linux-kernel - [PATCH v3 08/10] gpio: exar: Refactor address and bit calculations

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 26 May 2017 18:02:35 +0200
From:   Jan Kiszka <jan.kiszka@...mens.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        Alexandre Courbot <gnurou@...il.com>
Cc:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-serial@...r.kernel.org, linux-gpio@...r.kernel.org,
        Sudip Mukherjee <sudip.mukherjee@...ethink.co.uk>,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        Sascha Weisenberger <sascha.weisenberger@...mens.com>
Subject: [PATCH v3 08/10] gpio: exar: Refactor address and bit calculations

Make the address and bit calculation more friendly for introducing a
"first pin" offset later on. The new form is also more compact and
regular.

Signed-off-by: Jan Kiszka <jan.kiszka@...mens.com>
---
 drivers/gpio/gpio-exar.c | 38 ++++++++++++++++----------------------
 1 file changed, 16 insertions(+), 22 deletions(-)

diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
index 1a629831d45b..d13bf20b8639 100644
--- a/drivers/gpio/gpio-exar.c
+++ b/drivers/gpio/gpio-exar.c
@@ -51,11 +51,11 @@ static void exar_update(struct gpio_chip *chip, unsigned int reg, int val,
 static int exar_set_direction(struct gpio_chip *chip, int direction,
 			      unsigned int offset)
 {
-	unsigned int bank = offset / 8;
-	unsigned int addr;
+	unsigned int addr = offset / 8 ?
+		EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
+	unsigned int bit  = offset % 8;
 
-	addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
-	exar_update(chip, addr, direction, offset % 8);
+	exar_update(chip, addr, direction, bit);
 	return 0;
 }
 
@@ -73,36 +73,30 @@ static int exar_get(struct gpio_chip *chip, unsigned int reg)
 
 static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
 {
-	unsigned int bank = offset / 8;
-	unsigned int addr;
-	int val;
+	unsigned int addr = offset / 8 ?
+		EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
+	unsigned int bit  = offset % 8;
 
-	addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
-	val = exar_get(chip, addr) & BIT(offset % 8);
-
-	return !!val;
+	return !!(exar_get(chip, addr) & BIT(bit));
 }
 
 static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
 {
-	unsigned int bank = offset / 8;
-	unsigned int addr;
-	int val;
-
-	addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
-	val = exar_get(chip, addr) & BIT(offset % 8);
+	unsigned int addr = offset / 8 ?
+		EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
+	unsigned int bit  = offset % 8;
 
-	return !!val;
+	return !!(exar_get(chip, addr) & BIT(bit));
 }
 
 static void exar_set_value(struct gpio_chip *chip, unsigned int offset,
 			   int value)
 {
-	unsigned int bank = offset / 8;
-	unsigned int addr;
+	unsigned int addr = offset / 8 ?
+		EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
+	unsigned int bit  = offset % 8;
 
-	addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
-	exar_update(chip, addr, value, offset % 8);
+	exar_update(chip, addr, value, bit);
 }
 
 static int exar_direction_output(struct gpio_chip *chip, unsigned int offset,
-- 
2.12.0