Hi All,
I 'm trying to use MCP2515 CAN extension board from waveshare on Jetson nano, I found some dts files ref to GitHub - Seeed-Studio/seeed-linux-dtoverlays: Device Tree Overlays for Seeed boards
with some modification, my latest dts file is like below:
// SPDX-License-Identifier: GPL-2.0-only
/*
* Jetson Device-tree overlay for
* MCP2515
*
* Copyright (c) 2020 Seeed Technology Co,Ltd - https://www.seeed.cc.
* All rights reserved.
*
*/
/dts-v1/;
/plugin/;
#include <dt-bindings/pinctrl/pinctrl-tegra.h>
#include <dt-bindings/gpio/tegra-gpio.h>
/ {
overlay-name = "MCP251x CAN Controller";
jetson-header-name = "Jetson 40pin Header";
compatible = "nvidia,p3449-0000-b00+p3448-0000-b00\0nvidia,p3449-0000-a02+p3448-0000-a02";
fragment@0 {
target-path = "/";
__overlay__ {
clocks {
can_clock: can_clock {
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <8000000>;
clock-accuracy = <100>;
};
};
};
};
fragment@1 {
target = <&spi0>;
__overlay__ {
#address-cells = <1>;
#size-cells = <0>;
spi@0 {
status = "okay";
compatible = "microchip,mcp2515";
reg = <0x0>;
spi-max-frequency = <10000000>;
nvidia,enable-hw-based-cs;
nvidia,rx-clk-tap-delay = <0x7>;
clocks = <&can_clock>;
interrupt-parent = <&gpio>;
interrupts = <TEGRA_GPIO(S, 5) 0x1>;
controller-data {
nvidia,cs-setup-clk-count = <0x1e>;
nvidia,cs-hold-clk-count = <0x1e>;
nvidia,rx-clk-tap-delay = <0x1f>;
nvidia,tx-clk-tap-delay = <0x0>;
};
};
spi@1 {
status = "disabled";
};
};
};
fragment@2 {
target = <&spi1>;
__overlay__ {
#address-cells = <1>;
#size-cells = <0>;
spi@0 {
status = "disabled";
};
spi@1 {
status = "okay";
compatible = "microchip,mcp2515";
reg = <0x0>;
spi-max-frequency = <10000000>;
nvidia,enable-hw-based-cs;
nvidia,rx-clk-tap-delay = <0x7>;
clocks = <&can_clock>;
interrupt-parent = <&gpio>;
interrupts = <TEGRA_GPIO(V, 0) 0x1>;
controller-data {
nvidia,cs-setup-clk-count = <0x1e>;
nvidia,cs-hold-clk-count = <0x1e>;
nvidia,rx-clk-tap-delay = <0x1f>;
nvidia,tx-clk-tap-delay = <0x0>;
};
};
};
};
fragment@3 {
target = <&pinmux>;
__overlay__ {
pinctrl-names = "default";
pinctrl-0 = <&jetson_io_pinmux>;
jetson_io_pinmux: exp-header-pinmux {
hdr40-pin19 {
nvidia,pins = "spi1_mosi_pc0";
nvidia,function = "spi1";
nvidia,pull = <TEGRA_PIN_PULL_DOWN>;
nvidia,tristate = <TEGRA_PIN_DISABLE>;
nvidia,enable-input = <TEGRA_PIN_ENABLE>;
};
hdr40-pin21 {
nvidia,pins = "spi1_miso_pc1";
nvidia,function = "spi1";
nvidia,pull = <TEGRA_PIN_PULL_DOWN>;
nvidia,tristate = <TEGRA_PIN_DISABLE>;
nvidia,enable-input = <TEGRA_PIN_ENABLE>;
};
hdr40-pin23 {
nvidia,pins = "spi1_sck_pc2";
nvidia,function = "spi1";
nvidia,pull = <TEGRA_PIN_PULL_DOWN>;
nvidia,tristate = <TEGRA_PIN_DISABLE>;
nvidia,enable-input = <TEGRA_PIN_ENABLE>;
};
hdr40-pin24 {
nvidia,pins = "spi1_cs0_pc3";
nvidia,function = "spi1";
nvidia,pull = <TEGRA_PIN_PULL_UP>;
nvidia,tristate = <TEGRA_PIN_DISABLE>;
nvidia,enable-input = <TEGRA_PIN_ENABLE>;
};
hdr40-pin37 {
nvidia,pins = "spi2_mosi_pb4";
nvidia,function = "spi2";
nvidia,pull = <TEGRA_PIN_PULL_DOWN>;
nvidia,tristate = <TEGRA_PIN_DISABLE>;
nvidia,enable-input = <TEGRA_PIN_ENABLE>;
};
hdr40-pin22 {
nvidia,pins = "spi2_miso_pb5";
nvidia,function = "spi2";
nvidia,pull = <TEGRA_PIN_PULL_DOWN>;
nvidia,tristate = <TEGRA_PIN_DISABLE>;
nvidia,enable-input = <TEGRA_PIN_ENABLE>;
};
hdr40-pin13 {
nvidia,pins = "spi2_sck_pb6";
nvidia,function = "spi2";
nvidia,pull = <TEGRA_PIN_PULL_DOWN>;
nvidia,tristate = <TEGRA_PIN_DISABLE>;
nvidia,enable-input = <TEGRA_PIN_ENABLE>;
};
hdr40-pin18 {
nvidia,pins = "spi2_cs0_pb7";
nvidia,function = "spi2";
nvidia,pull = <TEGRA_PIN_PULL_UP>;
nvidia,tristate = <TEGRA_PIN_DISABLE>;
nvidia,enable-input = <TEGRA_PIN_ENABLE>;
};
};
};
};
};
Now the issue is I can only send at most 8 CAN message out from the jetson, but the receive is seems much better, you can see below picture, I connect Jetson with a VN1640 device from Vector, in the picture TX is from Canalyzer software, which is the PC, and RX is from jetson nano,
I send a lot of can message via command, “cansend can0 132#ACBA”, as you can see only first one is send out, only after the PC send another CAN message, the Jetson start send the CAN message in the buffer
and sometimes we even see “Staff error”,
Any suggestions for this issue, thanks!
