Re: simple gpio driver
From: Anton Vorontsov <hidden>
Date: 2009-08-17 23:38:37
Oops, I missed that patch, sorry. On Mon, Aug 17, 2009 at 03:18:37PM -0600, Grant Likely wrote:
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.
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. Thanks, -- Anton Vorontsov email: cbouatmailru@gmail.com irc://irc.freenode.net/bd2