Zynq MMC/SD controller with Linux Kernel 3.12.x and later.

Just a quick note regarding Zynq SD card controller support in Linux Kernel 3.13.x and later. Apparently, Xilinx used industry standard IP blocks for Zynq PS hardware, including SDHC controller. And now they are switching away from 'custom' drivers. For example, Xilinx Zynq PS I2C now called 'Cadence I2C Controller' and new name for Zynq SDHC controller is 'Arasan'.

To make SD card work again with latest kernels, we need to select appropriate option during Linux kernel configuration and make changes for 'ps7_sd_0' and/or 'ps7_sd_1' in devices tree file(DTS). Arasan driver also looking for different 'clock-names'.

Below SD controller section of my DTS file for ZedBoard:

ps7_sd_0: ps7-sdio@e0100000 {
	clock-frequency = <50000000>;
	clock-names = "clk_xin", "clk_ahb";
	clocks = <&clkc 21>, <&clkc 32>;
	compatible = "arasan, sdhci-8.9a";
	interrupt-parent = <&ps7_scugic_0>;
	interrupts = <0 24 4>;
	reg = <0xe0100000 0x1000>;
	xlnx,has-cd = <0x1>;
	xlnx,has-power = <0x0>;
	xlnx,has-wp = <0x1>;
} ;

zynq12_001

Tagged with: , , , , , , ,

Leave a Reply