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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: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Dmitry 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: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
This commit is contained in:
Kuogee Hsieh 2022-12-27 09:45:02 -08:00 committed by Dmitry Baryshkov
parent d25cfeeec0
commit 381518a167
2 changed files with 30 additions and 0 deletions
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28
drivers/gpu/drm/msm/dp/dp_parser.c
View File

@ -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;
}

2
drivers/gpu/drm/msm/dp/dp_parser.h
View File

@ -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);