summaryrefslogtreecommitdiff
path: root/drivers/iio/imu/adis.c
blob: c539dfa3b8d3ed06f6c848ad5f3b431efe7108e1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Common library for ADIS16XXX devices
 *
 * Copyright 2012 Analog Devices Inc.
 *   Author: Lars-Peter Clausen <lars@metafoo.de>
 */

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include <asm/unaligned.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/imu/adis.h>

#define ADIS_MSC_CTRL_DATA_RDY_EN	BIT(2)
#define ADIS_MSC_CTRL_DATA_RDY_POL_HIGH	BIT(1)
#define ADIS_MSC_CTRL_DATA_RDY_DIO2	BIT(0)
#define ADIS_GLOB_CMD_SW_RESET		BIT(7)

/**
 * __adis_write_reg() - write N bytes to register (unlocked version)
 * @adis: The adis device
 * @reg: The address of the lower of the two registers
 * @value: The value to write to device (up to 4 bytes)
 * @size: The size of the @value (in bytes)
 */
int __adis_write_reg(struct adis *adis, unsigned int reg,
	unsigned int value, unsigned int size)
{
	unsigned int page = reg / ADIS_PAGE_SIZE;
	int ret, i;
	struct spi_message msg;
	struct spi_transfer xfers[] = {
		{
			.tx_buf = adis->tx,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay.value = adis->data->write_delay,
			.delay.unit = SPI_DELAY_UNIT_USECS,
			.cs_change_delay.value = adis->data->cs_change_delay,
			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
		}, {
			.tx_buf = adis->tx + 2,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay.value = adis->data->write_delay,
			.delay.unit = SPI_DELAY_UNIT_USECS,
			.cs_change_delay.value = adis->data->cs_change_delay,
			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
		}, {
			.tx_buf = adis->tx + 4,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay.value = adis->data->write_delay,
			.delay.unit = SPI_DELAY_UNIT_USECS,
			.cs_change_delay.value = adis->data->cs_change_delay,
			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
		}, {
			.tx_buf = adis->tx + 6,
			.bits_per_word = 8,
			.len = 2,
			.delay.value = adis->data->write_delay,
			.delay.unit = SPI_DELAY_UNIT_USECS,
		}, {
			.tx_buf = adis->tx + 8,
			.bits_per_word = 8,
			.len = 2,
			.delay.value = adis->data->write_delay,
			.delay.unit = SPI_DELAY_UNIT_USECS,
		},
	};

	spi_message_init(&msg);

	if (adis->current_page != page) {
		adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
		adis->tx[1] = page;
		spi_message_add_tail(&xfers[0], &msg);
	}

	switch (size) {
	case 4:
		adis->tx[8] = ADIS_WRITE_REG(reg + 3);
		adis->tx[9] = (value >> 24) & 0xff;
		adis->tx[6] = ADIS_WRITE_REG(reg + 2);
		adis->tx[7] = (value >> 16) & 0xff;
		/* fall through */
	case 2:
		adis->tx[4] = ADIS_WRITE_REG(reg + 1);
		adis->tx[5] = (value >> 8) & 0xff;
		/* fall through */
	case 1:
		adis->tx[2] = ADIS_WRITE_REG(reg);
		adis->tx[3] = value & 0xff;
		break;
	default:
		return -EINVAL;
	}

	xfers[size].cs_change = 0;

	for (i = 1; i <= size; i++)
		spi_message_add_tail(&xfers[i], &msg);

	ret = spi_sync(adis->spi, &msg);
	if (ret) {
		dev_err(&adis->spi->dev, "Failed to write register 0x%02X: %d\n",
				reg, ret);
	} else {
		adis->current_page = page;
	}

	return ret;
}
EXPORT_SYMBOL_GPL(__adis_write_reg);

/**
 * __adis_read_reg() - read N bytes from register (unlocked version)
 * @adis: The adis device
 * @reg: The address of the lower of the two registers
 * @val: The value read back from the device
 * @size: The size of the @val buffer
 */
int __adis_read_reg(struct adis *adis, unsigned int reg,
	unsigned int *val, unsigned int size)
{
	unsigned int page = reg / ADIS_PAGE_SIZE;
	struct spi_message msg;
	int ret;
	struct spi_transfer xfers[] = {
		{
			.tx_buf = adis->tx,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay.value = adis->data->write_delay,
			.delay.unit = SPI_DELAY_UNIT_USECS,
			.cs_change_delay.value = adis->data->cs_change_delay,
			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
		}, {
			.tx_buf = adis->tx + 2,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay.value = adis->data->read_delay,
			.delay.unit = SPI_DELAY_UNIT_USECS,
			.cs_change_delay.value = adis->data->cs_change_delay,
			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
		}, {
			.tx_buf = adis->tx + 4,
			.rx_buf = adis->rx,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay.value = adis->data->read_delay,
			.delay.unit = SPI_DELAY_UNIT_USECS,
			.cs_change_delay.value = adis->data->cs_change_delay,
			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
		}, {
			.rx_buf = adis->rx + 2,
			.bits_per_word = 8,
			.len = 2,
			.delay.value = adis->data->read_delay,
			.delay.unit = SPI_DELAY_UNIT_USECS,
		},
	};

	spi_message_init(&msg);

	if (adis->current_page != page) {
		adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
		adis->tx[1] = page;
		spi_message_add_tail(&xfers[0], &msg);
	}

	switch (size) {
	case 4:
		adis->tx[2] = ADIS_READ_REG(reg + 2);
		adis->tx[3] = 0;
		spi_message_add_tail(&xfers[1], &msg);
		/* fall through */
	case 2:
		adis->tx[4] = ADIS_READ_REG(reg);
		adis->tx[5] = 0;
		spi_message_add_tail(&xfers[2], &msg);
		spi_message_add_tail(&xfers[3], &msg);
		break;
	default:
		return -EINVAL;
	}

	ret = spi_sync(adis->spi, &msg);
	if (ret) {
		dev_err(&adis->spi->dev, "Failed to read register 0x%02X: %d\n",
				reg, ret);
		return ret;
	} else {
		adis->current_page = page;
	}

	switch (size) {
	case 4:
		*val = get_unaligned_be32(adis->rx);
		break;
	case 2:
		*val = get_unaligned_be16(adis->rx + 2);
		break;
	}

	return ret;
}
EXPORT_SYMBOL_GPL(__adis_read_reg);
/**
 * __adis_update_bits_base() - ADIS Update bits function - Unlocked version
 * @adis: The adis device
 * @reg: The address of the lower of the two registers
 * @mask: Bitmask to change
 * @val: Value to be written
 * @size: Size of the register to update
 *
 * Updates the desired bits of @reg in accordance with @mask and @val.
 */
int __adis_update_bits_base(struct adis *adis, unsigned int reg, const u32 mask,
			    const u32 val, u8 size)
{
	int ret;
	u32 __val;

	ret = __adis_read_reg(adis, reg, &__val, size);
	if (ret)
		return ret;

	__val = (__val & ~mask) | (val & mask);

	return __adis_write_reg(adis, reg, __val, size);
}
EXPORT_SYMBOL_GPL(__adis_update_bits_base);

#ifdef CONFIG_DEBUG_FS

int adis_debugfs_reg_access(struct iio_dev *indio_dev,
	unsigned int reg, unsigned int writeval, unsigned int *readval)
{
	struct adis *adis = iio_device_get_drvdata(indio_dev);

	if (readval) {
		uint16_t val16;
		int ret;

		ret = adis_read_reg_16(adis, reg, &val16);
		if (ret == 0)
			*readval = val16;

		return ret;
	} else {
		return adis_write_reg_16(adis, reg, writeval);
	}
}
EXPORT_SYMBOL(adis_debugfs_reg_access);

#endif

/**
 * adis_enable_irq() - Enable or disable data ready IRQ
 * @adis: The adis device
 * @enable: Whether to enable the IRQ
 *
 * Returns 0 on success, negative error code otherwise
 */
int adis_enable_irq(struct adis *adis, bool enable)
{
	int ret = 0;
	uint16_t msc;

	mutex_lock(&adis->state_lock);

	if (adis->data->enable_irq) {
		ret = adis->data->enable_irq(adis, enable);
		goto out_unlock;
	}

	ret = __adis_read_reg_16(adis, adis->data->msc_ctrl_reg, &msc);
	if (ret)
		goto out_unlock;

	msc |= ADIS_MSC_CTRL_DATA_RDY_POL_HIGH;
	msc &= ~ADIS_MSC_CTRL_DATA_RDY_DIO2;
	if (enable)
		msc |= ADIS_MSC_CTRL_DATA_RDY_EN;
	else
		msc &= ~ADIS_MSC_CTRL_DATA_RDY_EN;

	ret = __adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc);

out_unlock:
	mutex_unlock(&adis->state_lock);
	return ret;
}
EXPORT_SYMBOL(adis_enable_irq);

/**
 * __adis_check_status() - Check the device for error conditions (unlocked)
 * @adis: The adis device
 *
 * Returns 0 on success, a negative error code otherwise
 */
int __adis_check_status(struct adis *adis)
{
	uint16_t status;
	int ret;
	int i;

	ret = __adis_read_reg_16(adis, adis->data->diag_stat_reg, &status);
	if (ret)
		return ret;

	status &= adis->data->status_error_mask;

	if (status == 0)
		return 0;

	for (i = 0; i < 16; ++i) {
		if (status & BIT(i)) {
			dev_err(&adis->spi->dev, "%s.\n",
				adis->data->status_error_msgs[i]);
		}
	}

	return -EIO;
}
EXPORT_SYMBOL_GPL(__adis_check_status);

/**
 * __adis_reset() - Reset the device (unlocked version)
 * @adis: The adis device
 *
 * Returns 0 on success, a negative error code otherwise
 */
int __adis_reset(struct adis *adis)
{
	int ret;
	const struct adis_timeout *timeouts = adis->data->timeouts;

	ret = __adis_write_reg_8(adis, adis->data->glob_cmd_reg,
			ADIS_GLOB_CMD_SW_RESET);
	if (ret) {
		dev_err(&adis->spi->dev, "Failed to reset device: %d\n", ret);
		return ret;
	}

	msleep(timeouts->sw_reset_ms);

	return 0;
}
EXPORT_SYMBOL_GPL(__adis_reset);

static int adis_self_test(struct adis *adis)
{
	int ret;
	const struct adis_timeout *timeouts = adis->data->timeouts;

	ret = __adis_write_reg_16(adis, adis->data->self_test_reg,
				  adis->data->self_test_mask);
	if (ret) {
		dev_err(&adis->spi->dev, "Failed to initiate self test: %d\n",
			ret);
		return ret;
	}

	msleep(timeouts->self_test_ms);

	ret = __adis_check_status(adis);

	if (adis->data->self_test_no_autoclear)
		__adis_write_reg_16(adis, adis->data->self_test_reg, 0x00);

	return ret;
}

/**
 * __adis_initial_startup() - Device initial setup
 * @adis: The adis device
 *
 * The function performs a HW reset via a reset pin that should be specified
 * via GPIOLIB. If no pin is configured a SW reset will be performed.
 * The RST pin for the ADIS devices should be configured as ACTIVE_LOW.
 *
 * After the self-test operation is performed, the function will also check
 * that the product ID is as expected. This assumes that drivers providing
 * 'prod_id_reg' will also provide the 'prod_id'.
 *
 * Returns 0 if the device is operational, a negative error code otherwise.
 *
 * This function should be called early on in the device initialization sequence
 * to ensure that the device is in a sane and known state and that it is usable.
 */
int __adis_initial_startup(struct adis *adis)
{
	const struct adis_timeout *timeouts = adis->data->timeouts;
	struct gpio_desc *gpio;
	uint16_t prod_id;
	int ret;

	/* check if the device has rst pin low */
	gpio = devm_gpiod_get_optional(&adis->spi->dev, "reset", GPIOD_ASIS);
	if (IS_ERR(gpio))
		return PTR_ERR(gpio);

	if (gpio) {
		gpiod_set_value_cansleep(gpio, 1);
		msleep(10);
		/* bring device out of reset */
		gpiod_set_value_cansleep(gpio, 0);
		msleep(timeouts->reset_ms);
	} else {
		ret = __adis_reset(adis);
		if (ret)
			return ret;
	}

	ret = adis_self_test(adis);
	if (ret)
		return ret;

	if (!adis->data->prod_id_reg)
		return 0;

	ret = adis_read_reg_16(adis, adis->data->prod_id_reg, &prod_id);
	if (ret)
		return ret;

	if (prod_id != adis->data->prod_id)
		dev_warn(&adis->spi->dev,
			 "Device ID(%u) and product ID(%u) do not match.\n",
			 adis->data->prod_id, prod_id);

	return 0;
}
EXPORT_SYMBOL_GPL(__adis_initial_startup);

/**
 * adis_single_conversion() - Performs a single sample conversion
 * @indio_dev: The IIO device
 * @chan: The IIO channel
 * @error_mask: Mask for the error bit
 * @val: Result of the conversion
 *
 * Returns IIO_VAL_INT on success, a negative error code otherwise.
 *
 * The function performs a single conversion on a given channel and post
 * processes the value accordingly to the channel spec. If a error_mask is given
 * the function will check if the mask is set in the returned raw value. If it
 * is set the function will perform a self-check. If the device does not report
 * a error bit in the channels raw value set error_mask to 0.
 */
int adis_single_conversion(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan, unsigned int error_mask, int *val)
{
	struct adis *adis = iio_device_get_drvdata(indio_dev);
	unsigned int uval;
	int ret;

	mutex_lock(&adis->state_lock);

	ret = __adis_read_reg(adis, chan->address, &uval,
			chan->scan_type.storagebits / 8);
	if (ret)
		goto err_unlock;

	if (uval & error_mask) {
		ret = __adis_check_status(adis);
		if (ret)
			goto err_unlock;
	}

	if (chan->scan_type.sign == 's')
		*val = sign_extend32(uval, chan->scan_type.realbits - 1);
	else
		*val = uval & ((1 << chan->scan_type.realbits) - 1);

	ret = IIO_VAL_INT;
err_unlock:
	mutex_unlock(&adis->state_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(adis_single_conversion);

/**
 * adis_init() - Initialize adis device structure
 * @adis:	The adis device
 * @indio_dev:	The iio device
 * @spi:	The spi device
 * @data:	Chip specific data
 *
 * Returns 0 on success, a negative error code otherwise.
 *
 * This function must be called, before any other adis helper function may be
 * called.
 */
int adis_init(struct adis *adis, struct iio_dev *indio_dev,
	struct spi_device *spi, const struct adis_data *data)
{
	if (!data || !data->timeouts) {
		dev_err(&spi->dev, "No config data or timeouts not defined!\n");
		return -EINVAL;
	}

	mutex_init(&adis->state_lock);
	adis->spi = spi;
	adis->data = data;
	iio_device_set_drvdata(indio_dev, adis);

	if (data->has_paging) {
		/* Need to set the page before first read/write */
		adis->current_page = -1;
	} else {
		/* Page will always be 0 */
		adis->current_page = 0;
	}

	return adis_enable_irq(adis, false);
}
EXPORT_SYMBOL_GPL(adis_init);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Common library code for ADIS16XXX devices");