Re: [PATCH v3 04/14] GPIO: Add gpio-ingenic driver

Linus Walleij
2017-02-03T13:58:50Z

On Tue, Jan 31, 2017 at 4:29 PM, Paul Cercueil <paul@crapouillou.net> wrote:
> Le 2017-01-31 15:20, Linus Walleij a Ã©crit :
>
>>> + of_property_read_u32(dev->of_node, "base", &jzgc->gc.base);
>>
>>
>> Remove this. Dynamic allocation should be fine, if you're using the
>> new userspace ABI like tools/gpio/* or libgpiod and only that and
>> in-kernel
>> consumers, dynamic numbers are just fine.
>
>
> The problem is that the QI_LB60 board code still have a lot of references
> to global GPIO numbers. Just grep for JZ_GPIO_PORT in
> arch/mips/jz4740/board-qi_lb60.c to see what I mean...

OK I understand we might need a compromise here to get the code moving.

But we need to keep it out of the device tree.

I think it's better to put a base table relative to the memory base in
the driver in that case:

unsigned int gpio_global_base;

switch (memory_base_address) {
case 0x41000000:
gpio_global_base = 0x00;
break;
case 0x42000000:
gpio_global_base = 0x20;

(...)

etc. (Those are not your base addresses but you get the idea).

Include a few comments like:

/*
* DO NOT EXPAND THIS: FOR BACKWARD GPIO NUMBERSPACE
* COMPATIBIBILITY ONLY: WORK TO TRANSITION CONSUMERS TO
* USE THE GPIO DESCRIPTOR API IN <linux/gpio/consumer.h> INSTEAD.
*/

Then I'll be happy :)

Yours,
Linus Walleij