Re: [PATCH v2 2/2] gpio: Add support for Intel Cherryview/Braswell GPIO controller

From: Mika Westerberg
Date: Wed Sep 24 2014 - 05:31:51 EST


On Wed, Sep 24, 2014 at 11:10:39AM +0200, Linus Walleij wrote:
> On Mon, Sep 15, 2014 at 4:09 PM, Mika Westerberg
> <mika.westerberg@xxxxxxxxxxxxxxx> wrote:
>
> > From: Ning Li <ning.li@xxxxxxxxx>
> >
> > This driver supports the GPIO controllers found in newer Intel SoCs like
> > Cherryview and Braswell.
> >
> > Signed-off-by: Ning Li <ning.li@xxxxxxxxx>
> > Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
> > Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> (...)
> > +#define FAMILY0_PAD_REGS_OFF 0x4400
> > +#define FAMILY_PAD_REGS_SIZE 0x400
> > +#define MAX_FAMILY_PAD_GPIO_NO 15
>
> Pad registers...
>
> > +static const char * const north_pads[] = {
> > + "GPIO_DFX_0",
> > + "GPIO_DFX_3",
> > + "GPIO_DFX_7",
> > + "GPIO_DFX_1",
> > + "GPIO_DFX_5",
> > + "GPIO_DFX_4",
> > + "GPIO_DFX_8",
> > + "GPIO_DFX_2",
> > + "GPIO_DFX_6",
>
> And then even naming them and stuff.
>
> This is almost a schoolbook definition of stuff that pertains
> to the pin control subsystem rather than GPIO, and this
> info in particular shall be encoded in the .pins field of
> the struct pinctrl_desc. Which is where we name pins.
>
> > + switch ((ctrl0 & CV_GPIO_CFG_MASK) >> 8) {
> > + case 0:
> > + dir = "in out";
> > + break;
> > + case 1:
> > + dir = " out";
> > + break;
> > + case 2:
> > + dir = "in";
> > + break;
> > + case 3:
> > + dir = "HiZ";
> > + break;
>
> And here there is even pin config like HiZ, which is in the kernel
> called PIN_CONFIG_BIAS_HIGH_IMPEDANCE with generic
> pin config.
>
> In short it seems the driver is written by someone who has never
> heard of pin control or doesn't realize that this is exactly what
> pin control is about.

Heh, I actually looked into pinctrl but somehow couldn't find any fit
there.

> Read Documentation/pinctrl.txt and rewrite the entire driver to
> use pin control, and generic pin config like everyone else.

Will do, thanks.
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