topic Re: Imx233 spi speed - Mainline Kernel in i.MX Processors

Imx233 spi speed - Mainline Kernel

pierreparent — Fri, 22 May 2015 12:22:20 GMT

Hi,

I don't succeed in configuring SPI Hz-Speed with mailine kernel (4.0.3).

Here is my dts:

		ssp1: ssp@80034000 {
			#address-cells = <1>;
			#size-cells = <0>;
			compatible = "fsl,imx23-spi";
			pinctrl-names = "default";
			pinctrl-0 = <&spi2_pins_a>;
			status = "okay";
			clock-frequency = <5000000>;

spidev: spidev@0 {
		compatible = "spidev";
	spi-max-frequency = <5000000>;
	reg = <0>;
	};

};

But whatever I tried the spi_clock remains at 1mhz!

Does anyone know how to solve this problem?

Thanks in advance,

Pierre.

Re: Imx233 spi speed - Mainline Kernel

pierreparent — Fri, 22 May 2015 13:48:40 GMT

I think it comes form the function void mxs_ssp_set_clk_rate(struct mxs_ssp *ssp, unsigned int rate) in file clk-ssp.c which should change clock speed but does not work, I don't know why yet.

Re: Imx233 spi speed - Mainline Kernel

b36401 — Wed, 27 May 2015 08:26:40 GMT

You can change fuses for SSP clock according to table 7-53 "HW_OCOTP_ROM0" of i.MX23 Reference Manual.

11:8 - SSP_SCK_INDEX Index to SSP clock speed.

0000 = 240kHz

0010 = 1MHz 0011 = 2MHz

0100 = 4 MHz 0101 = 6MHz

0110 = 8MHz 0111 = 10MHz

1000 = 12MHz 1001 = 16MHz

1010 = 20MHz 1011 = 24MHz

1100 = 40MHz 1101 = 48MHz

1110 = 240kHz

Have a great day,

Victor

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