Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master

[Jeremy Kerr <jk@ozlabs.org>]

Hi Chris,

>From this:

>> +
>> +The standard FSI master node
>> +----------------------------
>> +This node describes a FSI master implmemented fully in hardware
>> +with dedicated input/output pins required for its function (i.e.
>> +not using generic GPIO pins).
>> +Required property:
>> +	compatible = "ibm,fsi-master"

and this:

>> +Example:
>> +
>> +fsi-master {
>> +	compatible = "ibm,fsi-master-gpio", "ibm,fsi-master";
> 
> From the description, these should be mutually exclusive.

I agree with Rob here. The intention is for "ibm,fsi-master" to be an
abstract master -- simply indicating that this node describes a master,
with no specific implementation, and "ibm,fsi-master-gpio" to be a
GPIO-based implementation. A hardware-based FSI master would have a
different compatible value, based on the hardware.

We should remove references to implementations in the "The standard FSI
master node" section, because this is independent of implementation.

>> +	clk-gpios = <&gpio 0>, <&gpio 6>;
>> +	data-gpios = <&gpio 1>, <&gpio 7>;
>> +	enable-gpios = <&gpio 2>, <&gpio 8>;
>> +	trans-gpios = <&gpio 3>, <&gpio 9>;
>> +	mux-gpios = <&gpio 4>, <&gpio 10>;

Do we support multiple-link masters? This example implies a 2-link
master.

Cheers,


Jeremy