[linux-2.6-block.git] / drivers / staging / iio / adc / ad7606_ring.c

/*
 * Copyright 2011 Analog Devices Inc.
 *
 * Licensed under the GPL-2.
 *
 */

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

#include "../iio.h"
#include "../ring_generic.h"
#include "../ring_sw.h"
#include "../trigger.h"
#include "../sysfs.h"

#include "ad7606.h"

static IIO_SCAN_EL_C(in0, 0, 0, NULL);
static IIO_SCAN_EL_C(in1, 1, 0, NULL);
static IIO_SCAN_EL_C(in2, 2, 0, NULL);
static IIO_SCAN_EL_C(in3, 3, 0, NULL);
static IIO_SCAN_EL_C(in4, 4, 0, NULL);
static IIO_SCAN_EL_C(in5, 5, 0, NULL);
static IIO_SCAN_EL_C(in6, 6, 0, NULL);
static IIO_SCAN_EL_C(in7, 7, 0, NULL);

static IIO_SCAN_EL_TIMESTAMP(8);
static IIO_CONST_ATTR_SCAN_EL_TYPE(timestamp, s, 64, 64);

static ssize_t ad7606_show_type(struct device *dev,
				struct device_attribute *attr,
				char *buf)
{
	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	struct iio_dev *indio_dev = ring->indio_dev;
	struct ad7606_state *st = indio_dev->dev_data;

	return sprintf(buf, "%c%d/%d\n", st->chip_info->sign,
		       st->chip_info->bits, st->chip_info->bits);
}
static IIO_DEVICE_ATTR(in_type, S_IRUGO, ad7606_show_type, NULL, 0);

static struct attribute *ad7606_scan_el_attrs[] = {
	&iio_scan_el_in0.dev_attr.attr,
	&iio_const_attr_in0_index.dev_attr.attr,
	&iio_scan_el_in1.dev_attr.attr,
	&iio_const_attr_in1_index.dev_attr.attr,
	&iio_scan_el_in2.dev_attr.attr,
	&iio_const_attr_in2_index.dev_attr.attr,
	&iio_scan_el_in3.dev_attr.attr,
	&iio_const_attr_in3_index.dev_attr.attr,
	&iio_scan_el_in4.dev_attr.attr,
	&iio_const_attr_in4_index.dev_attr.attr,
	&iio_scan_el_in5.dev_attr.attr,
	&iio_const_attr_in5_index.dev_attr.attr,
	&iio_scan_el_in6.dev_attr.attr,
	&iio_const_attr_in6_index.dev_attr.attr,
	&iio_scan_el_in7.dev_attr.attr,
	&iio_const_attr_in7_index.dev_attr.attr,
	&iio_const_attr_timestamp_index.dev_attr.attr,
	&iio_scan_el_timestamp.dev_attr.attr,
	&iio_const_attr_timestamp_type.dev_attr.attr,
	&iio_dev_attr_in_type.dev_attr.attr,
	NULL,
};

static mode_t ad7606_scan_el_attr_is_visible(struct kobject *kobj,
				     struct attribute *attr, int n)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	struct iio_dev *indio_dev = ring->indio_dev;
	struct ad7606_state *st = indio_dev->dev_data;

	mode_t mode = attr->mode;

	if (st->chip_info->num_channels <= 6 &&
		(attr == &iio_scan_el_in7.dev_attr.attr ||
		attr == &iio_const_attr_in7_index.dev_attr.attr ||
		attr == &iio_scan_el_in6.dev_attr.attr ||
		attr == &iio_const_attr_in6_index.dev_attr.attr))
		mode = 0;
	else if (st->chip_info->num_channels <= 4 &&
		(attr == &iio_scan_el_in5.dev_attr.attr ||
		attr == &iio_const_attr_in5_index.dev_attr.attr ||
		attr == &iio_scan_el_in4.dev_attr.attr ||
		attr == &iio_const_attr_in4_index.dev_attr.attr))
		mode = 0;

	return mode;
}

static struct attribute_group ad7606_scan_el_group = {
	.name = "scan_elements",
	.attrs = ad7606_scan_el_attrs,
	.is_visible = ad7606_scan_el_attr_is_visible,
};

int ad7606_scan_from_ring(struct ad7606_state *st, unsigned ch)
{
	struct iio_ring_buffer *ring = st->indio_dev->ring;
	int ret;
	u16 *ring_data;

	ring_data = kmalloc(ring->access.get_bytes_per_datum(ring), GFP_KERNEL);
	if (ring_data == NULL) {
		ret = -ENOMEM;
		goto error_ret;
	}
	ret = ring->access.read_last(ring, (u8 *) ring_data);
	if (ret)
		goto error_free_ring_data;

	ret = ring_data[ch];

error_free_ring_data:
	kfree(ring_data);
error_ret:
	return ret;
}

/**
 * ad7606_ring_preenable() setup the parameters of the ring before enabling
 *
 * The complex nature of the setting of the nuber of bytes per datum is due
 * to this driver currently ensuring that the timestamp is stored at an 8
 * byte boundary.
 **/
static int ad7606_ring_preenable(struct iio_dev *indio_dev)
{
	struct ad7606_state *st = indio_dev->dev_data;
	struct iio_ring_buffer *ring = indio_dev->ring;
	size_t d_size;

	d_size = st->chip_info->num_channels *
		 st->chip_info->bits / 8;

	if (ring->scan_timestamp) {
		d_size += sizeof(s64);

		if (d_size % sizeof(s64))
			d_size += sizeof(s64) - (d_size % sizeof(s64));
	}

	if (ring->access.set_bytes_per_datum)
		ring->access.set_bytes_per_datum(ring, d_size);

	st->d_size = d_size;

	return 0;
}

/**
 * ad7606_trigger_handler_th() th of trigger launched polling to ring buffer
 *
 **/
static irqreturn_t ad7606_trigger_handler_th(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->private_data;
	struct ad7606_state *st = indio_dev->dev_data;
	gpio_set_value(st->pdata->gpio_convst, 1);

	return IRQ_HANDLED;
}

/**
 * ad7606_poll_bh_to_ring() bh of trigger launched polling to ring buffer
 * @work_s:	the work struct through which this was scheduled
 *
 * Currently there is no option in this driver to disable the saving of
 * timestamps within the ring.
 * I think the one copy of this at a time was to avoid problems if the
 * trigger was set far too high and the reads then locked up the computer.
 **/
static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
{
	struct ad7606_state *st = container_of(work_s, struct ad7606_state,
						poll_work);
	struct iio_dev *indio_dev = st->indio_dev;
	struct iio_sw_ring_buffer *sw_ring = iio_to_sw_ring(indio_dev->ring);
	struct iio_ring_buffer *ring = indio_dev->ring;
	s64 time_ns;
	__u8 *buf;
	int ret;

	/* Ensure only one copy of this function running at a time */
	if (atomic_inc_return(&st->protect_ring) > 1)
		return;

	buf = kzalloc(st->d_size, GFP_KERNEL);
	if (buf == NULL)
		return;

	if (st->have_frstdata) {
		ret = st->bops->read_block(st->dev, 1, buf);
		if (ret)
			goto done;
		if (!gpio_get_value(st->pdata->gpio_frstdata)) {
			/* This should never happen. However
			 * some signal glitch caused by bad PCB desgin or
			 * electrostatic discharge, could cause an extra read
			 * or clock. This allows recovery.
			 */
			ad7606_reset(st);
			goto done;
		}
		ret = st->bops->read_block(st->dev,
			st->chip_info->num_channels - 1, buf + 2);
		if (ret)
			goto done;
	} else {
		ret = st->bops->read_block(st->dev,
			st->chip_info->num_channels, buf);
		if (ret)
			goto done;
	}

	time_ns = iio_get_time_ns();

	if (ring->scan_timestamp)
		memcpy(buf + st->d_size - sizeof(s64),
			&time_ns, sizeof(time_ns));

	ring->access.store_to(&sw_ring->buf, buf, time_ns);
done:
	gpio_set_value(st->pdata->gpio_convst, 0);
	kfree(buf);
	atomic_dec(&st->protect_ring);
}

int ad7606_register_ring_funcs_and_init(struct iio_dev *indio_dev)
{
	struct ad7606_state *st = indio_dev->dev_data;
	int ret;

	indio_dev->ring = iio_sw_rb_allocate(indio_dev);
	if (!indio_dev->ring) {
		ret = -ENOMEM;
		goto error_ret;
	}

	/* Effectively select the ring buffer implementation */
	iio_ring_sw_register_funcs(&indio_dev->ring->access);
	indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
	if (indio_dev->pollfunc == NULL) {
		ret = -ENOMEM;
		goto error_deallocate_sw_rb;
	}
	indio_dev->pollfunc->private_data = indio_dev;
	indio_dev->pollfunc->h = &ad7606_trigger_handler_th;
	indio_dev->pollfunc->name =
		kasprintf(GFP_KERNEL, "%s_consumer%d", indio_dev->name,
			  indio_dev->id);
	if (indio_dev->pollfunc->name == NULL) {
		ret = -ENOMEM;
		goto error_free_poll_func;
	}
	/* Ring buffer functions - here trigger setup related */

	indio_dev->ring->preenable = &ad7606_ring_preenable;
	indio_dev->ring->postenable = &iio_triggered_ring_postenable;
	indio_dev->ring->predisable = &iio_triggered_ring_predisable;
	indio_dev->ring->scan_el_attrs = &ad7606_scan_el_group;
	indio_dev->ring->scan_timestamp = true ;

	INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring);

	/* Flag that polled ring buffering is possible */
	indio_dev->modes |= INDIO_RING_TRIGGERED;
	return 0;
error_free_poll_func:
	kfree(indio_dev->pollfunc);
error_deallocate_sw_rb:
	iio_sw_rb_free(indio_dev->ring);
error_ret:
	return ret;
}

void ad7606_ring_cleanup(struct iio_dev *indio_dev)
{
	if (indio_dev->trig) {
		iio_put_trigger(indio_dev->trig);
		iio_trigger_dettach_poll_func(indio_dev->trig,
					      indio_dev->pollfunc);
	}
	kfree(indio_dev->pollfunc->name);
	kfree(indio_dev->pollfunc);
	iio_sw_rb_free(indio_dev->ring);
}
Commit	Line	Data
b9618c0c MH	1	/*
	2	* Copyright 2011 Analog Devices Inc.
	3	*
	4	* Licensed under the GPL-2.
	5	*
	6	*/
	7
	8	#include <linux/interrupt.h>
	9	#include <linux/gpio.h>
	10	#include <linux/workqueue.h>
	11	#include <linux/device.h>
	12	#include <linux/kernel.h>
	13	#include <linux/slab.h>
	14	#include <linux/sysfs.h>
	15
	16	#include "../iio.h"
	17	#include "../ring_generic.h"
	18	#include "../ring_sw.h"
	19	#include "../trigger.h"
	20	#include "../sysfs.h"
	21
	22	#include "ad7606.h"
	23
	24	static IIO_SCAN_EL_C(in0, 0, 0, NULL);
	25	static IIO_SCAN_EL_C(in1, 1, 0, NULL);
	26	static IIO_SCAN_EL_C(in2, 2, 0, NULL);
	27	static IIO_SCAN_EL_C(in3, 3, 0, NULL);
	28	static IIO_SCAN_EL_C(in4, 4, 0, NULL);
	29	static IIO_SCAN_EL_C(in5, 5, 0, NULL);
	30	static IIO_SCAN_EL_C(in6, 6, 0, NULL);
	31	static IIO_SCAN_EL_C(in7, 7, 0, NULL);
	32
dcfb0863 MH	33	static IIO_SCAN_EL_TIMESTAMP(8);
	34	static IIO_CONST_ATTR_SCAN_EL_TYPE(timestamp, s, 64, 64);
	35
b9618c0c MH	36	static ssize_t ad7606_show_type(struct device *dev,
	37	struct device_attribute *attr,
	38	char *buf)
	39	{
	40	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	41	struct iio_dev *indio_dev = ring->indio_dev;
	42	struct ad7606_state *st = indio_dev->dev_data;
	43
	44	return sprintf(buf, "%c%d/%d\n", st->chip_info->sign,
	45	st->chip_info->bits, st->chip_info->bits);
	46	}
	47	static IIO_DEVICE_ATTR(in_type, S_IRUGO, ad7606_show_type, NULL, 0);
	48
	49	static struct attribute *ad7606_scan_el_attrs[] = {
	50	&iio_scan_el_in0.dev_attr.attr,
	51	&iio_const_attr_in0_index.dev_attr.attr,
	52	&iio_scan_el_in1.dev_attr.attr,
	53	&iio_const_attr_in1_index.dev_attr.attr,
	54	&iio_scan_el_in2.dev_attr.attr,
	55	&iio_const_attr_in2_index.dev_attr.attr,
	56	&iio_scan_el_in3.dev_attr.attr,
	57	&iio_const_attr_in3_index.dev_attr.attr,
	58	&iio_scan_el_in4.dev_attr.attr,
	59	&iio_const_attr_in4_index.dev_attr.attr,
	60	&iio_scan_el_in5.dev_attr.attr,
	61	&iio_const_attr_in5_index.dev_attr.attr,
	62	&iio_scan_el_in6.dev_attr.attr,
	63	&iio_const_attr_in6_index.dev_attr.attr,
	64	&iio_scan_el_in7.dev_attr.attr,
	65	&iio_const_attr_in7_index.dev_attr.attr,
dcfb0863 MH	66	&iio_const_attr_timestamp_index.dev_attr.attr,
	67	&iio_scan_el_timestamp.dev_attr.attr,
	68	&iio_const_attr_timestamp_type.dev_attr.attr,
b9618c0c MH	69	&iio_dev_attr_in_type.dev_attr.attr,
	70	NULL,
	71	};
	72
	73	static mode_t ad7606_scan_el_attr_is_visible(struct kobject *kobj,
	74	struct attribute *attr, int n)
	75	{
	76	struct device *dev = container_of(kobj, struct device, kobj);
	77	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	78	struct iio_dev *indio_dev = ring->indio_dev;
	79	struct ad7606_state *st = indio_dev->dev_data;
	80
	81	mode_t mode = attr->mode;
	82
	83	if (st->chip_info->num_channels <= 6 &&
	84	(attr == &iio_scan_el_in7.dev_attr.attr \|\|
	85	attr == &iio_const_attr_in7_index.dev_attr.attr \|\|
	86	attr == &iio_scan_el_in6.dev_attr.attr \|\|
	87	attr == &iio_const_attr_in6_index.dev_attr.attr))
	88	mode = 0;
	89	else if (st->chip_info->num_channels <= 4 &&
	90	(attr == &iio_scan_el_in5.dev_attr.attr \|\|
	91	attr == &iio_const_attr_in5_index.dev_attr.attr \|\|
	92	attr == &iio_scan_el_in4.dev_attr.attr \|\|
	93	attr == &iio_const_attr_in4_index.dev_attr.attr))
	94	mode = 0;
	95
	96	return mode;
	97	}
	98
	99	static struct attribute_group ad7606_scan_el_group = {
	100	.name = "scan_elements",
	101	.attrs = ad7606_scan_el_attrs,
	102	.is_visible = ad7606_scan_el_attr_is_visible,
	103	};
	104
	105	int ad7606_scan_from_ring(struct ad7606_state *st, unsigned ch)
	106	{
	107	struct iio_ring_buffer *ring = st->indio_dev->ring;
	108	int ret;
	109	u16 *ring_data;
	110
	111	ring_data = kmalloc(ring->access.get_bytes_per_datum(ring), GFP_KERNEL);
	112	if (ring_data == NULL) {
	113	ret = -ENOMEM;
	114	goto error_ret;
	115	}
	116	ret = ring->access.read_last(ring, (u8 *) ring_data);
	117	if (ret)
	118	goto error_free_ring_data;
	119
	120	ret = ring_data[ch];
	121
	122	error_free_ring_data:
	123	kfree(ring_data);
	124	error_ret:
	125	return ret;
	126	}
	127
	128	/**
	129	* ad7606_ring_preenable() setup the parameters of the ring before enabling
	130	*
	131	* The complex nature of the setting of the nuber of bytes per datum is due
	132	* to this driver currently ensuring that the timestamp is stored at an 8
133	* byte boundary.
134	**/
135	static int ad7606_ring_preenable(struct iio_dev *indio_dev)
136	{
137	struct ad7606_state *st = indio_dev->dev_data;
138	struct iio_ring_buffer *ring = indio_dev->ring;
139	size_t d_size;
140
141	d_size = st->chip_info->num_channels *
dcfb0863 MH	142	st->chip_info->bits / 8;
	143
	144	if (ring->scan_timestamp) {
	145	d_size += sizeof(s64);
b9618c0c	146
dcfb0863 MH	147	if (d_size % sizeof(s64))
	148	d_size += sizeof(s64) - (d_size % sizeof(s64));
	149	}
b9618c0c MH	150
	151	if (ring->access.set_bytes_per_datum)
	152	ring->access.set_bytes_per_datum(ring, d_size);
	153
	154	st->d_size = d_size;
	155
	156	return 0;
	157	}
	158
	159	/**
13cfac20	160	* ad7606_trigger_handler_th() th of trigger launched polling to ring buffer
b9618c0c MH	161	*
b9618c0c MH	162	**/
13cfac20	163	static irqreturn_t ad7606_trigger_handler_th(int irq, void *p)
b9618c0c	164	{
13cfac20 JC	165	struct iio_poll_func *pf = p;
13cfac20 JC	166	struct iio_dev *indio_dev = pf->private_data;
b9618c0c MH	167	struct ad7606_state *st = indio_dev->dev_data;
	168	gpio_set_value(st->pdata->gpio_convst, 1);
	169
13cfac20	170	return IRQ_HANDLED;
b9618c0c	171	}
13cfac20	172
b9618c0c MH	173	/**
	174	* ad7606_poll_bh_to_ring() bh of trigger launched polling to ring buffer
	175	* @work_s: the work struct through which this was scheduled
	176	*
	177	* Currently there is no option in this driver to disable the saving of
	178	* timestamps within the ring.
	179	* I think the one copy of this at a time was to avoid problems if the
	180	* trigger was set far too high and the reads then locked up the computer.
	181	**/
	182	static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
	183	{
	184	struct ad7606_state *st = container_of(work_s, struct ad7606_state,
	185	poll_work);
	186	struct iio_dev *indio_dev = st->indio_dev;
	187	struct iio_sw_ring_buffer *sw_ring = iio_to_sw_ring(indio_dev->ring);
	188	struct iio_ring_buffer *ring = indio_dev->ring;
	189	s64 time_ns;
	190	__u8 *buf;
	191	int ret;
	192
	193	/* Ensure only one copy of this function running at a time */
	194	if (atomic_inc_return(&st->protect_ring) > 1)
	195	return;
	196
	197	buf = kzalloc(st->d_size, GFP_KERNEL);
	198	if (buf == NULL)
	199	return;
	200
	201	if (st->have_frstdata) {
	202	ret = st->bops->read_block(st->dev, 1, buf);
	203	if (ret)
	204	goto done;
	205	if (!gpio_get_value(st->pdata->gpio_frstdata)) {
	206	/* This should never happen. However
	207	* some signal glitch caused by bad PCB desgin or
	208	* electrostatic discharge, could cause an extra read
	209	* or clock. This allows recovery.
	210	*/
	211	ad7606_reset(st);
	212	goto done;
	213	}
	214	ret = st->bops->read_block(st->dev,
	215	st->chip_info->num_channels - 1, buf + 2);
	216	if (ret)
	217	goto done;
	218	} else {
	219	ret = st->bops->read_block(st->dev,
	220	st->chip_info->num_channels, buf);
	221	if (ret)
	222	goto done;
	223	}
	224
	225	time_ns = iio_get_time_ns();
dcfb0863 MH	226
	227	if (ring->scan_timestamp)
	228	memcpy(buf + st->d_size - sizeof(s64),
	229	&time_ns, sizeof(time_ns));
b9618c0c MH	230
	231	ring->access.store_to(&sw_ring->buf, buf, time_ns);
	232	done:
	233	gpio_set_value(st->pdata->gpio_convst, 0);
	234	kfree(buf);
	235	atomic_dec(&st->protect_ring);
	236	}
	237
	238	int ad7606_register_ring_funcs_and_init(struct iio_dev *indio_dev)
	239	{
	240	struct ad7606_state *st = indio_dev->dev_data;
	241	int ret;
	242
	243	indio_dev->ring = iio_sw_rb_allocate(indio_dev);
	244	if (!indio_dev->ring) {
	245	ret = -ENOMEM;
	246	goto error_ret;
	247	}
	248
	249	/* Effectively select the ring buffer implementation */
	250	iio_ring_sw_register_funcs(&indio_dev->ring->access);
13cfac20 JC	251	indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
	252	if (indio_dev->pollfunc == NULL) {
	253	ret = -ENOMEM;
b9618c0c	254	goto error_deallocate_sw_rb;
13cfac20 JC	255	}
	256	indio_dev->pollfunc->private_data = indio_dev;
	257	indio_dev->pollfunc->h = &ad7606_trigger_handler_th;
	258	indio_dev->pollfunc->name =
	259	kasprintf(GFP_KERNEL, "%s_consumer%d", indio_dev->name,
	260	indio_dev->id);
	261	if (indio_dev->pollfunc->name == NULL) {
	262	ret = -ENOMEM;
	263	goto error_free_poll_func;
	264	}
b9618c0c MH	265	/* Ring buffer functions - here trigger setup related */
	266
	267	indio_dev->ring->preenable = &ad7606_ring_preenable;
	268	indio_dev->ring->postenable = &iio_triggered_ring_postenable;
	269	indio_dev->ring->predisable = &iio_triggered_ring_predisable;
	270	indio_dev->ring->scan_el_attrs = &ad7606_scan_el_group;
dcfb0863	271	indio_dev->ring->scan_timestamp = true ;
b9618c0c MH	272
	273	INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring);
	274
	275	/* Flag that polled ring buffering is possible */
	276	indio_dev->modes \|= INDIO_RING_TRIGGERED;
	277	return 0;
13cfac20 JC	278	error_free_poll_func:
13cfac20 JC	279	kfree(indio_dev->pollfunc);
b9618c0c MH	280	error_deallocate_sw_rb:
	281	iio_sw_rb_free(indio_dev->ring);
	282	error_ret:
	283	return ret;
	284	}
	285
	286	void ad7606_ring_cleanup(struct iio_dev *indio_dev)
	287	{
	288	if (indio_dev->trig) {
	289	iio_put_trigger(indio_dev->trig);
	290	iio_trigger_dettach_poll_func(indio_dev->trig,
	291	indio_dev->pollfunc);
	292	}
13cfac20	293	kfree(indio_dev->pollfunc->name);
b9618c0c MH	294	kfree(indio_dev->pollfunc);
	295	iio_sw_rb_free(indio_dev->ring);
	296	}