[PATCH v3 3/8] gpio: 104-dio-48e: Utilize for_each_set_clump macro

From: William Breathitt Gray
Date: Tue May 15 2018 - 13:40:40 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-104-dio-48e.c | 67 ++++++++-------------------------
1 file changed, 16 insertions(+), 51 deletions(-)

diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c
index 9c4e07fcb74b..77eeaa36094c 100644
--- a/drivers/gpio/gpio-104-dio-48e.c
+++ b/drivers/gpio/gpio-104-dio-48e.c
@@ -183,46 +183,23 @@ static int dio48e_gpio_get(struct gpio_chip *chip, unsigned offset)
return !!(port_state & mask);
}

+static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
+
static int dio48e_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
unsigned long *bits)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
size_t i;
- static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
- 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);
+ size_t word;
+ unsigned int offset;
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 = inb(dio48egpio->base + ports[i]);
-
- /* store acquired bits at respective bits array offset */
- bits[word_index] |= port_state << word_offset;
+ bits[word] |= port_state << offset;
}

return 0;
@@ -252,37 +229,25 @@ static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
unsigned long *mask, unsigned long *bits)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
- unsigned int i;
- const unsigned int gpio_reg_size = 8;
- unsigned int port;
- unsigned int out_port;
+ size_t i;
+ size_t word;
+ unsigned int offset;
+ unsigned int iomask;
unsigned int bitmask;
unsigned long flags;

- /* set bits are evaluated a gpio register size at a time */
- for (i = 0; i < chip->ngpio; i += gpio_reg_size) {
- /* no more set bits in this mask word; skip to the next word */
- if (!mask[BIT_WORD(i)]) {
- i = (BIT_WORD(i) + 1) * BITS_PER_LONG - gpio_reg_size;
- continue;
- }
-
- port = i / gpio_reg_size;
- out_port = (port > 2) ? port + 1 : port;
- bitmask = mask[BIT_WORD(i)] & bits[BIT_WORD(i)];
+ for_each_set_clump(i, word, offset, mask, ARRAY_SIZE(ports), 8) {
+ iomask = mask[word] >> offset;
+ bitmask = iomask & (bits[word] >> offset);

raw_spin_lock_irqsave(&dio48egpio->lock, flags);

/* update output state data and set device gpio register */
- dio48egpio->out_state[port] &= ~mask[BIT_WORD(i)];
- dio48egpio->out_state[port] |= bitmask;
- outb(dio48egpio->out_state[port], dio48egpio->base + out_port);
+ dio48egpio->out_state[i] &= ~iomask;
+ dio48egpio->out_state[i] |= bitmask;
+ outb(dio48egpio->out_state[i], dio48egpio->base + ports[i]);

raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
-
- /* prepare for next gpio register set */
- mask[BIT_WORD(i)] >>= gpio_reg_size;
- bits[BIT_WORD(i)] >>= gpio_reg_size;
}
}

--
2.17.0