[U-Boot] [RFC 0/2] Add cdns-i2c driver as drop in for zynq-i2c

Michal Simek
2016-01-06T07:53:12Z

On 5.1.2016 18:30, Moritz Fischer wrote:
> Hi Michal,
>
> On Tue, Jan 5, 2016 at 7:44 AM, Michal Simek <michal.simek@xilinx.com> wrote:
>
>> I have looked at these patches and I don't know why there is 100k
>> limitation in cdns_i2c_set_bus_speed. DTS is using 400k in Linux without
>> any problem.
>
> Well I could statically calculate the values for 400K, too but anyway that works
> only if your CPU_CLK_1X is 111MHz. Is there a way to figure out the CPU_CLK_1X
> frequency?

Check the clock driver.

>> Unfortunately I found that i2c muxes like pca9548 are not supported yet
>> but I have create sort of skeleton for that but it looks like that there
>> is no standard binding where i2c-parent is required. Also every muxes
>> bus needs to have correct label and alias.
>
> Yeah, I realized that last night when I started playing around with
> it. I was trying
> to pull in the linux one but didn't get around to finish that yet.

It is simple to create that mux drivers but I am scared about that need
for aliases and also i2c-parent has to go out of mux class too.
I see that it is used in the mainline kernel but it has be changed.

>> Also I have found that there is eeprom dependency which needs to be
>> resolved to be able to use this driver instead of old one.
>
> Yeah I realized that. Do any of the zynq boards actually use CMD_EEPROM?

We have a code for zc702 to save internal variables to EEPROM. zc706
should have that memory too.

Thanks,
Michal