adis16203_ring.c revision c15c4f1dea101f14f54ee081f07dbdaf4fa74e19 
1#include <linux/export.h>
2#include <linux/interrupt.h>
3#include <linux/mutex.h>
4#include <linux/kernel.h>
5#include <linux/spi/spi.h>
6#include <linux/slab.h>
7
8#include "../iio.h"
9#include "../ring_sw.h"
10#include "../trigger_consumer.h"
11#include "adis16203.h"
12
13/**
14 * adis16203_read_ring_data() read data registers which will be placed into ring
15 * @dev: device associated with child of actual device (iio_dev or iio_trig)
16 * @rx: somewhere to pass back the value read
17 **/
18static int adis16203_read_ring_data(struct device *dev, u8 *rx)
19{
20	struct spi_message msg;
21	struct iio_dev *indio_dev = dev_get_drvdata(dev);
22	struct adis16203_state *st = iio_priv(indio_dev);
23	struct spi_transfer xfers[ADIS16203_OUTPUTS + 1];
24	int ret;
25	int i;
26
27	mutex_lock(&st->buf_lock);
28
29	spi_message_init(&msg);
30
31	memset(xfers, 0, sizeof(xfers));
32	for (i = 0; i <= ADIS16203_OUTPUTS; i++) {
33		xfers[i].bits_per_word = 8;
34		xfers[i].cs_change = 1;
35		xfers[i].len = 2;
36		xfers[i].delay_usecs = 20;
37		xfers[i].tx_buf = st->tx + 2 * i;
38		if (i < 1) /* SUPPLY_OUT: 0x02, AUX_ADC: 0x08 */
39			st->tx[2 * i] = ADIS16203_READ_REG(ADIS16203_SUPPLY_OUT + 2 * i);
40		else
41			st->tx[2 * i] = ADIS16203_READ_REG(ADIS16203_SUPPLY_OUT + 2 * i + 6);
42		st->tx[2 * i + 1] = 0;
43		if (i >= 1)
44			xfers[i].rx_buf = rx + 2 * (i - 1);
45		spi_message_add_tail(&xfers[i], &msg);
46	}
47
48	ret = spi_sync(st->us, &msg);
49	if (ret)
50		dev_err(&st->us->dev, "problem when burst reading");
51
52	mutex_unlock(&st->buf_lock);
53
54	return ret;
55}
56
57/* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
58 * specific to be rolled into the core.
59 */
60static irqreturn_t adis16203_trigger_handler(int irq, void *p)
61{
62	struct iio_poll_func *pf = p;
63	struct iio_dev *indio_dev = pf->indio_dev;
64	struct adis16203_state *st = iio_priv(indio_dev);
65	struct iio_buffer *ring = indio_dev->buffer;
66
67	int i = 0;
68	s16 *data;
69	size_t datasize = ring->access->get_bytes_per_datum(ring);
70
71	data = kmalloc(datasize, GFP_KERNEL);
72	if (data == NULL) {
73		dev_err(&st->us->dev, "memory alloc failed in ring bh");
74		return -ENOMEM;
75	}
76
77	if (ring->scan_count)
78		if (adis16203_read_ring_data(&indio_dev->dev, st->rx) >= 0)
79			for (; i < ring->scan_count; i++)
80				data[i] = be16_to_cpup(
81					(__be16 *)&(st->rx[i*2]));
82
83	/* Guaranteed to be aligned with 8 byte boundary */
84	if (ring->scan_timestamp)
85		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
86
87	ring->access->store_to(ring,
88			      (u8 *)data,
89			      pf->timestamp);
90
91	iio_trigger_notify_done(indio_dev->trig);
92	kfree(data);
93
94	return IRQ_HANDLED;
95}
96
97void adis16203_unconfigure_ring(struct iio_dev *indio_dev)
98{
99	iio_dealloc_pollfunc(indio_dev->pollfunc);
100	iio_sw_rb_free(indio_dev->buffer);
101}
102
103static const struct iio_buffer_setup_ops adis16203_ring_setup_ops = {
104	.preenable = &iio_sw_buffer_preenable,
105	.postenable = &iio_triggered_buffer_postenable,
106	.predisable = &iio_triggered_buffer_predisable,
107};
108
109int adis16203_configure_ring(struct iio_dev *indio_dev)
110{
111	int ret = 0;
112	struct iio_buffer *ring;
113
114	ring = iio_sw_rb_allocate(indio_dev);
115	if (!ring) {
116		ret = -ENOMEM;
117		return ret;
118	}
119	indio_dev->buffer = ring;
120	/* Effectively select the ring buffer implementation */
121	ring->scan_timestamp = true;
122	ring->access = &ring_sw_access_funcs;
123	ring->setup_ops = &adis16203_ring_setup_ops;
124	ring->owner = THIS_MODULE;
125
126	indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
127						 &adis16203_trigger_handler,
128						 IRQF_ONESHOT,
129						 indio_dev,
130						 "adis16203_consumer%d",
131						 indio_dev->id);
132	if (indio_dev->pollfunc == NULL) {
133		ret = -ENOMEM;
134		goto error_iio_sw_rb_free;
135	}
136
137	indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
138	return 0;
139
140error_iio_sw_rb_free:
141	iio_sw_rb_free(indio_dev->buffer);
142	return ret;
143}
144