From 381518a1677c49742a85f51e8f0e89f4b9b7d297 Mon Sep 17 00:00:00 2001 From: Kuogee Hsieh Date: Tue, 27 Dec 2022 09:45:02 -0800 Subject: [PATCH] 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 Reviewed-by: Dmitry Baryshkov 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 --- drivers/gpu/drm/msm/dp/dp_parser.c | 28 ++++++++++++++++++++++++++++ drivers/gpu/drm/msm/dp/dp_parser.h | 2 ++ 2 files changed, 30 insertions(+) diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c b/drivers/gpu/drm/msm/dp/dp_parser.c index 169023e..7032dcc 100644 --- a/drivers/gpu/drm/msm/dp/dp_parser.c +++ b/drivers/gpu/drm/msm/dp/dp_parser.c @@ -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; } diff --git a/drivers/gpu/drm/msm/dp/dp_parser.h b/drivers/gpu/drm/msm/dp/dp_parser.h index d30ab77..1f068626 100644 --- a/drivers/gpu/drm/msm/dp/dp_parser.h +++ b/drivers/gpu/drm/msm/dp/dp_parser.h @@ -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); -- 2.7.4