Staging: IIO: core support for device registration and management

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

drivers/staging/Kconfig

@@ -137,5 +137,7 @@ source "drivers/staging/rar/Kconfig"
 
 source "drivers/staging/sep/Kconfig"
 
+source "drivers/staging/iio/Kconfig"
+
 endif # !STAGING_EXCLUDE_BUILD
 endif # STAGING

drivers/staging/Makefile

@@ -50,3 +50,4 @@ obj-$(CONFIG_HYPERV)		+= hv/
 obj-$(CONFIG_VME_BUS)		+= vme/
 obj-$(CONFIG_RAR_REGISTER)	+= rar/
 obj-$(CONFIG_DX_SEP)		+= sep/
+obj-$(CONFIG_IIO)		+= iio/

drivers/staging/iio/Kconfig

+#
+# Industrial I/O subsytem configuration
+#
+
+menuconfig IIO
+	tristate "Industrial I/O support"
+	---help---
+	  The industrial I/O subsystem provides a unified framework for
+	  drivers for many different types of embedded sensors using a
+	  number of different physical interfaces (i2c, spi etc). See
+	  Documentation/industrialio for more information.

drivers/staging/iio/Makefile

+#
+# Makefile for the industrial I/O core.
+#
+
+obj-$(CONFIG_IIO) += industrialio.o
+industrialio-y := industrialio-core.o

drivers/staging/iio/chrdev.h

+/* The industrial I/O core - character device related
+ *
+ * Copyright (c) 2008 Jonathan Cameron
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef _IIO_CHRDEV_H_
+#define _IIO_CHRDEV_H_
+struct iio_dev;
+
+/**
+ * struct iio_handler - Structure used to specify file operations
+ *			for a particular chrdev
+ * @chrdev:	character device structure
+ * @id:		the location in the handler table - used for deallocation.
+ * @flags:	file operations related flags including busy flag.
+ * @private:	handler specific data used by the fileops registered with
+ *		the chrdev.
+ */
+struct iio_handler {
+	struct cdev	chrdev;
+	int		id;
+	unsigned long	flags;
+	void		*private;
+};
+
+#define iio_cdev_to_handler(cd)				\
+	container_of(cd, struct iio_handler, chrdev)
+
+/**
+ * struct iio_event_data - The actual event being pushed to userspace
+ * @id:		event identifier
+ * @timestamp:	best estimate of time of event occurance (often from
+ *		the interrupt handler)
+ */
+struct iio_event_data {
+	int	id;
+	s64	timestamp;
+};
+
+/**
+ * struct iio_detected_event_list - list element for events that have occured
+ * @list:		linked list header
+ * @ev:			the event itself
+ * @shared_pointer:	used when the event is shared - i.e. can be escallated
+ *			on demand (eg ring buffer 50%->100% full)
+ */
+struct iio_detected_event_list {
+	struct list_head		list;
+	struct iio_event_data		ev;
+	struct iio_shared_ev_pointer	*shared_pointer;
+};
+/**
+ * struct iio_shared_ev_pointer - allows shared events to identify if currently
+ *				in the detected event list
+ * @ev_p:	pointer to detected event list element (null if not in list)
+ * @lock:	protect this element to prevent simultaneous edit and remove
+ */
+struct iio_shared_ev_pointer {
+	struct iio_detected_event_list	*ev_p;
+	spinlock_t			lock;
+};
+
+/**
+ * struct iio_event_interface - chrdev interface for an event line
+ * @dev:		device assocated with event interface
+ * @handler:		fileoperations and related control for the chrdev
+ * @wait:		wait queue to allow blocking reads of events
+ * @event_list_lock:	mutex to protect the list of detected events
+ * @det_events:		list of detected events
+ * @max_events:		maximum number of events before new ones are dropped
+ * @current_events:	number of events in detected list
+ * @id:			indentifier to allow the event interface to know which
+ *			physical line it corresponds to
+ * @owner:		ensure the driver module owns the file, not iio
+ * @private:		driver specific data
+ * @_name:		used internally to store the sysfs name for minor id
+ *			attribute
+ */
+struct iio_event_interface {
+	struct device				dev;
+	struct iio_handler			handler;
+	wait_queue_head_t			wait;
+	struct mutex				event_list_lock;
+	struct iio_detected_event_list		det_events;
+	int					max_events;
+	int					current_events;
+	int					id;
+	struct iio_chrdev_minor_attr		attr;
+	struct module				*owner;
+	void					*private;
+	char					_name[20];
+	char					_attrname[20];
+};
+
+/**
+ * struct iio_event_handler_list - element in list of handlers for events
+ * @list:		list header
+ * @refcount:		as the handler may be shared between multiple device
+ *			side events, reference counting ensures clean removal
+ * @exist_lock:		prevents race conditions related to refcount useage.
+ * @handler:		event handler function - called on event if this
+ *			event_handler is enabled.
+ *
+ * Each device has one list of these per interrupt line
+ **/
+struct iio_event_handler_list {
+	struct list_head	list;
+	int			refcount;
+	struct mutex		exist_lock;
+	int (*handler)(struct iio_dev *dev_info, int index, s64 timestamp,
+		       int no_test);
+};
+
+#endif

drivers/staging/iio/sysfs.h

+/* The industrial I/O core
+ *
+ *Copyright (c) 2008 Jonathan Cameron
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * General attributes
+ */
+
+#ifndef _INDUSTRIAL_IO_SYSFS_H_
+#define _INDUSTRIAL_IO_SYSFS_H_
+
+#include "iio.h"
+
+/**
+ * struct iio_event_attribute - event control attribute
+ * @dev_attr:	underlying device attribute
+ * @mask:	mask for the event when detecting
+ * @listel:	list header to allow addition to list of event handlers
+*/
+struct iio_event_attr {
+	struct device_attribute dev_attr;
+	int mask;
+	struct iio_event_handler_list *listel;
+};
+
+#define to_iio_event_attr(_dev_attr) \
+	container_of(_dev_attr, struct iio_event_attr, dev_attr)
+
+/**
+ * struct iio_chrdev_minor_attr - simple attribute to allow reading of chrdev
+ *				minor number
+ * @dev_attr:	underlying device attribute
+ * @minor:	the minor number
+ */
+struct iio_chrdev_minor_attr {
+	struct device_attribute dev_attr;
+	int minor;
+};
+
+void
+__init_iio_chrdev_minor_attr(struct iio_chrdev_minor_attr *minor_attr,
+			   const char *name,
+			   struct module *owner,
+			   int id);
+
+
+#define to_iio_chrdev_minor_attr(_dev_attr) \
+	container_of(_dev_attr, struct iio_chrdev_minor_attr, dev_attr);
+
+/**
+ * struct iio_dev_attr - iio specific device attribute
+ * @dev_attr:	underlying device attribute
+ * @address:	associated register address
+ */
+struct iio_dev_attr {
+	struct device_attribute dev_attr;
+	int address;
+	int val2;
+};
+
+#define to_iio_dev_attr(_dev_attr)				\
+	container_of(_dev_attr, struct iio_dev_attr, dev_attr)
+
+ssize_t iio_read_const_attr(struct device *dev,
+			    struct device_attribute *attr,
+			    char *len);
+
+/**
+ * struct iio_const_attr - constant device specific attribute
+ *                         often used for things like available modes
+ */
+struct iio_const_attr {
+	const char *string;
+	struct device_attribute dev_attr;
+};
+
+#define to_iio_const_attr(_dev_attr) \
+	container_of(_dev_attr, struct iio_const_attr, dev_attr)
+
+/* Some attributes will be hard coded (device dependant) and not require an
+   address, in these cases pass a negative */
+#define IIO_ATTR(_name, _mode, _show, _store, _addr)		\
+	{ .dev_attr = __ATTR(_name, _mode, _show, _store),	\
+	  .address = _addr }
+
+#define IIO_ATTR_2(_name, _mode, _show, _store, _addr, _val2)	\
+	{ .dev_attr = __ATTR(_name, _mode, _show, _store),	\
+			.address = _addr,			\
+			.val2 = _val2 }
+
+#define IIO_DEVICE_ATTR(_name, _mode, _show, _store, _addr)	\
+	struct iio_dev_attr iio_dev_attr_##_name		\
+	= IIO_ATTR(_name, _mode, _show, _store, _addr)
+
+
+#define IIO_DEVICE_ATTR_2(_name, _mode, _show, _store, _addr, _val2)	\
+	struct iio_dev_attr iio_dev_attr_##_name			\
+	= IIO_ATTR_2(_name, _mode, _show, _store, _addr, _val2)
+
+#define IIO_CONST_ATTR(_name, _string)					\
+	struct iio_const_attr iio_const_attr_##_name			\
+	= { .string = _string,						\
+	    .dev_attr = __ATTR(_name, S_IRUGO, iio_read_const_attr, NULL)}
+
+/* Generic attributes of onetype or another */
+
+/**
+ * IIO_DEV_ATTR_REG: revision number for the device
+ *
+ * Very much device dependent.
+ **/
+#define IIO_DEV_ATTR_REV(_show)			\
+	IIO_DEVICE_ATTR(revision, S_IRUGO, _show, NULL, 0)
+/**
+ * IIO_DEV_ATTR_NAME: chip type dependant identifier
+ **/
+#define IIO_DEV_ATTR_NAME(_show)				\
+	IIO_DEVICE_ATTR(name, S_IRUGO, _show, NULL, 0)
+
+/**
+ * IIO_DEV_ATTR_SAMP_FREQ: sets any internal clock frequency
+ **/
+#define IIO_DEV_ATTR_SAMP_FREQ(_mode, _show, _store)			\
+	IIO_DEVICE_ATTR(sampling_frequency, _mode, _show, _store, 0)
+
+/**
+ * IIO_DEV_ATTR_AVAIL_SAMP_FREQ: list available sampling frequencies.
+ *
+ * May be mode dependant on some devices
+ **/
+#define IIO_DEV_ATTR_AVAIL_SAMP_FREQ(_show)				\
+	IIO_DEVICE_ATTR(available_sampling_frequency, S_IRUGO, _show, NULL, 0)
+
+/**
+ * IIO_DEV_ATTR_CONST_AVAIL_SAMP_FREQ: list available sampling frequencies.
+ *
+ * Constant version
+ **/
+#define IIO_CONST_ATTR_AVAIL_SAMP_FREQ(_string)	\
+	IIO_CONST_ATTR(available_sampling_frequency, _string)
+/**
+ * IIO_DEV_ATTR_SCAN_MODE: select a scan mode
+ *
+ * This is used when only certain combinations of inputs may be read in one
+ * scan.
+ **/
+#define IIO_DEV_ATTR_SCAN_MODE(_mode, _show, _store)		\
+	IIO_DEVICE_ATTR(scan_mode, _mode, _show, _store, 0)
+/**
+ * IIO_DEV_ATTR_AVAIL_SCAN_MODES: list available scan modes
+ **/
+#define IIO_DEV_ATTR_AVAIL_SCAN_MODES(_show)				\
+	IIO_DEVICE_ATTR(available_scan_modes, S_IRUGO, _show, NULL, 0)
+
+/**
+ * IIO_DEV_ATTR_SCAN: result of scan of multiple channels
+ **/
+#define IIO_DEV_ATTR_SCAN(_show)		\
+	IIO_DEVICE_ATTR(scan, S_IRUGO, _show, NULL, 0);
+
+/**
+ * IIO_DEV_ATTR_INPUT: direct read of a single input channel
+ **/
+#define IIO_DEV_ATTR_INPUT(_number, _show)				\
+	IIO_DEVICE_ATTR(in##_number, S_IRUGO, _show, NULL, _number)
+
+
+/**
+ * IIO_DEV_ATTR_SW_RING_ENABLE: enable software ring buffer
+ *
+ * Success may be dependant on attachment of trigger previously
+ **/
+#define IIO_DEV_ATTR_SW_RING_ENABLE(_show, _store)			\
+	IIO_DEVICE_ATTR(sw_ring_enable, S_IRUGO | S_IWUSR, _show, _store, 0)
+
+/**
+ * IIO_DEV_ATTR_HW_RING_ENABLE: enable hardware ring buffer
+ *
+ * This is a different attribute from the software one as one can invision
+ * schemes where a combination of the two may be used.
+ **/
+#define IIO_DEV_ATTR_HW_RING_ENABLE(_show, _store)			\
+	IIO_DEVICE_ATTR(hw_ring_enable, S_IRUGO | S_IWUSR, _show, _store, 0)
+
+/**
+ * IIO_DEV_ATTR_BPSE: set number of bits per scan element
+ **/
+#define IIO_DEV_ATTR_BPSE(_mode, _show, _store)		\
+	IIO_DEVICE_ATTR(bpse, _mode, _show, _store, 0)
+
+/**
+ * IIO_DEV_ATTR_BPSE_AVAILABLE: no of bits per scan element supported
+ **/
+#define IIO_DEV_ATTR_BPSE_AVAILABLE(_show)				\
+	IIO_DEVICE_ATTR(bpse_available, S_IRUGO, _show, NULL, 0)
+
+/**
+ * IIO_DEV_ATTR_TEMP: many sensors have auxiliary temperature sensors
+ **/
+#define IIO_DEV_ATTR_TEMP(_show)			\
+	IIO_DEVICE_ATTR(temp, S_IRUGO, _show, NULL, 0)
+/**
+ * IIO_EVENT_SH: generic shared event handler
+ *
+ * This is used in cases where more than one event may result from a single
+ * handler.  Often the case that some alarm register must be read and multiple
+ * alarms may have been triggered.
+ **/
+#define IIO_EVENT_SH(_name, _handler)					\
+	static struct iio_event_handler_list				\
+	iio_event_##_name = {						\
+		.handler = _handler,					\
+		.refcount = 0,						\
+		.exist_lock = __MUTEX_INITIALIZER(iio_event_##_name	\
+						  .exist_lock),		\
+		.list = {						\
+			.next = &iio_event_##_name.list,		\
+			.prev = &iio_event_##_name.list,		\
+		},							\
+	};
+/**
+ * IIO_EVENT_ATTR_SH: generic shared event attribute
+ *
+ * An attribute with an associated IIO_EVENT_SH
+ **/
+#define IIO_EVENT_ATTR_SH(_name, _ev_list, _show, _store, _mask)	\
+	static struct iio_event_attr					\
+	iio_event_attr_##_name						\
+	= { .dev_attr = __ATTR(_name, S_IRUGO | S_IWUSR,		\
+			       _show, _store),				\
+	    .mask = _mask,						\
+	    .listel = &_ev_list };
+
+/**
+ * IIO_EVENT_ATTR: non shared event attribute
+ **/
+#define IIO_EVENT_ATTR(_name, _show, _store, _mask, _handler)		\
+	static struct iio_event_handler_list				\
+	iio_event_##_name = {						\
+		.handler = _handler,					\
+	};								\
+	static struct							\
+	iio_event_attr							\
+	iio_event_attr_##_name						\
+	= { .dev_attr = __ATTR(_name, S_IRUGO | S_IWUSR,		\
+			       _show, _store),				\
+	    .mask = _mask,						\
+	    .listel = &iio_event_##_name };				\
+
+/**
+ * IIO_EVENT_ATTR_DATA_RDY: event driven by data ready signal
+ *
+ * Not typically implemented in devices where full triggering support
+ * has been implemented
+ **/
+#define IIO_EVENT_ATTR_DATA_RDY(_show, _store, _mask, _handler) \
+	IIO_EVENT_ATTR(data_rdy, _show, _store, _mask, _handler)
+
+#define IIO_EVENT_CODE_DATA_RDY		100
+#define IIO_EVENT_CODE_RING_BASE	200
+#define IIO_EVENT_CODE_ACCEL_BASE	300
+#define IIO_EVENT_CODE_GYRO_BASE	400
+#define IIO_EVENT_CODE_ADC_BASE		500
+#define IIO_EVENT_CODE_MISC_BASE	600
+
+#define IIO_EVENT_CODE_DEVICE_SPECIFIC	1000
+
+/**
+ * IIO_EVENT_ATTR_RING_50_FULL: ring buffer event to indicate 50% full
+ **/
+#define IIO_EVENT_ATTR_RING_50_FULL(_show, _store, _mask, _handler)	\
+	IIO_EVENT_ATTR(ring_50_full, _show, _store, _mask, _handler)
+
+/**
+ * IIO_EVENT_ATTR_RING_50_FULL_SH: shared ring event to indicate 50% full
+ **/
+#define IIO_EVENT_ATTR_RING_50_FULL_SH(_evlist, _show, _store, _mask)	\
+	IIO_EVENT_ATTR_SH(ring_50_full, _evlist, _show, _store, _mask)
+
+/**
+ * IIO_EVENT_ATTR_RING_75_FULL_SH: shared ring event to indicate 75% full
+ **/
+#define IIO_EVENT_ATTR_RING_75_FULL_SH(_evlist, _show, _store, _mask)	\
+	IIO_EVENT_ATTR_SH(ring_75_full, _evlist, _show, _store, _mask)
+
+#define IIO_EVENT_CODE_RING_50_FULL	IIO_EVENT_CODE_RING_BASE
+#define IIO_EVENT_CODE_RING_75_FULL	(IIO_EVENT_CODE_RING_BASE + 1)
+#define IIO_EVENT_CODE_RING_100_FULL	(IIO_EVENT_CODE_RING_BASE + 2)
+
+#endif /* _INDUSTRIAL_IO_SYSFS_H_ */

drivers/staging/iio/trigger_consumer.h

+
+/* The industrial I/O core, trigger consumer handling functions
+ *
+ * Copyright (c) 2008 Jonathan Cameron
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+/**
+ * iio_device_register_trigger_consumer() - set up an iio_dev to use triggers.
+ * @dev_info: iio_dev associated with the device that will consume the trigger
+ **/
+int iio_device_register_trigger_consumer(struct iio_dev *dev_info)
+{
+	return 0;
+};
+/**
+ * iio_device_unregister_trigger_consumer() - reverse the registration process
+. * @dev_info: iio_dev associated with the device that consumed the trigger
+ **/
+int iio_device_unregister_trigger_consumer(struct iio_dev *dev_info)
+{
+	return 0;
+};