Merge branch 'for-5.18/amd-sfh' into for-linus

- dead code elimination (Christophe JAILLET)

20 files changed, 1986 insertions, 89 deletions

diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 9176a095fefc..8eda133ca4c1 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -514,7 +514,7 @@ struct audit_rule_data {
 	__u32		values[AUDIT_MAX_FIELDS];
 	__u32		fieldflags[AUDIT_MAX_FIELDS];
 	__u32		buflen;	/* total length of string fields */
-	char		buf[0];	/* string fields buffer */
+	char		buf[];	/* string fields buffer */
 };
 
 #endif /* _UAPI_LINUX_AUDIT_H_ */
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index e1c4c732aaba..5416f1f1a77a 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -146,7 +146,9 @@
 
 /*
  * dir items are the name -> inode pointers in a directory.  There is one
- * for every name in a directory.
+ * for every name in a directory.  BTRFS_DIR_LOG_ITEM_KEY is no longer used
+ * but it's still defined here for documentation purposes and to help avoid
+ * having its numerical value reused in the future.
  */
 #define BTRFS_DIR_LOG_ITEM_KEY  60
 #define BTRFS_DIR_LOG_INDEX_KEY 72
diff --git a/include/uapi/linux/comedi.h b/include/uapi/linux/comedi.h
new file mode 100644
index 000000000000..7314e5ee0a1e
--- /dev/null
+++ b/include/uapi/linux/comedi.h
@@ -0,0 +1,1528 @@
+/* SPDX-License-Identifier: LGPL-2.0+ WITH Linux-syscall-note */
+/*
+ * comedi.h
+ * header file for COMEDI user API
+ *
+ * COMEDI - Linux Control and Measurement Device Interface
+ * Copyright (C) 1998-2001 David A. Schleef <ds@schleef.org>
+ */
+
+#ifndef _COMEDI_H
+#define _COMEDI_H
+
+#define COMEDI_MAJORVERSION	0
+#define COMEDI_MINORVERSION	7
+#define COMEDI_MICROVERSION	76
+#define VERSION	"0.7.76"
+
+/* comedi's major device number */
+#define COMEDI_MAJOR 98
+
+/*
+ * maximum number of minor devices.  This can be increased, although
+ * kernel structures are currently statically allocated, thus you
+ * don't want this to be much more than you actually use.
+ */
+#define COMEDI_NDEVICES 16
+
+/* number of config options in the config structure */
+#define COMEDI_NDEVCONFOPTS 32
+
+/*
+ * NOTE: 'comedi_config --init-data' is deprecated
+ *
+ * The following indexes in the config options were used by
+ * comedi_config to pass firmware blobs from user space to the
+ * comedi drivers. The request_firmware() hotplug interface is
+ * now used by all comedi drivers instead.
+ */
+
+/* length of nth chunk of firmware data -*/
+#define COMEDI_DEVCONF_AUX_DATA3_LENGTH		25
+#define COMEDI_DEVCONF_AUX_DATA2_LENGTH		26
+#define COMEDI_DEVCONF_AUX_DATA1_LENGTH		27
+#define COMEDI_DEVCONF_AUX_DATA0_LENGTH		28
+/* most significant 32 bits of pointer address (if needed) */
+#define COMEDI_DEVCONF_AUX_DATA_HI		29
+/* least significant 32 bits of pointer address */
+#define COMEDI_DEVCONF_AUX_DATA_LO		30
+#define COMEDI_DEVCONF_AUX_DATA_LENGTH		31	/* total data length */
+
+/* max length of device and driver names */
+#define COMEDI_NAMELEN 20
+
+/* packs and unpacks a channel/range number */
+
+#define CR_PACK(chan, rng, aref)					\
+	((((aref) & 0x3) << 24) | (((rng) & 0xff) << 16) | (chan))
+#define CR_PACK_FLAGS(chan, range, aref, flags)				\
+	(CR_PACK(chan, range, aref) | ((flags) & CR_FLAGS_MASK))
+
+#define CR_CHAN(a)	((a) & 0xffff)
+#define CR_RANGE(a)	(((a) >> 16) & 0xff)
+#define CR_AREF(a)	(((a) >> 24) & 0x03)
+
+#define CR_FLAGS_MASK	0xfc000000
+#define CR_ALT_FILTER	0x04000000
+#define CR_DITHER	CR_ALT_FILTER
+#define CR_DEGLITCH	CR_ALT_FILTER
+#define CR_ALT_SOURCE	0x08000000
+#define CR_EDGE		0x40000000
+#define CR_INVERT	0x80000000
+
+#define AREF_GROUND	0x00	/* analog ref = analog ground */
+#define AREF_COMMON	0x01	/* analog ref = analog common */
+#define AREF_DIFF	0x02	/* analog ref = differential */
+#define AREF_OTHER	0x03	/* analog ref = other (undefined) */
+
+/* counters -- these are arbitrary values */
+#define GPCT_RESET		0x0001
+#define GPCT_SET_SOURCE		0x0002
+#define GPCT_SET_GATE		0x0004
+#define GPCT_SET_DIRECTION	0x0008
+#define GPCT_SET_OPERATION	0x0010
+#define GPCT_ARM		0x0020
+#define GPCT_DISARM		0x0040
+#define GPCT_GET_INT_CLK_FRQ	0x0080
+
+#define GPCT_INT_CLOCK		0x0001
+#define GPCT_EXT_PIN		0x0002
+#define GPCT_NO_GATE		0x0004
+#define GPCT_UP			0x0008
+#define GPCT_DOWN		0x0010
+#define GPCT_HWUD		0x0020
+#define GPCT_SIMPLE_EVENT	0x0040
+#define GPCT_SINGLE_PERIOD	0x0080
+#define GPCT_SINGLE_PW		0x0100
+#define GPCT_CONT_PULSE_OUT	0x0200
+#define GPCT_SINGLE_PULSE_OUT	0x0400
+
+/* instructions */
+
+#define INSN_MASK_WRITE		0x8000000
+#define INSN_MASK_READ		0x4000000
+#define INSN_MASK_SPECIAL	0x2000000
+
+#define INSN_READ		(0 | INSN_MASK_READ)
+#define INSN_WRITE		(1 | INSN_MASK_WRITE)
+#define INSN_BITS		(2 | INSN_MASK_READ | INSN_MASK_WRITE)
+#define INSN_CONFIG		(3 | INSN_MASK_READ | INSN_MASK_WRITE)
+#define INSN_DEVICE_CONFIG	(INSN_CONFIG | INSN_MASK_SPECIAL)
+#define INSN_GTOD		(4 | INSN_MASK_READ | INSN_MASK_SPECIAL)
+#define INSN_WAIT		(5 | INSN_MASK_WRITE | INSN_MASK_SPECIAL)
+#define INSN_INTTRIG		(6 | INSN_MASK_WRITE | INSN_MASK_SPECIAL)
+
+/* command flags */
+/* These flags are used in comedi_cmd structures */
+
+#define CMDF_BOGUS		0x00000001	/* do the motions */
+
+/* try to use a real-time interrupt while performing command */
+#define CMDF_PRIORITY		0x00000008
+
+/* wake up on end-of-scan events */
+#define CMDF_WAKE_EOS		0x00000020
+
+#define CMDF_WRITE		0x00000040
+
+#define CMDF_RAWDATA		0x00000080
+
+/* timer rounding definitions */
+#define CMDF_ROUND_MASK		0x00030000
+#define CMDF_ROUND_NEAREST	0x00000000
+#define CMDF_ROUND_DOWN		0x00010000
+#define CMDF_ROUND_UP		0x00020000
+#define CMDF_ROUND_UP_NEXT	0x00030000
+
+#define COMEDI_EV_START		0x00040000
+#define COMEDI_EV_SCAN_BEGIN	0x00080000
+#define COMEDI_EV_CONVERT	0x00100000
+#define COMEDI_EV_SCAN_END	0x00200000
+#define COMEDI_EV_STOP		0x00400000
+
+/* compatibility definitions */
+#define TRIG_BOGUS		CMDF_BOGUS
+#define TRIG_RT			CMDF_PRIORITY
+#define TRIG_WAKE_EOS		CMDF_WAKE_EOS
+#define TRIG_WRITE		CMDF_WRITE
+#define TRIG_ROUND_MASK		CMDF_ROUND_MASK
+#define TRIG_ROUND_NEAREST	CMDF_ROUND_NEAREST
+#define TRIG_ROUND_DOWN		CMDF_ROUND_DOWN
+#define TRIG_ROUND_UP		CMDF_ROUND_UP
+#define TRIG_ROUND_UP_NEXT	CMDF_ROUND_UP_NEXT
+
+/* trigger sources */
+
+#define TRIG_ANY	0xffffffff
+#define TRIG_INVALID	0x00000000
+
+#define TRIG_NONE	0x00000001 /* never trigger */
+#define TRIG_NOW	0x00000002 /* trigger now + N ns */
+#define TRIG_FOLLOW	0x00000004 /* trigger on next lower level trig */
+#define TRIG_TIME	0x00000008 /* trigger at time N ns */
+#define TRIG_TIMER	0x00000010 /* trigger at rate N ns */
+#define TRIG_COUNT	0x00000020 /* trigger when count reaches N */
+#define TRIG_EXT	0x00000040 /* trigger on external signal N */
+#define TRIG_INT	0x00000080 /* trigger on comedi-internal signal N */
+#define TRIG_OTHER	0x00000100 /* driver defined */
+
+/* subdevice flags */
+
+#define SDF_BUSY	0x0001	/* device is busy */
+#define SDF_BUSY_OWNER	0x0002	/* device is busy with your job */
+#define SDF_LOCKED	0x0004	/* subdevice is locked */
+#define SDF_LOCK_OWNER	0x0008	/* you own lock */
+#define SDF_MAXDATA	0x0010	/* maxdata depends on channel */
+#define SDF_FLAGS	0x0020	/* flags depend on channel */
+#define SDF_RANGETYPE	0x0040	/* range type depends on channel */
+#define SDF_PWM_COUNTER 0x0080	/* PWM can automatically switch off */
+#define SDF_PWM_HBRIDGE 0x0100	/* PWM is signed (H-bridge) */
+#define SDF_CMD		0x1000	/* can do commands (deprecated) */
+#define SDF_SOFT_CALIBRATED	0x2000 /* subdevice uses software calibration */
+#define SDF_CMD_WRITE		0x4000 /* can do output commands */
+#define SDF_CMD_READ		0x8000 /* can do input commands */
+
+/* subdevice can be read (e.g. analog input) */
+#define SDF_READABLE	0x00010000
+/* subdevice can be written (e.g. analog output) */
+#define SDF_WRITABLE	0x00020000
+#define SDF_WRITEABLE	SDF_WRITABLE	/* spelling error in API */
+/* subdevice does not have externally visible lines */
+#define SDF_INTERNAL	0x00040000
+#define SDF_GROUND	0x00100000	/* can do aref=ground */
+#define SDF_COMMON	0x00200000	/* can do aref=common */
+#define SDF_DIFF	0x00400000	/* can do aref=diff */
+#define SDF_OTHER	0x00800000	/* can do aref=other */
+#define SDF_DITHER	0x01000000	/* can do dithering */
+#define SDF_DEGLITCH	0x02000000	/* can do deglitching */
+#define SDF_MMAP	0x04000000	/* can do mmap() */
+#define SDF_RUNNING	0x08000000	/* subdevice is acquiring data */
+#define SDF_LSAMPL	0x10000000	/* subdevice uses 32-bit samples */
+#define SDF_PACKED	0x20000000	/* subdevice can do packed DIO */
+
+/* subdevice types */
+
+/**
+ * enum comedi_subdevice_type - COMEDI subdevice types
+ * @COMEDI_SUBD_UNUSED:		Unused subdevice.
+ * @COMEDI_SUBD_AI:		Analog input.
+ * @COMEDI_SUBD_AO:		Analog output.
+ * @COMEDI_SUBD_DI:		Digital input.
+ * @COMEDI_SUBD_DO:		Digital output.
+ * @COMEDI_SUBD_DIO:		Digital input/output.
+ * @COMEDI_SUBD_COUNTER:	Counter.
+ * @COMEDI_SUBD_TIMER:		Timer.
+ * @COMEDI_SUBD_MEMORY:		Memory, EEPROM, DPRAM.
+ * @COMEDI_SUBD_CALIB:		Calibration DACs.
+ * @COMEDI_SUBD_PROC:		Processor, DSP.
+ * @COMEDI_SUBD_SERIAL:		Serial I/O.
+ * @COMEDI_SUBD_PWM:		Pulse-Width Modulation output.
+ */
+enum comedi_subdevice_type {
+	COMEDI_SUBD_UNUSED,
+	COMEDI_SUBD_AI,
+	COMEDI_SUBD_AO,
+	COMEDI_SUBD_DI,
+	COMEDI_SUBD_DO,
+	COMEDI_SUBD_DIO,
+	COMEDI_SUBD_COUNTER,
+	COMEDI_SUBD_TIMER,
+	COMEDI_SUBD_MEMORY,
+	COMEDI_SUBD_CALIB,
+	COMEDI_SUBD_PROC,
+	COMEDI_SUBD_SERIAL,
+	COMEDI_SUBD_PWM
+};
+
+/* configuration instructions */
+
+/**
+ * enum comedi_io_direction - COMEDI I/O directions
+ * @COMEDI_INPUT:	Input.
+ * @COMEDI_OUTPUT:	Output.
+ * @COMEDI_OPENDRAIN:	Open-drain (or open-collector) output.
+ *
+ * These are used by the %INSN_CONFIG_DIO_QUERY configuration instruction to
+ * report a direction.  They may also be used in other places where a direction
+ * needs to be specified.
+ */
+enum comedi_io_direction {
+	COMEDI_INPUT = 0,
+	COMEDI_OUTPUT = 1,
+	COMEDI_OPENDRAIN = 2
+};
+
+/**
+ * enum configuration_ids - COMEDI configuration instruction codes
+ * @INSN_CONFIG_DIO_INPUT:	Configure digital I/O as input.
+ * @INSN_CONFIG_DIO_OUTPUT:	Configure digital I/O as output.
+ * @INSN_CONFIG_DIO_OPENDRAIN:	Configure digital I/O as open-drain (or open
+ *				collector) output.
+ * @INSN_CONFIG_ANALOG_TRIG:	Configure analog trigger.
+ * @INSN_CONFIG_ALT_SOURCE:	Configure alternate input source.
+ * @INSN_CONFIG_DIGITAL_TRIG:	Configure digital trigger.
+ * @INSN_CONFIG_BLOCK_SIZE:	Configure block size for DMA transfers.
+ * @INSN_CONFIG_TIMER_1:	Configure divisor for external clock.
+ * @INSN_CONFIG_FILTER:		Configure a filter.
+ * @INSN_CONFIG_CHANGE_NOTIFY:	Configure change notification for digital
+ *				inputs.  (New drivers should use
+ *				%INSN_CONFIG_DIGITAL_TRIG instead.)
+ * @INSN_CONFIG_SERIAL_CLOCK:	Configure clock for serial I/O.
+ * @INSN_CONFIG_BIDIRECTIONAL_DATA: Send and receive byte over serial I/O.
+ * @INSN_CONFIG_DIO_QUERY:	Query direction of digital I/O channel.
+ * @INSN_CONFIG_PWM_OUTPUT:	Configure pulse-width modulator output.
+ * @INSN_CONFIG_GET_PWM_OUTPUT:	Get pulse-width modulator output configuration.
+ * @INSN_CONFIG_ARM:		Arm a subdevice or channel.
+ * @INSN_CONFIG_DISARM:		Disarm a subdevice or channel.
+ * @INSN_CONFIG_GET_COUNTER_STATUS: Get counter status.
+ * @INSN_CONFIG_RESET:		Reset a subdevice or channel.
+ * @INSN_CONFIG_GPCT_SINGLE_PULSE_GENERATOR: Configure counter/timer as
+ *				single pulse generator.
+ * @INSN_CONFIG_GPCT_PULSE_TRAIN_GENERATOR: Configure counter/timer as
+ *				pulse train generator.
+ * @INSN_CONFIG_GPCT_QUADRATURE_ENCODER: Configure counter as a quadrature
+ *				encoder.
+ * @INSN_CONFIG_SET_GATE_SRC:	Set counter/timer gate source.
+ * @INSN_CONFIG_GET_GATE_SRC:	Get counter/timer gate source.
+ * @INSN_CONFIG_SET_CLOCK_SRC:	Set counter/timer master clock source.
+ * @INSN_CONFIG_GET_CLOCK_SRC:	Get counter/timer master clock source.
+ * @INSN_CONFIG_SET_OTHER_SRC:	Set counter/timer "other" source.
+ * @INSN_CONFIG_GET_HARDWARE_BUFFER_SIZE: Get size (in bytes) of subdevice's
+ *				on-board FIFOs used during streaming
+ *				input/output.
+ * @INSN_CONFIG_SET_COUNTER_MODE: Set counter/timer mode.
+ * @INSN_CONFIG_8254_SET_MODE:	(Deprecated) Same as
+ *				%INSN_CONFIG_SET_COUNTER_MODE.
+ * @INSN_CONFIG_8254_READ_STATUS: Read status of 8254 counter channel.
+ * @INSN_CONFIG_SET_ROUTING:	Set routing for a channel.
+ * @INSN_CONFIG_GET_ROUTING:	Get routing for a channel.
+ * @INSN_CONFIG_PWM_SET_PERIOD: Set PWM period in nanoseconds.
+ * @INSN_CONFIG_PWM_GET_PERIOD: Get PWM period in nanoseconds.
+ * @INSN_CONFIG_GET_PWM_STATUS: Get PWM status.
+ * @INSN_CONFIG_PWM_SET_H_BRIDGE: Set PWM H bridge duty cycle and polarity for
+ *				a relay simultaneously.
+ * @INSN_CONFIG_PWM_GET_H_BRIDGE: Get PWM H bridge duty cycle and polarity.
+ * @INSN_CONFIG_GET_CMD_TIMING_CONSTRAINTS: Get the hardware timing restraints,
+ *				regardless of trigger sources.
+ */
+enum configuration_ids {
+	INSN_CONFIG_DIO_INPUT = COMEDI_INPUT,
+	INSN_CONFIG_DIO_OUTPUT = COMEDI_OUTPUT,
+	INSN_CONFIG_DIO_OPENDRAIN = COMEDI_OPENDRAIN,
+	INSN_CONFIG_ANALOG_TRIG = 16,
+/*	INSN_CONFIG_WAVEFORM = 17, */
+/*	INSN_CONFIG_TRIG = 18, */
+/*	INSN_CONFIG_COUNTER = 19, */
+	INSN_CONFIG_ALT_SOURCE = 20,
+	INSN_CONFIG_DIGITAL_TRIG = 21,
+	INSN_CONFIG_BLOCK_SIZE = 22,
+	INSN_CONFIG_TIMER_1 = 23,
+	INSN_CONFIG_FILTER = 24,
+	INSN_CONFIG_CHANGE_NOTIFY = 25,
+
+	INSN_CONFIG_SERIAL_CLOCK = 26,	/*ALPHA*/
+	INSN_CONFIG_BIDIRECTIONAL_DATA = 27,
+	INSN_CONFIG_DIO_QUERY = 28,
+	INSN_CONFIG_PWM_OUTPUT = 29,
+	INSN_CONFIG_GET_PWM_OUTPUT = 30,
+	INSN_CONFIG_ARM = 31,
+	INSN_CONFIG_DISARM = 32,
+	INSN_CONFIG_GET_COUNTER_STATUS = 33,
+	INSN_CONFIG_RESET = 34,
+	INSN_CONFIG_GPCT_SINGLE_PULSE_GENERATOR = 1001,
+	INSN_CONFIG_GPCT_PULSE_TRAIN_GENERATOR = 1002,
+	INSN_CONFIG_GPCT_QUADRATURE_ENCODER = 1003,
+	INSN_CONFIG_SET_GATE_SRC = 2001,
+	INSN_CONFIG_GET_GATE_SRC = 2002,
+	INSN_CONFIG_SET_CLOCK_SRC = 2003,
+	INSN_CONFIG_GET_CLOCK_SRC = 2004,
+	INSN_CONFIG_SET_OTHER_SRC = 2005,
+	INSN_CONFIG_GET_HARDWARE_BUFFER_SIZE = 2006,
+	INSN_CONFIG_SET_COUNTER_MODE = 4097,
+	INSN_CONFIG_8254_SET_MODE = INSN_CONFIG_SET_COUNTER_MODE,
+	INSN_CONFIG_8254_READ_STATUS = 4098,
+	INSN_CONFIG_SET_ROUTING = 4099,
+	INSN_CONFIG_GET_ROUTING = 4109,
+	INSN_CONFIG_PWM_SET_PERIOD = 5000,
+	INSN_CONFIG_PWM_GET_PERIOD = 5001,
+	INSN_CONFIG_GET_PWM_STATUS = 5002,
+	INSN_CONFIG_PWM_SET_H_BRIDGE = 5003,
+	INSN_CONFIG_PWM_GET_H_BRIDGE = 5004,
+	INSN_CONFIG_GET_CMD_TIMING_CONSTRAINTS = 5005,
+};
+
+/**
+ * enum device_configuration_ids - COMEDI configuration instruction codes global
+ * to an entire device.
+ * @INSN_DEVICE_CONFIG_TEST_ROUTE:	Validate the possibility of a
+ *					globally-named route
+ * @INSN_DEVICE_CONFIG_CONNECT_ROUTE:	Connect a globally-named route
+ * @INSN_DEVICE_CONFIG_DISCONNECT_ROUTE:Disconnect a globally-named route
+ * @INSN_DEVICE_CONFIG_GET_ROUTES:	Get a list of all globally-named routes
+ *					that are valid for a particular device.
+ */
+enum device_config_route_ids {
+	INSN_DEVICE_CONFIG_TEST_ROUTE = 0,
+	INSN_DEVICE_CONFIG_CONNECT_ROUTE = 1,
+	INSN_DEVICE_CONFIG_DISCONNECT_ROUTE = 2,
+	INSN_DEVICE_CONFIG_GET_ROUTES = 3,
+};
+
+/**
+ * enum comedi_digital_trig_op - operations for configuring a digital trigger
+ * @COMEDI_DIGITAL_TRIG_DISABLE:	Return digital trigger to its default,
+ *					inactive, unconfigured state.
+ * @COMEDI_DIGITAL_TRIG_ENABLE_EDGES:	Set rising and/or falling edge inputs
+ *					that each can fire the trigger.
+ * @COMEDI_DIGITAL_TRIG_ENABLE_LEVELS:	Set a combination of high and/or low
+ *					level inputs that can fire the trigger.
+ *
+ * These are used with the %INSN_CONFIG_DIGITAL_TRIG configuration instruction.
+ * The data for the configuration instruction is as follows...
+ *
+ *   data[%0] = %INSN_CONFIG_DIGITAL_TRIG
+ *
+ *   data[%1] = trigger ID
+ *
+ *   data[%2] = configuration operation
+ *
+ *   data[%3] = configuration parameter 1
+ *
+ *   data[%4] = configuration parameter 2
+ *
+ *   data[%5] = configuration parameter 3
+ *
+ * The trigger ID (data[%1]) is used to differentiate multiple digital triggers
+ * belonging to the same subdevice.  The configuration operation (data[%2]) is
+ * one of the enum comedi_digital_trig_op values.  The configuration
+ * parameters (data[%3], data[%4], and data[%5]) depend on the operation; they
+ * are not used with %COMEDI_DIGITAL_TRIG_DISABLE.
+ *
+ * For %COMEDI_DIGITAL_TRIG_ENABLE_EDGES and %COMEDI_DIGITAL_TRIG_ENABLE_LEVELS,
+ * configuration parameter 1 (data[%3]) contains a "left-shift" value that
+ * specifies the input corresponding to bit 0 of configuration parameters 2
+ * and 3.  This is useful if the trigger has more than 32 inputs.
+ *
+ * For %COMEDI_DIGITAL_TRIG_ENABLE_EDGES, configuration parameter 2 (data[%4])
+ * specifies which of up to 32 inputs have rising-edge sensitivity, and
+ * configuration parameter 3 (data[%5]) specifies which of up to 32 inputs
+ * have falling-edge sensitivity that can fire the trigger.
+ *
+ * For %COMEDI_DIGITAL_TRIG_ENABLE_LEVELS, configuration parameter 2 (data[%4])
+ * specifies which of up to 32 inputs must be at a high level, and
+ * configuration parameter 3 (data[%5]) specifies which of up to 32 inputs
+ * must be at a low level for the trigger to fire.
+ *
+ * Some sequences of %INSN_CONFIG_DIGITAL_TRIG instructions may have a (partly)
+ * accumulative effect, depending on the low-level driver.  This is useful
+ * when setting up a trigger that has more than 32 inputs, or has a combination
+ * of edge- and level-triggered inputs.
+ */
+enum comedi_digital_trig_op {
+	COMEDI_DIGITAL_TRIG_DISABLE = 0,
+	COMEDI_DIGITAL_TRIG_ENABLE_EDGES = 1,
+	COMEDI_DIGITAL_TRIG_ENABLE_LEVELS = 2
+};
+
+/**
+ * enum comedi_support_level - support level for a COMEDI feature
+ * @COMEDI_UNKNOWN_SUPPORT:	Unspecified support for feature.
+ * @COMEDI_SUPPORTED:		Feature is supported.
+ * @COMEDI_UNSUPPORTED:		Feature is unsupported.
+ */
+enum comedi_support_level {
+	COMEDI_UNKNOWN_SUPPORT = 0,
+	COMEDI_SUPPORTED,
+	COMEDI_UNSUPPORTED
+};
+
+/**
+ * enum comedi_counter_status_flags - counter status bits
+ * @COMEDI_COUNTER_ARMED:		Counter is armed.
+ * @COMEDI_COUNTER_COUNTING:		Counter is counting.
+ * @COMEDI_COUNTER_TERMINAL_COUNT:	Counter reached terminal count.
+ *
+ * These bitwise values are used by the %INSN_CONFIG_GET_COUNTER_STATUS
+ * configuration instruction to report the status of a counter.
+ */
+enum comedi_counter_status_flags {
+	COMEDI_COUNTER_ARMED = 0x1,
+	COMEDI_COUNTER_COUNTING = 0x2,
+	COMEDI_COUNTER_TERMINAL_COUNT = 0x4,
+};
+
+/* ioctls */
+
+#define CIO 'd'
+#define COMEDI_DEVCONFIG _IOW(CIO, 0, struct comedi_devconfig)
+#define COMEDI_DEVINFO _IOR(CIO, 1, struct comedi_devinfo)
+#define COMEDI_SUBDINFO _IOR(CIO, 2, struct comedi_subdinfo)
+#define COMEDI_CHANINFO _IOR(CIO, 3, struct comedi_chaninfo)
+/* _IOWR(CIO, 4, ...) is reserved */
+#define COMEDI_LOCK _IO(CIO, 5)
+#define COMEDI_UNLOCK _IO(CIO, 6)
+#define COMEDI_CANCEL _IO(CIO, 7)
+#define COMEDI_RANGEINFO _IOR(CIO, 8, struct comedi_rangeinfo)
+#define COMEDI_CMD _IOR(CIO, 9, struct comedi_cmd)
+#define COMEDI_CMDTEST _IOR(CIO, 10, struct comedi_cmd)
+#define COMEDI_INSNLIST _IOR(CIO, 11, struct comedi_insnlist)
+#define COMEDI_INSN _IOR(CIO, 12, struct comedi_insn)
+#define COMEDI_BUFCONFIG _IOR(CIO, 13, struct comedi_bufconfig)
+#define COMEDI_BUFINFO _IOWR(CIO, 14, struct comedi_bufinfo)
+#define COMEDI_POLL _IO(CIO, 15)
+#define COMEDI_SETRSUBD _IO(CIO, 16)
+#define COMEDI_SETWSUBD _IO(CIO, 17)
+
+/* structures */
+
+/**
+ * struct comedi_insn - COMEDI instruction
+ * @insn:	COMEDI instruction type (%INSN_xxx).
+ * @n:		Length of @data[].
+ * @data:	Pointer to data array operated on by the instruction.
+ * @subdev:	Subdevice index.
+ * @chanspec:	A packed "chanspec" value consisting of channel number,
+ *		analog range index, analog reference type, and flags.
+ * @unused:	Reserved for future use.
+ *
+ * This is used with the %COMEDI_INSN ioctl, and indirectly with the
+ * %COMEDI_INSNLIST ioctl.
+ */
+struct comedi_insn {
+	unsigned int insn;
+	unsigned int n;
+	unsigned int __user *data;
+	unsigned int subdev;
+	unsigned int chanspec;
+	unsigned int unused[3];
+};
+
+/**
+ * struct comedi_insnlist - list of COMEDI instructions
+ * @n_insns:	Number of COMEDI instructions.
+ * @insns:	Pointer to array COMEDI instructions.
+ *
+ * This is used with the %COMEDI_INSNLIST ioctl.
+ */
+struct comedi_insnlist {
+	unsigned int n_insns;
+	struct comedi_insn __user *insns;
+};
+
+/**
+ * struct comedi_cmd - COMEDI asynchronous acquisition command details
+ * @subdev:		Subdevice index.
+ * @flags:		Command flags (%CMDF_xxx).
+ * @start_src:		"Start acquisition" trigger source (%TRIG_xxx).
+ * @start_arg:		"Start acquisition" trigger argument.
+ * @scan_begin_src:	"Scan begin" trigger source.
+ * @scan_begin_arg:	"Scan begin" trigger argument.
+ * @convert_src:	"Convert" trigger source.
+ * @convert_arg:	"Convert" trigger argument.
+ * @scan_end_src:	"Scan end" trigger source.
+ * @scan_end_arg:	"Scan end" trigger argument.
+ * @stop_src:		"Stop acquisition" trigger source.
+ * @stop_arg:		"Stop acquisition" trigger argument.
+ * @chanlist:		Pointer to array of "chanspec" values, containing a
+ *			sequence of channel numbers packed with analog range
+ *			index, etc.
+ * @chanlist_len:	Number of channels in sequence.
+ * @data:		Pointer to miscellaneous set-up data (not used).
+ * @data_len:		Length of miscellaneous set-up data.
+ *
+ * This is used with the %COMEDI_CMD or %COMEDI_CMDTEST ioctl to set-up
+ * or validate an asynchronous acquisition command.  The ioctl may modify
+ * the &struct comedi_cmd and copy it back to the caller.
+ *
+ * Optional command @flags values that can be ORed together...
+ *
+ * %CMDF_BOGUS - makes %COMEDI_CMD ioctl return error %EAGAIN instead of
+ * starting the command.
+ *
+ * %CMDF_PRIORITY - requests "hard real-time" processing (which is not
+ * supported in this version of COMEDI).
+ *
+ * %CMDF_WAKE_EOS - requests the command makes data available for reading
+ * after every "scan" period.
+ *
+ * %CMDF_WRITE - marks the command as being in the "write" (to device)
+ * direction.  This does not need to be specified by the caller unless the
+ * subdevice supports commands in either direction.
+ *
+ * %CMDF_RAWDATA - prevents the command from "munging" the data between the
+ * COMEDI sample format and the raw hardware sample format.
+ *
+ * %CMDF_ROUND_NEAREST - requests timing periods to be rounded to nearest
+ * supported values.
+ *
+ * %CMDF_ROUND_DOWN - requests timing periods to be rounded down to supported
+ * values (frequencies rounded up).
+ *
+ * %CMDF_ROUND_UP - requests timing periods to be rounded up to supported
+ * values (frequencies rounded down).
+ *
+ * Trigger source values for @start_src, @scan_begin_src, @convert_src,
+ * @scan_end_src, and @stop_src...
+ *
+ * %TRIG_ANY - "all ones" value used to test which trigger sources are
+ * supported.
+ *
+ * %TRIG_INVALID - "all zeroes" value used to indicate that all requested
+ * trigger sources are invalid.
+ *
+ * %TRIG_NONE - never trigger (often used as a @stop_src value).
+ *
+ * %TRIG_NOW - trigger after '_arg' nanoseconds.
+ *
+ * %TRIG_FOLLOW - trigger follows another event.
+ *
+ * %TRIG_TIMER - trigger every '_arg' nanoseconds.
+ *
+ * %TRIG_COUNT - trigger when count '_arg' is reached.
+ *
+ * %TRIG_EXT - trigger on external signal specified by '_arg'.
+ *
+ * %TRIG_INT - trigger on internal, software trigger specified by '_arg'.
+ *
+ * %TRIG_OTHER - trigger on other, driver-defined signal specified by '_arg'.
+ */
+struct comedi_cmd {
+	unsigned int subdev;
+	unsigned int flags;
+
+	unsigned int start_src;
+	unsigned int start_arg;
+
+	unsigned int scan_begin_src;
+	unsigned int scan_begin_arg;
+
+	unsigned int convert_src;
+	unsigned int convert_arg;
+
+	unsigned int scan_end_src;
+	unsigned int scan_end_arg;
+
+	unsigned int stop_src;
+	unsigned int stop_arg;
+
+	unsigned int *chanlist;
+	unsigned int chanlist_len;
+
+	short __user *data;
+	unsigned int data_len;
+};
+
+/**
+ * struct comedi_chaninfo - used to retrieve per-channel information
+ * @subdev:		Subdevice index.
+ * @maxdata_list:	Optional pointer to per-channel maximum data values.
+ * @flaglist:		Optional pointer to per-channel flags.
+ * @rangelist:		Optional pointer to per-channel range types.
+ * @unused:		Reserved for future use.
+ *
+ * This is used with the %COMEDI_CHANINFO ioctl to get per-channel information
+ * for the subdevice.  Use of this requires knowledge of the number of channels
+ * and subdevice flags obtained using the %COMEDI_SUBDINFO ioctl.
+ *
+ * The @maxdata_list member must be %NULL unless the %SDF_MAXDATA subdevice
+ * flag is set.  The @flaglist member must be %NULL unless the %SDF_FLAGS
+ * subdevice flag is set.  The @rangelist member must be %NULL unless the
+ * %SDF_RANGETYPE subdevice flag is set.  Otherwise, the arrays they point to
+ * must be at least as long as the number of channels.
+ */
+struct comedi_chaninfo {
+	unsigned int subdev;
+	unsigned int __user *maxdata_list;
+	unsigned int __user *flaglist;
+	unsigned int __user *rangelist;
+	unsigned int unused[4];
+};
+
+/**
+ * struct comedi_rangeinfo - used to retrieve the range table for a channel
+ * @range_type:		Encodes subdevice index (bits 27:24), channel index
+ *			(bits 23:16) and range table length (bits 15:0).
+ * @range_ptr:		Pointer to array of @struct comedi_krange to be filled
+ *			in with the range table for the channel or subdevice.
+ *
+ * This is used with the %COMEDI_RANGEINFO ioctl to retrieve the range table
+ * for a specific channel (if the subdevice has the %SDF_RANGETYPE flag set to
+ * indicate that the range table depends on the channel), or for the subdevice
+ * as a whole (if the %SDF_RANGETYPE flag is clear, indicating the range table
+ * is shared by all channels).
+ *
+ * The @range_type value is an input to the ioctl and comes from a previous
+ * use of the %COMEDI_SUBDINFO ioctl (if the %SDF_RANGETYPE flag is clear),
+ * or the %COMEDI_CHANINFO ioctl (if the %SDF_RANGETYPE flag is set).
+ */
+struct comedi_rangeinfo {
+	unsigned int range_type;
+	void __user *range_ptr;
+};
+
+/**
+ * struct comedi_krange - describes a range in a range table
+ * @min:	Minimum value in millionths (1e-6) of a unit.
+ * @max:	Maximum value in millionths (1e-6) of a unit.
+ * @flags:	Indicates the units (in bits 7:0) OR'ed with optional flags.
+ *
+ * A range table is associated with a single channel, or with all channels in a
+ * subdevice, and a list of one or more ranges.  A %struct comedi_krange
+ * describes the physical range of units for one of those ranges.  Sample
+ * values in COMEDI are unsigned from %0 up to some 'maxdata' value.  The
+ * mapping from sample values to physical units is assumed to be nomimally
+ * linear (for the purpose of describing the range), with sample value %0
+ * mapping to @min, and the 'maxdata' sample value mapping to @max.
+ *
+ * The currently defined units are %UNIT_volt (%0), %UNIT_mA (%1), and
+ * %UNIT_none (%2).  The @min and @max values are the physical range multiplied
+ * by 1e6, so a @max value of %1000000 (with %UNIT_volt) represents a maximal
+ * value of 1 volt.
+ *
+ * The only defined flag value is %RF_EXTERNAL (%0x100), indicating that the
+ * range needs to be multiplied by an external reference.
+ */
+struct comedi_krange {
+	int min;
+	int max;
+	unsigned int flags;
+};
+
+/**
+ * struct comedi_subdinfo - used to retrieve information about a subdevice
+ * @type:		Type of subdevice from &enum comedi_subdevice_type.
+ * @n_chan:		Number of channels the subdevice supports.
+ * @subd_flags:		A mixture of static and dynamic flags describing
+ *			aspects of the subdevice and its current state.
+ * @timer_type:		Timer type.  Always set to %5 ("nanosecond timer").
+ * @len_chanlist:	Maximum length of a channel list if the subdevice
+ *			supports asynchronous acquisition commands.
+ * @maxdata:		Maximum sample value for all channels if the
+ *			%SDF_MAXDATA subdevice flag is clear.
+ * @flags:		Channel flags for all channels if the %SDF_FLAGS
+ *			subdevice flag is clear.
+ * @range_type:		The range type for all channels if the %SDF_RANGETYPE
+ *			subdevice flag is clear.  Encodes the subdevice index
+ *			(bits 27:24), a dummy channel index %0 (bits 23:16),
+ *			and the range table length (bits 15:0).
+ * @settling_time_0:	Not used.
+ * @insn_bits_support:	Set to %COMEDI_SUPPORTED if the subdevice supports the
+ *			%INSN_BITS instruction, or to %COMEDI_UNSUPPORTED if it
+ *			does not.
+ * @unused:		Reserved for future use.
+ *
+ * This is used with the %COMEDI_SUBDINFO ioctl which copies an array of
+ * &struct comedi_subdinfo back to user space, with one element per subdevice.
+ * Use of this requires knowledge of the number of subdevices obtained from
+ * the %COMEDI_DEVINFO ioctl.
+ *
+ * These are the @subd_flags values that may be ORed together...
+ *
+ * %SDF_BUSY - the subdevice is busy processing an asynchronous command or a
+ * synchronous instruction.
+ *
+ * %SDF_BUSY_OWNER - the subdevice is busy processing an asynchronous
+ * acquisition command started on the current file object (the file object
+ * issuing the %COMEDI_SUBDINFO ioctl).
+ *
+ * %SDF_LOCKED - the subdevice is locked by a %COMEDI_LOCK ioctl.
+ *
+ * %SDF_LOCK_OWNER - the subdevice is locked by a %COMEDI_LOCK ioctl from the
+ * current file object.
+ *
+ * %SDF_MAXDATA - maximum sample values are channel-specific.
+ *
+ * %SDF_FLAGS - channel flags are channel-specific.
+ *
+ * %SDF_RANGETYPE - range types are channel-specific.
+ *
+ * %SDF_PWM_COUNTER - PWM can switch off automatically.
+ *
+ * %SDF_PWM_HBRIDGE - or PWM is signed (H-bridge).
+ *
+ * %SDF_CMD - the subdevice supports asynchronous commands.
+ *
+ * %SDF_SOFT_CALIBRATED - the subdevice uses software calibration.
+ *
+ * %SDF_CMD_WRITE - the subdevice supports asynchronous commands in the output
+ * ("write") direction.
+ *
+ * %SDF_CMD_READ - the subdevice supports asynchronous commands in the input
+ * ("read") direction.
+ *
+ * %SDF_READABLE - the subdevice is readable (e.g. analog input).
+ *
+ * %SDF_WRITABLE (aliased as %SDF_WRITEABLE) - the subdevice is writable (e.g.
+ * analog output).
+ *
+ * %SDF_INTERNAL - the subdevice has no externally visible lines.
+ *
+ * %SDF_GROUND - the subdevice can use ground as an analog reference.
+ *
+ * %SDF_COMMON - the subdevice can use a common analog reference.
+ *