linux-kernel - [PATCH v18 04/14] gpio: 104-idi-48: Utilize for_each_set

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Message-Id: <b0631b6d489f85008480399df283ccd33ecfe310.1570641097.git.vilhelm.gray@gmail.com>
Date:   Wed,  9 Oct 2019 13:14:40 -0400
From:   William Breathitt Gray <vilhelm.gray@...il.com>
To:     linus.walleij@...aro.org, bgolaszewski@...libre.com,
        akpm@...ux-foundation.org
Cc:     linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arch@...r.kernel.org, andriy.shevchenko@...ux.intel.com,
        linux@...musvillemoes.dk, yamada.masahiro@...ionext.com,
        linux-arm-kernel@...ts.infradead.org, linux-pm@...r.kernel.org,
        geert@...ux-m68k.org, preid@...ctromag.com.au, lukas@...ner.de,
        William Breathitt Gray <vilhelm.gray@...il.com>
Subject: [PATCH v18 04/14] gpio: 104-idi-48: Utilize for_each_set_clump8 macro

Replace verbose implementation in get_multiple/set_multiple callbacks
with for_each_set_clump8 macro to simplify code and improve clarity.

Reviewed-by: Linus Walleij <linus.walleij@...aro.org>
Signed-off-by: William Breathitt Gray <vilhelm.gray@...il.com>
---
 drivers/gpio/gpio-104-idi-48.c | 36 +++++++---------------------------
 1 file changed, 7 insertions(+), 29 deletions(-)

diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c
index ff53887bdaa8..bf67040cbbbb 100644
--- a/drivers/gpio/gpio-104-idi-48.c
+++ b/drivers/gpio/gpio-104-idi-48.c
@@ -85,42 +85,20 @@ static int idi_48_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
 	unsigned long *bits)
 {
 	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
-	size_t i;
+	unsigned long offset;
+	unsigned long gpio_mask;
 	static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
-	const unsigned int gpio_reg_size = 8;
-	unsigned int bits_offset;
-	size_t word_index;
-	unsigned int word_offset;
-	unsigned long word_mask;
-	const unsigned long port_mask = GENMASK(gpio_reg_size - 1, 0);
+	unsigned int port_addr;
 	unsigned long port_state;
 
 	/* clear bits array to a clean slate */
 	bitmap_zero(bits, chip->ngpio);
 
-	/* get bits are evaluated a gpio port register at a time */
-	for (i = 0; i < ARRAY_SIZE(ports); i++) {
-		/* gpio offset in bits array */
-		bits_offset = i * gpio_reg_size;
+	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
+		port_addr = idi48gpio->base + ports[offset / 8];
+		port_state = inb(port_addr) & gpio_mask;
 
-		/* word index for bits array */
-		word_index = BIT_WORD(bits_offset);
-
-		/* gpio offset within current word of bits array */
-		word_offset = bits_offset % BITS_PER_LONG;
-
-		/* mask of get bits for current gpio within current word */
-		word_mask = mask[word_index] & (port_mask << word_offset);
-		if (!word_mask) {
-			/* no get bits in this port so skip to next one */
-			continue;
-		}
-
-		/* read bits from current gpio port */
-		port_state = inb(idi48gpio->base + ports[i]);
-
-		/* store acquired bits at respective bits array offset */
-		bits[word_index] |= (port_state << word_offset) & word_mask;
+		bitmap_set_value8(bits, port_state, offset);
 	}
 
 	return 0;
-- 
2.23.0