Re: [PATCH] pinctrl: msm: allow the gpio base to be configurable

[Timur Tabi <timur@codeaurora.org>]

On 1/26/18 7:01 AM, Linus Walleij wrote:
> This is a feature not a bug. It encourages people not to
> depend on the global GPIO numberspace.
> 
> Just set it to -1.

If I change it to -1, then I think I'm going to break every existing MSM 
platform that depends on the base address being 0, because then every 
MSM driver will have a non-zero base, and none of the existing drivers 
register more than one GPIO device.

So how about this:

	static int base = 0;

	chip->base = base;
	base = -1;

This way, existing code works as before.  If any driver registers two 
GPIO devices, the first one will get a base of 0, and the second one 
will get some other base.

>> gpiochip_find_base: found new base at 437
> (...)
>> gpiochip_find_base: found new base at 362
> These are awesome bases, just beautiful. Use this.
> 
> If you don't like seeing GPIO base numbers like this: use things
> like the chardev and the tools in tools/gpio or libgpiod when
> developing, and you will never see them. They should not make
> a difference anyway.

Can you tell me more about the chardev?  I've always been using "echo X 
 > /sys/class/gpio/export", so I guess that's not the right way to do 
things.

-- 
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc.  Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.