Commit 381518a1 authored by Kuogee Hsieh's avatar Kuogee Hsieh Committed by Dmitry Baryshkov
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drm/msm/dp: Add capability to parser and retrieve max DP link supported rate... 


drm/msm/dp: Add capability to parser and retrieve max DP link supported rate from link-frequencies property of dp_out endpoint

Changes in v6:
-- second patch after split parser patch into two patches

Changes in v7:
-- without checking cnt against DP_MAX_NUM_DP_LANES to retrieve link rate

Changes in v9:
-- separate parser link-frequencies out of data-lanes

Changes in v10:
-- add dp_parser_link_frequencies()

Changes in v11:
-- return 0 if(!endpoint)

Changes in v12:
-- replace khz with kbytes at dp_parser.h

Changes in v14:
-- replace "parser" with "parse" at commit subject
-- use do_div() for 64 bits division

Signed-off-by: default avatarKuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/516100/
Link: https://lore.kernel.org/r/1672163103-31254-5-git-send-email-quic_khsieh@quicinc.com


Signed-off-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
parent d25cfeee

drivers/gpu/drm/msm/dp/dp_parser.c

+28 −0
Original line number Diff line number Diff line
@@ -91,6 +91,30 @@ static int dp_parser_ctrl_res(struct dp_parser *parser) 
	return 0;

}



static u32 dp_parser_link_frequencies(struct device_node *of_node)

{

	struct device_node *endpoint;

	u64 frequency = 0;

	int cnt;



	endpoint = of_graph_get_endpoint_by_regs(of_node, 1, 0); /* port@1 */

	if (!endpoint)

		return 0;



	cnt = of_property_count_u64_elems(endpoint, "link-frequencies");



	if (cnt > 0)

		of_property_read_u64_index(endpoint, "link-frequencies",

						cnt - 1, &frequency);

	of_node_put(endpoint);



	do_div(frequency,

		10 * /* from symbol rate to link rate */

		1000); /* kbytes */



	return frequency;

}



static int dp_parser_misc(struct dp_parser *parser)

{

	struct device_node *of_node = parser->pdev->dev.of_node;
@@ -110,6 +134,10 @@ static int dp_parser_misc(struct dp_parser *parser) 
	else

		parser->max_dp_lanes = DP_MAX_NUM_DP_LANES; /* 4 lanes */



	parser->max_dp_link_rate = dp_parser_link_frequencies(of_node);

	if (!parser->max_dp_link_rate)

		parser->max_dp_link_rate = DP_LINK_RATE_HBR2;



	return 0;

}

drivers/gpu/drm/msm/dp/dp_parser.h

+2 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#define DP_LABEL "MDSS DP DISPLAY"

#define DP_MAX_PIXEL_CLK_KHZ	675000

#define DP_MAX_NUM_DP_LANES	4

#define DP_LINK_RATE_HBR2	540000 /* kbytes */



enum dp_pm_type {

	DP_CORE_PM,
@@ -119,6 +120,7 @@ struct dp_parser { 
	struct dp_io io;

	struct dp_display_data disp_data;

	u32 max_dp_lanes;

	u32 max_dp_link_rate;

	struct drm_bridge *next_bridge;



	int (*parse)(struct dp_parser *parser);