2 * ad2s1210.c support for the ADI Resolver to Digital Converters: AD2S1210
4 * Copyright (c) 2010-2010 Analog Devices Inc.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
11 #include <linux/types.h>
12 #include <linux/mutex.h>
13 #include <linux/device.h>
14 #include <linux/spi/spi.h>
15 #include <linux/slab.h>
16 #include <linux/sysfs.h>
17 #include <linux/delay.h>
18 #include <linux/gpio.h>
19 #include <linux/module.h>
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
25 #define DRV_NAME "ad2s1210"
27 #define AD2S1210_DEF_CONTROL 0x7E
29 #define AD2S1210_MSB_IS_HIGH 0x80
30 #define AD2S1210_MSB_IS_LOW 0x7F
31 #define AD2S1210_PHASE_LOCK_RANGE_44 0x20
32 #define AD2S1210_ENABLE_HYSTERESIS 0x10
33 #define AD2S1210_SET_ENRES1 0x08
34 #define AD2S1210_SET_ENRES0 0x04
35 #define AD2S1210_SET_RES1 0x02
36 #define AD2S1210_SET_RES0 0x01
38 #define AD2S1210_SET_ENRESOLUTION (AD2S1210_SET_ENRES1 | \
40 #define AD2S1210_SET_RESOLUTION (AD2S1210_SET_RES1 | AD2S1210_SET_RES0)
42 #define AD2S1210_REG_POSITION 0x80
43 #define AD2S1210_REG_VELOCITY 0x82
44 #define AD2S1210_REG_LOS_THRD 0x88
45 #define AD2S1210_REG_DOS_OVR_THRD 0x89
46 #define AD2S1210_REG_DOS_MIS_THRD 0x8A
47 #define AD2S1210_REG_DOS_RST_MAX_THRD 0x8B
48 #define AD2S1210_REG_DOS_RST_MIN_THRD 0x8C
49 #define AD2S1210_REG_LOT_HIGH_THRD 0x8D
50 #define AD2S1210_REG_LOT_LOW_THRD 0x8E
51 #define AD2S1210_REG_EXCIT_FREQ 0x91
52 #define AD2S1210_REG_CONTROL 0x92
53 #define AD2S1210_REG_SOFT_RESET 0xF0
54 #define AD2S1210_REG_FAULT 0xFF
56 /* pin SAMPLE, A0, A1, RES0, RES1, is controlled by driver */
57 #define AD2S1210_SAA 3
58 #define AD2S1210_PN (AD2S1210_SAA + AD2S1210_RES)
60 #define AD2S1210_MIN_CLKIN 6144000
61 #define AD2S1210_MAX_CLKIN 10240000
62 #define AD2S1210_MIN_EXCIT 2000
63 #define AD2S1210_MAX_EXCIT 20000
64 #define AD2S1210_MIN_FCW 0x4
65 #define AD2S1210_MAX_FCW 0x50
67 /* default input clock on serial interface */
68 #define AD2S1210_DEF_CLKIN 8192000
69 /* clock period in nano second */
70 #define AD2S1210_DEF_TCK (1000000000/AD2S1210_DEF_CLKIN)
71 #define AD2S1210_DEF_EXCIT 10000
80 static const unsigned int ad2s1210_resolution_value[] = { 10, 12, 14, 16 };
82 struct ad2s1210_state {
83 const struct ad2s1210_platform_data *pdata;
85 struct spi_device *sdev;
91 enum ad2s1210_mode mode;
92 u8 rx[2] ____cacheline_aligned;
93 u8 tx[2] ____cacheline_aligned;
96 static const int ad2s1210_mode_vals[4][2] = {
99 [MOD_CONFIG] = { 1, 0 },
101 static inline void ad2s1210_set_mode(enum ad2s1210_mode mode,
102 struct ad2s1210_state *st)
104 gpio_set_value(st->pdata->a[0], ad2s1210_mode_vals[mode][0]);
105 gpio_set_value(st->pdata->a[1], ad2s1210_mode_vals[mode][1]);
109 /* write 1 bytes (address or data) to the chip */
110 static int ad2s1210_config_write(struct ad2s1210_state *st, u8 data)
114 ad2s1210_set_mode(MOD_CONFIG, st);
116 ret = spi_write(st->sdev, st->tx, 1);
124 /* read value from one of the registers */
125 static int ad2s1210_config_read(struct ad2s1210_state *st,
126 unsigned char address)
128 struct spi_transfer xfer = {
135 ad2s1210_set_mode(MOD_CONFIG, st);
136 st->tx[0] = address | AD2S1210_MSB_IS_HIGH;
137 st->tx[1] = AD2S1210_REG_FAULT;
138 ret = spi_sync_transfer(st->sdev, &xfer, 1);
147 int ad2s1210_update_frequency_control_word(struct ad2s1210_state *st)
152 fcw = (unsigned char)(st->fexcit * (1 << 15) / st->fclkin);
153 if (fcw < AD2S1210_MIN_FCW || fcw > AD2S1210_MAX_FCW) {
154 dev_err(&st->sdev->dev, "ad2s1210: FCW out of range\n");
158 ret = ad2s1210_config_write(st, AD2S1210_REG_EXCIT_FREQ);
162 return ad2s1210_config_write(st, fcw);
165 static unsigned char ad2s1210_read_resolution_pin(struct ad2s1210_state *st)
167 return ad2s1210_resolution_value[
168 (gpio_get_value(st->pdata->res[0]) << 1) |
169 gpio_get_value(st->pdata->res[1])];
172 static const int ad2s1210_res_pins[4][2] = {
173 { 0, 0 }, {0, 1}, {1, 0}, {1, 1}
176 static inline void ad2s1210_set_resolution_pin(struct ad2s1210_state *st)
178 gpio_set_value(st->pdata->res[0],
179 ad2s1210_res_pins[(st->resolution - 10)/2][0]);
180 gpio_set_value(st->pdata->res[1],
181 ad2s1210_res_pins[(st->resolution - 10)/2][1]);
184 static inline int ad2s1210_soft_reset(struct ad2s1210_state *st)
188 ret = ad2s1210_config_write(st, AD2S1210_REG_SOFT_RESET);
192 return ad2s1210_config_write(st, 0x0);
195 static ssize_t ad2s1210_show_fclkin(struct device *dev,
196 struct device_attribute *attr,
199 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
201 return sprintf(buf, "%u\n", st->fclkin);
204 static ssize_t ad2s1210_store_fclkin(struct device *dev,
205 struct device_attribute *attr,
209 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
213 ret = kstrtouint(buf, 10, &fclkin);
216 if (fclkin < AD2S1210_MIN_CLKIN || fclkin > AD2S1210_MAX_CLKIN) {
217 dev_err(dev, "ad2s1210: fclkin out of range\n");
221 mutex_lock(&st->lock);
224 ret = ad2s1210_update_frequency_control_word(st);
227 ret = ad2s1210_soft_reset(st);
229 mutex_unlock(&st->lock);
231 return ret < 0 ? ret : len;
234 static ssize_t ad2s1210_show_fexcit(struct device *dev,
235 struct device_attribute *attr,
238 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
240 return sprintf(buf, "%u\n", st->fexcit);
243 static ssize_t ad2s1210_store_fexcit(struct device *dev,
244 struct device_attribute *attr,
245 const char *buf, size_t len)
247 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
251 ret = kstrtouint(buf, 10, &fexcit);
254 if (fexcit < AD2S1210_MIN_EXCIT || fexcit > AD2S1210_MAX_EXCIT) {
256 "ad2s1210: excitation frequency out of range\n");
259 mutex_lock(&st->lock);
261 ret = ad2s1210_update_frequency_control_word(st);
264 ret = ad2s1210_soft_reset(st);
266 mutex_unlock(&st->lock);
268 return ret < 0 ? ret : len;
271 static ssize_t ad2s1210_show_control(struct device *dev,
272 struct device_attribute *attr,
275 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
278 mutex_lock(&st->lock);
279 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
280 mutex_unlock(&st->lock);
281 return ret < 0 ? ret : sprintf(buf, "0x%x\n", ret);
284 static ssize_t ad2s1210_store_control(struct device *dev,
285 struct device_attribute *attr,
286 const char *buf, size_t len)
288 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
293 ret = kstrtou8(buf, 16, &udata);
297 mutex_lock(&st->lock);
298 ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
301 data = udata & AD2S1210_MSB_IS_LOW;
302 ret = ad2s1210_config_write(st, data);
306 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
309 if (ret & AD2S1210_MSB_IS_HIGH) {
312 "ad2s1210: write control register fail\n");
316 = ad2s1210_resolution_value[data & AD2S1210_SET_RESOLUTION];
317 if (st->pdata->gpioin) {
318 data = ad2s1210_read_resolution_pin(st);
319 if (data != st->resolution)
320 dev_warn(dev, "ad2s1210: resolution settings not match\n");
322 ad2s1210_set_resolution_pin(st);
325 st->hysteresis = !!(data & AD2S1210_ENABLE_HYSTERESIS);
328 mutex_unlock(&st->lock);
332 static ssize_t ad2s1210_show_resolution(struct device *dev,
333 struct device_attribute *attr, char *buf)
335 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
337 return sprintf(buf, "%d\n", st->resolution);
340 static ssize_t ad2s1210_store_resolution(struct device *dev,
341 struct device_attribute *attr,
342 const char *buf, size_t len)
344 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
349 ret = kstrtou8(buf, 10, &udata);
350 if (ret || udata < 10 || udata > 16) {
351 dev_err(dev, "ad2s1210: resolution out of range\n");
354 mutex_lock(&st->lock);
355 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
359 data &= ~AD2S1210_SET_RESOLUTION;
360 data |= (udata - 10) >> 1;
361 ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
364 ret = ad2s1210_config_write(st, data & AD2S1210_MSB_IS_LOW);
367 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
371 if (data & AD2S1210_MSB_IS_HIGH) {
373 dev_err(dev, "ad2s1210: setting resolution fail\n");
377 = ad2s1210_resolution_value[data & AD2S1210_SET_RESOLUTION];
378 if (st->pdata->gpioin) {
379 data = ad2s1210_read_resolution_pin(st);
380 if (data != st->resolution)
381 dev_warn(dev, "ad2s1210: resolution settings not match\n");
383 ad2s1210_set_resolution_pin(st);
386 mutex_unlock(&st->lock);
390 /* read the fault register since last sample */
391 static ssize_t ad2s1210_show_fault(struct device *dev,
392 struct device_attribute *attr, char *buf)
394 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
397 mutex_lock(&st->lock);
398 ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
399 mutex_unlock(&st->lock);
401 return ret ? ret : sprintf(buf, "0x%x\n", ret);
404 static ssize_t ad2s1210_clear_fault(struct device *dev,
405 struct device_attribute *attr,
409 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
412 mutex_lock(&st->lock);
413 gpio_set_value(st->pdata->sample, 0);
414 /* delay (2 * tck + 20) nano seconds */
416 gpio_set_value(st->pdata->sample, 1);
417 ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
420 gpio_set_value(st->pdata->sample, 0);
421 gpio_set_value(st->pdata->sample, 1);
423 mutex_unlock(&st->lock);
425 return ret < 0 ? ret : len;
428 static ssize_t ad2s1210_show_reg(struct device *dev,
429 struct device_attribute *attr,
432 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
433 struct iio_dev_attr *iattr = to_iio_dev_attr(attr);
436 mutex_lock(&st->lock);
437 ret = ad2s1210_config_read(st, iattr->address);
438 mutex_unlock(&st->lock);
440 return ret < 0 ? ret : sprintf(buf, "%d\n", ret);
443 static ssize_t ad2s1210_store_reg(struct device *dev,
444 struct device_attribute *attr, const char *buf, size_t len)
446 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
449 struct iio_dev_attr *iattr = to_iio_dev_attr(attr);
451 ret = kstrtou8(buf, 10, &data);
454 mutex_lock(&st->lock);
455 ret = ad2s1210_config_write(st, iattr->address);
458 ret = ad2s1210_config_write(st, data & AD2S1210_MSB_IS_LOW);
460 mutex_unlock(&st->lock);
461 return ret < 0 ? ret : len;
464 static int ad2s1210_read_raw(struct iio_dev *indio_dev,
465 struct iio_chan_spec const *chan,
470 struct ad2s1210_state *st = iio_priv(indio_dev);
476 mutex_lock(&st->lock);
477 gpio_set_value(st->pdata->sample, 0);
478 /* delay (6 * tck + 20) nano seconds */
481 switch (chan->type) {
483 ad2s1210_set_mode(MOD_POS, st);
486 ad2s1210_set_mode(MOD_VEL, st);
494 ret = spi_read(st->sdev, st->rx, 2);
498 switch (chan->type) {
500 pos = be16_to_cpup((__be16 *) st->rx);
502 pos >>= 16 - st->resolution;
507 negative = st->rx[0] & 0x80;
508 vel = be16_to_cpup((__be16 *) st->rx);
509 vel >>= 16 - st->resolution;
511 negative = (0xffff >> st->resolution) << st->resolution;
518 mutex_unlock(&st->lock);
523 gpio_set_value(st->pdata->sample, 1);
524 /* delay (2 * tck + 20) nano seconds */
526 mutex_unlock(&st->lock);
530 static IIO_DEVICE_ATTR(fclkin, S_IRUGO | S_IWUSR,
531 ad2s1210_show_fclkin, ad2s1210_store_fclkin, 0);
532 static IIO_DEVICE_ATTR(fexcit, S_IRUGO | S_IWUSR,
533 ad2s1210_show_fexcit, ad2s1210_store_fexcit, 0);
534 static IIO_DEVICE_ATTR(control, S_IRUGO | S_IWUSR,
535 ad2s1210_show_control, ad2s1210_store_control, 0);
536 static IIO_DEVICE_ATTR(bits, S_IRUGO | S_IWUSR,
537 ad2s1210_show_resolution, ad2s1210_store_resolution, 0);
538 static IIO_DEVICE_ATTR(fault, S_IRUGO | S_IWUSR,
539 ad2s1210_show_fault, ad2s1210_clear_fault, 0);
541 static IIO_DEVICE_ATTR(los_thrd, S_IRUGO | S_IWUSR,
542 ad2s1210_show_reg, ad2s1210_store_reg,
543 AD2S1210_REG_LOS_THRD);
544 static IIO_DEVICE_ATTR(dos_ovr_thrd, S_IRUGO | S_IWUSR,
545 ad2s1210_show_reg, ad2s1210_store_reg,
546 AD2S1210_REG_DOS_OVR_THRD);
547 static IIO_DEVICE_ATTR(dos_mis_thrd, S_IRUGO | S_IWUSR,
548 ad2s1210_show_reg, ad2s1210_store_reg,
549 AD2S1210_REG_DOS_MIS_THRD);
550 static IIO_DEVICE_ATTR(dos_rst_max_thrd, S_IRUGO | S_IWUSR,
551 ad2s1210_show_reg, ad2s1210_store_reg,
552 AD2S1210_REG_DOS_RST_MAX_THRD);
553 static IIO_DEVICE_ATTR(dos_rst_min_thrd, S_IRUGO | S_IWUSR,
554 ad2s1210_show_reg, ad2s1210_store_reg,
555 AD2S1210_REG_DOS_RST_MIN_THRD);
556 static IIO_DEVICE_ATTR(lot_high_thrd, S_IRUGO | S_IWUSR,
557 ad2s1210_show_reg, ad2s1210_store_reg,
558 AD2S1210_REG_LOT_HIGH_THRD);
559 static IIO_DEVICE_ATTR(lot_low_thrd, S_IRUGO | S_IWUSR,
560 ad2s1210_show_reg, ad2s1210_store_reg,
561 AD2S1210_REG_LOT_LOW_THRD);
564 static const struct iio_chan_spec ad2s1210_channels[] = {
569 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
571 .type = IIO_ANGL_VEL,
574 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
578 static struct attribute *ad2s1210_attributes[] = {
579 &iio_dev_attr_fclkin.dev_attr.attr,
580 &iio_dev_attr_fexcit.dev_attr.attr,
581 &iio_dev_attr_control.dev_attr.attr,
582 &iio_dev_attr_bits.dev_attr.attr,
583 &iio_dev_attr_fault.dev_attr.attr,
584 &iio_dev_attr_los_thrd.dev_attr.attr,
585 &iio_dev_attr_dos_ovr_thrd.dev_attr.attr,
586 &iio_dev_attr_dos_mis_thrd.dev_attr.attr,
587 &iio_dev_attr_dos_rst_max_thrd.dev_attr.attr,
588 &iio_dev_attr_dos_rst_min_thrd.dev_attr.attr,
589 &iio_dev_attr_lot_high_thrd.dev_attr.attr,
590 &iio_dev_attr_lot_low_thrd.dev_attr.attr,
594 static const struct attribute_group ad2s1210_attribute_group = {
595 .attrs = ad2s1210_attributes,
598 static int ad2s1210_initial(struct ad2s1210_state *st)
603 mutex_lock(&st->lock);
604 if (st->pdata->gpioin)
605 st->resolution = ad2s1210_read_resolution_pin(st);
607 ad2s1210_set_resolution_pin(st);
609 ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
612 data = AD2S1210_DEF_CONTROL & ~(AD2S1210_SET_RESOLUTION);
613 data |= (st->resolution - 10) >> 1;
614 ret = ad2s1210_config_write(st, data);
617 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
621 if (ret & AD2S1210_MSB_IS_HIGH) {
626 ret = ad2s1210_update_frequency_control_word(st);
629 ret = ad2s1210_soft_reset(st);
631 mutex_unlock(&st->lock);
635 static const struct iio_info ad2s1210_info = {
636 .read_raw = ad2s1210_read_raw,
637 .attrs = &ad2s1210_attribute_group,
638 .driver_module = THIS_MODULE,
641 static int ad2s1210_setup_gpios(struct ad2s1210_state *st)
643 unsigned long flags = st->pdata->gpioin ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
644 struct gpio ad2s1210_gpios[] = {
645 { st->pdata->sample, GPIOF_DIR_IN, "sample" },
646 { st->pdata->a[0], flags, "a0" },
647 { st->pdata->a[1], flags, "a1" },
648 { st->pdata->res[0], flags, "res0" },
649 { st->pdata->res[0], flags, "res1" },
652 return gpio_request_array(ad2s1210_gpios, ARRAY_SIZE(ad2s1210_gpios));
655 static void ad2s1210_free_gpios(struct ad2s1210_state *st)
657 unsigned long flags = st->pdata->gpioin ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
658 struct gpio ad2s1210_gpios[] = {
659 { st->pdata->sample, GPIOF_DIR_IN, "sample" },
660 { st->pdata->a[0], flags, "a0" },
661 { st->pdata->a[1], flags, "a1" },
662 { st->pdata->res[0], flags, "res0" },
663 { st->pdata->res[0], flags, "res1" },
666 gpio_free_array(ad2s1210_gpios, ARRAY_SIZE(ad2s1210_gpios));
669 static int ad2s1210_probe(struct spi_device *spi)
671 struct iio_dev *indio_dev;
672 struct ad2s1210_state *st;
675 if (spi->dev.platform_data == NULL)
678 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
681 st = iio_priv(indio_dev);
682 st->pdata = spi->dev.platform_data;
683 ret = ad2s1210_setup_gpios(st);
687 spi_set_drvdata(spi, indio_dev);
689 mutex_init(&st->lock);
691 st->hysteresis = true;
692 st->mode = MOD_CONFIG;
694 st->fexcit = AD2S1210_DEF_EXCIT;
696 indio_dev->dev.parent = &spi->dev;
697 indio_dev->info = &ad2s1210_info;
698 indio_dev->modes = INDIO_DIRECT_MODE;
699 indio_dev->channels = ad2s1210_channels;
700 indio_dev->num_channels = ARRAY_SIZE(ad2s1210_channels);
701 indio_dev->name = spi_get_device_id(spi)->name;
703 ret = iio_device_register(indio_dev);
705 goto error_free_gpios;
707 st->fclkin = spi->max_speed_hz;
708 spi->mode = SPI_MODE_3;
710 ad2s1210_initial(st);
715 ad2s1210_free_gpios(st);
719 static int ad2s1210_remove(struct spi_device *spi)
721 struct iio_dev *indio_dev = spi_get_drvdata(spi);
723 iio_device_unregister(indio_dev);
724 ad2s1210_free_gpios(iio_priv(indio_dev));
729 static const struct spi_device_id ad2s1210_id[] = {
733 MODULE_DEVICE_TABLE(spi, ad2s1210_id);
735 static struct spi_driver ad2s1210_driver = {
738 .owner = THIS_MODULE,
740 .probe = ad2s1210_probe,
741 .remove = ad2s1210_remove,
742 .id_table = ad2s1210_id,
744 module_spi_driver(ad2s1210_driver);
746 MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
747 MODULE_DESCRIPTION("Analog Devices AD2S1210 Resolver to Digital SPI driver");
748 MODULE_LICENSE("GPL v2");