Messages in this thread | | | Subject | Re: [PATCH 1/2] x86, gpio: Increase ARCH_NR_GPIOs to 512 | From | "H. Peter Anvin" <> | Date | Tue, 9 Sep 2014 00:41:47 -0700 |
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Isn't this exactly what ida is for?
Sent from my tablet, pardon any formatting problems.
> On Sep 9, 2014, at 0:24, Linus Walleij <linus.walleij@linaro.org> wrote: > > On Mon, Sep 8, 2014 at 1:47 PM, Mika Westerberg > <mika.westerberg@linux.intel.com> wrote: > >> Some newer Intel SoCs like Braswell already have more than 256 GPIOs >> available so the default limit is exceeded. In order to support these add >> back the custom GPIO header with limit of 512 GPIOs for x86. >> >> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> > > Argh! This is the kind of stuff I want to get rid of .... > > Preferably gpio should be a subsystem without a lot of hooks all over > the place with arch-specific modifications for this and that, including > the max number of GPIOs. > > I would actually prefer if you bump the value in > include/asm-generic/gpio.h to 512 over this. > > But better still, now that we have descriptors etc would be to define > some new per-arch selectable config option like > CONFIG_ONLY_DYNAMIC_GPIO that changes the GPIO > core to use something like a radix tree to store and retrieve > descriptors. > > I.e. in drivers/gpio/gpiolib.c get rid of this: > static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; > > Replace it with a radix tree of descriptors. > > This however makes it *impossible* to use things like desc_to_gpio() > and/or gpio_to_desc() so the code has to be augmented all over the > place to avoid any uses of GPIO numbers on that architecture, > but I am sure it *can* be done on pure ACPI or device tree > systems, and that's what we should aim for. > > Comments? > > Yours, > Linus Walleij
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