gpio: gpio-mm: utilize for_each_set_clump8 macro

Replace verbose implementation in get_multiple/set_multiple callbacks
with for_each_set_clump8 macro to simplify code and improve clarity.

Link: http://lkml.kernel.org/r/0de53d7021b2d6db10294473cd8a1b6102bcec94.1570641097.git.vilhelm.gray@gmail.com
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Morten Hein Tiljeset <morten.tiljeset@prevas.dk>
Cc: Phil Reid <preid@electromag.com.au>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpio/gpio-gpio-mm.c

@@ -167,46 +167,25 @@ static int gpiomm_gpio_get(struct gpio_chip *chip, unsigned int offset)
 	return !!(port_state & mask);
 }
 
+static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
+
 static int gpiomm_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
 	unsigned long *bits)
 {
 	struct gpiomm_gpio *const gpiommgpio = 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);
+	unsigned long offset;
+	unsigned long gpio_mask;
+	unsigned int port_addr;
 	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;
+	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
+		port_addr = gpiommgpio->base + ports[offset / 8];
+		port_state = inb(port_addr) & gpio_mask;
 
-		/* 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 */
-		port_state = inb(gpiommgpio->base + ports[i]);
-
-		/* store acquired bits at respective bits array offset */
-		bits[word_index] |= (port_state << word_offset) & word_mask;
+		bitmap_set_value8(bits, port_state, offset);
 	}
 
 	return 0;
@@ -237,37 +216,27 @@ static void gpiomm_gpio_set_multiple(struct gpio_chip *chip,
 	unsigned long *mask, unsigned long *bits)
 {
 	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
-	unsigned int i;
-	const unsigned int gpio_reg_size = 8;
-	unsigned int port;
-	unsigned int out_port;
-	unsigned int bitmask;
+	unsigned long offset;
+	unsigned long gpio_mask;
+	size_t index;
+	unsigned int port_addr;
+	unsigned long 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;
-		}
+	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
+		index = offset / 8;
+		port_addr = gpiommgpio->base + ports[index];
 
-		port = i / gpio_reg_size;
-		out_port = (port > 2) ? port + 1 : port;
-		bitmask = mask[BIT_WORD(i)] & bits[BIT_WORD(i)];
+		bitmask = bitmap_get_value8(bits, offset) & gpio_mask;
 
 		spin_lock_irqsave(&gpiommgpio->lock, flags);
 
 		/* update output state data and set device gpio register */
-		gpiommgpio->out_state[port] &= ~mask[BIT_WORD(i)];
-		gpiommgpio->out_state[port] |= bitmask;
-		outb(gpiommgpio->out_state[port], gpiommgpio->base + out_port);
+		gpiommgpio->out_state[index] &= ~gpio_mask;
+		gpiommgpio->out_state[index] |= bitmask;
+		outb(gpiommgpio->out_state[index], port_addr);
 
 		spin_unlock_irqrestore(&gpiommgpio->lock, flags);
-
-		/* prepare for next gpio register set */
-		mask[BIT_WORD(i)] >>= gpio_reg_size;
-		bits[BIT_WORD(i)] >>= gpio_reg_size;
 	}
 }