Messages in this thread Patch in this message | | | From | Linus Walleij <> | Date | Thu, 12 Dec 2019 14:40:29 +0100 | Subject | Re: [PATCH v3 3/7] gpiolib: Add support for GPIO line table lookup |
| |
On Wed, Nov 27, 2019 at 9:43 AM Geert Uytterhoeven <geert+renesas@glider.be> wrote:
> Currently GPIOs can only be referred to by GPIO controller and offset in > GPIO lookup tables. > > Add support for looking them up by line name. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
OK I see what you want to do...
> + if (p->chip_hwnum == (u16)-1) {
If you want to use this then use:
if (p->chip_hwnum == U16_MAX)
from <linux/limits.h>
> + desc = gpio_name_to_desc(p->chip_label); > + if (desc) { > + *flags = p->flags; > + return desc; > + } > + > + dev_warn(dev, "cannot find GPIO line %s, deferring\n", > + p->chip_label); > + return ERR_PTR(-EPROBE_DEFER); > + } > + > chip = find_chip_by_name(p->chip_label); > > if (!chip) { > diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h > index 1ebe5be05d5f81fa..84c1c097e55eefaf 100644 > --- a/include/linux/gpio/machine.h > +++ b/include/linux/gpio/machine.h > @@ -31,7 +31,7 @@ enum gpio_lookup_flags { > */ > struct gpiod_lookup { > const char *chip_label; > - u16 chip_hwnum; > + u16 chip_hwnum; /* if -1, chip_label is named line */
/* if U16_MAX then chip_label is the named line we are looking for */
But the member name "chip_label" is completely abused with this setup, it should then be renamed as part of the patch set to something like chip_label_or_line_name so it is clear what it is or just name it "const char *key".
But I'm not entirely convinced about reusing the existing struct gpio_lookup for this.
What about constructing a new lookup struct specifically for this? I understand it is more work, but will that not be more maintainable and readable?
Yours, Linus Walleij
| |