On Sat, May 02, 2020 at 03:03:54PM -0400, William Breathitt Gray wrote:
> On Sun, May 03, 2020 at 12:21:54AM +0530, Syed Nayyar Waris wrote:
> > This patch reimplements the xgpio_set_multiple function in
> > drivers/gpio/gpio-xilinx.c to use the new for_each_set_clump macro.
> > Instead of looping for each bit in xgpio_set_multiple
> > function, now we can check each channel at a time and save cycles.
> >
> > Cc: Linus Walleij <linus.wall...@linaro.org>
> > Cc: Bartosz Golaszewski <bgolaszew...@baylibre.com>
> > Cc: Michal Simek <michal.si...@xilinx.com>
> > Signed-off-by: Syed Nayyar Waris <syednwa...@gmail.com>
> > Signed-off-by: William Breathitt Gray <vilhelm.g...@gmail.com>
> > ---
> > Changes in v4:
> > - Minor change: Hardcode value for better code readability.
> >
> > Changes in v3:
> > - No change.
> >
> > Changes in v2:
> > - No change.
> >
> > drivers/gpio/gpio-xilinx.c | 64 ++++++++++++++++++++------------------
> > 1 file changed, 34 insertions(+), 30 deletions(-)
> >
> > diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
> > index 67f9f82e0db0..67c5eeaf1bb9 100644
> > --- a/drivers/gpio/gpio-xilinx.c
> > +++ b/drivers/gpio/gpio-xilinx.c
> > @@ -136,39 +136,43 @@ static void xgpio_set(struct gpio_chip *gc, unsigned
> > int gpio, int val)
> > static void xgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
> > unsigned long *bits)
> > {
> > - unsigned long flags;
> > + unsigned long flags[2];
> > struct xgpio_instance *chip = gpiochip_get_data(gc);
> > - int index = xgpio_index(chip, 0);
> > - int offset, i;
> > -
> > - spin_lock_irqsave(&chip->gpio_lock[index], flags);
> > -
> > - /* Write to GPIO signals */
> > - for (i = 0; i < gc->ngpio; i++) {
> > - if (*mask == 0)
> > - break;
> > - /* Once finished with an index write it out to the register */
> > - if (index != xgpio_index(chip, i)) {
> > - xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
> > - index * XGPIO_CHANNEL_OFFSET,
> > - chip->gpio_state[index]);
> > - spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
> > - index = xgpio_index(chip, i);
> > - spin_lock_irqsave(&chip->gpio_lock[index], flags);
> > - }
> > - if (__test_and_clear_bit(i, mask)) {
> > - offset = xgpio_offset(chip, i);
> > - if (test_bit(i, bits))
> > - chip->gpio_state[index] |= BIT(offset);
> > - else
> > - chip->gpio_state[index] &= ~BIT(offset);
> > - }
> > + u32 *const state = chip->gpio_state;
> > + unsigned int *const width = chip->gpio_width;
> > + const unsigned long state_size = 32;
> > + const unsigned long total_state_bits = state_size * 2;
>
> Hello Syed,
>
> I don't think there's much need for these two variables either. You can
> remove the state_size and total_state_bits variables, and instead inline
> 32 and 64 directly in your code below.
Hi. Have sent v5 patchset incorporating your review comment.
Thank you.
>
> William Breathitt Gray
>
> > + unsigned long offset, clump;
> > + size_t index;
> > +
> > + DECLARE_BITMAP(old, 64);
> > + DECLARE_BITMAP(new, 64);
> > + DECLARE_BITMAP(changed, 64);
> > +
> > + spin_lock_irqsave(&chip->gpio_lock[0], flags[0]);
> > + spin_lock_irqsave(&chip->gpio_lock[1], flags[1]);
> > +
> > + bitmap_set_value(old, state[0], 0, width[0]);
> > + bitmap_set_value(old, state[1], width[0], width[1]);
> > + bitmap_replace(new, old, bits, mask, gc->ngpio);
> > +
> > + bitmap_set_value(old, state[0], 0, state_size);
> > + bitmap_set_value(old, state[1], state_size, state_size);
> > + state[0] = bitmap_get_value(new, 0, width[0]);
> > + state[1] = bitmap_get_value(new, width[0], width[1]);
> > + bitmap_set_value(new, state[0], 0, state_size);
> > + bitmap_set_value(new, state[1], state_size, state_size);
> > + bitmap_xor(changed, old, new, total_state_bits);
> > +
> > + for_each_set_clump(offset, clump, changed, total_state_bits,
> > state_size) {
> > + index = offset / state_size;
> > + xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
> > + index * XGPIO_CHANNEL_OFFSET,
> > + state[index]);
> > }
> >
> > - xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
> > - index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);
> > -
> > - spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
> > + spin_unlock_irqrestore(&chip->gpio_lock[1], flags[1]);
> > + spin_unlock_irqrestore(&chip->gpio_lock[0], flags[0]);
> > }
> >
> > /**
> > --
> > 2.26.2
> >
