On Wed, Jul 06, 2016 at 02:04:49PM +0300, Mika Kahola wrote:
> Read DisplayPort branch device id string.
Reviewed-by: Jim Bride <jim.bride at linux.intel.com>
>
> Signed-off-by: Mika Kahola <mika.kahola at intel.com>
> ---
> drivers/gpu/drm/drm_dp_helper.c | 12 ++++++++++++
> include/drm/drm_dp_helper.h | 2 ++
> 2 files changed, 14 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 95d624a..4003464 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -513,6 +513,18 @@ int drm_dp_downstream_max_bpc(const u8
> dpcd[DP_RECEIVER_CAP_SIZE],
> }
> EXPORT_SYMBOL(drm_dp_downstream_max_bpc);
>
> +/**
> + * drm_dp_downstream_id() - identify branch device
> + * @aux: DisplayPort AUX channel
> + *
> + * Returns branch device id on success or NULL on failure
> + */
> +int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6])
> +{
> + return drm_dp_dpcd_read(aux, DP_BRANCH_ID, id, 6);
> +}
> +EXPORT_SYMBOL(drm_dp_downstream_id);
> +
> /*
> * I2C-over-AUX implementation
> */
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index 47ae8ed..8264d54 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -445,6 +445,7 @@
> #define DP_SOURCE_OUI 0x300
> #define DP_SINK_OUI 0x400
> #define DP_BRANCH_OUI 0x500
> +#define DP_BRANCH_ID 0x503
>
> #define DP_SET_POWER 0x600
> # define DP_SET_POWER_D0 0x1
> @@ -810,6 +811,7 @@ int drm_dp_downstream_max_clock(const u8
> dpcd[DP_RECEIVER_CAP_SIZE],
> const u8 port_cap[4]);
> 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]);
>
> void drm_dp_aux_init(struct drm_dp_aux *aux);
> int drm_dp_aux_register(struct drm_dp_aux *aux);
> --
> 1.9.1
