1 /*
2 * Common library for ADIS16XXX devices
3 *
4 * Copyright 2012 Analog Devices Inc.
5 * Author: Lars-Peter Clausen <lars@metafoo.de>
6 *
7 * Licensed under the GPL-2 or later.
8 */
9
10 #include <linux/delay.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/slab.h>
16 #include <linux/sysfs.h>
17 #include <linux/module.h>
18 #include <asm/unaligned.h>
19
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 #include <linux/iio/buffer.h>
23 #include <linux/iio/imu/adis.h>
24
25 #define ADIS_MSC_CTRL_DATA_RDY_EN BIT(2)
26 #define ADIS_MSC_CTRL_DATA_RDY_POL_HIGH BIT(1)
27 #define ADIS_MSC_CTRL_DATA_RDY_DIO2 BIT(0)
28 #define ADIS_GLOB_CMD_SW_RESET BIT(7)
29
adis_write_reg(struct adis * adis,unsigned int reg,unsigned int value,unsigned int size)30 int adis_write_reg(struct adis *adis, unsigned int reg,
31 unsigned int value, unsigned int size)
32 {
33 unsigned int page = reg / ADIS_PAGE_SIZE;
34 int ret, i;
35 struct spi_message msg;
36 struct spi_transfer xfers[] = {
37 {
38 .tx_buf = adis->tx,
39 .bits_per_word = 8,
40 .len = 2,
41 .cs_change = 1,
42 .delay_usecs = adis->data->write_delay,
43 }, {
44 .tx_buf = adis->tx + 2,
45 .bits_per_word = 8,
46 .len = 2,
47 .cs_change = 1,
48 .delay_usecs = adis->data->write_delay,
49 }, {
50 .tx_buf = adis->tx + 4,
51 .bits_per_word = 8,
52 .len = 2,
53 .cs_change = 1,
54 .delay_usecs = adis->data->write_delay,
55 }, {
56 .tx_buf = adis->tx + 6,
57 .bits_per_word = 8,
58 .len = 2,
59 .delay_usecs = adis->data->write_delay,
60 }, {
61 .tx_buf = adis->tx + 8,
62 .bits_per_word = 8,
63 .len = 2,
64 .delay_usecs = adis->data->write_delay,
65 },
66 };
67
68 mutex_lock(&adis->txrx_lock);
69
70 spi_message_init(&msg);
71
72 if (adis->current_page != page) {
73 adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
74 adis->tx[1] = page;
75 spi_message_add_tail(&xfers[0], &msg);
76 }
77
78 switch (size) {
79 case 4:
80 adis->tx[8] = ADIS_WRITE_REG(reg + 3);
81 adis->tx[9] = (value >> 24) & 0xff;
82 adis->tx[6] = ADIS_WRITE_REG(reg + 2);
83 adis->tx[7] = (value >> 16) & 0xff;
84 case 2:
85 adis->tx[4] = ADIS_WRITE_REG(reg + 1);
86 adis->tx[5] = (value >> 8) & 0xff;
87 case 1:
88 adis->tx[2] = ADIS_WRITE_REG(reg);
89 adis->tx[3] = value & 0xff;
90 break;
91 default:
92 ret = -EINVAL;
93 goto out_unlock;
94 }
95
96 xfers[size].cs_change = 0;
97
98 for (i = 1; i <= size; i++)
99 spi_message_add_tail(&xfers[i], &msg);
100
101 ret = spi_sync(adis->spi, &msg);
102 if (ret) {
103 dev_err(&adis->spi->dev, "Failed to write register 0x%02X: %d\n",
104 reg, ret);
105 } else {
106 adis->current_page = page;
107 }
108
109 out_unlock:
110 mutex_unlock(&adis->txrx_lock);
111
112 return ret;
113 }
114 EXPORT_SYMBOL_GPL(adis_write_reg);
115
116 /**
117 * adis_read_reg() - read 2 bytes from a 16-bit register
118 * @adis: The adis device
119 * @reg: The address of the lower of the two registers
120 * @val: The value read back from the device
121 */
adis_read_reg(struct adis * adis,unsigned int reg,unsigned int * val,unsigned int size)122 int adis_read_reg(struct adis *adis, unsigned int reg,
123 unsigned int *val, unsigned int size)
124 {
125 unsigned int page = reg / ADIS_PAGE_SIZE;
126 struct spi_message msg;
127 int ret;
128 struct spi_transfer xfers[] = {
129 {
130 .tx_buf = adis->tx,
131 .bits_per_word = 8,
132 .len = 2,
133 .cs_change = 1,
134 .delay_usecs = adis->data->write_delay,
135 }, {
136 .tx_buf = adis->tx + 2,
137 .bits_per_word = 8,
138 .len = 2,
139 .cs_change = 1,
140 .delay_usecs = adis->data->read_delay,
141 }, {
142 .tx_buf = adis->tx + 4,
143 .rx_buf = adis->rx,
144 .bits_per_word = 8,
145 .len = 2,
146 .cs_change = 1,
147 .delay_usecs = adis->data->read_delay,
148 }, {
149 .rx_buf = adis->rx + 2,
150 .bits_per_word = 8,
151 .len = 2,
152 .delay_usecs = adis->data->read_delay,
153 },
154 };
155
156 mutex_lock(&adis->txrx_lock);
157 spi_message_init(&msg);
158
159 if (adis->current_page != page) {
160 adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
161 adis->tx[1] = page;
162 spi_message_add_tail(&xfers[0], &msg);
163 }
164
165 switch (size) {
166 case 4:
167 adis->tx[2] = ADIS_READ_REG(reg + 2);
168 adis->tx[3] = 0;
169 spi_message_add_tail(&xfers[1], &msg);
170 case 2:
171 adis->tx[4] = ADIS_READ_REG(reg);
172 adis->tx[5] = 0;
173 spi_message_add_tail(&xfers[2], &msg);
174 spi_message_add_tail(&xfers[3], &msg);
175 break;
176 default:
177 ret = -EINVAL;
178 goto out_unlock;
179 }
180
181 ret = spi_sync(adis->spi, &msg);
182 if (ret) {
183 dev_err(&adis->spi->dev, "Failed to read register 0x%02X: %d\n",
184 reg, ret);
185 goto out_unlock;
186 } else {
187 adis->current_page = page;
188 }
189
190 switch (size) {
191 case 4:
192 *val = get_unaligned_be32(adis->rx);
193 break;
194 case 2:
195 *val = get_unaligned_be16(adis->rx + 2);
196 break;
197 }
198
199 out_unlock:
200 mutex_unlock(&adis->txrx_lock);
201
202 return ret;
203 }
204 EXPORT_SYMBOL_GPL(adis_read_reg);
205
206 #ifdef CONFIG_DEBUG_FS
207
adis_debugfs_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)208 int adis_debugfs_reg_access(struct iio_dev *indio_dev,
209 unsigned int reg, unsigned int writeval, unsigned int *readval)
210 {
211 struct adis *adis = iio_device_get_drvdata(indio_dev);
212
213 if (readval) {
214 uint16_t val16;
215 int ret;
216
217 ret = adis_read_reg_16(adis, reg, &val16);
218 *readval = val16;
219
220 return ret;
221 } else {
222 return adis_write_reg_16(adis, reg, writeval);
223 }
224 }
225 EXPORT_SYMBOL(adis_debugfs_reg_access);
226
227 #endif
228
229 /**
230 * adis_enable_irq() - Enable or disable data ready IRQ
231 * @adis: The adis device
232 * @enable: Whether to enable the IRQ
233 *
234 * Returns 0 on success, negative error code otherwise
235 */
adis_enable_irq(struct adis * adis,bool enable)236 int adis_enable_irq(struct adis *adis, bool enable)
237 {
238 int ret = 0;
239 uint16_t msc;
240
241 if (adis->data->enable_irq)
242 return adis->data->enable_irq(adis, enable);
243
244 ret = adis_read_reg_16(adis, adis->data->msc_ctrl_reg, &msc);
245 if (ret)
246 goto error_ret;
247
248 msc |= ADIS_MSC_CTRL_DATA_RDY_POL_HIGH;
249 msc &= ~ADIS_MSC_CTRL_DATA_RDY_DIO2;
250 if (enable)
251 msc |= ADIS_MSC_CTRL_DATA_RDY_EN;
252 else
253 msc &= ~ADIS_MSC_CTRL_DATA_RDY_EN;
254
255 ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc);
256
257 error_ret:
258 return ret;
259 }
260 EXPORT_SYMBOL(adis_enable_irq);
261
262 /**
263 * adis_check_status() - Check the device for error conditions
264 * @adis: The adis device
265 *
266 * Returns 0 on success, a negative error code otherwise
267 */
adis_check_status(struct adis * adis)268 int adis_check_status(struct adis *adis)
269 {
270 uint16_t status;
271 int ret;
272 int i;
273
274 ret = adis_read_reg_16(adis, adis->data->diag_stat_reg, &status);
275 if (ret < 0)
276 return ret;
277
278 status &= adis->data->status_error_mask;
279
280 if (status == 0)
281 return 0;
282
283 for (i = 0; i < 16; ++i) {
284 if (status & BIT(i)) {
285 dev_err(&adis->spi->dev, "%s.\n",
286 adis->data->status_error_msgs[i]);
287 }
288 }
289
290 return -EIO;
291 }
292 EXPORT_SYMBOL_GPL(adis_check_status);
293
294 /**
295 * adis_reset() - Reset the device
296 * @adis: The adis device
297 *
298 * Returns 0 on success, a negative error code otherwise
299 */
adis_reset(struct adis * adis)300 int adis_reset(struct adis *adis)
301 {
302 int ret;
303
304 ret = adis_write_reg_8(adis, adis->data->glob_cmd_reg,
305 ADIS_GLOB_CMD_SW_RESET);
306 if (ret)
307 dev_err(&adis->spi->dev, "Failed to reset device: %d\n", ret);
308
309 return ret;
310 }
311 EXPORT_SYMBOL_GPL(adis_reset);
312
adis_self_test(struct adis * adis)313 static int adis_self_test(struct adis *adis)
314 {
315 int ret;
316
317 ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg,
318 adis->data->self_test_mask);
319 if (ret) {
320 dev_err(&adis->spi->dev, "Failed to initiate self test: %d\n",
321 ret);
322 return ret;
323 }
324
325 msleep(adis->data->startup_delay);
326
327 return adis_check_status(adis);
328 }
329
330 /**
331 * adis_inital_startup() - Performs device self-test
332 * @adis: The adis device
333 *
334 * Returns 0 if the device is operational, a negative error code otherwise.
335 *
336 * This function should be called early on in the device initialization sequence
337 * to ensure that the device is in a sane and known state and that it is usable.
338 */
adis_initial_startup(struct adis * adis)339 int adis_initial_startup(struct adis *adis)
340 {
341 int ret;
342
343 ret = adis_self_test(adis);
344 if (ret) {
345 dev_err(&adis->spi->dev, "Self-test failed, trying reset.\n");
346 adis_reset(adis);
347 msleep(adis->data->startup_delay);
348 ret = adis_self_test(adis);
349 if (ret) {
350 dev_err(&adis->spi->dev, "Second self-test failed, giving up.\n");
351 return ret;
352 }
353 }
354
355 return 0;
356 }
357 EXPORT_SYMBOL_GPL(adis_initial_startup);
358
359 /**
360 * adis_single_conversion() - Performs a single sample conversion
361 * @indio_dev: The IIO device
362 * @chan: The IIO channel
363 * @error_mask: Mask for the error bit
364 * @val: Result of the conversion
365 *
366 * Returns IIO_VAL_INT on success, a negative error code otherwise.
367 *
368 * The function performs a single conversion on a given channel and post
369 * processes the value accordingly to the channel spec. If a error_mask is given
370 * the function will check if the mask is set in the returned raw value. If it
371 * is set the function will perform a self-check. If the device does not report
372 * a error bit in the channels raw value set error_mask to 0.
373 */
adis_single_conversion(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int error_mask,int * val)374 int adis_single_conversion(struct iio_dev *indio_dev,
375 const struct iio_chan_spec *chan, unsigned int error_mask, int *val)
376 {
377 struct adis *adis = iio_device_get_drvdata(indio_dev);
378 unsigned int uval;
379 int ret;
380
381 mutex_lock(&indio_dev->mlock);
382
383 ret = adis_read_reg(adis, chan->address, &uval,
384 chan->scan_type.storagebits / 8);
385 if (ret)
386 goto err_unlock;
387
388 if (uval & error_mask) {
389 ret = adis_check_status(adis);
390 if (ret)
391 goto err_unlock;
392 }
393
394 if (chan->scan_type.sign == 's')
395 *val = sign_extend32(uval, chan->scan_type.realbits - 1);
396 else
397 *val = uval & ((1 << chan->scan_type.realbits) - 1);
398
399 ret = IIO_VAL_INT;
400 err_unlock:
401 mutex_unlock(&indio_dev->mlock);
402 return ret;
403 }
404 EXPORT_SYMBOL_GPL(adis_single_conversion);
405
406 /**
407 * adis_init() - Initialize adis device structure
408 * @adis: The adis device
409 * @indio_dev: The iio device
410 * @spi: The spi device
411 * @data: Chip specific data
412 *
413 * Returns 0 on success, a negative error code otherwise.
414 *
415 * This function must be called, before any other adis helper function may be
416 * called.
417 */
adis_init(struct adis * adis,struct iio_dev * indio_dev,struct spi_device * spi,const struct adis_data * data)418 int adis_init(struct adis *adis, struct iio_dev *indio_dev,
419 struct spi_device *spi, const struct adis_data *data)
420 {
421 mutex_init(&adis->txrx_lock);
422 adis->spi = spi;
423 adis->data = data;
424 iio_device_set_drvdata(indio_dev, adis);
425
426 if (data->has_paging) {
427 /* Need to set the page before first read/write */
428 adis->current_page = -1;
429 } else {
430 /* Page will always be 0 */
431 adis->current_page = 0;
432 }
433
434 return adis_enable_irq(adis, false);
435 }
436 EXPORT_SYMBOL_GPL(adis_init);
437
438 MODULE_LICENSE("GPL");
439 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
440 MODULE_DESCRIPTION("Common library code for ADIS16XXX devices");
441