staging:iio: allow channels to be set up using a table of iio_channel…

…_spec structures.

V8: Add missing address in IIO_CHAN macro. Spotted by Michael Hennerich.
V7: Document additions to iio_dev structure.
V6: Fixup the docs for iio_chan_spec structure.
V5: Actually have the macro handle the _input type channels (oops)
V4: Add ability to do, _input and modified channel naming in a coherent fashion.
    Scrap all the messy IIO_CHAN_* macros and move to only one.

V3: Added more types - intensity and light.

V2: Various fixes - some thanks to Arnd.
    Bug fix for unregistering of event attr group
    Changed iio_read_channel_info to have two part value - use for
    raw value read as well.
    constify the channelspec structures
    raw write support for calibbias and similar
    Additional strings for buidling attribute names.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/chrdev.h

@@ -91,6 +91,9 @@ struct iio_event_interface {
 	void					*private;
 	char					_name[35];
 	char					_attrname[20];
+
+	struct list_head event_attr_list;
+	struct list_head dev_attr_list;
 };
 
 /**

drivers/staging/iio/iio.h

@@ -26,6 +26,161 @@
 
 struct iio_dev;
 
+/* naughty temporary hack to match these against the event version
+   - need to flattern these together */
+enum iio_chan_type {
+	/* Need this here for now to support buffer events
+	 * set to 0  to avoid changes to ring_generic.c */
+	IIO_BUFFER = 0,
+
+	/* real channel types */
+	IIO_IN,
+	IIO_ACCEL,
+	IIO_IN_DIFF,
+	IIO_GYRO,
+	IIO_MAGN,
+	IIO_LIGHT,
+	IIO_INTENSITY,
+	IIO_PROXIMITY,
+	IIO_TEMP,
+	IIO_INCLI,
+	IIO_ROT,
+	IIO_ANGL,
+	IIO_TIMESTAMP,
+};
+
+#define IIO_MOD_X			0
+#define IIO_MOD_LIGHT_BOTH		0
+#define IIO_MOD_Y			1
+#define IIO_MOD_LIGHT_IR		1
+#define IIO_MOD_Z			2
+#define IIO_MOD_X_AND_Y			3
+#define IIO_MOD_X_ANX_Z			4
+#define IIO_MOD_Y_AND_Z			5
+#define IIO_MOD_X_AND_Y_AND_Z		6
+#define IIO_MOD_X_OR_Y			7
+#define IIO_MOD_X_OR_Z			8
+#define IIO_MOD_Y_OR_Z			9
+#define IIO_MOD_X_OR_Y_OR_Z		10
+
+/* Could add the raw attributes as well - allowing buffer only devices */
+enum iio_chan_info_enum {
+	IIO_CHAN_INFO_SCALE_SHARED,
+	IIO_CHAN_INFO_SCALE_SEPARATE,
+	IIO_CHAN_INFO_OFFSET_SHARED,
+	IIO_CHAN_INFO_OFFSET_SEPARATE,
+	IIO_CHAN_INFO_CALIBSCALE_SHARED,
+	IIO_CHAN_INFO_CALIBSCALE_SEPARATE,
+	IIO_CHAN_INFO_CALIBBIAS_SHARED,
+	IIO_CHAN_INFO_CALIBBIAS_SEPARATE
+};
+
+/**
+ * struct iio_chan_spec - specification of a single channel
+ * @type:		What type of measurement is the channel making.
+ * @channel:		What number or name do we wish to asign the channel.
+ * @channel2:		If there is a second number for a differential
+ *			channel then this is it. If modified is set then the
+ *			value here specifies the modifier.
+ * @address:		Driver specific identifier.
+ * @scan_index:	Monotonic index to give ordering in scans when read
+ *			from a buffer.
+ * @scan_type:		Sign:		's' or 'u' to specify signed or unsigned
+ *			realbits:	Number of valid bits of data
+ *			storage_bits:	Realbits + padding
+ *			shift:		Shift right by this before masking out
+ *					realbits.
+ * @info_mask:		What information is to be exported about this channel.
+ *			This includes calibbias, scale etc.
+ * @event_mask:	What events can this channel produce.
+ * @extend_name:	Allows labeling of channel attributes with an
+ *			informative name. Note this has no effect codes etc,
+ *			unlike modifiers.
+ * @processed_val:	Flag to specify the data access attribute should be
+ *			*_input rather than *_raw.
+ * @modified:		Does a modifier apply to this channel. What these are
+ *			depends on the channel type.  Modifier is set in
+ *			channel2. Examples are IIO_MOD_X for axial sensors about
+ *			the 'x' axis.
+ * @indexed:		Specify the channel has a numerical index. If not,
+ *			the value in channel will be suppressed for attribute
+ *			but not for event codes. Typically set it to 0 when
+ *			the index is false.
+ * @shared_handler:	Single handler for the events registered.
+ */
+struct iio_chan_spec {
+	enum iio_chan_type	type;
+	int			channel;
+	int			channel2;
+	unsigned long		address;
+	int			scan_index;
+	struct {
+		char	sign;
+		u8	realbits;
+		u8	storagebits;
+		u8	shift;
+	} scan_type;
+	const long		info_mask;
+	const long		event_mask;
+	const char		*extend_name;
+	unsigned		processed_val:1;
+	unsigned		modified:1;
+	unsigned		indexed:1;
+	/* TODO: investigate pushing shared event handling out to
+	 * the drivers */
+	struct iio_event_handler_list *shared_handler;
+};
+/* Meant for internal use only */
+void __iio_device_attr_deinit(struct device_attribute *dev_attr);
+int __iio_device_attr_init(struct device_attribute *dev_attr,
+			   const char *postfix,
+			   struct iio_chan_spec const *chan,
+			   ssize_t (*readfunc)(struct device *dev,
+					       struct device_attribute *attr,
+					       char *buf),
+			   ssize_t (*writefunc)(struct device *dev,
+						struct device_attribute *attr,
+						const char *buf,
+						size_t len),
+			   bool generic);
+#define IIO_ST(si, rb, sb, sh)						\
+	{ .sign = si, .realbits = rb, .storagebits = sb, .shift = sh }
+
+#define IIO_CHAN(_type, _mod, _indexed, _proc, _name, _chan, _chan2,	\
+		 _inf_mask, _address, _si, _stype, _event_mask,		\
+		 _handler)						\
+	{ .type = _type,						\
+	  .modified = _mod,						\
+	  .indexed = _indexed,						\
+	  .processed_val = _proc,					\
+	  .extend_name = _name,						\
+	  .channel = _chan,						\
+	  .channel2 = _chan2,						\
+	  .info_mask = _inf_mask,					\
+	  .address = _address,						\
+	  .scan_index = _si,						\
+	  .scan_type = _stype,						\
+	  .event_mask = _event_mask,					\
+	  .shared_handler = _handler }
+
+#define IIO_CHAN_SOFT_TIMESTAMP(_si)					\
+	{ .type = IIO_TIMESTAMP, .channel = -1,				\
+			.scan_index = _si, .scan_type = IIO_ST('s', 64, 64, 0) }
+
+int __iio_add_chan_devattr(const char *postfix,
+			   const char *group,
+			   struct iio_chan_spec const *chan,
+			   ssize_t (*func)(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf),
+			   ssize_t (*writefunc)(struct device *dev,
+						struct device_attribute *attr,
+						const char *buf,
+						size_t len),
+			   int mask,
+			   bool generic,
+			   struct device *dev,
+			   struct list_head *attr_list);
 /**
  * iio_get_time_ns() - utility function to get a time stamp for events etc
  **/
@@ -70,7 +225,8 @@ void iio_remove_event_from_list(struct iio_event_handler_list *el,
 
 /* Vast majority of this is set by the industrialio subsystem on a
  * call to iio_device_register. */
-
+#define IIO_VAL_INT 1
+#define IIO_VAL_INT_PLUS_MICRO 2
 /**
  * struct iio_dev - industrial I/O device
  * @id:			[INTERN] used to identify device internally
@@ -93,6 +249,24 @@ void iio_remove_event_from_list(struct iio_event_handler_list *el,
  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
  * @trig:		[INTERN] current device trigger (ring buffer modes)
  * @pollfunc:		[DRIVER] function run on trigger being received
+ * @channels:		[DRIVER] channel specification structure table
+ * @num_channels:	[DRIVER] number of chanels specified in @channels.
+ * @channel_attr_list:	[INTERN] keep track of automatically created channel
+ *			attributes.
+ * @name:		[DRIVER] name of the device.
+ * @read_raw:		[DRIVER] function to request a value from the device.
+ *			mask specifies which value. Note 0 means a reading of
+ *			the channel in question.  Return value will specify the
+ *			type of value returned by the device. val and val2 will
+ *			contain the elements making up the returned value.
+ * @write_raw:		[DRIVER] function to write a value to the device.
+ *			Parameters are the same as for read_raw.
+ * @read_event_config:	[DRIVER] find out if the event is enabled.
+ * @write_event_config:	[DRIVER] set if the event is enabled.
+ * @read_event_value:	[DRIVER] read a value associated with the event. Meaning
+ *			is event dependant. event_code specifies which event.
+ * @write_event_value:	[DRIVER] write the value associate with the event.
+ *			Meaning is event dependent.
  **/
 struct iio_dev {
 	int				id;
@@ -116,6 +290,38 @@ struct iio_dev {
 	u32				*available_scan_masks;
 	struct iio_trigger		*trig;
 	struct iio_poll_func		*pollfunc;
+
+	struct iio_chan_spec const *channels;
+	int num_channels;
+	struct list_head channel_attr_list;
+
+	char *name; /*device name - IMPLEMENT */
+	int (*read_raw)(struct iio_dev *indio_dev,
+			struct iio_chan_spec const *chan,
+			int *val,
+			int *val2,
+			long mask);
+
+	int (*write_raw)(struct iio_dev *indio_dev,
+			 struct iio_chan_spec const *chan,
+			 int val,
+			 int val2,
+			 long mask);
+
+	int (*read_event_config)(struct iio_dev *indio_dev,
+				 int event_code);
+
+	int (*write_event_config)(struct iio_dev *indio_dev,
+				  int event_code,
+				  struct iio_event_handler_list *listel,
+				  int state);
+
+	int (*read_event_value)(struct iio_dev *indio_dev,
+				int event_code,
+				int *val);
+	int (*write_event_value)(struct iio_dev *indio_dev,
+				 int event_code,
+				 int val);
 };
 
 /**