OSCL-LXR linux-6.0.1/​include/​linux/​comedi/​comedidev.h	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * comedidev.h
  * header file for kernel-only structures, variables, and constants
  *
  * COMEDI - Linux Control and Measurement Device Interface
  * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
  */
 
 #ifndef _COMEDIDEV_H
 #define _COMEDIDEV_H
 
 #include <linux/dma-mapping.h>
 #include <linux/mutex.h>
 #include <linux/spinlock_types.h>
 #include <linux/rwsem.h>
 #include <linux/kref.h>
 #include <linux/comedi.h>
 
 #define COMEDI_VERSION(a, b, c) (((a) << 16) + ((b) << 8) + (c))
 #define COMEDI_VERSION_CODE COMEDI_VERSION(COMEDI_MAJORVERSION, \
     COMEDI_MINORVERSION, COMEDI_MICROVERSION)
 #define COMEDI_RELEASE VERSION
 
 #define COMEDI_NUM_BOARD_MINORS 0x30
 
 /**
  * struct comedi_subdevice - Working data for a COMEDI subdevice
  * @device: COMEDI device to which this subdevice belongs.  (Initialized by
  *  comedi_alloc_subdevices().)
  * @index: Index of this subdevice within device's array of subdevices.
  *  (Initialized by comedi_alloc_subdevices().)
  * @type: Type of subdevice from &enum comedi_subdevice_type.  (Initialized by
  *  the low-level driver.)
  * @n_chan: Number of channels the subdevice supports.  (Initialized by the
  *  low-level driver.)
  * @subdev_flags: Various "SDF" flags indicating aspects of the subdevice to
  *  the COMEDI core and user application.  (Initialized by the low-level
  *  driver.)
  * @len_chanlist: Maximum length of a channel list if the subdevice supports
  *  asynchronous acquisition commands.  (Optionally initialized by the
  *  low-level driver, or changed from 0 to 1 during post-configuration.)
  * @private: Private data pointer which is either set by the low-level driver
  *  itself, or by a call to comedi_alloc_spriv() which allocates storage.
  *  In the latter case, the storage is automatically freed after the
  *  low-level driver's "detach" handler is called for the device.
  *  (Initialized by the low-level driver.)
  * @async: Pointer to &struct comedi_async id the subdevice supports
  *  asynchronous acquisition commands.  (Allocated and initialized during
  *  post-configuration if needed.)
  * @lock: Pointer to a file object that performed a %COMEDI_LOCK ioctl on the
  *  subdevice.  (Initially NULL.)
  * @busy: Pointer to a file object that is performing an asynchronous
  *  acquisition command on the subdevice.  (Initially NULL.)
  * @runflags: Internal flags for use by COMEDI core, mostly indicating whether
  *  an asynchronous acquisition command is running.
  * @spin_lock: Generic spin-lock for use by the COMEDI core and the low-level
  *  driver.  (Initialized by comedi_alloc_subdevices().)
  * @io_bits: Bit-mask indicating the channel directions for a DIO subdevice
  *  with no more than 32 channels.  A '1' at a bit position indicates the
  *  corresponding channel is configured as an output.  (Initialized by the
  *  low-level driver for a DIO subdevice.  Forced to all-outputs during
  *  post-configuration for a digital output subdevice.)
  * @maxdata: If non-zero, this is the maximum raw data value of each channel.
  *  If zero, the maximum data value is channel-specific.  (Initialized by
  *  the low-level driver.)
  * @maxdata_list: If the maximum data value is channel-specific, this points
  *  to an array of maximum data values indexed by channel index.
  *  (Initialized by the low-level driver.)
  * @range_table: If non-NULL, this points to a COMEDI range table for the
  *  subdevice.  If NULL, the range table is channel-specific.  (Initialized
  *  by the low-level driver, will be set to an "invalid" range table during
  *  post-configuration if @range_table and @range_table_list are both
  *  NULL.)
  * @range_table_list: If the COMEDI range table is channel-specific, this
  *  points to an array of pointers to COMEDI range tables indexed by
  *  channel number.  (Initialized by the low-level driver.)
  * @chanlist: Not used.
  * @insn_read: Optional pointer to a handler for the %INSN_READ instruction.
  *  (Initialized by the low-level driver, or set to a default handler
  *  during post-configuration.)
  * @insn_write: Optional pointer to a handler for the %INSN_WRITE instruction.
  *  (Initialized by the low-level driver, or set to a default handler
  *  during post-configuration.)
  * @insn_bits: Optional pointer to a handler for the %INSN_BITS instruction
  *  for a digital input, digital output or digital input/output subdevice.
  *  (Initialized by the low-level driver, or set to a default handler
  *  during post-configuration.)
  * @insn_config: Optional pointer to a handler for the %INSN_CONFIG
  *  instruction.  (Initialized by the low-level driver, or set to a default
  *  handler during post-configuration.)
  * @do_cmd: If the subdevice supports asynchronous acquisition commands, this
  *  points to a handler to set it up in hardware.  (Initialized by the
  *  low-level driver.)
  * @do_cmdtest: If the subdevice supports asynchronous acquisition commands,
  *  this points to a handler used to check and possibly tweak a prospective
  *  acquisition command without setting it up in hardware.  (Initialized by
  *  the low-level driver.)
  * @poll: If the subdevice supports asynchronous acquisition commands, this
  *  is an optional pointer to a handler for the %COMEDI_POLL ioctl which
  *  instructs the low-level driver to synchronize buffers.  (Initialized by
  *  the low-level driver if needed.)
  * @cancel: If the subdevice supports asynchronous acquisition commands, this
  *  points to a handler used to terminate a running command.  (Initialized
  *  by the low-level driver.)
  * @buf_change: If the subdevice supports asynchronous acquisition commands,
  *  this is an optional pointer to a handler that is called when the data
  *  buffer for handling asynchronous commands is allocated or reallocated.
  *  (Initialized by the low-level driver if needed.)
  * @munge: If the subdevice supports asynchronous acquisition commands and
  *  uses DMA to transfer data from the hardware to the acquisition buffer,
  *  this points to a function used to "munge" the data values from the
  *  hardware into the format expected by COMEDI.  (Initialized by the
  *  low-level driver if needed.)
  * @async_dma_dir: If the subdevice supports asynchronous acquisition commands
  *  and uses DMA to transfer data from the hardware to the acquisition
  *  buffer, this sets the DMA direction for the buffer. (initialized to
  *  %DMA_NONE by comedi_alloc_subdevices() and changed by the low-level
  *  driver if necessary.)
  * @state: Handy bit-mask indicating the output states for a DIO or digital
  *  output subdevice with no more than 32 channels. (Initialized by the
  *  low-level driver.)
  * @class_dev: If the subdevice supports asynchronous acquisition commands,
  *  this points to a sysfs comediX_subdY device where X is the minor device
  *  number of the COMEDI device and Y is the subdevice number.  The minor
  *  device number for the sysfs device is allocated dynamically in the
  *  range 48 to 255.  This is used to allow the COMEDI device to be opened
  *  with a different default read or write subdevice.  (Allocated during
  *  post-configuration if needed.)
  * @minor: If @class_dev is set, this is its dynamically allocated minor
  *  device number.  (Set during post-configuration if necessary.)
  * @readback: Optional pointer to memory allocated by
  *  comedi_alloc_subdev_readback() used to hold the values written to
  *  analog output channels so they can be read back.  The storage is
  *  automatically freed after the low-level driver's "detach" handler is
  *  called for the device.  (Initialized by the low-level driver.)
  *
  * This is the main control structure for a COMEDI subdevice.  If the subdevice
  * supports asynchronous acquisition commands, additional information is stored
  * in the &struct comedi_async pointed to by @async.
  *
  * Most of the subdevice is initialized by the low-level driver's "attach" or
  * "auto_attach" handlers but parts of it are initialized by
  * comedi_alloc_subdevices(), and other parts are initialized during
  * post-configuration on return from that handler.
  *
  * A low-level driver that sets @insn_bits for a digital input, digital output,
  * or DIO subdevice may leave @insn_read and @insn_write uninitialized, in
  * which case they will be set to a default handler during post-configuration
  * that uses @insn_bits to emulate the %INSN_READ and %INSN_WRITE instructions.
  */
 struct comedi_subdevice {
     struct comedi_device *device;
     int index;
     int type;
     int n_chan;
     int subdev_flags;
     int len_chanlist;   /* maximum length of channel/gain list */
 
     void *private;
 
     struct comedi_async *async;
 
     void *lock;
     void *busy;
     unsigned int runflags;
     spinlock_t spin_lock;   /* generic spin-lock for COMEDI and drivers */
 
     unsigned int io_bits;
 
     unsigned int maxdata;   /* if maxdata==0, use list */
     const unsigned int *maxdata_list;   /* list is channel specific */
 
     const struct comedi_lrange *range_table;
     const struct comedi_lrange *const *range_table_list;
 
     unsigned int *chanlist; /* driver-owned chanlist (not used) */
 
     int (*insn_read)(struct comedi_device *dev, struct comedi_subdevice *s,
              struct comedi_insn *insn, unsigned int *data);
     int (*insn_write)(struct comedi_device *dev, struct comedi_subdevice *s,
               struct comedi_insn *insn, unsigned int *data);
     int (*insn_bits)(struct comedi_device *dev, struct comedi_subdevice *s,
              struct comedi_insn *insn, unsigned int *data);
     int (*insn_config)(struct comedi_device *dev,
                struct comedi_subdevice *s,
                struct comedi_insn *insn,
                unsigned int *data);
 
     int (*do_cmd)(struct comedi_device *dev, struct comedi_subdevice *s);
     int (*do_cmdtest)(struct comedi_device *dev,
               struct comedi_subdevice *s,
               struct comedi_cmd *cmd);
     int (*poll)(struct comedi_device *dev, struct comedi_subdevice *s);
     int (*cancel)(struct comedi_device *dev, struct comedi_subdevice *s);
 
     /* called when the buffer changes */
     int (*buf_change)(struct comedi_device *dev,
               struct comedi_subdevice *s);
 
     void (*munge)(struct comedi_device *dev, struct comedi_subdevice *s,
               void *data, unsigned int num_bytes,
               unsigned int start_chan_index);
     enum dma_data_direction async_dma_dir;
 
     unsigned int state;
 
     struct device *class_dev;
     int minor;
 
     unsigned int *readback;
 };
 
 /**
  * struct comedi_buf_page - Describe a page of a COMEDI buffer
  * @virt_addr: Kernel address of page.
  * @dma_addr: DMA address of page if in DMA coherent memory.
  */
 struct comedi_buf_page {
     void *virt_addr;
     dma_addr_t dma_addr;
 };
 
 /**
  * struct comedi_buf_map - Describe pages in a COMEDI buffer
  * @dma_hw_dev: Low-level hardware &struct device pointer copied from the
  *  COMEDI device's hw_dev member.
  * @page_list: Pointer to array of &struct comedi_buf_page, one for each
  *  page in the buffer.
  * @n_pages: Number of pages in the buffer.
  * @dma_dir: DMA direction used to allocate pages of DMA coherent memory,
  *  or %DMA_NONE if pages allocated from regular memory.
  * @refcount: &struct kref reference counter used to free the buffer.
  *
  * A COMEDI data buffer is allocated as individual pages, either in
  * conventional memory or DMA coherent memory, depending on the attached,
  * low-level hardware device.  (The buffer pages also get mapped into the
  * kernel's contiguous virtual address space pointed to by the 'prealloc_buf'
  * member of &struct comedi_async.)
  *
  * The buffer is normally freed when the COMEDI device is detached from the
  * low-level driver (which may happen due to device removal), but if it happens
  * to be mmapped at the time, the pages cannot be freed until the buffer has
  * been munmapped.  That is what the reference counter is for.  (The virtual
  * address space pointed by 'prealloc_buf' is freed when the COMEDI device is
  * detached.)
  */
 struct comedi_buf_map {
     struct device *dma_hw_dev;
     struct comedi_buf_page *page_list;
     unsigned int n_pages;
     enum dma_data_direction dma_dir;
     struct kref refcount;
 };
 
 /**
  * struct comedi_async - Control data for asynchronous COMEDI commands
  * @prealloc_buf: Kernel virtual address of allocated acquisition buffer.
  * @prealloc_bufsz: Buffer size (in bytes).
  * @buf_map: Map of buffer pages.
  * @max_bufsize: Maximum allowed buffer size (in bytes).
  * @buf_write_count: "Write completed" count (in bytes, modulo 2**32).
  * @buf_write_alloc_count: "Allocated for writing" count (in bytes,
  *  modulo 2**32).
  * @buf_read_count: "Read completed" count (in bytes, modulo 2**32).
  * @buf_read_alloc_count: "Allocated for reading" count (in bytes,
  *  modulo 2**32).
  * @buf_write_ptr: Buffer position for writer.
  * @buf_read_ptr: Buffer position for reader.
  * @cur_chan: Current position in chanlist for scan (for those drivers that
  *  use it).
  * @scans_done: The number of scans completed.
  * @scan_progress: Amount received or sent for current scan (in bytes).
  * @munge_chan: Current position in chanlist for "munging".
  * @munge_count: "Munge" count (in bytes, modulo 2**32).
  * @munge_ptr: Buffer position for "munging".
  * @events: Bit-vector of events that have occurred.
  * @cmd: Details of comedi command in progress.
  * @wait_head: Task wait queue for file reader or writer.
  * @cb_mask: Bit-vector of events that should wake waiting tasks.
  * @inttrig: Software trigger function for command, or NULL.
  *
  * Note about the ..._count and ..._ptr members:
  *
  * Think of the _Count values being integers of unlimited size, indexing
  * into a buffer of infinite length (though only an advancing portion
  * of the buffer of fixed length prealloc_bufsz is accessible at any
  * time).  Then:
  *
  *   Buf_Read_Count <= Buf_Read_Alloc_Count <= Munge_Count <=
  *   Buf_Write_Count <= Buf_Write_Alloc_Count <=
  *   (Buf_Read_Count + prealloc_bufsz)
  *
  * (Those aren't the actual members, apart from prealloc_bufsz.) When the
  * buffer is reset, those _Count values start at 0 and only increase in value,
  * maintaining the above inequalities until the next time the buffer is
  * reset.  The buffer is divided into the following regions by the inequalities:
  *
  *   [0, Buf_Read_Count):
  *     old region no longer accessible
  *
  *   [Buf_Read_Count, Buf_Read_Alloc_Count):
  *     filled and munged region allocated for reading but not yet read
  *
  *   [Buf_Read_Alloc_Count, Munge_Count):
  *     filled and munged region not yet allocated for reading
  *
  *   [Munge_Count, Buf_Write_Count):
  *     filled region not yet munged
  *
  *   [Buf_Write_Count, Buf_Write_Alloc_Count):
  *     unfilled region allocated for writing but not yet written
  *
  *   [Buf_Write_Alloc_Count, Buf_Read_Count + prealloc_bufsz):
  *     unfilled region not yet allocated for writing
  *
  *   [Buf_Read_Count + prealloc_bufsz, infinity):
  *     unfilled region not yet accessible
  *
  * Data needs to be written into the buffer before it can be read out,
  * and may need to be converted (or "munged") between the two
  * operations.  Extra unfilled buffer space may need to allocated for
  * writing (advancing Buf_Write_Alloc_Count) before new data is written.
  * After writing new data, the newly filled space needs to be released
  * (advancing Buf_Write_Count).  This also results in the new data being
  * "munged" (advancing Munge_Count).  Before data is read out of the
  * buffer, extra space may need to be allocated for reading (advancing
  * Buf_Read_Alloc_Count).  After the data has been read out, the space
  * needs to be released (advancing Buf_Read_Count).
  *
  * The actual members, buf_read_count, buf_read_alloc_count,
  * munge_count, buf_write_count, and buf_write_alloc_count take the
  * value of the corresponding capitalized _Count values modulo 2^32
  * (UINT_MAX+1).  Subtracting a "higher" _count value from a "lower"
  * _count value gives the same answer as subtracting a "higher" _Count
  * value from a lower _Count value because prealloc_bufsz < UINT_MAX+1.
  * The modulo operation is done implicitly.
  *
  * The buf_read_ptr, munge_ptr, and buf_write_ptr members take the value
  * of the corresponding capitalized _Count values modulo prealloc_bufsz.
  * These correspond to byte indices in the physical buffer.  The modulo
  * operation is done by subtracting prealloc_bufsz when the value
  * exceeds prealloc_bufsz (assuming prealloc_bufsz plus the increment is
  * less than or equal to UINT_MAX).
  */
 struct comedi_async {
     void *prealloc_buf;
     unsigned int prealloc_bufsz;
     struct comedi_buf_map *buf_map;
     unsigned int max_bufsize;
     unsigned int buf_write_count;
     unsigned int buf_write_alloc_count;
     unsigned int buf_read_count;
     unsigned int buf_read_alloc_count;
     unsigned int buf_write_ptr;
     unsigned int buf_read_ptr;
     unsigned int cur_chan;
     unsigned int scans_done;
     unsigned int scan_progress;
     unsigned int munge_chan;
     unsigned int munge_count;
     unsigned int munge_ptr;
     unsigned int events;
     struct comedi_cmd cmd;
     wait_queue_head_t wait_head;
     unsigned int cb_mask;
     int (*inttrig)(struct comedi_device *dev, struct comedi_subdevice *s,
                unsigned int x);
 };
 
 /**
  * enum comedi_cb - &struct comedi_async callback "events"
  * @COMEDI_CB_EOS:      end-of-scan
  * @COMEDI_CB_EOA:      end-of-acquisition/output
  * @COMEDI_CB_BLOCK:        data has arrived, wakes up read() / write()
  * @COMEDI_CB_EOBUF:        DEPRECATED: end of buffer
  * @COMEDI_CB_ERROR:        card error during acquisition
  * @COMEDI_CB_OVERFLOW:     buffer overflow/underflow
  * @COMEDI_CB_ERROR_MASK:   events that indicate an error has occurred
  * @COMEDI_CB_CANCEL_MASK:  events that will cancel an async command
  */
 enum comedi_cb {
     COMEDI_CB_EOS       = BIT(0),
     COMEDI_CB_EOA       = BIT(1),
     COMEDI_CB_BLOCK     = BIT(2),
     COMEDI_CB_EOBUF     = BIT(3),
     COMEDI_CB_ERROR     = BIT(4),
     COMEDI_CB_OVERFLOW  = BIT(5),
     /* masks */
     COMEDI_CB_ERROR_MASK    = (COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW),
     COMEDI_CB_CANCEL_MASK   = (COMEDI_CB_EOA | COMEDI_CB_ERROR_MASK)
 };
 
 /**
  * struct comedi_driver - COMEDI driver registration
  * @driver_name: Name of driver.
  * @module: Owning module.
  * @attach: The optional "attach" handler for manually configured COMEDI
  *  devices.
  * @detach: The "detach" handler for deconfiguring COMEDI devices.
  * @auto_attach: The optional "auto_attach" handler for automatically
  *  configured COMEDI devices.
  * @num_names: Optional number of "board names" supported.
  * @board_name: Optional pointer to a pointer to a board name.  The pointer
  *  to a board name is embedded in an element of a driver-defined array
  *  of static, read-only board type information.
  * @offset: Optional size of each element of the driver-defined array of
  *  static, read-only board type information, i.e. the offset between each
  *  pointer to a board name.
  *
  * This is used with comedi_driver_register() and comedi_driver_unregister() to
  * register and unregister a low-level COMEDI driver with the COMEDI core.
  *
  * If @num_names is non-zero, @board_name should be non-NULL, and @offset
  * should be at least sizeof(*board_name).  These are used by the handler for
  * the %COMEDI_DEVCONFIG ioctl to match a hardware device and its driver by
  * board name.  If @num_names is zero, the %COMEDI_DEVCONFIG ioctl matches a
  * hardware device and its driver by driver name.  This is only useful if the
  * @attach handler is set.  If @num_names is non-zero, the driver's @attach
  * handler will be called with the COMEDI device structure's board_ptr member
  * pointing to the matched pointer to a board name within the driver's private
  * array of static, read-only board type information.
  *
  * The @detach handler has two roles.  If a COMEDI device was successfully
  * configured by the @attach or @auto_attach handler, it is called when the
  * device is being deconfigured (by the %COMEDI_DEVCONFIG ioctl, or due to
  * unloading of the driver, or due to device removal).  It is also called when
  * the @attach or @auto_attach handler returns an error.  Therefore, the
  * @attach or @auto_attach handlers can defer clean-up on error until the
  * @detach handler is called.  If the @attach or @auto_attach handlers free
  * any resources themselves, they must prevent the @detach handler from
  * freeing the same resources.  The @detach handler must not assume that all
  * resources requested by the @attach or @auto_attach handler were
  * successfully allocated.
  */
 struct comedi_driver {
     /* private: */
     struct comedi_driver *next; /* Next in list of COMEDI drivers. */
     /* public: */
     const char *driver_name;
     struct module *module;
     int (*attach)(struct comedi_device *dev, struct comedi_devconfig *it);
     void (*detach)(struct comedi_device *dev);
     int (*auto_attach)(struct comedi_device *dev, unsigned long context);
     unsigned int num_names;
     const char *const *board_name;
     int offset;
 };
 
 /**
  * struct comedi_device - Working data for a COMEDI device
  * @use_count: Number of open file objects.
  * @driver: Low-level COMEDI driver attached to this COMEDI device.
  * @pacer: Optional pointer to a dynamically allocated acquisition pacer
  *  control.  It is freed automatically after the COMEDI device is
  *  detached from the low-level driver.
  * @private: Optional pointer to private data allocated by the low-level
  *  driver.  It is freed automatically after the COMEDI device is
  *  detached from the low-level driver.
  * @class_dev: Sysfs comediX device.
  * @minor: Minor device number of COMEDI char device (0-47).
  * @detach_count: Counter incremented every time the COMEDI device is detached.
  *  Used for checking a previous attachment is still valid.
  * @hw_dev: Optional pointer to the low-level hardware &struct device.  It is
  *  required for automatically configured COMEDI devices and optional for
  *  COMEDI devices configured by the %COMEDI_DEVCONFIG ioctl, although
  *  the bus-specific COMEDI functions only work if it is set correctly.
  *  It is also passed to dma_alloc_coherent() for COMEDI subdevices that
  *  have their 'async_dma_dir' member set to something other than
  *  %DMA_NONE.
  * @board_name: Pointer to a COMEDI board name or a COMEDI driver name.  When
  *  the low-level driver's "attach" handler is called by the handler for
  *  the %COMEDI_DEVCONFIG ioctl, it either points to a matched board name
  *  string if the 'num_names' member of the &struct comedi_driver is
  *  non-zero, otherwise it points to the low-level driver name string.
  *  When the low-lever driver's "auto_attach" handler is called for an
  *  automatically configured COMEDI device, it points to the low-level
  *  driver name string.  The low-level driver is free to change it in its
  *  "attach" or "auto_attach" handler if it wishes.
  * @board_ptr: Optional pointer to private, read-only board type information in
  *  the low-level driver.  If the 'num_names' member of the &struct
  *  comedi_driver is non-zero, the handler for the %COMEDI_DEVCONFIG ioctl
  *  will point it to a pointer to a matched board name string within the
  *  driver's private array of static, read-only board type information when
  *  calling the driver's "attach" handler.  The low-level driver is free to
  *  change it.
  * @attached: Flag indicating that the COMEDI device is attached to a low-level
  *  driver.
  * @ioenabled: Flag used to indicate that a PCI device has been enabled and
  *  its regions requested.
  * @spinlock: Generic spin-lock for use by the low-level driver.
  * @mutex: Generic mutex for use by the COMEDI core module.
  * @attach_lock: &struct rw_semaphore used to guard against the COMEDI device
  *  being detached while an operation is in progress.  The down_write()
  *  operation is only allowed while @mutex is held and is used when
  *  changing @attached and @detach_count and calling the low-level driver's
  *  "detach" handler.  The down_read() operation is generally used without
  *  holding @mutex.
  * @refcount: &struct kref reference counter for freeing COMEDI device.
  * @n_subdevices: Number of COMEDI subdevices allocated by the low-level
  *  driver for this device.
  * @subdevices: Dynamically allocated array of COMEDI subdevices.
  * @mmio: Optional pointer to a remapped MMIO region set by the low-level
  *  driver.
  * @iobase: Optional base of an I/O port region requested by the low-level
  *  driver.
  * @iolen: Length of I/O port region requested at @iobase.
  * @irq: Optional IRQ number requested by the low-level driver.
  * @read_subdev: Optional pointer to a default COMEDI subdevice operated on by
  *  the read() file operation.  Set by the low-level driver.
  * @write_subdev: Optional pointer to a default COMEDI subdevice operated on by
  *  the write() file operation.  Set by the low-level driver.
  * @async_queue: Storage for fasync_helper().
  * @open: Optional pointer to a function set by the low-level driver to be
  *  called when @use_count changes from 0 to 1.
  * @close: Optional pointer to a function set by the low-level driver to be
  *  called when @use_count changed from 1 to 0.
  * @insn_device_config: Optional pointer to a handler for all sub-instructions
  *  except %INSN_DEVICE_CONFIG_GET_ROUTES of the %INSN_DEVICE_CONFIG
  *  instruction.  If this is not initialized by the low-level driver, a
  *  default handler will be set during post-configuration.
  * @get_valid_routes: Optional pointer to a handler for the
  *  %INSN_DEVICE_CONFIG_GET_ROUTES sub-instruction of the
  *  %INSN_DEVICE_CONFIG instruction set.  If this is not initialized by the
  *  low-level driver, a default handler that copies zero routes back to the
  *  user will be used.
  *
  * This is the main control data structure for a COMEDI device (as far as the
  * COMEDI core is concerned).  There are two groups of COMEDI devices -
  * "legacy" devices that are configured by the handler for the
  * %COMEDI_DEVCONFIG ioctl, and automatically configured devices resulting
  * from a call to comedi_auto_config() as a result of a bus driver probe in
  * a low-level COMEDI driver.  The "legacy" COMEDI devices are allocated
  * during module initialization if the "comedi_num_legacy_minors" module
  * parameter is non-zero and use minor device numbers from 0 to
  * comedi_num_legacy_minors minus one.  The automatically configured COMEDI
  * devices are allocated on demand and use minor device numbers from
  * comedi_num_legacy_minors to 47.
  */
 struct comedi_device {
     int use_count;
     struct comedi_driver *driver;
     struct comedi_8254 *pacer;
     void *private;
 
     struct device *class_dev;
     int minor;
     unsigned int detach_count;
     struct device *hw_dev;
 
     const char *board_name;
     const void *board_ptr;
     unsigned int attached:1;
     unsigned int ioenabled:1;
     spinlock_t spinlock;    /* generic spin-lock for low-level driver */
     struct mutex mutex; /* generic mutex for COMEDI core */
     struct rw_semaphore attach_lock;
     struct kref refcount;
 
     int n_subdevices;
     struct comedi_subdevice *subdevices;
 
     /* dumb */
     void __iomem *mmio;
     unsigned long iobase;
     unsigned long iolen;
     unsigned int irq;
 
     struct comedi_subdevice *read_subdev;
     struct comedi_subdevice *write_subdev;
 
     struct fasync_struct *async_queue;
 
     int (*open)(struct comedi_device *dev);
     void (*close)(struct comedi_device *dev);
     int (*insn_device_config)(struct comedi_device *dev,
                   struct comedi_insn *insn, unsigned int *data);
     unsigned int (*get_valid_routes)(struct comedi_device *dev,
                      unsigned int n_pairs,
                      unsigned int *pair_data);
 };
 
 /*
  * function prototypes
  */
 
 void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s);
 
 struct comedi_device *comedi_dev_get_from_minor(unsigned int minor);
 int comedi_dev_put(struct comedi_device *dev);
 
 bool comedi_is_subdevice_running(struct comedi_subdevice *s);
 
 void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size);
 void comedi_set_spriv_auto_free(struct comedi_subdevice *s);
 
 int comedi_check_chanlist(struct comedi_subdevice *s,
               int n,
               unsigned int *chanlist);
 
 /* range stuff */
 
 #define RANGE(a, b)     {(a) * 1e6, (b) * 1e6, 0}
 #define RANGE_ext(a, b)     {(a) * 1e6, (b) * 1e6, RF_EXTERNAL}
 #define RANGE_mA(a, b)      {(a) * 1e6, (b) * 1e6, UNIT_mA}
 #define RANGE_unitless(a, b)    {(a) * 1e6, (b) * 1e6, 0}
 #define BIP_RANGE(a)        {-(a) * 1e6, (a) * 1e6, 0}
 #define UNI_RANGE(a)        {0, (a) * 1e6, 0}
 
 extern const struct comedi_lrange range_bipolar10;
 extern const struct comedi_lrange range_bipolar5;
 extern const struct comedi_lrange range_bipolar2_5;
 extern const struct comedi_lrange range_unipolar10;
 extern const struct comedi_lrange range_unipolar5;
 extern const struct comedi_lrange range_unipolar2_5;
 extern const struct comedi_lrange range_0_20mA;
 extern const struct comedi_lrange range_4_20mA;
 extern const struct comedi_lrange range_0_32mA;
 extern const struct comedi_lrange range_unknown;
 
 #define range_digital       range_unipolar5
 
 /**
  * struct comedi_lrange - Describes a COMEDI range table
  * @length: Number of entries in the range table.
  * @range: Array of &struct comedi_krange, one for each range.
  *
  * Each element of @range[] describes the minimum and maximum physical range
  * and the type of units.  Typically, the type of unit is %UNIT_volt
  * (i.e. volts) and the minimum and maximum are in millionths of a volt.
  * There may also be a flag that indicates the minimum and maximum are merely
  * scale factors for an unknown, external reference.
  */
 struct comedi_lrange {
     int length;
     struct comedi_krange range[];
 };
 
 /**
  * comedi_range_is_bipolar() - Test if subdevice range is bipolar
  * @s: COMEDI subdevice.
  * @range: Index of range within a range table.
  *
  * Tests whether a range is bipolar by checking whether its minimum value
  * is negative.
  *
  * Assumes @range is valid.  Does not work for subdevices using a
  * channel-specific range table list.
  *
  * Return:
  *  %true if the range is bipolar.
  *  %false if the range is unipolar.
  */
 static inline bool comedi_range_is_bipolar(struct comedi_subdevice *s,
                        unsigned int range)
 {
     return s->range_table->range[range].min < 0;
 }
 
 /**
  * comedi_range_is_unipolar() - Test if subdevice range is unipolar
  * @s: COMEDI subdevice.
  * @range: Index of range within a range table.
  *
  * Tests whether a range is unipolar by checking whether its minimum value
  * is at least 0.
  *
  * Assumes @range is valid.  Does not work for subdevices using a
  * channel-specific range table list.
  *
  * Return:
  *  %true if the range is unipolar.
  *  %false if the range is bipolar.
  */
 static inline bool comedi_range_is_unipolar(struct comedi_subdevice *s,
                         unsigned int range)
 {
     return s->range_table->range[range].min >= 0;
 }
 
 /**
  * comedi_range_is_external() - Test if subdevice range is external
  * @s: COMEDI subdevice.
  * @range: Index of range within a range table.
  *
  * Tests whether a range is externally reference by checking whether its
  * %RF_EXTERNAL flag is set.
  *
  * Assumes @range is valid.  Does not work for subdevices using a
  * channel-specific range table list.
  *
  * Return:
  *  %true if the range is external.
  *  %false if the range is internal.
  */
 static inline bool comedi_range_is_external(struct comedi_subdevice *s,
                         unsigned int range)
 {
     return !!(s->range_table->range[range].flags & RF_EXTERNAL);
 }
 
 /**
  * comedi_chan_range_is_bipolar() - Test if channel-specific range is bipolar
  * @s: COMEDI subdevice.
  * @chan: The channel number.
  * @range: Index of range within a range table.
  *
  * Tests whether a range is bipolar by checking whether its minimum value
  * is negative.
  *
  * Assumes @chan and @range are valid.  Only works for subdevices with a
  * channel-specific range table list.
  *
  * Return:
  *  %true if the range is bipolar.
  *  %false if the range is unipolar.
  */
 static inline bool comedi_chan_range_is_bipolar(struct comedi_subdevice *s,
                         unsigned int chan,
                         unsigned int range)
 {
     return s->range_table_list[chan]->range[range].min < 0;
 }
 
 /**
  * comedi_chan_range_is_unipolar() - Test if channel-specific range is unipolar
  * @s: COMEDI subdevice.
  * @chan: The channel number.
  * @range: Index of range within a range table.
  *
  * Tests whether a range is unipolar by checking whether its minimum value
  * is at least 0.
  *
  * Assumes @chan and @range are valid.  Only works for subdevices with a
  * channel-specific range table list.
  *
  * Return:
  *  %true if the range is unipolar.
  *  %false if the range is bipolar.
  */
 static inline bool comedi_chan_range_is_unipolar(struct comedi_subdevice *s,
                          unsigned int chan,
                          unsigned int range)
 {
     return s->range_table_list[chan]->range[range].min >= 0;
 }
 
 /**
  * comedi_chan_range_is_external() - Test if channel-specific range is external
  * @s: COMEDI subdevice.
  * @chan: The channel number.
  * @range: Index of range within a range table.
  *
  * Tests whether a range is externally reference by checking whether its
  * %RF_EXTERNAL flag is set.
  *
  * Assumes @chan and @range are valid.  Only works for subdevices with a
  * channel-specific range table list.
  *
  * Return:
  *  %true if the range is bipolar.
  *  %false if the range is unipolar.
  */
 static inline bool comedi_chan_range_is_external(struct comedi_subdevice *s,
                          unsigned int chan,
                          unsigned int range)
 {
     return !!(s->range_table_list[chan]->range[range].flags & RF_EXTERNAL);
 }
 
 /**
  * comedi_offset_munge() - Convert between offset binary and 2's complement
  * @s: COMEDI subdevice.
  * @val: Value to be converted.
  *
  * Toggles the highest bit of a sample value to toggle between offset binary
  * and 2's complement.  Assumes that @s->maxdata is a power of 2 minus 1.
  *
  * Return: The converted value.
  */
 static inline unsigned int comedi_offset_munge(struct comedi_subdevice *s,
                            unsigned int val)
 {
     return val ^ s->maxdata ^ (s->maxdata >> 1);
 }
 
 /**
  * comedi_bytes_per_sample() - Determine subdevice sample size
  * @s: COMEDI subdevice.
  *
  * The sample size will be 4 (sizeof int) or 2 (sizeof short) depending on
  * whether the %SDF_LSAMPL subdevice flag is set or not.
  *
  * Return: The subdevice sample size.
  */
 static inline unsigned int comedi_bytes_per_sample(struct comedi_subdevice *s)
 {
     return s->subdev_flags & SDF_LSAMPL ? sizeof(int) : sizeof(short);
 }
 
 /**
  * comedi_sample_shift() - Determine log2 of subdevice sample size
  * @s: COMEDI subdevice.
  *
  * The sample size will be 4 (sizeof int) or 2 (sizeof short) depending on
  * whether the %SDF_LSAMPL subdevice flag is set or not.  The log2 of the
  * sample size will be 2 or 1 and can be used as the right operand of a
  * bit-shift operator to multiply or divide something by the sample size.
  *
  * Return: log2 of the subdevice sample size.
  */
 static inline unsigned int comedi_sample_shift(struct comedi_subdevice *s)
 {
     return s->subdev_flags & SDF_LSAMPL ? 2 : 1;
 }
 
 /**
  * comedi_bytes_to_samples() - Convert a number of bytes to a number of samples
  * @s: COMEDI subdevice.
  * @nbytes: Number of bytes
  *
  * Return: The number of bytes divided by the subdevice sample size.
  */
 static inline unsigned int comedi_bytes_to_samples(struct comedi_subdevice *s,
                            unsigned int nbytes)
 {
     return nbytes >> comedi_sample_shift(s);
 }
 
 /**
  * comedi_samples_to_bytes() - Convert a number of samples to a number of bytes
  * @s: COMEDI subdevice.
  * @nsamples: Number of samples.
  *
  * Return: The number of samples multiplied by the subdevice sample size.
  * (Does not check for arithmetic overflow.)
  */
 static inline unsigned int comedi_samples_to_bytes(struct comedi_subdevice *s,
                            unsigned int nsamples)
 {
     return nsamples << comedi_sample_shift(s);
 }
 
 /**
  * comedi_check_trigger_src() - Trivially validate a comedi_cmd trigger source
  * @src: Pointer to the trigger source to validate.
  * @flags: Bitmask of valid %TRIG_* for the trigger.
  *
  * This is used in "step 1" of the do_cmdtest functions of comedi drivers
  * to validate the comedi_cmd triggers. The mask of the @src against the
  * @flags allows the userspace comedilib to pass all the comedi_cmd
  * triggers as %TRIG_ANY and get back a bitmask of the valid trigger sources.
  *
  * Return:
  *  0 if trigger sources in *@src are all supported.
  *  -EINVAL if any trigger source in *@src is unsupported.
  */
 static inline int comedi_check_trigger_src(unsigned int *src,
                        unsigned int flags)
 {
     unsigned int orig_src = *src;
 
     *src = orig_src & flags;
     if (*src == TRIG_INVALID || *src != orig_src)
         return -EINVAL;
     return 0;
 }
 
 /**
  * comedi_check_trigger_is_unique() - Make sure a trigger source is unique
  * @src: The trigger source to check.
  *
  * Return:
  *  0 if no more than one trigger source is set.
  *  -EINVAL if more than one trigger source is set.
  */
 static inline int comedi_check_trigger_is_unique(unsigned int src)
 {
     /* this test is true if more than one _src bit is set */
     if ((src & (src - 1)) != 0)
         return -EINVAL;
     return 0;
 }
 
 /**
  * comedi_check_trigger_arg_is() - Trivially validate a trigger argument
  * @arg: Pointer to the trigger arg to validate.
  * @val: The value the argument should be.
  *
  * Forces *@arg to be @val.
  *
  * Return:
  *  0 if *@arg was already @val.
  *  -EINVAL if *@arg differed from @val.
  */
 static inline int comedi_check_trigger_arg_is(unsigned int *arg,
                           unsigned int val)
 {
     if (*arg != val) {
         *arg = val;
         return -EINVAL;
     }
     return 0;
 }
 
 /**
  * comedi_check_trigger_arg_min() - Trivially validate a trigger argument min
  * @arg: Pointer to the trigger arg to validate.
  * @val: The minimum value the argument should be.
  *
  * Forces *@arg to be at least @val, setting it to @val if necessary.
  *
  * Return:
  *  0 if *@arg was already at least @val.
  *  -EINVAL if *@arg was less than @val.
  */
 static inline int comedi_check_trigger_arg_min(unsigned int *arg,
                            unsigned int val)
 {
     if (*arg < val) {
         *arg = val;
         return -EINVAL;
     }
     return 0;
 }
 
 /**
  * comedi_check_trigger_arg_max() - Trivially validate a trigger argument max
  * @arg: Pointer to the trigger arg to validate.
  * @val: The maximum value the argument should be.
  *
  * Forces *@arg to be no more than @val, setting it to @val if necessary.
  *
  * Return:
  *  0 if*@arg was already no more than @val.
  *  -EINVAL if *@arg was greater than @val.
  */
 static inline int comedi_check_trigger_arg_max(unsigned int *arg,
                            unsigned int val)
 {
     if (*arg > val) {
         *arg = val;
         return -EINVAL;
     }
     return 0;
 }
 
 /*
  * Must set dev->hw_dev if you wish to dma directly into comedi's buffer.
  * Also useful for retrieving a previously configured hardware device of
  * known bus type.  Set automatically for auto-configured devices.
  * Automatically set to NULL when detaching hardware device.
  */
 int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev);
 
 /**
  * comedi_buf_n_bytes_ready - Determine amount of unread data in buffer
  * @s: COMEDI subdevice.
  *
  * Determines the number of bytes of unread data in the asynchronous
  * acquisition data buffer for a subdevice.  The data in question might not
  * have been fully "munged" yet.
  *
  * Returns: The amount of unread data in bytes.
  */
 static inline unsigned int comedi_buf_n_bytes_ready(struct comedi_subdevice *s)
 {
     return s->async->buf_write_count - s->async->buf_read_count;
 }
 
 unsigned int comedi_buf_write_alloc(struct comedi_subdevice *s, unsigned int n);
 unsigned int comedi_buf_write_free(struct comedi_subdevice *s, unsigned int n);
 
 unsigned int comedi_buf_read_n_available(struct comedi_subdevice *s);
 unsigned int comedi_buf_read_alloc(struct comedi_subdevice *s, unsigned int n);
 unsigned int comedi_buf_read_free(struct comedi_subdevice *s, unsigned int n);
 
 unsigned int comedi_buf_write_samples(struct comedi_subdevice *s,
                       const void *data, unsigned int nsamples);
 unsigned int comedi_buf_read_samples(struct comedi_subdevice *s,
                      void *data, unsigned int nsamples);
 
 /* drivers.c - general comedi driver functions */
 
 #define COMEDI_TIMEOUT_MS   1000
 
 int comedi_timeout(struct comedi_device *dev, struct comedi_subdevice *s,
            struct comedi_insn *insn,
            int (*cb)(struct comedi_device *dev,
                  struct comedi_subdevice *s,
                  struct comedi_insn *insn, unsigned long context),
            unsigned long context);
 
 unsigned int comedi_handle_events(struct comedi_device *dev,
                   struct comedi_subdevice *s);
 
 int comedi_dio_insn_config(struct comedi_device *dev,
                struct comedi_subdevice *s,
                struct comedi_insn *insn, unsigned int *data,
                unsigned int mask);
 unsigned int comedi_dio_update_state(struct comedi_subdevice *s,
                      unsigned int *data);
 unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s,
                        struct comedi_cmd *cmd);
 unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s);
 unsigned int comedi_nscans_left(struct comedi_subdevice *s,
                 unsigned int nscans);
 unsigned int comedi_nsamples_left(struct comedi_subdevice *s,
                   unsigned int nsamples);
 void comedi_inc_scan_progress(struct comedi_subdevice *s,
                   unsigned int num_bytes);
 
 void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size);
 int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices);
 int comedi_alloc_subdev_readback(struct comedi_subdevice *s);
 
 int comedi_readback_insn_read(struct comedi_device *dev,
                   struct comedi_subdevice *s,
                   struct comedi_insn *insn, unsigned int *data);
 
 int comedi_load_firmware(struct comedi_device *dev, struct device *hw_dev,
              const char *name,
              int (*cb)(struct comedi_device *dev,
                    const u8 *data, size_t size,
                    unsigned long context),
              unsigned long context);
 
 int __comedi_request_region(struct comedi_device *dev,
                 unsigned long start, unsigned long len);
 int comedi_request_region(struct comedi_device *dev,
               unsigned long start, unsigned long len);
 void comedi_legacy_detach(struct comedi_device *dev);
 
 int comedi_auto_config(struct device *hardware_device,
                struct comedi_driver *driver, unsigned long context);
 void comedi_auto_unconfig(struct device *hardware_device);
 
 int comedi_driver_register(struct comedi_driver *driver);
 void comedi_driver_unregister(struct comedi_driver *driver);
 
 /**
  * module_comedi_driver() - Helper macro for registering a comedi driver
  * @__comedi_driver: comedi_driver struct
  *
  * Helper macro for comedi drivers which do not do anything special in module
  * init/exit. This eliminates a lot of boilerplate. Each module may only use
  * this macro once, and calling it replaces module_init() and module_exit().
  */
 #define module_comedi_driver(__comedi_driver) \
     module_driver(__comedi_driver, comedi_driver_register, \
             comedi_driver_unregister)
 
 #endif /* _COMEDIDEV_H */

This page was automatically generated by the 2.1.0 LXR engine. The LXR team