staging: comedi: drivers.c: document exported functions

/* protects access to comedi_drivers */

DEFINE_MUTEX(comedi_drivers_list_lock);

/**

 * comedi_set_hw_dev() - Set hardware device associated with COMEDI device

 * @dev: COMEDI device.

 * @hw_dev: Hardware device.

 *

 * For automatically configured COMEDI devices (resulting from a call to

 * comedi_auto_config() or one of its wrappers from the low-level COMEDI

 * driver), comedi_set_hw_dev() is called automatically by the COMEDI core

 * to associate the COMEDI device with the hardware device.  It can also be

 * called directly by "legacy" low-level COMEDI drivers that rely on the

 * %COMEDI_DEVCONFIG ioctl to configure the hardware as long as the hardware

 * has a &struct device.

 *

 * If @dev->hw_dev is NULL, it gets a reference to @hw_dev and sets

 * @dev->hw_dev, otherwise, it does nothing.  Calling it multiple times

 * with the same hardware device is not considered an error.  If it gets

 * a reference to the hardware device, it will be automatically 'put' when

 * the device is detached from COMEDI.

 *

 * Returns 0 if @dev->hw_dev was NULL or the same as @hw_dev, otherwise

 * returns -EEXIST.

 */

int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev)

{

	if (hw_dev == dev->hw_dev)

}

/**

 * comedi_alloc_devpriv() - Allocate memory for the device private data.

 * @dev: comedi_device struct

 * @size: size of the memory to allocate

 * comedi_alloc_devpriv() - Allocate memory for the device private data

 * @dev: COMEDI device.

 * @size: Size of the memory to allocate.

 *

 * The allocated memory is zero-filled.  @dev->private points to it on

 * return.  The memory will be automatically freed when the COMEDI device is

 * "detached".

 *

 * Returns a pointer to the allocated memory, or NULL on failure.

 */

void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size)

{

}

EXPORT_SYMBOL_GPL(comedi_alloc_devpriv);

/**

 * comedi_alloc_subdevices() - Allocate subdevices for COMEDI device

 * @dev: COMEDI device.

 * @num_subdevices: Number of subdevices to allocate.

 *

 * Allocates and initializes an array of &struct comedi_subdevice for the

 * COMEDI device.  If successful, sets @dev->subdevices to point to the

 * first one and @dev->n_subdevices to the number.

 *

 * Returns 0 on success, -EINVAL if @num_subdevices is < 1, or -ENOMEM if

 * failed to allocate the memory.

 */

int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)

{

	struct comedi_subdevice *s;

EXPORT_SYMBOL_GPL(comedi_alloc_subdevices);

/**

 * comedi_alloc_subdev_readback() - Allocate memory for the subdevice readback.

 * @s: comedi_subdevice struct

 * comedi_alloc_subdev_readback() - Allocate memory for the subdevice readback

 * @s: COMEDI subdevice.

 *

 * This is called by low-level COMEDI drivers to allocate an array to record

 * the last values written to a subdevice's analog output channels (at least

 * by the %INSN_WRITE instruction), to allow them to be read back by an

 * %INSN_READ instruction.  It also provides a default handler for the

 * %INSN_READ instruction unless one has already been set.

 *

 * On success, @s->readback points to the first element of the array, which

 * is zero-filled.  The low-level driver is responsible for updating its

 * contents.  @s->insn_read will be set to comedi_readback_insn_read()

 * unless it is already non-NULL.

 *

 * Returns 0 on success, -EINVAL if the subdevice has no channels, or

 * -ENOMEM on allocation failure.

 */

int comedi_alloc_subdev_readback(struct comedi_subdevice *s)

{

/**

 * comedi_readback_insn_read() - A generic (*insn_read) for subdevice readback.

 * @dev: comedi_device struct

 * @s: comedi_subdevice struct

 * @insn: comedi_insn struct

 * @data: pointer to return the readback data

 * @dev: COMEDI device.

 * @s: COMEDI subdevice.

 * @insn: COMEDI instruction.

 * @data: Pointer to return the readback data.

 *

 * Handles the %INSN_READ instruction for subdevices that use the readback

 * array allocated by comedi_alloc_subdev_readback().  It may be used

 * directly as the subdevice's handler (@s->insn_read) or called via a

 * wrapper.

 *

 * @insn->n is normally 1, which will read a single value.  If higher, the

 * same element of the readback array will be read multiple times.

 *

 * Returns @insn->n on success, or -EINVAL if @s->readback is NULL.

 */

int comedi_readback_insn_read(struct comedi_device *dev,

			      struct comedi_subdevice *s,

EXPORT_SYMBOL_GPL(comedi_readback_insn_read);

/**

 * comedi_timeout() - busy-wait for a driver condition to occur.

 * @dev: comedi_device struct

 * @s: comedi_subdevice struct

 * @insn: comedi_insn struct

 * @cb: callback to check for the condition

 * @context: private context from the driver

 * comedi_timeout() - Busy-wait for a driver condition to occur

 * @dev: COMEDI device.

 * @s: COMEDI subdevice.

 * @insn: COMEDI instruction.

 * @cb: Callback to check for the condition.

 * @context: Private context from the driver.

 *

 * Busy-waits for up to a second (%COMEDI_TIMEOUT_MS) for the condition or

 * some error (other than -EBUSY) to occur.  The parameters @dev, @s, @insn,

 * and @context are passed to the callback function, which returns -EBUSY to

 * continue waiting or some other value to stop waiting (generally 0 if the

 * condition occurred, or some error value).

 *

 * Returns -ETIMEDOUT if timed out, otherwise the return value from the

 * callback function.

 */

int comedi_timeout(struct comedi_device *dev,

		   struct comedi_subdevice *s,

EXPORT_SYMBOL_GPL(comedi_timeout);

/**

 * comedi_dio_insn_config() - boilerplate (*insn_config) for DIO subdevices.

 * @dev: comedi_device struct

 * @s: comedi_subdevice struct

 * @insn: comedi_insn struct

 * @data: parameters for the @insn

 * @mask: io_bits mask for grouped channels

 * comedi_dio_insn_config() - Boilerplate (*insn_config) for DIO subdevices

 * @dev: COMEDI device.

 * @s: COMEDI subdevice.

 * @insn: COMEDI instruction.

 * @data: Instruction parameters and return data.

 * @mask: io_bits mask for grouped channels, or 0 for single channel.

 *

 * If @mask is 0, it is replaced with a single-bit mask corresponding to the

 * channel number specified by @insn->chanspec.  Otherwise, @mask

 * corresponds to a group of channels (which should include the specified

 * channel) that are always configured together as inputs or outputs.

 *

 * Partially handles the %INSN_CONFIG_DIO_INPUT, %INSN_CONFIG_DIO_OUTPUTS,

 * and %INSN_CONFIG_DIO_QUERY instructions.  The first two update

 * @s->io_bits to record the directions of the masked channels.  The last

 * one sets @data[1] to the current direction of the group of channels

 * (%COMEDI_INPUT) or %COMEDI_OUTPUT) as recorded in @s->io_bits.

 *

 * The caller is responsible for updating the DIO direction in the hardware

 * registers if this function returns 0.

 *

 * Returns 0 for a %INSN_CONFIG_DIO_INPUT or %INSN_CONFIG_DIO_OUTPUT

 * instruction, @insn->n (> 0) for a %INSN_CONFIG_DIO_QUERY instruction, or

 * -EINVAL for some other instruction.

 */

int comedi_dio_insn_config(struct comedi_device *dev,

			   struct comedi_subdevice *s,

EXPORT_SYMBOL_GPL(comedi_dio_insn_config);

/**

 * comedi_dio_update_state() - update the internal state of DIO subdevices.

 * @s: comedi_subdevice struct

 * @data: the channel mask and bits to update

 * comedi_dio_update_state() - Update the internal state of DIO subdevices

 * @s: COMEDI subdevice.

 * @data: The channel mask and bits to update.

 *

 * Updates @s->state which holds the internal state of the outputs for DIO

 * or DO subdevices (up to 32 channels).  @data[0] contains a bit-mask of

 * the channels to be updated.  @data[1] contains a bit-mask of those

 * channels to be set to '1'.  The caller is responsible for updating the

 * outputs in hardware according to @s->state.  As a minimum, the channels

 * in the returned bit-mask need to be updated.

 *

 * Returns @mask with non-existent channels removed.

 */

unsigned int comedi_dio_update_state(struct comedi_subdevice *s,

				     unsigned int *data)

EXPORT_SYMBOL_GPL(comedi_dio_update_state);

/**

 * comedi_bytes_per_scan - get length of asynchronous command "scan" in bytes

 * @s: comedi_subdevice struct

 * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes

 * @s: COMEDI subdevice.

 *

 * Determines the overall scan length according to the subdevice type and the

 * number of channels in the scan.

 *

 * For digital input, output or input/output subdevices, samples for multiple

 * channels are assumed to be packed into one or more unsigned short or

 * unsigned int values according to the subdevice's SDF_LSAMPL flag.  For other

 * types of subdevice, samples are assumed to occupy a whole unsigned short or

 * unsigned int according to the SDF_LSAMPL flag.

 * For digital input, output or input/output subdevices, samples for

 * multiple channels are assumed to be packed into one or more unsigned

 * short or unsigned int values according to the subdevice's %SDF_LSAMPL

 * flag.  For other types of subdevice, samples are assumed to occupy a

 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag.

 *

 * Returns the overall scan length in bytes.

 */

EXPORT_SYMBOL_GPL(comedi_bytes_per_scan);

/**

 * comedi_nscans_left - return the number of scans left in the command

 * @s: comedi_subdevice struct

 * @nscans: the expected number of scans

 * comedi_nscans_left() - Return the number of scans left in the command

 * @s: COMEDI subdevice.

 * @nscans: The expected number of scans or 0 for all available scans.

 *

 * If nscans is 0, the number of scans available in the async buffer will be

 * used. Otherwise the expected number of scans will be used.

 * If @nscans is 0, it is set to the number of scans available in the

 * async buffer.

 *

 * If the async command has a stop_src of TRIG_COUNT, the nscans will be

 * checked against the number of scans left in the command.

 * If the async command has a stop_src of %TRIG_COUNT, the @nscans will be

 * checked against the number of scans remaining to complete the command.

 *

 * The return value will then be either the expected number of scans or the

 * number of scans remaining in the command.

 * number of scans remaining to complete the command, whichever is fewer.

 */

unsigned int comedi_nscans_left(struct comedi_subdevice *s,

				unsigned int nscans)

EXPORT_SYMBOL_GPL(comedi_nscans_left);

/**

 * comedi_nsamples_left - return the number of samples left in the command

 * @s: comedi_subdevice struct

 * @nsamples: the expected number of samples

 * comedi_nsamples_left() - Return the number of samples left in the command

 * @s: COMEDI subdevice.

 * @nsamples: The expected number of samples.

 *

 * Returns the expected number of samples of the number of samples remaining

 * in the command.

 * Returns the number of samples remaining to complete the command, or the

 * specified expected number of samples (@nsamples), whichever is fewer.

 */

unsigned int comedi_nsamples_left(struct comedi_subdevice *s,

				  unsigned int nsamples)

EXPORT_SYMBOL_GPL(comedi_nsamples_left);

/**

 * comedi_inc_scan_progress - update scan progress in asynchronous command

 * @s: comedi_subdevice struct

 * @num_bytes: amount of data in bytes to increment scan progress

 * comedi_inc_scan_progress() - Update scan progress in asynchronous command

 * @s: COMEDI subdevice.

 * @num_bytes: Amount of data in bytes to increment scan progress.

 *

 * Increments the scan progress by the number of bytes specified by num_bytes.

 * Increments the scan progress by the number of bytes specified by @num_bytes.

 * If the scan progress reaches or exceeds the scan length in bytes, reduce

 * it modulo the scan length in bytes and set the "end of scan" asynchronous

 * event flag to be processed later.

 * event flag (%COMEDI_CB_EOS) to be processed later.

 */

void comedi_inc_scan_progress(struct comedi_subdevice *s,

			      unsigned int num_bytes)

EXPORT_SYMBOL_GPL(comedi_inc_scan_progress);

/**

 * comedi_handle_events - handle events and possibly stop acquisition

 * @dev: comedi_device struct

 * @s: comedi_subdevice struct

 * comedi_handle_events() - Handle events and possibly stop acquisition

 * @dev: COMEDI device.

 * @s: COMEDI subdevice.

 *

 * Handles outstanding asynchronous acquisition event flags associated

 * with the subdevice.  Call the subdevice's "->cancel()" handler if the

 * with the subdevice.  Call the subdevice's @s->cancel() handler if the

 * "end of acquisition", "error" or "overflow" event flags are set in order

 * to stop the acquisition at the driver level.

 *

}

/**

 * comedi_load_firmware() - Request and load firmware for a device.

 * @dev: comedi_device struct

 * @hw_device: device struct for the comedi_device

 * @name: the name of the firmware image

 * @cb: callback to the upload the firmware image

 * @context: private context from the driver

 * comedi_load_firmware() - Request and load firmware for a device

 * @dev: COMEDI device.

 * @device: Hardware device.

 * @name: The name of the firmware image.

 * @cb: Callback to the upload the firmware image.

 * @context: Private context from the driver.

 *

 * Sends a firmware request for the hardware device and waits for it.  Calls

 * the callback function to upload the firmware to the device, them releases

 * the firmware.

 *

 * Returns 0 on success, -EINVAL if @cb is NULL, or a negative error number

 * from the firmware request or the callback function.

 */

int comedi_load_firmware(struct comedi_device *dev,

			 struct device *device,

EXPORT_SYMBOL_GPL(comedi_load_firmware);

/**

 * __comedi_request_region() - Request an I/O reqion for a legacy driver.

 * @dev: comedi_device struct

 * @start: base address of the I/O reqion

 * @len: length of the I/O region

 * __comedi_request_region() - Request an I/O region for a legacy driver

 * @dev: COMEDI device.

 * @start: Base address of the I/O region.

 * @len: Length of the I/O region.

 *

 * Requests the specified I/O port region which must start at a non-zero

 * address.

 *

 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request

 * fails.

 */

int __comedi_request_region(struct comedi_device *dev,

			    unsigned long start, unsigned long len)

EXPORT_SYMBOL_GPL(__comedi_request_region);

/**

 * comedi_request_region() - Request an I/O reqion for a legacy driver.

 * @dev: comedi_device struct

 * @start: base address of the I/O reqion

 * @len: length of the I/O region

 * comedi_request_region() - Request an I/O region for a legacy driver

 * @dev: COMEDI device.

 * @start: Base address of the I/O region.

 * @len: Length of the I/O region.

 *

 * Requests the specified I/O port region which must start at a non-zero

 * address.

 *

 * On success, @dev->iobase is set to the base address of the region and

 * @dev->iolen is set to its length.

 *

 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request

 * fails.

 */

int comedi_request_region(struct comedi_device *dev,

			  unsigned long start, unsigned long len)

EXPORT_SYMBOL_GPL(comedi_request_region);

/**

 * comedi_legacy_detach() - A generic (*detach) function for legacy drivers.

 * @dev: comedi_device struct

 * comedi_legacy_detach() - A generic (*detach) function for legacy drivers

 * @dev: COMEDI device.

 *

 * This is a simple, generic 'detach' handler for legacy COMEDI devices that

 * just use a single I/O port region and possibly an IRQ and that don't need

 * any special clean-up for their private device or subdevice storage.  It

 * can also be called by a driver-specific 'detach' handler.

 *

 * If @dev->irq is non-zero, the IRQ will be freed.  If @dev->iobase and

 * @dev->iolen are both non-zero, the I/O port region will be released.

 */

void comedi_legacy_detach(struct comedi_device *dev)

{

	return ret;

}

/**

 * comedi_auto_config() - Create a COMEDI device for a hardware device

 * @hardware_device: Hardware device.

 * @driver: COMEDI low-level driver for the hardware device.

 * @context: Driver context for the auto_attach handler.

 *

 * Allocates a new COMEDI device for the hardware device and calls the

 * low-level driver's 'auto_attach' handler to set-up the hardware and

 * allocate the COMEDI subdevices.  Additional "post-configuration" setting

 * up is performed on successful return from the 'auto_attach' handler.

 * If the 'auto_attach' handler fails, the low-level driver's 'detach'

 * handler will be called as part of the clean-up.

 *

 * This is usually called from a wrapper function in a bus-specific COMEDI

 * module, which in turn is usually called from a bus device 'probe'

 * function in the low-level driver.

 *

 * Returns 0 on success, -EINVAL if the parameters are invalid or the

 * post-configuration determines the driver has set the COMEDI device up

 * incorrectly, -ENOMEM if failed to allocate memory, -EBUSY if run out of

 * COMEDI minor device numbers, or some negative error number returned by

 * the driver's 'auto_attach' handler.

 */

int comedi_auto_config(struct device *hardware_device,

		       struct comedi_driver *driver, unsigned long context)

{

}

EXPORT_SYMBOL_GPL(comedi_auto_config);

/**

 * comedi_auto_unconfig() - Unconfigure auto-allocated COMEDI device

 * @hardware_device: Hardware device previously passed to

 *                   comedi_auto_config().

 *

 * Cleans up and eventually destroys the COMEDI device allocated by

 * comedi_auto_config() for the same hardware device.  As part of this

 * clean-up, the low-level COMEDI driver's 'detach' handler will be called.

 * (The COMEDI device itself will persist in an unattached state if it is

 * still open, until it is released, and any mmapped buffers will persist

 * until they are munmapped.)

 *

 * This is usually called from a wrapper module in a bus-specific COMEDI

 * module, which in turn is usually set as the bus device 'remove' function

 * in the low-level COMEDI driver.

 */

void comedi_auto_unconfig(struct device *hardware_device)

{

	if (!hardware_device)

}

EXPORT_SYMBOL_GPL(comedi_auto_unconfig);

/**

 * comedi_driver_register() - Register a low-level COMEDI driver

 * @driver: Low-level COMEDI driver.

 *

 * The low-level COMEDI driver is added to the list of registered COMEDI

 * drivers.  This is used by the handler for the "/proc/comedi" file and is

 * also used by the handler for the %COMEDI_DEVCONFIG ioctl to configure

 * "legacy" COMEDI devices (for those low-level drivers that support it).

 *

 * Returns 0.

 */

int comedi_driver_register(struct comedi_driver *driver)

{

	mutex_lock(&comedi_drivers_list_lock);

}

EXPORT_SYMBOL_GPL(comedi_driver_register);

/**

 * comedi_driver_unregister() - Unregister a low-level COMEDI driver

 * @driver: Low-level COMEDI driver.

 *

 * The low-level COMEDI driver is removed from the list of registered COMEDI

 * drivers.  Detaches any COMEDI devices attached to the driver, which will

 * result in the low-level driver's 'detach' handler being called for those

 * devices before this function returns.

 */

void comedi_driver_unregister(struct comedi_driver *driver)

{

	struct comedi_driver *prev;