[RFC][PATCH] MPC832x_RDB: update dts to use spi, register mmc_spi stub
Segher Boessenkool
segher at kernel.crashing.org
Wed Aug 1 08:06:46 EST 2007
>>> spi at 4c0 {
>>> device_type = "spi";
>>> + device-id = <1>;
>>
>> Can we just use the reg value for bus_num in the kernel.
>
> Sure, technically nothing prevents this. But, QE specs names
> SPIs by these ids.
As a minimum the property name should start with "fsl," then.
> Plus, from the kernel side spi name will be
> not pretty, it will be spi1216.1.
What, the kernel cannot implement a counter itself?
>>> + max-chipselect = <1>;
>>
>> I'm not sure how I feel about this in here, I'm thinking it should go.
>
> It's board-specific, i.e. how much chips connected to this SPI bus.
It is misnamed then. It should be automatically derived from
the child nodes, though.
>>> + mmc at 01 {
@01 should be @1. Except that it is wrong, since there is
no "reg" property.
>>> + device_type = "mmc";
No device_type please.
>>> + compatible = "mmc-spi";
Needs to be more specific.
>>> + device-id = <1>;
Get rid of this.
>>> + max-speed-hz = <bebc20>; /* 12500000 Hz */
Just max-speed.
>>> + chip-select = <0>;
This should be named "reg". And the parent needs #address-cells
and #size-cells properties.
>>> + pio-handle = <&mmc1pio>;
What is this for?
>> we should do this in board code and not the device tree.
>
> Well, I've done this initially. But Vitaly hinted that this could
> be done in the DT instead, which made sense to me - mmc is the child
> device of SPI bus. Why do you think it shouldn't be in the DT? I'm
> not arguing, just want understand this.
The hardware should be described in the device tree. This isn't
the same as simply copying all your Linux code into it ;-)
Segher
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