[PATCH] staging: comedi: comedi_usb.c: improve function documentation

From: Ian Abbott
Date: Wed Sep 30 2015 - 12:37:29 EST


Expand the descriptions of the functions and document the return values.

Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
drivers/staging/comedi/comedi_usb.c | 75 +++++++++++++++++++++++++------------
1 file changed, 52 insertions(+), 23 deletions(-)

diff --git a/drivers/staging/comedi/comedi_usb.c b/drivers/staging/comedi/comedi_usb.c
index 68b75e8..9c946d4 100644
--- a/drivers/staging/comedi/comedi_usb.c
+++ b/drivers/staging/comedi/comedi_usb.c
@@ -21,8 +21,14 @@
#include "comedi_usb.h"

/**
- * comedi_to_usb_interface() - comedi_device pointer to usb_interface pointer.
- * @dev: comedi_device struct
+ * comedi_to_usb_interface() - Return USB interface attached to COMEDI device
+ * @dev: COMEDI device.
+ *
+ * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
+ * a &struct device embedded in a &struct usb_interface.
+ *
+ * Return: Attached USB interface if @dev->hw_dev is non-%NULL.
+ * Return %NULL if @dev->hw_dev is %NULL.
*/
struct usb_interface *comedi_to_usb_interface(struct comedi_device *dev)
{
@@ -31,8 +37,14 @@ struct usb_interface *comedi_to_usb_interface(struct comedi_device *dev)
EXPORT_SYMBOL_GPL(comedi_to_usb_interface);

/**
- * comedi_to_usb_dev() - comedi_device pointer to usb_device pointer.
- * @dev: comedi_device struct
+ * comedi_to_usb_dev() - Return USB device attached to COMEDI device
+ * @dev: COMEDI device.
+ *
+ * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
+ * a &struct device embedded in a &struct usb_interface.
+ *
+ * Return: USB device to which the USB interface belongs if @dev->hw_dev is
+ * non-%NULL. Return %NULL if @dev->hw_dev is %NULL.
*/
struct usb_device *comedi_to_usb_dev(struct comedi_device *dev)
{
@@ -43,12 +55,19 @@ struct usb_device *comedi_to_usb_dev(struct comedi_device *dev)
EXPORT_SYMBOL_GPL(comedi_to_usb_dev);

/**
- * comedi_usb_auto_config() - Configure/probe a comedi USB driver.
- * @intf: usb_interface struct
- * @driver: comedi_driver struct
- * @context: driver specific data, passed to comedi_auto_config()
+ * comedi_usb_auto_config() - Configure/probe a USB COMEDI driver
+ * @intf: USB interface.
+ * @driver: Registered COMEDI driver.
+ * @context: Driver specific data, passed to comedi_auto_config().
*
- * Typically called from the usb_driver (*probe) function.
+ * Typically called from the usb_driver (*probe) function. Auto-configure a
+ * COMEDI device, using a pointer to the &struct device embedded in *@intf as
+ * the hardware device. The @context value gets passed through to @driver's
+ * "auto_attach" handler. The "auto_attach" handler may call
+ * comedi_to_usb_interface() on the passed in COMEDI device to recover @intf.
+ *
+ * Return: The result of calling comedi_auto_config() (%0 on success, or
+ * a negative error number on failure).
*/
int comedi_usb_auto_config(struct usb_interface *intf,
struct comedi_driver *driver,
@@ -59,10 +78,18 @@ int comedi_usb_auto_config(struct usb_interface *intf,
EXPORT_SYMBOL_GPL(comedi_usb_auto_config);

/**
- * comedi_pci_auto_unconfig() - Unconfigure/disconnect a comedi USB driver.
- * @intf: usb_interface struct
+ * comedi_usb_auto_unconfig() - Unconfigure/disconnect a USB COMEDI device
+ * @intf: USB interface.
*
* Typically called from the usb_driver (*disconnect) function.
+ * Auto-unconfigure a COMEDI device attached to this USB interface, using a
+ * pointer to the &struct device embedded in *@intf as the hardware device.
+ * The COMEDI driver's "detach" handler will be called during unconfiguration
+ * of the COMEDI device.
+ *
+ * Note that the COMEDI device may have already been unconfigured using the
+ * %COMEDI_DEVCONFIG ioctl, in which case this attempt to unconfigure it
+ * again should be ignored.
*/
void comedi_usb_auto_unconfig(struct usb_interface *intf)
{
@@ -71,13 +98,15 @@ void comedi_usb_auto_unconfig(struct usb_interface *intf)
EXPORT_SYMBOL_GPL(comedi_usb_auto_unconfig);

/**
- * comedi_usb_driver_register() - Register a comedi USB driver.
- * @comedi_driver: comedi_driver struct
- * @usb_driver: usb_driver struct
+ * comedi_usb_driver_register() - Register a USB COMEDI driver
+ * @comedi_driver: COMEDI driver to be registered.
+ * @usb_driver: USB driver to be registered.
+ *
+ * This function is called from the module_init() of USB COMEDI driver modules
+ * to register the COMEDI driver and the USB driver. Do not call it directly,
+ * use the module_comedi_usb_driver() helper macro instead.
*
- * This function is used for the module_init() of comedi USB drivers.
- * Do not call it directly, use the module_comedi_usb_driver() helper
- * macro instead.
+ * Return: %0 on success, or a negative error number on failure.
*/
int comedi_usb_driver_register(struct comedi_driver *comedi_driver,
struct usb_driver *usb_driver)
@@ -99,13 +128,13 @@ int comedi_usb_driver_register(struct comedi_driver *comedi_driver,
EXPORT_SYMBOL_GPL(comedi_usb_driver_register);

/**
- * comedi_usb_driver_unregister() - Unregister a comedi USB driver.
- * @comedi_driver: comedi_driver struct
- * @usb_driver: usb_driver struct
+ * comedi_usb_driver_unregister() - Unregister a USB COMEDI driver
+ * @comedi_driver: COMEDI driver to be registered.
+ * @usb_driver: USB driver to be registered.
*
- * This function is used for the module_exit() of comedi USB drivers.
- * Do not call it directly, use the module_comedi_usb_driver() helper
- * macro instead.
+ * This function is called from the module_exit() of USB COMEDI driver modules
+ * to unregister the USB driver and the COMEDI driver. Do not call it
+ * directly, use the module_comedi_usb_driver() helper macro instead.
*/
void comedi_usb_driver_unregister(struct comedi_driver *comedi_driver,
struct usb_driver *usb_driver)
--
2.5.3

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