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We are integrating the TCAN4550 into our system.
Initialize the SPI directly after powered on, and then perform the read operation.
The SPI communications is working. But SDO can't receive any data like below chart:
DTS config:
&spi2 {
status = "okay";
max-freq = <50000000>;
cs-gpios = <&gpio2 RK_PB4 GPIO_ACTIVE_LOW>;
tcan4x5x: tcan4x5x@0 {
compatible = "ti,tcan4x5x";
reg = <0>;
#address-cells = <1>;
#size-cells = <1>;
spi-max-frequency = <10000000>;
clock-names = "cclk", "hclk";
clocks = <&tcan4x5x_cclk>, <&tcan4x5x_hclk>;
bosch,mram-cfg = <0x0 2 1 4 5 0 3 10>;
pinctrl-names = "default";
pinctrl-0 = <&pwr_en>, <&data_ready>;
pwr_en-gpios = <&gpio2 RK_PA2 GPIO_ACTIVE_HIGH>; /* GPIO2_A2 */
data-ready-gpios = <&gpio2 RK_PB0 GPIO_ACTIVE_LOW>; /* GPIO2_B0 */
status = "okay";
};
};
&pinctrl {
tcan4x5x {
pwr_en: pwr-en {
rockchip,pins = <2 RK_PA2 RK_FUNC_GPIO &pcfg_pull_up>;
};
data_ready: data-ready {
rockchip,pins = <2 RK_PB0 RK_FUNC_GPIO &pcfg_pull_up>;
};
};
};
Hi Jonathan,
We adjusted SPI driver to transmit MSB first, but MISO still get 0xff
And I have another question, is that necessary need to control the RST pin?
Hi Nick,
Ok. In addition to checking the RST to make sure it is low, can you also verify the VIO pin has the correct voltage on it and that there is a valid clock on the OSC1/2 pins?
I noticed in the schematic that there was 2 different net names for the net connected to the VIO pin. The layout tool will have to pick one of the net names to use, but I wanted to make sure that it still got connected on the board to the 3V3 supply. VIO is needed for the SPI and clock circuitry to function.
The digital core also needs a clock in order to write and read the register values, so just verify you see an oscillating clock on the OSC1/2 pins. If the clock is not functioning, the SPI won't return a value for most of the registers. The registers 0x0000 to 0x0010 are implemented in logic and do not require the OSC1/2 clock to be functional and only requires the SPI clock to return a value. You can also try reading the Device ID registers 0x0000 and 0x0004 to help detect a possible clocking issue.
Regards,
Jonathan
