Re: [PATCH v2] gpio: gpio-pca953x, Add get_multiple function
From: Paul Thomas
Date: Thu Apr 16 2020 - 11:34:23 EST
On Thu, Apr 16, 2020 at 9:21 AM Bartosz Golaszewski
<bgolaszewski@xxxxxxxxxxxx> wrote:
>
> czw., 16 kwi 2020 o 13:22 Linus Walleij <linus.walleij@xxxxxxxxxx> napisaÅ(a):
> >
> > On Tue, Apr 14, 2020 at 5:30 PM Paul Thomas <pthomas8589@xxxxxxxxx> wrote:
> >
> > > Implement a get_multiple function for gpio-pca953x. If a driver
> > > leaves get_multiple unimplemented then gpio_chip_get_multiple()
> > > in gpiolib.c takes care of it by calling chip->get() as needed.
> > > For i2c chips this is very inefficient. For example if you do an
> > > 8-bit read then instead of a single i2c transaction there are
> > > 8 transactions reading the same byte!
> > >
> > > This has been tested with max7312 chips on a 5.2 kernel.
> > >
> > > Signed-off-by: Paul Thomas <pthomas8589@xxxxxxxxx>
> > > ---
> > > changes from v1: rebased to 5.7-rc1
> >
> > Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> >
> > Since I know Bartosz is queueing other patches for this driver I
> > let him pick it up.
> >
> > Yours,
> > Linus Walleij
>
> Patch applied. I removed the last line of the commit message since I
> guess you did test it on v5.7-rc1 after all?
I applied the patch and compiled the kernel, but I didn't test on our
embedded board with the actual max7312 chips, that board has a whole
series of special commits.
-Paul
>
> Bart