Messages in this thread | | | Subject | Re: [BUG] SPI broken for SPI based panel drivers | From | "H. Nikolaus Schaller" <> | Date | Wed, 9 Dec 2020 09:45:04 +0100 |
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Hi Linus,
> Am 09.12.2020 um 09:38 schrieb Linus Walleij <linus.walleij@linaro.org>: > > On Sat, Dec 5, 2020 at 8:07 AM H. Nikolaus Schaller <hns@goldelico.com> wrote: > >> I find it interesting that so far nobody wants to take responsibility >> for a decision > (...) > > >>> What I can do is to provide just a skeleton for the table that you or Linus >>> can fix/fill in and make a patch out of it. Is attached and the ??? is >>> something you should discuss and define. >> >> Please take the attached diff, comment it here and define the question marks >> according to your intention and then make a patch for the YAML bindings out >> of it. (I can't do because I don't know your intentions and what to write into >> the commit message). > > I'll comment what I know, then you can send a proper patch to > Mark. But you really need more people than me to look at this. > >> + device node | cs-gpio | CS pin state active | Note >> + ================+===============+=====================+===== >> + spi-cs-high | - | H | >> + - | - | L | >> + spi-cs-high | ACTIVE_HIGH | H | >> + - | ACTIVE_HIGH | L (or H ???) | 1 > > When using GPIO descriptors it will be enforced to ACTIVE_LOW (L) with an > explicit warning in dmesg, see drivers/gpio/gpiolib-of.c
Ok, so in this line the L is ok.
> > When using legacy GPIOs, will be enforced ACTIVE_LOW by the SPI > core. > >> + spi-cs-high | ACTIVE_LOW | H (or L ???) | 2 > > When using GPIO descriptors it will be enforced to ACTIVE_HIGH (H) with an > explicit warning in dmesg, see drivers/gpio/gpiolib-of.c
Ok, so my assumption about H is right and not the part in parenthesis with ???.
> >> + 3) Effectively this rule defines that the ACTIVE level of the >> + gpio has to be ignored > > Nr 3 isn't tagged in the table.
Well, it was thought as a third but general note. Maybe should have been a *) or omitted since the table stands for itself.
> > Yours, > Linus Walleij
So let me prepare a patch with fixes for this.
BR and thanks, Nikolaus
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