Re: [PATCH v3] drm/dsc: Add kernel documentation for DRM DP DSC helpers
Pushed to drm-misc thanks for the reviews.
Regards
Manasi
On Wed, Feb 06, 2019 at 01:31:48PM -0800, Manasi Navare wrote:
> This patch adds appropriate kernel documentation for DRM DP helpers
> used for enabling Display Stream compression functionality in
> drm_dp_helper.h and drm_dp_helper.c as well as for the DSC spec
> related structure definitions and helpers in drm_dsc.c and drm_dsc.h
> Also add links between the functions and structures in the documentation.
>
> v3:
> * Fix the checkpatch warnings (Sean Paul)
> v2:
> * Add inline comments for longer structs (Daniel Vetter)
> * Split the summary and description (Daniel Vetter)
>
> Suggested-by: Daniel Vetter
> Suggested-by: Sean Paul
> Cc: Daniel Vetter
> Cc: Sean Paul
> Signed-off-by: Manasi Navare
> Acked-by: Sean Paul
> Reviewed-by: Daniel Vetter
> ---
> drivers/gpu/drm/drm_dp_helper.c | 47 ++-
> drivers/gpu/drm/drm_dsc.c | 30 +++-
> include/drm/drm_dp_helper.h | 15 +-
> include/drm/drm_dsc.h | 233
> 4 files changed, 259 insertions(+), 66 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 54120b6319e7..54a6414c5d96 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -1360,7 +1360,20 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct
> drm_dp_desc *desc,
> EXPORT_SYMBOL(drm_dp_read_desc);
>
> /**
> - * DRM DP Helpers for DSC
> + * drm_dp_dsc_sink_max_slice_count() - Get the max slice count
> + * supported by the DSC sink.
> + * @dsc_dpcd: DSC capabilities from DPCD
> + * @is_edp: true if its eDP, false for DP
> + *
> + * Read the slice capabilities DPCD register from DSC sink to get
> + * the maximum slice count supported. This is used to populate
> + * the DSC parameters in the drm_dsc_config by the driver.
> + * Driver creates an infoframe using these parameters to populate
> + * drm_dsc_pps_infoframe. These are sent to the sink using DSC
> + * infoframe using the helper function drm_dsc_pps_infoframe_pack()
> + *
> + * Returns:
> + * Maximum slice count supported by DSC sink or 0 its invalid
> */
> u8 drm_dp_dsc_sink_max_slice_count(const u8
> dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
> bool is_edp)
> @@ -1405,6 +1418,21 @@ u8 drm_dp_dsc_sink_max_slice_count(const u8
> dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
> }
> EXPORT_SYMBOL(drm_dp_dsc_sink_max_slice_count);
>
> +/**
> + * drm_dp_dsc_sink_line_buf_depth() - Get the line buffer depth in bits
> + * @dsc_dpcd: DSC capabilities from DPCD
> + *
> + * Read the DSC DPCD register to parse the line buffer depth in bits which is
> + * number of bits of precision within the decoder line buffer supported by
> + * the DSC sink. This is used to populate the DSC parameters in the
> + * drm_dsc_config by the driver.
> + * Driver creates an infoframe using these parameters to populate
> + * drm_dsc_pps_infoframe. These are sent to the sink using DSC
> + * infoframe using the helper function drm_dsc_pps_infoframe_pack()
> + *
> + * Returns:
> + * Line buffer depth supported by DSC panel or 0 its invalid
> + */
> u8 drm_dp_dsc_sink_line_buf_depth(const u8
> dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
> {
> u8 line_buf_depth = dsc_dpcd[DP_DSC_LINE_BUF_BIT_DEPTH -
> DP_DSC_SUPPORT];
> @@ -1434,6 +1462,23 @@ u8 drm_dp_dsc_sink_line_buf_depth(const u8
> dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
> }
> EXPORT_SYMBOL(drm_dp_dsc_sink_line_buf_depth);
>
> +/**
> + * drm_dp_dsc_sink_supported_input_bpcs() - Get all the input bits per
> component
> + * values supported by the DSC sink.
> + * @dsc_dpcd: DSC capabilities from DPCD
> + * @dsc_bpc: An array to be filled by this helper with supported
> + * input bpcs.
> + *
> + * Read the DSC DPCD from the sink device to parse the supported bits per
> + * component values. This is used to populate the DSC parameters
> + * in the drm_dsc_config by the driver.
> + * Driver creates an infoframe using these parameters to populate
> + * drm_dsc_pps_infoframe. These are sent to the sink using DSC
> + * infoframe using the helper function drm_dsc_pps_infoframe_pack()
> + *
> + * Returns:
> + * Number of input BPC values parsed from the DPCD
> + */
> int drm_dp_dsc_sink_supported_input_bpcs(const u8
> dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
>u8 dsc_bpc[3])
> {
> diff --git a/drivers/gpu/drm/drm_dsc.c b/drivers/gpu/drm/drm_dsc.c
> index bc2b23adb072..bce99f95c1a3 100644
> --- a/drivers/gpu/drm/drm_dsc.c
> +++ b/drivers/gpu/drm/drm_dsc.c
> @@ -17,6 +17,12 @@
> /**
> * DOC: dsc helpers
> *
> + * VESA specification for DP 1.4 adds a new feature called Display Stream
> + * Compression (DSC) used to compress the pixel bits before sending it on
> + * DP/eDP/MIPI DSI interface. DSC is required to be enabled so that the
> existing
> + * display interfaces can support high resolutions at higher frames rates
> uisng
> + * the
[PATCH v3] drm/dsc: Add kernel documentation for DRM DP DSC helpers
This patch adds appropriate kernel documentation for DRM DP helpers
used for enabling Display Stream compression functionality in
drm_dp_helper.h and drm_dp_helper.c as well as for the DSC spec
related structure definitions and helpers in drm_dsc.c and drm_dsc.h
Also add links between the functions and structures in the documentation.
v3:
* Fix the checkpatch warnings (Sean Paul)
v2:
* Add inline comments for longer structs (Daniel Vetter)
* Split the summary and description (Daniel Vetter)
Suggested-by: Daniel Vetter
Suggested-by: Sean Paul
Cc: Daniel Vetter
Cc: Sean Paul
Signed-off-by: Manasi Navare
Acked-by: Sean Paul
Reviewed-by: Daniel Vetter
---
drivers/gpu/drm/drm_dp_helper.c | 47 ++-
drivers/gpu/drm/drm_dsc.c | 30 +++-
include/drm/drm_dp_helper.h | 15 +-
include/drm/drm_dsc.h | 233
4 files changed, 259 insertions(+), 66 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 54120b6319e7..54a6414c5d96 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -1360,7 +1360,20 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct
drm_dp_desc *desc,
EXPORT_SYMBOL(drm_dp_read_desc);
/**
- * DRM DP Helpers for DSC
+ * drm_dp_dsc_sink_max_slice_count() - Get the max slice count
+ * supported by the DSC sink.
+ * @dsc_dpcd: DSC capabilities from DPCD
+ * @is_edp: true if its eDP, false for DP
+ *
+ * Read the slice capabilities DPCD register from DSC sink to get
+ * the maximum slice count supported. This is used to populate
+ * the DSC parameters in the drm_dsc_config by the driver.
+ * Driver creates an infoframe using these parameters to populate
+ * drm_dsc_pps_infoframe. These are sent to the sink using DSC
+ * infoframe using the helper function drm_dsc_pps_infoframe_pack()
+ *
+ * Returns:
+ * Maximum slice count supported by DSC sink or 0 its invalid
*/
u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
bool is_edp)
@@ -1405,6 +1418,21 @@ u8 drm_dp_dsc_sink_max_slice_count(const u8
dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
}
EXPORT_SYMBOL(drm_dp_dsc_sink_max_slice_count);
+/**
+ * drm_dp_dsc_sink_line_buf_depth() - Get the line buffer depth in bits
+ * @dsc_dpcd: DSC capabilities from DPCD
+ *
+ * Read the DSC DPCD register to parse the line buffer depth in bits which is
+ * number of bits of precision within the decoder line buffer supported by
+ * the DSC sink. This is used to populate the DSC parameters in the
+ * drm_dsc_config by the driver.
+ * Driver creates an infoframe using these parameters to populate
+ * drm_dsc_pps_infoframe. These are sent to the sink using DSC
+ * infoframe using the helper function drm_dsc_pps_infoframe_pack()
+ *
+ * Returns:
+ * Line buffer depth supported by DSC panel or 0 its invalid
+ */
u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
{
u8 line_buf_depth = dsc_dpcd[DP_DSC_LINE_BUF_BIT_DEPTH -
DP_DSC_SUPPORT];
@@ -1434,6 +1462,23 @@ u8 drm_dp_dsc_sink_line_buf_depth(const u8
dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
}
EXPORT_SYMBOL(drm_dp_dsc_sink_line_buf_depth);
+/**
+ * drm_dp_dsc_sink_supported_input_bpcs() - Get all the input bits per
component
+ * values supported by the DSC sink.
+ * @dsc_dpcd: DSC capabilities from DPCD
+ * @dsc_bpc: An array to be filled by this helper with supported
+ * input bpcs.
+ *
+ * Read the DSC DPCD from the sink device to parse the supported bits per
+ * component values. This is used to populate the DSC parameters
+ * in the drm_dsc_config by the driver.
+ * Driver creates an infoframe using these parameters to populate
+ * drm_dsc_pps_infoframe. These are sent to the sink using DSC
+ * infoframe using the helper function drm_dsc_pps_infoframe_pack()
+ *
+ * Returns:
+ * Number of input BPC values parsed from the DPCD
+ */
int drm_dp_dsc_sink_supported_input_bpcs(const u8
dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
u8 dsc_bpc[3])
{
diff --git a/drivers/gpu/drm/drm_dsc.c b/drivers/gpu/drm/drm_dsc.c
index bc2b23adb072..bce99f95c1a3 100644
--- a/drivers/gpu/drm/drm_dsc.c
+++ b/drivers/gpu/drm/drm_dsc.c
@@ -17,6 +17,12 @@
/**
* DOC: dsc helpers
*
+ * VESA specification for DP 1.4 adds a new feature called Display Stream
+ * Compression (DSC) used to compress the pixel bits before sending it on
+ * DP/eDP/MIPI DSI interface. DSC is required to be enabled so that the
existing
+ * display interfaces can support high resolutions at higher frames rates uisng
+ * the maximum available link capacity of these interfaces.
+ *
* These functions contain some common logic and helpers to deal with VESA
* Display Stream Compression standard required for DSC on Display Port/eDP or
* MIPI display interfaces.
@@ -26,6 +32,13 @@
* drm_dsc_dp_pps_header_init() - Initializes the PPS Header
* for DisplayPort as per the DP 1.4
