[deliverable/linux.git] / drivers / staging / iio / accel / sca3000_ring.c

/*
 * sca3000_ring.c -- support VTI sca3000 series accelerometers via SPI
 *
 * 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.
 *
 * Copyright (c) 2009 Jonathan Cameron <jic23@cam.ac.uk>
 *
 */

#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/sysfs.h>

#include "../iio.h"
#include "../sysfs.h"
#include "../ring_generic.h"
#include "../ring_hw.h"
#include "accel.h"
#include "sca3000.h"

/* RFC / future work
 *
 * The internal ring buffer doesn't actually change what it holds depending
 * on which signals are enabled etc, merely whether you can read them.
 * As such the scan mode selection is somewhat different than for a software
 * ring buffer and changing it actually covers any data already in the buffer.
 * Currently scan elements aren't configured so it doesn't matter.
 */

/**
 * sca3000_rip_hw_rb() - main ring access function, pulls data from ring
 * @r:			the ring
 * @count:		number of samples to try and pull
 * @data:		output the actual samples pulled from the hw ring
 * @dead_offset:	cheating a bit here: Set to 1 so as to allow for the
 *			leading byte used in bus comms.
 *
 * Currently does not provide timestamps.  As the hardware doesn't add them they
 * can only be inferred aproximately from ring buffer events such as 50% full
 * and knowledge of when buffer was last emptied.  This is left to userspace.
 **/
static int sca3000_rip_hw_rb(struct iio_ring_buffer *r,
			     size_t count, u8 **data, int *dead_offset)
{
	struct iio_hw_ring_buffer *hw_ring = iio_to_hw_ring_buf(r);
	struct iio_dev *indio_dev = hw_ring->private;
	struct sca3000_state *st = indio_dev->dev_data;
	u8 *rx;
	int ret, num_available, num_read = 0;
	int bytes_per_sample = 1;

	if (st->bpse == 11)
		bytes_per_sample = 2;

	mutex_lock(&st->lock);
	/* Check how much data is available:
	 * RFC: Implement an ioctl to not bother checking whether there
	 * is enough data in the ring?  Afterall, if we are responding
	 * to an interrupt we have a minimum content guaranteed so it
	 * seems slight silly to waste time checking it is there.
	 */
	ret = sca3000_read_data(st,
				SCA3000_REG_ADDR_BUF_COUNT,
				&rx, 1);
	if (ret)
		goto error_ret;
	else
		num_available = rx[1];
	/* num_available is the total number of samples available
	 * i.e. number of time points * number of channels.
	 */
	kfree(rx);
	if (count > num_available * bytes_per_sample)
		num_read = num_available*bytes_per_sample;
	else
		num_read = count - (count % (bytes_per_sample));

	/* Avoid the read request byte */
	*dead_offset = 1;
	ret = sca3000_read_data(st,
				SCA3000_REG_ADDR_RING_OUT,
				data, num_read);
error_ret:
	mutex_unlock(&st->lock);

	return ret ? ret : num_read;
}

/* This is only valid with all 3 elements enabled */
static int sca3000_ring_get_length(struct iio_ring_buffer *r)
{
	return 64;
}

/* only valid if resolution is kept at 11bits */
static int sca3000_ring_get_bytes_per_datum(struct iio_ring_buffer *r)
{
	return 6;
}
static void sca3000_ring_release(struct device *dev)
{
	struct iio_ring_buffer *r = to_iio_ring_buffer(dev);
	kfree(iio_to_hw_ring_buf(r));
}

static IIO_RING_ENABLE_ATTR;
static IIO_RING_BYTES_PER_DATUM_ATTR;
static IIO_RING_LENGTH_ATTR;

/**
 * sca3000_show_ring_bpse() -sysfs function to query bits per sample from ring
 * @dev: ring buffer device
 * @attr: this device attribute
 * @buf: buffer to write to
 **/
static ssize_t sca3000_show_ring_bpse(struct device *dev,
				      struct device_attribute *attr,
				      char *buf)
{
	int len = 0, ret;
	u8 *rx;
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct sca3000_state *st = indio_dev->dev_data;

	mutex_lock(&st->lock);
	ret = sca3000_read_data(st, SCA3000_REG_ADDR_MODE, &rx, 1);
	if (ret)
		goto error_ret;
	len = sprintf(buf, "%d\n", (rx[1] & SCA3000_RING_BUF_8BIT) ? 8 : 11);
	kfree(rx);
error_ret:
	mutex_unlock(&st->lock);

	return ret ? ret : len;
}

/**
 * sca3000_store_ring_bpse() - bits per scan element
 * @dev: ring buffer device
 * @attr: attribute called from
 * @buf: input from userspace
 * @len: length of input
 **/
static ssize_t sca3000_store_ring_bpse(struct device *dev,
				      struct device_attribute *attr,
				      const char *buf,
				      size_t len)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct sca3000_state *st = indio_dev->dev_data;
	int ret;
	u8 *rx;
	long val;
	ret = strict_strtol(buf, 10, &val);
	if (ret)
		return ret;

	mutex_lock(&st->lock);

	ret = sca3000_read_data(st, SCA3000_REG_ADDR_MODE, &rx, 1);
	if (!ret)
		switch (val) {
		case 8:
			ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
						rx[1] | SCA3000_RING_BUF_8BIT);
			st->bpse = 8;
			break;
		case 11:
			ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
						rx[1] & ~SCA3000_RING_BUF_8BIT);
			st->bpse = 11;
			break;
		default:
			ret = -EINVAL;
			break;
		}
	mutex_unlock(&st->lock);

	return ret ? ret : len;
}

static IIO_SCAN_EL_C(accel_x, 0, 0, 0, NULL);
static IIO_SCAN_EL_C(accel_y, 1, 0, 0, NULL);
static IIO_SCAN_EL_C(accel_z, 2, 0, 0, NULL);
static IIO_CONST_ATTR(accel_precision_available, "8 11");
static IIO_DEVICE_ATTR(accel_precision,
		       S_IRUGO | S_IWUSR,
		       sca3000_show_ring_bpse,
		       sca3000_store_ring_bpse,
		       0);

static struct attribute *sca3000_scan_el_attrs[] = {
	&iio_scan_el_accel_x.dev_attr.attr,
	&iio_scan_el_accel_y.dev_attr.attr,
	&iio_scan_el_accel_z.dev_attr.attr,
	&iio_const_attr_accel_precision_available.dev_attr.attr,
	&iio_dev_attr_accel_precision.dev_attr.attr,
	NULL
};

static struct attribute_group sca3000_scan_el_group = {
	.attrs = sca3000_scan_el_attrs,
	.name = "scan_elements",
};

/*
 * Ring buffer attributes
 * This device is a bit unusual in that the sampling frequency and bpse
 * only apply to the ring buffer.  At all times full rate and accuracy
 * is available via direct reading from registers.
 */
static struct attribute *sca3000_ring_attributes[] = {
	&dev_attr_length.attr,
	&dev_attr_bytes_per_datum.attr,
	&dev_attr_enable.attr,
	NULL,
};

static struct attribute_group sca3000_ring_attr = {
	.attrs = sca3000_ring_attributes,
};

static const struct attribute_group *sca3000_ring_attr_groups[] = {
	&sca3000_ring_attr,
	NULL
};

static struct device_type sca3000_ring_type = {
	.release = sca3000_ring_release,
	.groups = sca3000_ring_attr_groups,
};

static struct iio_ring_buffer *sca3000_rb_allocate(struct iio_dev *indio_dev)
{
	struct iio_ring_buffer *buf;
	struct iio_hw_ring_buffer *ring;

	ring = kzalloc(sizeof *ring, GFP_KERNEL);
	if (!ring)
		return NULL;
	ring->private = indio_dev;
	buf = &ring->buf;
	iio_ring_buffer_init(buf, indio_dev);
	buf->dev.type = &sca3000_ring_type;
	device_initialize(&buf->dev);
	buf->dev.parent = &indio_dev->dev;
	dev_set_drvdata(&buf->dev, (void *)buf);

	return buf;
}

static inline void sca3000_rb_free(struct iio_ring_buffer *r)
{
	if (r)
		iio_put_ring_buffer(r);
}

int sca3000_configure_ring(struct iio_dev *indio_dev)
{
	indio_dev->ring = sca3000_rb_allocate(indio_dev);
	if (indio_dev->ring == NULL)
		return -ENOMEM;
	indio_dev->modes |= INDIO_RING_HARDWARE_BUFFER;

	indio_dev->ring->scan_el_attrs = &sca3000_scan_el_group;
	indio_dev->ring->access.rip_lots = &sca3000_rip_hw_rb;
	indio_dev->ring->access.get_length = &sca3000_ring_get_length;
	indio_dev->ring->access.get_bytes_per_datum = &sca3000_ring_get_bytes_per_datum;

	return 0;
}

void sca3000_unconfigure_ring(struct iio_dev *indio_dev)
{
	sca3000_rb_free(indio_dev->ring);
}

static inline
int __sca3000_hw_ring_state_set(struct iio_dev *indio_dev, bool state)
{
	struct sca3000_state *st = indio_dev->dev_data;
	int ret;
	u8 *rx;

	mutex_lock(&st->lock);
	ret = sca3000_read_data(st, SCA3000_REG_ADDR_MODE, &rx, 1);
	if (ret)
		goto error_ret;
	if (state) {
		printk(KERN_INFO "supposedly enabling ring buffer\n");
		ret = sca3000_write_reg(st,
					SCA3000_REG_ADDR_MODE,
					(rx[1] | SCA3000_RING_BUF_ENABLE));
	} else
		ret = sca3000_write_reg(st,
					SCA3000_REG_ADDR_MODE,
					(rx[1] & ~SCA3000_RING_BUF_ENABLE));
	kfree(rx);
error_ret:
	mutex_unlock(&st->lock);

	return ret;
}
/**
 * sca3000_hw_ring_preenable() hw ring buffer preenable function
 *
 * Very simple enable function as the chip will allows normal reads
 * during ring buffer operation so as long as it is indeed running
 * before we notify the core, the precise ordering does not matter.
 **/
static int sca3000_hw_ring_preenable(struct iio_dev *indio_dev)
{
	return __sca3000_hw_ring_state_set(indio_dev, 1);
}

static int sca3000_hw_ring_postdisable(struct iio_dev *indio_dev)
{
	return __sca3000_hw_ring_state_set(indio_dev, 0);
}

void sca3000_register_ring_funcs(struct iio_dev *indio_dev)
{
	indio_dev->ring->preenable = &sca3000_hw_ring_preenable;
	indio_dev->ring->postdisable = &sca3000_hw_ring_postdisable;
}

/**
 * sca3000_ring_int_process() ring specific interrupt handling.
 *
 * This is only split from the main interrupt handler so as to
 * reduce the amount of code if the ring buffer is not enabled.
 **/
void sca3000_ring_int_process(u8 val, struct iio_ring_buffer *ring)
{
	if (val & SCA3000_INT_STATUS_THREE_QUARTERS)
		iio_push_or_escallate_ring_event(ring,
						 IIO_EVENT_CODE_RING_75_FULL,
						 0);
	else if (val & SCA3000_INT_STATUS_HALF)
		iio_push_ring_event(ring,
				    IIO_EVENT_CODE_RING_50_FULL, 0);
}
Commit	Line	Data
574fb258 JC	1	/*
	2	* sca3000_ring.c -- support VTI sca3000 series accelerometers via SPI
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU General Public License version 2 as published by
	6	* the Free Software Foundation.
	7	*
	8	* Copyright (c) 2009 Jonathan Cameron <jic23@cam.ac.uk>
	9	*
	10	*/
	11
	12	#include <linux/interrupt.h>
	13	#include <linux/gpio.h>
	14	#include <linux/fs.h>
	15	#include <linux/device.h>
5a0e3ad6	16	#include <linux/slab.h>
574fb258 JC	17	#include <linux/kernel.h>
	18	#include <linux/spi/spi.h>
	19	#include <linux/sysfs.h>
	20
	21	#include "../iio.h"
	22	#include "../sysfs.h"
	23	#include "../ring_generic.h"
	24	#include "../ring_hw.h"
	25	#include "accel.h"
	26	#include "sca3000.h"
	27
	28	/* RFC / future work
	29	*
	30	* The internal ring buffer doesn't actually change what it holds depending
	31	* on which signals are enabled etc, merely whether you can read them.
	32	* As such the scan mode selection is somewhat different than for a software
	33	* ring buffer and changing it actually covers any data already in the buffer.
	34	* Currently scan elements aren't configured so it doesn't matter.
	35	*/
	36
	37	/**
	38	* sca3000_rip_hw_rb() - main ring access function, pulls data from ring
	39	* @r: the ring
	40	* @count: number of samples to try and pull
	41	* @data: output the actual samples pulled from the hw ring
	42	* @dead_offset: cheating a bit here: Set to 1 so as to allow for the
	43	* leading byte used in bus comms.
	44	*
	45	* Currently does not provide timestamps. As the hardware doesn't add them they
	46	* can only be inferred aproximately from ring buffer events such as 50% full
	47	* and knowledge of when buffer was last emptied. This is left to userspace.
	48	**/
	49	static int sca3000_rip_hw_rb(struct iio_ring_buffer *r,
	50	size_t count, u8 *data, int dead_offset)
	51	{
	52	struct iio_hw_ring_buffer *hw_ring = iio_to_hw_ring_buf(r);
	53	struct iio_dev *indio_dev = hw_ring->private;
	54	struct sca3000_state *st = indio_dev->dev_data;
	55	u8 *rx;
	56	int ret, num_available, num_read = 0;
	57	int bytes_per_sample = 1;
	58
	59	if (st->bpse == 11)
	60	bytes_per_sample = 2;
	61
	62	mutex_lock(&st->lock);
	63	/* Check how much data is available:
	64	* RFC: Implement an ioctl to not bother checking whether there
	65	* is enough data in the ring? Afterall, if we are responding
	66	* to an interrupt we have a minimum content guaranteed so it
	67	* seems slight silly to waste time checking it is there.
	68	*/
	69	ret = sca3000_read_data(st,
	70	SCA3000_REG_ADDR_BUF_COUNT,
	71	&rx, 1);
	72	if (ret)
	73	goto error_ret;
	74	else
	75	num_available = rx[1];
	76	/* num_available is the total number of samples available
	77	* i.e. number of time points * number of channels.
	78	*/
	79	kfree(rx);
	80	if (count > num_available * bytes_per_sample)
81	num_read = num_available*bytes_per_sample;
82	else
83	num_read = count - (count % (bytes_per_sample));
84
85	/* Avoid the read request byte */
86	*dead_offset = 1;
87	ret = sca3000_read_data(st,
88	SCA3000_REG_ADDR_RING_OUT,
89	data, num_read);
90	error_ret:
91	mutex_unlock(&st->lock);
92
93	return ret ? ret : num_read;
94	}
95
96	/* This is only valid with all 3 elements enabled */
97	static int sca3000_ring_get_length(struct iio_ring_buffer *r)
98	{
99	return 64;
100	}
101
102	/* only valid if resolution is kept at 11bits */
ffcab07a	103	static int sca3000_ring_get_bytes_per_datum(struct iio_ring_buffer *r)
574fb258 JC	104	{
	105	return 6;
	106	}
	107	static void sca3000_ring_release(struct device *dev)
	108	{
	109	struct iio_ring_buffer *r = to_iio_ring_buffer(dev);
	110	kfree(iio_to_hw_ring_buf(r));
	111	}
	112
	113	static IIO_RING_ENABLE_ATTR;
ffcab07a	114	static IIO_RING_BYTES_PER_DATUM_ATTR;
574fb258 JC	115	static IIO_RING_LENGTH_ATTR;
	116
	117	/**
	118	* sca3000_show_ring_bpse() -sysfs function to query bits per sample from ring
	119	* @dev: ring buffer device
	120	* @attr: this device attribute
	121	* @buf: buffer to write to
	122	**/
	123	static ssize_t sca3000_show_ring_bpse(struct device *dev,
	124	struct device_attribute *attr,
	125	char *buf)
	126	{
	127	int len = 0, ret;
	128	u8 *rx;
b68d58a8 MS	129	struct iio_dev *indio_dev = dev_get_drvdata(dev);
b68d58a8 MS	130	struct sca3000_state *st = indio_dev->dev_data;
574fb258 JC	131
	132	mutex_lock(&st->lock);
	133	ret = sca3000_read_data(st, SCA3000_REG_ADDR_MODE, &rx, 1);
	134	if (ret)
	135	goto error_ret;
	136	len = sprintf(buf, "%d\n", (rx[1] & SCA3000_RING_BUF_8BIT) ? 8 : 11);
	137	kfree(rx);
	138	error_ret:
	139	mutex_unlock(&st->lock);
	140
	141	return ret ? ret : len;
	142	}
	143
	144	/**
	145	* sca3000_store_ring_bpse() - bits per scan element
	146	* @dev: ring buffer device
	147	* @attr: attribute called from
	148	* @buf: input from userspace
	149	* @len: length of input
	150	**/
	151	static ssize_t sca3000_store_ring_bpse(struct device *dev,
	152	struct device_attribute *attr,
	153	const char *buf,
	154	size_t len)
	155	{
b68d58a8 MS	156	struct iio_dev *indio_dev = dev_get_drvdata(dev);
b68d58a8 MS	157	struct sca3000_state *st = indio_dev->dev_data;
574fb258 JC	158	int ret;
	159	u8 *rx;
	160	long val;
	161	ret = strict_strtol(buf, 10, &val);
	162	if (ret)
	163	return ret;
	164
	165	mutex_lock(&st->lock);
	166
	167	ret = sca3000_read_data(st, SCA3000_REG_ADDR_MODE, &rx, 1);
	168	if (!ret)
	169	switch (val) {
	170	case 8:
	171	ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
	172	rx[1] \| SCA3000_RING_BUF_8BIT);
	173	st->bpse = 8;
	174	break;
	175	case 11:
	176	ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
	177	rx[1] & ~SCA3000_RING_BUF_8BIT);
	178	st->bpse = 11;
	179	break;
	180	default:
	181	ret = -EINVAL;
	182	break;
	183	}
	184	mutex_unlock(&st->lock);
	185
	186	return ret ? ret : len;
	187	}
	188
7cfce527 GKH	189	static IIO_SCAN_EL_C(accel_x, 0, 0, 0, NULL);
	190	static IIO_SCAN_EL_C(accel_y, 1, 0, 0, NULL);
	191	static IIO_SCAN_EL_C(accel_z, 2, 0, 0, NULL);
f3fb0011 JC	192	static IIO_CONST_ATTR(accel_precision_available, "8 11");
	193	static IIO_DEVICE_ATTR(accel_precision,
	194	S_IRUGO \| S_IWUSR,
	195	sca3000_show_ring_bpse,
	196	sca3000_store_ring_bpse,
	197	0);
574fb258	198
f3fb0011 JC	199	static struct attribute *sca3000_scan_el_attrs[] = {
	200	&iio_scan_el_accel_x.dev_attr.attr,
	201	&iio_scan_el_accel_y.dev_attr.attr,
	202	&iio_scan_el_accel_z.dev_attr.attr,
	203	&iio_const_attr_accel_precision_available.dev_attr.attr,
	204	&iio_dev_attr_accel_precision.dev_attr.attr,
	205	NULL
	206	};
	207
	208	static struct attribute_group sca3000_scan_el_group = {
	209	.attrs = sca3000_scan_el_attrs,
	210	.name = "scan_elements",
	211	};
574fb258 JC	212
	213	/*
	214	* Ring buffer attributes
	215	* This device is a bit unusual in that the sampling frequency and bpse
	216	* only apply to the ring buffer. At all times full rate and accuracy
	217	* is available via direct reading from registers.
	218	*/
f3fb0011	219	static struct attribute *sca3000_ring_attributes[] = {
574fb258	220	&dev_attr_length.attr,
ffcab07a MS	221	&dev_attr_bytes_per_datum.attr,
ffcab07a MS	222	&dev_attr_enable.attr,
574fb258 JC	223	NULL,
	224	};
	225
	226	static struct attribute_group sca3000_ring_attr = {
f3fb0011	227	.attrs = sca3000_ring_attributes,
574fb258 JC	228	};
574fb258 JC	229
3860dc82	230	static const struct attribute_group *sca3000_ring_attr_groups[] = {
574fb258 JC	231	&sca3000_ring_attr,
	232	NULL
	233	};
	234
	235	static struct device_type sca3000_ring_type = {
	236	.release = sca3000_ring_release,
	237	.groups = sca3000_ring_attr_groups,
	238	};
	239
	240	static struct iio_ring_buffer sca3000_rb_allocate(struct iio_dev indio_dev)
	241	{
	242	struct iio_ring_buffer *buf;
	243	struct iio_hw_ring_buffer *ring;
	244
	245	ring = kzalloc(sizeof *ring, GFP_KERNEL);
	246	if (!ring)
7cfce527	247	return NULL;
574fb258 JC	248	ring->private = indio_dev;
	249	buf = &ring->buf;
	250	iio_ring_buffer_init(buf, indio_dev);
	251	buf->dev.type = &sca3000_ring_type;
	252	device_initialize(&buf->dev);
	253	buf->dev.parent = &indio_dev->dev;
	254	dev_set_drvdata(&buf->dev, (void *)buf);
	255
	256	return buf;
	257	}
	258
	259	static inline void sca3000_rb_free(struct iio_ring_buffer *r)
	260	{
	261	if (r)
	262	iio_put_ring_buffer(r);
	263	}
	264
	265	int sca3000_configure_ring(struct iio_dev *indio_dev)
	266	{
	267	indio_dev->ring = sca3000_rb_allocate(indio_dev);
	268	if (indio_dev->ring == NULL)
	269	return -ENOMEM;
	270	indio_dev->modes \|= INDIO_RING_HARDWARE_BUFFER;
	271
bf32963c	272	indio_dev->ring->scan_el_attrs = &sca3000_scan_el_group;
574fb258 JC	273	indio_dev->ring->access.rip_lots = &sca3000_rip_hw_rb;
574fb258 JC	274	indio_dev->ring->access.get_length = &sca3000_ring_get_length;
ffcab07a	275	indio_dev->ring->access.get_bytes_per_datum = &sca3000_ring_get_bytes_per_datum;
574fb258 JC	276
	277	return 0;
	278	}
	279
	280	void sca3000_unconfigure_ring(struct iio_dev *indio_dev)
	281	{
	282	sca3000_rb_free(indio_dev->ring);
	283	}
	284
	285	static inline
	286	int __sca3000_hw_ring_state_set(struct iio_dev *indio_dev, bool state)
	287	{
	288	struct sca3000_state *st = indio_dev->dev_data;
	289	int ret;
	290	u8 *rx;
	291
	292	mutex_lock(&st->lock);
	293	ret = sca3000_read_data(st, SCA3000_REG_ADDR_MODE, &rx, 1);
	294	if (ret)
	295	goto error_ret;
	296	if (state) {
	297	printk(KERN_INFO "supposedly enabling ring buffer\n");
	298	ret = sca3000_write_reg(st,
	299	SCA3000_REG_ADDR_MODE,
	300	(rx[1] \| SCA3000_RING_BUF_ENABLE));
	301	} else
	302	ret = sca3000_write_reg(st,
	303	SCA3000_REG_ADDR_MODE,
	304	(rx[1] & ~SCA3000_RING_BUF_ENABLE));
	305	kfree(rx);
	306	error_ret:
	307	mutex_unlock(&st->lock);
	308
	309	return ret;
	310	}
	311	/**
	312	* sca3000_hw_ring_preenable() hw ring buffer preenable function
	313	*
	314	* Very simple enable function as the chip will allows normal reads
	315	* during ring buffer operation so as long as it is indeed running
	316	* before we notify the core, the precise ordering does not matter.
	317	**/
	318	static int sca3000_hw_ring_preenable(struct iio_dev *indio_dev)
	319	{
	320	return __sca3000_hw_ring_state_set(indio_dev, 1);
	321	}
	322
	323	static int sca3000_hw_ring_postdisable(struct iio_dev *indio_dev)
	324	{
	325	return __sca3000_hw_ring_state_set(indio_dev, 0);
	326	}
	327
	328	void sca3000_register_ring_funcs(struct iio_dev *indio_dev)
	329	{
	330	indio_dev->ring->preenable = &sca3000_hw_ring_preenable;
	331	indio_dev->ring->postdisable = &sca3000_hw_ring_postdisable;
	332	}
	333
	334	/**
	335	* sca3000_ring_int_process() ring specific interrupt handling.
	336	*
	337	* This is only split from the main interrupt handler so as to
	338	* reduce the amount of code if the ring buffer is not enabled.
	339	**/
340	void sca3000_ring_int_process(u8 val, struct iio_ring_buffer *ring)
341	{
342	if (val & SCA3000_INT_STATUS_THREE_QUARTERS)
343	iio_push_or_escallate_ring_event(ring,
344	IIO_EVENT_CODE_RING_75_FULL,
345	0);
346	else if (val & SCA3000_INT_STATUS_HALF)
347	iio_push_ring_event(ring,
348	IIO_EVENT_CODE_RING_50_FULL, 0);
349	}