gpio: 74x164: 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/7ea2df7182a50a1136ca36edc46dffcb2446fd27.1570641097.git.vilhelm.gray@gmail.com
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
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: 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>

diff --git a/drivers/gpio/gpio-74x164.c b/drivers/gpio/gpio-74x164.c
index e81307f..05637d5 100644 (file)
--- a/drivers/gpio/gpio-74x164.c
+++ b/drivers/gpio/gpio-74x164.c
@@ -6,6 +6,7 @@
  *  Copyright (C) 2010 Miguel Gaio <miguel.gaio@efixo.com>
  */
 
+#include <linux/bitops.h>
 #include <linux/gpio/consumer.h>
 #include <linux/gpio/driver.h>
 #include <linux/module.h>
@@ -72,20 +73,18 @@ static void gen_74x164_set_multiple(struct gpio_chip *gc, unsigned long *mask,
                                    unsigned long *bits)
 {
        struct gen_74x164_chip *chip = gpiochip_get_data(gc);
-       unsigned int i, idx, shift;
-       u8 bank, bankmask;
+       unsigned long offset;
+       unsigned long bankmask;
+       size_t bank;
+       unsigned long bitmask;
 
        mutex_lock(&chip->lock);
-       for (i = 0, bank = chip->registers - 1; i < chip->registers;
-            i++, bank--) {
-               idx = i / sizeof(*mask);
-               shift = i % sizeof(*mask) * BITS_PER_BYTE;
-               bankmask = mask[idx] >> shift;
-               if (!bankmask)
-                       continue;
+       for_each_set_clump8(offset, bankmask, mask, chip->registers * 8) {
+               bank = chip->registers - 1 - offset / 8;
+               bitmask = bitmap_get_value8(bits, offset) & bankmask;
 
                chip->buffer[bank] &= ~bankmask;
-               chip->buffer[bank] |= bankmask & (bits[idx] >> shift);
+               chip->buffer[bank] |= bitmask;
        }
        __gen_74x164_write_config(chip);
        mutex_unlock(&chip->lock);