[PATCH v2 09/11] arm/dst: Add Aspeed ast2500 device tree

Xo Wang xow at google.com
Thu May 5 16:11:53 PDT 2016


Joel Stanley <joel <at> jms.id.au> writes:
> +/ {
> +	model = "AST2500 EVB";
> +	compatible = "aspeed,ast2500";
> +
> +	chosen {
> +		stdout-path = &uart5;
> +		bootargs = "console=ttyS4,115200";
> +	};
> +
> +	memory {
> +		reg = < 0x80000000 0x10000000 >;

The AST2500 EVB has an SK Hynix H5AN4G6NMFR 4Gb part, so this should be 
0x20000000 for size.

> +			uart1: serial <at> 1e783000 {
> +				compatible = "ns16550a";
> +				reg = <0x1e783000 0x1000>;
> +				reg-shift = <2>;
> +				interrupts = <9>;
> +				clock-frequency = <1843200>;

The AST2500 datasheet 39.3.1 states the input clock to their 16550 IP is 
24 MHz. Their u-boot code also has #define CONFIG_SYS_NS16550_CLK 
24000000. I suspect we hit a path in the serial/8250 driver that doesn't 
change the divisor from what u-boot set, which is why this has worked.

Thanks for the porting work!

cheers
//xo





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