[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 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_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 + 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_poll_func_th() th of trigger launched polling to ring buffer
 *
 **/
static void ad7606_poll_func_th(struct iio_dev *indio_dev, s64 time)
{
	struct ad7606_state *st = indio_dev->dev_data;
	gpio_set_value(st->pdata->gpio_convst, 1);

	return;
}
/**
 * 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();
	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);
	ret = iio_alloc_pollfunc(indio_dev, NULL, &ad7606_poll_func_th);
	if (ret)
		goto error_deallocate_sw_rb;

	/* 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;

	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_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);
	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
	33	static ssize_t ad7606_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 ad7606_state *st = indio_dev->dev_data;
	40
	41	return sprintf(buf, "%c%d/%d\n", st->chip_info->sign,
	42	st->chip_info->bits, st->chip_info->bits);
	43	}
	44	static IIO_DEVICE_ATTR(in_type, S_IRUGO, ad7606_show_type, NULL, 0);
	45
	46	static struct attribute *ad7606_scan_el_attrs[] = {
	47	&iio_scan_el_in0.dev_attr.attr,
	48	&iio_const_attr_in0_index.dev_attr.attr,
	49	&iio_scan_el_in1.dev_attr.attr,
	50	&iio_const_attr_in1_index.dev_attr.attr,
	51	&iio_scan_el_in2.dev_attr.attr,
	52	&iio_const_attr_in2_index.dev_attr.attr,
	53	&iio_scan_el_in3.dev_attr.attr,
	54	&iio_const_attr_in3_index.dev_attr.attr,
	55	&iio_scan_el_in4.dev_attr.attr,
	56	&iio_const_attr_in4_index.dev_attr.attr,
	57	&iio_scan_el_in5.dev_attr.attr,
	58	&iio_const_attr_in5_index.dev_attr.attr,
	59	&iio_scan_el_in6.dev_attr.attr,
	60	&iio_const_attr_in6_index.dev_attr.attr,
	61	&iio_scan_el_in7.dev_attr.attr,
	62	&iio_const_attr_in7_index.dev_attr.attr,
	63	&iio_dev_attr_in_type.dev_attr.attr,
	64	NULL,
65	};
66
67	static mode_t ad7606_scan_el_attr_is_visible(struct kobject *kobj,
68	struct attribute *attr, int n)
69	{
70	struct device *dev = container_of(kobj, struct device, kobj);
71	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
72	struct iio_dev *indio_dev = ring->indio_dev;
73	struct ad7606_state *st = indio_dev->dev_data;
74
75	mode_t mode = attr->mode;
76
77	if (st->chip_info->num_channels <= 6 &&
78	(attr == &iio_scan_el_in7.dev_attr.attr \|\|
79	attr == &iio_const_attr_in7_index.dev_attr.attr \|\|
80	attr == &iio_scan_el_in6.dev_attr.attr \|\|
81	attr == &iio_const_attr_in6_index.dev_attr.attr))
82	mode = 0;
83	else if (st->chip_info->num_channels <= 4 &&
84	(attr == &iio_scan_el_in5.dev_attr.attr \|\|
85	attr == &iio_const_attr_in5_index.dev_attr.attr \|\|
86	attr == &iio_scan_el_in4.dev_attr.attr \|\|
87	attr == &iio_const_attr_in4_index.dev_attr.attr))
88	mode = 0;
89
90	return mode;
91	}
92
93	static struct attribute_group ad7606_scan_el_group = {
94	.name = "scan_elements",
95	.attrs = ad7606_scan_el_attrs,
96	.is_visible = ad7606_scan_el_attr_is_visible,
97	};
98
99	int ad7606_scan_from_ring(struct ad7606_state *st, unsigned ch)
100	{
101	struct iio_ring_buffer *ring = st->indio_dev->ring;
102	int ret;
103	u16 *ring_data;
104
105	ring_data = kmalloc(ring->access.get_bytes_per_datum(ring), GFP_KERNEL);
106	if (ring_data == NULL) {
107	ret = -ENOMEM;
108	goto error_ret;
109	}
110	ret = ring->access.read_last(ring, (u8 *) ring_data);
111	if (ret)
112	goto error_free_ring_data;
113
114	ret = ring_data[ch];
115
116	error_free_ring_data:
117	kfree(ring_data);
118	error_ret:
119	return ret;
120	}
121
122	/**
123	* ad7606_ring_preenable() setup the parameters of the ring before enabling
124	*
125	* The complex nature of the setting of the nuber of bytes per datum is due
126	* to this driver currently ensuring that the timestamp is stored at an 8
127	* byte boundary.
128	**/
129	static int ad7606_ring_preenable(struct iio_dev *indio_dev)
130	{
131	struct ad7606_state *st = indio_dev->dev_data;
132	struct iio_ring_buffer *ring = indio_dev->ring;
133	size_t d_size;
134
135	d_size = st->chip_info->num_channels *
136	st->chip_info->bits / 8 + sizeof(s64);
137
138	if (d_size % sizeof(s64))
139	d_size += sizeof(s64) - (d_size % sizeof(s64));
140
141	if (ring->access.set_bytes_per_datum)
142	ring->access.set_bytes_per_datum(ring, d_size);
143
144	st->d_size = d_size;
145
146	return 0;
147	}
148
149	/**
150	* ad7606_poll_func_th() th of trigger launched polling to ring buffer
151	*
152	**/
153	static void ad7606_poll_func_th(struct iio_dev *indio_dev, s64 time)
154	{
155	struct ad7606_state *st = indio_dev->dev_data;
156	gpio_set_value(st->pdata->gpio_convst, 1);
157
158	return;
159	}
160	/**
161	* ad7606_poll_bh_to_ring() bh of trigger launched polling to ring buffer
162	* @work_s: the work struct through which this was scheduled
163	*
164	* Currently there is no option in this driver to disable the saving of
165	* timestamps within the ring.
166	* I think the one copy of this at a time was to avoid problems if the
167	* trigger was set far too high and the reads then locked up the computer.
168	**/
169	static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
170	{
171	struct ad7606_state *st = container_of(work_s, struct ad7606_state,
172	poll_work);
173	struct iio_dev *indio_dev = st->indio_dev;
174	struct iio_sw_ring_buffer *sw_ring = iio_to_sw_ring(indio_dev->ring);
175	struct iio_ring_buffer *ring = indio_dev->ring;
176	s64 time_ns;
177	__u8 *buf;
178	int ret;
179
180	/* Ensure only one copy of this function running at a time */
181	if (atomic_inc_return(&st->protect_ring) > 1)
182	return;
183
184	buf = kzalloc(st->d_size, GFP_KERNEL);
185	if (buf == NULL)
186	return;
187
188	if (st->have_frstdata) {
189	ret = st->bops->read_block(st->dev, 1, buf);
190	if (ret)
191	goto done;
192	if (!gpio_get_value(st->pdata->gpio_frstdata)) {
193	/* This should never happen. However
194	* some signal glitch caused by bad PCB desgin or
195	* electrostatic discharge, could cause an extra read
196	* or clock. This allows recovery.
197	*/
198	ad7606_reset(st);
199	goto done;
200	}
201	ret = st->bops->read_block(st->dev,
202	st->chip_info->num_channels - 1, buf + 2);
203	if (ret)
204	goto done;
205	} else {
206	ret = st->bops->read_block(st->dev,
207	st->chip_info->num_channels, buf);
208	if (ret)
209	goto done;
210	}
211
212	time_ns = iio_get_time_ns();
213	memcpy(buf + st->d_size - sizeof(s64), &time_ns, sizeof(time_ns));
214
215	ring->access.store_to(&sw_ring->buf, buf, time_ns);
216	done:
217	gpio_set_value(st->pdata->gpio_convst, 0);
218	kfree(buf);
219	atomic_dec(&st->protect_ring);
220	}
221
222	int ad7606_register_ring_funcs_and_init(struct iio_dev *indio_dev)
223	{
224	struct ad7606_state *st = indio_dev->dev_data;
225	int ret;
226
227	indio_dev->ring = iio_sw_rb_allocate(indio_dev);
228	if (!indio_dev->ring) {
229	ret = -ENOMEM;
230	goto error_ret;
231	}
232
233	/* Effectively select the ring buffer implementation */
234	iio_ring_sw_register_funcs(&indio_dev->ring->access);
235	ret = iio_alloc_pollfunc(indio_dev, NULL, &ad7606_poll_func_th);
236	if (ret)
237	goto error_deallocate_sw_rb;
238
239	/* Ring buffer functions - here trigger setup related */
240
241	indio_dev->ring->preenable = &ad7606_ring_preenable;
242	indio_dev->ring->postenable = &iio_triggered_ring_postenable;
243	indio_dev->ring->predisable = &iio_triggered_ring_predisable;
244	indio_dev->ring->scan_el_attrs = &ad7606_scan_el_group;
245
246	INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring);
247
248	/* Flag that polled ring buffering is possible */
249	indio_dev->modes \|= INDIO_RING_TRIGGERED;
250	return 0;
251	error_deallocate_sw_rb:
252	iio_sw_rb_free(indio_dev->ring);
253	error_ret:
254	return ret;
255	}
256
257	void ad7606_ring_cleanup(struct iio_dev *indio_dev)
258	{
259	if (indio_dev->trig) {
260	iio_put_trigger(indio_dev->trig);
261	iio_trigger_dettach_poll_func(indio_dev->trig,
262	indio_dev->pollfunc);
263	}
264	kfree(indio_dev->pollfunc);
265	iio_sw_rb_free(indio_dev->ring);
266	}