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1 /*
2  * ADIS16240 Programmable Impact Sensor and Recorder driver
3  *
4  * Copyright 2010 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later.
7  */
8 
9 #include <linux/interrupt.h>
10 #include <linux/irq.h>
11 #include <linux/gpio.h>
12 #include <linux/delay.h>
13 #include <linux/mutex.h>
14 #include <linux/device.h>
15 #include <linux/kernel.h>
16 #include <linux/spi/spi.h>
17 #include <linux/slab.h>
18 #include <linux/sysfs.h>
19 #include <linux/list.h>
20 #include <linux/module.h>
21 
22 #include "../iio.h"
23 #include "../sysfs.h"
24 #include "../buffer.h"
25 
26 #include "adis16240.h"
27 
28 #define DRIVER_NAME		"adis16240"
29 
30 static int adis16240_check_status(struct iio_dev *indio_dev);
31 
32 /**
33  * adis16240_spi_write_reg_8() - write single byte to a register
34  * @indio_dev: iio_dev associated with device
35  * @reg_address: the address of the register to be written
36  * @val: the value to write
37  **/
adis16240_spi_write_reg_8(struct iio_dev * indio_dev,u8 reg_address,u8 val)38 static int adis16240_spi_write_reg_8(struct iio_dev *indio_dev,
39 				     u8 reg_address,
40 				     u8 val)
41 {
42 	int ret;
43 	struct adis16240_state *st = iio_priv(indio_dev);
44 
45 	mutex_lock(&st->buf_lock);
46 	st->tx[0] = ADIS16240_WRITE_REG(reg_address);
47 	st->tx[1] = val;
48 
49 	ret = spi_write(st->us, st->tx, 2);
50 	mutex_unlock(&st->buf_lock);
51 
52 	return ret;
53 }
54 
55 /**
56  * adis16240_spi_write_reg_16() - write 2 bytes to a pair of registers
57  * @indio_dev: iio_dev for this device
58  * @reg_address: the address of the lower of the two registers. Second register
59  *               is assumed to have address one greater.
60  * @val: value to be written
61  **/
adis16240_spi_write_reg_16(struct iio_dev * indio_dev,u8 lower_reg_address,u16 value)62 static int adis16240_spi_write_reg_16(struct iio_dev *indio_dev,
63 				      u8 lower_reg_address,
64 				      u16 value)
65 {
66 	int ret;
67 	struct spi_message msg;
68 	struct adis16240_state *st = iio_priv(indio_dev);
69 	struct spi_transfer xfers[] = {
70 		{
71 			.tx_buf = st->tx,
72 			.bits_per_word = 8,
73 			.len = 2,
74 			.cs_change = 1,
75 			.delay_usecs = 35,
76 		}, {
77 			.tx_buf = st->tx + 2,
78 			.bits_per_word = 8,
79 			.len = 2,
80 			.delay_usecs = 35,
81 		},
82 	};
83 
84 	mutex_lock(&st->buf_lock);
85 	st->tx[0] = ADIS16240_WRITE_REG(lower_reg_address);
86 	st->tx[1] = value & 0xFF;
87 	st->tx[2] = ADIS16240_WRITE_REG(lower_reg_address + 1);
88 	st->tx[3] = (value >> 8) & 0xFF;
89 
90 	spi_message_init(&msg);
91 	spi_message_add_tail(&xfers[0], &msg);
92 	spi_message_add_tail(&xfers[1], &msg);
93 	ret = spi_sync(st->us, &msg);
94 	mutex_unlock(&st->buf_lock);
95 
96 	return ret;
97 }
98 
99 /**
100  * adis16240_spi_read_reg_16() - read 2 bytes from a 16-bit register
101  * @indio_dev: iio_dev for this device
102  * @reg_address: the address of the lower of the two registers. Second register
103  *               is assumed to have address one greater.
104  * @val: somewhere to pass back the value read
105  **/
adis16240_spi_read_reg_16(struct iio_dev * indio_dev,u8 lower_reg_address,u16 * val)106 static int adis16240_spi_read_reg_16(struct iio_dev *indio_dev,
107 		u8 lower_reg_address,
108 		u16 *val)
109 {
110 	struct spi_message msg;
111 	struct adis16240_state *st = iio_priv(indio_dev);
112 	int ret;
113 	struct spi_transfer xfers[] = {
114 		{
115 			.tx_buf = st->tx,
116 			.bits_per_word = 8,
117 			.len = 2,
118 			.cs_change = 1,
119 			.delay_usecs = 35,
120 		}, {
121 			.rx_buf = st->rx,
122 			.bits_per_word = 8,
123 			.len = 2,
124 			.cs_change = 1,
125 			.delay_usecs = 35,
126 		},
127 	};
128 
129 	mutex_lock(&st->buf_lock);
130 	st->tx[0] = ADIS16240_READ_REG(lower_reg_address);
131 	st->tx[1] = 0;
132 	st->tx[2] = 0;
133 	st->tx[3] = 0;
134 
135 	spi_message_init(&msg);
136 	spi_message_add_tail(&xfers[0], &msg);
137 	spi_message_add_tail(&xfers[1], &msg);
138 	ret = spi_sync(st->us, &msg);
139 	if (ret) {
140 		dev_err(&st->us->dev,
141 			"problem when reading 16 bit register 0x%02X",
142 			lower_reg_address);
143 		goto error_ret;
144 	}
145 	*val = (st->rx[0] << 8) | st->rx[1];
146 
147 error_ret:
148 	mutex_unlock(&st->buf_lock);
149 	return ret;
150 }
151 
adis16240_spi_read_signed(struct device * dev,struct device_attribute * attr,char * buf,unsigned bits)152 static ssize_t adis16240_spi_read_signed(struct device *dev,
153 		struct device_attribute *attr,
154 		char *buf,
155 		unsigned bits)
156 {
157 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
158 	int ret;
159 	s16 val = 0;
160 	unsigned shift = 16 - bits;
161 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
162 
163 	ret = adis16240_spi_read_reg_16(indio_dev,
164 					this_attr->address, (u16 *)&val);
165 	if (ret)
166 		return ret;
167 
168 	if (val & ADIS16240_ERROR_ACTIVE)
169 		adis16240_check_status(indio_dev);
170 
171 	val = ((s16)(val << shift) >> shift);
172 	return sprintf(buf, "%d\n", val);
173 }
174 
adis16240_read_12bit_signed(struct device * dev,struct device_attribute * attr,char * buf)175 static ssize_t adis16240_read_12bit_signed(struct device *dev,
176 		struct device_attribute *attr,
177 		char *buf)
178 {
179 	ssize_t ret;
180 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
181 
182 	/* Take the iio_dev status lock */
183 	mutex_lock(&indio_dev->mlock);
184 	ret =  adis16240_spi_read_signed(dev, attr, buf, 12);
185 	mutex_unlock(&indio_dev->mlock);
186 
187 	return ret;
188 }
189 
adis16240_reset(struct iio_dev * indio_dev)190 static int adis16240_reset(struct iio_dev *indio_dev)
191 {
192 	int ret;
193 	ret = adis16240_spi_write_reg_8(indio_dev,
194 			ADIS16240_GLOB_CMD,
195 			ADIS16240_GLOB_CMD_SW_RESET);
196 	if (ret)
197 		dev_err(&indio_dev->dev, "problem resetting device");
198 
199 	return ret;
200 }
201 
adis16240_write_reset(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)202 static ssize_t adis16240_write_reset(struct device *dev,
203 		struct device_attribute *attr,
204 		const char *buf, size_t len)
205 {
206 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
207 
208 	if (len < 1)
209 		return -EINVAL;
210 	switch (buf[0]) {
211 	case '1':
212 	case 'y':
213 	case 'Y':
214 		return adis16240_reset(indio_dev);
215 	}
216 	return -EINVAL;
217 }
218 
adis16240_set_irq(struct iio_dev * indio_dev,bool enable)219 int adis16240_set_irq(struct iio_dev *indio_dev, bool enable)
220 {
221 	int ret = 0;
222 	u16 msc;
223 
224 	ret = adis16240_spi_read_reg_16(indio_dev,
225 					ADIS16240_MSC_CTRL, &msc);
226 	if (ret)
227 		goto error_ret;
228 
229 	msc |= ADIS16240_MSC_CTRL_ACTIVE_HIGH;
230 	msc &= ~ADIS16240_MSC_CTRL_DATA_RDY_DIO2;
231 	if (enable)
232 		msc |= ADIS16240_MSC_CTRL_DATA_RDY_EN;
233 	else
234 		msc &= ~ADIS16240_MSC_CTRL_DATA_RDY_EN;
235 
236 	ret = adis16240_spi_write_reg_16(indio_dev,
237 					 ADIS16240_MSC_CTRL, msc);
238 
239 error_ret:
240 	return ret;
241 }
242 
adis16240_self_test(struct iio_dev * indio_dev)243 static int adis16240_self_test(struct iio_dev *indio_dev)
244 {
245 	int ret;
246 	ret = adis16240_spi_write_reg_16(indio_dev,
247 			ADIS16240_MSC_CTRL,
248 			ADIS16240_MSC_CTRL_SELF_TEST_EN);
249 	if (ret) {
250 		dev_err(&indio_dev->dev, "problem starting self test");
251 		goto err_ret;
252 	}
253 
254 	msleep(ADIS16240_STARTUP_DELAY);
255 
256 	adis16240_check_status(indio_dev);
257 
258 err_ret:
259 	return ret;
260 }
261 
adis16240_check_status(struct iio_dev * indio_dev)262 static int adis16240_check_status(struct iio_dev *indio_dev)
263 {
264 	u16 status;
265 	int ret;
266 	struct device *dev = &indio_dev->dev;
267 
268 	ret = adis16240_spi_read_reg_16(indio_dev,
269 					ADIS16240_DIAG_STAT, &status);
270 
271 	if (ret < 0) {
272 		dev_err(dev, "Reading status failed\n");
273 		goto error_ret;
274 	}
275 
276 	ret = status & 0x2F;
277 	if (status & ADIS16240_DIAG_STAT_PWRON_FAIL)
278 		dev_err(dev, "Power-on, self-test fail\n");
279 	if (status & ADIS16240_DIAG_STAT_SPI_FAIL)
280 		dev_err(dev, "SPI failure\n");
281 	if (status & ADIS16240_DIAG_STAT_FLASH_UPT)
282 		dev_err(dev, "Flash update failed\n");
283 	if (status & ADIS16240_DIAG_STAT_POWER_HIGH)
284 		dev_err(dev, "Power supply above 3.625V\n");
285 	if (status & ADIS16240_DIAG_STAT_POWER_LOW)
286 		dev_err(dev, "Power supply below 2.225V\n");
287 
288 error_ret:
289 	return ret;
290 }
291 
adis16240_initial_setup(struct iio_dev * indio_dev)292 static int adis16240_initial_setup(struct iio_dev *indio_dev)
293 {
294 	int ret;
295 	struct device *dev = &indio_dev->dev;
296 
297 	/* Disable IRQ */
298 	ret = adis16240_set_irq(indio_dev, false);
299 	if (ret) {
300 		dev_err(dev, "disable irq failed");
301 		goto err_ret;
302 	}
303 
304 	/* Do self test */
305 	ret = adis16240_self_test(indio_dev);
306 	if (ret) {
307 		dev_err(dev, "self test failure");
308 		goto err_ret;
309 	}
310 
311 	/* Read status register to check the result */
312 	ret = adis16240_check_status(indio_dev);
313 	if (ret) {
314 		adis16240_reset(indio_dev);
315 		dev_err(dev, "device not playing ball -> reset");
316 		msleep(ADIS16240_STARTUP_DELAY);
317 		ret = adis16240_check_status(indio_dev);
318 		if (ret) {
319 			dev_err(dev, "giving up");
320 			goto err_ret;
321 		}
322 	}
323 
324 err_ret:
325 	return ret;
326 }
327 
328 static IIO_DEVICE_ATTR(in_accel_xyz_squared_peak_raw, S_IRUGO,
329 		       adis16240_read_12bit_signed, NULL,
330 		       ADIS16240_XYZPEAK_OUT);
331 
332 static IIO_DEVICE_ATTR(reset, S_IWUSR, NULL, adis16240_write_reset, 0);
333 
334 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("4096");
335 
336 enum adis16240_chan {
337 	in_supply,
338 	in_aux,
339 	accel_x,
340 	accel_y,
341 	accel_z,
342 	temp,
343 };
344 
345 static const u8 adis16240_addresses[6][3] = {
346 	[in_supply] = { ADIS16240_SUPPLY_OUT },
347 	[in_aux] = { ADIS16240_AUX_ADC },
348 	[accel_x] = { ADIS16240_XACCL_OUT, ADIS16240_XACCL_OFF,
349 		      ADIS16240_XPEAK_OUT },
350 	[accel_y] = { ADIS16240_YACCL_OUT, ADIS16240_YACCL_OFF,
351 		      ADIS16240_YPEAK_OUT },
352 	[accel_z] = { ADIS16240_ZACCL_OUT, ADIS16240_ZACCL_OFF,
353 		      ADIS16240_ZPEAK_OUT },
354 	[temp] = { ADIS16240_TEMP_OUT },
355 };
356 
adis16240_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)357 static int adis16240_read_raw(struct iio_dev *indio_dev,
358 			      struct iio_chan_spec const *chan,
359 			      int *val, int *val2,
360 			      long mask)
361 {
362 	int ret;
363 	int bits;
364 	u8 addr;
365 	s16 val16;
366 
367 	switch (mask) {
368 	case 0:
369 		mutex_lock(&indio_dev->mlock);
370 		addr = adis16240_addresses[chan->address][0];
371 		ret = adis16240_spi_read_reg_16(indio_dev, addr, &val16);
372 		if (ret) {
373 			mutex_unlock(&indio_dev->mlock);
374 			return ret;
375 		}
376 
377 		if (val16 & ADIS16240_ERROR_ACTIVE) {
378 			ret = adis16240_check_status(indio_dev);
379 			if (ret) {
380 				mutex_unlock(&indio_dev->mlock);
381 				return ret;
382 			}
383 		}
384 		val16 = val16 & ((1 << chan->scan_type.realbits) - 1);
385 		if (chan->scan_type.sign == 's')
386 			val16 = (s16)(val16 <<
387 				      (16 - chan->scan_type.realbits)) >>
388 				(16 - chan->scan_type.realbits);
389 		*val = val16;
390 		mutex_unlock(&indio_dev->mlock);
391 		return IIO_VAL_INT;
392 	case IIO_CHAN_INFO_SCALE:
393 		switch (chan->type) {
394 		case IIO_VOLTAGE:
395 			*val = 0;
396 			if (chan->channel == 0)
397 				*val2 = 4880;
398 			else
399 				return -EINVAL;
400 			return IIO_VAL_INT_PLUS_MICRO;
401 		case IIO_TEMP:
402 			*val = 0;
403 			*val2 = 244000;
404 			return IIO_VAL_INT_PLUS_MICRO;
405 		case IIO_ACCEL:
406 			*val = 0;
407 			*val2 = 504062;
408 			return IIO_VAL_INT_PLUS_MICRO;
409 		default:
410 			return -EINVAL;
411 		}
412 		break;
413 	case IIO_CHAN_INFO_PEAK_SCALE:
414 		*val = 6;
415 		*val2 = 629295;
416 		return IIO_VAL_INT_PLUS_MICRO;
417 	case IIO_CHAN_INFO_OFFSET:
418 		*val = 25;
419 		return IIO_VAL_INT;
420 	case IIO_CHAN_INFO_CALIBBIAS:
421 		bits = 10;
422 		mutex_lock(&indio_dev->mlock);
423 		addr = adis16240_addresses[chan->address][1];
424 		ret = adis16240_spi_read_reg_16(indio_dev, addr, &val16);
425 		if (ret) {
426 			mutex_unlock(&indio_dev->mlock);
427 			return ret;
428 		}
429 		val16 &= (1 << bits) - 1;
430 		val16 = (s16)(val16 << (16 - bits)) >> (16 - bits);
431 		*val = val16;
432 		mutex_unlock(&indio_dev->mlock);
433 		return IIO_VAL_INT;
434 	case IIO_CHAN_INFO_PEAK:
435 		bits = 10;
436 		mutex_lock(&indio_dev->mlock);
437 		addr = adis16240_addresses[chan->address][2];
438 		ret = adis16240_spi_read_reg_16(indio_dev, addr, &val16);
439 		if (ret) {
440 			mutex_unlock(&indio_dev->mlock);
441 			return ret;
442 		}
443 		val16 &= (1 << bits) - 1;
444 		val16 = (s16)(val16 << (16 - bits)) >> (16 - bits);
445 		*val = val16;
446 		mutex_unlock(&indio_dev->mlock);
447 		return IIO_VAL_INT;
448 	}
449 	return -EINVAL;
450 }
451 
adis16240_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)452 static int adis16240_write_raw(struct iio_dev *indio_dev,
453 			       struct iio_chan_spec const *chan,
454 			       int val,
455 			       int val2,
456 			       long mask)
457 {
458 	int bits = 10;
459 	s16 val16;
460 	u8 addr;
461 	switch (mask) {
462 	case IIO_CHAN_INFO_CALIBBIAS:
463 		val16 = val & ((1 << bits) - 1);
464 		addr = adis16240_addresses[chan->address][1];
465 		return adis16240_spi_write_reg_16(indio_dev, addr, val16);
466 	}
467 	return -EINVAL;
468 }
469 
470 static struct iio_chan_spec adis16240_channels[] = {
471 	IIO_CHAN(IIO_VOLTAGE, 0, 1, 0, "supply", 0, 0,
472 		 IIO_CHAN_INFO_SCALE_SEPARATE_BIT,
473 		 in_supply, ADIS16240_SCAN_SUPPLY,
474 		 IIO_ST('u', 10, 16, 0), 0),
475 	IIO_CHAN(IIO_VOLTAGE, 0, 1, 0, NULL, 1, 0,
476 		 0,
477 		 in_aux, ADIS16240_SCAN_AUX_ADC,
478 		 IIO_ST('u', 10, 16, 0), 0),
479 	IIO_CHAN(IIO_ACCEL, 1, 0, 0, NULL, 0, IIO_MOD_X,
480 		 IIO_CHAN_INFO_SCALE_SHARED_BIT |
481 		 IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT,
482 		 accel_x, ADIS16240_SCAN_ACC_X,
483 		 IIO_ST('s', 10, 16, 0), 0),
484 	IIO_CHAN(IIO_ACCEL, 1, 0, 0, NULL, 0, IIO_MOD_Y,
485 		 IIO_CHAN_INFO_SCALE_SHARED_BIT |
486 		 IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT,
487 		 accel_y, ADIS16240_SCAN_ACC_Y,
488 		 IIO_ST('s', 10, 16, 0), 0),
489 	IIO_CHAN(IIO_ACCEL, 1, 0, 0, NULL, 0, IIO_MOD_Z,
490 		 IIO_CHAN_INFO_SCALE_SHARED_BIT |
491 		 IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT,
492 		 accel_z, ADIS16240_SCAN_ACC_Z,
493 		 IIO_ST('s', 10, 16, 0), 0),
494 	IIO_CHAN(IIO_TEMP, 0, 1, 0, NULL, 0, 0,
495 		 IIO_CHAN_INFO_SCALE_SEPARATE_BIT,
496 		 temp, ADIS16240_SCAN_TEMP,
497 		 IIO_ST('u', 10, 16, 0), 0),
498 	IIO_CHAN_SOFT_TIMESTAMP(6)
499 };
500 
501 static struct attribute *adis16240_attributes[] = {
502 	&iio_dev_attr_in_accel_xyz_squared_peak_raw.dev_attr.attr,
503 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
504 	&iio_dev_attr_reset.dev_attr.attr,
505 	NULL
506 };
507 
508 static const struct attribute_group adis16240_attribute_group = {
509 	.attrs = adis16240_attributes,
510 };
511 
512 static const struct iio_info adis16240_info = {
513 	.attrs = &adis16240_attribute_group,
514 	.read_raw = &adis16240_read_raw,
515 	.write_raw = &adis16240_write_raw,
516 	.driver_module = THIS_MODULE,
517 };
518 
adis16240_probe(struct spi_device * spi)519 static int __devinit adis16240_probe(struct spi_device *spi)
520 {
521 	int ret;
522 	struct adis16240_state *st;
523 	struct iio_dev *indio_dev;
524 
525 	/* setup the industrialio driver allocated elements */
526 	indio_dev = iio_allocate_device(sizeof(*st));
527 	if (indio_dev == NULL) {
528 		ret = -ENOMEM;
529 		goto error_ret;
530 	}
531 	st = iio_priv(indio_dev);
532 	/* this is only used for removal purposes */
533 	spi_set_drvdata(spi, indio_dev);
534 
535 	st->us = spi;
536 	mutex_init(&st->buf_lock);
537 
538 	indio_dev->name = spi->dev.driver->name;
539 	indio_dev->dev.parent = &spi->dev;
540 	indio_dev->info = &adis16240_info;
541 	indio_dev->channels = adis16240_channels;
542 	indio_dev->num_channels = ARRAY_SIZE(adis16240_channels);
543 	indio_dev->modes = INDIO_DIRECT_MODE;
544 
545 	ret = adis16240_configure_ring(indio_dev);
546 	if (ret)
547 		goto error_free_dev;
548 
549 	ret = iio_buffer_register(indio_dev,
550 				  adis16240_channels,
551 				  ARRAY_SIZE(adis16240_channels));
552 	if (ret) {
553 		printk(KERN_ERR "failed to initialize the ring\n");
554 		goto error_unreg_ring_funcs;
555 	}
556 
557 	if (spi->irq) {
558 		ret = adis16240_probe_trigger(indio_dev);
559 		if (ret)
560 			goto error_uninitialize_ring;
561 	}
562 
563 	/* Get the device into a sane initial state */
564 	ret = adis16240_initial_setup(indio_dev);
565 	if (ret)
566 		goto error_remove_trigger;
567 	ret = iio_device_register(indio_dev);
568 	if (ret)
569 		goto error_remove_trigger;
570 	return 0;
571 
572 error_remove_trigger:
573 	adis16240_remove_trigger(indio_dev);
574 error_uninitialize_ring:
575 	iio_buffer_unregister(indio_dev);
576 error_unreg_ring_funcs:
577 	adis16240_unconfigure_ring(indio_dev);
578 error_free_dev:
579 	iio_free_device(indio_dev);
580 error_ret:
581 	return ret;
582 }
583 
adis16240_remove(struct spi_device * spi)584 static int adis16240_remove(struct spi_device *spi)
585 {
586 
587 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
588 
589 	flush_scheduled_work();
590 
591 	iio_device_unregister(indio_dev);
592 	adis16240_remove_trigger(indio_dev);
593 	iio_buffer_unregister(indio_dev);
594 	adis16240_unconfigure_ring(indio_dev);
595 	iio_free_device(indio_dev);
596 
597 	return 0;
598 }
599 
600 static struct spi_driver adis16240_driver = {
601 	.driver = {
602 		.name = "adis16240",
603 		.owner = THIS_MODULE,
604 	},
605 	.probe = adis16240_probe,
606 	.remove = __devexit_p(adis16240_remove),
607 };
608 module_spi_driver(adis16240_driver);
609 
610 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
611 MODULE_DESCRIPTION("Analog Devices Programmable Impact Sensor and Recorder");
612 MODULE_LICENSE("GPL v2");
613 MODULE_ALIAS("spi:adis16240");
614