[PATCH 1/3] arm64: dts: imx8mm: Reduce GPU to nominal speed

[PATCH 1/3] arm64: dts: imx8mm: Reduce GPU to nominal speed

[Adam Ford]

When the GPU nodes were added, the GPU_PLL_OUT was configured
for 1000MHz, but this requires the SoC to run in overdrive mode
which requires an elevated voltage operating point.

Since this may run some boards out of spec, the default clock
should be set to 800MHz for nominal operating mode. Boards
that run at the higher voltage can update their clocks
accordingly.

Fixes: 4523be8e46be ("arm64: dts: imx8mm: Add GPU nodes for 2D and 3D core")
Signed-off-by: Adam Ford <aford173@gmail.com>

diff --git a/arch/arm64/boot/dts/freescale/imx8mm.dtsi b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
index 669fdd2c54e4..b33bc4855e5f 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
@@ -1402,7 +1402,7 @@ gpu_3d: gpu@38000000 {
 			assigned-clocks = <&clk IMX8MM_CLK_GPU3D_CORE>,
 					  <&clk IMX8MM_GPU_PLL_OUT>;
 			assigned-clock-parents = <&clk IMX8MM_GPU_PLL_OUT>;
-			assigned-clock-rates = <0>, <1000000000>;
+			assigned-clock-rates = <0>, <800000000>;
 			power-domains = <&pgc_gpu>;
 		};
 
@@ -1417,7 +1417,7 @@ gpu_2d: gpu@38008000 {
 			assigned-clocks = <&clk IMX8MM_CLK_GPU2D_CORE>,
 					  <&clk IMX8MM_GPU_PLL_OUT>;
 			assigned-clock-parents = <&clk IMX8MM_GPU_PLL_OUT>;
-			assigned-clock-rates = <0>, <1000000000>;
+			assigned-clock-rates = <0>, <800000000>;
 			power-domains = <&pgc_gpu>;
 		};
 
-- 
2.40.1

[PATCH 2/3] arm64: dts: imx8mm: Add optional overdrive DTSI

[Adam Ford]

For boards who run their SoC at a higher voltage than nominal,
the boards can run several clocks at an overdrive rate for
better performance.  Add an optional DTSI file which can be
included by various boards to run in overdrive mode.

This raises the GPU PLL to 1000MHz, and the VPU PLL to
700MHz while moving VPU_G1 and VPU_H1 to the SYS_PLL3_OUT
which runs at 750MHz.

Signed-off-by: Adam Ford <aford173@gmail.com>

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-overdrive.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-overdrive.dtsi
new file mode 100644
index 000000000000..b31436b5e9b7
--- /dev/null
+++ b/arch/arm64/boot/dts/freescale/imx8mm-overdrive.dtsi
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+&gpu_2d {
+	assigned-clocks = <&clk IMX8MM_CLK_GPU2D_CORE>,
+			  <&clk IMX8MM_GPU_PLL_OUT>;
+	assigned-clock-parents = <&clk IMX8MM_GPU_PLL_OUT>;
+	assigned-clock-rates = <0>, <1000000000>;
+};
+
+&gpu_3d {
+	assigned-clocks = <&clk IMX8MM_CLK_GPU3D_CORE>,
+			  <&clk IMX8MM_GPU_PLL_OUT>;
+	assigned-clock-parents = <&clk IMX8MM_GPU_PLL_OUT>;
+	assigned-clock-rates = <0>, <1000000000>;
+};
+
+&vpu_blk_ctrl {
+	assigned-clocks = <&clk IMX8MM_CLK_VPU_G1>,
+			  <&clk IMX8MM_CLK_VPU_G2>,
+			  <&clk IMX8MM_CLK_VPU_H1>,
+			  <&clk IMX8MM_VPU_PLL_OUT>;
+	assigned-clock-parents = <&clk IMX8MM_SYS_PLL3_OUT>,
+				 <&clk IMX8MM_VPU_PLL_OUT>,
+				 <&clk IMX8MM_SYS_PLL3_OUT>;
+	assigned-clock-rates = <750000000>,
+			       <700000000>,
+			       <750000000>,
+			       <700000000>;
+};
-- 
2.40.1

[PATCH 3/3] arm64: dts: imx8mm-beacon: Enable overdrive mode

[Adam Ford]

The SoC runs at a high enough voltage to support overdrive
mode, so include the imx8mm-overdrive.dtsi file to increase
the VPU and GPU clocks to their overdrive speeds.

Signed-off-by: Adam Ford <aford173@gmail.com>

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
index f264102bdb27..62ed64663f49 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
@@ -3,6 +3,8 @@
  * Copyright 2020 Compass Electronics Group, LLC
  */
 
+#include "imx8mm-overdrive.dtsi"
+
 / {
 	aliases {
 		rtc0 = &rtc;
-- 
2.40.1

Re: [PATCH 1/3] arm64: dts: imx8mm: Reduce GPU to nominal speed

[Shawn Guo]

On Tue, Nov 28, 2023 at 02:02:16PM -0600, Adam Ford wrote:
> When the GPU nodes were added, the GPU_PLL_OUT was configured
> for 1000MHz, but this requires the SoC to run in overdrive mode
> which requires an elevated voltage operating point.
> 
> Since this may run some boards out of spec, the default clock
> should be set to 800MHz for nominal operating mode. Boards
> that run at the higher voltage can update their clocks
> accordingly.
> 
> Fixes: 4523be8e46be ("arm64: dts: imx8mm: Add GPU nodes for 2D and 3D core")
> Signed-off-by: Adam Ford <aford173@gmail.com>

Applied all, thanks!