2 * Copyright (C) 2010 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>
20 #include "../ring_generic.h"
21 #include "../ring_sw.h"
22 #include "../trigger_consumer.h"
26 int ad799x_single_channel_from_ring(struct ad799x_state *st, int channum)
28 struct iio_ring_buffer *ring = iio_priv_to_dev(st)->ring;
32 if (!(test_bit(channum, ring->scan_mask))) {
37 ring_data = kmalloc(ring->access->get_bytes_per_datum(ring),
39 if (ring_data == NULL) {
43 ret = ring->access->read_last(ring, (u8 *) ring_data);
45 goto error_free_ring_data;
46 /* Need a count of channels prior to this one */
47 count = bitmap_weight(ring->scan_mask, channum);
48 ret = be16_to_cpu(ring_data[count]);
57 * ad799x_ring_preenable() setup the parameters of the ring before enabling
59 * The complex nature of the setting of the nuber of bytes per datum is due
60 * to this driver currently ensuring that the timestamp is stored at an 8
63 static int ad799x_ring_preenable(struct iio_dev *indio_dev)
65 struct iio_ring_buffer *ring = indio_dev->ring;
66 struct ad799x_state *st = iio_priv(indio_dev);
69 * Need to figure out the current mode based upon the requested
70 * scan mask in iio_dev
73 if (st->id == ad7997 || st->id == ad7998)
74 ad7997_8_set_scan_mode(st, *ring->scan_mask);
76 st->d_size = ring->scan_count * 2;
78 if (ring->scan_timestamp) {
79 st->d_size += sizeof(s64);
81 if (st->d_size % sizeof(s64))
82 st->d_size += sizeof(s64) - (st->d_size % sizeof(s64));
85 if (indio_dev->ring->access->set_bytes_per_datum)
86 indio_dev->ring->access->set_bytes_per_datum(indio_dev->ring,
93 * ad799x_trigger_handler() bh of trigger launched polling to ring buffer
95 * Currently there is no option in this driver to disable the saving of
96 * timestamps within the ring.
99 static irqreturn_t ad799x_trigger_handler(int irq, void *p)
101 struct iio_poll_func *pf = p;
102 struct iio_dev *indio_dev = pf->indio_dev;
103 struct ad799x_state *st = iio_priv(indio_dev);
104 struct iio_ring_buffer *ring = indio_dev->ring;
110 rxbuf = kmalloc(st->d_size, GFP_KERNEL);
118 cmd = st->config | (*ring->scan_mask << AD799X_CHANNEL_SHIFT);
123 cmd = (*ring->scan_mask << AD799X_CHANNEL_SHIFT) |
128 cmd = AD7997_8_READ_SEQUENCE | AD7998_CONV_RES_REG;
134 b_sent = i2c_smbus_read_i2c_block_data(st->client,
135 cmd, ring->scan_count * 2, rxbuf);
139 time_ns = iio_get_time_ns();
141 if (ring->scan_timestamp)
142 memcpy(rxbuf + st->d_size - sizeof(s64),
143 &time_ns, sizeof(time_ns));
145 ring->access->store_to(indio_dev->ring, rxbuf, time_ns);
151 iio_trigger_notify_done(indio_dev->trig);
156 static const struct iio_ring_setup_ops ad799x_buf_setup_ops = {
157 .preenable = &ad799x_ring_preenable,
158 .postenable = &iio_triggered_buffer_postenable,
159 .predisable = &iio_triggered_buffer_predisable,
162 int ad799x_register_ring_funcs_and_init(struct iio_dev *indio_dev)
166 indio_dev->ring = iio_sw_rb_allocate(indio_dev);
167 if (!indio_dev->ring) {
171 /* Effectively select the ring buffer implementation */
172 indio_dev->ring->access = &ring_sw_access_funcs;
173 indio_dev->pollfunc = iio_alloc_pollfunc(NULL,
174 &ad799x_trigger_handler,
180 if (indio_dev->pollfunc == NULL) {
182 goto error_deallocate_sw_rb;
185 /* Ring buffer functions - here trigger setup related */
186 indio_dev->ring->setup_ops = &ad799x_buf_setup_ops;
187 indio_dev->ring->scan_timestamp = true;
189 /* Flag that polled ring buffering is possible */
190 indio_dev->modes |= INDIO_RING_TRIGGERED;
193 error_deallocate_sw_rb:
194 iio_sw_rb_free(indio_dev->ring);
199 void ad799x_ring_cleanup(struct iio_dev *indio_dev)
201 iio_dealloc_pollfunc(indio_dev->pollfunc);
202 iio_sw_rb_free(indio_dev->ring);