[mirror_ubuntu-bionic-kernel.git] / drivers / staging / iio / adc / ad7887_ring.c

/*
 * Copyright 2010 Analog Devices Inc.
 * Copyright (C) 2008 Jonathan Cameron
 *
 * Licensed under the GPL-2 or later.
 *
 * ad7887_ring.c
 */

#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 <linux/list.h>
#include <linux/spi/spi.h>

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

#include "ad7887.h"

static IIO_SCAN_EL_C(in0, 0, 0, NULL);
static IIO_SCAN_EL_C(in1, 1, 0, NULL);
static IIO_SCAN_EL_TIMESTAMP(2);
static IIO_CONST_ATTR_SCAN_EL_TYPE(timestamp, s, 64, 64);

static ssize_t ad7887_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 ad7887_state *st = indio_dev->dev_data;

	return sprintf(buf, "%c%d/%d>>%d\n", st->chip_info->sign,
		       st->chip_info->bits, st->chip_info->storagebits,
		       st->chip_info->left_shift);
}
static IIO_DEVICE_ATTR(in_type, S_IRUGO, ad7887_show_type, NULL, 0);

static struct attribute *ad7887_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_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 ad7887_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 ad7887_state *st = indio_dev->dev_data;

	mode_t mode = attr->mode;

	if ((attr == &iio_scan_el_in1.dev_attr.attr) ||
		(attr == &iio_const_attr_in1_index.dev_attr.attr))
		if (!st->en_dual)
			mode = 0;

	return mode;
}

static struct attribute_group ad7887_scan_el_group = {
	.name = "scan_elements",
	.attrs = ad7887_scan_el_attrs,
	.is_visible = ad7887_scan_el_attr_is_visible,
};

int ad7887_scan_from_ring(struct ad7887_state *st, long mask)
{
	struct iio_ring_buffer *ring = st->indio_dev->ring;
	int count = 0, ret;
	u16 *ring_data;

	if (!(ring->scan_mask & mask)) {
		ret = -EBUSY;
		goto error_ret;
	}

	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;

	/* for single channel scan the result is stored with zero offset */
	if ((ring->scan_mask == ((1 << 1) | (1 << 0))) && (mask == (1 << 1)))
		count = 1;

	ret = be16_to_cpu(ring_data[count]);

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

/**
 * ad7887_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 ad7887_ring_preenable(struct iio_dev *indio_dev)
{
	struct ad7887_state *st = indio_dev->dev_data;
	struct iio_ring_buffer *ring = indio_dev->ring;

	st->d_size = ring->scan_count * st->chip_info->storagebits / 8;

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

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

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

	switch (ring->scan_mask) {
	case (1 << 0):
		st->ring_msg = &st->msg[AD7887_CH0];
		break;
	case (1 << 1):
		st->ring_msg = &st->msg[AD7887_CH1];
		/* Dummy read: push CH1 setting down to hardware */
		spi_sync(st->spi, st->ring_msg);
		break;
	case ((1 << 1) | (1 << 0)):
		st->ring_msg = &st->msg[AD7887_CH0_CH1];
		break;
	}

	return 0;
}

static int ad7887_ring_postdisable(struct iio_dev *indio_dev)
{
	struct ad7887_state *st = indio_dev->dev_data;

	/* dummy read: restore default CH0 settin */
	return spi_sync(st->spi, &st->msg[AD7887_CH0]);
}

/**
 * ad7887_poll_func_th() th of trigger launched polling to ring buffer
 *
 * As sampling only occurs on spi comms occurring, leave timestamping until
 * then.  Some triggers will generate their own time stamp.  Currently
 * there is no way of notifying them when no one cares.
 **/
static void ad7887_poll_func_th(struct iio_dev *indio_dev, s64 time)
{
	struct ad7887_state *st = indio_dev->dev_data;

	schedule_work(&st->poll_work);
	return;
}
/**
 * ad7887_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 ad7887_poll_bh_to_ring(struct work_struct *work_s)
{
	struct ad7887_state *st = container_of(work_s, struct ad7887_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 b_sent;

	unsigned int bytes = ring->scan_count * st->chip_info->storagebits / 8;

	/* 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;

	b_sent = spi_sync(st->spi, st->ring_msg);
	if (b_sent)
		goto done;

	time_ns = iio_get_time_ns();

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

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

int ad7887_register_ring_funcs_and_init(struct iio_dev *indio_dev)
{
	struct ad7887_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);
	ret = iio_alloc_pollfunc(indio_dev, NULL, &ad7887_poll_func_th);
	if (ret)
		goto error_deallocate_sw_rb;

	/* Ring buffer functions - here trigger setup related */

	indio_dev->ring->preenable = &ad7887_ring_preenable;
	indio_dev->ring->postenable = &iio_triggered_ring_postenable;
	indio_dev->ring->predisable = &iio_triggered_ring_predisable;
	indio_dev->ring->postdisable = &ad7887_ring_postdisable;
	indio_dev->ring->scan_el_attrs = &ad7887_scan_el_group;
	indio_dev->ring->scan_timestamp = true;

	INIT_WORK(&st->poll_work, &ad7887_poll_bh_to_ring);

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

void ad7887_ring_cleanup(struct iio_dev *indio_dev)
{
	/* ensure that the trigger has been detached */
	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);
	iio_sw_rb_free(indio_dev->ring);
}
Commit	Line	Data
2b4756aa MH	1	/*
	2	* Copyright 2010 Analog Devices Inc.
	3	* Copyright (C) 2008 Jonathan Cameron
	4	*
	5	* Licensed under the GPL-2 or later.
	6	*
	7	* ad7887_ring.c
	8	*/
	9
	10	#include <linux/interrupt.h>
	11	#include <linux/gpio.h>
	12	#include <linux/workqueue.h>
	13	#include <linux/device.h>
	14	#include <linux/kernel.h>
	15	#include <linux/slab.h>
	16	#include <linux/sysfs.h>
	17	#include <linux/list.h>
	18	#include <linux/spi/spi.h>
	19
	20	#include "../iio.h"
	21	#include "../ring_generic.h"
	22	#include "../ring_sw.h"
	23	#include "../trigger.h"
	24	#include "../sysfs.h"
	25
	26	#include "ad7887.h"
	27
	28	static IIO_SCAN_EL_C(in0, 0, 0, NULL);
	29	static IIO_SCAN_EL_C(in1, 1, 0, NULL);
e08d0265 MH	30	static IIO_SCAN_EL_TIMESTAMP(2);
e08d0265 MH	31	static IIO_CONST_ATTR_SCAN_EL_TYPE(timestamp, s, 64, 64);
2b4756aa MH	32
	33	static ssize_t ad7887_show_type(struct device *dev,
	34	struct device_attribute *attr,
	35	char *buf)
	36	{
	37	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	38	struct iio_dev *indio_dev = ring->indio_dev;
	39	struct ad7887_state *st = indio_dev->dev_data;
	40
	41	return sprintf(buf, "%c%d/%d>>%d\n", st->chip_info->sign,
	42	st->chip_info->bits, st->chip_info->storagebits,
	43	st->chip_info->left_shift);
	44	}
	45	static IIO_DEVICE_ATTR(in_type, S_IRUGO, ad7887_show_type, NULL, 0);
	46
	47	static struct attribute *ad7887_scan_el_attrs[] = {
	48	&iio_scan_el_in0.dev_attr.attr,
	49	&iio_const_attr_in0_index.dev_attr.attr,
	50	&iio_scan_el_in1.dev_attr.attr,
	51	&iio_const_attr_in1_index.dev_attr.attr,
e08d0265 MH	52	&iio_const_attr_timestamp_index.dev_attr.attr,
	53	&iio_scan_el_timestamp.dev_attr.attr,
	54	&iio_const_attr_timestamp_type.dev_attr.attr,
2b4756aa MH	55	&iio_dev_attr_in_type.dev_attr.attr,
	56	NULL,
	57	};
	58
	59	static mode_t ad7887_scan_el_attr_is_visible(struct kobject *kobj,
	60	struct attribute *attr, int n)
	61	{
	62	struct device *dev = container_of(kobj, struct device, kobj);
	63	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
	64	struct iio_dev *indio_dev = ring->indio_dev;
	65	struct ad7887_state *st = indio_dev->dev_data;
	66
	67	mode_t mode = attr->mode;
	68
	69	if ((attr == &iio_scan_el_in1.dev_attr.attr) \|\|
	70	(attr == &iio_const_attr_in1_index.dev_attr.attr))
	71	if (!st->en_dual)
	72	mode = 0;
	73
	74	return mode;
	75	}
	76
	77	static struct attribute_group ad7887_scan_el_group = {
	78	.name = "scan_elements",
	79	.attrs = ad7887_scan_el_attrs,
	80	.is_visible = ad7887_scan_el_attr_is_visible,
	81	};
	82
	83	int ad7887_scan_from_ring(struct ad7887_state *st, long mask)
	84	{
	85	struct iio_ring_buffer *ring = st->indio_dev->ring;
	86	int count = 0, ret;
	87	u16 *ring_data;
	88
	89	if (!(ring->scan_mask & mask)) {
	90	ret = -EBUSY;
	91	goto error_ret;
	92	}
	93
	94	ring_data = kmalloc(ring->access.get_bytes_per_datum(ring), GFP_KERNEL);
	95	if (ring_data == NULL) {
	96	ret = -ENOMEM;
	97	goto error_ret;
	98	}
	99	ret = ring->access.read_last(ring, (u8 *) ring_data);
	100	if (ret)
	101	goto error_free_ring_data;
	102
	103	/* for single channel scan the result is stored with zero offset */
	104	if ((ring->scan_mask == ((1 << 1) \| (1 << 0))) && (mask == (1 << 1)))
	105	count = 1;
	106
	107	ret = be16_to_cpu(ring_data[count]);
	108
	109	error_free_ring_data:
	110	kfree(ring_data);
	111	error_ret:
	112	return ret;
	113	}
	114
	115	/**
	116	* ad7887_ring_preenable() setup the parameters of the ring before enabling
	117	*
	118	* The complex nature of the setting of the nuber of bytes per datum is due
119	* to this driver currently ensuring that the timestamp is stored at an 8
120	* byte boundary.
121	**/
122	static int ad7887_ring_preenable(struct iio_dev *indio_dev)
123	{
124	struct ad7887_state *st = indio_dev->dev_data;
125	struct iio_ring_buffer *ring = indio_dev->ring;
2b4756aa	126
e08d0265 MH	127	st->d_size = ring->scan_count * st->chip_info->storagebits / 8;
	128
	129	if (ring->scan_timestamp) {
	130	st->d_size += sizeof(s64);
	131
	132	if (st->d_size % sizeof(s64))
	133	st->d_size += sizeof(s64) - (st->d_size % sizeof(s64));
2b4756aa MH	134	}
2b4756aa MH	135
e08d0265 MH	136	if (indio_dev->ring->access.set_bytes_per_datum)
	137	indio_dev->ring->access.set_bytes_per_datum(indio_dev->ring,
	138	st->d_size);
	139
2b4756aa MH	140	switch (ring->scan_mask) {
	141	case (1 << 0):
	142	st->ring_msg = &st->msg[AD7887_CH0];
	143	break;
	144	case (1 << 1):
	145	st->ring_msg = &st->msg[AD7887_CH1];
	146	/* Dummy read: push CH1 setting down to hardware */
	147	spi_sync(st->spi, st->ring_msg);
	148	break;
	149	case ((1 << 1) \| (1 << 0)):
	150	st->ring_msg = &st->msg[AD7887_CH0_CH1];
	151	break;
	152	}
	153
	154	return 0;
	155	}
	156
	157	static int ad7887_ring_postdisable(struct iio_dev *indio_dev)
	158	{
	159	struct ad7887_state *st = indio_dev->dev_data;
	160
	161	/* dummy read: restore default CH0 settin */
	162	return spi_sync(st->spi, &st->msg[AD7887_CH0]);
	163	}
	164
	165	/**
	166	* ad7887_poll_func_th() th of trigger launched polling to ring buffer
	167	*
25985edc	168	* As sampling only occurs on spi comms occurring, leave timestamping until
2b4756aa MH	169	* then. Some triggers will generate their own time stamp. Currently
	170	* there is no way of notifying them when no one cares.
	171	**/
	172	static void ad7887_poll_func_th(struct iio_dev *indio_dev, s64 time)
	173	{
	174	struct ad7887_state *st = indio_dev->dev_data;
	175
	176	schedule_work(&st->poll_work);
	177	return;
	178	}
	179	/**
	180	* ad7887_poll_bh_to_ring() bh of trigger launched polling to ring buffer
	181	* @work_s: the work struct through which this was scheduled
	182	*
	183	* Currently there is no option in this driver to disable the saving of
	184	* timestamps within the ring.
	185	* I think the one copy of this at a time was to avoid problems if the
	186	* trigger was set far too high and the reads then locked up the computer.
	187	**/
	188	static void ad7887_poll_bh_to_ring(struct work_struct *work_s)
	189	{
	190	struct ad7887_state *st = container_of(work_s, struct ad7887_state,
	191	poll_work);
	192	struct iio_dev *indio_dev = st->indio_dev;
	193	struct iio_sw_ring_buffer *sw_ring = iio_to_sw_ring(indio_dev->ring);
	194	struct iio_ring_buffer *ring = indio_dev->ring;
	195	s64 time_ns;
	196	__u8 *buf;
	197	int b_sent;
2b4756aa MH	198
	199	unsigned int bytes = ring->scan_count * st->chip_info->storagebits / 8;
	200
2b4756aa MH	201	/* Ensure only one copy of this function running at a time */
	202	if (atomic_inc_return(&st->protect_ring) > 1)
	203	return;
	204
e08d0265	205	buf = kzalloc(st->d_size, GFP_KERNEL);
2b4756aa MH	206	if (buf == NULL)
	207	return;
	208
	209	b_sent = spi_sync(st->spi, st->ring_msg);
	210	if (b_sent)
	211	goto done;
	212
	213	time_ns = iio_get_time_ns();
	214
	215	memcpy(buf, st->data, bytes);
e08d0265 MH	216	if (ring->scan_timestamp)
	217	memcpy(buf + st->d_size - sizeof(s64),
	218	&time_ns, sizeof(time_ns));
2b4756aa MH	219
	220	indio_dev->ring->access.store_to(&sw_ring->buf, buf, time_ns);
	221	done:
	222	kfree(buf);
	223	atomic_dec(&st->protect_ring);
	224	}
	225
	226	int ad7887_register_ring_funcs_and_init(struct iio_dev *indio_dev)
	227	{
	228	struct ad7887_state *st = indio_dev->dev_data;
	229	int ret;
	230
	231	indio_dev->ring = iio_sw_rb_allocate(indio_dev);
	232	if (!indio_dev->ring) {
	233	ret = -ENOMEM;
	234	goto error_ret;
	235	}
	236	/* Effectively select the ring buffer implementation */
	237	iio_ring_sw_register_funcs(&indio_dev->ring->access);
	238	ret = iio_alloc_pollfunc(indio_dev, NULL, &ad7887_poll_func_th);
	239	if (ret)
	240	goto error_deallocate_sw_rb;
	241
	242	/* Ring buffer functions - here trigger setup related */
	243
	244	indio_dev->ring->preenable = &ad7887_ring_preenable;
	245	indio_dev->ring->postenable = &iio_triggered_ring_postenable;
	246	indio_dev->ring->predisable = &iio_triggered_ring_predisable;
	247	indio_dev->ring->postdisable = &ad7887_ring_postdisable;
	248	indio_dev->ring->scan_el_attrs = &ad7887_scan_el_group;
e08d0265	249	indio_dev->ring->scan_timestamp = true;
2b4756aa MH	250
	251	INIT_WORK(&st->poll_work, &ad7887_poll_bh_to_ring);
	252
	253	/* Flag that polled ring buffering is possible */
	254	indio_dev->modes \|= INDIO_RING_TRIGGERED;
	255	return 0;
	256	error_deallocate_sw_rb:
	257	iio_sw_rb_free(indio_dev->ring);
	258	error_ret:
	259	return ret;
	260	}
	261
	262	void ad7887_ring_cleanup(struct iio_dev *indio_dev)
	263	{
	264	/* ensure that the trigger has been detached */
	265	if (indio_dev->trig) {
	266	iio_put_trigger(indio_dev->trig);
	267	iio_trigger_dettach_poll_func(indio_dev->trig,
	268	indio_dev->pollfunc);
	269	}
	270	kfree(indio_dev->pollfunc);
	271	iio_sw_rb_free(indio_dev->ring);
	272	}