aux_register(struct drm_dp_aux *aux); > -- > 1.9.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel