From 7a064fd13f44eb1acf2d525765fab55c7a3c3bf1 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Wed, 23 Sep 2015 19:35:56 +0100 Subject: [PATCH] staging: comedi: comedi_pci.c: improve function documentation Expand the descriptions of the functions and document the return values. Signed-off-by: Ian Abbott Reviewed-by: H Hartley Sweeten Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/comedi_pci.c | 108 ++++++++++++++++++++-------- 1 file changed, 80 insertions(+), 28 deletions(-) diff --git a/drivers/staging/comedi/comedi_pci.c b/drivers/staging/comedi/comedi_pci.c index 027f0f4e59c1..0601049d8923 100644 --- a/drivers/staging/comedi/comedi_pci.c +++ b/drivers/staging/comedi/comedi_pci.c @@ -22,8 +22,14 @@ #include "comedi_pci.h" /** - * comedi_to_pci_dev() - comedi_device pointer to pci_dev pointer. - * @dev: comedi_device struct + * comedi_to_pci_dev() - Return PCI 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 pci_dev. + * + * Returns: Attached PCI device if @dev->hw_dev is non-%NULL. + * Returns %NULL if @dev->hw_dev is %NULL. */ struct pci_dev *comedi_to_pci_dev(struct comedi_device *dev) { @@ -32,8 +38,22 @@ struct pci_dev *comedi_to_pci_dev(struct comedi_device *dev) EXPORT_SYMBOL_GPL(comedi_to_pci_dev); /** - * comedi_pci_enable() - Enable the PCI device and request the regions. - * @dev: comedi_device struct + * comedi_pci_enable() - Enable the PCI device and request the regions + * @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 pci_dev. Enable the PCI device + * and request its regions. Set @dev->ioenabled to %true if successful, + * otherwise undo what was done. + * + * Calls to comedi_pci_enable() and comedi_pci_disable() cannot be nested. + * + * Returns: + * 0 on success, + * -%ENODEV if @dev->hw_dev is %NULL, + * -%EBUSY if regions busy, + * or some negative error number if failed to enable PCI device. + * */ int comedi_pci_enable(struct comedi_device *dev) { @@ -58,8 +78,13 @@ int comedi_pci_enable(struct comedi_device *dev) EXPORT_SYMBOL_GPL(comedi_pci_enable); /** - * comedi_pci_disable() - Release the regions and disable the PCI device. - * @dev: comedi_device struct + * comedi_pci_disable() - Release the regions and disable the PCI 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 pci_dev. If the earlier call + * to comedi_pci_enable() was successful, release the PCI device's regions + * and disable it. Reset @dev->ioenabled back to %false. */ void comedi_pci_disable(struct comedi_device *dev) { @@ -74,8 +99,18 @@ void comedi_pci_disable(struct comedi_device *dev) EXPORT_SYMBOL_GPL(comedi_pci_disable); /** - * comedi_pci_detach() - A generic (*detach) function for PCI drivers. - * @dev: comedi_device struct + * comedi_pci_detach() - A generic "detach" handler for PCI COMEDI drivers + * @dev: COMEDI device. + * + * COMEDI drivers for PCI devices that need no special clean-up of private data + * and have no ioremapped regions other than that pointed to by @dev->mmio may + * use this function as its "detach" handler called by the COMEDI core when a + * COMEDI device is being detached from the low-level driver. It may be also + * called from a more specific "detach" handler that does additional clean-up. + * + * Free the IRQ if @dev->irq is non-zero, iounmap @dev->mmio if it is + * non-%NULL, and call comedi_pci_disable() to release the PCI device's regions + * and disable it. */ void comedi_pci_detach(struct comedi_device *dev) { @@ -97,12 +132,19 @@ void comedi_pci_detach(struct comedi_device *dev) EXPORT_SYMBOL_GPL(comedi_pci_detach); /** - * comedi_pci_auto_config() - Configure/probe a comedi PCI driver. - * @pcidev: pci_dev struct - * @driver: comedi_driver struct - * @context: driver specific data, passed to comedi_auto_config() + * comedi_pci_auto_config() - Configure/probe a PCI COMEDI device + * @pcidev: PCI device. + * @driver: Registered COMEDI driver. + * @context: Driver specific data, passed to comedi_auto_config(). * - * Typically called from the pci_driver (*probe) function. + * Typically called from the pci_driver (*probe) function. Auto-configure + * a COMEDI device, using the &struct device embedded in *@pcidev as the + * hardware device. The @context value gets passed through to @driver's + * "auto_attach" handler. The "auto_attach" handler may call + * comedi_to_pci_dev() on the passed in COMEDI device to recover @pcidev. + * + * Returns: The result of calling comedi_auto_config() (0 on success, or + * a negative error number on failure). */ int comedi_pci_auto_config(struct pci_dev *pcidev, struct comedi_driver *driver, @@ -113,10 +155,18 @@ int comedi_pci_auto_config(struct pci_dev *pcidev, EXPORT_SYMBOL_GPL(comedi_pci_auto_config); /** - * comedi_pci_auto_unconfig() - Unconfigure/remove a comedi PCI driver. - * @pcidev: pci_dev struct + * comedi_pci_auto_unconfig() - Unconfigure/remove a PCI COMEDI device + * @pcidev: PCI device. + * + * Typically called from the pci_driver (*remove) function. Auto-unconfigure + * a COMEDI device attached to this PCI device, using a pointer to the + * &struct device embedded in *@pcidev as the hardware device. The COMEDI + * driver's "detach" handler will be called during unconfiguration of the + * COMEDI device. * - * Typically called from the pci_driver (*remove) function. + * 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_pci_auto_unconfig(struct pci_dev *pcidev) { @@ -125,13 +175,15 @@ void comedi_pci_auto_unconfig(struct pci_dev *pcidev) EXPORT_SYMBOL_GPL(comedi_pci_auto_unconfig); /** - * comedi_pci_driver_register() - Register a comedi PCI driver. - * @comedi_driver: comedi_driver struct - * @pci_driver: pci_driver struct + * comedi_pci_driver_register() - Register a PCI COMEDI driver + * @comedi_driver: COMEDI driver to be registered. + * @pci_driver: PCI driver to be registered. + * + * This function is called from the module_init() of PCI COMEDI driver modules + * to register the COMEDI driver and the PCI driver. Do not call it directly, + * use the module_comedi_pci_driver() helper macro instead. * - * This function is used for the module_init() of comedi PCI drivers. - * Do not call it directly, use the module_comedi_pci_driver() helper - * macro instead. + * Returns: 0 on success, or a negative error number on failure. */ int comedi_pci_driver_register(struct comedi_driver *comedi_driver, struct pci_driver *pci_driver) @@ -153,13 +205,13 @@ int comedi_pci_driver_register(struct comedi_driver *comedi_driver, EXPORT_SYMBOL_GPL(comedi_pci_driver_register); /** - * comedi_pci_driver_unregister() - Unregister a comedi PCI driver. - * @comedi_driver: comedi_driver struct - * @pci_driver: pci_driver struct + * comedi_pci_driver_unregister() - Unregister a PCI COMEDI driver + * @comedi_driver: COMEDI driver to be unregistered. + * @pci_driver: PCI driver to be unregistered. * - * This function is used for the module_exit() of comedi PCI drivers. - * Do not call it directly, use the module_comedi_pci_driver() helper - * macro instead. + * This function is called from the module_exit() of PCI COMEDI driver modules + * to unregister the PCI driver and the COMEDI driver. Do not call it + * directly, use the module_comedi_pci_driver() helper macro instead. */ void comedi_pci_driver_unregister(struct comedi_driver *comedi_driver, struct pci_driver *pci_driver) -- 2.30.2