Re: [PATCH v4 1/3] gpio / ACPI: add ACPI support

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Friday, November 30, 2012 11:20:57 AM Grant Likely wrote:
> On Tue, 20 Nov 2012 20:13:30 +0200, Mika Westerberg <mika.westerberg@linux.intel.com> wrote:
> > From: Mathias Nyman <mathias.nyman@linux.intel.com>
> > 
> > Add support for translating ACPI GPIO pin numbers to Linux GPIO API pins.
> > Needs a gpio controller driver with the acpi handler hook set.
> > 
> > Drivers can use acpi_get_gpio() to translate ACPI5 GpioIO and GpioInt
> > resources to Linux GPIO's.
> > 
> > Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> 
> Acked-by: Grant Likely <grant.likely@secretlab.ca>
> 
> This series goes together, so feel free to take it in whatever tree the
> rest are merged through.

I will, thanks a lot!

Rafael


> > ---
> >  drivers/gpio/Kconfig        |    4 ++++
> >  drivers/gpio/Makefile       |    1 +
> >  drivers/gpio/gpiolib-acpi.c |   54 +++++++++++++++++++++++++++++++++++++++++++
> >  include/linux/acpi_gpio.h   |   19 +++++++++++++++
> >  4 files changed, 78 insertions(+)
> >  create mode 100644 drivers/gpio/gpiolib-acpi.c
> >  create mode 100644 include/linux/acpi_gpio.h
> > 
> > diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> > index f11d8e3..5c9b384 100644
> > --- a/drivers/gpio/Kconfig
> > +++ b/drivers/gpio/Kconfig
> > @@ -49,6 +49,10 @@ config OF_GPIO
> >  	def_bool y
> >  	depends on OF
> >  
> > +config GPIO_ACPI
> > +	def_bool y
> > +	depends on ACPI
> > +
> >  config DEBUG_GPIO
> >  	bool "Debug GPIO calls"
> >  	depends on DEBUG_KERNEL
> > diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> > index 9aeed67..420dbac 100644
> > --- a/drivers/gpio/Makefile
> > +++ b/drivers/gpio/Makefile
> > @@ -4,6 +4,7 @@ ccflags-$(CONFIG_DEBUG_GPIO)	+= -DDEBUG
> >  
> >  obj-$(CONFIG_GPIOLIB)		+= gpiolib.o devres.o
> >  obj-$(CONFIG_OF_GPIO)		+= gpiolib-of.o
> > +obj-$(CONFIG_GPIO_ACPI)		+= gpiolib-acpi.o
> >  
> >  # Device drivers. Generally keep list sorted alphabetically
> >  obj-$(CONFIG_GPIO_GENERIC)	+= gpio-generic.o
> > diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
> > new file mode 100644
> > index 0000000..cbad6e9
> > --- /dev/null
> > +++ b/drivers/gpio/gpiolib-acpi.c
> > @@ -0,0 +1,54 @@
> > +/*
> > + * ACPI helpers for GPIO API
> > + *
> > + * Copyright (C) 2012, Intel Corporation
> > + * Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
> > + *          Mika Westerberg <mika.westerberg@linux.intel.com>
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + */
> > +
> > +#include <linux/errno.h>
> > +#include <linux/gpio.h>
> > +#include <linux/export.h>
> > +#include <linux/acpi_gpio.h>
> > +#include <linux/acpi.h>
> > +
> > +static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
> > +{
> > +	if (!gc->dev)
> > +		return false;
> > +
> > +	return ACPI_HANDLE(gc->dev) == data;
> > +}
> > +
> > +/**
> > + * acpi_get_gpio() - Translate ACPI GPIO pin to GPIO number usable with GPIO API
> > + * @path:	ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
> > + * @pin:	ACPI GPIO pin number (0-based, controller-relative)
> > + *
> > + * Returns GPIO number to use with Linux generic GPIO API, or errno error value
> > + */
> > +
> > +int acpi_get_gpio(char *path, int pin)
> > +{
> > +	struct gpio_chip *chip;
> > +	acpi_handle handle;
> > +	acpi_status status;
> > +
> > +	status = acpi_get_handle(NULL, path, &handle);
> > +	if (ACPI_FAILURE(status))
> > +		return -ENODEV;
> > +
> > +	chip = gpiochip_find(handle, acpi_gpiochip_find);
> > +	if (!chip)
> > +		return -ENODEV;
> > +
> > +	if (!gpio_is_valid(chip->base + pin))
> > +		return -EINVAL;
> > +
> > +	return chip->base + pin;
> > +}
> > +EXPORT_SYMBOL_GPL(acpi_get_gpio);
> > diff --git a/include/linux/acpi_gpio.h b/include/linux/acpi_gpio.h
> > new file mode 100644
> > index 0000000..91615a3
> > --- /dev/null
> > +++ b/include/linux/acpi_gpio.h
> > @@ -0,0 +1,19 @@
> > +#ifndef _LINUX_ACPI_GPIO_H_
> > +#define _LINUX_ACPI_GPIO_H_
> > +
> > +#include <linux/errno.h>
> > +
> > +#ifdef CONFIG_GPIO_ACPI
> > +
> > +int acpi_get_gpio(char *path, int pin);
> > +
> > +#else /* CONFIG_GPIO_ACPI */
> > +
> > +static inline int acpi_get_gpio(char *path, int pin)
> > +{
> > +	return -ENODEV;
> > +}
> > +
> > +#endif /* CONFIG_GPIO_ACPI */
> > +
> > +#endif /* _LINUX_ACPI_GPIO_H_ */
> 
> 
-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.