i.MX6DL can调试

Wonderself · 发表于 2016-3-30 15:10:06

i.MX6dl Linux平台，BSP版本fsl-yocto-3.14.28-1.0.0
目前遇到的问题是can1可以使能，但发送数据时TX始终高电平，使用loopback模式接收不到，论坛FAE能否帮我看下？谢谢了！
以下是执行过程
root@imx6dlsabresd:~# ip link set can0 down
ansend can0 123#11223344556677root@imx6dlsabresd:~# ip link set can0 type can bitrate 125000 loopback on
root@imx6dlsabresd:~# ip link set can0 up
flexcan 2090000.can can0: writing ctrl=0x0e313005
root@imx6dlsabresd:~# candump can0 &
[1] 959
root@imx6dlsabresd:~# cansend can0 123#11223344556677
root@imx6dlsabresd:~# ip -details -statistics link show can0
2: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN mode DEFAULT group default qlen 10
link/can  promiscuity 0
can <LOOPBACK> state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0
   bitrate 125000 sample-point 0.875
   tq 500 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
   flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1
   clock 30000000
   re-started bus-errors arbit-lost error-warn error-pass bus-off
   0       0       0       0       0       0
RX: bytes  packets  errors  dropped overrun mcast
0       0       0    0    0    0
TX: bytes  packets  errors  dropped carrier collsns
8       1       0    0    0    0

我知道答案目前已有9人回答

阅读全文

Wonderself · 发表于 2016-3-30 15:10:59

这是imx6qdl-sabresd.dtsi的配置
+             pinctrl_flexcan1: flexcan1grp {
+                      fsl,pins = <
+                            MX6QDL_PAD_KEY_ROW2__FLEXCAN1_RX       0x80000000
+                            MX6QDL_PAD_KEY_COL2__FLEXCAN1_TX       0x80000000
+                      >;
+             };
+             pinctrl_flexcan2: flexcan2grp {
+                      fsl,pins = <
+                            MX6QDL_PAD_KEY_ROW4__FLEXCAN2_RX       0x80000000
+                            MX6QDL_PAD_KEY_COL4__FLEXCAN2_TX       0x80000000
+                      >;
+             };
@@ -790,6 +804,17 @@
      fsl,wdog-reset = <2>;
};

+&flexcan1 {
+    pinctrl-names = "default";
+    pinctrl-0 = <&pinctrl_flexcan1>;
+    status = "okay"; /* pin conflict with fec */
+};
+&flexcan2 {
+    pinctrl-names = "default";
+    pinctrl-0 = <&pinctrl_flexcan2>;
+    status = "okay"; /* pin conflict with fec */
+};

附件是原理图

Wonderself · 发表于 2016-3-30 15:11:20

1，loopback模式下can1的TX、RX是否需要短接？

2，cmdline传的是can1，为什么设置波特率仍然操作的是can0?
root@imx6dlsabresd:~# ip link set can0 up
flexcan 2090000.can can0: writing ctrl=0x0e313005

3,我是把J4001的79管脚引出来量的，发数据时始终高电平，是哪里还需要配置吗？