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/workqueue.h>
14 #include <linux/device.h>
15 #include <linux/slab.h>
16 #include <linux/kernel.h>
17 #include <linux/sysfs.h>
18 #include <linux/list.h>
19 #include <linux/i2c.h>
20 #include <linux/bitops.h>
23 #include "../ring_generic.h"
24 #include "../ring_sw.h"
25 #include "../trigger.h"
30 int ad799x_single_channel_from_ring(struct ad799x_state
*st
, long mask
)
32 struct iio_ring_buffer
*ring
= st
->indio_dev
->ring
;
36 if (!(ring
->scan_mask
& mask
)) {
41 ring_data
= kmalloc(ring
->access
.get_bytes_per_datum(ring
), GFP_KERNEL
);
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
= indio_dev
->dev_data
;
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 ad799x_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_poll_func_th() th of trigger launched polling to ring buffer
104 * As sampling only occurs on i2c comms occuring, leave timestamping until
105 * then. Some triggers will generate their own time stamp. Currently
106 * there is no way of notifying them when no one cares.
108 static void ad799x_poll_func_th(struct iio_dev
*indio_dev
, s64 time
)
110 struct ad799x_state
*st
= indio_dev
->dev_data
;
112 schedule_work(&st
->poll_work
);
117 * ad799x_poll_bh_to_ring() bh of trigger launched polling to ring buffer
118 * @work_s: the work struct through which this was scheduled
120 * Currently there is no option in this driver to disable the saving of
121 * timestamps within the ring.
122 * I think the one copy of this at a time was to avoid problems if the
123 * trigger was set far too high and the reads then locked up the computer.
125 static void ad799x_poll_bh_to_ring(struct work_struct
*work_s
)
127 struct ad799x_state
*st
= container_of(work_s
, struct ad799x_state
,
129 struct iio_dev
*indio_dev
= st
->indio_dev
;
130 struct iio_ring_buffer
*ring
= indio_dev
->ring
;
131 struct iio_sw_ring_buffer
*ring_sw
= iio_to_sw_ring(indio_dev
->ring
);
137 /* Ensure only one copy of this function running at a time */
138 if (atomic_inc_return(&st
->protect_ring
) > 1)
141 rxbuf
= kmalloc(st
->d_size
, GFP_KERNEL
);
149 cmd
= st
->config
| (ring
->scan_mask
<< AD799X_CHANNEL_SHIFT
);
154 cmd
= (ring
->scan_mask
<< AD799X_CHANNEL_SHIFT
) |
159 cmd
= AD7997_8_READ_SEQUENCE
| AD7998_CONV_RES_REG
;
165 b_sent
= i2c_smbus_read_i2c_block_data(st
->client
,
166 cmd
, ring
->scan_count
* 2, rxbuf
);
170 time_ns
= iio_get_time_ns();
172 if (ring
->scan_timestamp
)
173 memcpy(rxbuf
+ st
->d_size
- sizeof(s64
),
174 &time_ns
, sizeof(time_ns
));
176 ring
->access
.store_to(&ring_sw
->buf
, rxbuf
, time_ns
);
179 atomic_dec(&st
->protect_ring
);
183 int ad799x_register_ring_funcs_and_init(struct iio_dev
*indio_dev
)
185 struct ad799x_state
*st
= indio_dev
->dev_data
;
188 indio_dev
->ring
= iio_sw_rb_allocate(indio_dev
);
189 if (!indio_dev
->ring
) {
193 /* Effectively select the ring buffer implementation */
194 iio_ring_sw_register_funcs(&st
->indio_dev
->ring
->access
);
195 ret
= iio_alloc_pollfunc(indio_dev
, NULL
, &ad799x_poll_func_th
);
197 goto error_deallocate_sw_rb
;
199 /* Ring buffer functions - here trigger setup related */
201 indio_dev
->ring
->preenable
= &ad799x_ring_preenable
;
202 indio_dev
->ring
->postenable
= &iio_triggered_ring_postenable
;
203 indio_dev
->ring
->predisable
= &iio_triggered_ring_predisable
;
204 indio_dev
->ring
->scan_timestamp
= true;
206 INIT_WORK(&st
->poll_work
, &ad799x_poll_bh_to_ring
);
208 indio_dev
->ring
->scan_el_attrs
= st
->chip_info
->scan_attrs
;
210 /* Flag that polled ring buffering is possible */
211 indio_dev
->modes
|= INDIO_RING_TRIGGERED
;
213 error_deallocate_sw_rb
:
214 iio_sw_rb_free(indio_dev
->ring
);
219 void ad799x_ring_cleanup(struct iio_dev
*indio_dev
)
221 /* ensure that the trigger has been detached */
222 if (indio_dev
->trig
) {
223 iio_put_trigger(indio_dev
->trig
);
224 iio_trigger_dettach_poll_func(indio_dev
->trig
,
225 indio_dev
->pollfunc
);
227 kfree(indio_dev
->pollfunc
);
228 iio_sw_rb_free(indio_dev
->ring
);