Re: simple gpio driver

Hello Anton,

Anton Vorontsov wrote:

Oops, I missed that patch, sorry.

On Mon, Aug 17, 2009 at 03:18:37PM -0600, Grant Likely wrote:

quoted

On Wed, Aug 12, 2009 at 11:49 PM, Heiko Schocher[off-list ref] wrote:

quoted

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,

There is also arch/powerpc/sysdev/qe_lib/gpio.c and
arch/powerpc/sysdev/mpc8xxx_gpio.c that don't do that.

Ah, okay.

quoted

quoted

which seems correct to me, because a gpio can have only 1 or 0
as state ... what do you think?

I think returning '1' is perhaps slightly 'better' (however you define
that), but I don't think the caller should make any assumptions beyond
zero/non-zero.

Yep. So I don't think that the patch is needed.

Yes, if the gpio lib only differs in zero versus non zero.

Thanks for the info

bye
Heiko
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