Hi Guys!
This is my fist post on this forum. I have been spending a lot of time these days to make the MCP2515 CAN Controller on the RISCV computer, but I am not able to make it work even if everything seems to be on place. It is obvious that I am not understanding something correclty and that is why is not working. I am using the MangoPi Mqpro that has the SPI port on the 40 pin connector.
Right now is not possible to add overlays on mangopi with the arbiam, but I managed to upload my custom overlays using the grub and Ubuntu, that part is not relevant for the topic. Let's assume for the topic that I am able to upload overlays and they are correctly applied on device tree.
### Connections
The SPI interface is defined as follows, extracted from /sys/kernel/debug/pinctrl/2000000.pinctrl/pinmux-pins:
pin 106 (PD10): device 4026000.spi function spi1 group PD10
pin 107 (PD11): device 4026000.spi function spi1 group PD11
pin 108 (PD12): device 4026000.spi function spi1 group PD12
pin 109 (PD13): device 4026000.spi function spi1 group PD13
pin 110 (PD14): device 4026000.spi function spi1 group PD14
pin 111 (PD15): device 4026000.spi function spi1 group PD15
pin 112 (PD16): device 2000c00.pwm function pwm group PD16
pin 113 (PD17): device spi1.0 function irq group PD17
Basically is connected to the SPI interface of the MCP2515, and the interrupt is connected to PD17.
SPI_INT
PD17
SPI_SCK
PD11
SPI_SI
PD12
SPI_SO
PD13
SPI_CS
PD10
The overlay that I am applying is the next one:
/dts-v1/;
/plugin/;
/ {
compatible = "allwinner,d1-nezha\0allwinner,sun20i-d1";
fragment@0 {
target-path = "/clocks";
__overlay__ {
#address-cells = <1>;
#size-cells = <1>;
/* External crystal oscillator on the board */
can0_osc_fixed: can0_osc_fixed {
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <8000000>;
phandle = <0x81>;
};
};
};
fragment@1 {
target = <&pinctrl>; // pinctrl@2000000
__overlay__ {
can0_pin_irq: can0_pin_irq {
pins = "PD17";
function = "irq";
phandle = <0x85>;
};
};
};
fragment@2 {
target = <&spi>; //spi@4026000
__overlay__ {
#address-cells = <1>;
#size-cells = <0>;
status = "okay";
mcp2515 {
reg = <0>; // SPI 1
compatible = "microchip,mcp2515";
pinctrl-names = "default";
pinctrl-0 = <0x85>;
spi-max-frequency = <10000000>;
interrupt-parent = <0x22>; // pinctrl@2000000
interrupts = <0 113 2>; // IRQ LINE, try with <0 65 2>
clocks = <0x81>;
status = "okay";
};
};
};
};
However when I boot up I look to the interrupts and there is nothing related to the irq line for the CAN/spi, output of /proc/interrupts:
CPU0
2: 79503 sun20i-intc 75 Edge timer@2050000
3: 0 sun20i-intc 109 Edge 5500000.hdmi, dw-hdmi-cec
4: 0 sun20i-intc 25 Edge mv64xxx_i2c
5: 0 RISC-V INTC 5 Edge riscv-timer
6: 14 sun20i-intc 68 Edge sun8i-ce-ns
7: 0 sun20i-intc 47 Edge ohci_hcd:usb3
74: 0 sun20i-intc 31 Edge sun6i-spi
78: 5926 sun20i-intc 74 Edge ths
79: 0 sun20i-intc 50 Edge ohci_hcd:usb4
80: 0 sun20i-intc 46 Edge ehci_hcd:usb1
81: 1336 sun20i-intc 18 Edge ttyS1
82: 189890 sun20i-intc 57 Edge sunxi-mmc
83: 0 sun20i-intc 82 Edge 1c0e000.video-codec
84: 0 sun20i-intc 80 Edge 2010000.iommu
85: 0 sun20i-intc 107 Edge 5470000.lcd-controller
88: 0 sun20i-intc 49 Edge ehci_hcd:usb2
89: 0 sun20i-intc 160 Edge 7090000.rtc
90: 2 sun20i-intc 27 Edge mv64xxx_i2c
98: 0 sun20i-intc 45 Edge musb-hdrc.2.auto
101: 8630 sun20i-intc 56 Edge sunxi-mmc
109: 0 sun20i-intc 66 Edge 3002000.dma-controller
111: 4 sun20i-intc 32 Edge sun6i-spi
112: 0 sun20i-intc 77 Edge sun4i-a10-lradc-keys
113: 0 sun20i-intc 106 Edge 5461000.lcd-controller
114: 7 sun20i-intc 167 Edge sunxi-ir
119: 0 sun20i-intc 36 Edge 2008000.led-controller
204: 1 sunxi_pio_edge 84 Edge usb0-vbus-det
205: 1 sunxi_pio_edge 85 Edge usb0-id-det
254: 1 sunxi_pio_edge 134 Edge 4020000.mmc cd
IPI0: 0 Rescheduling interrupts
IPI1: 0 Function call interrupts
IPI2: 0 CPU stop interrupts
IPI3: 0 IRQ work interrupts
IPI4: 0 Timer broadcast interrupts
Some outputs from the Kernel:
[ 52.133406] CAN device driver interface
[ 52.918270] mcp251x spi1.0 can0: MCP2515 successfully initialized.
[ 1163.417322] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready
[ 1182.919088] can: controller area network core
[ 1182.919249] NET: Registered PF_CAN protocol family
[ 1183.000429] can: raw protocol
And after booting I run the next:
$ sudo ip link set can0 up type can bitrate 500000
$ sudo ifconfig can0 up
$ sudo cansend can0 5A1#00.01.02.03.04
This configuration is not working because when I try to connect, I am not receiving anything.
I suppose that I am not configuring correctly the interrupt line of the IRQ of SPI. My knowledge on this is very narrow, and I am not able to understand what is failing. All the feedback is totally welcome. I can give more documentation if my explanation is not complete enought.
Thanks!
