2 * Copyright (C) 2008 Jonathan Cameron
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
11 #include <linux/interrupt.h>
12 #include <linux/gpio.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"
31 int max1363_single_channel_from_ring(long mask
, struct max1363_state
*st
)
33 unsigned long numvals
;
36 if (!(st
->current_mode
->modemask
& mask
)) {
40 numvals
= hweight_long(st
->current_mode
->modemask
);
42 ring_data
= kmalloc(numvals
*2, GFP_KERNEL
);
43 if (ring_data
== NULL
) {
47 ret
= st
->indio_dev
->ring
->access
.read_last(st
->indio_dev
->ring
,
50 goto error_free_ring_data
;
51 /* Need a count of channels prior to this one */
54 if (mask
& st
->current_mode
->modemask
)
58 if (st
->chip_info
->bits
!= 8)
59 ret
= ((int)(ring_data
[count
*2 + 0] & 0x0F) << 8)
60 + (int)(ring_data
[count
*2 + 1]);
62 ret
= ring_data
[count
];
71 * max1363_ring_preenable() - setup the parameters of the ring before enabling
73 * The complex nature of the setting of the nuber of bytes per datum is due
74 * to this driver currently ensuring that the timestamp is stored at an 8
77 static int max1363_ring_preenable(struct iio_dev
*indio_dev
)
79 struct max1363_state
*st
= indio_dev
->dev_data
;
81 unsigned long numvals
;
84 * Need to figure out the current mode based upon the requested
85 * scan mask in iio_dev
87 st
->current_mode
= max1363_match_mode(st
->indio_dev
->scan_mask
,
89 if (!st
->current_mode
)
92 max1363_set_scan_mode(st
);
94 numvals
= hweight_long(st
->current_mode
->modemask
);
95 if (indio_dev
->ring
->access
.set_bpd
) {
96 if (st
->chip_info
->bits
!= 8)
97 d_size
= numvals
*2 + sizeof(s64
);
99 d_size
= numvals
+ sizeof(s64
);
101 d_size
+= 8 - (d_size
% 8);
102 indio_dev
->ring
->access
.set_bpd(indio_dev
->ring
, d_size
);
110 * max1363_poll_func_th() - th of trigger launched polling to ring buffer
112 * As sampling only occurs on i2c comms occuring, leave timestamping until
113 * then. Some triggers will generate their own time stamp. Currently
114 * there is no way of notifying them when no one cares.
116 static void max1363_poll_func_th(struct iio_dev
*indio_dev
, s64 time
)
118 struct max1363_state
*st
= indio_dev
->dev_data
;
120 schedule_work(&st
->poll_work
);
125 * max1363_poll_bh_to_ring() - bh of trigger launched polling to ring buffer
126 * @work_s: the work struct through which this was scheduled
128 * Currently there is no option in this driver to disable the saving of
129 * timestamps within the ring.
130 * I think the one copy of this at a time was to avoid problems if the
131 * trigger was set far too high and the reads then locked up the computer.
133 static void max1363_poll_bh_to_ring(struct work_struct
*work_s
)
135 struct max1363_state
*st
= container_of(work_s
, struct max1363_state
,
137 struct iio_dev
*indio_dev
= st
->indio_dev
;
138 struct iio_sw_ring_buffer
*ring
= iio_to_sw_ring(indio_dev
->ring
);
143 unsigned long numvals
= hweight_long(st
->current_mode
->modemask
);
145 /* Ensure the timestamp is 8 byte aligned */
146 if (st
->chip_info
->bits
!= 8)
147 d_size
= numvals
*2 + sizeof(s64
);
149 d_size
= numvals
+ sizeof(s64
);
150 if (d_size
% sizeof(s64
))
151 d_size
+= sizeof(s64
) - (d_size
% sizeof(s64
));
153 /* Ensure only one copy of this function running at a time */
154 if (atomic_inc_return(&st
->protect_ring
) > 1)
157 /* Monitor mode prevents reading. Whilst not currently implemented
158 * might as well have this test in here in the meantime as it does
164 rxbuf
= kmalloc(d_size
, GFP_KERNEL
);
167 if (st
->chip_info
->bits
!= 8)
168 b_sent
= i2c_master_recv(st
->client
, rxbuf
, numvals
*2);
170 b_sent
= i2c_master_recv(st
->client
, rxbuf
, numvals
);
174 time_ns
= iio_get_time_ns();
176 memcpy(rxbuf
+ d_size
- sizeof(s64
), &time_ns
, sizeof(time_ns
));
178 indio_dev
->ring
->access
.store_to(&ring
->buf
, rxbuf
, time_ns
);
181 atomic_dec(&st
->protect_ring
);
185 int max1363_register_ring_funcs_and_init(struct iio_dev
*indio_dev
)
187 struct max1363_state
*st
= indio_dev
->dev_data
;
190 indio_dev
->ring
= iio_sw_rb_allocate(indio_dev
);
191 if (!indio_dev
->ring
) {
195 /* Effectively select the ring buffer implementation */
196 iio_ring_sw_register_funcs(&st
->indio_dev
->ring
->access
);
197 ret
= iio_alloc_pollfunc(indio_dev
, NULL
, &max1363_poll_func_th
);
199 goto error_deallocate_sw_rb
;
201 /* Ring buffer functions - here trigger setup related */
202 indio_dev
->ring
->postenable
= &iio_triggered_ring_postenable
;
203 indio_dev
->ring
->preenable
= &max1363_ring_preenable
;
204 indio_dev
->ring
->predisable
= &iio_triggered_ring_predisable
;
205 INIT_WORK(&st
->poll_work
, &max1363_poll_bh_to_ring
);
207 /* Flag that polled ring buffering is possible */
208 indio_dev
->modes
|= INDIO_RING_TRIGGERED
;
210 error_deallocate_sw_rb
:
211 iio_sw_rb_free(indio_dev
->ring
);
216 void max1363_ring_cleanup(struct iio_dev
*indio_dev
)
218 /* ensure that the trigger has been detached */
219 if (indio_dev
->trig
) {
220 iio_put_trigger(indio_dev
->trig
);
221 iio_trigger_dettach_poll_func(indio_dev
->trig
,
222 indio_dev
->pollfunc
);
224 kfree(indio_dev
->pollfunc
);
225 iio_sw_rb_free(indio_dev
->ring
);