ARM: pxa: fix GPIO double shifts

The commit 9bf448c66d4b ("ARM: pxa: use generic gpio operation instead of
gpio register") from Oct 17, 2011, leads to the following static checker
warning:
  arch/arm/mach-pxa/spitz_pm.c:172 spitz_charger_wakeup()
  warn: double left shift '!gpio_get_value(SPITZ_GPIO_KEY_INT)
        << (1 << ((SPITZ_GPIO_KEY_INT) & 31))'

As Dan reported, the value is shifted three times :
 - once by gpio_get_value(), which returns either 0 or BIT(gpio)
 - once by the shift operation '<<'
 - a last time by GPIO_bit(gpio) which is BIT(gpio)

Therefore the calculation lead to a chained or operator of :
 - (1 << gpio) << (1 << gpio) = (2^gpio)^gpio = 2 ^ (gpio * gpio)

It is be sheer luck the former statement works, only because each gpio
used is strictly smaller than 6, and therefore 2^(gpio^2) never
overflows a 32 bits value, and because it is used as a boolean value to
check a gpio activation.

As the xxx_charger_wakeup() functions are used as a true/false detection
mechanism, take that opportunity to change their prototypes from integer
return value to boolean one.

Fixes: 9bf448c66d4b ("ARM: pxa: use generic gpio operation instead of
gpio register")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/arm/mach-pxa/sharpsl_pm.c b/arch/arm/mach-pxa/sharpsl_pm.c
index b80eab9993c5..249b7bd5fbc4 100644
--- a/arch/arm/mach-pxa/sharpsl_pm.c
+++ b/arch/arm/mach-pxa/sharpsl_pm.c
@@ -744,7 +744,7 @@ static int sharpsl_off_charge_battery(void)
 		time = RCNR;
 		while (1) {
 			/* Check if any wakeup event had occurred */
-			if (sharpsl_pm.machinfo->charger_wakeup() != 0)
+			if (sharpsl_pm.machinfo->charger_wakeup())
 				return 0;
 			/* Check for timeout */
 			if ((RCNR - time) > SHARPSL_WAIT_CO_TIME)