diff options
Diffstat (limited to 'drivers/staging/comedi/comedidev.h')
| -rw-r--r-- | drivers/staging/comedi/comedidev.h | 635 |
1 files changed, 525 insertions, 110 deletions
diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h index 28a5d3a037a1..115807215484 100644 --- a/drivers/staging/comedi/comedidev.h +++ b/drivers/staging/comedi/comedidev.h @@ -1,20 +1,20 @@ /* - include/linux/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> - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. -*/ + * 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> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ #ifndef _COMEDIDEV_H #define _COMEDIDEV_H @@ -34,6 +34,131 @@ #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; @@ -49,7 +174,7 @@ struct comedi_subdevice { void *lock; void *busy; unsigned runflags; - spinlock_t spin_lock; + spinlock_t spin_lock; /* generic spin-lock for COMEDI and drivers */ unsigned int io_bits; @@ -92,11 +217,40 @@ struct comedi_subdevice { 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; @@ -106,61 +260,66 @@ struct comedi_buf_map { }; /** - * struct comedi_async - control data for asynchronous comedi commands - * @prealloc_buf: preallocated buffer - * @prealloc_bufsz: buffer size (in bytes) - * @buf_map: map of buffer pages - * @max_bufsize: maximum 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 (COMEDI_CB_EOS) - * @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 + * 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: + * 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: + * (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 * @@ -216,43 +375,153 @@ struct comedi_async { }; /** - * comedi_async callback "events" + * 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 */ -#define COMEDI_CB_EOS BIT(0) -#define COMEDI_CB_EOA BIT(1) -#define COMEDI_CB_BLOCK BIT(2) -#define COMEDI_CB_EOBUF BIT(3) -#define COMEDI_CB_ERROR BIT(4) -#define COMEDI_CB_OVERFLOW BIT(5) - -#define COMEDI_CB_ERROR_MASK (COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW) -#define COMEDI_CB_CANCEL_MASK (COMEDI_CB_EOA | COMEDI_CB_ERROR_MASK) +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. + */ struct comedi_driver { - struct comedi_driver *next; - + /* private: */ + struct comedi_driver *next; /* Next in list of COMEDI drivers. */ + /* public: */ const char *driver_name; struct module *module; int (*attach)(struct comedi_device *, struct comedi_devconfig *); void (*detach)(struct comedi_device *); int (*auto_attach)(struct comedi_device *, unsigned long); - - /* number of elements in board_name and board_id arrays */ unsigned int num_names; const char *const *board_name; - /* offset in bytes from one board name pointer to the next */ 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. + * + * 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; @@ -262,17 +531,14 @@ struct comedi_device { struct device *class_dev; int minor; unsigned int detach_count; - /* hw_dev is passed to dma_alloc_coherent when allocating async buffers - * for subdevices that have async_dma_dir set to something other than - * DMA_NONE */ struct device *hw_dev; const char *board_name; const void *board_ptr; bool attached:1; bool ioenabled:1; - spinlock_t spinlock; - struct mutex mutex; + 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; @@ -314,12 +580,12 @@ int comedi_check_chanlist(struct comedi_subdevice *s, /* 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} +#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; @@ -340,29 +606,101 @@ extern const struct comedi_lrange range_unknown; #define GCC_ZERO_LENGTH_ARRAY 0 #endif +/** + * 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 + * 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[GCC_ZERO_LENGTH_ARRAY]; }; +/** + * 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) @@ -370,6 +708,22 @@ static inline bool comedi_chan_range_is_bipolar(struct comedi_subdevice *s, 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) @@ -377,6 +731,22 @@ static inline bool comedi_chan_range_is_unipolar(struct comedi_subdevice *s, 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) @@ -384,7 +754,16 @@ static inline bool comedi_chan_range_is_external(struct comedi_subdevice *s, return !!(s->range_table_list[chan]->range[range].flags & RF_EXTERNAL); } -/* munge between offset binary and two's complement values */ +/** + * 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) { @@ -392,13 +771,13 @@ static inline unsigned int comedi_offset_munge(struct comedi_subdevice *s, } /** - * comedi_bytes_per_sample - determine subdevice sample size - * @s: comedi_subdevice struct + * 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. + * whether the %SDF_LSAMPL subdevice flag is set or not. * - * Returns the subdevice sample size. + * Return: The subdevice sample size. */ static inline unsigned int comedi_bytes_per_sample(struct comedi_subdevice *s) { @@ -406,15 +785,15 @@ static inline unsigned int comedi_bytes_per_sample(struct comedi_subdevice *s) } /** - * comedi_sample_shift - determine log2 of subdevice sample size - * @s: comedi_subdevice struct + * 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 + * 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. * - * Returns log2 of the subdevice sample size. + * Return: log2 of the subdevice sample size. */ static inline unsigned int comedi_sample_shift(struct comedi_subdevice *s) { @@ -422,11 +801,11 @@ static inline unsigned int comedi_sample_shift(struct comedi_subdevice *s) } /** - * comedi_bytes_to_samples - converts a number of bytes to a number of samples - * @s: comedi_subdevice struct - * @nbytes: number of bytes + * comedi_bytes_to_samples() - Convert a number of bytes to a number of samples + * @s: COMEDI subdevice. + * @nbytes: Number of bytes * - * Returns the number of bytes divided by the subdevice sample size. + * 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) @@ -435,12 +814,12 @@ static inline unsigned int comedi_bytes_to_samples(struct comedi_subdevice *s, } /** - * comedi_samples_to_bytes - converts a number of samples to a number of bytes - * @s: comedi_subdevice struct - * @nsamples: number of samples + * comedi_samples_to_bytes() - Convert a number of samples to a number of bytes + * @s: COMEDI subdevice. + * @nsamples: Number of samples. * - * Returns the number of samples multiplied by the subdevice sample size. - * Does not check for arithmetic overflow. + * 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) @@ -449,14 +828,18 @@ static inline unsigned int comedi_samples_to_bytes(struct comedi_subdevice *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 + * 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 vaildate the comedi_cmd triggers. The mask of the @src against the + * 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. + * 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) @@ -470,8 +853,12 @@ static inline int comedi_check_trigger_src(unsigned int *src, } /** - * comedi_check_trigger_is_unique() - make sure a trigger source is unique - * @src: the trigger source to check + * 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) { @@ -482,9 +869,15 @@ static inline int comedi_check_trigger_is_unique(unsigned int src) } /** - * 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 + * 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) @@ -497,9 +890,15 @@ static inline int comedi_check_trigger_arg_is(unsigned int *arg, } /** - * comedi_check_trigger_arg_min() - trivially validate a trigger argument - * @arg: pointer to the trigger arg to validate - * @val: the minimum value the argument should be + * 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) @@ -512,9 +911,15 @@ static inline int comedi_check_trigger_arg_min(unsigned int *arg, } /** - * comedi_check_trigger_arg_max() - trivially validate a trigger argument - * @arg: pointer to the trigger arg to validate - * @val: the maximum value the argument should be + * 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) @@ -534,6 +939,16 @@ static inline int comedi_check_trigger_arg_max(unsigned int *arg, */ 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; |