gpio: ich: Use BIT() macro

Using BIT() makes (1 << foo) constructions easier to read, and
also account for common mistakes where bit 31 is not working
because of numbers being interpreted as negative unless
specified as unsigned.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-ich.c

@@ -26,6 +26,7 @@
 #include <linux/gpio/driver.h>
 #include <linux/platform_device.h>
 #include <linux/mfd/lpc_ich.h>
+#include <linux/bitops.h>
 
 #define DRV_NAME "gpio_ich"
 
@@ -131,9 +132,9 @@ static int ichx_write_bit(int reg, unsigned nr, int val, int verify)
 				 ichx_priv.gpio_base);
 
 	if (val)
-		data |= 1 << bit;
+		data |= BIT(bit);
 	else
-		data &= ~(1 << bit);
+		data &= ~BIT(bit);
 	ICHX_WRITE(data, ichx_priv.desc->regs[reg][reg_nr],
 			 ichx_priv.gpio_base);
 	if (reg == GPIO_LVL && ichx_priv.desc->use_outlvl_cache)
@@ -166,12 +167,12 @@ static int ichx_read_bit(int reg, unsigned nr)
 
 	spin_unlock_irqrestore(&ichx_priv.lock, flags);
 
-	return data & (1 << bit) ? 1 : 0;
+	return !!(data & BIT(bit));
 }
 
 static bool ichx_gpio_check_available(struct gpio_chip *gpio, unsigned nr)
 {
-	return !!(ichx_priv.use_gpio & (1 << (nr / 32)));
+	return !!(ichx_priv.use_gpio & BIT(nr / 32));
 }
 
 static int ichx_gpio_get_direction(struct gpio_chip *gpio, unsigned nr)
@@ -232,12 +233,12 @@ static int ich6_gpio_get(struct gpio_chip *chip, unsigned nr)
 		spin_lock_irqsave(&ichx_priv.lock, flags);
 
 		/* GPI 0 - 15 are latched, write 1 to clear*/
-		ICHX_WRITE(1 << (16 + nr), 0, ichx_priv.pm_base);
+		ICHX_WRITE(BIT(16 + nr), 0, ichx_priv.pm_base);
 		data = ICHX_READ(0, ichx_priv.pm_base);
 
 		spin_unlock_irqrestore(&ichx_priv.lock, flags);
 
-		return (data >> 16) & (1 << nr) ? 1 : 0;
+		return !!((data >> 16) & BIT(nr));
 	} else {
 		return ichx_gpio_get(chip, nr);
 	}
@@ -254,7 +255,7 @@ static int ichx_gpio_request(struct gpio_chip *chip, unsigned nr)
 	 * the chipset's USE value can be trusted for this specific bit.
 	 * If it can't be trusted, assume that the pin can be used as a GPIO.
 	 */
-	if (ichx_priv.desc->use_sel_ignore[nr / 32] & (1 << (nr & 0x1f)))
+	if (ichx_priv.desc->use_sel_ignore[nr / 32] & BIT(nr & 0x1f))
 		return 0;
 
 	return ichx_read_bit(GPIO_USE_SEL, nr) ? 0 : -ENODEV;
@@ -394,7 +395,7 @@ static int ichx_gpio_request_regions(struct device *dev,
 		return -ENODEV;
 
 	for (i = 0; i < ARRAY_SIZE(ichx_priv.desc->regs[0]); i++) {
-		if (!(use_gpio & (1 << i)))
+		if (!(use_gpio & BIT(i)))
 			continue;
 		if (!devm_request_region(dev,
 				res_base->start + ichx_priv.desc->regs[0][i],