Hello,
We have designed a custom board using the i.MX6UL that will have three CAN buses. I'm using flexcan for the first two CAN buses, and using the Microchip MCP2515 via SPI on the thrird CAN bus. I'm using kernel 4.1.15. I have added the MCP251X driver to the kernel, but the driver is never loaded. The only output from dmesg says the following:
# dmesg | grep spi
[ 0.437217] spi_imx 2010000.ecspi: probed
If I add a spidev node, it will load but not the driver for the MCP2515. Could u-boot be doing something to the pins that would mess up spi in the kernel? My device tree is found below... any ideas why this is not working?
clocks {
mcp251x_clock: mcp251x_clock {
compatible = "fixed-clock";
reg = <1>;
#clock-cells = <0>;
clock-frequency = <8000000>;
clock-output-names = "mcp251x_clock";
};
};
&ecspi3 {
fsl,spi-num-chipselects = <1>;
cs-gpios = <&gpio4 12 1>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi3>;
status = "okay";
/* spidev@0x00 {
compatible = "spidev";
spi-max-frequency = <10000000>;
reg = <0>;
};*/
can0: mcp2515@0 {
compatible = "microchip,mcp2515";
reg = <0>;
clocks = <&mcp251x_clock>;
interrupt-parent = <&gpio4>;
interrupts = <11 0x2>;
spi-max-frequency = <10000000>;
xceiver-supply = <®_can_3v3>;
vdd-supply = <®_can_3v3>;
status = "okay";
};
};
/**iomuxc**/
pinctrl_ecspi3: ecspi3grp {
fsl,pins = <
MX6UL_PAD_NAND_CLE__ECSPI3_MISO 0x100B1
MX6UL_PAD_NAND_CE1_B__ECSPI3_MOSI 0x100B1
MX6UL_PAD_NAND_CE0_B__ECSPI3_SCLK 0x100B1
MX6UL_PAD_NAND_WP_B__ECSPI3_RDY 0x100B1
/*MX6UL_PAD_NAND_READY_B__ECSPI3_SS0 0x100B1*/
MX6UL_PAD_NAND_READY_B__GPIO4_IO12 0x000B1
>;
};
The oscilloscope reads that I'm sending 0x0E, which according to the mcp251x.c driver, is correct (it's the very first thing that the driver transmits). I updated the driver to match the latest version in the mainline kernel, and here is what I get from dmesg:
[ 0.444582] spi_imx 2010000.ecspi: probed
[ 0.457894] mcp251x spi2.0: Cannot initialize MCP2515. Wrong wiring?
[ 0.463077] mcp251x spi2.0: Probe failed, err=19
The issue is MISO never moves. I've tried different MCP2515 chips, but nothing seems to ever come out of the chip. Does my device tree and schematic look correct? Anything else it may be?
