1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Common library for ADIS16XXX devices
4  *
5  * Copyright 2012 Analog Devices Inc.
6  *   Author: Lars-Peter Clausen <lars@metafoo.de>
7  */
8 
9 #include <linux/delay.h>
10 #include <linux/gpio/consumer.h>
11 #include <linux/mutex.h>
12 #include <linux/device.h>
13 #include <linux/kernel.h>
14 #include <linux/spi/spi.h>
15 #include <linux/module.h>
16 #include <asm/unaligned.h>
17 
18 #include <linux/iio/iio.h>
19 #include <linux/iio/imu/adis.h>
20 
21 #define ADIS_MSC_CTRL_DATA_RDY_EN	BIT(2)
22 #define ADIS_MSC_CTRL_DATA_RDY_POL_HIGH	BIT(1)
23 #define ADIS_MSC_CTRL_DATA_RDY_DIO2	BIT(0)
24 #define ADIS_GLOB_CMD_SW_RESET		BIT(7)
25 
26 /**
27  * __adis_write_reg() - write N bytes to register (unlocked version)
28  * @adis: The adis device
29  * @reg: The address of the lower of the two registers
30  * @value: The value to write to device (up to 4 bytes)
31  * @size: The size of the @value (in bytes)
32  */
__adis_write_reg(struct adis * adis,unsigned int reg,unsigned int value,unsigned int size)33 int __adis_write_reg(struct adis *adis, unsigned int reg, unsigned int value,
34 		     unsigned int size)
35 {
36 	unsigned int page = reg / ADIS_PAGE_SIZE;
37 	int ret, i;
38 	struct spi_message msg;
39 	struct spi_transfer xfers[] = {
40 		{
41 			.tx_buf = adis->tx,
42 			.bits_per_word = 8,
43 			.len = 2,
44 			.cs_change = 1,
45 			.delay.value = adis->data->write_delay,
46 			.delay.unit = SPI_DELAY_UNIT_USECS,
47 			.cs_change_delay.value = adis->data->cs_change_delay,
48 			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
49 		}, {
50 			.tx_buf = adis->tx + 2,
51 			.bits_per_word = 8,
52 			.len = 2,
53 			.cs_change = 1,
54 			.delay.value = adis->data->write_delay,
55 			.delay.unit = SPI_DELAY_UNIT_USECS,
56 			.cs_change_delay.value = adis->data->cs_change_delay,
57 			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
58 		}, {
59 			.tx_buf = adis->tx + 4,
60 			.bits_per_word = 8,
61 			.len = 2,
62 			.cs_change = 1,
63 			.delay.value = adis->data->write_delay,
64 			.delay.unit = SPI_DELAY_UNIT_USECS,
65 			.cs_change_delay.value = adis->data->cs_change_delay,
66 			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
67 		}, {
68 			.tx_buf = adis->tx + 6,
69 			.bits_per_word = 8,
70 			.len = 2,
71 			.delay.value = adis->data->write_delay,
72 			.delay.unit = SPI_DELAY_UNIT_USECS,
73 		}, {
74 			.tx_buf = adis->tx + 8,
75 			.bits_per_word = 8,
76 			.len = 2,
77 			.delay.value = adis->data->write_delay,
78 			.delay.unit = SPI_DELAY_UNIT_USECS,
79 		},
80 	};
81 
82 	spi_message_init(&msg);
83 
84 	if (adis->current_page != page) {
85 		adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
86 		adis->tx[1] = page;
87 		spi_message_add_tail(&xfers[0], &msg);
88 	}
89 
90 	switch (size) {
91 	case 4:
92 		adis->tx[8] = ADIS_WRITE_REG(reg + 3);
93 		adis->tx[9] = (value >> 24) & 0xff;
94 		adis->tx[6] = ADIS_WRITE_REG(reg + 2);
95 		adis->tx[7] = (value >> 16) & 0xff;
96 		fallthrough;
97 	case 2:
98 		adis->tx[4] = ADIS_WRITE_REG(reg + 1);
99 		adis->tx[5] = (value >> 8) & 0xff;
100 		fallthrough;
101 	case 1:
102 		adis->tx[2] = ADIS_WRITE_REG(reg);
103 		adis->tx[3] = value & 0xff;
104 		break;
105 	default:
106 		return -EINVAL;
107 	}
108 
109 	xfers[size].cs_change = 0;
110 
111 	for (i = 1; i <= size; i++)
112 		spi_message_add_tail(&xfers[i], &msg);
113 
114 	ret = spi_sync(adis->spi, &msg);
115 	if (ret) {
116 		dev_err(&adis->spi->dev, "Failed to write register 0x%02X: %d\n",
117 			reg, ret);
118 	} else {
119 		adis->current_page = page;
120 	}
121 
122 	return ret;
123 }
124 EXPORT_SYMBOL_NS_GPL(__adis_write_reg, IIO_ADISLIB);
125 
126 /**
127  * __adis_read_reg() - read N bytes from register (unlocked version)
128  * @adis: The adis device
129  * @reg: The address of the lower of the two registers
130  * @val: The value read back from the device
131  * @size: The size of the @val buffer
132  */
__adis_read_reg(struct adis * adis,unsigned int reg,unsigned int * val,unsigned int size)133 int __adis_read_reg(struct adis *adis, unsigned int reg, unsigned int *val,
134 		    unsigned int size)
135 {
136 	unsigned int page = reg / ADIS_PAGE_SIZE;
137 	struct spi_message msg;
138 	int ret;
139 	struct spi_transfer xfers[] = {
140 		{
141 			.tx_buf = adis->tx,
142 			.bits_per_word = 8,
143 			.len = 2,
144 			.cs_change = 1,
145 			.delay.value = adis->data->write_delay,
146 			.delay.unit = SPI_DELAY_UNIT_USECS,
147 			.cs_change_delay.value = adis->data->cs_change_delay,
148 			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
149 		}, {
150 			.tx_buf = adis->tx + 2,
151 			.bits_per_word = 8,
152 			.len = 2,
153 			.cs_change = 1,
154 			.delay.value = adis->data->read_delay,
155 			.delay.unit = SPI_DELAY_UNIT_USECS,
156 			.cs_change_delay.value = adis->data->cs_change_delay,
157 			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
158 		}, {
159 			.tx_buf = adis->tx + 4,
160 			.rx_buf = adis->rx,
161 			.bits_per_word = 8,
162 			.len = 2,
163 			.cs_change = 1,
164 			.delay.value = adis->data->read_delay,
165 			.delay.unit = SPI_DELAY_UNIT_USECS,
166 			.cs_change_delay.value = adis->data->cs_change_delay,
167 			.cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
168 		}, {
169 			.rx_buf = adis->rx + 2,
170 			.bits_per_word = 8,
171 			.len = 2,
172 			.delay.value = adis->data->read_delay,
173 			.delay.unit = SPI_DELAY_UNIT_USECS,
174 		},
175 	};
176 
177 	spi_message_init(&msg);
178 
179 	if (adis->current_page != page) {
180 		adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
181 		adis->tx[1] = page;
182 		spi_message_add_tail(&xfers[0], &msg);
183 	}
184 
185 	switch (size) {
186 	case 4:
187 		adis->tx[2] = ADIS_READ_REG(reg + 2);
188 		adis->tx[3] = 0;
189 		spi_message_add_tail(&xfers[1], &msg);
190 		fallthrough;
191 	case 2:
192 		adis->tx[4] = ADIS_READ_REG(reg);
193 		adis->tx[5] = 0;
194 		spi_message_add_tail(&xfers[2], &msg);
195 		spi_message_add_tail(&xfers[3], &msg);
196 		break;
197 	default:
198 		return -EINVAL;
199 	}
200 
201 	ret = spi_sync(adis->spi, &msg);
202 	if (ret) {
203 		dev_err(&adis->spi->dev, "Failed to read register 0x%02X: %d\n",
204 			reg, ret);
205 		return ret;
206 	}
207 
208 	adis->current_page = page;
209 
210 	switch (size) {
211 	case 4:
212 		*val = get_unaligned_be32(adis->rx);
213 		break;
214 	case 2:
215 		*val = get_unaligned_be16(adis->rx + 2);
216 		break;
217 	}
218 
219 	return ret;
220 }
221 EXPORT_SYMBOL_NS_GPL(__adis_read_reg, IIO_ADISLIB);
222 /**
223  * __adis_update_bits_base() - ADIS Update bits function - Unlocked version
224  * @adis: The adis device
225  * @reg: The address of the lower of the two registers
226  * @mask: Bitmask to change
227  * @val: Value to be written
228  * @size: Size of the register to update
229  *
230  * Updates the desired bits of @reg in accordance with @mask and @val.
231  */
__adis_update_bits_base(struct adis * adis,unsigned int reg,const u32 mask,const u32 val,u8 size)232 int __adis_update_bits_base(struct adis *adis, unsigned int reg, const u32 mask,
233 			    const u32 val, u8 size)
234 {
235 	int ret;
236 	u32 __val;
237 
238 	ret = __adis_read_reg(adis, reg, &__val, size);
239 	if (ret)
240 		return ret;
241 
242 	__val = (__val & ~mask) | (val & mask);
243 
244 	return __adis_write_reg(adis, reg, __val, size);
245 }
246 EXPORT_SYMBOL_NS_GPL(__adis_update_bits_base, IIO_ADISLIB);
247 
248 #ifdef CONFIG_DEBUG_FS
249 
adis_debugfs_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)250 int adis_debugfs_reg_access(struct iio_dev *indio_dev, unsigned int reg,
251 			    unsigned int writeval, unsigned int *readval)
252 {
253 	struct adis *adis = iio_device_get_drvdata(indio_dev);
254 
255 	if (readval) {
256 		u16 val16;
257 		int ret;
258 
259 		ret = adis_read_reg_16(adis, reg, &val16);
260 		if (ret == 0)
261 			*readval = val16;
262 
263 		return ret;
264 	}
265 
266 	return adis_write_reg_16(adis, reg, writeval);
267 }
268 EXPORT_SYMBOL_NS(adis_debugfs_reg_access, IIO_ADISLIB);
269 
270 #endif
271 
272 /**
273  * __adis_enable_irq() - Enable or disable data ready IRQ (unlocked)
274  * @adis: The adis device
275  * @enable: Whether to enable the IRQ
276  *
277  * Returns 0 on success, negative error code otherwise
278  */
__adis_enable_irq(struct adis * adis,bool enable)279 int __adis_enable_irq(struct adis *adis, bool enable)
280 {
281 	int ret;
282 	u16 msc;
283 
284 	if (adis->data->enable_irq)
285 		return adis->data->enable_irq(adis, enable);
286 
287 	if (adis->data->unmasked_drdy) {
288 		if (enable)
289 			enable_irq(adis->spi->irq);
290 		else
291 			disable_irq(adis->spi->irq);
292 
293 		return 0;
294 	}
295 
296 	ret = __adis_read_reg_16(adis, adis->data->msc_ctrl_reg, &msc);
297 	if (ret)
298 		return ret;
299 
300 	msc |= ADIS_MSC_CTRL_DATA_RDY_POL_HIGH;
301 	msc &= ~ADIS_MSC_CTRL_DATA_RDY_DIO2;
302 	if (enable)
303 		msc |= ADIS_MSC_CTRL_DATA_RDY_EN;
304 	else
305 		msc &= ~ADIS_MSC_CTRL_DATA_RDY_EN;
306 
307 	return __adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc);
308 }
309 EXPORT_SYMBOL_NS(__adis_enable_irq, IIO_ADISLIB);
310 
311 /**
312  * __adis_check_status() - Check the device for error conditions (unlocked)
313  * @adis: The adis device
314  *
315  * Returns 0 on success, a negative error code otherwise
316  */
__adis_check_status(struct adis * adis)317 int __adis_check_status(struct adis *adis)
318 {
319 	u16 status;
320 	int ret;
321 	int i;
322 
323 	ret = __adis_read_reg_16(adis, adis->data->diag_stat_reg, &status);
324 	if (ret)
325 		return ret;
326 
327 	status &= adis->data->status_error_mask;
328 
329 	if (status == 0)
330 		return 0;
331 
332 	for (i = 0; i < 16; ++i) {
333 		if (status & BIT(i)) {
334 			dev_err(&adis->spi->dev, "%s.\n",
335 				adis->data->status_error_msgs[i]);
336 		}
337 	}
338 
339 	return -EIO;
340 }
341 EXPORT_SYMBOL_NS_GPL(__adis_check_status, IIO_ADISLIB);
342 
343 /**
344  * __adis_reset() - Reset the device (unlocked version)
345  * @adis: The adis device
346  *
347  * Returns 0 on success, a negative error code otherwise
348  */
__adis_reset(struct adis * adis)349 int __adis_reset(struct adis *adis)
350 {
351 	int ret;
352 	const struct adis_timeout *timeouts = adis->data->timeouts;
353 
354 	ret = __adis_write_reg_8(adis, adis->data->glob_cmd_reg,
355 				 ADIS_GLOB_CMD_SW_RESET);
356 	if (ret) {
357 		dev_err(&adis->spi->dev, "Failed to reset device: %d\n", ret);
358 		return ret;
359 	}
360 
361 	msleep(timeouts->sw_reset_ms);
362 
363 	return 0;
364 }
365 EXPORT_SYMBOL_NS_GPL(__adis_reset, IIO_ADIS_LIB);
366 
adis_self_test(struct adis * adis)367 static int adis_self_test(struct adis *adis)
368 {
369 	int ret;
370 	const struct adis_timeout *timeouts = adis->data->timeouts;
371 
372 	ret = __adis_write_reg_16(adis, adis->data->self_test_reg,
373 				  adis->data->self_test_mask);
374 	if (ret) {
375 		dev_err(&adis->spi->dev, "Failed to initiate self test: %d\n",
376 			ret);
377 		return ret;
378 	}
379 
380 	msleep(timeouts->self_test_ms);
381 
382 	ret = __adis_check_status(adis);
383 
384 	if (adis->data->self_test_no_autoclear)
385 		__adis_write_reg_16(adis, adis->data->self_test_reg, 0x00);
386 
387 	return ret;
388 }
389 
390 /**
391  * __adis_initial_startup() - Device initial setup
392  * @adis: The adis device
393  *
394  * The function performs a HW reset via a reset pin that should be specified
395  * via GPIOLIB. If no pin is configured a SW reset will be performed.
396  * The RST pin for the ADIS devices should be configured as ACTIVE_LOW.
397  *
398  * After the self-test operation is performed, the function will also check
399  * that the product ID is as expected. This assumes that drivers providing
400  * 'prod_id_reg' will also provide the 'prod_id'.
401  *
402  * Returns 0 if the device is operational, a negative error code otherwise.
403  *
404  * This function should be called early on in the device initialization sequence
405  * to ensure that the device is in a sane and known state and that it is usable.
406  */
__adis_initial_startup(struct adis * adis)407 int __adis_initial_startup(struct adis *adis)
408 {
409 	const struct adis_timeout *timeouts = adis->data->timeouts;
410 	struct gpio_desc *gpio;
411 	u16 prod_id;
412 	int ret;
413 
414 	/* check if the device has rst pin low */
415 	gpio = devm_gpiod_get_optional(&adis->spi->dev, "reset", GPIOD_OUT_HIGH);
416 	if (IS_ERR(gpio))
417 		return PTR_ERR(gpio);
418 
419 	if (gpio) {
420 		usleep_range(10, 12);
421 		/* bring device out of reset */
422 		gpiod_set_value_cansleep(gpio, 0);
423 		msleep(timeouts->reset_ms);
424 	} else {
425 		ret = __adis_reset(adis);
426 		if (ret)
427 			return ret;
428 	}
429 
430 	ret = adis_self_test(adis);
431 	if (ret)
432 		return ret;
433 
434 	/*
435 	 * don't bother calling this if we can't unmask the IRQ as in this case
436 	 * the IRQ is most likely not yet requested and we will request it
437 	 * with 'IRQF_NO_AUTOEN' anyways.
438 	 */
439 	if (!adis->data->unmasked_drdy)
440 		__adis_enable_irq(adis, false);
441 
442 	if (!adis->data->prod_id_reg)
443 		return 0;
444 
445 	ret = adis_read_reg_16(adis, adis->data->prod_id_reg, &prod_id);
446 	if (ret)
447 		return ret;
448 
449 	if (prod_id != adis->data->prod_id)
450 		dev_warn(&adis->spi->dev,
451 			 "Device ID(%u) and product ID(%u) do not match.\n",
452 			 adis->data->prod_id, prod_id);
453 
454 	return 0;
455 }
456 EXPORT_SYMBOL_NS_GPL(__adis_initial_startup, IIO_ADISLIB);
457 
458 /**
459  * adis_single_conversion() - Performs a single sample conversion
460  * @indio_dev: The IIO device
461  * @chan: The IIO channel
462  * @error_mask: Mask for the error bit
463  * @val: Result of the conversion
464  *
465  * Returns IIO_VAL_INT on success, a negative error code otherwise.
466  *
467  * The function performs a single conversion on a given channel and post
468  * processes the value accordingly to the channel spec. If a error_mask is given
469  * the function will check if the mask is set in the returned raw value. If it
470  * is set the function will perform a self-check. If the device does not report
471  * a error bit in the channels raw value set error_mask to 0.
472  */
adis_single_conversion(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int error_mask,int * val)473 int adis_single_conversion(struct iio_dev *indio_dev,
474 			   const struct iio_chan_spec *chan,
475 			   unsigned int error_mask, int *val)
476 {
477 	struct adis *adis = iio_device_get_drvdata(indio_dev);
478 	unsigned int uval;
479 	int ret;
480 
481 	mutex_lock(&adis->state_lock);
482 
483 	ret = __adis_read_reg(adis, chan->address, &uval,
484 			      chan->scan_type.storagebits / 8);
485 	if (ret)
486 		goto err_unlock;
487 
488 	if (uval & error_mask) {
489 		ret = __adis_check_status(adis);
490 		if (ret)
491 			goto err_unlock;
492 	}
493 
494 	if (chan->scan_type.sign == 's')
495 		*val = sign_extend32(uval, chan->scan_type.realbits - 1);
496 	else
497 		*val = uval & ((1 << chan->scan_type.realbits) - 1);
498 
499 	ret = IIO_VAL_INT;
500 err_unlock:
501 	mutex_unlock(&adis->state_lock);
502 	return ret;
503 }
504 EXPORT_SYMBOL_NS_GPL(adis_single_conversion, IIO_ADISLIB);
505 
506 /**
507  * adis_init() - Initialize adis device structure
508  * @adis:	The adis device
509  * @indio_dev:	The iio device
510  * @spi:	The spi device
511  * @data:	Chip specific data
512  *
513  * Returns 0 on success, a negative error code otherwise.
514  *
515  * This function must be called, before any other adis helper function may be
516  * called.
517  */
adis_init(struct adis * adis,struct iio_dev * indio_dev,struct spi_device * spi,const struct adis_data * data)518 int adis_init(struct adis *adis, struct iio_dev *indio_dev,
519 	      struct spi_device *spi, const struct adis_data *data)
520 {
521 	if (!data || !data->timeouts) {
522 		dev_err(&spi->dev, "No config data or timeouts not defined!\n");
523 		return -EINVAL;
524 	}
525 
526 	mutex_init(&adis->state_lock);
527 	adis->spi = spi;
528 	adis->data = data;
529 	iio_device_set_drvdata(indio_dev, adis);
530 
531 	if (data->has_paging) {
532 		/* Need to set the page before first read/write */
533 		adis->current_page = -1;
534 	} else {
535 		/* Page will always be 0 */
536 		adis->current_page = 0;
537 	}
538 
539 	return 0;
540 }
541 EXPORT_SYMBOL_NS_GPL(adis_init, IIO_ADISLIB);
542 
543 MODULE_LICENSE("GPL");
544 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
545 MODULE_DESCRIPTION("Common library code for ADIS16XXX devices");
546