Re: [PATCH 1/2] GPIO: Add support for dual channel in gpio-xilinx.c

[Linus Walleij <linus.walleij@linaro.org>]

On Thu, Jun 20, 2013 at 9:51 AM, Michal Simek <monstr@monstr.eu> wrote:
> On 06/17/2013 07:29 AM, Linus Walleij wrote:

>> I think of_property_read_bool() will accept
>> xlnx,is-dual = <1>; to mean the same as xlnx,is-dual;
>> try it.
>
> First of all sorry for delay.
> You are right that of_property_read_bool()
> also accept xlnx,is-dual = <1>;
> but also accept and return 1 when xlnx,is-dual = <0>;
> which is incorrect behaviour.

OK but that is a coding issue, not a DT bindings design issue.
Can't we think a bit outside the box?
What about something like this:

static bool is_dual (struct device_node *np)
{
    struct property *prop = of_find_property(np, "xlnx,is-dual", NULL);
    int ret;
    u32 val;

    if (!prop)
        return false;

    ret = of_property_read_u32(np, "xlnx,is-dual", &val);
    if (ret < 0)
        return true; /* node exists but has no cells */

    return !!val;
}

Yours,
Linus Walleij