2 * Copyright 2011 Analog Devices Inc.
4 * Licensed under the GPL-2.
8 #include <linux/interrupt.h>
9 #include <linux/gpio.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/sysfs.h>
16 #include "../ring_generic.h"
17 #include "../ring_sw.h"
18 #include "../trigger.h"
23 int ad7606_scan_from_ring(struct iio_dev
*indio_dev
, unsigned ch
)
25 struct iio_ring_buffer
*ring
= indio_dev
->ring
;
29 ring_data
= kmalloc(ring
->access
->get_bytes_per_datum(ring
),
31 if (ring_data
== NULL
) {
35 ret
= ring
->access
->read_last(ring
, (u8
*) ring_data
);
37 goto error_free_ring_data
;
48 * ad7606_ring_preenable() setup the parameters of the ring before enabling
50 * The complex nature of the setting of the nuber of bytes per datum is due
51 * to this driver currently ensuring that the timestamp is stored at an 8
54 static int ad7606_ring_preenable(struct iio_dev
*indio_dev
)
56 struct ad7606_state
*st
= iio_priv(indio_dev
);
57 struct iio_ring_buffer
*ring
= indio_dev
->ring
;
60 d_size
= st
->chip_info
->num_channels
*
61 st
->chip_info
->channels
[0].scan_type
.storagebits
/ 8;
63 if (ring
->scan_timestamp
) {
64 d_size
+= sizeof(s64
);
66 if (d_size
% sizeof(s64
))
67 d_size
+= sizeof(s64
) - (d_size
% sizeof(s64
));
70 if (ring
->access
->set_bytes_per_datum
)
71 ring
->access
->set_bytes_per_datum(ring
, d_size
);
79 * ad7606_trigger_handler_th() th/bh of trigger launched polling to ring buffer
82 static irqreturn_t
ad7606_trigger_handler_th_bh(int irq
, void *p
)
84 struct iio_poll_func
*pf
= p
;
85 struct iio_dev
*indio_dev
= pf
->private_data
;
86 struct ad7606_state
*st
= iio_priv(indio_dev
);
88 gpio_set_value(st
->pdata
->gpio_convst
, 1);
94 * ad7606_poll_bh_to_ring() bh of trigger launched polling to ring buffer
95 * @work_s: the work struct through which this was scheduled
97 * Currently there is no option in this driver to disable the saving of
98 * timestamps within the ring.
99 * I think the one copy of this at a time was to avoid problems if the
100 * trigger was set far too high and the reads then locked up the computer.
102 static void ad7606_poll_bh_to_ring(struct work_struct
*work_s
)
104 struct ad7606_state
*st
= container_of(work_s
, struct ad7606_state
,
106 struct iio_dev
*indio_dev
= iio_priv_to_dev(st
);
107 struct iio_ring_buffer
*ring
= indio_dev
->ring
;
112 buf
= kzalloc(st
->d_size
, GFP_KERNEL
);
116 if (st
->have_frstdata
) {
117 ret
= st
->bops
->read_block(st
->dev
, 1, buf
);
120 if (!gpio_get_value(st
->pdata
->gpio_frstdata
)) {
121 /* This should never happen. However
122 * some signal glitch caused by bad PCB desgin or
123 * electrostatic discharge, could cause an extra read
124 * or clock. This allows recovery.
129 ret
= st
->bops
->read_block(st
->dev
,
130 st
->chip_info
->num_channels
- 1, buf
+ 2);
134 ret
= st
->bops
->read_block(st
->dev
,
135 st
->chip_info
->num_channels
, buf
);
140 time_ns
= iio_get_time_ns();
142 if (ring
->scan_timestamp
)
143 memcpy(buf
+ st
->d_size
- sizeof(s64
),
144 &time_ns
, sizeof(time_ns
));
146 ring
->access
->store_to(indio_dev
->ring
, buf
, time_ns
);
148 gpio_set_value(st
->pdata
->gpio_convst
, 0);
149 iio_trigger_notify_done(indio_dev
->trig
);
153 static const struct iio_ring_setup_ops ad7606_ring_setup_ops
= {
154 .preenable
= &ad7606_ring_preenable
,
155 .postenable
= &iio_triggered_ring_postenable
,
156 .predisable
= &iio_triggered_ring_predisable
,
159 int ad7606_register_ring_funcs_and_init(struct iio_dev
*indio_dev
)
161 struct ad7606_state
*st
= iio_priv(indio_dev
);
164 indio_dev
->ring
= iio_sw_rb_allocate(indio_dev
);
165 if (!indio_dev
->ring
) {
170 /* Effectively select the ring buffer implementation */
171 indio_dev
->ring
->access
= &ring_sw_access_funcs
;
172 indio_dev
->pollfunc
= iio_alloc_pollfunc(&ad7606_trigger_handler_th_bh
,
173 &ad7606_trigger_handler_th_bh
,
179 if (indio_dev
->pollfunc
== NULL
) {
181 goto error_deallocate_sw_rb
;
184 /* Ring buffer functions - here trigger setup related */
186 indio_dev
->ring
->setup_ops
= &ad7606_ring_setup_ops
;
187 indio_dev
->ring
->scan_timestamp
= true ;
189 INIT_WORK(&st
->poll_work
, &ad7606_poll_bh_to_ring
);
191 /* Flag that polled ring buffering is possible */
192 indio_dev
->modes
|= INDIO_RING_TRIGGERED
;
195 error_deallocate_sw_rb
:
196 iio_sw_rb_free(indio_dev
->ring
);
201 void ad7606_ring_cleanup(struct iio_dev
*indio_dev
)
203 if (indio_dev
->trig
) {
204 iio_put_trigger(indio_dev
->trig
);
205 iio_trigger_dettach_poll_func(indio_dev
->trig
,
206 indio_dev
->pollfunc
);
208 iio_dealloc_pollfunc(indio_dev
->pollfunc
);
209 iio_sw_rb_free(indio_dev
->ring
);