drm/display/dp: Add helper function to get DSC bpp precision

Add helper to get the DSC bits_per_pixel precision for the DP sink.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231110101020.4067342-2-ankit.k.nautiyal@intel.com

diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
index 64c151e4f78ca39d84d53527017604556fa1bf88..ff8d67d0e9dc9c2a117c32a41056d0565cd75b68 100644 (file)
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -2325,6 +2325,33 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
 }
 EXPORT_SYMBOL(drm_dp_read_desc);
 
+/**
+ * drm_dp_dsc_sink_bpp_incr() - Get bits per pixel increment
+ * @dsc_dpcd: DSC capabilities from DPCD
+ *
+ * Returns the bpp precision supported by the DP sink.
+ */
+u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
+{
+       u8 bpp_increment_dpcd = dsc_dpcd[DP_DSC_BITS_PER_PIXEL_INC - DP_DSC_SUPPORT];
+
+       switch (bpp_increment_dpcd) {
+       case DP_DSC_BITS_PER_PIXEL_1_16:
+               return 16;
+       case DP_DSC_BITS_PER_PIXEL_1_8:
+               return 8;
+       case DP_DSC_BITS_PER_PIXEL_1_4:
+               return 4;
+       case DP_DSC_BITS_PER_PIXEL_1_2:
+               return 2;
+       case DP_DSC_BITS_PER_PIXEL_1_1:
+               return 1;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(drm_dp_dsc_sink_bpp_incr);
+
 /**
  * drm_dp_dsc_sink_max_slice_count() - Get the max slice count
  * supported by the DSC sink.

diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h
index 3c59f64d4a691ad47aa2d2774d8a9a4c2ad9187f..194715083399ef11f254b89de7165a4cf8f8d471 100644 (file)
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -164,6 +164,7 @@ drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 }
 
 /* DP/eDP DSC support */
+u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
 u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
                                   bool is_edp);
 u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);