Hi Ulrich,
On Thu, Jun 30, 2016 at 3:15 PM, Ulrich Hecht
<[email protected]> wrote:
> This is a setup I have cooked up to check if talking to SD cards via MSIOF1
> and SPI works. It works by taking the SD2 lines off the bus by defining
> them as GPIO inputs and jumpering the MSIOF pins to SD card slot 2 via EXIO
> connectors like so:
>
> EXIO_A pin EXIO_B pin
> 19 (MSIOF1_SCK_3) 3 (SD2_CLK_3)
> 31 (MSIOF1_TXD_3) 5 (SD2_CMD_3)
> 33 (MSIOF1_RXD_3) 13 (SD2_DAT0_3)
>
> (Credits for the idea go to Mr. Damm.)
>
> It works when defining an spi-gpio device, but it does not work with the
> MSIOF IP; any attempt to read from the SD card returns all zeros.
>
> Does anybody see any obvious issue there? Did I forget anything in the
> msiof1 node?
At first sight, I don't see anything that is wrong.
My first guess was that the r2a11302 pmic is still responding to commands,
corrupting your data, but you do force its CS line high through a GPIO hog.
Have you hooked up a logic analyzer?
Is the GPIO hog for MSIOF1_SYNC_3 working? You can monitor it on EXIO A pin 23.
Is cs-gpios working correctly in the spi-sh-msiof driver? You can monitor it on
EXIO B pin 7.
Is the PMIC driving MSIOF1_RXD_3 anyway? You can check if you unjumper EXIO A
pin 33.
Perhaps the PMIC just does't like seeing a 25 MHz signal on the CLK line? It has
spi-max-frequency = <6000000> in DT.
Running out of ideas for now...
Good luck!
> --- a/arch/arm/boot/dts/r8a7790-lager.dts
> +++ b/arch/arm/boot/dts/r8a7790-lager.dts
> @@ -535,12 +558,24 @@
> status = "okay";
> };
>
> +#if 1
> &msiof1 {
> pinctrl-0 = <&msiof1_pins>;
> pinctrl-names = "default";
>
> status = "okay";
>
> + num-chipselects = <1>;
The spi-sh-msiof driver uses "num-cs" instead.
Shouldn't make a difference here, as the default value in the absence of the
property is 1.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
