[PATCH v3 0/2] *** IT6505 driver read dt properties ***

[PATCH v3 0/2] *** IT6505 driver read dt properties ***

[allen]

From: allen chen <allen.chen@ite.com.tw>

This series let driver can read properties from dt to restrict dp output
bandwidth.

Changes in v3:
-Rename property name.

allen chen (2):
  dt-bindings: it6505: add properties to restrict output bandwidth
  drm/bridge: add it6505 driver to read data-lanes and
    max-pixel-clock-mhz from dt

 .../bindings/display/bridge/ite,it6505.yaml   | 12 +++++++
 drivers/gpu/drm/bridge/ite-it6505.c           | 36 +++++++++++++++++--
 2 files changed, 45 insertions(+), 3 deletions(-)

-- 
2.25.1

[PATCH v3 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

[allen]

From: allen chen <allen.chen@ite.com.tw>

Add properties to restrict dp output data-lanes and clock.

Signed-off-by: Pin-Yen Lin <treapking@chromium.org>
Signed-off-by: Allen Chen <allen.chen@ite.com.tw>
---
 .../bindings/display/bridge/ite,it6505.yaml          | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
index 833d11b2303a..f5482a614d05 100644
--- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
@@ -52,6 +52,16 @@ properties:
     maxItems: 1
     description: extcon specifier for the Power Delivery
 
+  ite,dp-output-data-lane-count:
+    description: restrict the dp output data-lanes with value of 1-4
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [ 1, 2, 4 ]
+
+  ite,dp-output-max-pixel-clock-mhz:
+    description: restrict max pixel clock
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 150
+
   port:
     $ref: /schemas/graph.yaml#/properties/port
     description: A port node pointing to DPI host port node
@@ -84,6 +94,8 @@ examples:
             pwr18-supply = <&it6505_pp18_reg>;
             reset-gpios = <&pio 179 1>;
             extcon = <&usbc_extcon>;
+            ite,dp-output-data-lane-count = <2>;
+            ite,dp-output-max-pixel-clock-mhz = <150>;
 
             port {
                 it6505_in: endpoint {
-- 
2.25.1

Re: [PATCH v3 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

[Krzysztof Kozlowski]

On 06/10/2022 04:04, allen wrote:
> From: allen chen <allen.chen@ite.com.tw>
> 
> Add properties to restrict dp output data-lanes and clock.
> 
> Signed-off-by: Pin-Yen Lin <treapking@chromium.org>
> Signed-off-by: Allen Chen <allen.chen@ite.com.tw>
> ---
>  .../bindings/display/bridge/ite,it6505.yaml          | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> index 833d11b2303a..f5482a614d05 100644
> --- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> @@ -52,6 +52,16 @@ properties:
>      maxItems: 1
>      description: extcon specifier for the Power Delivery
>  
> +  ite,dp-output-data-lane-count:
> +    description: restrict the dp output data-lanes with value of 1-4

Drop "with value of 1-4" because it is redundant, but instead explain
what this property is about. "Restrict output" is not yet enough.
Restrict the number? Or choose specific lanes? Why it cannot be
data-lanes from video-interfaces?

> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    enum: [ 1, 2, 4 ]
> +
> +  ite,dp-output-max-pixel-clock-mhz:

Test your patches before sending.

Best regards,
Krzysztof

RE: [PATCH v3 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

[allen.chen]

hi

-----Original Message-----
From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> 
Sent: Thursday, October 6, 2022 4:17 PM
To: Allen Chen (陳柏宇) <allen.chen@ite.com.tw>
Cc: Jau-Chih Tseng (曾昭智) <Jau-Chih.Tseng@ite.com.tw>; Kenneth Hung (洪家倫) <Kenneth.Hung@ite.com.tw>; Hermes Wu (吳佳宏) <Hermes.Wu@ite.com.tw>; Pin-yen Lin <treapking@chromium.org>; Andrzej Hajda <andrzej.hajda@intel.com>; Neil Armstrong <narmstrong@baylibre.com>; Robert Foss <robert.foss@linaro.org>; Laurent Pinchart <Laurent.pinchart@ideasonboard.com>; Jonas Karlman <jonas@kwiboo.se>; Jernej Skrabec <jernej.skrabec@gmail.com>; David Airlie <airlied@linux.ie>; Daniel Vetter <daniel@ffwll.ch>; Rob Herring <robh+dt@kernel.org>; Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>; open list:DRM DRIVERS <dri-devel@lists.freedesktop.org>; open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS <devicetree@vger.kernel.org>; open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

On 06/10/2022 04:04, allen wrote:
> From: allen chen <allen.chen@ite.com.tw>
> 
> Add properties to restrict dp output data-lanes and clock.
> 
> Signed-off-by: Pin-Yen Lin <treapking@chromium.org>
> Signed-off-by: Allen Chen <allen.chen@ite.com.tw>
> ---
>  .../bindings/display/bridge/ite,it6505.yaml          | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git 
> a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml 
> b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> index 833d11b2303a..f5482a614d05 100644
> --- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> @@ -52,6 +52,16 @@ properties:
>      maxItems: 1
>      description: extcon specifier for the Power Delivery
>  
> +  ite,dp-output-data-lane-count:
> +    description: restrict the dp output data-lanes with value of 1-4

Drop "with value of 1-4" because it is redundant, but instead explain what this property is about. "Restrict output" is not yet enough.
Restrict the number? Or choose specific lanes? Why it cannot be data-lanes from video-interfaces?

==> DP output bandwidth depends on data-lane-count, so the number of output data-lane-count will restrict output bandwidth.
In this dt-binding we don't have output endpoint, so use another property name to configure.
If need to use data-lanes, where can we put in this dt-binding?

> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    enum: [ 1, 2, 4 ]
> +
> +  ite,dp-output-max-pixel-clock-mhz:

Test your patches before sending.

Best regards,
Krzysztof

Re: [PATCH v3 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

[Krzysztof Kozlowski]

On 07/10/2022 05:18, allen.chen@ite.com.tw wrote:
> hi
> 
> -----Original Message-----
> From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> 
> Sent: Thursday, October 6, 2022 4:17 PM
> To: Allen Chen (陳柏宇) <allen.chen@ite.com.tw>
> Cc: Jau-Chih Tseng (曾昭智) <Jau-Chih.Tseng@ite.com.tw>; Kenneth Hung (洪家倫) <Kenneth.Hung@ite.com.tw>; Hermes Wu (吳佳宏) <Hermes.Wu@ite.com.tw>; Pin-yen Lin <treapking@chromium.org>; Andrzej Hajda <andrzej.hajda@intel.com>; Neil Armstrong <narmstrong@baylibre.com>; Robert Foss <robert.foss@linaro.org>; Laurent Pinchart <Laurent.pinchart@ideasonboard.com>; Jonas Karlman <jonas@kwiboo.se>; Jernej Skrabec <jernej.skrabec@gmail.com>; David Airlie <airlied@linux.ie>; Daniel Vetter <daniel@ffwll.ch>; Rob Herring <robh+dt@kernel.org>; Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>; open list:DRM DRIVERS <dri-devel@lists.freedesktop.org>; open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS <devicetree@vger.kernel.org>; open list <linux-kernel@vger.kernel.org>
> Subject: Re: [PATCH v3 1/2] dt-bindings: it6505: add properties to restrict output bandwidth
> 
> On 06/10/2022 04:04, allen wrote:
>> From: allen chen <allen.chen@ite.com.tw>
>>
>> Add properties to restrict dp output data-lanes and clock.
>>
>> Signed-off-by: Pin-Yen Lin <treapking@chromium.org>
>> Signed-off-by: Allen Chen <allen.chen@ite.com.tw>
>> ---
>>  .../bindings/display/bridge/ite,it6505.yaml          | 12 ++++++++++++
>>  1 file changed, 12 insertions(+)
>>
>> diff --git 
>> a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml 
>> b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
>> index 833d11b2303a..f5482a614d05 100644
>> --- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
>> +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
>> @@ -52,6 +52,16 @@ properties:
>>      maxItems: 1
>>      description: extcon specifier for the Power Delivery
>>  
>> +  ite,dp-output-data-lane-count:
>> +    description: restrict the dp output data-lanes with value of 1-4
> 
> Drop "with value of 1-4" because it is redundant, but instead explain what this property is about. "Restrict output" is not yet enough.
> Restrict the number? Or choose specific lanes? Why it cannot be data-lanes from video-interfaces?
> 
> ==> DP output bandwidth depends on data-lane-count, so the number of output data-lane-count will restrict output bandwidth.
> In this dt-binding we don't have output endpoint, so use another property name to configure.
> If need to use data-lanes, where can we put in this dt-binding?

I see you got review in v2 to rename it, but it still should be the same
property, if it has similar/same meaning. It can be put here. You just
need to define its type or reference other schema (e.g. video-interfaces
if applicable) which defines it.

Best regards,
Krzysztof

Re: [PATCH v3 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

[Rob Herring]

On Thu, 06 Oct 2022 10:04:43 +0800, allen wrote:
> From: allen chen <allen.chen@ite.com.tw>
> 
> Add properties to restrict dp output data-lanes and clock.
> 
> Signed-off-by: Pin-Yen Lin <treapking@chromium.org>
> Signed-off-by: Allen Chen <allen.chen@ite.com.tw>
> ---
>  .../bindings/display/bridge/ite,it6505.yaml          | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml: properties:ite,dp-output-max-pixel-clock-mhz: '$ref' should not be valid under {'const': '$ref'}
	hint: Standard unit suffix properties don't need a type $ref
	from schema $id: http://devicetree.org/meta-schemas/core.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/patch/

This check can fail if there are any dependencies. The base for a patch
series is generally the most recent rc1.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit.

Re: [PATCH v3 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

[Rob Herring]

On Wed, Oct 5, 2022 at 9:05 PM allen <allen.chen@ite.com.tw> wrote:
>
> From: allen chen <allen.chen@ite.com.tw>
>
> Add properties to restrict dp output data-lanes and clock.
>
> Signed-off-by: Pin-Yen Lin <treapking@chromium.org>
> Signed-off-by: Allen Chen <allen.chen@ite.com.tw>
> ---
>  .../bindings/display/bridge/ite,it6505.yaml          | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> index 833d11b2303a..f5482a614d05 100644
> --- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> @@ -52,6 +52,16 @@ properties:
>      maxItems: 1
>      description: extcon specifier for the Power Delivery
>
> +  ite,dp-output-data-lane-count:
> +    description: restrict the dp output data-lanes with value of 1-4
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    enum: [ 1, 2, 4 ]

We have a standard property for lanes: data-lanes

It goes in the endpoint.

> +
> +  ite,dp-output-max-pixel-clock-mhz:
> +    description: restrict max pixel clock
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    default: 150

Also have a common property for this: 'link-frequencies'

[PATCH v3 2/2] drm/bridge: add it6505 driver to read data-lanes and max-pixel-clock-mhz from dt

[allen]

From: allen chen <allen.chen@ite.com.tw>

Add driver to read data-lanes and max-pixel-clock-mhz from dt property to
restrict output bandwidth.

Signed-off-by: Allen chen <allen.chen@ite.com.tw>
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
---
 drivers/gpu/drm/bridge/ite-it6505.c | 36 ++++++++++++++++++++++++++---
 1 file changed, 33 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 2767b70fa2cb..eca9a2c296a8 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -436,6 +436,8 @@ struct it6505 {
 	bool powered;
 	bool hpd_state;
 	u32 afe_setting;
+	u32 max_dpi_pixel_clock;
+	u32 max_lane_count;
 	enum hdcp_state hdcp_status;
 	struct delayed_work hdcp_work;
 	struct work_struct hdcp_wait_ksv_list;
@@ -1475,7 +1477,8 @@ static void it6505_parse_link_capabilities(struct it6505 *it6505)
 	it6505->lane_count = link->num_lanes;
 	DRM_DEV_DEBUG_DRIVER(dev, "Sink support %d lanes training",
 			     it6505->lane_count);
-	it6505->lane_count = min_t(int, it6505->lane_count, MAX_LANE_COUNT);
+	it6505->lane_count = min_t(int, it6505->lane_count,
+				   it6505->max_lane_count);
 
 	it6505->branch_device = drm_dp_is_branch(it6505->dpcd);
 	DRM_DEV_DEBUG_DRIVER(dev, "Sink %sbranch device",
@@ -2901,7 +2904,7 @@ it6505_bridge_mode_valid(struct drm_bridge *bridge,
 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 		return MODE_NO_INTERLACE;
 
-	if (mode->clock > DPI_PIXEL_CLK_MAX)
+	if (mode->clock > it6505->max_dpi_pixel_clock)
 		return MODE_CLOCK_HIGH;
 
 	it6505->video_info.clock = mode->clock;
@@ -3066,6 +3069,8 @@ static void it6505_parse_dt(struct it6505 *it6505)
 {
 	struct device *dev = &it6505->client->dev;
 	u32 *afe_setting = &it6505->afe_setting;
+	u32 *max_lane_count = &it6505->max_lane_count;
+	u32 *max_dpi_pixel_clock = &it6505->max_dpi_pixel_clock;
 
 	it6505->lane_swap_disabled =
 		device_property_read_bool(dev, "no-laneswap");
@@ -3081,7 +3086,32 @@ static void it6505_parse_dt(struct it6505 *it6505)
 	} else {
 		*afe_setting = 0;
 	}
-	DRM_DEV_DEBUG_DRIVER(dev, "using afe_setting: %d", *afe_setting);
+
+	if (device_property_read_u32(dev, "ite,dp-output-data-lane-count",
+				     max_lane_count) == 0) {
+		if (*max_lane_count > 4 || *max_lane_count == 3) {
+			dev_err(dev, "max lane count error, use default");
+			*max_lane_count = MAX_LANE_COUNT;
+		}
+	} else {
+		*max_lane_count = MAX_LANE_COUNT;
+	}
+
+	if (device_property_read_u32(dev, "ite,dp-output-max-pixel-clock-mhz",
+				     max_dpi_pixel_clock) == 0) {
+		*max_dpi_pixel_clock *= 1000;
+		if (*max_dpi_pixel_clock > 297000) {
+			dev_err(dev, "max pixel clock error, use default");
+			*max_dpi_pixel_clock = DPI_PIXEL_CLK_MAX;
+		}
+	} else {
+		*max_dpi_pixel_clock = DPI_PIXEL_CLK_MAX;
+	}
+
+	DRM_DEV_DEBUG_DRIVER(dev, "using afe_setting: %u, max_lane_count: %u",
+			     it6505->afe_setting, it6505->max_lane_count);
+	DRM_DEV_DEBUG_DRIVER(dev, "using max_dpi_pixel_clock: %u kHz",
+			     it6505->max_dpi_pixel_clock);
 }
 
 static ssize_t receive_timing_debugfs_show(struct file *file, char __user *buf,
-- 
2.25.1