2 * Copyright (C) 2010-2012 Michael Hennerich, Analog Devices Inc.
3 * Copyright (C) 2008-2010 Jonathan Cameron
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
12 #include <linux/interrupt.h>
13 #include <linux/slab.h>
14 #include <linux/kernel.h>
15 #include <linux/list.h>
16 #include <linux/i2c.h>
17 #include <linux/bitops.h>
19 #include <linux/iio/iio.h>
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/kfifo_buf.h>
22 #include <linux/iio/trigger_consumer.h>
27 * ad799x_ring_preenable() setup the parameters of the ring before enabling
29 * The complex nature of the setting of the number of bytes per datum is due
30 * to this driver currently ensuring that the timestamp is stored at an 8
33 static int ad799x_ring_preenable(struct iio_dev *indio_dev)
35 struct ad799x_state *st = iio_priv(indio_dev);
37 * Need to figure out the current mode based upon the requested
38 * scan mask in iio_dev
41 if (st->id == ad7997 || st->id == ad7998)
42 ad7997_8_set_scan_mode(st, *indio_dev->active_scan_mask);
44 return iio_sw_buffer_preenable(indio_dev);
48 * ad799x_trigger_handler() bh of trigger launched polling to ring buffer
50 * Currently there is no option in this driver to disable the saving of
51 * timestamps within the ring.
54 static irqreturn_t ad799x_trigger_handler(int irq, void *p)
56 struct iio_poll_func *pf = p;
57 struct iio_dev *indio_dev = pf->indio_dev;
58 struct ad799x_state *st = iio_priv(indio_dev);
59 struct iio_buffer *ring = indio_dev->buffer;
65 rxbuf = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
74 (*indio_dev->active_scan_mask << AD799X_CHANNEL_SHIFT);
79 cmd = (*indio_dev->active_scan_mask << AD799X_CHANNEL_SHIFT) |
84 cmd = AD7997_8_READ_SEQUENCE | AD7998_CONV_RES_REG;
90 b_sent = i2c_smbus_read_i2c_block_data(st->client,
91 cmd, bitmap_weight(indio_dev->active_scan_mask,
92 indio_dev->masklength) * 2, rxbuf);
96 time_ns = iio_get_time_ns();
98 if (indio_dev->scan_timestamp)
99 memcpy(rxbuf + indio_dev->scan_bytes - sizeof(s64),
100 &time_ns, sizeof(time_ns));
102 ring->access->store_to(indio_dev->buffer, rxbuf, time_ns);
108 iio_trigger_notify_done(indio_dev->trig);
113 static const struct iio_buffer_setup_ops ad799x_buf_setup_ops = {
114 .preenable = &ad799x_ring_preenable,
115 .postenable = &iio_triggered_buffer_postenable,
116 .predisable = &iio_triggered_buffer_predisable,
119 int ad799x_register_ring_funcs_and_init(struct iio_dev *indio_dev)
123 indio_dev->buffer = iio_kfifo_allocate(indio_dev);
124 if (!indio_dev->buffer) {
128 indio_dev->pollfunc = iio_alloc_pollfunc(NULL,
129 &ad799x_trigger_handler,
135 if (indio_dev->pollfunc == NULL) {
137 goto error_deallocate_kfifo;
140 /* Ring buffer functions - here trigger setup related */
141 indio_dev->setup_ops = &ad799x_buf_setup_ops;
142 indio_dev->buffer->scan_timestamp = true;
144 /* Flag that polled ring buffering is possible */
145 indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
148 error_deallocate_kfifo:
149 iio_kfifo_free(indio_dev->buffer);
154 void ad799x_ring_cleanup(struct iio_dev *indio_dev)
156 iio_dealloc_pollfunc(indio_dev->pollfunc);
157 iio_kfifo_free(indio_dev->buffer);