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.
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
>
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