[patch 36/86] gpio: max3191x: utilize the for_each_set_clump8 macro

Andrew Morton
2019-12-05T00:51:43Z

From: William Breathitt Gray <vilhelm.gray@gmail.com>
Subject: gpio: max3191x: 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/c2b1ed62caf6fce6e5681809a50c05ce6acdf2a6.1570641097.git.vilhelm.gray@gmail.com
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Lukas Wunner <lukas@wunner.de>
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: Masahiro Yamada <yamada.masahiro@socionext.com>
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>
---

drivers/gpio/gpio-max3191x.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

--- a/drivers/gpio/gpio-max3191x.c~gpio-max3191x-utilize-the-for_each_set_clump8-macro
+++ a/drivers/gpio/gpio-max3191x.c
@@ -31,6 +31,7 @@
*/

#include <linux/bitmap.h>
+#include <linux/bitops.h>
#include <linux/crc8.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
@@ -232,16 +233,20 @@ static int max3191x_get_multiple(struct
unsigned long *bits)
{
struct max3191x_chip *max3191x = gpiochip_get_data(gpio);
- int ret, bit = 0, wordlen = max3191x_wordlen(max3191x);
+ const unsigned int wordlen = max3191x_wordlen(max3191x);
+ int ret;
+ unsigned long bit;
+ unsigned long gpio_mask;
+ unsigned long in;

mutex_lock(&max3191x->lock);
ret = max3191x_readout_locked(max3191x);
if (ret)
goto out_unlock;

- while ((bit = find_next_bit(mask, gpio->ngpio, bit)) != gpio->ngpio) {
+ bitmap_zero(bits, gpio->ngpio);
+ for_each_set_clump8(bit, gpio_mask, mask, gpio->ngpio) {
unsigned int chipnum = bit / MAX3191X_NGPIO;
- unsigned long in, shift, index;

if (max3191x_chip_is_faulting(max3191x, chipnum)) {
ret = -EIO;
@@ -249,12 +254,8 @@ static int max3191x_get_multiple(struct
}

in = ((u8 *)max3191x->xfer.rx_buf)[chipnum * wordlen];
- shift = round_down(bit % BITS_PER_LONG, MAX3191X_NGPIO);
- index = bit / BITS_PER_LONG;
- bits[index] &= ~(mask[index] & (0xff << shift));
- bits[index] |= mask[index] & (in << shift); /* copy bits */
-
- bit = (chipnum + 1) * MAX3191X_NGPIO; /* go to next chip */
+ in &= gpio_mask;
+ bitmap_set_value8(bits, in, bit);
}

out_unlock:
_