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);
109 * max1363_ring_postenable() typical ring post enable
111 * Only not moved into the core for the hardware ring buffer cases
112 * that are more sophisticated.
114 static int max1363_ring_postenable(struct iio_dev *indio_dev)
116 if (indio_dev->trig == NULL)
118 return iio_trigger_attach_poll_func(indio_dev->trig,
119 indio_dev->pollfunc);
123 * max1363_ring_predisable() runs just prior to ring buffer being disabled
125 * Typical predisable function which ensures that no trigger events can
126 * occur before we disable the ring buffer (and hence would have no idea
127 * what to do with them)
129 static int max1363_ring_predisable(struct iio_dev *indio_dev)
132 return iio_trigger_dettach_poll_func(indio_dev->trig,
133 indio_dev->pollfunc);
139 * max1363_poll_func_th() th of trigger launched polling to ring buffer
141 * As sampling only occurs on i2c comms occuring, leave timestamping until
142 * then. Some triggers will generate their own time stamp. Currently
143 * there is no way of notifying them when no one cares.
145 static void max1363_poll_func_th(struct iio_dev *indio_dev)
147 struct max1363_state *st = indio_dev->dev_data;
149 schedule_work(&st->poll_work);
154 * max1363_poll_bh_to_ring() bh of trigger launched polling to ring buffer
155 * @work_s: the work struct through which this was scheduled
157 * Currently there is no option in this driver to disable the saving of
158 * timestamps within the ring.
159 * I think the one copy of this at a time was to avoid problems if the
160 * trigger was set far too high and the reads then locked up the computer.
162 static void max1363_poll_bh_to_ring(struct work_struct *work_s)
164 struct max1363_state *st = container_of(work_s, struct max1363_state,
166 struct iio_dev *indio_dev = st->indio_dev;
167 struct iio_sw_ring_buffer *ring = iio_to_sw_ring(indio_dev->ring);
172 unsigned long numvals = hweight_long(st->current_mode->modemask);
174 /* Ensure the timestamp is 8 byte aligned */
175 if (st->chip_info->bits != 8)
176 d_size = numvals*2 + sizeof(s64);
178 d_size = numvals + sizeof(s64);
179 if (d_size % sizeof(s64))
180 d_size += sizeof(s64) - (d_size % sizeof(s64));
182 /* Ensure only one copy of this function running at a time */
183 if (atomic_inc_return(&st->protect_ring) > 1)
186 /* Monitor mode prevents reading. Whilst not currently implemented
187 * might as well have this test in here in the meantime as it does
193 rxbuf = kmalloc(d_size, GFP_KERNEL);
196 if (st->chip_info->bits != 8)
197 b_sent = i2c_master_recv(st->client, rxbuf, numvals*2);
199 b_sent = i2c_master_recv(st->client, rxbuf, numvals);
203 time_ns = iio_get_time_ns();
205 memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
207 indio_dev->ring->access.store_to(&ring->buf, rxbuf, time_ns);
210 atomic_dec(&st->protect_ring);
214 int max1363_register_ring_funcs_and_init(struct iio_dev *indio_dev)
216 struct max1363_state *st = indio_dev->dev_data;
219 indio_dev->ring = iio_sw_rb_allocate(indio_dev);
220 if (!indio_dev->ring) {
224 /* Effectively select the ring buffer implementation */
225 iio_ring_sw_register_funcs(&st->indio_dev->ring->access);
226 indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
227 if (indio_dev->pollfunc == NULL) {
229 goto error_deallocate_sw_rb;
231 /* Configure the polling function called on trigger interrupts */
232 indio_dev->pollfunc->poll_func_main = &max1363_poll_func_th;
233 indio_dev->pollfunc->private_data = indio_dev;
235 /* Ring buffer functions - here trigger setup related */
236 indio_dev->ring->postenable = &max1363_ring_postenable;
237 indio_dev->ring->preenable = &max1363_ring_preenable;
238 indio_dev->ring->predisable = &max1363_ring_predisable;
239 INIT_WORK(&st->poll_work, &max1363_poll_bh_to_ring);
241 /* Flag that polled ring buffering is possible */
242 indio_dev->modes |= INDIO_RING_TRIGGERED;
244 error_deallocate_sw_rb:
245 iio_sw_rb_free(indio_dev->ring);
250 void max1363_ring_cleanup(struct iio_dev *indio_dev)
252 /* ensure that the trigger has been detached */
253 if (indio_dev->trig) {
254 iio_put_trigger(indio_dev->trig);
255 iio_trigger_dettach_poll_func(indio_dev->trig,
256 indio_dev->pollfunc);
258 kfree(indio_dev->pollfunc);
259 iio_sw_rb_free(indio_dev->ring);
262 void max1363_uninitialize_ring(struct iio_ring_buffer *ring)
264 iio_ring_buffer_unregister(ring);
267 int max1363_initialize_ring(struct iio_ring_buffer *ring)
269 return iio_ring_buffer_register(ring, 0);