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linux/drivers/gpio/gpiolib-legacy.c

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gpio: Use SPDX header for core library Use the SPDX headers and cut down on boilerplate to indicate the license in the core gpiolib implementation. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-09-25 07:08:48 +00:00
// SPDX-License-Identifier: GPL-2.0
gpio: move integer GPIO support to its own file The old integer GPIO interface is, in effect, a privileged user of the gpiod interface. Reflect this fact further by moving legacy GPIO support into its own source file. This makes the code clearer and will allow us to disable legacy GPIO support in the (far) future. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-01 05:45:16 +00:00
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/gpio.h>
#include "gpiolib.h"
gpio: legacy: mark old interfaces as deprecated in kernel docs We've recently had someone try to use of_get_named_gpio() in new code. Mark legacy interfaces as deprecated in kernel docs to avoid any confusion. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-04 18:20:34 +00:00
/*
* **DEPRECATED** This function is deprecated and must not be used in new code.
*/
gpio: move integer GPIO support to its own file The old integer GPIO interface is, in effect, a privileged user of the gpiod interface. Reflect this fact further by moving legacy GPIO support into its own source file. This makes the code clearer and will allow us to disable legacy GPIO support in the (far) future. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-01 05:45:16 +00:00
void gpio_free(unsigned gpio)
{
gpiod_free(gpio_to_desc(gpio));
}
EXPORT_SYMBOL_GPL(gpio_free);
/**
* gpio_request_one - request a single GPIO with initial configuration
* @gpio: the GPIO number
* @flags: GPIO configuration as specified by GPIOF_*
* @label: a literal description string of this GPIO
gpio: legacy: mark old interfaces as deprecated in kernel docs We've recently had someone try to use of_get_named_gpio() in new code. Mark legacy interfaces as deprecated in kernel docs to avoid any confusion. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-04 18:20:34 +00:00
*
* **DEPRECATED** This function is deprecated and must not be used in new code.
gpio: move integer GPIO support to its own file The old integer GPIO interface is, in effect, a privileged user of the gpiod interface. Reflect this fact further by moving legacy GPIO support into its own source file. This makes the code clearer and will allow us to disable legacy GPIO support in the (far) future. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-01 05:45:16 +00:00
*/
int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
{
struct gpio_desc *desc;
int err;
gpio: fix deferred probe detection for legacy API Commit 14e85c0e69d5 ("gpio: remove gpio_descs global array") changed gpio_to_desc()'s behavior to return NULL not only for GPIOs numbers not in the valid range, but also for all GPIOs whose controller has not been probed yet. Although this behavior is more correct (nothing hints that these GPIO numbers will be populated later), this affects gpio_request() and gpio_request_one() which call gpiod_request() with a NULL descriptor, causing it to return -EINVAL instead of the expected -EPROBE_DEFER for a non-probed GPIO. gpiod_request() is only called with a descriptor obtained from gpio_to_desc() from these two functions, so address the issue there. Other ways to obtain GPIOs rely on well-defined mappings and can thus return -EPROBE_DEFER only for relevant GPIOs, and are thus not affected by this issue. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-12-02 14:15:05 +00:00
/* Compatibility: assume unavailable "valid" GPIOs will appear later */
gpiolib: Get rid of never false gpio_is_valid() calls In the cases when gpio_is_valid() is called with unsigned parameter the result is always true in the GPIO library code, hence the check for false won't ever be true. Get rid of such calls. While at it, move GPIO device base to be unsigned to clearly show it won't ever be negative. This requires a new definition for the maximum GPIO number in the system. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-02-21 21:31:56 +00:00
desc = gpio_to_desc(gpio);
if (!desc)
gpio: fix deferred probe detection for legacy API Commit 14e85c0e69d5 ("gpio: remove gpio_descs global array") changed gpio_to_desc()'s behavior to return NULL not only for GPIOs numbers not in the valid range, but also for all GPIOs whose controller has not been probed yet. Although this behavior is more correct (nothing hints that these GPIO numbers will be populated later), this affects gpio_request() and gpio_request_one() which call gpiod_request() with a NULL descriptor, causing it to return -EINVAL instead of the expected -EPROBE_DEFER for a non-probed GPIO. gpiod_request() is only called with a descriptor obtained from gpio_to_desc() from these two functions, so address the issue there. Other ways to obtain GPIOs rely on well-defined mappings and can thus return -EPROBE_DEFER only for relevant GPIOs, and are thus not affected by this issue. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-12-02 14:15:05 +00:00
return -EPROBE_DEFER;
Revert "gpiolib: Split GPIO flags parsing and GPIO configuration" This reverts commit 923b93e451db876d1479d3e4458fce14fec31d1c. Make sure consumers do not overwrite gpio flags for pins that have already been claimed. While adding support for gpio drivers to refuse a request using unsupported flags, the order of when the requested flag was checked and the new flags were applied was reversed to that consumers could overwrite flags for already requested gpios. This not only affects device-tree setups where two drivers could request the same gpio using conflicting configurations, but also allowed user space to clear gpio flags for already claimed pins simply by attempting to export them through the sysfs interface. By for example clearing the FLAG_ACTIVE_LOW flag this way, user space could effectively change the polarity of a signal. Reverting this change obviously prevents gpio drivers from doing sanity checks on the flags in their request callbacks. Fortunately only one recently added driver (gpio-tps65218 in v4.6) appears to do this, and a follow up patch could restore this functionality through a different interface. Cc: stable <stable@vger.kernel.org> # 4.4 Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-07-03 16:32:05 +00:00
err = gpiod_request(desc, label);
if (err)
return err;
gpio: Add support for GPIOF_ACTIVE_LOW to gpio_request_one functions The gpio include file and the gpio documentation declare and document GPIOF_ACTIVE_LOW as one of the flags to be passed to gpio_request_one and related functions. However, the flag is not evaluated or used. This can cause problems in at least two areas: First, the same API can be used to auto-export pins to user space. The missing support for GPIOF_ACTIVE_LOW results in unexpected behavior for such auto-exported pins. Second, the requested gpio pin can be convered for use by gpiod functions with gpio_to_desc(). While gpio API functions do not support GPIOF_ACTIVE_LOW, gpiod functions do, which again results in unexpected behavior. Check the flag in gpio_request_one and set the gpio internal flag FLAG_ACTIVE_LOW if it is set to address those problems. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-21 18:12:16 +00:00
if (flags & GPIOF_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
gpio: move integer GPIO support to its own file The old integer GPIO interface is, in effect, a privileged user of the gpiod interface. Reflect this fact further by moving legacy GPIO support into its own source file. This makes the code clearer and will allow us to disable legacy GPIO support in the (far) future. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-01 05:45:16 +00:00
if (flags & GPIOF_DIR_IN)
err = gpiod_direction_input(desc);
else
err = gpiod_direction_output_raw(desc,
(flags & GPIOF_INIT_HIGH) ? 1 : 0);
if (err)
goto free_gpio;
return 0;
free_gpio:
gpiod_free(desc);
return err;
}
EXPORT_SYMBOL_GPL(gpio_request_one);
gpio: legacy: mark old interfaces as deprecated in kernel docs We've recently had someone try to use of_get_named_gpio() in new code. Mark legacy interfaces as deprecated in kernel docs to avoid any confusion. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-04 18:20:34 +00:00
/*
* **DEPRECATED** This function is deprecated and must not be used in new code.
*/
gpio: move integer GPIO support to its own file The old integer GPIO interface is, in effect, a privileged user of the gpiod interface. Reflect this fact further by moving legacy GPIO support into its own source file. This makes the code clearer and will allow us to disable legacy GPIO support in the (far) future. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-01 05:45:16 +00:00
int gpio_request(unsigned gpio, const char *label)
{
gpiolib: Get rid of never false gpio_is_valid() calls In the cases when gpio_is_valid() is called with unsigned parameter the result is always true in the GPIO library code, hence the check for false won't ever be true. Get rid of such calls. While at it, move GPIO device base to be unsigned to clearly show it won't ever be negative. This requires a new definition for the maximum GPIO number in the system. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-02-21 21:31:56 +00:00
struct gpio_desc *desc;
gpio: fix deferred probe detection for legacy API Commit 14e85c0e69d5 ("gpio: remove gpio_descs global array") changed gpio_to_desc()'s behavior to return NULL not only for GPIOs numbers not in the valid range, but also for all GPIOs whose controller has not been probed yet. Although this behavior is more correct (nothing hints that these GPIO numbers will be populated later), this affects gpio_request() and gpio_request_one() which call gpiod_request() with a NULL descriptor, causing it to return -EINVAL instead of the expected -EPROBE_DEFER for a non-probed GPIO. gpiod_request() is only called with a descriptor obtained from gpio_to_desc() from these two functions, so address the issue there. Other ways to obtain GPIOs rely on well-defined mappings and can thus return -EPROBE_DEFER only for relevant GPIOs, and are thus not affected by this issue. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-12-02 14:15:05 +00:00
/* Compatibility: assume unavailable "valid" GPIOs will appear later */
gpiolib: Get rid of never false gpio_is_valid() calls In the cases when gpio_is_valid() is called with unsigned parameter the result is always true in the GPIO library code, hence the check for false won't ever be true. Get rid of such calls. While at it, move GPIO device base to be unsigned to clearly show it won't ever be negative. This requires a new definition for the maximum GPIO number in the system. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-02-21 21:31:56 +00:00
desc = gpio_to_desc(gpio);
if (!desc)
gpio: fix deferred probe detection for legacy API Commit 14e85c0e69d5 ("gpio: remove gpio_descs global array") changed gpio_to_desc()'s behavior to return NULL not only for GPIOs numbers not in the valid range, but also for all GPIOs whose controller has not been probed yet. Although this behavior is more correct (nothing hints that these GPIO numbers will be populated later), this affects gpio_request() and gpio_request_one() which call gpiod_request() with a NULL descriptor, causing it to return -EINVAL instead of the expected -EPROBE_DEFER for a non-probed GPIO. gpiod_request() is only called with a descriptor obtained from gpio_to_desc() from these two functions, so address the issue there. Other ways to obtain GPIOs rely on well-defined mappings and can thus return -EPROBE_DEFER only for relevant GPIOs, and are thus not affected by this issue. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-12-02 14:15:05 +00:00
return -EPROBE_DEFER;
return gpiod_request(desc, label);
gpio: move integer GPIO support to its own file The old integer GPIO interface is, in effect, a privileged user of the gpiod interface. Reflect this fact further by moving legacy GPIO support into its own source file. This makes the code clearer and will allow us to disable legacy GPIO support in the (far) future. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-01 05:45:16 +00:00
}
EXPORT_SYMBOL_GPL(gpio_request);
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