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), GFP_KERNEL);
41 if (ring_data == NULL) {
45 ret = ring->access.read_last(ring, (u8 *) ring_data);
47 goto error_free_ring_data;
48 /* Need a count of channels prior to this one */
51 if (mask & ring->scan_mask)
56 ret = be16_to_cpu(ring_data[count]);
65 * ad799x_ring_preenable() setup the parameters of the ring before enabling
67 * The complex nature of the setting of the nuber of bytes per datum is due
68 * to this driver currently ensuring that the timestamp is stored at an 8
71 static int ad799x_ring_preenable(struct iio_dev *indio_dev)
73 struct iio_ring_buffer *ring = indio_dev->ring;
74 struct ad799x_state *st = iio_dev_get_devdata(indio_dev);
77 * Need to figure out the current mode based upon the requested
78 * scan mask in iio_dev
81 if (st->id == ad7997 || st->id == ad7998)
82 ad7997_8_set_scan_mode(st, ring->scan_mask);
84 st->d_size = ring->scan_count * 2;
86 if (ring->scan_timestamp) {
87 st->d_size += sizeof(s64);
89 if (st->d_size % sizeof(s64))
90 st->d_size += sizeof(s64) - (st->d_size % sizeof(s64));
93 if (indio_dev->ring->access.set_bytes_per_datum)
94 indio_dev->ring->access.set_bytes_per_datum(indio_dev->ring,
101 * ad799x_trigger_handler() bh of trigger launched polling to ring buffer
103 * Currently there is no option in this driver to disable the saving of
104 * timestamps within the ring.
107 static irqreturn_t ad799x_trigger_handler(int irq, void *p)
109 struct iio_poll_func *pf = p;
110 struct iio_dev *indio_dev = pf->private_data;
111 struct ad799x_state *st = iio_dev_get_devdata(indio_dev);
112 struct iio_ring_buffer *ring = indio_dev->ring;
113 struct iio_sw_ring_buffer *ring_sw = iio_to_sw_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(&ring_sw->buf, rxbuf, time_ns);
160 iio_trigger_notify_done(indio_dev->trig);
166 int ad799x_register_ring_funcs_and_init(struct iio_dev *indio_dev)
170 indio_dev->ring = iio_sw_rb_allocate(indio_dev);
171 if (!indio_dev->ring) {
175 /* Effectively select the ring buffer implementation */
176 iio_ring_sw_register_funcs(&indio_dev->ring->access);
177 indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
178 if (indio_dev->pollfunc == NULL) {
180 goto error_deallocate_sw_rb;
182 indio_dev->pollfunc->private_data = indio_dev;
183 indio_dev->pollfunc->thread = &ad799x_trigger_handler;
184 indio_dev->pollfunc->type = IRQF_ONESHOT;
185 indio_dev->pollfunc->name =
186 kasprintf(GFP_KERNEL, "%s_consumer%d", indio_dev->name,
188 if (indio_dev->pollfunc->name == NULL) {
190 goto error_free_poll_func;
192 /* Ring buffer functions - here trigger setup related */
194 indio_dev->ring->preenable = &ad799x_ring_preenable;
195 indio_dev->ring->postenable = &iio_triggered_ring_postenable;
196 indio_dev->ring->predisable = &iio_triggered_ring_predisable;
197 indio_dev->ring->scan_timestamp = true;
199 /* Flag that polled ring buffering is possible */
200 indio_dev->modes |= INDIO_RING_TRIGGERED;
202 error_free_poll_func:
203 kfree(indio_dev->pollfunc);
204 error_deallocate_sw_rb:
205 iio_sw_rb_free(indio_dev->ring);
210 void ad799x_ring_cleanup(struct iio_dev *indio_dev)
212 /* ensure that the trigger has been detached */
213 if (indio_dev->trig) {
214 iio_put_trigger(indio_dev->trig);
215 iio_trigger_dettach_poll_func(indio_dev->trig,
216 indio_dev->pollfunc);
218 kfree(indio_dev->pollfunc->name);
219 kfree(indio_dev->pollfunc);
220 iio_sw_rb_free(indio_dev->ring);