gpio: pca953x: utilize the for_each_set_clump8 macro

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

Link: http://lkml.kernel.org/r/3543ffc3668ad4ed4c00e8ebaf14a5559fd6ddf2.1570641097.git.vilhelm.gray@gmail.comSigned-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Phil Reid <preid@electromag.com.au>
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: Morten Hein Tiljeset <morten.tiljeset@prevas.dk>
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-pca953x.c

@@ -10,6 +10,7 @@
 
 #include <linux/acpi.h>
 #include <linux/bits.h>
+#include <linux/bitops.h>
 #include <linux/gpio/driver.h>
 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
@@ -459,7 +460,8 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
 				      unsigned long *mask, unsigned long *bits)
 {
 	struct pca953x_chip *chip = gpiochip_get_data(gc);
-	unsigned int bank_mask, bank_val;
+	unsigned long offset;
+	unsigned long bank_mask;
 	int bank;
 	u8 reg_val[MAX_BANK];
 	int ret;
@@ -469,15 +471,10 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
 	if (ret)
 		goto exit;
 
-	for (bank = 0; bank < NBANK(chip); bank++) {
-		bank_mask = mask[bank / sizeof(*mask)] >>
-			   ((bank % sizeof(*mask)) * 8);
-		if (bank_mask) {
-			bank_val = bits[bank / sizeof(*bits)] >>
-				  ((bank % sizeof(*bits)) * 8);
-			bank_val &= bank_mask;
-			reg_val[bank] = (reg_val[bank] & ~bank_mask) | bank_val;
-		}
+	for_each_set_clump8(offset, bank_mask, mask, gc->ngpio) {
+		bank = offset / 8;
+		reg_val[bank] &= ~bank_mask;
+		reg_val[bank] |= bitmap_get_value8(bits, offset) & bank_mask;
 	}
 
 	pca953x_write_regs(chip, chip->regs->output, reg_val);