Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3479610c authored by Ian Abbott's avatar Ian Abbott Committed by Greg Kroah-Hartman
Browse files

staging: comedi: 8255.c: document subdev_8255_init() and _mm_init() 



Add kerneldoc comments for the subdev_8255_init() and
subdev_8255_mm_init() functions and remove the other comment about how
to use this module in a comedi driver.

Signed-off-by: default avatarIan Abbott <abbotti@mev.co.uk>
Reviewed-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 20f2ff88

drivers/staging/comedi/drivers/8255.c

+54 −25
Original line number Diff line number Diff line
@@ -48,31 +48,6 @@ 
 * I/O port base address can be found in the output of 'lspci -v'.

 */



/*

   This file contains an exported subdevice for driving an 8255.



   To use this subdevice as part of another driver, you need to

   set up the subdevice in the attach function of the driver by

   calling:



     subdev_8255_init(device, subdevice, io_function, iobase)



   device and subdevice are pointers to the device and subdevice

   structures.  io_function will be called to provide the

   low-level input/output to the device, i.e., actual register

   access.  io_function will be called with the value of iobase

   as the last parameter.  If the 8255 device is mapped as 4

   consecutive I/O ports, you can use NULL for io_function

   and the I/O port base for iobase, and an internal function will

   handle the register access.



   In addition, if the main driver handles interrupts, you can

   enable commands on the subdevice by calling subdev_8255_init_irq()

   instead.  Then, when you get an interrupt that is likely to be

   from the 8255, you should call subdev_8255_interrupt(), which

   will copy the latched value to a Comedi buffer.

 */



#include <linux/module.h>

#include "../comedidev.h"
@@ -218,6 +193,33 @@ static int __subdev_8255_init(struct comedi_device *dev, 
	return 0;

}



/**

 * subdev_8255_init - initialize DIO subdevice for driving I/O mapped 8255

 * @dev: comedi device owning subdevice

 * @s: comedi subdevice to initialize

 * @io: (optional) register I/O call-back function

 * @regbase: offset of 8255 registers from dev->iobase, or call-back context

 *

 * Initializes a comedi subdevice as a DIO subdevice driving an 8255 chip.

 *

 * If the optional I/O call-back function is provided, its prototype is of

 * the following form:

 *

 *   int my_8255_callback(struct comedi_device *dev,

 *                        struct comedi_subdevice *s, int dir, int port,

 *                        int data, unsigned long regbase);

 *

 * where 'dev', 's', and 'regbase' match the values passed to this function,

 * 'port' is the 8255 port number 0 to 3 (including the control port), 'dir'

 * is the direction (0 for read, 1 for write) and 'data' is the value to be

 * written.  It should return 0 if writing or the value read if reading.

 *

 * If the optional I/O call-back function is not provided, an internal

 * call-back function is used which uses consecutive I/O port addresses

 * starting at dev->iobase + regbase.

 *

 * Return: -ENOMEM if failed to allocate memory, zero on success.

 */

int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,

		     int (*io)(struct comedi_device *,

			       int, int, int, unsigned long),
@@ -227,6 +229,33 @@ int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s, 
}

EXPORT_SYMBOL_GPL(subdev_8255_init);



/**

 * subdev_8255_mm_init - initialize DIO subdevice for driving mmio-mapped 8255

 * @dev: comedi device owning subdevice

 * @s: comedi subdevice to initialize

 * @io: (optional) register I/O call-back function

 * @regbase: offset of 8255 registers from dev->mmio, or call-back context

 *

 * Initializes a comedi subdevice as a DIO subdevice driving an 8255 chip.

 *

 * If the optional I/O call-back function is provided, its prototype is of

 * the following form:

 *

 *   int my_8255_callback(struct comedi_device *dev,

 *                        struct comedi_subdevice *s, int dir, int port,

 *                        int data, unsigned long regbase);

 *

 * where 'dev', 's', and 'regbase' match the values passed to this function,

 * 'port' is the 8255 port number 0 to 3 (including the control port), 'dir'

 * is the direction (0 for read, 1 for write) and 'data' is the value to be

 * written.  It should return 0 if writing or the value read if reading.

 *

 * If the optional I/O call-back function is not provided, an internal

 * call-back function is used which uses consecutive MMIO virtual addresses

 * starting at dev->mmio + regbase.

 *

 * Return: -ENOMEM if failed to allocate memory, zero on success.

 */

int subdev_8255_mm_init(struct comedi_device *dev, struct comedi_subdevice *s,

			int (*io)(struct comedi_device *,

				  int, int, int, unsigned long),