[PATCH v7 4/4] gpio: xilinx: Utilize for_each_set_clump macro

Syed Nayyar Waris
2020-05-24T05:07:15Z

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: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
Changes in v7:
- No change.

Changes in v6:
- No change.

Changes in v5:
- Minor change: Inline values '32' and '64' in code for better
code readability.

Changes in v4:
- Minor change: Inline values '32' and '64' in code for better
code readability.

Changes in v3:
- No change.

Changes in v2:
- No change.

drivers/gpio/gpio-xilinx.c | 62 ++++++++++++++++++++------------------
1 file changed, 32 insertions(+), 30 deletions(-)

diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index 67f9f82e0db0..e81092dea27e 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -136,39 +136,41 @@ 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;
+ 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, 32);
+ bitmap_set_value(old, state[1], 32, 32);
+ 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, 32);
+ bitmap_set_value(new, state[1], 32, 32);
+ bitmap_xor(changed, old, new, 64);
+
+ for_each_set_clump(offset, clump, changed, 64, 32) {
+ index = offset / 32;
+ 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