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
Signed-off-by: Kuogee Hsieh <[email protected]>
---
drivers/gpu/drm/msm/dp/dp_parser.c | 27 +++++++++++++++++++++++++++
drivers/gpu/drm/msm/dp/dp_parser.h | 2 ++
2 files changed, 29 insertions(+)
diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c b/drivers/gpu/drm/msm/dp/dp_parser.c
index b5f7e70..5549495 100644
--- a/drivers/gpu/drm/msm/dp/dp_parser.c
+++ b/drivers/gpu/drm/msm/dp/dp_parser.c
@@ -91,6 +91,29 @@ 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 = 0;
+
+ 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);
+
+ frequency /= 10; /* from symbol rate to link rate */
+ frequency /= 1000; /* kbytes */
+
+ return frequency;
+}
+
static int dp_parser_misc(struct dp_parser *parser)
{
struct device_node *of_node = parser->pdev->dev.of_node;
@@ -113,6 +136,10 @@ static int dp_parser_misc(struct dp_parser *parser)
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 866c1a8..526131ee 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);
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
On 13 December 2022 23:44:07 EET, Kuogee Hsieh <[email protected]> wrote:
>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
>
>Signed-off-by: Kuogee Hsieh <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>
>---
> drivers/gpu/drm/msm/dp/dp_parser.c | 27 +++++++++++++++++++++++++++
> drivers/gpu/drm/msm/dp/dp_parser.h | 2 ++
> 2 files changed, 29 insertions(+)
--
With best wishes
Dmitry
Quoting Kuogee Hsieh (2022-12-13 13:44:07)
> Add capability to parser and retrieve max DP link supported rate from
to parse
> 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
>
> Signed-off-by: Kuogee Hsieh <[email protected]>
> ---
Same parser in subject.
> drivers/gpu/drm/msm/dp/dp_parser.c | 27 +++++++++++++++++++++++++++
> drivers/gpu/drm/msm/dp/dp_parser.h | 2 ++
> 2 files changed, 29 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c b/drivers/gpu/drm/msm/dp/dp_parser.c
> index b5f7e70..5549495 100644
> --- a/drivers/gpu/drm/msm/dp/dp_parser.c
> +++ b/drivers/gpu/drm/msm/dp/dp_parser.c
> @@ -91,6 +91,29 @@ 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 = 0;
'cnt' doesn't need to be initialized here.
> +
> + 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);
> +
> + frequency /= 10; /* from symbol rate to link rate */
> + frequency /= 1000; /* kbytes */
Use do_div(frequency, 10 * 1000)? If you want comments it could maybe be
like this:
do_div(frequency,
10 * /* from symbol rate to link rate */
1000); /* kbytes */
> +
> + return frequency;
> +}
> +