[PATCH v2 0/2] *** IT6505 driver read dt properties ***

[PATCH v2 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.

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-khz from dt

 .../bindings/display/bridge/ite,it6505.yaml   | 10 ++++++
 drivers/gpu/drm/bridge/ite-it6505.c           | 35 +++++++++++++++++--
 2 files changed, 42 insertions(+), 3 deletions(-)

-- 
2.25.1

[PATCH v2 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>
---
 .../devicetree/bindings/display/bridge/ite,it6505.yaml | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
index 833d11b2303a..62b9f2192202 100644
--- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
@@ -52,6 +52,14 @@ properties:
     maxItems: 1
     description: extcon specifier for the Power Delivery
 
+  data-lanes:
+    maxItems: 1
+    description: restrict the dp output data-lanes with value of 1-4
+
+  max-pixel-clock-khz:
+    maxItems: 1
+    description: restrict max pixel clock
+
   port:
     $ref: /schemas/graph.yaml#/properties/port
     description: A port node pointing to DPI host port node
@@ -84,6 +92,8 @@ examples:
             pwr18-supply = <&it6505_pp18_reg>;
             reset-gpios = <&pio 179 1>;
             extcon = <&usbc_extcon>;
+            data-lanes = <2>;
+            max-pixel-clock-khz = <150000>;
 
             port {
                 it6505_in: endpoint {
-- 
2.25.1

Re: [PATCH v2 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

[Neil Armstrong]

Hi,

On 29/09/2022 03:44, 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>
> ---
>   .../devicetree/bindings/display/bridge/ite,it6505.yaml | 10 ++++++++++
>   1 file changed, 10 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> index 833d11b2303a..62b9f2192202 100644
> --- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> @@ -52,6 +52,14 @@ properties:
>       maxItems: 1
>       description: extcon specifier for the Power Delivery
>   
> +  data-lanes:
> +    maxItems: 1
> +    description: restrict the dp output data-lanes with value of 1-4

Can't you use the data-lanes property in the first port endpoint ?

Look at Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml

> +
> +  max-pixel-clock-khz:
> +    maxItems: 1
> +    description: restrict max pixel clock

New vendor specific properties should have the ite, prefix.

> +
>     port:
>       $ref: /schemas/graph.yaml#/properties/port
>       description: A port node pointing to DPI host port node
> @@ -84,6 +92,8 @@ examples:
>               pwr18-supply = <&it6505_pp18_reg>;
>               reset-gpios = <&pio 179 1>;
>               extcon = <&usbc_extcon>;
> +            data-lanes = <2>;
> +            max-pixel-clock-khz = <150000>;
>   
>               port {
>                   it6505_in: endpoint {

Thanks,
Neil

RE: [PATCH v2 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

[allen.chen]

Hi

data-lanes is output configuration. Maybe it is not suitable to put data-lanes in input endpoint.
extcon doesn't have output endpoint, so I don't know where to put is better.

-----Original Message-----
From: Neil Armstrong <neil.armstrong@linaro.org> 
Sent: Thursday, September 29, 2022 4:40 PM
To: Allen Chen (陳柏宇) <allen.chen@ite.com.tw>
Cc: open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS <devicetree@vger.kernel.org>; Kenneth Hung (洪家倫) <Kenneth.Hung@ite.com.tw>; Jernej Skrabec <jernej.skrabec@gmail.com>; Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>; Jau-Chih Tseng (曾昭智) <Jau-Chih.Tseng@ite.com.tw>; David Airlie <airlied@linux.ie>; open list:DRM DRIVERS <dri-devel@lists.freedesktop.org>; Neil Armstrong <narmstrong@baylibre.com>; open list <linux-kernel@vger.kernel.org>; Robert Foss <robert.foss@linaro.org>; Pin-yen Lin <treapking@chromium.org>; Hermes Wu (吳佳宏) <Hermes.Wu@ite.com.tw>; Rob Herring <robh+dt@kernel.org>; Laurent Pinchart <Laurent.pinchart@ideasonboard.com>; Andrzej Hajda <andrzej.hajda@intel.com>; Jonas Karlman <jonas@kwiboo.se>
Subject: Re: [PATCH v2 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

Hi,

On 29/09/2022 03:44, 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>
> ---
>   .../devicetree/bindings/display/bridge/ite,it6505.yaml | 10 ++++++++++
>   1 file changed, 10 insertions(+)
> 
> diff --git 
> a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml 
> b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> index 833d11b2303a..62b9f2192202 100644
> --- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> @@ -52,6 +52,14 @@ properties:
>       maxItems: 1
>       description: extcon specifier for the Power Delivery
>   
> +  data-lanes:
> +    maxItems: 1
> +    description: restrict the dp output data-lanes with value of 1-4

Can't you use the data-lanes property in the first port endpoint ?

Look at Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml

> +
> +  max-pixel-clock-khz:
> +    maxItems: 1
> +    description: restrict max pixel clock

New vendor specific properties should have the ite, prefix.

> +
>     port:
>       $ref: /schemas/graph.yaml#/properties/port
>       description: A port node pointing to DPI host port node @@ -84,6 
> +92,8 @@ examples:
>               pwr18-supply = <&it6505_pp18_reg>;
>               reset-gpios = <&pio 179 1>;
>               extcon = <&usbc_extcon>;
> +            data-lanes = <2>;
> +            max-pixel-clock-khz = <150000>;
>   
>               port {
>                   it6505_in: endpoint {

Thanks,
Neil

Re: [PATCH v2 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

[neil.armstrong]

On 05/10/2022 08:19, allen.chen@ite.com.tw wrote:
> Hi
> 
> data-lanes is output configuration. Maybe it is not suitable to put data-lanes in input endpoint.
> extcon doesn't have output endpoint, so I don't know where to put is better.

Ok it wasn't clear enough

Then rename the property to something more specific like:
ite,dp-output-data-lane-count

Use the same naming scheme for the other property:
ite,dp-output-max-pixel-clock-khz

Neil

> 
> -----Original Message-----
> From: Neil Armstrong <neil.armstrong@linaro.org>
> Sent: Thursday, September 29, 2022 4:40 PM
> To: Allen Chen (陳柏宇) <allen.chen@ite.com.tw>
> Cc: open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS <devicetree@vger.kernel.org>; Kenneth Hung (洪家倫) <Kenneth.Hung@ite.com.tw>; Jernej Skrabec <jernej.skrabec@gmail.com>; Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>; Jau-Chih Tseng (曾昭智) <Jau-Chih.Tseng@ite.com.tw>; David Airlie <airlied@linux.ie>; open list:DRM DRIVERS <dri-devel@lists.freedesktop.org>; Neil Armstrong <narmstrong@baylibre.com>; open list <linux-kernel@vger.kernel.org>; Robert Foss <robert.foss@linaro.org>; Pin-yen Lin <treapking@chromium.org>; Hermes Wu (吳佳宏) <Hermes.Wu@ite.com.tw>; Rob Herring <robh+dt@kernel.org>; Laurent Pinchart <Laurent.pinchart@ideasonboard.com>; Andrzej Hajda <andrzej.hajda@intel.com>; Jonas Karlman <jonas@kwiboo.se>
> Subject: Re: [PATCH v2 1/2] dt-bindings: it6505: add properties to restrict output bandwidth
> 
> Hi,
> 
> On 29/09/2022 03:44, 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>
>> ---
>>    .../devicetree/bindings/display/bridge/ite,it6505.yaml | 10 ++++++++++
>>    1 file changed, 10 insertions(+)
>>
>> diff --git
>> a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
>> b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
>> index 833d11b2303a..62b9f2192202 100644
>> --- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
>> +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
>> @@ -52,6 +52,14 @@ properties:
>>        maxItems: 1
>>        description: extcon specifier for the Power Delivery
>>    
>> +  data-lanes:
>> +    maxItems: 1
>> +    description: restrict the dp output data-lanes with value of 1-4
> 
> Can't you use the data-lanes property in the first port endpoint ?
> 
> Look at Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
> 
>> +
>> +  max-pixel-clock-khz:
>> +    maxItems: 1
>> +    description: restrict max pixel clock
> 
> New vendor specific properties should have the ite, prefix.
> 
>> +
>>      port:
>>        $ref: /schemas/graph.yaml#/properties/port
>>        description: A port node pointing to DPI host port node @@ -84,6
>> +92,8 @@ examples:
>>                pwr18-supply = <&it6505_pp18_reg>;
>>                reset-gpios = <&pio 179 1>;
>>                extcon = <&usbc_extcon>;
>> +            data-lanes = <2>;
>> +            max-pixel-clock-khz = <150000>;
>>    
>>                port {
>>                    it6505_in: endpoint {
> 
> Thanks,
> Neil

Re: [PATCH v2 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

[Krzysztof Kozlowski]

On 29/09/2022 03:44, 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>
> ---
>  .../devicetree/bindings/display/bridge/ite,it6505.yaml | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> index 833d11b2303a..62b9f2192202 100644
> --- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> @@ -52,6 +52,14 @@ properties:
>      maxItems: 1
>      description: extcon specifier for the Power Delivery
>  
> +  data-lanes:
> +    maxItems: 1
> +    description: restrict the dp output data-lanes with value of 1-4

Where is the definition of this property?

> +
> +  max-pixel-clock-khz:
> +    maxItems: 1
> +    description: restrict max pixel clock

This looks wrong. You do not use proper unit suffix
(https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml),
no vendor prefix, no type and weird maxItems like it was array. Is it
coming from any other schema?

Best regards,
Krzysztof

[PATCH v2 2/2] drm/bridge: add it6505 driver to read data-lanes and max-pixel-clock-khz from dt

[allen]

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

Add driver to read data-lanes and max-pixel-clock-khz 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 | 35 ++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 2767b70fa2cb..cfa25a176a29 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 +3086,31 @@ 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, "data-lanes",
+				     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, "max-pixel-clock-khz",
+				     max_dpi_pixel_clock) == 0) {
+		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