[PATCH v2 3/4] gpio: pca953x: Clean up pcal6534_check_register()

From: Andy Shevchenko
Date: Sat Dec 10 2022 - 17:05:58 EST


The pcal6534_check_register() is a bit too verbose.
Clean up it, by deduplicating some operations and
switching to the modulo operation as on some architectures
/ and % can become a single assembly instruction.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
v2: new patch
drivers/gpio/gpio-pca953x.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 2c8586b3191f..8aba8df393bd 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -306,6 +306,7 @@ static bool pca953x_check_register(struct pca953x_chip *chip, unsigned int reg,
static bool pcal6534_check_register(struct pca953x_chip *chip, unsigned int reg,
u32 checkbank)
{
+ int bank_shift;
int bank;
int offset;

@@ -314,26 +315,22 @@ static bool pcal6534_check_register(struct pca953x_chip *chip, unsigned int reg,
* Handle lack of reserved registers after output port
* configuration register to form a bank.
*/
- int temp = reg - 0x54;
-
- bank = temp / NBANK(chip);
- offset = temp - (bank * NBANK(chip));
- bank += 16;
+ reg -= 0x54;
+ bank_shift = 16;
} else if (reg >= 0x30) {
/*
* Reserved block between 14h and 2Fh does not align on
* expected bank boundaries like other devices.
*/
- int temp = reg - 0x30;
-
- bank = temp / NBANK(chip);
- offset = temp - (bank * NBANK(chip));
- bank += 8;
+ reg -= 0x30;
+ bank_shift = 8;
} else {
- bank = reg / NBANK(chip);
- offset = reg - (bank * NBANK(chip));
+ bank_shift = 0;
}

+ bank = bank_shift + reg / NBANK(chip);
+ offset = reg % NBANK(chip);
+
/* Register is not in the matching bank. */
if (!(BIT(bank) & checkbank))
return false;
--
2.35.1