diff mbox series

[v2,2/2] gpiolib: Update the kernel documentation - add Return sections

Message ID 20240408231727.396452-3-andriy.shevchenko@linux.intel.com (mailing list archive)
State Handled Elsewhere, archived
Headers show
Series gpiolib: Fix gpio_lookup_flags mess and add Return sections | expand

Commit Message

Andy Shevchenko April 8, 2024, 11:12 p.m. UTC
$ scripts/kernel-doc -v -none -Wall drivers/gpio/gpiolib* 2>&1 | grep -w warning | wc -l
67

Fix these by adding Return sections. While at it, make sure all of
Return sections use the same style.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
---
 drivers/gpio/gpiolib-acpi.c   |  22 +++--
 drivers/gpio/gpiolib-cdev.c   |   8 +-
 drivers/gpio/gpiolib-devres.c |  44 +++++++++-
 drivers/gpio/gpiolib-legacy.c |   3 +
 drivers/gpio/gpiolib-of.c     |  48 ++++++++---
 drivers/gpio/gpiolib-swnode.c |   4 +-
 drivers/gpio/gpiolib-sysfs.c  |   6 +-
 drivers/gpio/gpiolib.c        | 157 +++++++++++++++++++++++++++-------
 8 files changed, 233 insertions(+), 59 deletions(-)

Comments

Andy Shevchenko April 9, 2024, 12:51 p.m. UTC | #1
On Tue, Apr 09, 2024 at 02:12:51AM +0300, Andy Shevchenko wrote:
> $ scripts/kernel-doc -v -none -Wall drivers/gpio/gpiolib* 2>&1 | grep -w warning | wc -l
> 67
> 
> Fix these by adding Return sections. While at it, make sure all of
> Return sections use the same style.

Since there shouldn't be hard dependency to the first one, can you consider
applying this one, so it unblocks me?

Thank you!
Bartosz Golaszewski April 9, 2024, 2:01 p.m. UTC | #2
On Tue, Apr 9, 2024 at 2:52 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Tue, Apr 09, 2024 at 02:12:51AM +0300, Andy Shevchenko wrote:
> > $ scripts/kernel-doc -v -none -Wall drivers/gpio/gpiolib* 2>&1 | grep -w warning | wc -l
> > 67
> >
> > Fix these by adding Return sections. While at it, make sure all of
> > Return sections use the same style.
>
> Since there shouldn't be hard dependency to the first one, can you consider
> applying this one, so it unblocks me?
>

I'm not sure what the resolution is for % and HTML <font> tags in the end?

Bart
Andy Shevchenko April 9, 2024, 2:06 p.m. UTC | #3
On Tue, Apr 09, 2024 at 04:01:43PM +0200, Bartosz Golaszewski wrote:
> On Tue, Apr 9, 2024 at 2:52 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> >
> > On Tue, Apr 09, 2024 at 02:12:51AM +0300, Andy Shevchenko wrote:
> > > $ scripts/kernel-doc -v -none -Wall drivers/gpio/gpiolib* 2>&1 | grep -w warning | wc -l
> > > 67
> > >
> > > Fix these by adding Return sections. While at it, make sure all of
> > > Return sections use the same style.
> >
> > Since there shouldn't be hard dependency to the first one, can you consider
> > applying this one, so it unblocks me?
> 
> I'm not sure what the resolution is for % and HTML <font> tags in the end?

Most of the constants are without %, so less churn now is to drop %.
If you think otherwise, please, fix it and I will rebase my patches later.
Bartosz Golaszewski April 9, 2024, 2:18 p.m. UTC | #4
On Tue, Apr 9, 2024 at 4:06 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Tue, Apr 09, 2024 at 04:01:43PM +0200, Bartosz Golaszewski wrote:
> > On Tue, Apr 9, 2024 at 2:52 PM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > >
> > > On Tue, Apr 09, 2024 at 02:12:51AM +0300, Andy Shevchenko wrote:
> > > > $ scripts/kernel-doc -v -none -Wall drivers/gpio/gpiolib* 2>&1 | grep -w warning | wc -l
> > > > 67
> > > >
> > > > Fix these by adding Return sections. While at it, make sure all of
> > > > Return sections use the same style.
> > >
> > > Since there shouldn't be hard dependency to the first one, can you consider
> > > applying this one, so it unblocks me?
> >
> > I'm not sure what the resolution is for % and HTML <font> tags in the end?
>
> Most of the constants are without %, so less churn now is to drop %.
> If you think otherwise, please, fix it and I will rebase my patches later.
>

I'm not sure I get the logic of it. If the kernel-wide standard is to
use %, then we should work towards using it across the GPIO code even
if we do it a few lines at a time instead of going backwards just for
consistency in drivers/gpio/, no? We don't need to fix everything now
but if you're touching this code, then I'd go with %.

Also: what about the s/error-code/error code/g issue? While we should
always say "active-low", I think error code looks better as two words.

Bart
Andy Shevchenko April 9, 2024, 2:29 p.m. UTC | #5
On Tue, Apr 09, 2024 at 04:18:46PM +0200, Bartosz Golaszewski wrote:
> On Tue, Apr 9, 2024 at 4:06 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > On Tue, Apr 09, 2024 at 04:01:43PM +0200, Bartosz Golaszewski wrote:
> > > On Tue, Apr 9, 2024 at 2:52 PM Andy Shevchenko
> > > <andriy.shevchenko@linux.intel.com> wrote:
> > > > On Tue, Apr 09, 2024 at 02:12:51AM +0300, Andy Shevchenko wrote:
> > > > > $ scripts/kernel-doc -v -none -Wall drivers/gpio/gpiolib* 2>&1 | grep -w warning | wc -l
> > > > > 67
> > > > >
> > > > > Fix these by adding Return sections. While at it, make sure all of
> > > > > Return sections use the same style.
> > > >
> > > > Since there shouldn't be hard dependency to the first one, can you consider
> > > > applying this one, so it unblocks me?
> > >
> > > I'm not sure what the resolution is for % and HTML <font> tags in the end?
> >
> > Most of the constants are without %, so less churn now is to drop %.
> > If you think otherwise, please, fix it and I will rebase my patches later.
> >
> 
> I'm not sure I get the logic of it. If the kernel-wide standard is to
> use %, then we should work towards using it across the GPIO code even
> if we do it a few lines at a time instead of going backwards just for
> consistency in drivers/gpio/, no? We don't need to fix everything now
> but if you're touching this code, then I'd go with %.
> 
> Also: what about the s/error-code/error code/g issue? While we should
> always say "active-low", I think error code looks better as two words.

I also have no much time for these details. :(
Let's drop this series then. Feel free to consider this as a problem report.
diff mbox series

Patch

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 7f140df40f35..9aac44f0816d 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -136,8 +136,12 @@  static int acpi_gpiochip_find(struct gpio_chip *gc, const void *data)
  * @path:	ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
  * @pin:	ACPI GPIO pin number (0-based, controller-relative)
  *
- * Return: GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
- * error value. Specifically returns %-EPROBE_DEFER if the referenced GPIO
+ * Returns:
+ * GPIO descriptor to use with Linux generic GPIO API.
+ * If the GPIO cannot be translated or there is an error an ERR_PTR is
+ * returned.
+ *
+ * Specifically returns -EPROBE_DEFER if the referenced GPIO
  * controller does not have GPIO chip registered at the moment. This is to
  * support probe deferral.
  */
@@ -207,6 +211,9 @@  EXPORT_SYMBOL_GPL(acpi_gpio_get_irq_resource);
  *			       I/O resource or return False if not.
  * @ares:	Pointer to the ACPI resource to fetch
  * @agpio:	Pointer to a &struct acpi_resource_gpio to store the output pointer
+ *
+ * Returns:
+ * true if GpioIo resource is found, false otherwise.
  */
 bool acpi_gpio_get_io_resource(struct acpi_resource *ares,
 			       struct acpi_resource_gpio **agpio)
@@ -859,7 +866,9 @@  static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode,
  * that case @index is used to select the GPIO entry in the property value
  * (in case of multiple).
  *
- * If the GPIO cannot be translated or there is an error, an ERR_PTR is
+ * Returns:
+ * GPIO descriptor to use with Linux generic GPIO API.
+ * If the GPIO cannot be translated or there is an error an ERR_PTR is
  * returned.
  *
  * Note: if the GPIO resource has multiple entries in the pin list, this
@@ -910,6 +919,8 @@  static struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
  * resource with the relevant information from a data-only ACPI firmware node
  * and uses that to obtain the GPIO descriptor to return.
  *
+ * Returns:
+ * GPIO descriptor to use with Linux generic GPIO API.
  * If the GPIO cannot be translated or there is an error an ERR_PTR is
  * returned.
  */
@@ -1023,7 +1034,8 @@  struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
  * The GPIO is considered wake capable if the GpioInt resource specifies
  * SharedAndWake or ExclusiveAndWake.
  *
- * Return: Linux IRQ number (> %0) on success, negative errno on failure.
+ * Returns:
+ * Linux IRQ number (> 0) on success, negative errno on failure.
  */
 int acpi_dev_gpio_irq_wake_get_by(struct acpi_device *adev, const char *name, int index,
 				  bool *wake_capable)
@@ -1406,7 +1418,7 @@  static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
  * @fwnode:	firmware node of the GPIO consumer
  * @con_id:	function within the GPIO consumer
  *
- * Return:
+ * Returns:
  * The number of GPIOs associated with a firmware node / function or %-ENOENT,
  * if no GPIO has been assigned to the requested function.
  */
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index d09c7d728365..23dad419cade 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -2726,7 +2726,9 @@  static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
  * gpio_chrdev_open() - open the chardev for ioctl operations
  * @inode: inode for this chardev
  * @file: file struct for storing private data
- * Returns 0 on success
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 static int gpio_chrdev_open(struct inode *inode, struct file *file)
 {
@@ -2792,7 +2794,9 @@  static int gpio_chrdev_open(struct inode *inode, struct file *file)
  * gpio_chrdev_release() - close chardev after ioctl operations
  * @inode: inode for this chardev
  * @file: file struct for storing private data
- * Returns 0 on success
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 static int gpio_chrdev_release(struct inode *inode, struct file *file)
 {
diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c
index 4987e62dcb3d..8a0371678ed2 100644
--- a/drivers/gpio/gpiolib-devres.c
+++ b/drivers/gpio/gpiolib-devres.c
@@ -52,6 +52,11 @@  static int devm_gpiod_match_array(struct device *dev, void *res, void *data)
  * Managed gpiod_get(). GPIO descriptors returned from this function are
  * automatically disposed on driver detach. See gpiod_get() for detailed
  * information about behavior and return values.
+ *
+ * Returns:
+ * The GPIO descriptor corresponding to the function @con_id of device
+ * dev, -ENOENT if no GPIO has been assigned to the requested function, or
+ * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
  */
 struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
 					      const char *con_id,
@@ -70,6 +75,11 @@  EXPORT_SYMBOL_GPL(devm_gpiod_get);
  * Managed gpiod_get_optional(). GPIO descriptors returned from this function
  * are automatically disposed on driver detach. See gpiod_get_optional() for
  * detailed information about behavior and return values.
+ *
+ * Returns:
+ * The GPIO descriptor corresponding to the function @con_id of device
+ * dev, NULL if no GPIO has been assigned to the requested function, or
+ * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
  */
 struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
 						       const char *con_id,
@@ -89,6 +99,11 @@  EXPORT_SYMBOL_GPL(devm_gpiod_get_optional);
  * Managed gpiod_get_index(). GPIO descriptors returned from this function are
  * automatically disposed on driver detach. See gpiod_get_index() for detailed
  * information about behavior and return values.
+ *
+ * Returns:
+ * The GPIO descriptor corresponding to the function @con_id of device
+ * dev, -ENOENT if no GPIO has been assigned to the requested function, or
+ * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
  */
 struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
 						    const char *con_id,
@@ -141,8 +156,10 @@  EXPORT_SYMBOL_GPL(devm_gpiod_get_index);
  * GPIO descriptors returned from this function are automatically disposed on
  * driver detach.
  *
- * On successful request the GPIO pin is configured in accordance with
- * provided @flags.
+ * Returns:
+ * The GPIO descriptor corresponding to the function @con_id of device
+ * dev, -ENOENT if no GPIO has been assigned to the requested function, or
+ * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
  */
 struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
 					      struct fwnode_handle *fwnode,
@@ -182,6 +199,11 @@  EXPORT_SYMBOL_GPL(devm_fwnode_gpiod_get_index);
  * function are automatically disposed on driver detach. See
  * gpiod_get_index_optional() for detailed information about behavior and
  * return values.
+ *
+ * Returns:
+ * The GPIO descriptor corresponding to the function @con_id of device
+ * dev, NULL if no GPIO has been assigned to the requested function, or
+ * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
  */
 struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
 							     const char *con_id,
@@ -207,6 +229,12 @@  EXPORT_SYMBOL_GPL(devm_gpiod_get_index_optional);
  * Managed gpiod_get_array(). GPIO descriptors returned from this function are
  * automatically disposed on driver detach. See gpiod_get_array() for detailed
  * information about behavior and return values.
+ *
+ * Returns:
+ * The GPIO descriptors corresponding to the function @con_id of device
+ * dev, -ENOENT if no GPIO has been assigned to the requested function,
+ * or another IS_ERR() code if an error occurred while trying to acquire
+ * the GPIOs.
  */
 struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
 						     const char *con_id,
@@ -243,6 +271,12 @@  EXPORT_SYMBOL_GPL(devm_gpiod_get_array);
  * function are automatically disposed on driver detach.
  * See gpiod_get_array_optional() for detailed information about behavior and
  * return values.
+ *
+ * Returns:
+ * The GPIO descriptors corresponding to the function @con_id of device
+ * dev, NULL if no GPIO has been assigned to the requested function,
+ * or another IS_ERR() code if an error occurred while trying to acquire
+ * the GPIOs.
  */
 struct gpio_descs *__must_check
 devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
@@ -337,6 +371,9 @@  static void devm_gpio_release(struct device *dev, void *res)
  *      same arguments and performs the same function as
  *      gpio_request().  GPIOs requested with this function will be
  *      automatically freed on driver detach.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
 {
@@ -366,6 +403,9 @@  EXPORT_SYMBOL_GPL(devm_gpio_request);
  *	@gpio:	the GPIO number
  *	@flags:	GPIO configuration as specified by GPIOF_*
  *	@label:	a literal description string of this GPIO
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int devm_gpio_request_one(struct device *dev, unsigned gpio,
 			  unsigned long flags, const char *label)
diff --git a/drivers/gpio/gpiolib-legacy.c b/drivers/gpio/gpiolib-legacy.c
index 616d60187f85..0774afa8abde 100644
--- a/drivers/gpio/gpiolib-legacy.c
+++ b/drivers/gpio/gpiolib-legacy.c
@@ -22,6 +22,9 @@  EXPORT_SYMBOL_GPL(gpio_free);
  * @label:	a literal description string of this GPIO
  *
  * **DEPRECATED** This function is deprecated and must not be used in new code.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
 {
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 2f251b08173c..495dc24275b9 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -46,16 +46,19 @@  enum of_gpio_flags {
  * @propname:	property name containing gpio specifier(s)
  *
  * The function returns the count of GPIOs specified for a node.
- * Note that the empty GPIO specifiers count too. Returns either
- *   Number of gpios defined in property,
- *   -EINVAL for an incorrectly formed gpios property, or
- *   -ENOENT for a missing gpios property
+ * NOTE: The empty GPIO specifiers count too.
  *
- * Example:
- * gpios = <0
- *          &gpio1 1 2
- *          0
- *          &gpio2 3 4>;
+ * Returns:
+ * Either number of GPIOs defined in the property, or
+ * *  -EINVAL for an incorrectly formed "gpios" property, or
+ * *  -ENOENT for a missing "gpios" property.
+ *
+ * Example::
+ *
+ *     gpios = <0
+ *              &gpio1 1 2
+ *              0
+ *              &gpio2 3 4>;
  *
  * The above example defines four GPIOs, two of which are not specified.
  * This function will return '4'
@@ -77,6 +80,11 @@  static int of_gpio_named_count(const struct device_node *np,
  * "gpios" for the chip select lines. If we detect this, we redirect
  * the counting of "cs-gpios" to count "gpios" transparent to the
  * driver.
+ *
+ * Returns:
+ * Either number of GPIOs defined in the property, or
+ * *  -EINVAL for an incorrectly formed "gpios" property, or
+ * *  -ENOENT for a missing "gpios" property.
  */
 static int of_gpio_spi_cs_get_count(const struct device_node *np,
 				    const char *con_id)
@@ -365,7 +373,8 @@  static void of_gpio_flags_quirks(const struct device_node *np,
  * @index:	index of the GPIO
  * @flags:	a flags pointer to fill in
  *
- * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
+ * Returns:
+ * GPIO descriptor to use with Linux GPIO API, or one of the errno
  * value on the error condition. If @flags is not NULL the function also fills
  * in flags for the GPIO.
  */
@@ -417,7 +426,8 @@  static struct gpio_desc *of_get_named_gpiod_flags(const struct device_node *np,
  *
  * **DEPRECATED** This function is deprecated and must not be used in new code.
  *
- * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
+ * Returns:
+ * GPIO number to use with Linux generic GPIO API, or one of the errno
  * value on the error condition.
  */
 int of_get_named_gpio(const struct device_node *np, const char *propname,
@@ -711,7 +721,8 @@  struct gpio_desc *of_find_gpio(struct device_node *np, const char *con_id,
  * @lflags:	bitmask of GPIO_* values - returned from *_find_gpio()
  * @dflags:	gpiod_flags - optional GPIO initialization flags
  *
- * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
+ * Returns:
+ * GPIO descriptor to use with Linux GPIO API, or one of the errno
  * value on the error condition.
  */
 static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
@@ -779,7 +790,8 @@  static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
  * @chip:	gpio chip to act on
  * @hog:	device node describing the hogs
  *
- * Returns error if it fails otherwise 0 on success.
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog)
 {
@@ -813,7 +825,9 @@  static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog)
  *
  * This is only used by of_gpiochip_add to request/set GPIO initial
  * configuration.
- * It returns error if it fails otherwise 0 on success.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
 {
@@ -926,6 +940,9 @@  struct notifier_block gpio_of_notifier = {
  * This is simple translation function, suitable for the most 1:1 mapped
  * GPIO chips. This function performs only one sanity check: whether GPIO
  * is less than ngpios (that is specified in the gpio_chip).
+ *
+ * Returns:
+ * GPIO number (>= 0) on success, negative errno on failure.
  */
 static int of_gpio_simple_xlate(struct gpio_chip *gc,
 				const struct of_phandle_args *gpiospec,
@@ -975,6 +992,9 @@  static int of_gpio_simple_xlate(struct gpio_chip *gc,
  * If succeeded, this function will map bank's memory and will
  * do all necessary work for you. Then you'll able to use .regs
  * to manage GPIOs from the callbacks.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int of_mm_gpiochip_add_data(struct device_node *np,
 			    struct of_mm_gpio_chip *mm_gc,
diff --git a/drivers/gpio/gpiolib-swnode.c b/drivers/gpio/gpiolib-swnode.c
index fa52bdb1a29a..7298f1247dd3 100644
--- a/drivers/gpio/gpiolib-swnode.c
+++ b/drivers/gpio/gpiolib-swnode.c
@@ -96,8 +96,8 @@  struct gpio_desc *swnode_find_gpio(struct fwnode_handle *fwnode,
  *		system-global GPIOs
  * @con_id:	function within the GPIO consumer
  *
- * Return:
- * The number of GPIOs associated with a device / function or %-ENOENT,
+ * Returns:
+ * The number of GPIOs associated with a device / function or -ENOENT,
  * if no GPIO has been assigned to the requested function.
  */
 int swnode_gpio_count(const struct fwnode_handle *fwnode, const char *con_id)
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 6853ecd98bcb..772ad900ffac 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -568,7 +568,8 @@  static struct class gpio_class = {
  * will see "direction" sysfs attribute which may be used to change
  * the gpio's direction.  A "value" attribute will always be provided.
  *
- * Returns zero on success, else an error.
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
 {
@@ -667,7 +668,8 @@  static int match_export(struct device *dev, const void *desc)
  * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN
  * node. Caller is responsible for unlinking.
  *
- * Returns zero on success, else an error.
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_export_link(struct device *dev, const char *name,
 		      struct gpio_desc *desc)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index cb66506bebde..105029627d39 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -216,6 +216,9 @@  EXPORT_SYMBOL_GPL(desc_to_gpio);
  * This function is unsafe and should not be used. Using the chip address
  * without taking the SRCU read lock may result in dereferencing a dangling
  * pointer.
+ *
+ * Returns:
+ * Address of the GPIO chip backing this device.
  */
 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
 {
@@ -326,7 +329,8 @@  static int gpiochip_find_base_unlocked(int ngpio)
  * gpiod_get_direction - return the current direction of a GPIO
  * @desc:	GPIO to get the direction of
  *
- * Returns 0 for output, 1 for input, or an error code in case of error.
+ * Returns:
+ * 0 for output, 1 for input, or an error code in case of error.
  *
  * This function may sleep if gpiod_cansleep() is true.
  */
@@ -383,8 +387,8 @@  EXPORT_SYMBOL_GPL(gpiod_get_direction);
  * Add a new chip to the global chips list, keeping the list of chips sorted
  * by range(means [base, base + ngpio - 1]) order.
  *
- * Return -EBUSY if the new chip overlaps with some other chip's integer
- * space.
+ * Returns:
+ * -EBUSY if the new chip overlaps with some other chip's integer space.
  */
 static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev)
 {
@@ -1504,6 +1508,9 @@  static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
  * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
  * used as the activate function for the &struct irq_domain_ops. The host_data
  * for the IRQ domain must be the &struct gpio_chip.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 static int gpiochip_irq_domain_activate(struct irq_domain *domain,
 					struct irq_data *data, bool reserve)
@@ -1648,6 +1655,9 @@  static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
  * This function will set up the mapping for a certain IRQ line on a
  * gpiochip by assigning the gpiochip as chip data, and using the irqchip
  * stored inside the gpiochip.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
 			    irq_hw_number_t hwirq)
@@ -1882,6 +1892,9 @@  static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc,
  * @gc: the GPIO chip to add the IRQ chip to
  * @lock_key: lockdep class for IRQ lock
  * @request_key: lockdep class for IRQ request
+ *
+ * Returns:
+ * 0 on success, or a negative errno on failure.
  */
 static int gpiochip_add_irqchip(struct gpio_chip *gc,
 				struct lock_class_key *lock_key,
@@ -2017,6 +2030,9 @@  static void gpiochip_irqchip_remove(struct gpio_chip *gc)
  * @domain: the irqdomain to add to the gpiochip
  *
  * This function adds an IRQ domain to the gpiochip.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
 				struct irq_domain *domain)
@@ -2053,6 +2069,9 @@  static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
  * gpiochip_generic_request() - request the gpio function for a pin
  * @gc: the gpiochip owning the GPIO
  * @offset: the offset of the GPIO to request for GPIO function
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
 {
@@ -2086,6 +2105,9 @@  EXPORT_SYMBOL_GPL(gpiochip_generic_free);
  * @gc: the gpiochip owning the GPIO
  * @offset: the offset of the GPIO to apply the configuration
  * @config: the configuration to be applied
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
 			    unsigned long config)
@@ -2112,6 +2134,9 @@  EXPORT_SYMBOL_GPL(gpiochip_generic_config);
  * pinctrl driver is DEPRECATED. Please see Section 2.1 of
  * Documentation/devicetree/bindings/gpio/gpio.txt on how to
  * bind pinctrl and gpio drivers via the "gpio-ranges" property.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
 			struct pinctrl_dev *pctldev,
@@ -2163,13 +2188,13 @@  EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
  * @npins: the number of pins from the offset of each pin space (GPIO and
  *	pin controller) to accumulate in this range
  *
- * Returns:
- * 0 on success, or a negative error-code on failure.
- *
  * Calling this function directly from a DeviceTree-supported
  * pinctrl driver is DEPRECATED. Please see Section 2.1 of
  * Documentation/devicetree/bindings/gpio/gpio.txt on how to
  * bind pinctrl and gpio drivers via the "gpio-ranges" property.
+ *
+ * Returns:
+ * 0 on success, or a negative errno on failure.
  */
 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
 			   unsigned int gpio_offset, unsigned int pin_offset,
@@ -2573,7 +2598,8 @@  static int gpio_set_bias(struct gpio_desc *desc)
  * The function calls the certain GPIO driver to set debounce timeout
  * in the hardware.
  *
- * Returns 0 on success, or negative error code otherwise.
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
 {
@@ -2589,7 +2615,8 @@  int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
  * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
  * be called safely on it.
  *
- * Return 0 in case of success, else an error code.
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_direction_input(struct gpio_desc *desc)
 {
@@ -2696,7 +2723,8 @@  static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
  * be called safely on it. The initial value of the output must be specified
  * as raw value on the physical line without regard for the ACTIVE_LOW status.
  *
- * Return 0 in case of success, else an error code.
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
 {
@@ -2715,7 +2743,8 @@  EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
  * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
  * account.
  *
- * Return 0 in case of success, else an error code.
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_direction_output(struct gpio_desc *desc, int value)
 {
@@ -2788,7 +2817,8 @@  EXPORT_SYMBOL_GPL(gpiod_direction_output);
  * @desc: GPIO to enable.
  * @flags: Flags related to GPIO edge.
  *
- * Return 0 in case of success, else negative error code.
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
 {
@@ -2820,7 +2850,8 @@  EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns);
  * @desc: GPIO to disable.
  * @flags: Flags related to GPIO edge, same value as used during enable call.
  *
- * Return 0 in case of success, else negative error code.
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
 {
@@ -2912,7 +2943,8 @@  int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
  * gpiod_is_active_low - test whether a GPIO is active-low or not
  * @desc: the gpio descriptor to test
  *
- * Returns 1 if the GPIO is active-low, 0 otherwise.
+ * Returns:
+ * 1 if the GPIO is active-low, 0 otherwise.
  */
 int gpiod_is_active_low(const struct gpio_desc *desc)
 {
@@ -3127,7 +3159,8 @@  int gpiod_get_array_value_complex(bool raw, bool can_sleep,
  * gpiod_get_raw_value() - return a gpio's raw value
  * @desc: gpio whose value will be returned
  *
- * Return the GPIO's raw value, i.e. the value of the physical line disregarding
+ * Returns:
+ * The GPIO's raw value, i.e. the value of the physical line disregarding
  * its ACTIVE_LOW status, or negative errno on failure.
  *
  * This function can be called from contexts where we cannot sleep, and will
@@ -3146,7 +3179,8 @@  EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
  * gpiod_get_value() - return a gpio's value
  * @desc: gpio whose value will be returned
  *
- * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
+ * Returns:
+ * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
  * account, or negative errno on failure.
  *
  * This function can be called from contexts where we cannot sleep, and will
@@ -3179,11 +3213,13 @@  EXPORT_SYMBOL_GPL(gpiod_get_value);
  * @value_bitmap: bitmap to store the read values
  *
  * Read the raw values of the GPIOs, i.e. the values of the physical lines
- * without regard for their ACTIVE_LOW status.  Return 0 in case of success,
- * else an error code.
+ * without regard for their ACTIVE_LOW status.
  *
  * This function can be called from contexts where we cannot sleep,
  * and it will complain if the GPIO chip functions potentially sleep.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_get_raw_array_value(unsigned int array_size,
 			      struct gpio_desc **desc_array,
@@ -3206,10 +3242,13 @@  EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
  * @value_bitmap: bitmap to store the read values
  *
  * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
- * into account.  Return 0 in case of success, else an error code.
+ * into account.
  *
  * This function can be called from contexts where we cannot sleep,
  * and it will complain if the GPIO chip functions potentially sleep.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_get_array_value(unsigned int array_size,
 			  struct gpio_desc **desc_array,
@@ -3497,6 +3536,9 @@  EXPORT_SYMBOL_GPL(gpiod_set_value);
  *
  * This function can be called from contexts where we cannot sleep, and will
  * complain if the GPIO chip functions potentially sleep.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_set_raw_array_value(unsigned int array_size,
 			      struct gpio_desc **desc_array,
@@ -3522,6 +3564,9 @@  EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
  *
  * This function can be called from contexts where we cannot sleep, and will
  * complain if the GPIO chip functions potentially sleep.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_set_array_value(unsigned int array_size,
 			  struct gpio_desc **desc_array,
@@ -3540,6 +3585,8 @@  EXPORT_SYMBOL_GPL(gpiod_set_array_value);
  * gpiod_cansleep() - report whether gpio value access may sleep
  * @desc: gpio to check
  *
+ * Returns:
+ * 0 for non-sleepable, 1 for sleepable, or an error code in case of error.
  */
 int gpiod_cansleep(const struct gpio_desc *desc)
 {
@@ -3552,6 +3599,9 @@  EXPORT_SYMBOL_GPL(gpiod_cansleep);
  * gpiod_set_consumer_name() - set the consumer name for the descriptor
  * @desc: gpio to set the consumer name on
  * @name: the new consumer name
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
 {
@@ -3565,8 +3615,8 @@  EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
  * gpiod_to_irq() - return the IRQ corresponding to a GPIO
  * @desc: gpio whose IRQ will be returned (already requested)
  *
- * Return the IRQ corresponding to the passed GPIO, or an error code in case of
- * error.
+ * Returns:
+ * The IRQ corresponding to the passed GPIO, or an error code in case of error.
  */
 int gpiod_to_irq(const struct gpio_desc *desc)
 {
@@ -3620,6 +3670,9 @@  EXPORT_SYMBOL_GPL(gpiod_to_irq);
  *
  * This is used directly by GPIO drivers that want to lock down
  * a certain GPIO line to be used for IRQs.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
 {
@@ -3771,7 +3824,8 @@  EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
  * gpiod_get_raw_value_cansleep() - return a gpio's raw value
  * @desc: gpio whose value will be returned
  *
- * Return the GPIO's raw value, i.e. the value of the physical line disregarding
+ * Returns:
+ * The GPIO's raw value, i.e. the value of the physical line disregarding
  * its ACTIVE_LOW status, or negative errno on failure.
  *
  * This function is to be called from contexts that can sleep.
@@ -3788,7 +3842,8 @@  EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
  * gpiod_get_value_cansleep() - return a gpio's value
  * @desc: gpio whose value will be returned
  *
- * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
+ * Returns:
+ * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
  * account, or negative errno on failure.
  *
  * This function is to be called from contexts that can sleep.
@@ -3818,10 +3873,12 @@  EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
  * @value_bitmap: bitmap to store the read values
  *
  * Read the raw values of the GPIOs, i.e. the values of the physical lines
- * without regard for their ACTIVE_LOW status.  Return 0 in case of success,
- * else an error code.
+ * without regard for their ACTIVE_LOW status.
  *
  * This function is to be called from contexts that can sleep.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
 				       struct gpio_desc **desc_array,
@@ -3845,9 +3902,12 @@  EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
  * @value_bitmap: bitmap to store the read values
  *
  * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
- * into account.  Return 0 in case of success, else an error code.
+ * into account.
  *
  * This function is to be called from contexts that can sleep.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_get_array_value_cansleep(unsigned int array_size,
 				   struct gpio_desc **desc_array,
@@ -3910,6 +3970,9 @@  EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
  * without regard for their ACTIVE_LOW status.
  *
  * This function is to be called from contexts that can sleep.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
 				       struct gpio_desc **desc_array,
@@ -3952,6 +4015,9 @@  void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
  * into account.
  *
  * This function is to be called from contexts that can sleep.
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_set_array_value_cansleep(unsigned int array_size,
 				   struct gpio_desc **desc_array,
@@ -4285,9 +4351,12 @@  EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
 
 /**
  * gpiod_count - return the number of GPIOs associated with a device / function
- *		or -ENOENT if no GPIO has been assigned to the requested function
  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
  * @con_id:	function within the GPIO consumer
+ *
+ * Returns:
+ * The number of GPIOs associated with a device / function or -ENOENT if no
+ * GPIO has been assigned to the requested function.
  */
 int gpiod_count(struct device *dev, const char *con_id)
 {
@@ -4314,7 +4383,8 @@  EXPORT_SYMBOL_GPL(gpiod_count);
  * @con_id:	function within the GPIO consumer
  * @flags:	optional GPIO initialization flags
  *
- * Return the GPIO descriptor corresponding to the function con_id of device
+ * Returns:
+ * The GPIO descriptor corresponding to the function @con_id of device
  * dev, -ENOENT if no GPIO has been assigned to the requested function, or
  * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
  */
@@ -4334,6 +4404,11 @@  EXPORT_SYMBOL_GPL(gpiod_get);
  * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
  * the requested function it will return NULL. This is convenient for drivers
  * that need to handle optional GPIOs.
+ *
+ * Returns:
+ * The GPIO descriptor corresponding to the function @con_id of device
+ * dev, NULL if no GPIO has been assigned to the requested function, or
+ * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
  */
 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
 						  const char *con_id,
@@ -4351,7 +4426,8 @@  EXPORT_SYMBOL_GPL(gpiod_get_optional);
  * @lflags:	bitmask of GPIO_* values - returned from *_find_gpio()
  * @dflags:	gpiod_flags - optional GPIO initialization flags
  *
- * Return 0 on success, -ENOENT if no GPIO has been assigned to the
+ * Returns:
+ * 0 on success, -ENOENT if no GPIO has been assigned to the
  * requested function and/or index, or another IS_ERR() code if an error
  * occurred while trying to acquire the GPIO.
  */
@@ -4426,7 +4502,8 @@  int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
  * This variant of gpiod_get() allows to access GPIOs other than the first
  * defined one for functions that define several GPIOs.
  *
- * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
+ * Returns:
+ * A valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
  * requested function and/or index, or another IS_ERR() code if an error
  * occurred while trying to acquire the GPIO.
  */
@@ -4454,6 +4531,11 @@  EXPORT_SYMBOL_GPL(gpiod_get_index);
  * This is equivalent to gpiod_get_index(), except that when no GPIO with the
  * specified index was assigned to the requested function it will return NULL.
  * This is convenient for drivers that need to handle optional GPIOs.
+ *
+ * Returns:
+ * A valid GPIO descriptor, NULL if no GPIO has been assigned to the
+ * requested function and/or index, or another IS_ERR() code if an error
+ * occurred while trying to acquire the GPIO.
  */
 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
 							const char *con_id,
@@ -4476,6 +4558,9 @@  EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
  * @name:	gpio line name
  * @lflags:	bitmask of GPIO_* values - returned from *_find_gpio()
  * @dflags:	gpiod_flags - optional GPIO initialization flags
+ *
+ * Returns:
+ * 0 on success, or negative errno on failure.
  */
 int gpiod_hog(struct gpio_desc *desc, const char *name,
 	      unsigned long lflags, enum gpiod_flags dflags)
@@ -4532,9 +4617,11 @@  static void gpiochip_free_hogs(struct gpio_chip *gc)
  *
  * This function acquires all the GPIOs defined under a given function.
  *
- * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
- * no GPIO has been assigned to the requested function, or another IS_ERR()
- * code if an error occurred while trying to acquire the GPIOs.
+ * Returns:
+ * The GPIO descriptors corresponding to the function @con_id of device
+ * dev, -ENOENT if no GPIO has been assigned to the requested function,
+ * or another IS_ERR() code if an error occurred while trying to acquire
+ * the GPIOs.
  */
 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
 						const char *con_id,
@@ -4660,6 +4747,12 @@  EXPORT_SYMBOL_GPL(gpiod_get_array);
  *
  * This is equivalent to gpiod_get_array(), except that when no GPIO was
  * assigned to the requested function it will return NULL.
+ *
+ * Returns:
+ * The GPIO descriptors corresponding to the function @con_id of device
+ * dev, NULL if no GPIO has been assigned to the requested function,
+ * or another IS_ERR() code if an error occurred while trying to acquire
+ * the GPIOs.
  */
 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
 							const char *con_id,