SD-Card driver modification for Zynq questions

[Thomas Skibo]

> On Sep 28, 2016, at 2:00 PM, Oleksandr Tymoshenko <gonzo at bluezbox.com> wrote:
> 
> 
>> On Sep 28, 2016, at 7:16 AM, Thomas Skibo via freebsd-arm <freebsd-arm at freebsd.org> wrote:
>> 
>> 
>> Why not just set max-frequency to 200Mhz in the DTS file entry?
> 
> From quick glance it’s not going to help. Slot’s max_clk is set to that value but then it’s
> overwritten in sdhci_init_slot by value obtained from register.  We need to fix it and also
> add tunable for non-fdt systems.   

I checked the Zynq manual and it looks like it doesn’t provide a frequency in the capabilities register so sdhci_init_slot() won’t change the slot’s max_clk.