VAR-SOM-MX8M-MINI-CAN: Difference between revisions

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Line 9: Line 9:
Yocto Dunfell releases dunfell-fslc-5.4-2.1.x-mx8mm-v1.3 & dunfell-fslc-5.4-2.1.x-mx8mn-v1.2<br>
Yocto Dunfell releases dunfell-fslc-5.4-2.1.x-mx8mm-v1.3 & dunfell-fslc-5.4-2.1.x-mx8mn-v1.2<br>
Android 10 releases q10.0.0_1.0.0-ga_dart-mx8mm_v1.6 & android-10.0.0_2.3.0-ga_mx8mn_v1.4<br>
Android 10 releases q10.0.0_1.0.0-ga_dart-mx8mm_v1.6 & android-10.0.0_2.3.0-ga_mx8mn_v1.4<br>
Debian release bullseye-5.4.85-imx8mn-v2.0<br>


Some adjustments are necessary for older SOM revisions to ensure the correct CAN controller operation.<br>
Some adjustments are necessary for older SOM revisions to ensure the correct CAN controller operation.<br>
This tutorial shows how to adjust the kernel DTS files for VAR-SOM-MX8M-MINI/NANO revisions 1.0/1.1/1.2.
This tutorial shows how to adjust the kernel DTS files for VAR-SOM-MX8M-MINI/NANO revisions 1.0/1.1/1.2.<br>
<br>
Note that during U-Boot runtime, the ''som_rev'' U-Boot environment variable is updated with the SOM revision.<br>
If you are using several SOM revisions and you'd like to keep a device tree file for both rev.1.3 and rev.1.2/1.1/1.0 in the same SW image, then you can use this variable to automatically choose the correct dtb file for each SOM.


= On VAR-SOM-MX8M-MINI =
= On VAR-SOM-MX8M-MINI =
Line 23: Line 27:
  compatible = "fixed-clock";
  compatible = "fixed-clock";
  #clock-cells = <0>;
  #clock-cells = <0>;
  /* On SOM revisions 1.2 and below the frequency should be 20000000 */
  /* On SOM revions 1.2 and below the frequency should be 20000000 */
- clock-frequency = <40000000>;
- clock-frequency = <40000000>;
+ clock-frequency = <20000000>;
+ clock-frequency = <20000000>;
Line 33: Line 37:
  interrupt-parent = <&gpio1>;
  interrupt-parent = <&gpio1>;
  interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
  interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
- /* On SOM revisions 1.2 and below RX-INT GPIO is not available */
- /* On SOM revions 1.2 and below RX-INT GPIO is not available */
- microchip,rx-int-gpios = <&gpio2 12 GPIO_ACTIVE_LOW>;
- microchip,rx-int-gpios = <&gpio2 12 GPIO_ACTIVE_LOW>;
  /* On SOM revions 1.2 and below the spi-max-frequency should be 10000000 */
  /* On SOM revions 1.2 and below the spi-max-frequency should be 10000000 */
Line 46: Line 50:
  MX8MM_IOMUXC_GPIO1_IO05_GPIO1_IO5 0x16 /* CAN INT */
  MX8MM_IOMUXC_GPIO1_IO05_GPIO1_IO5 0x16 /* CAN INT */
- MX8MM_IOMUXC_SD2_CD_B_GPIO2_IO12 0x16 /* CAN RX-INT - SOM rev1.3+ only */
- MX8MM_IOMUXC_SD2_CD_B_GPIO2_IO12 0x16 /* CAN RX-INT - SOM rev1.3+ only */
- MX8MM_IOMUXC_GPIO1_IO15_GPIO1_IO15 0x16 /* CAN TX-INT - SOM rev1.3+ only */
  >;
  >;
  };
  };
Line 61: Line 64:
  compatible = "fixed-clock";
  compatible = "fixed-clock";
  #clock-cells = <0>;
  #clock-cells = <0>;
  /* On SOM revisions 1.2 and below the frequency should be 20000000 */
  /* On SOM revions 1.2 and below the frequency should be 20000000 */
- clock-frequency = <40000000>;
- clock-frequency = <40000000>;
+ clock-frequency = <20000000>;
+ clock-frequency = <20000000>;
Line 71: Line 74:
  interrupt-parent = <&gpio1>;
  interrupt-parent = <&gpio1>;
  interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
  interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
- /* On SOM revisions 1.2 and below RX-INT GPIO is not available */
- /* On SOM revions 1.2 and below RX-INT GPIO is not available */
- microchip,rx-int-gpios = <&gpio2 12 GPIO_ACTIVE_LOW>;
- microchip,rx-int-gpios = <&gpio2 12 GPIO_ACTIVE_LOW>;
  /* On SOM revisions 1.2 and below the spi-max-frequency should be 10000000 */
  /* On SOM revions 1.2 and below the spi-max-frequency should be 10000000 */
- spi-max-frequency = <20000000>;
- spi-max-frequency = <20000000>;
+ spi-max-frequency = <10000000>;
+ spi-max-frequency = <10000000>;
Line 84: Line 87:
  MX8MN_IOMUXC_GPIO1_IO05_GPIO1_IO5 0x1c0 /* CAN-INT */
  MX8MN_IOMUXC_GPIO1_IO05_GPIO1_IO5 0x1c0 /* CAN-INT */
- MX8MN_IOMUXC_SD2_CD_B_GPIO2_IO12 0x16 /* CAN RX-INT - SOM rev1.3+ only */
- MX8MN_IOMUXC_SD2_CD_B_GPIO2_IO12 0x16 /* CAN RX-INT - SOM rev1.3+ only */
- MX8MN_IOMUXC_GPIO1_IO15_GPIO1_IO15 0x16 /* CAN TX-INT - SOM rev1.3+ only */
  >;
  >;
  };
  };
</syntaxhighlight>
</syntaxhighlight>

Latest revision as of 12:33, 4 April 2021

VAR-SOM-MX8M-MINI/NANO rev. 1.0/1.1/1.2 CAN bus support

Introduction

On VAR-SOM-MX8M-MINI/NANO revision 1.3 some changes were introduced to improve the performance of the MCP251XFD CAN controller.

Starting from the following SW releases the kernel device tree files are synchronized with SOM revision 1.3:
Yocto Dunfell releases dunfell-fslc-5.4-2.1.x-mx8mm-v1.3 & dunfell-fslc-5.4-2.1.x-mx8mn-v1.2
Android 10 releases q10.0.0_1.0.0-ga_dart-mx8mm_v1.6 & android-10.0.0_2.3.0-ga_mx8mn_v1.4
Debian release bullseye-5.4.85-imx8mn-v2.0

Some adjustments are necessary for older SOM revisions to ensure the correct CAN controller operation.
This tutorial shows how to adjust the kernel DTS files for VAR-SOM-MX8M-MINI/NANO revisions 1.0/1.1/1.2.

Note that during U-Boot runtime, the som_rev U-Boot environment variable is updated with the SOM revision.
If you are using several SOM revisions and you'd like to keep a device tree file for both rev.1.3 and rev.1.2/1.1/1.0 in the same SW image, then you can use this variable to automatically choose the correct dtb file for each SOM.

On VAR-SOM-MX8M-MINI

Apply the following patch to imx8mm-var-som.dtsi: 

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi
index 9f648ebff447..9f60caecd7ce 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi
@@ -14,7 +14,7 @@
 		compatible = "fixed-clock";
 		#clock-cells = <0>;
 		/* On SOM revions 1.2 and below the frequency should be 20000000 */
-		clock-frequency = <40000000>;
+		clock-frequency = <20000000>;
 		clock-output-names = "can_osc";
 	};
 
@@ -114,10 +114,8 @@
 		clocks = <&can0_osc>;
 		interrupt-parent = <&gpio1>;
 		interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
-		/* On SOM revions 1.2 and below RX-INT GPIO is not available */
-		microchip,rx-int-gpios = <&gpio2 12 GPIO_ACTIVE_LOW>;
 		/* On SOM revions 1.2 and below the spi-max-frequency should be 10000000 */
-		spi-max-frequency = <20000000>;
+		spi-max-frequency = <10000000>;
 		status = "okay";
 	};
 
@@ -172,8 +170,6 @@
 	pinctrl_can: cangrp {
 		fsl,pins = <
 			MX8MM_IOMUXC_GPIO1_IO05_GPIO1_IO5		0x16 	/* CAN INT */
-			MX8MM_IOMUXC_SD2_CD_B_GPIO2_IO12		0x16	/* CAN RX-INT - SOM rev1.3+ only */
 		>;
 	};

On VAR-SOM-MX8M-NANO

Apply the following patch to imx8mn-var-som.dtsi: 

diff --git a/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
index 66d7b020b857..6af877e6aa8f 100644
--- a/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
@@ -14,7 +14,7 @@
 		compatible = "fixed-clock";
 		#clock-cells = <0>;
 		/* On SOM revions 1.2 and below the frequency should be 20000000 */
-		clock-frequency = <40000000>;
+		clock-frequency = <20000000>;
 		clock-output-names = "can_osc";
 	};
 
@@ -124,10 +124,8 @@
 		clocks = <&can0_osc>;
 		interrupt-parent = <&gpio1>;
 		interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
-		/* On SOM revions 1.2 and below RX-INT GPIO is not available */
-		microchip,rx-int-gpios = <&gpio2 12 GPIO_ACTIVE_LOW>;
 		/* On SOM revions 1.2 and below the spi-max-frequency should be 10000000 */
-		spi-max-frequency = <20000000>;
+		spi-max-frequency = <10000000>;
 		status = "okay";
 	};
 
@@ -193,8 +191,6 @@
 	pinctrl_can: cangrp {
 		fsl,pins = <
 			MX8MN_IOMUXC_GPIO1_IO05_GPIO1_IO5		0x1c0	/* CAN-INT */
-			MX8MN_IOMUXC_SD2_CD_B_GPIO2_IO12		0x16	/* CAN RX-INT - SOM rev1.3+ only */
 		>;
 	};
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This page was last edited on 4 April 2021, at 12:33.

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