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>
13 #include <linux/sysfs.h>
16 #include "../ring_generic.h"
17 #include "../ring_sw.h"
18 #include "../trigger.h"
23 int ad7606_scan_from_ring(struct iio_dev *indio_dev, unsigned ch)
25 struct iio_ring_buffer *ring = indio_dev->ring;
29 ring_data = kmalloc(ring->access->get_bytes_per_datum(ring),
31 if (ring_data == NULL) {
35 ret = ring->access->read_last(ring, (u8 *) ring_data);
37 goto error_free_ring_data;
48 * ad7606_ring_preenable() setup the parameters of the ring before enabling
50 * The complex nature of the setting of the nuber of bytes per datum is due
51 * to this driver currently ensuring that the timestamp is stored at an 8
54 static int ad7606_ring_preenable(struct iio_dev *indio_dev)
56 struct ad7606_state *st = iio_priv(indio_dev);
57 struct iio_ring_buffer *ring = indio_dev->ring;
60 d_size = st->chip_info->num_channels *
61 st->chip_info->channels[0].scan_type.storagebits / 8;
63 if (ring->scan_timestamp) {
64 d_size += sizeof(s64);
66 if (d_size % sizeof(s64))
67 d_size += sizeof(s64) - (d_size % sizeof(s64));
70 if (ring->access->set_bytes_per_datum)
71 ring->access->set_bytes_per_datum(ring, d_size);
79 * ad7606_trigger_handler_th() th/bh of trigger launched polling to ring buffer
82 static irqreturn_t ad7606_trigger_handler_th_bh(int irq, void *p)
84 struct iio_poll_func *pf = p;
85 struct iio_dev *indio_dev = pf->private_data;
86 struct ad7606_state *st = iio_priv(indio_dev);
88 gpio_set_value(st->pdata->gpio_convst, 1);
94 * ad7606_poll_bh_to_ring() bh of trigger launched polling to ring buffer
95 * @work_s: the work struct through which this was scheduled
97 * Currently there is no option in this driver to disable the saving of
98 * timestamps within the ring.
99 * I think the one copy of this at a time was to avoid problems if the
100 * trigger was set far too high and the reads then locked up the computer.
102 static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
104 struct ad7606_state *st = container_of(work_s, struct ad7606_state,
106 struct iio_dev *indio_dev = iio_priv_to_dev(st);
107 struct iio_ring_buffer *ring = indio_dev->ring;
112 buf = kzalloc(st->d_size, GFP_KERNEL);
116 if (st->have_frstdata) {
117 ret = st->bops->read_block(st->dev, 1, buf);
120 if (!gpio_get_value(st->pdata->gpio_frstdata)) {
121 /* This should never happen. However
122 * some signal glitch caused by bad PCB desgin or
123 * electrostatic discharge, could cause an extra read
124 * or clock. This allows recovery.
129 ret = st->bops->read_block(st->dev,
130 st->chip_info->num_channels - 1, buf + 2);
134 ret = st->bops->read_block(st->dev,
135 st->chip_info->num_channels, buf);
140 time_ns = iio_get_time_ns();
142 if (ring->scan_timestamp)
143 memcpy(buf + st->d_size - sizeof(s64),
144 &time_ns, sizeof(time_ns));
146 ring->access->store_to(indio_dev->ring, buf, time_ns);
148 gpio_set_value(st->pdata->gpio_convst, 0);
149 iio_trigger_notify_done(indio_dev->trig);
153 static const struct iio_ring_setup_ops ad7606_ring_setup_ops = {
154 .preenable = &ad7606_ring_preenable,
155 .postenable = &iio_triggered_ring_postenable,
156 .predisable = &iio_triggered_ring_predisable,
159 int ad7606_register_ring_funcs_and_init(struct iio_dev *indio_dev)
161 struct ad7606_state *st = iio_priv(indio_dev);
164 indio_dev->ring = iio_sw_rb_allocate(indio_dev);
165 if (!indio_dev->ring) {
170 /* Effectively select the ring buffer implementation */
171 indio_dev->ring->access = &ring_sw_access_funcs;
172 indio_dev->pollfunc = iio_alloc_pollfunc(&ad7606_trigger_handler_th_bh,
173 &ad7606_trigger_handler_th_bh,
179 if (indio_dev->pollfunc == NULL) {
181 goto error_deallocate_sw_rb;
184 /* Ring buffer functions - here trigger setup related */
186 indio_dev->ring->setup_ops = &ad7606_ring_setup_ops;
187 indio_dev->ring->scan_timestamp = true ;
189 INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring);
191 /* Flag that polled ring buffering is possible */
192 indio_dev->modes |= INDIO_RING_TRIGGERED;
195 error_deallocate_sw_rb:
196 iio_sw_rb_free(indio_dev->ring);
201 void ad7606_ring_cleanup(struct iio_dev *indio_dev)
203 if (indio_dev->trig) {
204 iio_put_trigger(indio_dev->trig);
205 iio_trigger_dettach_poll_func(indio_dev->trig,
206 indio_dev->pollfunc);
208 iio_dealloc_pollfunc(indio_dev->pollfunc);
209 iio_sw_rb_free(indio_dev->ring);