Re: [PATCH v6 02/11] ARM: dts: renesas: r8a7740: Add clocks for FSI

[Bui Duc Phuc]

Hi Geert,


>
> According to my schematics (RevA), R120 is not populated, but R250 is.
> So the 12.288 MHz clock is fed to both the FSIACK-pin of R-Mobile A1,
> and the MCLK-pin of the WM8978 codec.
> Which revision of the schematics and board do you have?
>

Oh, sorry, I misread it. You're right, mine is also Rev A, and R120 is
not populated, but R250 is.

>
> I haven't located R120 and R250 yet, so I don't know which
> configuration my board has.
>

Please flip the board over; these resistors are located on the bottom
side of the board rather than the top.
Other components like R123, R124, R139, and R227 are on the top side,
but they are only visible after removing the display.

>
> That information is found in the R-Mobile A1 docs (PORT11):
>
> Table 1.3 Pin Assignment (505-Pin BGA Package)
>     Ball No. / Pin Name / Multiplexed Pin Functions / GPIO
>     G3 / FSIACK / FSIACK/FSIBCK / PORT11
>
> Table 54.1 List of Multiplexed Pins
>     Pin Name / Function 0 / Function 1 / Function 2
>     FSIACK / PORT11 / FSIACK / FSIBCK
>

It would be helpful if there were a more detailed Armadillo schematic available.
The R-Mobile A1 documentation (PORT11) is generic and shared across
multiple boards,
so it does not necessarily reflect the exact wiring used on Armadillo.

I did look at the board support code and pin configuration some time
ago, and I also tested audio output over HDMI successfully.
As far as I remember, these pins can be configured as either inputs or
outputs. For example:

fsia_pins: sounda {
    groups = "fsia_sclk_in", "fsia_mclk_out",
         "fsia_data_in_1", "fsia_data_out_0";
    function = "fsia";
};

I'll take another look at it when I have some time next week.
At the moment I'm busy working on a few ASoC cleanup patches,
so I haven't had a chance to investigate this further.

Best regards,
Phuc