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,u8 reg_address_high,int len)90 int sca3000_read_data_short(struct sca3000_state *st,
91 u8 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,u8 sel,uint8_t val)167 static int sca3000_write_ctrl_reg(struct sca3000_state *st,
168 u8 sel,
169 uint8_t val)
170 {
171 int ret;
172
173 ret = sca3000_reg_lock_on(st);
174 if (ret < 0)
175 goto error_ret;
176 if (ret) {
177 ret = __sca3000_unlock_reg_lock(st);
178 if (ret)
179 goto error_ret;
180 }
181
182 /* Set the control select register */
183 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_SEL, sel);
184 if (ret)
185 goto error_ret;
186
187 /* Write the actual value into the register */
188 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_DATA, val);
189
190 error_ret:
191 return ret;
192 }
193
194 /**
195 * sca3000_read_ctrl_reg() read from lock protected control register.
196 *
197 * Lock must be held.
198 **/
sca3000_read_ctrl_reg(struct sca3000_state * st,u8 ctrl_reg)199 static int sca3000_read_ctrl_reg(struct sca3000_state *st,
200 u8 ctrl_reg)
201 {
202 int ret;
203
204 ret = sca3000_reg_lock_on(st);
205 if (ret < 0)
206 goto error_ret;
207 if (ret) {
208 ret = __sca3000_unlock_reg_lock(st);
209 if (ret)
210 goto error_ret;
211 }
212 /* Set the control select register */
213 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_SEL, ctrl_reg);
214 if (ret)
215 goto error_ret;
216 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_CTRL_DATA, 1);
217 if (ret)
218 goto error_ret;
219 else
220 return st->rx[0];
221 error_ret:
222 return ret;
223 }
224
225 /**
226 * sca3000_show_rev() - sysfs interface to read the chip revision number
227 **/
sca3000_show_rev(struct device * dev,struct device_attribute * attr,char * buf)228 static ssize_t sca3000_show_rev(struct device *dev,
229 struct device_attribute *attr,
230 char *buf)
231 {
232 int len = 0, ret;
233 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
234 struct sca3000_state *st = iio_priv(indio_dev);
235
236 mutex_lock(&st->lock);
237 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_REVID, 1);
238 if (ret < 0)
239 goto error_ret;
240 len += sprintf(buf + len,
241 "major=%d, minor=%d\n",
242 st->rx[0] & SCA3000_REVID_MAJOR_MASK,
243 st->rx[0] & SCA3000_REVID_MINOR_MASK);
244 error_ret:
245 mutex_unlock(&st->lock);
246
247 return ret ? ret : len;
248 }
249
250 /**
251 * sca3000_show_available_measurement_modes() display available modes
252 *
253 * This is all read from chip specific data in the driver. Not all
254 * of the sca3000 series support modes other than normal.
255 **/
256 static ssize_t
sca3000_show_available_measurement_modes(struct device * dev,struct device_attribute * attr,char * buf)257 sca3000_show_available_measurement_modes(struct device *dev,
258 struct device_attribute *attr,
259 char *buf)
260 {
261 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
262 struct sca3000_state *st = iio_priv(indio_dev);
263 int len = 0;
264
265 len += sprintf(buf + len, "0 - normal mode");
266 switch (st->info->option_mode_1) {
267 case SCA3000_OP_MODE_NARROW:
268 len += sprintf(buf + len, ", 1 - narrow mode");
269 break;
270 case SCA3000_OP_MODE_BYPASS:
271 len += sprintf(buf + len, ", 1 - bypass mode");
272 break;
273 }
274 switch (st->info->option_mode_2) {
275 case SCA3000_OP_MODE_WIDE:
276 len += sprintf(buf + len, ", 2 - wide mode");
277 break;
278 }
279 /* always supported */
280 len += sprintf(buf + len, " 3 - motion detection\n");
281
282 return len;
283 }
284
285 /**
286 * sca3000_show_measurement_mode() sysfs read of current mode
287 **/
288 static ssize_t
sca3000_show_measurement_mode(struct device * dev,struct device_attribute * attr,char * buf)289 sca3000_show_measurement_mode(struct device *dev,
290 struct device_attribute *attr,
291 char *buf)
292 {
293 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
294 struct sca3000_state *st = iio_priv(indio_dev);
295 int len = 0, ret;
296
297 mutex_lock(&st->lock);
298 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
299 if (ret)
300 goto error_ret;
301 /* mask bottom 2 bits - only ones that are relevant */
302 st->rx[0] &= 0x03;
303 switch (st->rx[0]) {
304 case SCA3000_MEAS_MODE_NORMAL:
305 len += sprintf(buf + len, "0 - normal mode\n");
306 break;
307 case SCA3000_MEAS_MODE_MOT_DET:
308 len += sprintf(buf + len, "3 - motion detection\n");
309 break;
310 case SCA3000_MEAS_MODE_OP_1:
311 switch (st->info->option_mode_1) {
312 case SCA3000_OP_MODE_NARROW:
313 len += sprintf(buf + len, "1 - narrow mode\n");
314 break;
315 case SCA3000_OP_MODE_BYPASS:
316 len += sprintf(buf + len, "1 - bypass mode\n");
317 break;
318 }
319 break;
320 case SCA3000_MEAS_MODE_OP_2:
321 switch (st->info->option_mode_2) {
322 case SCA3000_OP_MODE_WIDE:
323 len += sprintf(buf + len, "2 - wide mode\n");
324 break;
325 }
326 break;
327 }
328
329 error_ret:
330 mutex_unlock(&st->lock);
331
332 return ret ? ret : len;
333 }
334
335 /**
336 * sca3000_store_measurement_mode() set the current mode
337 **/
338 static ssize_t
sca3000_store_measurement_mode(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)339 sca3000_store_measurement_mode(struct device *dev,
340 struct device_attribute *attr,
341 const char *buf,
342 size_t len)
343 {
344 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
345 struct sca3000_state *st = iio_priv(indio_dev);
346 int ret;
347 u8 mask = 0x03;
348 u8 val;
349
350 mutex_lock(&st->lock);
351 ret = kstrtou8(buf, 10, &val);
352 if (ret)
353 goto error_ret;
354 if (val > 3) {
355 ret = -EINVAL;
356 goto error_ret;
357 }
358 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
359 if (ret)
360 goto error_ret;
361 st->rx[0] &= ~mask;
362 st->rx[0] |= (val & mask);
363 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE, st->rx[0]);
364 if (ret)
365 goto error_ret;
366 mutex_unlock(&st->lock);
367
368 return len;
369
370 error_ret:
371 mutex_unlock(&st->lock);
372
373 return ret;
374 }
375
376 /*
377 * Not even vaguely standard attributes so defined here rather than
378 * in the relevant IIO core headers
379 */
380 static IIO_DEVICE_ATTR(measurement_mode_available, S_IRUGO,
381 sca3000_show_available_measurement_modes,
382 NULL, 0);
383
384 static IIO_DEVICE_ATTR(measurement_mode, S_IRUGO | S_IWUSR,
385 sca3000_show_measurement_mode,
386 sca3000_store_measurement_mode,
387 0);
388
389 /* More standard attributes */
390
391 static IIO_DEVICE_ATTR(revision, S_IRUGO, sca3000_show_rev, NULL, 0);
392
393 static const struct iio_event_spec sca3000_event = {
394 .type = IIO_EV_TYPE_MAG,
395 .dir = IIO_EV_DIR_RISING,
396 .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
397 };
398
399 #define SCA3000_CHAN(index, mod) \
400 { \
401 .type = IIO_ACCEL, \
402 .modified = 1, \
403 .channel2 = mod, \
404 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
405 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
406 .address = index, \
407 .scan_index = index, \
408 .scan_type = { \
409 .sign = 's', \
410 .realbits = 11, \
411 .storagebits = 16, \
412 .shift = 5, \
413 }, \
414 .event_spec = &sca3000_event, \
415 .num_event_specs = 1, \
416 }
417
418 static const struct iio_chan_spec sca3000_channels[] = {
419 SCA3000_CHAN(0, IIO_MOD_X),
420 SCA3000_CHAN(1, IIO_MOD_Y),
421 SCA3000_CHAN(2, IIO_MOD_Z),
422 };
423
424 static const struct iio_chan_spec sca3000_channels_with_temp[] = {
425 SCA3000_CHAN(0, IIO_MOD_X),
426 SCA3000_CHAN(1, IIO_MOD_Y),
427 SCA3000_CHAN(2, IIO_MOD_Z),
428 {
429 .type = IIO_TEMP,
430 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
431 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
432 BIT(IIO_CHAN_INFO_OFFSET),
433 /* No buffer support */
434 .scan_index = -1,
435 },
436 };
437
438 static u8 sca3000_addresses[3][3] = {
439 [0] = {SCA3000_REG_ADDR_X_MSB, SCA3000_REG_CTRL_SEL_MD_X_TH,
440 SCA3000_MD_CTRL_OR_X},
441 [1] = {SCA3000_REG_ADDR_Y_MSB, SCA3000_REG_CTRL_SEL_MD_Y_TH,
442 SCA3000_MD_CTRL_OR_Y},
443 [2] = {SCA3000_REG_ADDR_Z_MSB, SCA3000_REG_CTRL_SEL_MD_Z_TH,
444 SCA3000_MD_CTRL_OR_Z},
445 };
446
sca3000_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)447 static int sca3000_read_raw(struct iio_dev *indio_dev,
448 struct iio_chan_spec const *chan,
449 int *val,
450 int *val2,
451 long mask)
452 {
453 struct sca3000_state *st = iio_priv(indio_dev);
454 int ret;
455 u8 address;
456
457 switch (mask) {
458 case IIO_CHAN_INFO_RAW:
459 mutex_lock(&st->lock);
460 if (chan->type == IIO_ACCEL) {
461 if (st->mo_det_use_count) {
462 mutex_unlock(&st->lock);
463 return -EBUSY;
464 }
465 address = sca3000_addresses[chan->address][0];
466 ret = sca3000_read_data_short(st, address, 2);
467 if (ret < 0) {
468 mutex_unlock(&st->lock);
469 return ret;
470 }
471 *val = (be16_to_cpup((__be16 *)st->rx) >> 3) & 0x1FFF;
472 *val = ((*val) << (sizeof(*val) * 8 - 13)) >>
473 (sizeof(*val) * 8 - 13);
474 } else {
475 /* get the temperature when available */
476 ret = sca3000_read_data_short(st,
477 SCA3000_REG_ADDR_TEMP_MSB,
478 2);
479 if (ret < 0) {
480 mutex_unlock(&st->lock);
481 return ret;
482 }
483 *val = ((st->rx[0] & 0x3F) << 3) |
484 ((st->rx[1] & 0xE0) >> 5);
485 }
486 mutex_unlock(&st->lock);
487 return IIO_VAL_INT;
488 case IIO_CHAN_INFO_SCALE:
489 *val = 0;
490 if (chan->type == IIO_ACCEL)
491 *val2 = st->info->scale;
492 else /* temperature */
493 *val2 = 555556;
494 return IIO_VAL_INT_PLUS_MICRO;
495 case IIO_CHAN_INFO_OFFSET:
496 *val = -214;
497 *val2 = 600000;
498 return IIO_VAL_INT_PLUS_MICRO;
499 default:
500 return -EINVAL;
501 }
502 }
503
504 /**
505 * sca3000_read_av_freq() sysfs function to get available frequencies
506 *
507 * The later modes are only relevant to the ring buffer - and depend on current
508 * mode. Note that data sheet gives rather wide tolerances for these so integer
509 * division will give good enough answer and not all chips have them specified
510 * at all.
511 **/
sca3000_read_av_freq(struct device * dev,struct device_attribute * attr,char * buf)512 static ssize_t sca3000_read_av_freq(struct device *dev,
513 struct device_attribute *attr,
514 char *buf)
515 {
516 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
517 struct sca3000_state *st = iio_priv(indio_dev);
518 int len = 0, ret, val;
519
520 mutex_lock(&st->lock);
521 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
522 val = st->rx[0];
523 mutex_unlock(&st->lock);
524 if (ret)
525 goto error_ret;
526
527 switch (val & 0x03) {
528 case SCA3000_MEAS_MODE_NORMAL:
529 len += sprintf(buf + len, "%d %d %d\n",
530 st->info->measurement_mode_freq,
531 st->info->measurement_mode_freq / 2,
532 st->info->measurement_mode_freq / 4);
533 break;
534 case SCA3000_MEAS_MODE_OP_1:
535 len += sprintf(buf + len, "%d %d %d\n",
536 st->info->option_mode_1_freq,
537 st->info->option_mode_1_freq / 2,
538 st->info->option_mode_1_freq / 4);
539 break;
540 case SCA3000_MEAS_MODE_OP_2:
541 len += sprintf(buf + len, "%d %d %d\n",
542 st->info->option_mode_2_freq,
543 st->info->option_mode_2_freq / 2,
544 st->info->option_mode_2_freq / 4);
545 break;
546 }
547 return len;
548 error_ret:
549 return ret;
550 }
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 /**
868 * sca3000_query_free_fall_mode() is free fall mode enabled
869 **/
sca3000_query_free_fall_mode(struct device * dev,struct device_attribute * attr,char * buf)870 static ssize_t sca3000_query_free_fall_mode(struct device *dev,
871 struct device_attribute *attr,
872 char *buf)
873 {
874 int ret;
875 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
876 struct sca3000_state *st = iio_priv(indio_dev);
877 int val;
878
879 mutex_lock(&st->lock);
880 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
881 val = st->rx[0];
882 mutex_unlock(&st->lock);
883 if (ret < 0)
884 return ret;
885 return sprintf(buf, "%d\n", !!(val & SCA3000_FREE_FALL_DETECT));
886 }
887
888 /**
889 * sca3000_set_free_fall_mode() simple on off control for free fall int
890 *
891 * In these chips the free fall detector should send an interrupt if
892 * the device falls more than 25cm. This has not been tested due
893 * to fragile wiring.
894 **/
sca3000_set_free_fall_mode(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)895 static ssize_t sca3000_set_free_fall_mode(struct device *dev,
896 struct device_attribute *attr,
897 const char *buf,
898 size_t len)
899 {
900 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
901 struct sca3000_state *st = iio_priv(indio_dev);
902 u8 val;
903 int ret;
904 u8 protect_mask = SCA3000_FREE_FALL_DETECT;
905
906 mutex_lock(&st->lock);
907 ret = kstrtou8(buf, 10, &val);
908 if (ret)
909 goto error_ret;
910
911 /* read current value of mode register */
912 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
913 if (ret)
914 goto error_ret;
915
916 /* if off and should be on */
917 if (val && !(st->rx[0] & protect_mask))
918 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
919 (st->rx[0] | SCA3000_FREE_FALL_DETECT));
920 /* if on and should be off */
921 else if (!val && (st->rx[0] & protect_mask))
922 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
923 (st->rx[0] & ~protect_mask));
924 error_ret:
925 mutex_unlock(&st->lock);
926
927 return ret ? ret : len;
928 }
929
930 /**
931 * sca3000_write_event_config() simple on off control for motion detector
932 *
933 * This is a per axis control, but enabling any will result in the
934 * motion detector unit being enabled.
935 * N.B. enabling motion detector stops normal data acquisition.
936 * There is a complexity in knowing which mode to return to when
937 * this mode is disabled. Currently normal mode is assumed.
938 **/
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)939 static int sca3000_write_event_config(struct iio_dev *indio_dev,
940 const struct iio_chan_spec *chan,
941 enum iio_event_type type,
942 enum iio_event_direction dir,
943 int state)
944 {
945 struct sca3000_state *st = iio_priv(indio_dev);
946 int ret, ctrlval;
947 u8 protect_mask = 0x03;
948 int num = chan->channel2;
949
950 mutex_lock(&st->lock);
951 /*
952 * First read the motion detector config to find out if
953 * this axis is on
954 */
955 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL);
956 if (ret < 0)
957 goto exit_point;
958 ctrlval = ret;
959 /* if off and should be on */
960 if (state && !(ctrlval & sca3000_addresses[num][2])) {
961 ret = sca3000_write_ctrl_reg(st,
962 SCA3000_REG_CTRL_SEL_MD_CTRL,
963 ctrlval |
964 sca3000_addresses[num][2]);
965 if (ret)
966 goto exit_point;
967 st->mo_det_use_count++;
968 } else if (!state && (ctrlval & sca3000_addresses[num][2])) {
969 ret = sca3000_write_ctrl_reg(st,
970 SCA3000_REG_CTRL_SEL_MD_CTRL,
971 ctrlval &
972 ~(sca3000_addresses[num][2]));
973 if (ret)
974 goto exit_point;
975 st->mo_det_use_count--;
976 }
977
978 /* read current value of mode register */
979 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
980 if (ret)
981 goto exit_point;
982 /* if off and should be on */
983 if ((st->mo_det_use_count) &&
984 ((st->rx[0] & protect_mask) != SCA3000_MEAS_MODE_MOT_DET))
985 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
986 (st->rx[0] & ~protect_mask)
987 | SCA3000_MEAS_MODE_MOT_DET);
988 /* if on and should be off */
989 else if (!(st->mo_det_use_count) &&
990 ((st->rx[0] & protect_mask) == SCA3000_MEAS_MODE_MOT_DET))
991 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
992 (st->rx[0] & ~protect_mask));
993 exit_point:
994 mutex_unlock(&st->lock);
995
996 return ret;
997 }
998
999 /* Free fall detector related event attribute */
1000 static IIO_DEVICE_ATTR_NAMED(accel_xayaz_mag_falling_en,
1001 in_accel_x & y & z_mag_falling_en,
1002 S_IRUGO | S_IWUSR,
1003 sca3000_query_free_fall_mode,
1004 sca3000_set_free_fall_mode,
1005 0);
1006
1007 static IIO_CONST_ATTR_NAMED(accel_xayaz_mag_falling_period,
1008 in_accel_x & y & z_mag_falling_period,
1009 "0.226");
1010
1011 static struct attribute *sca3000_event_attributes[] = {
1012 &iio_dev_attr_accel_xayaz_mag_falling_en.dev_attr.attr,
1013 &iio_const_attr_accel_xayaz_mag_falling_period.dev_attr.attr,
1014 NULL,
1015 };
1016
1017 static struct attribute_group sca3000_event_attribute_group = {
1018 .attrs = sca3000_event_attributes,
1019 .name = "events",
1020 };
1021
1022 /**
1023 * sca3000_clean_setup() get the device into a predictable state
1024 *
1025 * Devices use flash memory to store many of the register values
1026 * and hence can come up in somewhat unpredictable states.
1027 * Hence reset everything on driver load.
1028 **/
sca3000_clean_setup(struct sca3000_state * st)1029 static int sca3000_clean_setup(struct sca3000_state *st)
1030 {
1031 int ret;
1032
1033 mutex_lock(&st->lock);
1034 /* Ensure all interrupts have been acknowledged */
1035 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_STATUS, 1);
1036 if (ret)
1037 goto error_ret;
1038
1039 /* Turn off all motion detection channels */
1040 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL);
1041 if (ret < 0)
1042 goto error_ret;
1043 ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL,
1044 ret & SCA3000_MD_CTRL_PROT_MASK);
1045 if (ret)
1046 goto error_ret;
1047
1048 /* Disable ring buffer */
1049 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);
1050 ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL,
1051 (ret & SCA3000_OUT_CTRL_PROT_MASK)
1052 | SCA3000_OUT_CTRL_BUF_X_EN
1053 | SCA3000_OUT_CTRL_BUF_Y_EN
1054 | SCA3000_OUT_CTRL_BUF_Z_EN
1055 | SCA3000_OUT_CTRL_BUF_DIV_4);
1056 if (ret)
1057 goto error_ret;
1058 /* Enable interrupts, relevant to mode and set up as active low */
1059 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_MASK, 1);
1060 if (ret)
1061 goto error_ret;
1062 ret = sca3000_write_reg(st,
1063 SCA3000_REG_ADDR_INT_MASK,
1064 (ret & SCA3000_INT_MASK_PROT_MASK)
1065 | SCA3000_INT_MASK_ACTIVE_LOW);
1066 if (ret)
1067 goto error_ret;
1068 /*
1069 * Select normal measurement mode, free fall off, ring off
1070 * Ring in 12 bit mode - it is fine to overwrite reserved bits 3,5
1071 * as that occurs in one of the example on the datasheet
1072 */
1073 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
1074 if (ret)
1075 goto error_ret;
1076 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
1077 (st->rx[0] & SCA3000_MODE_PROT_MASK));
1078 st->bpse = 11;
1079
1080 error_ret:
1081 mutex_unlock(&st->lock);
1082 return ret;
1083 }
1084
1085 static const struct iio_info sca3000_info = {
1086 .attrs = &sca3000_attribute_group,
1087 .read_raw = &sca3000_read_raw,
1088 .event_attrs = &sca3000_event_attribute_group,
1089 .read_event_value = &sca3000_read_thresh,
1090 .write_event_value = &sca3000_write_thresh,
1091 .read_event_config = &sca3000_read_event_config,
1092 .write_event_config = &sca3000_write_event_config,
1093 .driver_module = THIS_MODULE,
1094 };
1095
sca3000_probe(struct spi_device * spi)1096 static int sca3000_probe(struct spi_device *spi)
1097 {
1098 int ret;
1099 struct sca3000_state *st;
1100 struct iio_dev *indio_dev;
1101
1102 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
1103 if (!indio_dev)
1104 return -ENOMEM;
1105
1106 st = iio_priv(indio_dev);
1107 spi_set_drvdata(spi, indio_dev);
1108 st->us = spi;
1109 mutex_init(&st->lock);
1110 st->info = &sca3000_spi_chip_info_tbl[spi_get_device_id(spi)
1111 ->driver_data];
1112
1113 indio_dev->dev.parent = &spi->dev;
1114 indio_dev->name = spi_get_device_id(spi)->name;
1115 indio_dev->info = &sca3000_info;
1116 if (st->info->temp_output) {
1117 indio_dev->channels = sca3000_channels_with_temp;
1118 indio_dev->num_channels =
1119 ARRAY_SIZE(sca3000_channels_with_temp);
1120 } else {
1121 indio_dev->channels = sca3000_channels;
1122 indio_dev->num_channels = ARRAY_SIZE(sca3000_channels);
1123 }
1124 indio_dev->modes = INDIO_DIRECT_MODE;
1125
1126 sca3000_configure_ring(indio_dev);
1127 ret = iio_device_register(indio_dev);
1128 if (ret < 0)
1129 return ret;
1130
1131 if (spi->irq) {
1132 ret = request_threaded_irq(spi->irq,
1133 NULL,
1134 &sca3000_event_handler,
1135 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1136 "sca3000",
1137 indio_dev);
1138 if (ret)
1139 goto error_unregister_dev;
1140 }
1141 sca3000_register_ring_funcs(indio_dev);
1142 ret = sca3000_clean_setup(st);
1143 if (ret)
1144 goto error_free_irq;
1145 return 0;
1146
1147 error_free_irq:
1148 if (spi->irq)
1149 free_irq(spi->irq, indio_dev);
1150 error_unregister_dev:
1151 iio_device_unregister(indio_dev);
1152 return ret;
1153 }
1154
sca3000_stop_all_interrupts(struct sca3000_state * st)1155 static int sca3000_stop_all_interrupts(struct sca3000_state *st)
1156 {
1157 int ret;
1158
1159 mutex_lock(&st->lock);
1160 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_MASK, 1);
1161 if (ret)
1162 goto error_ret;
1163 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_INT_MASK,
1164 (st->rx[0] &
1165 ~(SCA3000_INT_MASK_RING_THREE_QUARTER |
1166 SCA3000_INT_MASK_RING_HALF |
1167 SCA3000_INT_MASK_ALL_INTS)));
1168 error_ret:
1169 mutex_unlock(&st->lock);
1170 return ret;
1171 }
1172
sca3000_remove(struct spi_device * spi)1173 static int sca3000_remove(struct spi_device *spi)
1174 {
1175 struct iio_dev *indio_dev = spi_get_drvdata(spi);
1176 struct sca3000_state *st = iio_priv(indio_dev);
1177
1178 /* Must ensure no interrupts can be generated after this! */
1179 sca3000_stop_all_interrupts(st);
1180 if (spi->irq)
1181 free_irq(spi->irq, indio_dev);
1182 iio_device_unregister(indio_dev);
1183 sca3000_unconfigure_ring(indio_dev);
1184
1185 return 0;
1186 }
1187
1188 static const struct spi_device_id sca3000_id[] = {
1189 {"sca3000_d01", d01},
1190 {"sca3000_e02", e02},
1191 {"sca3000_e04", e04},
1192 {"sca3000_e05", e05},
1193 {}
1194 };
1195 MODULE_DEVICE_TABLE(spi, sca3000_id);
1196
1197 static struct spi_driver sca3000_driver = {
1198 .driver = {
1199 .name = "sca3000",
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