Re: [PATCH v5] GPIO: add support for 74x164 serial-in/parallel-out8-bit shift register

[Miguel Ojeda]

On Wed, Oct 20, 2010 at 9:52 AM, Miguel Ojeda
<miguel.ojeda.sandonis@xxxxxxxxx> wrote:
> On Wed, Oct 20, 2010 at 1:00 AM, Andrew Morton
> <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>> On Tue, 19 Oct 2010 09:26:42 +0200
>> Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx> wrote:
>>
>>> On Mon, Oct 18, 2010 at 9:35 PM, Florian Fainelli <florian@xxxxxxxxxxx> wrote:
>>> > From: Miguel Gaio <miguel.gaio@xxxxxxxxx>
>>> >
>>> > This patch adds support for generic 74x164 serial-in/parallel-out 8-bits
>>> > shift register. This driver can be used as a GPIO output expander.
>>> >
>>> ...
>>> > +struct gen_74x164_chip {
>>> > +       struct spi_device       *spi;
>>> > +       struct gpio_chip        gpio_chip;
>>> > +       struct mutex            lock;
>>> > +       u8                      port_config;
>>> > +};
>>> ...
>>> > +static void gen_74x164_set_value(struct gpio_chip *gc,
>>> > +               unsigned offset, int val)
>>> > +{
>>> > +       struct gen_74x164_chip *chip = gpio_to_chip(gc);
>>> > +       bool refresh;
>>> > +
>>> > +       mutex_lock(&chip->lock);
>>> > +       if (val)
>>> > +               chip->port_config |= (1 << offset);
>>> > +       else
>>> > +               chip->port_config &= ~(1 << offset);
>>>
>>> set_bit(), clear_bit() ?
>>
>> They're only to be used on `unsigned long' types, and `port_config' is
>> u8.
>>
>
> Right as always! Maybe BIT()? Don't we have a {SET,CLEAR}_BIT()-like
> macros somewhere?
>
> #define SET_BIT(var,nr) (var) |= BIT((nr))
> #define CLEAR_BIT(var,nr) (var) &= ~BIT((nr))
> #define PUT_BIT(var,nr,value) do { \
>        if ((value)) \
>                SET_BIT((var), (nr)); \
>        else \
>                CLEAR_BIT((var), (nr)); \
> } while(0)
>
> May I make a patch and try to see who could use it? I suppose a
> Coccinelle's semantic patch would be great here.
>

Well, after trying a few minutes spatch for my first time it has
already found a lot of places where the macros could be applied. I
will prepare a patch.
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