1 /*
2 * sca3000_core.c -- support VTI sca3000 series accelerometers via SPI
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 as published by
6 * the Free Software Foundation.
7 *
8 * Copyright (c) 2009 Jonathan Cameron <jic23@kernel.org>
9 *
10 * See industrialio/accels/sca3000.h for comments.
11 */
12
13 #include <linux/interrupt.h>
14 #include <linux/fs.h>
15 #include <linux/device.h>
16 #include <linux/slab.h>
17 #include <linux/kernel.h>
18 #include <linux/spi/spi.h>
19 #include <linux/sysfs.h>
20 #include <linux/module.h>
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/events.h>
24 #include <linux/iio/buffer.h>
25
26 #include "sca3000.h"
27
28 enum sca3000_variant {
29 d01,
30 e02,
31 e04,
32 e05,
33 };
34
35 /*
36 * Note where option modes are not defined, the chip simply does not
37 * support any.
38 * Other chips in the sca3000 series use i2c and are not included here.
39 *
40 * Some of these devices are only listed in the family data sheet and
41 * do not actually appear to be available.
42 */
43 static const struct sca3000_chip_info sca3000_spi_chip_info_tbl[] = {
44 [d01] = {
45 .scale = 7357,
46 .temp_output = true,
47 .measurement_mode_freq = 250,
48 .option_mode_1 = SCA3000_OP_MODE_BYPASS,
49 .option_mode_1_freq = 250,
50 .mot_det_mult_xz = {50, 100, 200, 350, 650, 1300},
51 .mot_det_mult_y = {50, 100, 150, 250, 450, 850, 1750},
52 },
53 [e02] = {
54 .scale = 9810,
55 .measurement_mode_freq = 125,
56 .option_mode_1 = SCA3000_OP_MODE_NARROW,
57 .option_mode_1_freq = 63,
58 .mot_det_mult_xz = {100, 150, 300, 550, 1050, 2050},
59 .mot_det_mult_y = {50, 100, 200, 350, 700, 1350, 2700},
60 },
61 [e04] = {
62 .scale = 19620,
63 .measurement_mode_freq = 100,
64 .option_mode_1 = SCA3000_OP_MODE_NARROW,
65 .option_mode_1_freq = 50,
66 .option_mode_2 = SCA3000_OP_MODE_WIDE,
67 .option_mode_2_freq = 400,
68 .mot_det_mult_xz = {200, 300, 600, 1100, 2100, 4100},
69 .mot_det_mult_y = {100, 200, 400, 7000, 1400, 2700, 54000},
70 },
71 [e05] = {
72 .scale = 61313,
73 .measurement_mode_freq = 200,
74 .option_mode_1 = SCA3000_OP_MODE_NARROW,
75 .option_mode_1_freq = 50,
76 .option_mode_2 = SCA3000_OP_MODE_WIDE,
77 .option_mode_2_freq = 400,
78 .mot_det_mult_xz = {600, 900, 1700, 3200, 6100, 11900},
79 .mot_det_mult_y = {300, 600, 1200, 2000, 4100, 7800, 15600},
80 },
81 };
82
sca3000_write_reg(struct sca3000_state * st,u8 address,u8 val)83 int sca3000_write_reg(struct sca3000_state *st, u8 address, u8 val)
84 {
85 st->tx[0] = SCA3000_WRITE_REG(address);
86 st->tx[1] = val;
87 return spi_write(st->us, st->tx, 2);
88 }
89
sca3000_read_data_short(struct sca3000_state * st,uint8_t reg_address_high,int len)90 int sca3000_read_data_short(struct sca3000_state *st,
91 uint8_t reg_address_high,
92 int len)
93 {
94 struct spi_transfer xfer[2] = {
95 {
96 .len = 1,
97 .tx_buf = st->tx,
98 }, {
99 .len = len,
100 .rx_buf = st->rx,
101 }
102 };
103 st->tx[0] = SCA3000_READ_REG(reg_address_high);
104
105 return spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
106 }
107
108 /**
109 * sca3000_reg_lock_on() test if the ctrl register lock is on
110 *
111 * Lock must be held.
112 **/
sca3000_reg_lock_on(struct sca3000_state * st)113 static int sca3000_reg_lock_on(struct sca3000_state *st)
114 {
115 int ret;
116
117 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_STATUS, 1);
118 if (ret < 0)
119 return ret;
120
121 return !(st->rx[0] & SCA3000_LOCKED);
122 }
123
124 /**
125 * __sca3000_unlock_reg_lock() unlock the control registers
126 *
127 * Note the device does not appear to support doing this in a single transfer.
128 * This should only ever be used as part of ctrl reg read.
129 * Lock must be held before calling this
130 **/
__sca3000_unlock_reg_lock(struct sca3000_state * st)131 static int __sca3000_unlock_reg_lock(struct sca3000_state *st)
132 {
133 struct spi_transfer xfer[3] = {
134 {
135 .len = 2,
136 .cs_change = 1,
137 .tx_buf = st->tx,
138 }, {
139 .len = 2,
140 .cs_change = 1,
141 .tx_buf = st->tx + 2,
142 }, {
143 .len = 2,
144 .tx_buf = st->tx + 4,
145 },
146 };
147 st->tx[0] = SCA3000_WRITE_REG(SCA3000_REG_ADDR_UNLOCK);
148 st->tx[1] = 0x00;
149 st->tx[2] = SCA3000_WRITE_REG(SCA3000_REG_ADDR_UNLOCK);
150 st->tx[3] = 0x50;
151 st->tx[4] = SCA3000_WRITE_REG(SCA3000_REG_ADDR_UNLOCK);
152 st->tx[5] = 0xA0;
153
154 return spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
155 }
156
157 /**
158 * sca3000_write_ctrl_reg() write to a lock protect ctrl register
159 * @sel: selects which registers we wish to write to
160 * @val: the value to be written
161 *
162 * Certain control registers are protected against overwriting by the lock
163 * register and use a shared write address. This function allows writing of
164 * these registers.
165 * Lock must be held.
166 **/
sca3000_write_ctrl_reg(struct sca3000_state * st,uint8_t sel,uint8_t val)167 static int sca3000_write_ctrl_reg(struct sca3000_state *st,
168 uint8_t sel,
169 uint8_t val)
170 {
171
172 int ret;
173
174 ret = sca3000_reg_lock_on(st);
175 if (ret < 0)
176 goto error_ret;
177 if (ret) {
178 ret = __sca3000_unlock_reg_lock(st);
179 if (ret)
180 goto error_ret;
181 }
182
183 /* Set the control select register */
184 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_SEL, sel);
185 if (ret)
186 goto error_ret;
187
188 /* Write the actual value into the register */
189 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_DATA, val);
190
191 error_ret:
192 return ret;
193 }
194
195 /**
196 * sca3000_read_ctrl_reg() read from lock protected control register.
197 *
198 * Lock must be held.
199 **/
sca3000_read_ctrl_reg(struct sca3000_state * st,u8 ctrl_reg)200 static int sca3000_read_ctrl_reg(struct sca3000_state *st,
201 u8 ctrl_reg)
202 {
203 int ret;
204
205 ret = sca3000_reg_lock_on(st);
206 if (ret < 0)
207 goto error_ret;
208 if (ret) {
209 ret = __sca3000_unlock_reg_lock(st);
210 if (ret)
211 goto error_ret;
212 }
213 /* Set the control select register */
214 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_SEL, ctrl_reg);
215 if (ret)
216 goto error_ret;
217 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_CTRL_DATA, 1);
218 if (ret)
219 goto error_ret;
220 else
221 return st->rx[0];
222 error_ret:
223 return ret;
224 }
225
226 /**
227 * sca3000_show_rev() - sysfs interface to read the chip revision number
228 **/
sca3000_show_rev(struct device * dev,struct device_attribute * attr,char * buf)229 static ssize_t sca3000_show_rev(struct device *dev,
230 struct device_attribute *attr,
231 char *buf)
232 {
233 int len = 0, ret;
234 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
235 struct sca3000_state *st = iio_priv(indio_dev);
236
237 mutex_lock(&st->lock);
238 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_REVID, 1);
239 if (ret < 0)
240 goto error_ret;
241 len += sprintf(buf + len,
242 "major=%d, minor=%d\n",
243 st->rx[0] & SCA3000_REVID_MAJOR_MASK,
244 st->rx[0] & SCA3000_REVID_MINOR_MASK);
245 error_ret:
246 mutex_unlock(&st->lock);
247
248 return ret ? ret : len;
249 }
250
251 /**
252 * sca3000_show_available_measurement_modes() display available modes
253 *
254 * This is all read from chip specific data in the driver. Not all
255 * of the sca3000 series support modes other than normal.
256 **/
257 static ssize_t
sca3000_show_available_measurement_modes(struct device * dev,struct device_attribute * attr,char * buf)258 sca3000_show_available_measurement_modes(struct device *dev,
259 struct device_attribute *attr,
260 char *buf)
261 {
262 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
263 struct sca3000_state *st = iio_priv(indio_dev);
264 int len = 0;
265
266 len += sprintf(buf + len, "0 - normal mode");
267 switch (st->info->option_mode_1) {
268 case SCA3000_OP_MODE_NARROW:
269 len += sprintf(buf + len, ", 1 - narrow mode");
270 break;
271 case SCA3000_OP_MODE_BYPASS:
272 len += sprintf(buf + len, ", 1 - bypass mode");
273 break;
274 }
275 switch (st->info->option_mode_2) {
276 case SCA3000_OP_MODE_WIDE:
277 len += sprintf(buf + len, ", 2 - wide mode");
278 break;
279 }
280 /* always supported */
281 len += sprintf(buf + len, " 3 - motion detection\n");
282
283 return len;
284 }
285
286 /**
287 * sca3000_show_measurement_mode() sysfs read of current mode
288 **/
289 static ssize_t
sca3000_show_measurement_mode(struct device * dev,struct device_attribute * attr,char * buf)290 sca3000_show_measurement_mode(struct device *dev,
291 struct device_attribute *attr,
292 char *buf)
293 {
294 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
295 struct sca3000_state *st = iio_priv(indio_dev);
296 int len = 0, ret;
297
298 mutex_lock(&st->lock);
299 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
300 if (ret)
301 goto error_ret;
302 /* mask bottom 2 bits - only ones that are relevant */
303 st->rx[0] &= 0x03;
304 switch (st->rx[0]) {
305 case SCA3000_MEAS_MODE_NORMAL:
306 len += sprintf(buf + len, "0 - normal mode\n");
307 break;
308 case SCA3000_MEAS_MODE_MOT_DET:
309 len += sprintf(buf + len, "3 - motion detection\n");
310 break;
311 case SCA3000_MEAS_MODE_OP_1:
312 switch (st->info->option_mode_1) {
313 case SCA3000_OP_MODE_NARROW:
314 len += sprintf(buf + len, "1 - narrow mode\n");
315 break;
316 case SCA3000_OP_MODE_BYPASS:
317 len += sprintf(buf + len, "1 - bypass mode\n");
318 break;
319 }
320 break;
321 case SCA3000_MEAS_MODE_OP_2:
322 switch (st->info->option_mode_2) {
323 case SCA3000_OP_MODE_WIDE:
324 len += sprintf(buf + len, "2 - wide mode\n");
325 break;
326 }
327 break;
328 }
329
330 error_ret:
331 mutex_unlock(&st->lock);
332
333 return ret ? ret : len;
334 }
335
336 /**
337 * sca3000_store_measurement_mode() set the current mode
338 **/
339 static ssize_t
sca3000_store_measurement_mode(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)340 sca3000_store_measurement_mode(struct device *dev,
341 struct device_attribute *attr,
342 const char *buf,
343 size_t len)
344 {
345 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
346 struct sca3000_state *st = iio_priv(indio_dev);
347 int ret;
348 u8 mask = 0x03;
349 u8 val;
350
351 mutex_lock(&st->lock);
352 ret = kstrtou8(buf, 10, &val);
353 if (ret)
354 goto error_ret;
355 if (val > 3) {
356 ret = -EINVAL;
357 goto error_ret;
358 }
359 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
360 if (ret)
361 goto error_ret;
362 st->rx[0] &= ~mask;
363 st->rx[0] |= (val & mask);
364 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE, st->rx[0]);
365 if (ret)
366 goto error_ret;
367 mutex_unlock(&st->lock);
368
369 return len;
370
371 error_ret:
372 mutex_unlock(&st->lock);
373
374 return ret;
375 }
376
377
378 /*
379 * Not even vaguely standard attributes so defined here rather than
380 * in the relevant IIO core headers
381 */
382 static IIO_DEVICE_ATTR(measurement_mode_available, S_IRUGO,
383 sca3000_show_available_measurement_modes,
384 NULL, 0);
385
386 static IIO_DEVICE_ATTR(measurement_mode, S_IRUGO | S_IWUSR,
387 sca3000_show_measurement_mode,
388 sca3000_store_measurement_mode,
389 0);
390
391 /* More standard attributes */
392
393 static IIO_DEVICE_ATTR(revision, S_IRUGO, sca3000_show_rev, NULL, 0);
394
395 static const struct iio_event_spec sca3000_event = {
396 .type = IIO_EV_TYPE_MAG,
397 .dir = IIO_EV_DIR_RISING,
398 .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
399 };
400
401 #define SCA3000_CHAN(index, mod) \
402 { \
403 .type = IIO_ACCEL, \
404 .modified = 1, \
405 .channel2 = mod, \
406 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
407 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
408 .address = index, \
409 .scan_index = index, \
410 .scan_type = { \
411 .sign = 's', \
412 .realbits = 11, \
413 .storagebits = 16, \
414 .shift = 5, \
415 }, \
416 .event_spec = &sca3000_event, \
417 .num_event_specs = 1, \
418 }
419
420 static const struct iio_chan_spec sca3000_channels[] = {
421 SCA3000_CHAN(0, IIO_MOD_X),
422 SCA3000_CHAN(1, IIO_MOD_Y),
423 SCA3000_CHAN(2, IIO_MOD_Z),
424 };
425
426 static const struct iio_chan_spec sca3000_channels_with_temp[] = {
427 SCA3000_CHAN(0, IIO_MOD_X),
428 SCA3000_CHAN(1, IIO_MOD_Y),
429 SCA3000_CHAN(2, IIO_MOD_Z),
430 {
431 .type = IIO_TEMP,
432 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
433 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
434 BIT(IIO_CHAN_INFO_OFFSET),
435 /* No buffer support */
436 .scan_index = -1,
437 },
438 };
439
440 static u8 sca3000_addresses[3][3] = {
441 [0] = {SCA3000_REG_ADDR_X_MSB, SCA3000_REG_CTRL_SEL_MD_X_TH,
442 SCA3000_MD_CTRL_OR_X},
443 [1] = {SCA3000_REG_ADDR_Y_MSB, SCA3000_REG_CTRL_SEL_MD_Y_TH,
444 SCA3000_MD_CTRL_OR_Y},
445 [2] = {SCA3000_REG_ADDR_Z_MSB, SCA3000_REG_CTRL_SEL_MD_Z_TH,
446 SCA3000_MD_CTRL_OR_Z},
447 };
448
sca3000_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)449 static int sca3000_read_raw(struct iio_dev *indio_dev,
450 struct iio_chan_spec const *chan,
451 int *val,
452 int *val2,
453 long mask)
454 {
455 struct sca3000_state *st = iio_priv(indio_dev);
456 int ret;
457 u8 address;
458
459 switch (mask) {
460 case IIO_CHAN_INFO_RAW:
461 mutex_lock(&st->lock);
462 if (chan->type == IIO_ACCEL) {
463 if (st->mo_det_use_count) {
464 mutex_unlock(&st->lock);
465 return -EBUSY;
466 }
467 address = sca3000_addresses[chan->address][0];
468 ret = sca3000_read_data_short(st, address, 2);
469 if (ret < 0) {
470 mutex_unlock(&st->lock);
471 return ret;
472 }
473 *val = (be16_to_cpup((__be16 *)st->rx) >> 3) & 0x1FFF;
474 *val = ((*val) << (sizeof(*val)*8 - 13)) >>
475 (sizeof(*val)*8 - 13);
476 } else {
477 /* get the temperature when available */
478 ret = sca3000_read_data_short(st,
479 SCA3000_REG_ADDR_TEMP_MSB, 2);
480 if (ret < 0) {
481 mutex_unlock(&st->lock);
482 return ret;
483 }
484 *val = ((st->rx[0] & 0x3F) << 3) |
485 ((st->rx[1] & 0xE0) >> 5);
486 }
487 mutex_unlock(&st->lock);
488 return IIO_VAL_INT;
489 case IIO_CHAN_INFO_SCALE:
490 *val = 0;
491 if (chan->type == IIO_ACCEL)
492 *val2 = st->info->scale;
493 else /* temperature */
494 *val2 = 555556;
495 return IIO_VAL_INT_PLUS_MICRO;
496 case IIO_CHAN_INFO_OFFSET:
497 *val = -214;
498 *val2 = 600000;
499 return IIO_VAL_INT_PLUS_MICRO;
500 default:
501 return -EINVAL;
502 }
503 }
504
505 /**
506 * sca3000_read_av_freq() sysfs function to get available frequencies
507 *
508 * The later modes are only relevant to the ring buffer - and depend on current
509 * mode. Note that data sheet gives rather wide tolerances for these so integer
510 * division will give good enough answer and not all chips have them specified
511 * at all.
512 **/
sca3000_read_av_freq(struct device * dev,struct device_attribute * attr,char * buf)513 static ssize_t sca3000_read_av_freq(struct device *dev,
514 struct device_attribute *attr,
515 char *buf)
516 {
517 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
518 struct sca3000_state *st = iio_priv(indio_dev);
519 int len = 0, ret, val;
520
521 mutex_lock(&st->lock);
522 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
523 val = st->rx[0];
524 mutex_unlock(&st->lock);
525 if (ret)
526 goto error_ret;
527
528 switch (val & 0x03) {
529 case SCA3000_MEAS_MODE_NORMAL:
530 len += sprintf(buf + len, "%d %d %d\n",
531 st->info->measurement_mode_freq,
532 st->info->measurement_mode_freq/2,
533 st->info->measurement_mode_freq/4);
534 break;
535 case SCA3000_MEAS_MODE_OP_1:
536 len += sprintf(buf + len, "%d %d %d\n",
537 st->info->option_mode_1_freq,
538 st->info->option_mode_1_freq/2,
539 st->info->option_mode_1_freq/4);
540 break;
541 case SCA3000_MEAS_MODE_OP_2:
542 len += sprintf(buf + len, "%d %d %d\n",
543 st->info->option_mode_2_freq,
544 st->info->option_mode_2_freq/2,
545 st->info->option_mode_2_freq/4);
546 break;
547 }
548 return len;
549 error_ret:
550 return ret;
551 }
552 /**
553 * __sca3000_get_base_freq() obtain mode specific base frequency
554 *
555 * lock must be held
556 **/
__sca3000_get_base_freq(struct sca3000_state * st,const struct sca3000_chip_info * info,int * base_freq)557 static inline int __sca3000_get_base_freq(struct sca3000_state *st,
558 const struct sca3000_chip_info *info,
559 int *base_freq)
560 {
561 int ret;
562
563 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
564 if (ret)
565 goto error_ret;
566 switch (0x03 & st->rx[0]) {
567 case SCA3000_MEAS_MODE_NORMAL:
568 *base_freq = info->measurement_mode_freq;
569 break;
570 case SCA3000_MEAS_MODE_OP_1:
571 *base_freq = info->option_mode_1_freq;
572 break;
573 case SCA3000_MEAS_MODE_OP_2:
574 *base_freq = info->option_mode_2_freq;
575 break;
576 }
577 error_ret:
578 return ret;
579 }
580
581 /**
582 * sca3000_read_frequency() sysfs interface to get the current frequency
583 **/
sca3000_read_frequency(struct device * dev,struct device_attribute * attr,char * buf)584 static ssize_t sca3000_read_frequency(struct device *dev,
585 struct device_attribute *attr,
586 char *buf)
587 {
588 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
589 struct sca3000_state *st = iio_priv(indio_dev);
590 int ret, len = 0, base_freq = 0, val;
591
592 mutex_lock(&st->lock);
593 ret = __sca3000_get_base_freq(st, st->info, &base_freq);
594 if (ret)
595 goto error_ret_mut;
596 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);
597 mutex_unlock(&st->lock);
598 if (ret)
599 goto error_ret;
600 val = ret;
601 if (base_freq > 0)
602 switch (val & 0x03) {
603 case 0x00:
604 case 0x03:
605 len = sprintf(buf, "%d\n", base_freq);
606 break;
607 case 0x01:
608 len = sprintf(buf, "%d\n", base_freq/2);
609 break;
610 case 0x02:
611 len = sprintf(buf, "%d\n", base_freq/4);
612 break;
613 }
614
615 return len;
616 error_ret_mut:
617 mutex_unlock(&st->lock);
618 error_ret:
619 return ret;
620 }
621
622 /**
623 * sca3000_set_frequency() sysfs interface to set the current frequency
624 **/
sca3000_set_frequency(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)625 static ssize_t sca3000_set_frequency(struct device *dev,
626 struct device_attribute *attr,
627 const char *buf,
628 size_t len)
629 {
630 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
631 struct sca3000_state *st = iio_priv(indio_dev);
632 int ret, base_freq = 0;
633 int ctrlval;
634 int val;
635
636 ret = kstrtoint(buf, 10, &val);
637 if (ret)
638 return ret;
639
640 mutex_lock(&st->lock);
641 /* What mode are we in? */
642 ret = __sca3000_get_base_freq(st, st->info, &base_freq);
643 if (ret)
644 goto error_free_lock;
645
646 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);
647 if (ret < 0)
648 goto error_free_lock;
649 ctrlval = ret;
650 /* clear the bits */
651 ctrlval &= ~0x03;
652
653 if (val == base_freq/2) {
654 ctrlval |= SCA3000_OUT_CTRL_BUF_DIV_2;
655 } else if (val == base_freq/4) {
656 ctrlval |= SCA3000_OUT_CTRL_BUF_DIV_4;
657 } else if (val != base_freq) {
658 ret = -EINVAL;
659 goto error_free_lock;
660 }
661 ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL,
662 ctrlval);
663 error_free_lock:
664 mutex_unlock(&st->lock);
665
666 return ret ? ret : len;
667 }
668
669 /*
670 * Should only really be registered if ring buffer support is compiled in.
671 * Does no harm however and doing it right would add a fair bit of complexity
672 */
673 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(sca3000_read_av_freq);
674
675 static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
676 sca3000_read_frequency,
677 sca3000_set_frequency);
678
679 /**
680 * sca3000_read_thresh() - query of a threshold
681 **/
sca3000_read_thresh(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir,enum iio_event_info info,int * val,int * val2)682 static int sca3000_read_thresh(struct iio_dev *indio_dev,
683 const struct iio_chan_spec *chan,
684 enum iio_event_type type,
685 enum iio_event_direction dir,
686 enum iio_event_info info,
687 int *val, int *val2)
688 {
689 int ret, i;
690 struct sca3000_state *st = iio_priv(indio_dev);
691 int num = chan->channel2;
692
693 mutex_lock(&st->lock);
694 ret = sca3000_read_ctrl_reg(st, sca3000_addresses[num][1]);
695 mutex_unlock(&st->lock);
696 if (ret < 0)
697 return ret;
698 *val = 0;
699 if (num == 1)
700 for_each_set_bit(i, (unsigned long *)&ret,
701 ARRAY_SIZE(st->info->mot_det_mult_y))
702 *val += st->info->mot_det_mult_y[i];
703 else
704 for_each_set_bit(i, (unsigned long *)&ret,
705 ARRAY_SIZE(st->info->mot_det_mult_xz))
706 *val += st->info->mot_det_mult_xz[i];
707
708 return IIO_VAL_INT;
709 }
710
711 /**
712 * sca3000_write_thresh() control of threshold
713 **/
sca3000_write_thresh(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir,enum iio_event_info info,int val,int val2)714 static int sca3000_write_thresh(struct iio_dev *indio_dev,
715 const struct iio_chan_spec *chan,
716 enum iio_event_type type,
717 enum iio_event_direction dir,
718 enum iio_event_info info,
719 int val, int val2)
720 {
721 struct sca3000_state *st = iio_priv(indio_dev);
722 int num = chan->channel2;
723 int ret;
724 int i;
725 u8 nonlinear = 0;
726
727 if (num == 1) {
728 i = ARRAY_SIZE(st->info->mot_det_mult_y);
729 while (i > 0)
730 if (val >= st->info->mot_det_mult_y[--i]) {
731 nonlinear |= (1 << i);
732 val -= st->info->mot_det_mult_y[i];
733 }
734 } else {
735 i = ARRAY_SIZE(st->info->mot_det_mult_xz);
736 while (i > 0)
737 if (val >= st->info->mot_det_mult_xz[--i]) {
738 nonlinear |= (1 << i);
739 val -= st->info->mot_det_mult_xz[i];
740 }
741 }
742
743 mutex_lock(&st->lock);
744 ret = sca3000_write_ctrl_reg(st, sca3000_addresses[num][1], nonlinear);
745 mutex_unlock(&st->lock);
746
747 return ret;
748 }
749
750 static struct attribute *sca3000_attributes[] = {
751 &iio_dev_attr_revision.dev_attr.attr,
752 &iio_dev_attr_measurement_mode_available.dev_attr.attr,
753 &iio_dev_attr_measurement_mode.dev_attr.attr,
754 &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
755 &iio_dev_attr_sampling_frequency.dev_attr.attr,
756 NULL,
757 };
758
759 static const struct attribute_group sca3000_attribute_group = {
760 .attrs = sca3000_attributes,
761 };
762
763 /**
764 * sca3000_event_handler() - handling ring and non ring events
765 *
766 * Ring related interrupt handler. Depending on event, push to
767 * the ring buffer event chrdev or the event one.
768 *
769 * This function is complicated by the fact that the devices can signify ring
770 * and non ring events via the same interrupt line and they can only
771 * be distinguished via a read of the relevant status register.
772 **/
sca3000_event_handler(int irq,void * private)773 static irqreturn_t sca3000_event_handler(int irq, void *private)
774 {
775 struct iio_dev *indio_dev = private;
776 struct sca3000_state *st = iio_priv(indio_dev);
777 int ret, val;
778 s64 last_timestamp = iio_get_time_ns();
779
780 /*
781 * Could lead if badly timed to an extra read of status reg,
782 * but ensures no interrupt is missed.
783 */
784 mutex_lock(&st->lock);
785 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_STATUS, 1);
786 val = st->rx[0];
787 mutex_unlock(&st->lock);
788 if (ret)
789 goto done;
790
791 sca3000_ring_int_process(val, indio_dev->buffer);
792
793 if (val & SCA3000_INT_STATUS_FREE_FALL)
794 iio_push_event(indio_dev,
795 IIO_MOD_EVENT_CODE(IIO_ACCEL,
796 0,
797 IIO_MOD_X_AND_Y_AND_Z,
798 IIO_EV_TYPE_MAG,
799 IIO_EV_DIR_FALLING),
800 last_timestamp);
801
802 if (val & SCA3000_INT_STATUS_Y_TRIGGER)
803 iio_push_event(indio_dev,
804 IIO_MOD_EVENT_CODE(IIO_ACCEL,
805 0,
806 IIO_MOD_Y,
807 IIO_EV_TYPE_MAG,
808 IIO_EV_DIR_RISING),
809 last_timestamp);
810
811 if (val & SCA3000_INT_STATUS_X_TRIGGER)
812 iio_push_event(indio_dev,
813 IIO_MOD_EVENT_CODE(IIO_ACCEL,
814 0,
815 IIO_MOD_X,
816 IIO_EV_TYPE_MAG,
817 IIO_EV_DIR_RISING),
818 last_timestamp);
819
820 if (val & SCA3000_INT_STATUS_Z_TRIGGER)
821 iio_push_event(indio_dev,
822 IIO_MOD_EVENT_CODE(IIO_ACCEL,
823 0,
824 IIO_MOD_Z,
825 IIO_EV_TYPE_MAG,
826 IIO_EV_DIR_RISING),
827 last_timestamp);
828
829 done:
830 return IRQ_HANDLED;
831 }
832
833 /**
834 * sca3000_read_event_config() what events are enabled
835 **/
sca3000_read_event_config(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir)836 static int sca3000_read_event_config(struct iio_dev *indio_dev,
837 const struct iio_chan_spec *chan,
838 enum iio_event_type type,
839 enum iio_event_direction dir)
840 {
841 struct sca3000_state *st = iio_priv(indio_dev);
842 int ret;
843 u8 protect_mask = 0x03;
844 int num = chan->channel2;
845
846 /* read current value of mode register */
847 mutex_lock(&st->lock);
848 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
849 if (ret)
850 goto error_ret;
851
852 if ((st->rx[0] & protect_mask) != SCA3000_MEAS_MODE_MOT_DET)
853 ret = 0;
854 else {
855 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL);
856 if (ret < 0)
857 goto error_ret;
858 /* only supporting logical or's for now */
859 ret = !!(ret & sca3000_addresses[num][2]);
860 }
861 error_ret:
862 mutex_unlock(&st->lock);
863
864 return ret;
865 }
866 /**
867 * sca3000_query_free_fall_mode() is free fall mode enabled
868 **/
sca3000_query_free_fall_mode(struct device * dev,struct device_attribute * attr,char * buf)869 static ssize_t sca3000_query_free_fall_mode(struct device *dev,
870 struct device_attribute *attr,
871 char *buf)
872 {
873 int ret;
874 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
875 struct sca3000_state *st = iio_priv(indio_dev);
876 int val;
877
878 mutex_lock(&st->lock);
879 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
880 val = st->rx[0];
881 mutex_unlock(&st->lock);
882 if (ret < 0)
883 return ret;
884 return sprintf(buf, "%d\n", !!(val & SCA3000_FREE_FALL_DETECT));
885 }
886
887 /**
888 * sca3000_set_free_fall_mode() simple on off control for free fall int
889 *
890 * In these chips the free fall detector should send an interrupt if
891 * the device falls more than 25cm. This has not been tested due
892 * to fragile wiring.
893 **/
sca3000_set_free_fall_mode(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)894 static ssize_t sca3000_set_free_fall_mode(struct device *dev,
895 struct device_attribute *attr,
896 const char *buf,
897 size_t len)
898 {
899 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
900 struct sca3000_state *st = iio_priv(indio_dev);
901 u8 val;
902 int ret;
903 u8 protect_mask = SCA3000_FREE_FALL_DETECT;
904
905 mutex_lock(&st->lock);
906 ret = kstrtou8(buf, 10, &val);
907 if (ret)
908 goto error_ret;
909
910 /* read current value of mode register */
911 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
912 if (ret)
913 goto error_ret;
914
915 /* if off and should be on */
916 if (val && !(st->rx[0] & protect_mask))
917 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
918 (st->rx[0] | SCA3000_FREE_FALL_DETECT));
919 /* if on and should be off */
920 else if (!val && (st->rx[0] & protect_mask))
921 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
922 (st->rx[0] & ~protect_mask));
923 error_ret:
924 mutex_unlock(&st->lock);
925
926 return ret ? ret : len;
927 }
928
929 /**
930 * sca3000_write_event_config() simple on off control for motion detector
931 *
932 * This is a per axis control, but enabling any will result in the
933 * motion detector unit being enabled.
934 * N.B. enabling motion detector stops normal data acquisition.
935 * There is a complexity in knowing which mode to return to when
936 * this mode is disabled. Currently normal mode is assumed.
937 **/
sca3000_write_event_config(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir,int state)938 static int sca3000_write_event_config(struct iio_dev *indio_dev,
939 const struct iio_chan_spec *chan,
940 enum iio_event_type type,
941 enum iio_event_direction dir,
942 int state)
943 {
944 struct sca3000_state *st = iio_priv(indio_dev);
945 int ret, ctrlval;
946 u8 protect_mask = 0x03;
947 int num = chan->channel2;
948
949 mutex_lock(&st->lock);
950 /*
951 * First read the motion detector config to find out if
952 * this axis is on
953 */
954 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL);
955 if (ret < 0)
956 goto exit_point;
957 ctrlval = ret;
958 /* if off and should be on */
959 if (state && !(ctrlval & sca3000_addresses[num][2])) {
960 ret = sca3000_write_ctrl_reg(st,
961 SCA3000_REG_CTRL_SEL_MD_CTRL,
962 ctrlval |
963 sca3000_addresses[num][2]);
964 if (ret)
965 goto exit_point;
966 st->mo_det_use_count++;
967 } else if (!state && (ctrlval & sca3000_addresses[num][2])) {
968 ret = sca3000_write_ctrl_reg(st,
969 SCA3000_REG_CTRL_SEL_MD_CTRL,
970 ctrlval &
971 ~(sca3000_addresses[num][2]));
972 if (ret)
973 goto exit_point;
974 st->mo_det_use_count--;
975 }
976
977 /* read current value of mode register */
978 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
979 if (ret)
980 goto exit_point;
981 /* if off and should be on */
982 if ((st->mo_det_use_count)
983 && ((st->rx[0] & protect_mask) != SCA3000_MEAS_MODE_MOT_DET))
984 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
985 (st->rx[0] & ~protect_mask)
986 | SCA3000_MEAS_MODE_MOT_DET);
987 /* if on and should be off */
988 else if (!(st->mo_det_use_count)
989 && ((st->rx[0] & protect_mask) == SCA3000_MEAS_MODE_MOT_DET))
990 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
991 (st->rx[0] & ~protect_mask));
992 exit_point:
993 mutex_unlock(&st->lock);
994
995 return ret;
996 }
997
998 /* Free fall detector related event attribute */
999 static IIO_DEVICE_ATTR_NAMED(accel_xayaz_mag_falling_en,
1000 in_accel_x&y&z_mag_falling_en,
1001 S_IRUGO | S_IWUSR,
1002 sca3000_query_free_fall_mode,
1003 sca3000_set_free_fall_mode,
1004 0);
1005
1006 static IIO_CONST_ATTR_NAMED(accel_xayaz_mag_falling_period,
1007 in_accel_x&y&z_mag_falling_period,
1008 "0.226");
1009
1010 static struct attribute *sca3000_event_attributes[] = {
1011 &iio_dev_attr_accel_xayaz_mag_falling_en.dev_attr.attr,
1012 &iio_const_attr_accel_xayaz_mag_falling_period.dev_attr.attr,
1013 NULL,
1014 };
1015
1016 static struct attribute_group sca3000_event_attribute_group = {
1017 .attrs = sca3000_event_attributes,
1018 .name = "events",
1019 };
1020
1021 /**
1022 * sca3000_clean_setup() get the device into a predictable state
1023 *
1024 * Devices use flash memory to store many of the register values
1025 * and hence can come up in somewhat unpredictable states.
1026 * Hence reset everything on driver load.
1027 **/
sca3000_clean_setup(struct sca3000_state * st)1028 static int sca3000_clean_setup(struct sca3000_state *st)
1029 {
1030 int ret;
1031
1032 mutex_lock(&st->lock);
1033 /* Ensure all interrupts have been acknowledged */
1034 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_STATUS, 1);
1035 if (ret)
1036 goto error_ret;
1037
1038 /* Turn off all motion detection channels */
1039 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL);
1040 if (ret < 0)
1041 goto error_ret;
1042 ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL,
1043 ret & SCA3000_MD_CTRL_PROT_MASK);
1044 if (ret)
1045 goto error_ret;
1046
1047 /* Disable ring buffer */
1048 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);
1049 ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL,
1050 (ret & SCA3000_OUT_CTRL_PROT_MASK)
1051 | SCA3000_OUT_CTRL_BUF_X_EN
1052 | SCA3000_OUT_CTRL_BUF_Y_EN
1053 | SCA3000_OUT_CTRL_BUF_Z_EN
1054 | SCA3000_OUT_CTRL_BUF_DIV_4);
1055 if (ret)
1056 goto error_ret;
1057 /* Enable interrupts, relevant to mode and set up as active low */
1058 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_MASK, 1);
1059 if (ret)
1060 goto error_ret;
1061 ret = sca3000_write_reg(st,
1062 SCA3000_REG_ADDR_INT_MASK,
1063 (ret & SCA3000_INT_MASK_PROT_MASK)
1064 | SCA3000_INT_MASK_ACTIVE_LOW);
1065 if (ret)
1066 goto error_ret;
1067 /*
1068 * Select normal measurement mode, free fall off, ring off
1069 * Ring in 12 bit mode - it is fine to overwrite reserved bits 3,5
1070 * as that occurs in one of the example on the datasheet
1071 */
1072 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
1073 if (ret)
1074 goto error_ret;
1075 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
1076 (st->rx[0] & SCA3000_MODE_PROT_MASK));
1077 st->bpse = 11;
1078
1079 error_ret:
1080 mutex_unlock(&st->lock);
1081 return ret;
1082 }
1083
1084 static const struct iio_info sca3000_info = {
1085 .attrs = &sca3000_attribute_group,
1086 .read_raw = &sca3000_read_raw,
1087 .event_attrs = &sca3000_event_attribute_group,
1088 .read_event_value = &sca3000_read_thresh,
1089 .write_event_value = &sca3000_write_thresh,
1090 .read_event_config = &sca3000_read_event_config,
1091 .write_event_config = &sca3000_write_event_config,
1092 .driver_module = THIS_MODULE,
1093 };
1094
sca3000_probe(struct spi_device * spi)1095 static int sca3000_probe(struct spi_device *spi)
1096 {
1097 int ret;
1098 struct sca3000_state *st;
1099 struct iio_dev *indio_dev;
1100
1101 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
1102 if (!indio_dev)
1103 return -ENOMEM;
1104
1105 st = iio_priv(indio_dev);
1106 spi_set_drvdata(spi, indio_dev);
1107 st->us = spi;
1108 mutex_init(&st->lock);
1109 st->info = &sca3000_spi_chip_info_tbl[spi_get_device_id(spi)
1110 ->driver_data];
1111
1112 indio_dev->dev.parent = &spi->dev;
1113 indio_dev->name = spi_get_device_id(spi)->name;
1114 indio_dev->info = &sca3000_info;
1115 if (st->info->temp_output) {
1116 indio_dev->channels = sca3000_channels_with_temp;
1117 indio_dev->num_channels =
1118 ARRAY_SIZE(sca3000_channels_with_temp);
1119 } else {
1120 indio_dev->channels = sca3000_channels;
1121 indio_dev->num_channels = ARRAY_SIZE(sca3000_channels);
1122 }
1123 indio_dev->modes = INDIO_DIRECT_MODE;
1124
1125 sca3000_configure_ring(indio_dev);
1126 ret = iio_device_register(indio_dev);
1127 if (ret < 0)
1128 return ret;
1129
1130 if (spi->irq) {
1131 ret = request_threaded_irq(spi->irq,
1132 NULL,
1133 &sca3000_event_handler,
1134 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1135 "sca3000",
1136 indio_dev);
1137 if (ret)
1138 goto error_unregister_dev;
1139 }
1140 sca3000_register_ring_funcs(indio_dev);
1141 ret = sca3000_clean_setup(st);
1142 if (ret)
1143 goto error_free_irq;
1144 return 0;
1145
1146 error_free_irq:
1147 if (spi->irq)
1148 free_irq(spi->irq, indio_dev);
1149 error_unregister_dev:
1150 iio_device_unregister(indio_dev);
1151 return ret;
1152 }
1153
sca3000_stop_all_interrupts(struct sca3000_state * st)1154 static int sca3000_stop_all_interrupts(struct sca3000_state *st)
1155 {
1156 int ret;
1157
1158 mutex_lock(&st->lock);
1159 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_MASK, 1);
1160 if (ret)
1161 goto error_ret;
1162 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_INT_MASK,
1163 (st->rx[0] &
1164 ~(SCA3000_INT_MASK_RING_THREE_QUARTER |
1165 SCA3000_INT_MASK_RING_HALF |
1166 SCA3000_INT_MASK_ALL_INTS)));
1167 error_ret:
1168 mutex_unlock(&st->lock);
1169 return ret;
1170 }
1171
sca3000_remove(struct spi_device * spi)1172 static int sca3000_remove(struct spi_device *spi)
1173 {
1174 struct iio_dev *indio_dev = spi_get_drvdata(spi);
1175 struct sca3000_state *st = iio_priv(indio_dev);
1176
1177 /* Must ensure no interrupts can be generated after this! */
1178 sca3000_stop_all_interrupts(st);
1179 if (spi->irq)
1180 free_irq(spi->irq, indio_dev);
1181 iio_device_unregister(indio_dev);
1182 sca3000_unconfigure_ring(indio_dev);
1183
1184 return 0;
1185 }
1186
1187 static const struct spi_device_id sca3000_id[] = {
1188 {"sca3000_d01", d01},
1189 {"sca3000_e02", e02},
1190 {"sca3000_e04", e04},
1191 {"sca3000_e05", e05},
1192 {}
1193 };
1194 MODULE_DEVICE_TABLE(spi, sca3000_id);
1195
1196 static struct spi_driver sca3000_driver = {
1197 .driver = {
1198 .name = "sca3000",
1199 .owner = THIS_MODULE,
1200 },
1201 .probe = sca3000_probe,
1202 .remove = sca3000_remove,
1203 .id_table = sca3000_id,
1204 };
1205 module_spi_driver(sca3000_driver);
1206
1207 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1208 MODULE_DESCRIPTION("VTI SCA3000 Series Accelerometers SPI driver");
1209 MODULE_LICENSE("GPL v2");
1210