simple gpio driver
Heiko Schocher
hs at denx.de
Thu Aug 13 15:49:42 EST 2009
Hello Anton,
i am trying to use the arch/powerpc/sysdev/simple_gpio.c driver,
for accessing some gpios, and found, that u8_gpio_get()
returns not only a 1 or a 0, instead it returns the real bit
position from the gpio:
gpio return
base value
0 0/0x01
1 0/0x02
2 0/0x04
3 0/0x08
4 0/0x10
5 0/0x20
6 0/0x40
7 0/0x80
I also use the arch/powerpc/platforms/52xx/mpc52xx_gpio.c and
mpc52xx_gpt.c drivers, they all return for a gpio just a 1 or 0,
which seems correct to me, because a gpio can have only 1 or 0
as state ... what do you think?
I solved this issue (if it is) with the following patch:
diff --git a/arch/powerpc/sysdev/simple_gpio.c b/arch/powerpc/sysdev/simple_gpio.c
index 43c4569..bb0d79c 100644
--- a/arch/powerpc/sysdev/simple_gpio.c
+++ b/arch/powerpc/sysdev/simple_gpio.c
@@ -46,7 +46,7 @@ static int u8_gpio_get(struct gpio_chip *gc, unsigned int gpio)
{
struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
- return in_8(mm_gc->regs) & u8_pin2mask(gpio);
+ return (in_8(mm_gc->regs) & u8_pin2mask(gpio) ? 1 : 0);
}
static void u8_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
bye
Heiko
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