[PATCH v4 7/8] gpio: pci-idio-16: Utilize for_each_set_clump macro

From: William Breathitt Gray
Date: Tue May 15 2018 - 13:41:27 EST


Replace verbose implementation in get_multiple/set_multiple callbacks
with for_each_set_clump macro to simplify code and improve clarity.

Signed-off-by: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
---
drivers/gpio/gpio-pci-idio-16.c | 67 +++++++++++----------------------
1 file changed, 21 insertions(+), 46 deletions(-)

diff --git a/drivers/gpio/gpio-pci-idio-16.c b/drivers/gpio/gpio-pci-idio-16.c
index 25d16b2af1c3..6d748c6e59cb 100644
--- a/drivers/gpio/gpio-pci-idio-16.c
+++ b/drivers/gpio/gpio-pci-idio-16.c
@@ -109,44 +109,20 @@ static int idio_16_gpio_get_multiple(struct gpio_chip *chip,
{
struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
size_t i;
- const unsigned int gpio_reg_size = 8;
- unsigned int bits_offset;
- size_t word_index;
- unsigned int word_offset;
- unsigned long word_mask;
- const unsigned long port_mask = GENMASK(gpio_reg_size - 1, 0);
- unsigned long port_state;
+ size_t word;
+ unsigned int offset;
void __iomem *ports[] = {
&idio16gpio->reg->out0_7, &idio16gpio->reg->out8_15,
&idio16gpio->reg->in0_7, &idio16gpio->reg->in8_15,
};
+ unsigned long port_state;

/* clear bits array to a clean slate */
bitmap_zero(bits, chip->ngpio);

- /* get bits are evaluated a gpio port register at a time */
- for (i = 0; i < ARRAY_SIZE(ports); i++) {
- /* gpio offset in bits array */
- bits_offset = i * gpio_reg_size;
-
- /* word index for bits array */
- word_index = BIT_WORD(bits_offset);
-
- /* gpio offset within current word of bits array */
- word_offset = bits_offset % BITS_PER_LONG;
-
- /* mask of get bits for current gpio within current word */
- word_mask = mask[word_index] & (port_mask << word_offset);
- if (!word_mask) {
- /* no get bits in this port so skip to next one */
- continue;
- }
-
- /* read bits from current gpio port */
+ for_each_set_clump(i, word, offset, mask, ARRAY_SIZE(ports), 8) {
port_state = ioread8(ports[i]);
-
- /* store acquired bits at respective bits array offset */
- bits[word_index] |= port_state << word_offset;
+ bits[word] |= port_state << offset;
}

return 0;
@@ -186,30 +162,29 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
unsigned long *mask, unsigned long *bits)
{
struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
+ size_t i;
+ size_t word;
+ unsigned int offset;
+ void __iomem *ports[] = {
+ &idio16gpio->reg->out0_7, &idio16gpio->reg->out8_15,
+ };
+ unsigned int iomask;
+ unsigned int bitmask;
unsigned long flags;
unsigned int out_state;

- raw_spin_lock_irqsave(&idio16gpio->lock, flags);
+ for_each_set_clump(i, word, offset, mask, ARRAY_SIZE(ports), 8) {
+ iomask = mask[word] >> offset;
+ bitmask = iomask & (bits[word] >> offset);

- /* process output lines 0-7 */
- if (*mask & 0xFF) {
- out_state = ioread8(&idio16gpio->reg->out0_7) & ~*mask;
- out_state |= *mask & *bits;
- iowrite8(out_state, &idio16gpio->reg->out0_7);
- }
+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);

- /* shift to next output line word */
- *mask >>= 8;
+ out_state = ioread8(ports[i]) & ~iomask;
+ out_state |= bitmask;
+ iowrite8(out_state, ports[i]);

- /* process output lines 8-15 */
- if (*mask & 0xFF) {
- *bits >>= 8;
- out_state = ioread8(&idio16gpio->reg->out8_15) & ~*mask;
- out_state |= *mask & *bits;
- iowrite8(out_state, &idio16gpio->reg->out8_15);
+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
-
- raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}

static void idio_16_irq_ack(struct irq_data *data)
--
2.17.0