gpio: pca953x: Clean up pcal6534_check_register()

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@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 2c8586b..8aba8df 100644 (file)
--- 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;