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.com
Signed-off-by: William Breathitt Gray <[email protected]>
Tested-by: Andy Shevchenko <[email protected]>
Cc: Phil Reid <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Bartosz Golaszewski <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Linus Walleij <[email protected]>
Cc: Lukas Wunner <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Mathias Duckeck <[email protected]>
Cc: Morten Hein Tiljeset <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Sean Nyekjaer <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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);