2 * Copyright 2011 Analog Devices Inc.
4 * Licensed under the GPL-2.
8 #include <linux/interrupt.h>
9 #include <linux/gpio.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
15 #include "../buffer_generic.h"
16 #include "../ring_sw.h"
17 #include "../trigger_consumer.h"
21 int ad7606_scan_from_ring(struct iio_dev *indio_dev, unsigned ch)
23 struct iio_buffer *ring = indio_dev->buffer;
27 ring_data = kmalloc(ring->access->get_bytes_per_datum(ring),
29 if (ring_data == NULL) {
33 ret = ring->access->read_last(ring, (u8 *) ring_data);
35 goto error_free_ring_data;
46 * ad7606_ring_preenable() setup the parameters of the ring before enabling
48 * The complex nature of the setting of the nuber of bytes per datum is due
49 * to this driver currently ensuring that the timestamp is stored at an 8
52 static int ad7606_ring_preenable(struct iio_dev *indio_dev)
54 struct ad7606_state *st = iio_priv(indio_dev);
55 struct iio_buffer *ring = indio_dev->buffer;
58 d_size = st->chip_info->num_channels *
59 st->chip_info->channels[0].scan_type.storagebits / 8;
61 if (ring->scan_timestamp) {
62 d_size += sizeof(s64);
64 if (d_size % sizeof(s64))
65 d_size += sizeof(s64) - (d_size % sizeof(s64));
68 if (ring->access->set_bytes_per_datum)
69 ring->access->set_bytes_per_datum(ring, d_size);
77 * ad7606_trigger_handler_th() th/bh of trigger launched polling to ring buffer
80 static irqreturn_t ad7606_trigger_handler_th_bh(int irq, void *p)
82 struct iio_poll_func *pf = p;
83 struct ad7606_state *st = iio_priv(pf->indio_dev);
85 gpio_set_value(st->pdata->gpio_convst, 1);
91 * ad7606_poll_bh_to_ring() bh of trigger launched polling to ring buffer
92 * @work_s: the work struct through which this was scheduled
94 * Currently there is no option in this driver to disable the saving of
95 * timestamps within the ring.
96 * I think the one copy of this at a time was to avoid problems if the
97 * trigger was set far too high and the reads then locked up the computer.
99 static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
101 struct ad7606_state *st = container_of(work_s, struct ad7606_state,
103 struct iio_dev *indio_dev = iio_priv_to_dev(st);
104 struct iio_buffer *ring = indio_dev->buffer;
109 buf = kzalloc(st->d_size, GFP_KERNEL);
113 if (st->have_frstdata) {
114 ret = st->bops->read_block(st->dev, 1, buf);
117 if (!gpio_get_value(st->pdata->gpio_frstdata)) {
118 /* This should never happen. However
119 * some signal glitch caused by bad PCB desgin or
120 * electrostatic discharge, could cause an extra read
121 * or clock. This allows recovery.
126 ret = st->bops->read_block(st->dev,
127 st->chip_info->num_channels - 1, buf + 2);
131 ret = st->bops->read_block(st->dev,
132 st->chip_info->num_channels, buf);
137 time_ns = iio_get_time_ns();
139 if (ring->scan_timestamp)
140 memcpy(buf + st->d_size - sizeof(s64),
141 &time_ns, sizeof(time_ns));
143 ring->access->store_to(indio_dev->buffer, buf, time_ns);
145 gpio_set_value(st->pdata->gpio_convst, 0);
146 iio_trigger_notify_done(indio_dev->trig);
150 static const struct iio_buffer_setup_ops ad7606_ring_setup_ops = {
151 .preenable = &ad7606_ring_preenable,
152 .postenable = &iio_triggered_buffer_postenable,
153 .predisable = &iio_triggered_buffer_predisable,
156 int ad7606_register_ring_funcs_and_init(struct iio_dev *indio_dev)
158 struct ad7606_state *st = iio_priv(indio_dev);
161 indio_dev->buffer = iio_sw_rb_allocate(indio_dev);
162 if (!indio_dev->buffer) {
167 /* Effectively select the ring buffer implementation */
168 indio_dev->buffer->access = &ring_sw_access_funcs;
169 indio_dev->pollfunc = iio_alloc_pollfunc(&ad7606_trigger_handler_th_bh,
170 &ad7606_trigger_handler_th_bh,
176 if (indio_dev->pollfunc == NULL) {
178 goto error_deallocate_sw_rb;
181 /* Ring buffer functions - here trigger setup related */
183 indio_dev->buffer->setup_ops = &ad7606_ring_setup_ops;
184 indio_dev->buffer->scan_timestamp = true ;
186 INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring);
188 /* Flag that polled ring buffering is possible */
189 indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
192 error_deallocate_sw_rb:
193 iio_sw_rb_free(indio_dev->buffer);
198 void ad7606_ring_cleanup(struct iio_dev *indio_dev)
200 iio_dealloc_pollfunc(indio_dev->pollfunc);
201 iio_sw_rb_free(indio_dev->buffer);