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 xfers[] = {
131 .rx_buf = &st->rx[0],
132 .tx_buf = &st->tx[0],
136 .rx_buf = &st->rx[1],
137 .tx_buf = &st->tx[1],
142 ad2s1210_set_mode(MOD_CONFIG, st);
143 st->tx[0] = address | AD2S1210_MSB_IS_HIGH;
144 st->tx[1] = AD2S1210_REG_FAULT;
145 ret = spi_sync_transfer(st->sdev, xfers, 2);
154 int ad2s1210_update_frequency_control_word(struct ad2s1210_state *st)
159 fcw = (unsigned char)(st->fexcit * (1 << 15) / st->fclkin);
160 if (fcw < AD2S1210_MIN_FCW || fcw > AD2S1210_MAX_FCW) {
161 dev_err(&st->sdev->dev, "ad2s1210: FCW out of range\n");
165 ret = ad2s1210_config_write(st, AD2S1210_REG_EXCIT_FREQ);
169 return ad2s1210_config_write(st, fcw);
172 static unsigned char ad2s1210_read_resolution_pin(struct ad2s1210_state *st)
174 return ad2s1210_resolution_value[
175 (gpio_get_value(st->pdata->res[0]) << 1) |
176 gpio_get_value(st->pdata->res[1])];
179 static const int ad2s1210_res_pins[4][2] = {
180 { 0, 0 }, {0, 1}, {1, 0}, {1, 1}
183 static inline void ad2s1210_set_resolution_pin(struct ad2s1210_state *st)
185 gpio_set_value(st->pdata->res[0],
186 ad2s1210_res_pins[(st->resolution - 10)/2][0]);
187 gpio_set_value(st->pdata->res[1],
188 ad2s1210_res_pins[(st->resolution - 10)/2][1]);
191 static inline int ad2s1210_soft_reset(struct ad2s1210_state *st)
195 ret = ad2s1210_config_write(st, AD2S1210_REG_SOFT_RESET);
199 return ad2s1210_config_write(st, 0x0);
202 static ssize_t ad2s1210_show_fclkin(struct device *dev,
203 struct device_attribute *attr,
206 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
208 return sprintf(buf, "%u\n", st->fclkin);
211 static ssize_t ad2s1210_store_fclkin(struct device *dev,
212 struct device_attribute *attr,
216 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
220 ret = kstrtouint(buf, 10, &fclkin);
223 if (fclkin < AD2S1210_MIN_CLKIN || fclkin > AD2S1210_MAX_CLKIN) {
224 dev_err(dev, "ad2s1210: fclkin out of range\n");
228 mutex_lock(&st->lock);
231 ret = ad2s1210_update_frequency_control_word(st);
234 ret = ad2s1210_soft_reset(st);
236 mutex_unlock(&st->lock);
238 return ret < 0 ? ret : len;
241 static ssize_t ad2s1210_show_fexcit(struct device *dev,
242 struct device_attribute *attr,
245 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
247 return sprintf(buf, "%u\n", st->fexcit);
250 static ssize_t ad2s1210_store_fexcit(struct device *dev,
251 struct device_attribute *attr,
252 const char *buf, size_t len)
254 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
258 ret = kstrtouint(buf, 10, &fexcit);
261 if (fexcit < AD2S1210_MIN_EXCIT || fexcit > AD2S1210_MAX_EXCIT) {
263 "ad2s1210: excitation frequency out of range\n");
266 mutex_lock(&st->lock);
268 ret = ad2s1210_update_frequency_control_word(st);
271 ret = ad2s1210_soft_reset(st);
273 mutex_unlock(&st->lock);
275 return ret < 0 ? ret : len;
278 static ssize_t ad2s1210_show_control(struct device *dev,
279 struct device_attribute *attr,
282 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
285 mutex_lock(&st->lock);
286 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
287 mutex_unlock(&st->lock);
288 return ret < 0 ? ret : sprintf(buf, "0x%x\n", ret);
291 static ssize_t ad2s1210_store_control(struct device *dev,
292 struct device_attribute *attr,
293 const char *buf, size_t len)
295 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
300 ret = kstrtou8(buf, 16, &udata);
304 mutex_lock(&st->lock);
305 ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
308 data = udata & AD2S1210_MSB_IS_LOW;
309 ret = ad2s1210_config_write(st, data);
313 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
316 if (ret & AD2S1210_MSB_IS_HIGH) {
319 "ad2s1210: write control register fail\n");
323 = ad2s1210_resolution_value[data & AD2S1210_SET_RESOLUTION];
324 if (st->pdata->gpioin) {
325 data = ad2s1210_read_resolution_pin(st);
326 if (data != st->resolution)
327 dev_warn(dev, "ad2s1210: resolution settings not match\n");
329 ad2s1210_set_resolution_pin(st);
332 st->hysteresis = !!(data & AD2S1210_ENABLE_HYSTERESIS);
335 mutex_unlock(&st->lock);
339 static ssize_t ad2s1210_show_resolution(struct device *dev,
340 struct device_attribute *attr, char *buf)
342 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
344 return sprintf(buf, "%d\n", st->resolution);
347 static ssize_t ad2s1210_store_resolution(struct device *dev,
348 struct device_attribute *attr,
349 const char *buf, size_t len)
351 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
356 ret = kstrtou8(buf, 10, &udata);
357 if (ret || udata < 10 || udata > 16) {
358 dev_err(dev, "ad2s1210: resolution out of range\n");
361 mutex_lock(&st->lock);
362 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
366 data &= ~AD2S1210_SET_RESOLUTION;
367 data |= (udata - 10) >> 1;
368 ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
371 ret = ad2s1210_config_write(st, data & AD2S1210_MSB_IS_LOW);
374 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
378 if (data & AD2S1210_MSB_IS_HIGH) {
380 dev_err(dev, "ad2s1210: setting resolution fail\n");
384 = ad2s1210_resolution_value[data & AD2S1210_SET_RESOLUTION];
385 if (st->pdata->gpioin) {
386 data = ad2s1210_read_resolution_pin(st);
387 if (data != st->resolution)
388 dev_warn(dev, "ad2s1210: resolution settings not match\n");
390 ad2s1210_set_resolution_pin(st);
393 mutex_unlock(&st->lock);
397 /* read the fault register since last sample */
398 static ssize_t ad2s1210_show_fault(struct device *dev,
399 struct device_attribute *attr, char *buf)
401 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
404 mutex_lock(&st->lock);
405 ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
406 mutex_unlock(&st->lock);
408 return ret ? ret : sprintf(buf, "0x%x\n", ret);
411 static ssize_t ad2s1210_clear_fault(struct device *dev,
412 struct device_attribute *attr,
416 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
419 mutex_lock(&st->lock);
420 gpio_set_value(st->pdata->sample, 0);
421 /* delay (2 * tck + 20) nano seconds */
423 gpio_set_value(st->pdata->sample, 1);
424 ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
427 gpio_set_value(st->pdata->sample, 0);
428 gpio_set_value(st->pdata->sample, 1);
430 mutex_unlock(&st->lock);
432 return ret < 0 ? ret : len;
435 static ssize_t ad2s1210_show_reg(struct device *dev,
436 struct device_attribute *attr,
439 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
440 struct iio_dev_attr *iattr = to_iio_dev_attr(attr);
443 mutex_lock(&st->lock);
444 ret = ad2s1210_config_read(st, iattr->address);
445 mutex_unlock(&st->lock);
447 return ret < 0 ? ret : sprintf(buf, "%d\n", ret);
450 static ssize_t ad2s1210_store_reg(struct device *dev,
451 struct device_attribute *attr, const char *buf, size_t len)
453 struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
456 struct iio_dev_attr *iattr = to_iio_dev_attr(attr);
458 ret = kstrtou8(buf, 10, &data);
461 mutex_lock(&st->lock);
462 ret = ad2s1210_config_write(st, iattr->address);
465 ret = ad2s1210_config_write(st, data & AD2S1210_MSB_IS_LOW);
467 mutex_unlock(&st->lock);
468 return ret < 0 ? ret : len;
471 static int ad2s1210_read_raw(struct iio_dev *indio_dev,
472 struct iio_chan_spec const *chan,
477 struct ad2s1210_state *st = iio_priv(indio_dev);
483 mutex_lock(&st->lock);
484 gpio_set_value(st->pdata->sample, 0);
485 /* delay (6 * tck + 20) nano seconds */
488 switch (chan->type) {
490 ad2s1210_set_mode(MOD_POS, st);
493 ad2s1210_set_mode(MOD_VEL, st);
501 ret = spi_read(st->sdev, st->rx, 2);
505 switch (chan->type) {
507 pos = be16_to_cpup((__be16 *) st->rx);
509 pos >>= 16 - st->resolution;
514 negative = st->rx[0] & 0x80;
515 vel = be16_to_cpup((__be16 *) st->rx);
516 vel >>= 16 - st->resolution;
518 negative = (0xffff >> st->resolution) << st->resolution;
525 mutex_unlock(&st->lock);
530 gpio_set_value(st->pdata->sample, 1);
531 /* delay (2 * tck + 20) nano seconds */
533 mutex_unlock(&st->lock);
537 static IIO_DEVICE_ATTR(fclkin, S_IRUGO | S_IWUSR,
538 ad2s1210_show_fclkin, ad2s1210_store_fclkin, 0);
539 static IIO_DEVICE_ATTR(fexcit, S_IRUGO | S_IWUSR,
540 ad2s1210_show_fexcit, ad2s1210_store_fexcit, 0);
541 static IIO_DEVICE_ATTR(control, S_IRUGO | S_IWUSR,
542 ad2s1210_show_control, ad2s1210_store_control, 0);
543 static IIO_DEVICE_ATTR(bits, S_IRUGO | S_IWUSR,
544 ad2s1210_show_resolution, ad2s1210_store_resolution, 0);
545 static IIO_DEVICE_ATTR(fault, S_IRUGO | S_IWUSR,
546 ad2s1210_show_fault, ad2s1210_clear_fault, 0);
548 static IIO_DEVICE_ATTR(los_thrd, S_IRUGO | S_IWUSR,
549 ad2s1210_show_reg, ad2s1210_store_reg,
550 AD2S1210_REG_LOS_THRD);
551 static IIO_DEVICE_ATTR(dos_ovr_thrd, S_IRUGO | S_IWUSR,
552 ad2s1210_show_reg, ad2s1210_store_reg,
553 AD2S1210_REG_DOS_OVR_THRD);
554 static IIO_DEVICE_ATTR(dos_mis_thrd, S_IRUGO | S_IWUSR,
555 ad2s1210_show_reg, ad2s1210_store_reg,
556 AD2S1210_REG_DOS_MIS_THRD);
557 static IIO_DEVICE_ATTR(dos_rst_max_thrd, S_IRUGO | S_IWUSR,
558 ad2s1210_show_reg, ad2s1210_store_reg,
559 AD2S1210_REG_DOS_RST_MAX_THRD);
560 static IIO_DEVICE_ATTR(dos_rst_min_thrd, S_IRUGO | S_IWUSR,
561 ad2s1210_show_reg, ad2s1210_store_reg,
562 AD2S1210_REG_DOS_RST_MIN_THRD);
563 static IIO_DEVICE_ATTR(lot_high_thrd, S_IRUGO | S_IWUSR,
564 ad2s1210_show_reg, ad2s1210_store_reg,
565 AD2S1210_REG_LOT_HIGH_THRD);
566 static IIO_DEVICE_ATTR(lot_low_thrd, S_IRUGO | S_IWUSR,
567 ad2s1210_show_reg, ad2s1210_store_reg,
568 AD2S1210_REG_LOT_LOW_THRD);
571 static const struct iio_chan_spec ad2s1210_channels[] = {
576 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
578 .type = IIO_ANGL_VEL,
581 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
585 static struct attribute *ad2s1210_attributes[] = {
586 &iio_dev_attr_fclkin.dev_attr.attr,
587 &iio_dev_attr_fexcit.dev_attr.attr,
588 &iio_dev_attr_control.dev_attr.attr,
589 &iio_dev_attr_bits.dev_attr.attr,
590 &iio_dev_attr_fault.dev_attr.attr,
591 &iio_dev_attr_los_thrd.dev_attr.attr,
592 &iio_dev_attr_dos_ovr_thrd.dev_attr.attr,
593 &iio_dev_attr_dos_mis_thrd.dev_attr.attr,
594 &iio_dev_attr_dos_rst_max_thrd.dev_attr.attr,
595 &iio_dev_attr_dos_rst_min_thrd.dev_attr.attr,
596 &iio_dev_attr_lot_high_thrd.dev_attr.attr,
597 &iio_dev_attr_lot_low_thrd.dev_attr.attr,
601 static const struct attribute_group ad2s1210_attribute_group = {
602 .attrs = ad2s1210_attributes,
605 static int ad2s1210_initial(struct ad2s1210_state *st)
610 mutex_lock(&st->lock);
611 if (st->pdata->gpioin)
612 st->resolution = ad2s1210_read_resolution_pin(st);
614 ad2s1210_set_resolution_pin(st);
616 ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
619 data = AD2S1210_DEF_CONTROL & ~(AD2S1210_SET_RESOLUTION);
620 data |= (st->resolution - 10) >> 1;
621 ret = ad2s1210_config_write(st, data);
624 ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
628 if (ret & AD2S1210_MSB_IS_HIGH) {
633 ret = ad2s1210_update_frequency_control_word(st);
636 ret = ad2s1210_soft_reset(st);
638 mutex_unlock(&st->lock);
642 static const struct iio_info ad2s1210_info = {
643 .read_raw = ad2s1210_read_raw,
644 .attrs = &ad2s1210_attribute_group,
645 .driver_module = THIS_MODULE,
648 static int ad2s1210_setup_gpios(struct ad2s1210_state *st)
650 unsigned long flags = st->pdata->gpioin ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
651 struct gpio ad2s1210_gpios[] = {
652 { st->pdata->sample, GPIOF_DIR_IN, "sample" },
653 { st->pdata->a[0], flags, "a0" },
654 { st->pdata->a[1], flags, "a1" },
655 { st->pdata->res[0], flags, "res0" },
656 { st->pdata->res[0], flags, "res1" },
659 return gpio_request_array(ad2s1210_gpios, ARRAY_SIZE(ad2s1210_gpios));
662 static void ad2s1210_free_gpios(struct ad2s1210_state *st)
664 unsigned long flags = st->pdata->gpioin ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
665 struct gpio ad2s1210_gpios[] = {
666 { st->pdata->sample, GPIOF_DIR_IN, "sample" },
667 { st->pdata->a[0], flags, "a0" },
668 { st->pdata->a[1], flags, "a1" },
669 { st->pdata->res[0], flags, "res0" },
670 { st->pdata->res[0], flags, "res1" },
673 gpio_free_array(ad2s1210_gpios, ARRAY_SIZE(ad2s1210_gpios));
676 static int ad2s1210_probe(struct spi_device *spi)
678 struct iio_dev *indio_dev;
679 struct ad2s1210_state *st;
682 if (spi->dev.platform_data == NULL)
685 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
688 st = iio_priv(indio_dev);
689 st->pdata = spi->dev.platform_data;
690 ret = ad2s1210_setup_gpios(st);
694 spi_set_drvdata(spi, indio_dev);
696 mutex_init(&st->lock);
698 st->hysteresis = true;
699 st->mode = MOD_CONFIG;
701 st->fexcit = AD2S1210_DEF_EXCIT;
703 indio_dev->dev.parent = &spi->dev;
704 indio_dev->info = &ad2s1210_info;
705 indio_dev->modes = INDIO_DIRECT_MODE;
706 indio_dev->channels = ad2s1210_channels;
707 indio_dev->num_channels = ARRAY_SIZE(ad2s1210_channels);
708 indio_dev->name = spi_get_device_id(spi)->name;
710 ret = iio_device_register(indio_dev);
712 goto error_free_gpios;
714 st->fclkin = spi->max_speed_hz;
715 spi->mode = SPI_MODE_3;
717 ad2s1210_initial(st);
722 ad2s1210_free_gpios(st);
726 static int ad2s1210_remove(struct spi_device *spi)
728 struct iio_dev *indio_dev = spi_get_drvdata(spi);
730 iio_device_unregister(indio_dev);
731 ad2s1210_free_gpios(iio_priv(indio_dev));
736 static const struct spi_device_id ad2s1210_id[] = {
740 MODULE_DEVICE_TABLE(spi, ad2s1210_id);
742 static struct spi_driver ad2s1210_driver = {
746 .probe = ad2s1210_probe,
747 .remove = ad2s1210_remove,
748 .id_table = ad2s1210_id,
750 module_spi_driver(ad2s1210_driver);
752 MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
753 MODULE_DESCRIPTION("Analog Devices AD2S1210 Resolver to Digital SPI driver");
754 MODULE_LICENSE("GPL v2");