[PATCH 0/2] RFC: gpio: driver-local pin configuration

[Linus Walleij]

From: Linus Walleij <linus.walleij@xxxxxxxxxx>

This is a modification of the previous generic GPIO configuration
patch series.

I'm Cc:ing everyone involved in earlier discussions so we can
move forward on this consolidation work, lest I cannot convert
my drivers to use struct gpio_chip / gpiolib.

Background: Grant didn't like the idea of an ioctl() like
configuration function in the struct gpio_chip vtable, so we
decided to see if it was wiser to go back to the initial suggestion
of making it possible for drivers to dereference the struct
gpio_chip and perform driver-local operations via regular
function calls instead.

So in this patch set I expose gpio_to_chip(), then alter the
previous rewrite of the U300 GPIO driver to instead use a local
configuration function by wrapping the previously defined config
function into this:

/* External function to configure pins */
int u300_gpio_set_config(unsigned gpio, u16 param, unsigned long *data)
{
        struct gpio_chip *chip = gpio_to_chip(gpio);
        unsigned offset = gpio - chip->base;

        return u300_gpio_config(chip, offset, param, data);
}

This one is then exposed in the chip-specific header  in
<linux/gpio/u300.h>, and all the configuration defines that
were previously globally generic in <linux/gpio.h> are also
moved there and made driver-specific without any attempt of
generalizing this.

So for anything that is not currently in struct gpio_chip you
will have to implement something like this, per driver.

I'm open for keeping the generic config defines in <linux/gpio.h>
if Grant accepts that, it certainly will avoid some define
duplication in driver headers. Right now I stay away from the
gpiolib as much as I can.

Comments welcome!

Thanks,
Linus Walleij


Linus Walleij (2):
  gpio: expose gpio_to_chip()
  gpio/u300: rewrite gpio driver

 arch/arm/Kconfig                       |    2 +-
 arch/arm/mach-u300/Kconfig             |    1 +
 arch/arm/mach-u300/core.c              |   31 +-
 arch/arm/mach-u300/include/mach/gpio.h |  163 +-----
 arch/arm/mach-u300/include/mach/irqs.h |   25 +-
 drivers/gpio/Kconfig                   |    9 +
 drivers/gpio/gpio-u300.c               | 1176 +++++++++++++++++++-------------
 drivers/gpio/gpiolib.c                 |    2 +-
 include/asm-generic/gpio.h             |    1 +
 include/linux/gpio/u300.h              |   82 +++
 10 files changed, 833 insertions(+), 659 deletions(-)
 create mode 100644 include/linux/gpio/u300.h

-- 
1.7.3.2

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