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* [PATCH v2 0/2] ARM: dts: da850: tilcdc related DT changes
@ 2016-11-28 12:15 ` Bartosz Golaszewski
  0 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-28 12:15 UTC (permalink / raw)
  To: Kevin Hilman, Michael Turquette, Sekhar Nori, Rob Herring,
	Frank Rowand, Mark Rutland, Peter Ujfalusi, Russell King
  Cc: LKML, arm-soc, linux-drm, linux-devicetree, Jyri Sarha,
	Tomi Valkeinen, David Airlie, Laurent Pinchart,
	Bartosz Golaszewski

This series contains the last DT changes required for LCDC support
on da850-lcdk. The first one adds the dumb-vga-dac nodes, the second
limits the maximum pixel clock rate.

v1 -> v2:
- drop patch 3/3 (already merged)
- use max-pixelclock instead of max-bandwidth for display mode limiting

Bartosz Golaszewski (2):
  ARM: dts: da850-lcdk: add the dumb-vga-dac node
  ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc

 arch/arm/boot/dts/da850-lcdk.dts | 59 ++++++++++++++++++++++++++++++++++++++++
 arch/arm/boot/dts/da850.dtsi     | 17 ++++++++++++
 2 files changed, 76 insertions(+)

-- 
2.9.3

^ permalink raw reply	[flat|nested] 15+ messages in thread
* [PATCH v2 0/2] ARM: dts: da850: tilcdc related DT changes
@ 2016-11-28 12:15 ` Bartosz Golaszewski
  0 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-28 12:15 UTC (permalink / raw)
  To: Kevin Hilman, Michael Turquette, Sekhar Nori, Rob Herring,
	Frank Rowand, Mark Rutland, Peter Ujfalusi, Russell King
  Cc: linux-devicetree, LKML, linux-drm, Bartosz Golaszewski,
	Tomi Valkeinen, Jyri Sarha, arm-soc, Laurent Pinchart

This series contains the last DT changes required for LCDC support
on da850-lcdk. The first one adds the dumb-vga-dac nodes, the second
limits the maximum pixel clock rate.

v1 -> v2:
- drop patch 3/3 (already merged)
- use max-pixelclock instead of max-bandwidth for display mode limiting

Bartosz Golaszewski (2):
  ARM: dts: da850-lcdk: add the dumb-vga-dac node
  ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc

 arch/arm/boot/dts/da850-lcdk.dts | 59 ++++++++++++++++++++++++++++++++++++++++
 arch/arm/boot/dts/da850.dtsi     | 17 ++++++++++++
 2 files changed, 76 insertions(+)

-- 
2.9.3

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 15+ messages in thread
* [PATCH v2 0/2] ARM: dts: da850: tilcdc related DT changes
@ 2016-11-28 12:15 ` Bartosz Golaszewski
  0 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-28 12:15 UTC (permalink / raw)
  To: linux-arm-kernel

This series contains the last DT changes required for LCDC support
on da850-lcdk. The first one adds the dumb-vga-dac nodes, the second
limits the maximum pixel clock rate.

v1 -> v2:
- drop patch 3/3 (already merged)
- use max-pixelclock instead of max-bandwidth for display mode limiting

Bartosz Golaszewski (2):
  ARM: dts: da850-lcdk: add the dumb-vga-dac node
  ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc

 arch/arm/boot/dts/da850-lcdk.dts | 59 ++++++++++++++++++++++++++++++++++++++++
 arch/arm/boot/dts/da850.dtsi     | 17 ++++++++++++
 2 files changed, 76 insertions(+)

-- 
2.9.3

^ permalink raw reply	[flat|nested] 15+ messages in thread
* [PATCH v2 1/2] ARM: dts: da850-lcdk: add the dumb-vga-dac node
  2016-11-28 12:15 ` Bartosz Golaszewski
  (?)
@ 2016-11-28 12:15   ` Bartosz Golaszewski
  -1 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-28 12:15 UTC (permalink / raw)
  To: Kevin Hilman, Michael Turquette, Sekhar Nori, Rob Herring,
	Frank Rowand, Mark Rutland, Peter Ujfalusi, Russell King
  Cc: LKML, arm-soc, linux-drm, linux-devicetree, Jyri Sarha,
	Tomi Valkeinen, David Airlie, Laurent Pinchart,
	Bartosz Golaszewski

Add the dumb-vga-dac node to the board DT together with corresponding
ports and vga connector. This allows to retrieve the edid info from
the display automatically.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850-lcdk.dts | 58 ++++++++++++++++++++++++++++++++++++++++
 arch/arm/boot/dts/da850.dtsi     | 17 ++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
index 711b9ad..d864f11 100644
--- a/arch/arm/boot/dts/da850-lcdk.dts
+++ b/arch/arm/boot/dts/da850-lcdk.dts
@@ -50,6 +50,53 @@
 			system-clock-frequency = <24576000>;
 		};
 	};
+
+	vga_bridge {
+		compatible = "dumb-vga-dac";
+		pinctrl-names = "default";
+		pinctrl-0 = <&lcd_pins>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				reg = <0>;
+
+				vga_bridge_in: endpoint@0 {
+					reg = <0>;
+					remote-endpoint = <&display_out_vga>;
+				};
+			};
+
+			port@1 {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				reg = <1>;
+
+				vga_bridge_out: endpoint@0 {
+					reg = <0>;
+					remote-endpoint = <&vga_con_in>;
+				};
+			};
+		};
+	};
+
+	vga {
+		compatible = "vga-connector";
+
+		ddc-i2c-bus = <&i2c0>;
+
+		port {
+			vga_con_in: endpoint {
+				remote-endpoint = <&vga_bridge_out>;
+			};
+		};
+	};
 };
 
 &pmx_core {
@@ -235,3 +282,14 @@
 &memctrl {
 	status = "okay";
 };
+
+&display {
+	status = "okay";
+};
+
+&display_out {
+	display_out_vga: endpoint@0 {
+		reg = <0>;
+		remote-endpoint = <&vga_bridge_in>;
+	};
+};
diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
index 4070619..5f4ba2e 100644
--- a/arch/arm/boot/dts/da850.dtsi
+++ b/arch/arm/boot/dts/da850.dtsi
@@ -454,6 +454,23 @@
 			reg = <0x213000 0x1000>;
 			interrupts = <52>;
 			status = "disabled";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				display_in: port@0 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <0>;
+				};
+
+				display_out: port@1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+				};
+			};
 		};
 	};
 	aemif: aemif@68000000 {
-- 
2.9.3

^ permalink raw reply related	[flat|nested] 15+ messages in thread
* [PATCH v2 1/2] ARM: dts: da850-lcdk: add the dumb-vga-dac node
@ 2016-11-28 12:15   ` Bartosz Golaszewski
  0 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-28 12:15 UTC (permalink / raw)
  To: Kevin Hilman, Michael Turquette, Sekhar Nori, Rob Herring,
	Frank Rowand, Mark Rutland, Peter Ujfalusi, Russell King
  Cc: linux-devicetree, LKML, linux-drm, Bartosz Golaszewski,
	Tomi Valkeinen, Jyri Sarha, arm-soc, Laurent Pinchart

Add the dumb-vga-dac node to the board DT together with corresponding
ports and vga connector. This allows to retrieve the edid info from
the display automatically.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850-lcdk.dts | 58 ++++++++++++++++++++++++++++++++++++++++
 arch/arm/boot/dts/da850.dtsi     | 17 ++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
index 711b9ad..d864f11 100644
--- a/arch/arm/boot/dts/da850-lcdk.dts
+++ b/arch/arm/boot/dts/da850-lcdk.dts
@@ -50,6 +50,53 @@
 			system-clock-frequency = <24576000>;
 		};
 	};
+
+	vga_bridge {
+		compatible = "dumb-vga-dac";
+		pinctrl-names = "default";
+		pinctrl-0 = <&lcd_pins>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				reg = <0>;
+
+				vga_bridge_in: endpoint@0 {
+					reg = <0>;
+					remote-endpoint = <&display_out_vga>;
+				};
+			};
+
+			port@1 {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				reg = <1>;
+
+				vga_bridge_out: endpoint@0 {
+					reg = <0>;
+					remote-endpoint = <&vga_con_in>;
+				};
+			};
+		};
+	};
+
+	vga {
+		compatible = "vga-connector";
+
+		ddc-i2c-bus = <&i2c0>;
+
+		port {
+			vga_con_in: endpoint {
+				remote-endpoint = <&vga_bridge_out>;
+			};
+		};
+	};
 };
 
 &pmx_core {
@@ -235,3 +282,14 @@
 &memctrl {
 	status = "okay";
 };
+
+&display {
+	status = "okay";
+};
+
+&display_out {
+	display_out_vga: endpoint@0 {
+		reg = <0>;
+		remote-endpoint = <&vga_bridge_in>;
+	};
+};
diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
index 4070619..5f4ba2e 100644
--- a/arch/arm/boot/dts/da850.dtsi
+++ b/arch/arm/boot/dts/da850.dtsi
@@ -454,6 +454,23 @@
 			reg = <0x213000 0x1000>;
 			interrupts = <52>;
 			status = "disabled";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				display_in: port@0 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <0>;
+				};
+
+				display_out: port@1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+				};
+			};
 		};
 	};
 	aemif: aemif@68000000 {
-- 
2.9.3

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply related	[flat|nested] 15+ messages in thread
* [PATCH v2 1/2] ARM: dts: da850-lcdk: add the dumb-vga-dac node
@ 2016-11-28 12:15   ` Bartosz Golaszewski
  0 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-28 12:15 UTC (permalink / raw)
  To: linux-arm-kernel

Add the dumb-vga-dac node to the board DT together with corresponding
ports and vga connector. This allows to retrieve the edid info from
the display automatically.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850-lcdk.dts | 58 ++++++++++++++++++++++++++++++++++++++++
 arch/arm/boot/dts/da850.dtsi     | 17 ++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
index 711b9ad..d864f11 100644
--- a/arch/arm/boot/dts/da850-lcdk.dts
+++ b/arch/arm/boot/dts/da850-lcdk.dts
@@ -50,6 +50,53 @@
 			system-clock-frequency = <24576000>;
 		};
 	};
+
+	vga_bridge {
+		compatible = "dumb-vga-dac";
+		pinctrl-names = "default";
+		pinctrl-0 = <&lcd_pins>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port at 0 {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				reg = <0>;
+
+				vga_bridge_in: endpoint at 0 {
+					reg = <0>;
+					remote-endpoint = <&display_out_vga>;
+				};
+			};
+
+			port at 1 {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				reg = <1>;
+
+				vga_bridge_out: endpoint at 0 {
+					reg = <0>;
+					remote-endpoint = <&vga_con_in>;
+				};
+			};
+		};
+	};
+
+	vga {
+		compatible = "vga-connector";
+
+		ddc-i2c-bus = <&i2c0>;
+
+		port {
+			vga_con_in: endpoint {
+				remote-endpoint = <&vga_bridge_out>;
+			};
+		};
+	};
 };
 
 &pmx_core {
@@ -235,3 +282,14 @@
 &memctrl {
 	status = "okay";
 };
+
+&display {
+	status = "okay";
+};
+
+&display_out {
+	display_out_vga: endpoint at 0 {
+		reg = <0>;
+		remote-endpoint = <&vga_bridge_in>;
+	};
+};
diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
index 4070619..5f4ba2e 100644
--- a/arch/arm/boot/dts/da850.dtsi
+++ b/arch/arm/boot/dts/da850.dtsi
@@ -454,6 +454,23 @@
 			reg = <0x213000 0x1000>;
 			interrupts = <52>;
 			status = "disabled";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				display_in: port at 0 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <0>;
+				};
+
+				display_out: port at 1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+				};
+			};
 		};
 	};
 	aemif: aemif at 68000000 {
-- 
2.9.3

^ permalink raw reply related	[flat|nested] 15+ messages in thread
* [PATCH v2 2/2] ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc
  2016-11-28 12:15 ` Bartosz Golaszewski
  (?)
@ 2016-11-28 12:15   ` Bartosz Golaszewski
  -1 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-28 12:15 UTC (permalink / raw)
  To: Kevin Hilman, Michael Turquette, Sekhar Nori, Rob Herring,
	Frank Rowand, Mark Rutland, Peter Ujfalusi, Russell King
  Cc: LKML, arm-soc, linux-drm, linux-devicetree, Jyri Sarha,
	Tomi Valkeinen, David Airlie, Laurent Pinchart,
	Bartosz Golaszewski

Due to memory throughput constraints any display mode for which the
pixel clock rate exceeds the recommended value of 37500 KHz must be
filtered out.

Specify the max-pixelclock property for the display node for
da850-lcdk.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850-lcdk.dts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
index d864f11..1283263 100644
--- a/arch/arm/boot/dts/da850-lcdk.dts
+++ b/arch/arm/boot/dts/da850-lcdk.dts
@@ -285,6 +285,7 @@
 
 &display {
 	status = "okay";
+	max-pixelclock = <37500>;
 };
 
 &display_out {
-- 
2.9.3

^ permalink raw reply related	[flat|nested] 15+ messages in thread
* [PATCH v2 2/2] ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc
@ 2016-11-28 12:15   ` Bartosz Golaszewski
  0 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-28 12:15 UTC (permalink / raw)
  To: Kevin Hilman, Michael Turquette, Sekhar Nori, Rob Herring,
	Frank Rowand, Mark Rutland, Peter Ujfalusi, Russell King
  Cc: linux-devicetree, LKML, linux-drm, Bartosz Golaszewski,
	Tomi Valkeinen, Jyri Sarha, arm-soc, Laurent Pinchart

Due to memory throughput constraints any display mode for which the
pixel clock rate exceeds the recommended value of 37500 KHz must be
filtered out.

Specify the max-pixelclock property for the display node for
da850-lcdk.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850-lcdk.dts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
index d864f11..1283263 100644
--- a/arch/arm/boot/dts/da850-lcdk.dts
+++ b/arch/arm/boot/dts/da850-lcdk.dts
@@ -285,6 +285,7 @@
 
 &display {
 	status = "okay";
+	max-pixelclock = <37500>;
 };
 
 &display_out {
-- 
2.9.3

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply related	[flat|nested] 15+ messages in thread
* [PATCH v2 2/2] ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc
@ 2016-11-28 12:15   ` Bartosz Golaszewski
  0 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-28 12:15 UTC (permalink / raw)
  To: linux-arm-kernel

Due to memory throughput constraints any display mode for which the
pixel clock rate exceeds the recommended value of 37500 KHz must be
filtered out.

Specify the max-pixelclock property for the display node for
da850-lcdk.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850-lcdk.dts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
index d864f11..1283263 100644
--- a/arch/arm/boot/dts/da850-lcdk.dts
+++ b/arch/arm/boot/dts/da850-lcdk.dts
@@ -285,6 +285,7 @@
 
 &display {
 	status = "okay";
+	max-pixelclock = <37500>;
 };
 
 &display_out {
-- 
2.9.3

^ permalink raw reply related	[flat|nested] 15+ messages in thread
* Re: [PATCH v2 2/2] ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc
@ 2016-11-29 10:53     ` Sekhar Nori
  0 siblings, 0 replies; 15+ messages in thread
From: Sekhar Nori @ 2016-11-29 10:53 UTC (permalink / raw)
  To: Bartosz Golaszewski, Kevin Hilman, Michael Turquette,
	Rob Herring, Frank Rowand, Mark Rutland, Peter Ujfalusi,
	Russell King
  Cc: LKML, arm-soc, linux-drm, linux-devicetree, Jyri Sarha,
	Tomi Valkeinen, David Airlie, Laurent Pinchart

On Monday 28 November 2016 05:45 PM, Bartosz Golaszewski wrote:
> Due to memory throughput constraints any display mode for which the
> pixel clock rate exceeds the recommended value of 37500 KHz must be
> filtered out.

I think there might be more reasons than memory throughput constraints
for the reasoning behind 37.5Mhz cap on pixel clock. Why not just refer
to the datasheet section that places this constraint so we know its a
hardware restriction.

> 
> Specify the max-pixelclock property for the display node for
> da850-lcdk.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  arch/arm/boot/dts/da850-lcdk.dts | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
> index d864f11..1283263 100644
> --- a/arch/arm/boot/dts/da850-lcdk.dts
> +++ b/arch/arm/boot/dts/da850-lcdk.dts
> @@ -285,6 +285,7 @@
>  
>  &display {
>  	status = "okay";
> +	max-pixelclock = <37500>;

Should this not be in da850.dtsi since its an SoC imposed constraint? If
a board needs narrower constraint, it can override it. But I guess most
well designed boards will just hit the SoC constraint.

Thanks,
Sekhar

^ permalink raw reply	[flat|nested] 15+ messages in thread
* Re: [PATCH v2 2/2] ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc
@ 2016-11-29 10:53     ` Sekhar Nori
  0 siblings, 0 replies; 15+ messages in thread
From: Sekhar Nori @ 2016-11-29 10:53 UTC (permalink / raw)
  To: Bartosz Golaszewski, Kevin Hilman, Michael Turquette,
	Rob Herring, Frank Rowand, Mark Rutland, Peter Ujfalusi,
	Russell King
  Cc: LKML, arm-soc, linux-drm, linux-devicetree, Jyri Sarha,
	Tomi Valkeinen, David Airlie, Laurent Pinchart

On Monday 28 November 2016 05:45 PM, Bartosz Golaszewski wrote:
> Due to memory throughput constraints any display mode for which the
> pixel clock rate exceeds the recommended value of 37500 KHz must be
> filtered out.

I think there might be more reasons than memory throughput constraints
for the reasoning behind 37.5Mhz cap on pixel clock. Why not just refer
to the datasheet section that places this constraint so we know its a
hardware restriction.

> 
> Specify the max-pixelclock property for the display node for
> da850-lcdk.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
> ---
>  arch/arm/boot/dts/da850-lcdk.dts | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
> index d864f11..1283263 100644
> --- a/arch/arm/boot/dts/da850-lcdk.dts
> +++ b/arch/arm/boot/dts/da850-lcdk.dts
> @@ -285,6 +285,7 @@
>  
>  &display {
>  	status = "okay";
> +	max-pixelclock = <37500>;

Should this not be in da850.dtsi since its an SoC imposed constraint? If
a board needs narrower constraint, it can override it. But I guess most
well designed boards will just hit the SoC constraint.

Thanks,
Sekhar
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^ permalink raw reply	[flat|nested] 15+ messages in thread
* [PATCH v2 2/2] ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc
@ 2016-11-29 10:53     ` Sekhar Nori
  0 siblings, 0 replies; 15+ messages in thread
From: Sekhar Nori @ 2016-11-29 10:53 UTC (permalink / raw)
  To: linux-arm-kernel

On Monday 28 November 2016 05:45 PM, Bartosz Golaszewski wrote:
> Due to memory throughput constraints any display mode for which the
> pixel clock rate exceeds the recommended value of 37500 KHz must be
> filtered out.

I think there might be more reasons than memory throughput constraints
for the reasoning behind 37.5Mhz cap on pixel clock. Why not just refer
to the datasheet section that places this constraint so we know its a
hardware restriction.

> 
> Specify the max-pixelclock property for the display node for
> da850-lcdk.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  arch/arm/boot/dts/da850-lcdk.dts | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
> index d864f11..1283263 100644
> --- a/arch/arm/boot/dts/da850-lcdk.dts
> +++ b/arch/arm/boot/dts/da850-lcdk.dts
> @@ -285,6 +285,7 @@
>  
>  &display {
>  	status = "okay";
> +	max-pixelclock = <37500>;

Should this not be in da850.dtsi since its an SoC imposed constraint? If
a board needs narrower constraint, it can override it. But I guess most
well designed boards will just hit the SoC constraint.

Thanks,
Sekhar

^ permalink raw reply	[flat|nested] 15+ messages in thread
* Re: [PATCH v2 2/2] ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc
  2016-11-29 10:53     ` Sekhar Nori
  (?)
@ 2016-11-29 11:57       ` Bartosz Golaszewski
  -1 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-29 11:57 UTC (permalink / raw)
  To: Sekhar Nori
  Cc: Kevin Hilman, Michael Turquette, Rob Herring, Frank Rowand,
	Mark Rutland, Peter Ujfalusi, Russell King, LKML, arm-soc,
	linux-drm, linux-devicetree, Jyri Sarha, Tomi Valkeinen,
	David Airlie, Laurent Pinchart

2016-11-29 11:53 GMT+01:00 Sekhar Nori <nsekhar@ti.com>:
> On Monday 28 November 2016 05:45 PM, Bartosz Golaszewski wrote:
>> Due to memory throughput constraints any display mode for which the
>> pixel clock rate exceeds the recommended value of 37500 KHz must be
>> filtered out.
>
> I think there might be more reasons than memory throughput constraints
> for the reasoning behind 37.5Mhz cap on pixel clock. Why not just refer
> to the datasheet section that places this constraint so we know its a
> hardware restriction.
>
>>
>> Specify the max-pixelclock property for the display node for
>> da850-lcdk.
>>
>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>> ---
>>  arch/arm/boot/dts/da850-lcdk.dts | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
>> index d864f11..1283263 100644
>> --- a/arch/arm/boot/dts/da850-lcdk.dts
>> +++ b/arch/arm/boot/dts/da850-lcdk.dts
>> @@ -285,6 +285,7 @@
>>
>>  &display {
>>       status = "okay";
>> +     max-pixelclock = <37500>;
>
> Should this not be in da850.dtsi since its an SoC imposed constraint? If
> a board needs narrower constraint, it can override it. But I guess most
> well designed boards will just hit the SoC constraint.
>

Both issues fixed in v3.

Thanks,
Bartosz Golaszewski

^ permalink raw reply	[flat|nested] 15+ messages in thread
* Re: [PATCH v2 2/2] ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc
@ 2016-11-29 11:57       ` Bartosz Golaszewski
  0 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-29 11:57 UTC (permalink / raw)
  To: Sekhar Nori
  Cc: Mark Rutland, linux-devicetree, Tomi Valkeinen, Kevin Hilman,
	Michael Turquette, Russell King, linux-drm, LKML, Peter Ujfalusi,
	Rob Herring, Jyri Sarha, Frank Rowand, arm-soc, Laurent Pinchart

2016-11-29 11:53 GMT+01:00 Sekhar Nori <nsekhar@ti.com>:
> On Monday 28 November 2016 05:45 PM, Bartosz Golaszewski wrote:
>> Due to memory throughput constraints any display mode for which the
>> pixel clock rate exceeds the recommended value of 37500 KHz must be
>> filtered out.
>
> I think there might be more reasons than memory throughput constraints
> for the reasoning behind 37.5Mhz cap on pixel clock. Why not just refer
> to the datasheet section that places this constraint so we know its a
> hardware restriction.
>
>>
>> Specify the max-pixelclock property for the display node for
>> da850-lcdk.
>>
>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>> ---
>>  arch/arm/boot/dts/da850-lcdk.dts | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
>> index d864f11..1283263 100644
>> --- a/arch/arm/boot/dts/da850-lcdk.dts
>> +++ b/arch/arm/boot/dts/da850-lcdk.dts
>> @@ -285,6 +285,7 @@
>>
>>  &display {
>>       status = "okay";
>> +     max-pixelclock = <37500>;
>
> Should this not be in da850.dtsi since its an SoC imposed constraint? If
> a board needs narrower constraint, it can override it. But I guess most
> well designed boards will just hit the SoC constraint.
>

Both issues fixed in v3.

Thanks,
Bartosz Golaszewski
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dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 15+ messages in thread
* [PATCH v2 2/2] ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc
@ 2016-11-29 11:57       ` Bartosz Golaszewski
  0 siblings, 0 replies; 15+ messages in thread
From: Bartosz Golaszewski @ 2016-11-29 11:57 UTC (permalink / raw)
  To: linux-arm-kernel

2016-11-29 11:53 GMT+01:00 Sekhar Nori <nsekhar@ti.com>:
> On Monday 28 November 2016 05:45 PM, Bartosz Golaszewski wrote:
>> Due to memory throughput constraints any display mode for which the
>> pixel clock rate exceeds the recommended value of 37500 KHz must be
>> filtered out.
>
> I think there might be more reasons than memory throughput constraints
> for the reasoning behind 37.5Mhz cap on pixel clock. Why not just refer
> to the datasheet section that places this constraint so we know its a
> hardware restriction.
>
>>
>> Specify the max-pixelclock property for the display node for
>> da850-lcdk.
>>
>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>> ---
>>  arch/arm/boot/dts/da850-lcdk.dts | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
>> index d864f11..1283263 100644
>> --- a/arch/arm/boot/dts/da850-lcdk.dts
>> +++ b/arch/arm/boot/dts/da850-lcdk.dts
>> @@ -285,6 +285,7 @@
>>
>>  &display {
>>       status = "okay";
>> +     max-pixelclock = <37500>;
>
> Should this not be in da850.dtsi since its an SoC imposed constraint? If
> a board needs narrower constraint, it can override it. But I guess most
> well designed boards will just hit the SoC constraint.
>

Both issues fixed in v3.

Thanks,
Bartosz Golaszewski

^ permalink raw reply	[flat|nested] 15+ messages in thread
end of thread, other threads:[~2016-11-29 11:58 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-11-28 12:15 [PATCH v2 0/2] ARM: dts: da850: tilcdc related DT changes Bartosz Golaszewski
2016-11-28 12:15 ` Bartosz Golaszewski
2016-11-28 12:15 ` Bartosz Golaszewski
2016-11-28 12:15 ` [PATCH v2 1/2] ARM: dts: da850-lcdk: add the dumb-vga-dac node Bartosz Golaszewski
2016-11-28 12:15   ` Bartosz Golaszewski
2016-11-28 12:15   ` Bartosz Golaszewski
2016-11-28 12:15 ` [PATCH v2 2/2] ARM: dts: da850-lcdk: specify the maximum pixel clock rate for tilcdc Bartosz Golaszewski
2016-11-28 12:15   ` Bartosz Golaszewski
2016-11-28 12:15   ` Bartosz Golaszewski
2016-11-29 10:53   ` Sekhar Nori
2016-11-29 10:53     ` Sekhar Nori
2016-11-29 10:53     ` Sekhar Nori
2016-11-29 11:57     ` Bartosz Golaszewski
2016-11-29 11:57       ` Bartosz Golaszewski
2016-11-29 11:57       ` Bartosz Golaszewski

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