gpio: pisosr: utilize the for_each_set_clump8 macro

Replace verbose implementation in get_multiple callback with
for_each_set_clump8 macro to simplify code and improve clarity.

Link: http://lkml.kernel.org/r/8a39ee772247d4b7d752b32dbacc06c1cdcb60b5.1570641097.git.vilhelm.gray@gmail.com
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Morten Hein Tiljeset <morten.tiljeset@prevas.dk>
Cc: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
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: Linus Walleij <linus.walleij@linaro.org>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Phil Reid <preid@electromag.com.au>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpio/gpio-pisosr.c

@@ -96,16 +96,16 @@ static int pisosr_gpio_get_multiple(struct gpio_chip *chip,
 				    unsigned long *mask, unsigned long *bits)
 {
 	struct pisosr_gpio *gpio = gpiochip_get_data(chip);
-	unsigned int nbytes = DIV_ROUND_UP(chip->ngpio, 8);
-	unsigned int i, j;
+	unsigned long offset;
+	unsigned long gpio_mask;
+	unsigned long buffer_state;
 
 	pisosr_gpio_refresh(gpio);
 
 	bitmap_zero(bits, chip->ngpio);
-	for (i = 0; i < nbytes; i++) {
-		j = i / sizeof(unsigned long);
-		bits[j] |= ((unsigned long) gpio->buffer[i])
-			   << (8 * (i % sizeof(unsigned long)));
+	for_each_set_clump8(offset, gpio_mask, mask, chip->ngpio) {
+		buffer_state = gpio->buffer[offset / 8] & gpio_mask;
+		bitmap_set_value8(bits, buffer_state, offset);
 	}
 
 	return 0;