diff options
| author | Johan Hovold <johan@kernel.org> | 2015-05-04 17:10:33 +0200 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2015-05-12 10:46:53 +0200 |
| commit | 166a85e44245d771bd7042f3ad72aa0e12bb53bd (patch) | |
| tree | a9fd0409715c50ff15d2314b2314b4358c754ffb /drivers/gpio/gpiolib-sysfs.c | |
| parent | 426577bd8846d67b735b3a4e8926ef00abb15297 (diff) | |
gpio: remove gpiod_sysfs_set_active_low
Remove gpiod_sysfs_set_active_low (and gpio_sysfs_set_active_low) which
allowed code to change the polarity of a gpio line even after it had
been exported through sysfs.
Drivers should not care, and generally does not know, about gpio-line
polarity which is a hardware feature that needs to be described by
firmware.
It is currently possible to define gpio-line polarity in device-tree and
acpi firmware or using platform data. Userspace can also change the
polarity through sysfs.
Note that drivers using the legacy gpio interface could still use
GPIOF_ACTIVE_LOW to change the polarity before exporting the gpio.
There are no in-kernel users of this interface.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Harry Wei <harryxiyou@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@zh-kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpiolib-sysfs.c')
| -rw-r--r-- | drivers/gpio/gpiolib-sysfs.c | 48 |
1 files changed, 2 insertions, 46 deletions
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index aeb73ef2955e..9dcd346a20fb 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -308,8 +308,8 @@ static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev, clear_bit(FLAG_ACTIVE_LOW, &desc->flags); /* reconfigure poll(2) support if enabled on one edge only */ - if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^ - !!test_bit(FLAG_TRIG_FALL, &desc->flags))) { + if (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^ + !!test_bit(FLAG_TRIG_FALL, &desc->flags)) { unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK; gpio_setup_irq(desc, dev, 0); @@ -681,50 +681,6 @@ int gpiod_export_link(struct device *dev, const char *name, EXPORT_SYMBOL_GPL(gpiod_export_link); /** - * gpiod_sysfs_set_active_low - set the polarity of gpio sysfs value - * @gpio: gpio to change - * @value: non-zero to use active low, i.e. inverted values - * - * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute. - * The GPIO does not have to be exported yet. If poll(2) support has - * been enabled for either rising or falling edge, it will be - * reconfigured to follow the new polarity. - * - * Returns zero on success, else an error. - */ -int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) -{ - struct device *dev = NULL; - int status = -EINVAL; - - if (!desc) { - pr_warn("%s: invalid GPIO\n", __func__); - return -EINVAL; - } - - mutex_lock(&sysfs_lock); - - if (test_bit(FLAG_EXPORT, &desc->flags)) { - dev = class_find_device(&gpio_class, NULL, desc, match_export); - if (dev == NULL) { - status = -ENODEV; - goto unlock; - } - } - - status = sysfs_set_active_low(desc, dev, value); - put_device(dev); -unlock: - mutex_unlock(&sysfs_lock); - - if (status) - gpiod_dbg(desc, "%s: status %d\n", __func__, status); - - return status; -} -EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low); - -/** * gpiod_unexport - reverse effect of gpio_export() * @gpio: gpio to make unavailable * |