Messages in this thread | | | Date | Wed, 4 Jan 2012 11:38:07 -0700 | From | Grant Likely <> | Subject | Re: [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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
| |