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>
14 #include <linux/iio/iio.h>
15 #include <linux/iio/buffer.h>
16 #include "../ring_sw.h"
17 #include <linux/iio/trigger_consumer.h>
22 * ad7606_trigger_handler_th() th/bh of trigger launched polling to ring buffer
25 static irqreturn_t ad7606_trigger_handler_th_bh(int irq, void *p)
27 struct iio_poll_func *pf = p;
28 struct ad7606_state *st = iio_priv(pf->indio_dev);
30 gpio_set_value(st->pdata->gpio_convst, 1);
36 * ad7606_poll_bh_to_ring() bh of trigger launched polling to ring buffer
37 * @work_s: the work struct through which this was scheduled
39 * Currently there is no option in this driver to disable the saving of
40 * timestamps within the ring.
41 * I think the one copy of this at a time was to avoid problems if the
42 * trigger was set far too high and the reads then locked up the computer.
44 static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
46 struct ad7606_state *st = container_of(work_s, struct ad7606_state,
48 struct iio_dev *indio_dev = iio_priv_to_dev(st);
49 struct iio_buffer *ring = indio_dev->buffer;
54 buf = kzalloc(indio_dev->scan_bytes, GFP_KERNEL);
58 if (gpio_is_valid(st->pdata->gpio_frstdata)) {
59 ret = st->bops->read_block(st->dev, 1, buf);
62 if (!gpio_get_value(st->pdata->gpio_frstdata)) {
63 /* This should never happen. However
64 * some signal glitch caused by bad PCB desgin or
65 * electrostatic discharge, could cause an extra read
66 * or clock. This allows recovery.
71 ret = st->bops->read_block(st->dev,
72 st->chip_info->num_channels - 1, buf + 2);
76 ret = st->bops->read_block(st->dev,
77 st->chip_info->num_channels, buf);
82 time_ns = iio_get_time_ns();
84 if (indio_dev->scan_timestamp)
85 *((s64 *)(buf + indio_dev->scan_bytes - sizeof(s64))) = time_ns;
87 ring->access->store_to(indio_dev->buffer, buf, time_ns);
89 gpio_set_value(st->pdata->gpio_convst, 0);
90 iio_trigger_notify_done(indio_dev->trig);
94 static const struct iio_buffer_setup_ops ad7606_ring_setup_ops = {
95 .preenable = &iio_sw_buffer_preenable,
96 .postenable = &iio_triggered_buffer_postenable,
97 .predisable = &iio_triggered_buffer_predisable,
100 int ad7606_register_ring_funcs_and_init(struct iio_dev *indio_dev)
102 struct ad7606_state *st = iio_priv(indio_dev);
105 indio_dev->buffer = iio_sw_rb_allocate(indio_dev);
106 if (!indio_dev->buffer) {
111 indio_dev->pollfunc = iio_alloc_pollfunc(&ad7606_trigger_handler_th_bh,
112 &ad7606_trigger_handler_th_bh,
118 if (indio_dev->pollfunc == NULL) {
120 goto error_deallocate_sw_rb;
123 /* Ring buffer functions - here trigger setup related */
125 indio_dev->setup_ops = &ad7606_ring_setup_ops;
126 indio_dev->buffer->scan_timestamp = true ;
128 INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring);
130 /* Flag that polled ring buffering is possible */
131 indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
134 error_deallocate_sw_rb:
135 iio_sw_rb_free(indio_dev->buffer);
140 void ad7606_ring_cleanup(struct iio_dev *indio_dev)
142 iio_dealloc_pollfunc(indio_dev->pollfunc);
143 iio_sw_rb_free(indio_dev->buffer);