[PATCH linux v2 17/17] drivers/fsi: Add GPIO master functionality

[Christopher Bostic]

On Sun, Oct 9, 2016 at 7:56 PM, Jeremy Kerr <jk at ozlabs.org> wrote:
> Hi Chris,
>
>> Add setup of the GPIO pins for FSI master function.
>> Set up I/O directions, define all pins needed and
>> set up their initial values.  Define serial out
>> operation.
>>
>> Signed-off-by: Chris Bostic <cbostic at us.ibm.com>
>
> Awesome! I assume this is still in development though, right?
>

Yes its not complete as it stands in this set.  I'll put the remainder
in version 3
of this set

>>  struct fsi_master_gpio {
>>       struct fsi_master       master;
>>       struct gpio_desc        *gpio_clk;
>>       struct gpio_desc        *gpio_data;
>> +     struct gpio_desc        *gpio_trans;            /* Voltage translator */
>> +     struct gpio_desc        *gpio_enable;           /* FSI enable */
>> +     struct gpio_desc        *gpio_mux;              /* Mux control */
>>  };
>
> OK, you should update the device-tree binding to include these extra

> GPIOs (and put their descriptions in there). Are they required for all
> implementations? (is it possible that some would only have clock and
> data?)
>

OK Will update the dev-tree binding.

Good question about other implementations.  It is possible that they could have
only clock and data.  I suspect some type of enable should be used but
it wouldn't be strictly necessary.  What would you suggest given the potential
for pin differences between platforms?

Thanks,
Chris

> Cheers,
>
>
> Jeremy