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    SubjectRe: [PATCH] GPIO: add bindings for managed devices
    On Tue, Dec 20, 2011 at 09:40:21PM +0100, John Crispin wrote:
    > This patch adds 2 functions that allow managed devices to request GPIOs.
    > These GPIOs will then be managed by drivers/base/devres.c.
    >
    > Signed-off-by: John Crispin <blogic@openwrt.org>

    Applied, thanks

    g.

    > ---
    > drivers/gpio/Makefile | 2 +-
    > drivers/gpio/devres.c | 90 ++++++++++++++++++++++++++++++++++++++++++++
    > include/asm-generic/gpio.h | 4 ++
    > 3 files changed, 95 insertions(+), 1 deletions(-)
    > create mode 100644 drivers/gpio/devres.c
    >
    > diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
    > index dbcb0bc..da60964 100644
    > --- a/drivers/gpio/Makefile
    > +++ b/drivers/gpio/Makefile
    > @@ -2,7 +2,7 @@
    >
    > ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG
    >
    > -obj-$(CONFIG_GPIOLIB) += gpiolib.o
    > +obj-$(CONFIG_GPIOLIB) += gpiolib.o devres.o
    >
    > # Device drivers. Generally keep list sorted alphabetically
    > obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o
    > diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
    > new file mode 100644
    > index 0000000..3dd2939
    > --- /dev/null
    > +++ b/drivers/gpio/devres.c
    > @@ -0,0 +1,90 @@
    > +/*
    > + * drivers/gpio/devres.c - managed gpio resources
    > + *
    > + * 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.
    > + *
    > + * You should have received a copy of the GNU General Public License
    > + * along with this program; if not, write to the Free Software
    > + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
    > + *
    > + * This file is based on kernel/irq/devres.c
    > + *
    > + * Copyright (c) 2011 John Crispin <blogic@openwrt.org>
    > + */
    > +
    > +#include <linux/module.h>
    > +#include <linux/gpio.h>
    > +#include <linux/device.h>
    > +#include <linux/gfp.h>
    > +
    > +static void devm_gpio_release(struct device *dev, void *res)
    > +{
    > + unsigned *gpio = res;
    > +
    > + gpio_free(*gpio);
    > +}
    > +
    > +static int devm_gpio_match(struct device *dev, void *res, void *data)
    > +{
    > + unsigned *this = res, *gpio = data;
    > +
    > + return *this == *gpio;
    > +}
    > +
    > +/**
    > + * devm_gpio_request - request a gpio for a managed device
    > + * @dev: device to request the gpio for
    > + * @gpio: gpio to allocate
    > + * @label: the name of the requested gpio
    > + *
    > + * Except for the extra @dev argument, this function takes the
    > + * same arguments and performs the same function as
    > + * gpio_request(). GPIOs requested with this function will be
    > + * automatically freed on driver detach.
    > + *
    > + * If an GPIO allocated with this function needs to be freed
    > + * separately, devm_gpio_free() must be used.
    > + */
    > +
    > +int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
    > +{
    > + unsigned *dr;
    > + int rc;
    > +
    > + dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
    > + if (!dr)
    > + return -ENOMEM;
    > +
    > + rc = gpio_request(gpio, label);
    > + if (rc) {
    > + devres_free(dr);
    > + return rc;
    > + }
    > +
    > + *dr = gpio;
    > + devres_add(dev, dr);
    > +
    > + return 0;
    > +}
    > +EXPORT_SYMBOL(devm_gpio_request);
    > +
    > +/**
    > + * devm_gpio_free - free an interrupt
    > + * @dev: device to free gpio for
    > + * @gpio: gpio to free
    > + *
    > + * Except for the extra @dev argument, this function takes the
    > + * same arguments and performs the same function as gpio_free().
    > + * This function instead of gpio_free() should be used to manually
    > + * free GPIOs allocated with devm_gpio_request().
    > + */
    > +void devm_gpio_free(struct device *dev, unsigned int gpio)
    > +{
    > +
    > + WARN_ON(devres_destroy(dev, devm_gpio_release, devm_gpio_match,
    > + &gpio));
    > + gpio_free(gpio);
    > +}
    > +EXPORT_SYMBOL(devm_gpio_free);
    > diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
    > index 8c86210..8601a02 100644
    > --- a/include/asm-generic/gpio.h
    > +++ b/include/asm-generic/gpio.h
    > @@ -175,6 +175,10 @@ extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *labe
    > extern int gpio_request_array(const struct gpio *array, size_t num);
    > extern void gpio_free_array(const struct gpio *array, size_t num);
    >
    > +/* bindings for managed devices that want to request gpios */
    > +int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
    > +void devm_gpio_free(struct device *dev, unsigned int gpio);
    > +
    > #ifdef CONFIG_GPIO_SYSFS
    >
    > /*
    > --
    > 1.7.7.1
    >
    > --
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