[net-next-2.6.git] / drivers / staging / iio / industrialio-ring.c

/* 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.
 *
 * Handling of ring allocation / resizing.
 *
 *
 * Things to look at here.
 * - Better memory allocation techniques?
 * - Alternative access techniques?
 */
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/cdev.h>
#include <linux/slab.h>

#include "iio.h"
#include "ring_generic.h"

int iio_push_ring_event(struct iio_ring_buffer *ring_buf,
		       int event_code,
		       s64 timestamp)
{
	return __iio_push_event(&ring_buf->ev_int,
			       event_code,
			       timestamp,
			       &ring_buf->shared_ev_pointer);
}
EXPORT_SYMBOL(iio_push_ring_event);

int iio_push_or_escallate_ring_event(struct iio_ring_buffer *ring_buf,
				    int event_code,
				    s64 timestamp)
{
	if (ring_buf->shared_ev_pointer.ev_p)
		__iio_change_event(ring_buf->shared_ev_pointer.ev_p,
				   event_code,
				   timestamp);
	else
		return iio_push_ring_event(ring_buf,
					  event_code,
					  timestamp);
	return 0;
}
EXPORT_SYMBOL(iio_push_or_escallate_ring_event);

/**
 * iio_ring_open() - chrdev file open for ring buffer access
 *
 * This function relies on all ring buffer implementations having an
 * iio_ring_buffer as their first element.
 **/
static int iio_ring_open(struct inode *inode, struct file *filp)
{
	struct iio_handler *hand
		= container_of(inode->i_cdev, struct iio_handler, chrdev);
	struct iio_ring_buffer *rb = hand->private;

	filp->private_data = hand->private;
	if (rb->access.mark_in_use)
		rb->access.mark_in_use(rb);

	return 0;
}

/**
 * iio_ring_release() - chrdev file close ring buffer access
 *
 * This function relies on all ring buffer implementations having an
 * iio_ring_buffer as their first element.
 **/
static int iio_ring_release(struct inode *inode, struct file *filp)
{
	struct cdev *cd = inode->i_cdev;
	struct iio_handler *hand = iio_cdev_to_handler(cd);
	struct iio_ring_buffer *rb = hand->private;

	clear_bit(IIO_BUSY_BIT_POS, &rb->access_handler.flags);
	if (rb->access.unmark_in_use)
		rb->access.unmark_in_use(rb);

	return 0;
}

/**
 * iio_ring_rip_outer() - chrdev read for ring buffer access
 *
 * This function relies on all ring buffer implementations having an
 * iio_ring _bufer as their first element.
 **/
static ssize_t iio_ring_rip_outer(struct file *filp, char __user *buf,
				  size_t count, loff_t *f_ps)
{
	struct iio_ring_buffer *rb = filp->private_data;
	int ret, dead_offset, copied;
	u8 *data;
	/* rip lots must exist. */
	if (!rb->access.rip_lots)
		return -EINVAL;
	copied = rb->access.rip_lots(rb, count, &data, &dead_offset);

	if (copied < 0) {
		ret = copied;
		goto error_ret;
	}
	if (copy_to_user(buf, data + dead_offset, copied))  {
		ret =  -EFAULT;
		goto error_free_data_cpy;
	}
	/* In clever ring buffer designs this may not need to be freed.
	 * When such a design exists I'll add this to ring access funcs.
	 */
	kfree(data);

	return copied;

error_free_data_cpy:
	kfree(data);
error_ret:
	return ret;
}

static const struct file_operations iio_ring_fileops = {
	.read = iio_ring_rip_outer,
	.release = iio_ring_release,
	.open = iio_ring_open,
	.owner = THIS_MODULE,
};

/**
 * __iio_request_ring_buffer_event_chrdev() - allocate ring event chrdev
 * @buf:	ring buffer whose event chrdev we are allocating
 * @id:		id of this ring buffer (typically 0)
 * @owner:	the module who owns the ring buffer (for ref counting)
 * @dev:	device with which the chrdev is associated
 **/
static inline int
__iio_request_ring_buffer_event_chrdev(struct iio_ring_buffer *buf,
				       int id,
				       struct module *owner,
				       struct device *dev)
{
	int ret;

	snprintf(buf->ev_int._name, sizeof(buf->ev_int._name),
		 "%s:event%d",
		 dev_name(&buf->dev),
		 id);
	ret = iio_setup_ev_int(&(buf->ev_int),
			       buf->ev_int._name,
			       owner,
			       dev);
	if (ret)
		goto error_ret;
	return 0;

error_ret:
	return ret;
}

static inline void
__iio_free_ring_buffer_event_chrdev(struct iio_ring_buffer *buf)
{
	iio_free_ev_int(&(buf->ev_int));
}

static void iio_ring_access_release(struct device *dev)
{
	struct iio_ring_buffer *buf
		= access_dev_to_iio_ring_buffer(dev);
	cdev_del(&buf->access_handler.chrdev);
	iio_device_free_chrdev_minor(MINOR(dev->devt));
}

static struct device_type iio_ring_access_type = {
	.release = iio_ring_access_release,
};

static inline int
__iio_request_ring_buffer_access_chrdev(struct iio_ring_buffer *buf,
					int id,
					struct module *owner)
{
	int ret, minor;

	buf->access_handler.flags = 0;

	buf->access_dev.parent = &buf->dev;
	buf->access_dev.bus = &iio_bus_type;
	buf->access_dev.type = &iio_ring_access_type;
	device_initialize(&buf->access_dev);

	minor = iio_device_get_chrdev_minor();
	if (minor < 0) {
		ret = minor;
		goto error_device_put;
	}
	buf->access_dev.devt = MKDEV(MAJOR(iio_devt), minor);


	buf->access_id = id;

	dev_set_name(&buf->access_dev, "%s:access%d",
		     dev_name(&buf->dev),
		     buf->access_id);
	ret = device_add(&buf->access_dev);
	if (ret < 0) {
		printk(KERN_ERR "failed to add the ring access dev\n");
		goto error_device_put;
	}

	cdev_init(&buf->access_handler.chrdev, &iio_ring_fileops);
	buf->access_handler.chrdev.owner = owner;

	ret = cdev_add(&buf->access_handler.chrdev, buf->access_dev.devt, 1);
	if (ret) {
		printk(KERN_ERR "failed to allocate ring access chrdev\n");
		goto error_device_unregister;
	}
	return 0;

error_device_unregister:
	device_unregister(&buf->access_dev);
error_device_put:
	put_device(&buf->access_dev);

	return ret;
}

static void __iio_free_ring_buffer_access_chrdev(struct iio_ring_buffer *buf)
{
	device_unregister(&buf->access_dev);
}

void iio_ring_buffer_init(struct iio_ring_buffer *ring,
			  struct iio_dev *dev_info)
{
	if (ring->access.mark_param_change)
		ring->access.mark_param_change(ring);
	ring->indio_dev = dev_info;
	ring->ev_int.private = ring;
	ring->access_handler.private = ring;
	ring->shared_ev_pointer.ev_p = NULL;
	spin_lock_init(&ring->shared_ev_pointer.lock);
}
EXPORT_SYMBOL(iio_ring_buffer_init);

int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id)
{
	int ret;

	ring->id = id;

	dev_set_name(&ring->dev, "%s:buffer%d",
		     dev_name(ring->dev.parent),
		     ring->id);
	ret = device_add(&ring->dev);
	if (ret)
		goto error_ret;

	ret = __iio_request_ring_buffer_event_chrdev(ring,
						     0,
						     ring->owner,
						     &ring->dev);
	if (ret)
		goto error_remove_device;

	ret = __iio_request_ring_buffer_access_chrdev(ring,
						      0,
						      ring->owner);

	if (ret)
		goto error_free_ring_buffer_event_chrdev;

	if (ring->scan_el_attrs) {
		ret = sysfs_create_group(&ring->dev.kobj,
					 ring->scan_el_attrs);
		if (ret) {
			dev_err(&ring->dev,
				"Failed to add sysfs scan elements\n");
			goto error_free_ring_buffer_event_chrdev;
		}
	}

	return ret;
error_free_ring_buffer_event_chrdev:
	__iio_free_ring_buffer_event_chrdev(ring);
error_remove_device:
	device_del(&ring->dev);
error_ret:
	return ret;
}
EXPORT_SYMBOL(iio_ring_buffer_register);

void iio_ring_buffer_unregister(struct iio_ring_buffer *ring)
{
	if (ring->scan_el_attrs)
		sysfs_remove_group(&ring->dev.kobj,
				   ring->scan_el_attrs);

	__iio_free_ring_buffer_access_chrdev(ring);
	__iio_free_ring_buffer_event_chrdev(ring);
	device_del(&ring->dev);
}
EXPORT_SYMBOL(iio_ring_buffer_unregister);

ssize_t iio_read_ring_length(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
	int len = 0;
	struct iio_ring_buffer *ring = dev_get_drvdata(dev);

	if (ring->access.get_length)
		len = sprintf(buf, "%d\n",
			      ring->access.get_length(ring));

	return len;
}
EXPORT_SYMBOL(iio_read_ring_length);

 ssize_t iio_write_ring_length(struct device *dev,
			       struct device_attribute *attr,
			       const char *buf,
			       size_t len)
{
	int ret;
	ulong val;
	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	ret = strict_strtoul(buf, 10, &val);
	if (ret)
		return ret;

	if (ring->access.get_length)
		if (val == ring->access.get_length(ring))
			return len;

	if (ring->access.set_length) {
		ring->access.set_length(ring, val);
		if (ring->access.mark_param_change)
			ring->access.mark_param_change(ring);
	}

	return len;
}
EXPORT_SYMBOL(iio_write_ring_length);

ssize_t iio_read_ring_bytes_per_datum(struct device *dev,
			  struct device_attribute *attr,
			  char *buf)
{
	int len = 0;
	struct iio_ring_buffer *ring = dev_get_drvdata(dev);

	if (ring->access.get_bytes_per_datum)
		len = sprintf(buf, "%d\n",
			      ring->access.get_bytes_per_datum(ring));

	return len;
}
EXPORT_SYMBOL(iio_read_ring_bytes_per_datum);

ssize_t iio_store_ring_enable(struct device *dev,
			      struct device_attribute *attr,
			      const char *buf,
			      size_t len)
{
	int ret;
	bool requested_state, current_state;
	int previous_mode;
	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	struct iio_dev *dev_info = ring->indio_dev;

	mutex_lock(&dev_info->mlock);
	previous_mode = dev_info->currentmode;
	requested_state = !(buf[0] == '0');
	current_state = !!(previous_mode & INDIO_ALL_RING_MODES);
	if (current_state == requested_state) {
		printk(KERN_INFO "iio-ring, current state requested again\n");
		goto done;
	}
	if (requested_state) {
		if (ring->preenable) {
			ret = ring->preenable(dev_info);
			if (ret) {
				printk(KERN_ERR
				       "Buffer not started:"
				       "ring preenable failed\n");
				goto error_ret;
			}
		}
		if (ring->access.request_update) {
			ret = ring->access.request_update(ring);
			if (ret) {
				printk(KERN_INFO
				       "Buffer not started:"
				       "ring parameter update failed\n");
				goto error_ret;
			}
		}
		if (ring->access.mark_in_use)
			ring->access.mark_in_use(ring);
		/* Definitely possible for devices to support both of these.*/
		if (dev_info->modes & INDIO_RING_TRIGGERED) {
			if (!dev_info->trig) {
				printk(KERN_INFO
				       "Buffer not started: no trigger\n");
				ret = -EINVAL;
				if (ring->access.unmark_in_use)
					ring->access.unmark_in_use(ring);
				goto error_ret;
			}
			dev_info->currentmode = INDIO_RING_TRIGGERED;
		} else if (dev_info->modes & INDIO_RING_HARDWARE_BUFFER)
			dev_info->currentmode = INDIO_RING_HARDWARE_BUFFER;
		else { /* should never be reached */
			ret = -EINVAL;
			goto error_ret;
		}

		if (ring->postenable) {

			ret = ring->postenable(dev_info);
			if (ret) {
				printk(KERN_INFO
				       "Buffer not started:"
				       "postenable failed\n");
				if (ring->access.unmark_in_use)
					ring->access.unmark_in_use(ring);
				dev_info->currentmode = previous_mode;
				if (ring->postdisable)
					ring->postdisable(dev_info);
				goto error_ret;
			}
		}
	} else {
		if (ring->predisable) {
			ret = ring->predisable(dev_info);
			if (ret)
				goto error_ret;
		}
		if (ring->access.unmark_in_use)
			ring->access.unmark_in_use(ring);
		dev_info->currentmode = INDIO_DIRECT_MODE;
		if (ring->postdisable) {
			ret = ring->postdisable(dev_info);
			if (ret)
				goto error_ret;
		}
	}
done:
	mutex_unlock(&dev_info->mlock);
	return len;

error_ret:
	mutex_unlock(&dev_info->mlock);
	return ret;
}
EXPORT_SYMBOL(iio_store_ring_enable);
ssize_t iio_show_ring_enable(struct device *dev,
				    struct device_attribute *attr,
				    char *buf)
{
	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	return sprintf(buf, "%d\n", !!(ring->indio_dev->currentmode
				       & INDIO_ALL_RING_MODES));
}
EXPORT_SYMBOL(iio_show_ring_enable);

ssize_t iio_scan_el_show(struct device *dev,
			 struct device_attribute *attr,
			 char *buf)
{
	int ret;
	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	struct iio_scan_el *this_el = to_iio_scan_el(attr);

	ret = iio_scan_mask_query(ring, this_el->number);
	if (ret < 0)
		return ret;
	return sprintf(buf, "%d\n", ret);
}
EXPORT_SYMBOL(iio_scan_el_show);

ssize_t iio_scan_el_store(struct device *dev,
			  struct device_attribute *attr,
			  const char *buf,
			  size_t len)
{
	int ret = 0;
	bool state;
	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	struct iio_dev *indio_dev = ring->indio_dev;
	struct iio_scan_el *this_el = to_iio_scan_el(attr);

	state = !(buf[0] == '0');
	mutex_lock(&indio_dev->mlock);
	if (indio_dev->currentmode == INDIO_RING_TRIGGERED) {
		ret = -EBUSY;
		goto error_ret;
	}
	ret = iio_scan_mask_query(ring, this_el->number);
	if (ret < 0)
		goto error_ret;
	if (!state && ret) {
		ret = iio_scan_mask_clear(ring, this_el->number);
		if (ret)
			goto error_ret;
	} else if (state && !ret) {
		ret = iio_scan_mask_set(ring, this_el->number);
		if (ret)
			goto error_ret;
	}
	if (this_el->set_state)
		ret = this_el->set_state(this_el, indio_dev, state);
error_ret:
	mutex_unlock(&indio_dev->mlock);

	return ret ? ret : len;

}
EXPORT_SYMBOL(iio_scan_el_store);

ssize_t iio_scan_el_ts_show(struct device *dev,
			    struct device_attribute *attr,
			    char *buf)
{
	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	return sprintf(buf, "%d\n", ring->scan_timestamp);
}
EXPORT_SYMBOL(iio_scan_el_ts_show);

ssize_t iio_scan_el_ts_store(struct device *dev,
			     struct device_attribute *attr,
			     const char *buf,
			     size_t len)
{
	int ret = 0;
	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	struct iio_dev *indio_dev = ring->indio_dev;
	bool state;
	state = !(buf[0] == '0');
	mutex_lock(&indio_dev->mlock);
	if (indio_dev->currentmode == INDIO_RING_TRIGGERED) {
		ret = -EBUSY;
		goto error_ret;
	}
	ring->scan_timestamp = state;
error_ret:
	mutex_unlock(&indio_dev->mlock);

	return ret ? ret : len;
}
EXPORT_SYMBOL(iio_scan_el_ts_store);
Commit	Line	Data
7026ea4b JC	1	/* The industrial I/O core
	2	*
	3	* Copyright (c) 2008 Jonathan Cameron
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License version 2 as published by
	7	* the Free Software Foundation.
	8	*
	9	* Handling of ring allocation / resizing.
	10	*
	11	*
	12	* Things to look at here.
	13	* - Better memory allocation techniques?
	14	* - Alternative access techniques?
	15	*/
	16	#include <linux/kernel.h>
	17	#include <linux/device.h>
7026ea4b JC	18	#include <linux/fs.h>
7026ea4b JC	19	#include <linux/poll.h>
7026ea4b	20	#include <linux/cdev.h>
5a0e3ad6	21	#include <linux/slab.h>
7026ea4b JC	22
	23	#include "iio.h"
	24	#include "ring_generic.h"
	25
7026ea4b JC	26	int iio_push_ring_event(struct iio_ring_buffer *ring_buf,
	27	int event_code,
	28	s64 timestamp)
	29	{
	30	return __iio_push_event(&ring_buf->ev_int,
	31	event_code,
	32	timestamp,
	33	&ring_buf->shared_ev_pointer);
	34	}
	35	EXPORT_SYMBOL(iio_push_ring_event);
	36
	37	int iio_push_or_escallate_ring_event(struct iio_ring_buffer *ring_buf,
	38	int event_code,
	39	s64 timestamp)
	40	{
	41	if (ring_buf->shared_ev_pointer.ev_p)
	42	__iio_change_event(ring_buf->shared_ev_pointer.ev_p,
	43	event_code,
	44	timestamp);
	45	else
	46	return iio_push_ring_event(ring_buf,
	47	event_code,
	48	timestamp);
	49	return 0;
	50	}
	51	EXPORT_SYMBOL(iio_push_or_escallate_ring_event);
	52
	53	/**
c3e5d410	54	* iio_ring_open() - chrdev file open for ring buffer access
7026ea4b JC	55	*
	56	* This function relies on all ring buffer implementations having an
	57	* iio_ring_buffer as their first element.
	58	**/
0deebb4f	59	static int iio_ring_open(struct inode inode, struct file filp)
7026ea4b JC	60	{
	61	struct iio_handler *hand
	62	= container_of(inode->i_cdev, struct iio_handler, chrdev);
	63	struct iio_ring_buffer *rb = hand->private;
	64
	65	filp->private_data = hand->private;
	66	if (rb->access.mark_in_use)
	67	rb->access.mark_in_use(rb);
	68
	69	return 0;
	70	}
	71
	72	/**
c3e5d410	73	* iio_ring_release() - chrdev file close ring buffer access
7026ea4b JC	74	*
	75	* This function relies on all ring buffer implementations having an
	76	* iio_ring_buffer as their first element.
	77	**/
0deebb4f	78	static int iio_ring_release(struct inode inode, struct file filp)
7026ea4b JC	79	{
	80	struct cdev *cd = inode->i_cdev;
	81	struct iio_handler *hand = iio_cdev_to_handler(cd);
	82	struct iio_ring_buffer *rb = hand->private;
	83
	84	clear_bit(IIO_BUSY_BIT_POS, &rb->access_handler.flags);
	85	if (rb->access.unmark_in_use)
	86	rb->access.unmark_in_use(rb);
	87
	88	return 0;
	89	}
	90
	91	/**
c3e5d410	92	* iio_ring_rip_outer() - chrdev read for ring buffer access
7026ea4b JC	93	*
	94	* This function relies on all ring buffer implementations having an
	95	* iio_ring _bufer as their first element.
	96	**/
0deebb4f GKH	97	static ssize_t iio_ring_rip_outer(struct file filp, char __user buf,
0deebb4f GKH	98	size_t count, loff_t *f_ps)
7026ea4b JC	99	{
	100	struct iio_ring_buffer *rb = filp->private_data;
	101	int ret, dead_offset, copied;
	102	u8 *data;
	103	/* rip lots must exist. */
	104	if (!rb->access.rip_lots)
	105	return -EINVAL;
	106	copied = rb->access.rip_lots(rb, count, &data, &dead_offset);
	107
	108	if (copied < 0) {
	109	ret = copied;
	110	goto error_ret;
	111	}
	112	if (copy_to_user(buf, data + dead_offset, copied)) {
	113	ret = -EFAULT;
	114	goto error_free_data_cpy;
	115	}
	116	/* In clever ring buffer designs this may not need to be freed.
	117	* When such a design exists I'll add this to ring access funcs.
	118	*/
	119	kfree(data);
	120
	121	return copied;
	122
	123	error_free_data_cpy:
	124	kfree(data);
	125	error_ret:
	126	return ret;
	127	}
	128
	129	static const struct file_operations iio_ring_fileops = {
	130	.read = iio_ring_rip_outer,
	131	.release = iio_ring_release,
	132	.open = iio_ring_open,
	133	.owner = THIS_MODULE,
	134	};
	135
	136	/**
c3e5d410	137	* __iio_request_ring_buffer_event_chrdev() - allocate ring event chrdev
7026ea4b	138	* @buf: ring buffer whose event chrdev we are allocating
c3e5d410	139	* @id: id of this ring buffer (typically 0)
7026ea4b JC	140	* @owner: the module who owns the ring buffer (for ref counting)
	141	* @dev: device with which the chrdev is associated
	142	**/
	143	static inline int
	144	__iio_request_ring_buffer_event_chrdev(struct iio_ring_buffer *buf,
	145	int id,
	146	struct module *owner,
	147	struct device *dev)
	148	{
	149	int ret;
758d988c	150
ba5c6fba JC	151	snprintf(buf->ev_int._name, sizeof(buf->ev_int._name),
	152	"%s:event%d",
	153	dev_name(&buf->dev),
3d550fba	154	id);
7026ea4b JC	155	ret = iio_setup_ev_int(&(buf->ev_int),
	156	buf->ev_int._name,
	157	owner,
	158	dev);
	159	if (ret)
758d988c	160	goto error_ret;
7026ea4b JC	161	return 0;
7026ea4b JC	162
7026ea4b JC	163	error_ret:
	164	return ret;
	165	}
	166
	167	static inline void
	168	__iio_free_ring_buffer_event_chrdev(struct iio_ring_buffer *buf)
	169	{
	170	iio_free_ev_int(&(buf->ev_int));
7026ea4b JC	171	}
	172
	173	static void iio_ring_access_release(struct device *dev)
	174	{
	175	struct iio_ring_buffer *buf
	176	= access_dev_to_iio_ring_buffer(dev);
	177	cdev_del(&buf->access_handler.chrdev);
	178	iio_device_free_chrdev_minor(MINOR(dev->devt));
	179	}
	180
	181	static struct device_type iio_ring_access_type = {
	182	.release = iio_ring_access_release,
	183	};
	184
	185	static inline int
	186	__iio_request_ring_buffer_access_chrdev(struct iio_ring_buffer *buf,
	187	int id,
	188	struct module *owner)
	189	{
	190	int ret, minor;
	191
	192	buf->access_handler.flags = 0;
	193
	194	buf->access_dev.parent = &buf->dev;
5aaaeba8	195	buf->access_dev.bus = &iio_bus_type;
7026ea4b JC	196	buf->access_dev.type = &iio_ring_access_type;
	197	device_initialize(&buf->access_dev);
	198
	199	minor = iio_device_get_chrdev_minor();
	200	if (minor < 0) {
	201	ret = minor;
	202	goto error_device_put;
	203	}
	204	buf->access_dev.devt = MKDEV(MAJOR(iio_devt), minor);
	205
758d988c JC	206
	207	buf->access_id = id;
	208
ba5c6fba JC	209	dev_set_name(&buf->access_dev, "%s:access%d",
	210	dev_name(&buf->dev),
	211	buf->access_id);
7026ea4b JC	212	ret = device_add(&buf->access_dev);
	213	if (ret < 0) {
	214	printk(KERN_ERR "failed to add the ring access dev\n");
758d988c	215	goto error_device_put;
7026ea4b JC	216	}
	217
	218	cdev_init(&buf->access_handler.chrdev, &iio_ring_fileops);
	219	buf->access_handler.chrdev.owner = owner;
	220
	221	ret = cdev_add(&buf->access_handler.chrdev, buf->access_dev.devt, 1);
	222	if (ret) {
	223	printk(KERN_ERR "failed to allocate ring access chrdev\n");
	224	goto error_device_unregister;
	225	}
	226	return 0;
758d988c	227
7026ea4b JC	228	error_device_unregister:
7026ea4b JC	229	device_unregister(&buf->access_dev);
7026ea4b JC	230	error_device_put:
	231	put_device(&buf->access_dev);
	232
	233	return ret;
	234	}
	235
	236	static void __iio_free_ring_buffer_access_chrdev(struct iio_ring_buffer *buf)
	237	{
7026ea4b JC	238	device_unregister(&buf->access_dev);
	239	}
	240
	241	void iio_ring_buffer_init(struct iio_ring_buffer *ring,
	242	struct iio_dev *dev_info)
	243	{
	244	if (ring->access.mark_param_change)
	245	ring->access.mark_param_change(ring);
	246	ring->indio_dev = dev_info;
	247	ring->ev_int.private = ring;
	248	ring->access_handler.private = ring;
0deebb4f	249	ring->shared_ev_pointer.ev_p = NULL;
6f2dfb31	250	spin_lock_init(&ring->shared_ev_pointer.lock);
7026ea4b JC	251	}
	252	EXPORT_SYMBOL(iio_ring_buffer_init);
	253
758d988c	254	int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id)
7026ea4b JC	255	{
7026ea4b JC	256	int ret;
758d988c JC	257
758d988c JC	258	ring->id = id;
7026ea4b	259
ba5c6fba JC	260	dev_set_name(&ring->dev, "%s:buffer%d",
	261	dev_name(ring->dev.parent),
	262	ring->id);
7026ea4b JC	263	ret = device_add(&ring->dev);
7026ea4b JC	264	if (ret)
758d988c	265	goto error_ret;
7026ea4b JC	266
	267	ret = __iio_request_ring_buffer_event_chrdev(ring,
	268	0,
	269	ring->owner,
	270	&ring->dev);
	271	if (ret)
	272	goto error_remove_device;
	273
	274	ret = __iio_request_ring_buffer_access_chrdev(ring,
	275	0,
	276	ring->owner);
	277
	278	if (ret)
	279	goto error_free_ring_buffer_event_chrdev;
	280
bf32963c MS	281	if (ring->scan_el_attrs) {
	282	ret = sysfs_create_group(&ring->dev.kobj,
	283	ring->scan_el_attrs);
	284	if (ret) {
	285	dev_err(&ring->dev,
	286	"Failed to add sysfs scan elements\n");
	287	goto error_free_ring_buffer_event_chrdev;
	288	}
	289	}
	290
7026ea4b JC	291	return ret;
	292	error_free_ring_buffer_event_chrdev:
	293	__iio_free_ring_buffer_event_chrdev(ring);
	294	error_remove_device:
	295	device_del(&ring->dev);
7026ea4b JC	296	error_ret:
	297	return ret;
	298	}
	299	EXPORT_SYMBOL(iio_ring_buffer_register);
	300
	301	void iio_ring_buffer_unregister(struct iio_ring_buffer *ring)
	302	{
bf32963c MS	303	if (ring->scan_el_attrs)
	304	sysfs_remove_group(&ring->dev.kobj,
	305	ring->scan_el_attrs);
	306
7026ea4b JC	307	__iio_free_ring_buffer_access_chrdev(ring);
	308	__iio_free_ring_buffer_event_chrdev(ring);
	309	device_del(&ring->dev);
7026ea4b JC	310	}
	311	EXPORT_SYMBOL(iio_ring_buffer_unregister);
	312
	313	ssize_t iio_read_ring_length(struct device *dev,
	314	struct device_attribute *attr,
	315	char *buf)
	316	{
	317	int len = 0;
	318	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	319
	320	if (ring->access.get_length)
	321	len = sprintf(buf, "%d\n",
	322	ring->access.get_length(ring));
	323
	324	return len;
	325	}
	326	EXPORT_SYMBOL(iio_read_ring_length);
	327
	328	ssize_t iio_write_ring_length(struct device *dev,
	329	struct device_attribute *attr,
	330	const char *buf,
	331	size_t len)
	332	{
	333	int ret;
	334	ulong val;
	335	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	336	ret = strict_strtoul(buf, 10, &val);
	337	if (ret)
	338	return ret;
	339
	340	if (ring->access.get_length)
	341	if (val == ring->access.get_length(ring))
	342	return len;
	343
	344	if (ring->access.set_length) {
	345	ring->access.set_length(ring, val);
	346	if (ring->access.mark_param_change)
	347	ring->access.mark_param_change(ring);
	348	}
	349
	350	return len;
	351	}
	352	EXPORT_SYMBOL(iio_write_ring_length);
	353
ffcab07a	354	ssize_t iio_read_ring_bytes_per_datum(struct device *dev,
7026ea4b JC	355	struct device_attribute *attr,
	356	char *buf)
	357	{
	358	int len = 0;
	359	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	360
ffcab07a	361	if (ring->access.get_bytes_per_datum)
7026ea4b	362	len = sprintf(buf, "%d\n",
ffcab07a	363	ring->access.get_bytes_per_datum(ring));
7026ea4b JC	364
	365	return len;
	366	}
ffcab07a	367	EXPORT_SYMBOL(iio_read_ring_bytes_per_datum);
7026ea4b JC	368
	369	ssize_t iio_store_ring_enable(struct device *dev,
	370	struct device_attribute *attr,
	371	const char *buf,
	372	size_t len)
	373	{
	374	int ret;
	375	bool requested_state, current_state;
	376	int previous_mode;
	377	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	378	struct iio_dev *dev_info = ring->indio_dev;
	379
	380	mutex_lock(&dev_info->mlock);
	381	previous_mode = dev_info->currentmode;
	382	requested_state = !(buf[0] == '0');
	383	current_state = !!(previous_mode & INDIO_ALL_RING_MODES);
	384	if (current_state == requested_state) {
	385	printk(KERN_INFO "iio-ring, current state requested again\n");
	386	goto done;
	387	}
	388	if (requested_state) {
	389	if (ring->preenable) {
	390	ret = ring->preenable(dev_info);
	391	if (ret) {
	392	printk(KERN_ERR
	393	"Buffer not started:"
	394	"ring preenable failed\n");
	395	goto error_ret;
	396	}
	397	}
	398	if (ring->access.request_update) {
	399	ret = ring->access.request_update(ring);
	400	if (ret) {
	401	printk(KERN_INFO
	402	"Buffer not started:"
	403	"ring parameter update failed\n");
	404	goto error_ret;
	405	}
	406	}
	407	if (ring->access.mark_in_use)
	408	ring->access.mark_in_use(ring);
	409	/* Definitely possible for devices to support both of these.*/
	410	if (dev_info->modes & INDIO_RING_TRIGGERED) {
	411	if (!dev_info->trig) {
	412	printk(KERN_INFO
	413	"Buffer not started: no trigger\n");
	414	ret = -EINVAL;
	415	if (ring->access.unmark_in_use)
	416	ring->access.unmark_in_use(ring);
	417	goto error_ret;
	418	}
	419	dev_info->currentmode = INDIO_RING_TRIGGERED;
	420	} else if (dev_info->modes & INDIO_RING_HARDWARE_BUFFER)
	421	dev_info->currentmode = INDIO_RING_HARDWARE_BUFFER;
	422	else { /* should never be reached */
	423	ret = -EINVAL;
	424	goto error_ret;
	425	}
	426
	427	if (ring->postenable) {
	428
	429	ret = ring->postenable(dev_info);
	430	if (ret) {
	431	printk(KERN_INFO
432	"Buffer not started:"
433	"postenable failed\n");
434	if (ring->access.unmark_in_use)
435	ring->access.unmark_in_use(ring);
436	dev_info->currentmode = previous_mode;
437	if (ring->postdisable)
438	ring->postdisable(dev_info);
439	goto error_ret;
440	}
441	}
442	} else {
443	if (ring->predisable) {
444	ret = ring->predisable(dev_info);
445	if (ret)
446	goto error_ret;
447	}
448	if (ring->access.unmark_in_use)
449	ring->access.unmark_in_use(ring);
450	dev_info->currentmode = INDIO_DIRECT_MODE;
451	if (ring->postdisable) {
452	ret = ring->postdisable(dev_info);
453	if (ret)
454	goto error_ret;
455	}
456	}
457	done:
458	mutex_unlock(&dev_info->mlock);
459	return len;
460
461	error_ret:
462	mutex_unlock(&dev_info->mlock);
463	return ret;
464	}
465	EXPORT_SYMBOL(iio_store_ring_enable);
466	ssize_t iio_show_ring_enable(struct device *dev,
467	struct device_attribute *attr,
468	char *buf)
469	{
470	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
471	return sprintf(buf, "%d\n", !!(ring->indio_dev->currentmode
472	& INDIO_ALL_RING_MODES));
473	}
474	EXPORT_SYMBOL(iio_show_ring_enable);
475
476	ssize_t iio_scan_el_show(struct device *dev,
477	struct device_attribute *attr,
478	char *buf)
479	{
480	int ret;
bf32963c	481	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
7026ea4b JC	482	struct iio_scan_el *this_el = to_iio_scan_el(attr);
7026ea4b JC	483
bf32963c	484	ret = iio_scan_mask_query(ring, this_el->number);
7026ea4b JC	485	if (ret < 0)
	486	return ret;
	487	return sprintf(buf, "%d\n", ret);
	488	}
	489	EXPORT_SYMBOL(iio_scan_el_show);
	490
	491	ssize_t iio_scan_el_store(struct device *dev,
	492	struct device_attribute *attr,
	493	const char *buf,
	494	size_t len)
	495	{
	496	int ret = 0;
	497	bool state;
bf32963c MS	498	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
bf32963c MS	499	struct iio_dev *indio_dev = ring->indio_dev;
7026ea4b JC	500	struct iio_scan_el *this_el = to_iio_scan_el(attr);
	501
	502	state = !(buf[0] == '0');
	503	mutex_lock(&indio_dev->mlock);
	504	if (indio_dev->currentmode == INDIO_RING_TRIGGERED) {
	505	ret = -EBUSY;
	506	goto error_ret;
	507	}
bf32963c	508	ret = iio_scan_mask_query(ring, this_el->number);
7026ea4b JC	509	if (ret < 0)
	510	goto error_ret;
	511	if (!state && ret) {
bf32963c	512	ret = iio_scan_mask_clear(ring, this_el->number);
7026ea4b JC	513	if (ret)
7026ea4b JC	514	goto error_ret;
7026ea4b	515	} else if (state && !ret) {
bf32963c	516	ret = iio_scan_mask_set(ring, this_el->number);
7026ea4b JC	517	if (ret)
7026ea4b JC	518	goto error_ret;
7026ea4b JC	519	}
	520	if (this_el->set_state)
	521	ret = this_el->set_state(this_el, indio_dev, state);
	522	error_ret:
	523	mutex_unlock(&indio_dev->mlock);
	524
	525	return ret ? ret : len;
	526
	527	}
	528	EXPORT_SYMBOL(iio_scan_el_store);
	529
	530	ssize_t iio_scan_el_ts_show(struct device *dev,
	531	struct device_attribute *attr,
	532	char *buf)
	533	{
bf32963c MS	534	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
bf32963c MS	535	return sprintf(buf, "%d\n", ring->scan_timestamp);
7026ea4b JC	536	}
	537	EXPORT_SYMBOL(iio_scan_el_ts_show);
	538
	539	ssize_t iio_scan_el_ts_store(struct device *dev,
	540	struct device_attribute *attr,
	541	const char *buf,
	542	size_t len)
	543	{
	544	int ret = 0;
bf32963c MS	545	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
bf32963c MS	546	struct iio_dev *indio_dev = ring->indio_dev;
7026ea4b JC	547	bool state;
	548	state = !(buf[0] == '0');
	549	mutex_lock(&indio_dev->mlock);
	550	if (indio_dev->currentmode == INDIO_RING_TRIGGERED) {
	551	ret = -EBUSY;
	552	goto error_ret;
	553	}
bf32963c	554	ring->scan_timestamp = state;
7026ea4b JC	555	error_ret:
	556	mutex_unlock(&indio_dev->mlock);
	557
	558	return ret ? ret : len;
	559	}
	560	EXPORT_SYMBOL(iio_scan_el_ts_store);
	561