Re: [PATCH V2 1/2] pinctrl: enable pinmux for pxa series

[Linus Walleij]

On Tue, Dec 13, 2011 at 5:19 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Tuesday 13 December 2011, Haojian Zhuang wrote:

>> +#define GPIO0_GPIO106_PINS()                                         \
>> +     PINCTRL_PIN(0, "GPIO0"),        PINCTRL_PIN(1, "GPIO1"),        \
>> +     PINCTRL_PIN(2, "GPIO2"),        PINCTRL_PIN(3, "GPIO3"),        \
>> +     PINCTRL_PIN(4, "GPIO4"),        PINCTRL_PIN(5, "GPIO5"),        \
>> +     PINCTRL_PIN(6, "GPIO6"),        PINCTRL_PIN(7, "GPIO7"),        \
>> +     PINCTRL_PIN(8, "GPIO8"),        PINCTRL_PIN(9, "GPIO9"),        \
>> ...
>> +#define GPIO107_GPIO122_PINS()                                       \
>> +     PINCTRL_PIN(107, "GPIO107"),    PINCTRL_PIN(108, "GPIO108"),    \
>> +     PINCTRL_PIN(109, "GPIO109"),    PINCTRL_PIN(110, "GPIO110"),    \
>> +     PINCTRL_PIN(111, "GPIO111"),    PINCTRL_PIN(112, "GPIO112"),    \
>> ...
>> +#define GPIO123_GPIO127_PINS()                                       \
>> +     PINCTRL_PIN(123, "GPIO123"),    PINCTRL_PIN(124, "GPIO124"),    \
>> +     PINCTRL_PIN(125, "GPIO125"),    PINCTRL_PIN(126, "GPIO126"),    \
>> +     PINCTRL_PIN(127, "GPIO127")
>> ...
>> +#define GPIO128_GPIO168_PINS()                                       \
>> +     PINCTRL_PIN(128, "GPIO128"),    PINCTRL_PIN(129, "GPIO129"),    \
>> +     PINCTRL_PIN(130, "GPIO130"),    PINCTRL_PIN(131, "GPIO131"),    \
>> +     PINCTRL_PIN(132, "GPIO132"),    PINCTRL_PIN(133, "GPIO133"),    \
>
> This one seems more problematic to me. I think these endless macros
> very much inhibit readability and cause bloat in the code by duplicating
> the same data for each soc.
>
> Ideally, you should not be required to write such pointless lists, but
> I don't know if the pinctrl subsystem can provide a better alternative.

Hm I used to have a range registration macro a long time ago
but killed it for clarity, readability and keeping pins as part of the
struct pinctrl_desc device descriptor.

Maybe I should revisit that concept ...

I can easily think of static inlines in <linux/pinctrl/pinctrl.h>
that can conjure template-named pin ranges, like:

static inline struct pinctrl_pin_desc *
pinctrl_gen_pin_desc_range(unsigned start, unsigned end, const char *template)
{
    struct pinctrl_pin_desc *range;
    unsigned pins = end - start + 1;
    unsigned i;

    range = kmalloc(sizeof(pinctrl_pin_desc) * pins);
    if (!range)
         return -ENOMEM;

    for (i = 0; i < pins; i++) {
        range[i].number = start + i;
        range[i].name = kstrdup("%s%u", template, start + i);
        /* Error handling if kstrdup fails here */
    }
    return range;
}

That then also creates a need to catenate and combine some static
and some generated ranges into a total range and in the end add that
to the pinctrl_desc.pins member.

Would this work for you Haojian?

If you like it I can attempt to create a separate patch for this.

Yours,
Linus Walleij
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