[U-Boot] [PATCH 07/20] dm: tegra: cros_ec: Enable Chrome OS EC on Nyan-big

Simon Glass
2015-03-29T13:00:44Z

Hi Stephen,

On 25 February 2015 at 16:15, Stephen Warren <swarren@wwwdotorg.org> wrote:
> On 02/17/2015 03:29 PM, Simon Glass wrote:
>>
>> Enable the EC and keyboard, using the SPI bus.
>>
>> The EC driver requires a particular format and a deactivation delay. Also
>> U-Boot does not support interrupts.
>>
>> For now, adjust the device tree to comply. At some point we should tidy
>> this up to support interrupts and make tegra and exynos use the same
>> setup.
>
>
>> diff --git a/arch/arm/dts/tegra124-nyan-big.dts
>> b/arch/arm/dts/tegra124-nyan-big.dts
>
>
>> spi at 7000d400 {
>> status = "okay";
>> + spi-deactivate-delay = <200>;
>> + spi-max-frequency = <3000000>;
>>
>> cros_ec: cros-ec at 0 {
>> - compatible = "google,cros-ec-spi";
>> - spi-max-frequency = <3000000>;
>> + compatible = "google,cros-ec";
>
>
> I recall some discussion that implied both the SPI bus/controller node and
> the SPI device node both needed an spi-max-frequency property. Can you
> double-check this change conforms with the DT binding, and whatever Linux
> has in its DT files?

It looks like it needs to be in the slave so I'll add it back there. I
don't see it in the bus in the Linux version of the SPI bus node, so
presumably it uses a default speed, perhaps higher than 3MHz. Probably
best to have it in both places.

Regards,
Simon