Re: [PATCH 01/12] gpio: mmio: use new GPIO line value setter callbacks

[Bartosz Golaszewski <brgl@bgdev.pl>]

On Wed, Jun 18, 2025 at 1:59 PM Klara Modin <klarasmodin@gmail.com> wrote:
>
> Hi,
>
> On 2025-06-10 14:33:11 +0200, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> >
> > struct gpio_chip now has callbacks for setting line values that return
> > an integer, allowing to indicate failures. Convert the driver to using
> > them.
> >
> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> > ---
> >  drivers/gpio/gpio-mmio.c | 53 ++++++++++++++++++++++++++++++------------------
> >  1 file changed, 33 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/gpio/gpio-mmio.c b/drivers/gpio/gpio-mmio.c
> > index 4841e4ebe7a67d0f954e9a6f995ec5758f124edd..9169eccadb238efe944d494054b1e009f16eee7f 100644
> > --- a/drivers/gpio/gpio-mmio.c
> > +++ b/drivers/gpio/gpio-mmio.c
> > @@ -211,11 +211,12 @@ static int bgpio_get_multiple_be(struct gpio_chip *gc, unsigned long *mask,
> >       return 0;
> >  }
> >
> > -static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)
> > +static int bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)
> >  {
> > +     return 0;
> >  }
> >
> > -static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
> > +static int bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
> >  {
> >       unsigned long mask = bgpio_line2mask(gc, gpio);
> >       unsigned long flags;
> > @@ -230,10 +231,12 @@ static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
> >       gc->write_reg(gc->reg_dat, gc->bgpio_data);
> >
> >       raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
> > +
> > +     return 0;
> >  }
> >
> > -static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
> > -                              int val)
> > +static int bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
> > +                             int val)
> >  {
> >       unsigned long mask = bgpio_line2mask(gc, gpio);
> >
> > @@ -241,9 +244,11 @@ static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
> >               gc->write_reg(gc->reg_set, mask);
> >       else
> >               gc->write_reg(gc->reg_clr, mask);
> > +
> > +     return 0;
> >  }
> >
> > -static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)
> > +static int bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)
> >  {
> >       unsigned long mask = bgpio_line2mask(gc, gpio);
> >       unsigned long flags;
> > @@ -258,6 +263,8 @@ static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)
> >       gc->write_reg(gc->reg_set, gc->bgpio_data);
> >
> >       raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
> > +
> > +     return 0;
> >  }
> >
> >  static void bgpio_multiple_get_masks(struct gpio_chip *gc,
> > @@ -298,21 +305,25 @@ static void bgpio_set_multiple_single_reg(struct gpio_chip *gc,
> >       raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
> >  }
> >
> > -static void bgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
> > +static int bgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
> >                              unsigned long *bits)
> >  {
> >       bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_dat);
> > +
> > +     return 0;
> >  }
> >
> > -static void bgpio_set_multiple_set(struct gpio_chip *gc, unsigned long *mask,
> > -                                unsigned long *bits)
> > +static int bgpio_set_multiple_set(struct gpio_chip *gc, unsigned long *mask,
> > +                               unsigned long *bits)
> >  {
> >       bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_set);
> > +
> > +     return 0;
> >  }
> >
> > -static void bgpio_set_multiple_with_clear(struct gpio_chip *gc,
> > -                                       unsigned long *mask,
> > -                                       unsigned long *bits)
> > +static int bgpio_set_multiple_with_clear(struct gpio_chip *gc,
> > +                                      unsigned long *mask,
> > +                                      unsigned long *bits)
> >  {
> >       unsigned long set_mask, clear_mask;
> >
> > @@ -322,6 +333,8 @@ static void bgpio_set_multiple_with_clear(struct gpio_chip *gc,
> >               gc->write_reg(gc->reg_set, set_mask);
> >       if (clear_mask)
> >               gc->write_reg(gc->reg_clr, clear_mask);
> > +
> > +     return 0;
> >  }
> >
> >  static int bgpio_dir_return(struct gpio_chip *gc, unsigned int gpio, bool dir_out)
> > @@ -510,18 +523,18 @@ static int bgpio_setup_io(struct gpio_chip *gc,
> >       if (set && clr) {
> >               gc->reg_set = set;
> >               gc->reg_clr = clr;
> > -             gc->set = bgpio_set_with_clear;
> > -             gc->set_multiple = bgpio_set_multiple_with_clear;
> > +             gc->set_rv = bgpio_set_with_clear;
> > +             gc->set_multiple_rv = bgpio_set_multiple_with_clear;
> >       } else if (set && !clr) {
> >               gc->reg_set = set;
> > -             gc->set = bgpio_set_set;
> > -             gc->set_multiple = bgpio_set_multiple_set;
> > +             gc->set_rv = bgpio_set_set;
> > +             gc->set_multiple_rv = bgpio_set_multiple_set;
> >       } else if (flags & BGPIOF_NO_OUTPUT) {
> > -             gc->set = bgpio_set_none;
> > -             gc->set_multiple = NULL;
> > +             gc->set_rv = bgpio_set_none;
> > +             gc->set_multiple_rv = NULL;
> >       } else {
> > -             gc->set = bgpio_set;
> > -             gc->set_multiple = bgpio_set_multiple;
> > +             gc->set_rv = bgpio_set;
> > +             gc->set_multiple_rv = bgpio_set_multiple;
> >       }
> >
> >       if (!(flags & BGPIOF_UNREADABLE_REG_SET) &&
> > @@ -654,7 +667,7 @@ int bgpio_init(struct gpio_chip *gc, struct device *dev,
> >       }
> >
> >       gc->bgpio_data = gc->read_reg(gc->reg_dat);
> > -     if (gc->set == bgpio_set_set &&
> > +     if (gc->set_rv == bgpio_set_set &&
> >                       !(flags & BGPIOF_UNREADABLE_REG_SET))
> >               gc->bgpio_data = gc->read_reg(gc->reg_set);
> >
> >
> > --
> > 2.48.1
> >
>
> Isn't this missing to convert gc->set() to gc-set_rv() in several
> places?
>
> Without the attached diff I get a null pointer reference on e.g. the
> spacemit k1 driver.
>

Ah, yes, sorry for this and thanks for the catch. I will send a follow-up.

Bartosz