diff options
| author | Thierry Reding <treding@nvidia.com> | 2013-11-22 16:37:57 +0100 |
|---|---|---|
| committer | Thierry Reding <treding@nvidia.com> | 2014-01-10 10:15:22 +0100 |
| commit | 962b70e2334340dbe6718692f6953e8910dbb4ad (patch) | |
| tree | eec7bd5672fed2c2d482a5e7eadc2f7ce6398efb | |
| parent | 39557004048ae6a8313c6ea17695670e543f9987 (diff) | |
drm/dp: Add drm_dp_dpcd_read_link_status()
The function reads the link status (6 bytes starting at offset 0x202)
from the DPCD so that it can be conveniently passed to other DPCD
helpers.
Signed-off-by: Thierry Reding <treding@nvidia.com>
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 16 | ||||
| -rw-r--r-- | include/drm/drm_dp_helper.h | 3 |
2 files changed, 19 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 3641c5eb349b..572637456713 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -456,3 +456,19 @@ ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, size); } EXPORT_SYMBOL(drm_dp_dpcd_write); + +/** + * drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207) + * @aux: DisplayPort AUX channel + * @status: buffer to store the link status in (must be at least 6 bytes) + * + * Returns the number of bytes transferred on success or a negative error + * code on failure. + */ +int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, + u8 status[DP_LINK_STATUS_SIZE]) +{ + return drm_dp_dpcd_read(aux, DP_LANE0_1_STATUS, status, + DP_LINK_STATUS_SIZE); +} +EXPORT_SYMBOL(drm_dp_dpcd_read_link_status); diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 1cd9e84ee0af..f6c61f3178f8 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -465,4 +465,7 @@ static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux, u8 value, return drm_dp_dpcd_write(aux, offset, &value, 1); } +int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, + u8 status[DP_LINK_STATUS_SIZE]); + #endif /* _DRM_DP_HELPER_H_ */ |