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/device.h>
14 #include <linux/slab.h>
15 #include <linux/kernel.h>
16 #include <linux/sysfs.h>
17 #include <linux/list.h>
18 #include <linux/i2c.h>
19 #include <linux/bitops.h>
22 #include "../ring_generic.h"
23 #include "../ring_sw.h"
24 #include "../trigger.h"
29 int ad799x_single_channel_from_ring(struct ad799x_state *st, long mask)
31 struct iio_ring_buffer *ring = iio_priv_to_dev(st)->ring;
35 if (!(ring->scan_mask & mask)) {
40 ring_data = kmalloc(ring->access->get_bytes_per_datum(ring),
42 if (ring_data == NULL) {
46 ret = ring->access->read_last(ring, (u8 *) ring_data);
48 goto error_free_ring_data;
49 /* Need a count of channels prior to this one */
52 if (mask & ring->scan_mask)
57 ret = be16_to_cpu(ring_data[count]);
66 * ad799x_ring_preenable() setup the parameters of the ring before enabling
68 * The complex nature of the setting of the nuber of bytes per datum is due
69 * to this driver currently ensuring that the timestamp is stored at an 8
72 static int ad799x_ring_preenable(struct iio_dev *indio_dev)
74 struct iio_ring_buffer *ring = indio_dev->ring;
75 struct ad799x_state *st = iio_priv(indio_dev);
78 * Need to figure out the current mode based upon the requested
79 * scan mask in iio_dev
82 if (st->id == ad7997 || st->id == ad7998)
83 ad7997_8_set_scan_mode(st, ring->scan_mask);
85 st->d_size = ring->scan_count * 2;
87 if (ring->scan_timestamp) {
88 st->d_size += sizeof(s64);
90 if (st->d_size % sizeof(s64))
91 st->d_size += sizeof(s64) - (st->d_size % sizeof(s64));
94 if (indio_dev->ring->access->set_bytes_per_datum)
95 indio_dev->ring->access->set_bytes_per_datum(indio_dev->ring,
102 * ad799x_trigger_handler() bh of trigger launched polling to ring buffer
104 * Currently there is no option in this driver to disable the saving of
105 * timestamps within the ring.
108 static irqreturn_t ad799x_trigger_handler(int irq, void *p)
110 struct iio_poll_func *pf = p;
111 struct iio_dev *indio_dev = pf->private_data;
112 struct ad799x_state *st = iio_priv(indio_dev);
113 struct iio_ring_buffer *ring = indio_dev->ring;
119 rxbuf = kmalloc(st->d_size, GFP_KERNEL);
127 cmd = st->config | (ring->scan_mask << AD799X_CHANNEL_SHIFT);
132 cmd = (ring->scan_mask << AD799X_CHANNEL_SHIFT) |
137 cmd = AD7997_8_READ_SEQUENCE | AD7998_CONV_RES_REG;
143 b_sent = i2c_smbus_read_i2c_block_data(st->client,
144 cmd, ring->scan_count * 2, rxbuf);
148 time_ns = iio_get_time_ns();
150 if (ring->scan_timestamp)
151 memcpy(rxbuf + st->d_size - sizeof(s64),
152 &time_ns, sizeof(time_ns));
154 ring->access->store_to(indio_dev->ring, rxbuf, time_ns);
160 iio_trigger_notify_done(indio_dev->trig);
165 static const struct iio_ring_setup_ops ad799x_buf_setup_ops = {
166 .preenable = &ad799x_ring_preenable,
167 .postenable = &iio_triggered_ring_postenable,
168 .predisable = &iio_triggered_ring_predisable,
171 int ad799x_register_ring_funcs_and_init(struct iio_dev *indio_dev)
175 indio_dev->ring = iio_sw_rb_allocate(indio_dev);
176 if (!indio_dev->ring) {
180 /* Effectively select the ring buffer implementation */
181 indio_dev->ring->access = &ring_sw_access_funcs;
182 indio_dev->pollfunc = iio_alloc_pollfunc(NULL,
183 &ad799x_trigger_handler,
189 if (indio_dev->pollfunc == NULL) {
191 goto error_deallocate_sw_rb;
194 /* Ring buffer functions - here trigger setup related */
195 indio_dev->ring->setup_ops = &ad799x_buf_setup_ops;
196 indio_dev->ring->scan_timestamp = true;
198 /* Flag that polled ring buffering is possible */
199 indio_dev->modes |= INDIO_RING_TRIGGERED;
202 error_deallocate_sw_rb:
203 iio_sw_rb_free(indio_dev->ring);
208 void ad799x_ring_cleanup(struct iio_dev *indio_dev)
210 /* ensure that the trigger has been detached */
211 if (indio_dev->trig) {
212 iio_put_trigger(indio_dev->trig);
213 iio_trigger_dettach_poll_func(indio_dev->trig,
214 indio_dev->pollfunc);
216 iio_dealloc_pollfunc(indio_dev->pollfunc);
217 iio_sw_rb_free(indio_dev->ring);