1 // SPDX-License-Identifier: GPL-2.0-only
3  * Support code for Analog Devices Sigma-Delta ADCs
6  *  Author: Lars-Peter Clausen <[email protected]>
38  * ad_sd_set_comm() - Set communications register
40  * @sigma_delta: The sigma delta device
47 	sigma_delta->comm = comm & AD_SD_COMM_CHAN_MASK;  in ad_sd_set_comm()
52  * ad_sd_write_reg() - Write a register
54  * @sigma_delta: The sigma delta device
56  * @size: Size of the register (0-3)
64 	uint8_t *data = sigma_delta->tx_buf;  in ad_sd_write_reg()
68 		.cs_change	= sigma_delta->keep_cs_asserted,  in ad_sd_write_reg()
73 	data[0] = (reg << sigma_delta->info->addr_shift) | sigma_delta->comm;  in ad_sd_write_reg()
88 		return -EINVAL;  in ad_sd_write_reg()
94 	if (sigma_delta->bus_locked)  in ad_sd_write_reg()
95 		ret = spi_sync_locked(sigma_delta->spi, &m);  in ad_sd_write_reg()
97 		ret = spi_sync(sigma_delta->spi, &m);  in ad_sd_write_reg()
106 	uint8_t *data = sigma_delta->tx_buf;  in ad_sd_read_reg_raw()
115 			.cs_change = sigma_delta->keep_cs_asserted,  in ad_sd_read_reg_raw()
122 	if (sigma_delta->info->has_registers) {  in ad_sd_read_reg_raw()
123 		data[0] = reg << sigma_delta->info->addr_shift;  in ad_sd_read_reg_raw()
124 		data[0] |= sigma_delta->info->read_mask;  in ad_sd_read_reg_raw()
125 		data[0] |= sigma_delta->comm;  in ad_sd_read_reg_raw()
130 	if (sigma_delta->bus_locked)  in ad_sd_read_reg_raw()
131 		ret = spi_sync_locked(sigma_delta->spi, &m);  in ad_sd_read_reg_raw()
133 		ret = spi_sync(sigma_delta->spi, &m);  in ad_sd_read_reg_raw()
139  * ad_sd_read_reg() - Read a register
141  * @sigma_delta: The sigma delta device
143  * @size: Size of the register (1-4)
153 	ret = ad_sd_read_reg_raw(sigma_delta, reg, size, sigma_delta->rx_buf);  in ad_sd_read_reg()
159 		*val = get_unaligned_be32(sigma_delta->rx_buf);  in ad_sd_read_reg()
162 		*val = get_unaligned_be24(sigma_delta->rx_buf);  in ad_sd_read_reg()
165 		*val = get_unaligned_be16(sigma_delta->rx_buf);  in ad_sd_read_reg()
168 		*val = sigma_delta->rx_buf[0];  in ad_sd_read_reg()
171 		ret = -EINVAL;  in ad_sd_read_reg()
181  * ad_sd_reset() - Reset the serial interface
183  * @sigma_delta: The sigma delta device
189 	unsigned int reset_length = sigma_delta->info->num_resetclks;  in ad_sd_reset()
197 		return -ENOMEM;  in ad_sd_reset()
200 	ret = spi_write(sigma_delta->spi, buf, size);  in ad_sd_reset()
209 	guard(spinlock_irqsave)(&sigma_delta->irq_lock);  in ad_sd_disable_irq()
212 	if (sigma_delta->irq_dis)  in ad_sd_disable_irq()
215 	sigma_delta->irq_dis = true;  in ad_sd_disable_irq()
216 	disable_irq_nosync(sigma_delta->irq_line);  in ad_sd_disable_irq()
222 	guard(spinlock_irqsave)(&sigma_delta->irq_lock);  in ad_sd_enable_irq()
224 	sigma_delta->irq_dis = false;  in ad_sd_enable_irq()
225 	enable_irq(sigma_delta->irq_line);  in ad_sd_enable_irq()
230 /* Called with `sigma_delta->bus_locked == true` only. */
234 	unsigned int data_read_len = BITS_TO_BYTES(sigma_delta->info->num_resetclks);  in ad_sigma_delta_clear_pending_event()
250 	if (sigma_delta->rdy_gpiod) {  in ad_sigma_delta_clear_pending_event()
251 		pending_event = gpiod_get_value(sigma_delta->rdy_gpiod);  in ad_sigma_delta_clear_pending_event()
278 		return -ENOMEM;  in ad_sigma_delta_clear_pending_event()
281 	if (sigma_delta->info->has_registers) {  in ad_sigma_delta_clear_pending_event()
282 		unsigned int data_reg = sigma_delta->info->data_reg ?: AD_SD_REG_DATA;  in ad_sigma_delta_clear_pending_event()
284 		data[0] = data_reg << sigma_delta->info->addr_shift;  in ad_sigma_delta_clear_pending_event()
285 		data[0] |= sigma_delta->info->read_mask;  in ad_sigma_delta_clear_pending_event()
286 		data[0] |= sigma_delta->comm;  in ad_sigma_delta_clear_pending_event()
294 	 * `data_read_len - 1` bytes are less than $num_resetclks ones.  in ad_sigma_delta_clear_pending_event()
298 	memset(data + 2, 0xff, data_read_len - 1);  in ad_sigma_delta_clear_pending_event()
301 	ret = spi_sync_locked(sigma_delta->spi, &m);  in ad_sigma_delta_clear_pending_event()
318 	spi_bus_lock(sigma_delta->spi->controller);  in ad_sd_calibrate()
319 	sigma_delta->bus_locked = true;  in ad_sd_calibrate()
320 	sigma_delta->keep_cs_asserted = true;  in ad_sd_calibrate()
321 	reinit_completion(&sigma_delta->completion);  in ad_sd_calibrate()
332 	time_left = wait_for_completion_timeout(&sigma_delta->completion, 2 * HZ);  in ad_sd_calibrate()
335 		ret = -EIO;  in ad_sd_calibrate()
340 	sigma_delta->keep_cs_asserted = false;  in ad_sd_calibrate()
343 	sigma_delta->bus_locked = false;  in ad_sd_calibrate()
344 	spi_bus_unlock(sigma_delta->spi->controller);  in ad_sd_calibrate()
351  * ad_sd_calibrate_all() - Performs channel calibration
352  * @sigma_delta: The sigma delta device
375  * ad_sigma_delta_single_conversion() - Performs a single data conversion
394 	ad_sigma_delta_set_channel(sigma_delta, chan->address);  in ad_sigma_delta_single_conversion()
396 	spi_bus_lock(sigma_delta->spi->controller);  in ad_sigma_delta_single_conversion()
397 	sigma_delta->bus_locked = true;  in ad_sigma_delta_single_conversion()
398 	sigma_delta->keep_cs_asserted = true;  in ad_sigma_delta_single_conversion()
399 	reinit_completion(&sigma_delta->completion);  in ad_sigma_delta_single_conversion()
409 			&sigma_delta->completion, HZ);  in ad_sigma_delta_single_conversion()
412 		ret = -EIO;  in ad_sigma_delta_single_conversion()
416 	if (sigma_delta->info->data_reg != 0)  in ad_sigma_delta_single_conversion()
417 		data_reg = sigma_delta->info->data_reg;  in ad_sigma_delta_single_conversion()
422 		DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8),  in ad_sigma_delta_single_conversion()
429 	ad_sigma_delta_disable_one(sigma_delta, chan->address);  in ad_sigma_delta_single_conversion()
432 	sigma_delta->keep_cs_asserted = false;  in ad_sigma_delta_single_conversion()
433 	sigma_delta->bus_locked = false;  in ad_sigma_delta_single_conversion()
434 	spi_bus_unlock(sigma_delta->spi->controller);  in ad_sigma_delta_single_conversion()
440 	sample = raw_sample >> chan->scan_type.shift;  in ad_sigma_delta_single_conversion()
441 	sample &= (1 << chan->scan_type.realbits) - 1;  in ad_sigma_delta_single_conversion()
460 	if (sigma_delta->num_slots == 1) {  in ad_sd_buffer_postenable()
461 		channel = find_first_bit(indio_dev->active_scan_mask,  in ad_sd_buffer_postenable()
464 						 indio_dev->channels[channel].address);  in ad_sd_buffer_postenable()
471 		 * For sigma-delta sequencer drivers with multiple slots, an update_scan_mode  in ad_sd_buffer_postenable()
476 			sigma_delta->slots[slot] = indio_dev->channels[i].address;  in ad_sd_buffer_postenable()
481 	sigma_delta->active_slots = slot;  in ad_sd_buffer_postenable()
482 	sigma_delta->current_slot = 0;  in ad_sd_buffer_postenable()
484 	if (sigma_delta->active_slots > 1) {  in ad_sd_buffer_postenable()
490 	samples_buf_size = ALIGN(slot * indio_dev->channels[0].scan_type.storagebits, 8);  in ad_sd_buffer_postenable()
492 	samples_buf = devm_krealloc(&sigma_delta->spi->dev, sigma_delta->samples_buf,  in ad_sd_buffer_postenable()
495 		return -ENOMEM;  in ad_sd_buffer_postenable()
497 	sigma_delta->samples_buf = samples_buf;  in ad_sd_buffer_postenable()
499 	spi_bus_lock(sigma_delta->spi->controller);  in ad_sd_buffer_postenable()
500 	sigma_delta->bus_locked = true;  in ad_sd_buffer_postenable()
501 	sigma_delta->keep_cs_asserted = true;  in ad_sd_buffer_postenable()
516 	spi_bus_unlock(sigma_delta->spi->controller);  in ad_sd_buffer_postenable()
525 	reinit_completion(&sigma_delta->completion);  in ad_sd_buffer_postdisable()
526 	wait_for_completion_timeout(&sigma_delta->completion, HZ);  in ad_sd_buffer_postdisable()
530 	sigma_delta->keep_cs_asserted = false;  in ad_sd_buffer_postdisable()
533 	if (sigma_delta->status_appended)  in ad_sd_buffer_postdisable()
537 	sigma_delta->bus_locked = false;  in ad_sd_buffer_postdisable()
538 	return spi_bus_unlock(sigma_delta->spi->controller);  in ad_sd_buffer_postdisable()
544 	struct iio_dev *indio_dev = pf->indio_dev;  in ad_sd_trigger_handler()
546 	uint8_t *data = sigma_delta->rx_buf;  in ad_sd_trigger_handler()
554 	reg_size = indio_dev->channels[0].scan_type.realbits +  in ad_sd_trigger_handler()
555 			indio_dev->channels[0].scan_type.shift;  in ad_sd_trigger_handler()
558 	if (sigma_delta->info->data_reg != 0)  in ad_sd_trigger_handler()
559 		data_reg = sigma_delta->info->data_reg;  in ad_sd_trigger_handler()
564 	if (sigma_delta->status_appended)  in ad_sd_trigger_handler()
594 	if (sigma_delta->active_slots == 1) {  in ad_sd_trigger_handler()
595 		iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp);  in ad_sd_trigger_handler()
599 	if (sigma_delta->status_appended) {  in ad_sd_trigger_handler()
602 		converted_channel = data[status_pos] & sigma_delta->info->status_ch_mask;  in ad_sd_trigger_handler()
603 		if (converted_channel != sigma_delta->slots[sigma_delta->current_slot]) {  in ad_sd_trigger_handler()
609 			sigma_delta->current_slot = 0;  in ad_sd_trigger_handler()
614 	sample_size = indio_dev->channels[0].scan_type.storagebits / 8;  in ad_sd_trigger_handler()
615 	sample_pos = sample_size * sigma_delta->current_slot;  in ad_sd_trigger_handler()
616 	memcpy(&sigma_delta->samples_buf[sample_pos], data, sample_size);  in ad_sd_trigger_handler()
617 	sigma_delta->current_slot++;  in ad_sd_trigger_handler()
619 	if (sigma_delta->current_slot == sigma_delta->active_slots) {  in ad_sd_trigger_handler()
620 		sigma_delta->current_slot = 0;  in ad_sd_trigger_handler()
621 		iio_push_to_buffers_with_timestamp(indio_dev, sigma_delta->samples_buf,  in ad_sd_trigger_handler()
622 						   pf->timestamp);  in ad_sd_trigger_handler()
626 	iio_trigger_notify_done(indio_dev->trig);  in ad_sd_trigger_handler()
636 	return bitmap_weight(mask, iio_get_masklength(indio_dev)) <= sigma_delta->num_slots;  in ad_sd_validate_scan_mask()
656 	 * off-limits as reading that would trigger another irq event.  in ad_sd_data_rdy_trig_poll()
665 	if ((!sigma_delta->rdy_gpiod || gpiod_get_value(sigma_delta->rdy_gpiod)) &&  in ad_sd_data_rdy_trig_poll()
667 		complete(&sigma_delta->completion);  in ad_sd_data_rdy_trig_poll()
668 		iio_trigger_poll(sigma_delta->trig);  in ad_sd_data_rdy_trig_poll()
677  * ad_sd_validate_trigger() - validate_trigger callback for ad_sigma_delta devices
682  * device, -EINVAL otherwise.
688 	if (sigma_delta->trig != trig)  in ad_sd_validate_trigger()
689 		return -EINVAL;  in ad_sd_validate_trigger()
698 	unsigned long irq_flags = irq_get_trigger_type(sigma_delta->irq_line);  in devm_ad_sd_probe_trigger()
701 	if (dev != &sigma_delta->spi->dev) {  in devm_ad_sd_probe_trigger()
703 			dev_name(dev), dev_name(&sigma_delta->spi->dev));  in devm_ad_sd_probe_trigger()
704 		return -EFAULT;  in devm_ad_sd_probe_trigger()
707 	sigma_delta->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,  in devm_ad_sd_probe_trigger()
709 	if (sigma_delta->trig == NULL)  in devm_ad_sd_probe_trigger()
710 		return -ENOMEM;  in devm_ad_sd_probe_trigger()
712 	init_completion(&sigma_delta->completion);  in devm_ad_sd_probe_trigger()
714 	sigma_delta->irq_dis = true;  in devm_ad_sd_probe_trigger()
717 	irq_set_status_flags(sigma_delta->irq_line, IRQ_DISABLE_UNLAZY);  in devm_ad_sd_probe_trigger()
721 		irq_flags = sigma_delta->info->irq_flags;  in devm_ad_sd_probe_trigger()
723 	ret = devm_request_irq(dev, sigma_delta->irq_line,  in devm_ad_sd_probe_trigger()
726 			       indio_dev->name,  in devm_ad_sd_probe_trigger()
731 	iio_trigger_set_drvdata(sigma_delta->trig, sigma_delta);  in devm_ad_sd_probe_trigger()
733 	ret = devm_iio_trigger_register(dev, sigma_delta->trig);  in devm_ad_sd_probe_trigger()
738 	indio_dev->trig = iio_trigger_get(sigma_delta->trig);  in devm_ad_sd_probe_trigger()
744  * devm_ad_sd_setup_buffer_and_trigger() - Device-managed buffer & trigger setup
745  * @dev: Device object to which to bind the life-time of the resources attached
753 	sigma_delta->slots = devm_kcalloc(dev, sigma_delta->num_slots,  in devm_ad_sd_setup_buffer_and_trigger()
754 					  sizeof(*sigma_delta->slots), GFP_KERNEL);  in devm_ad_sd_setup_buffer_and_trigger()
755 	if (!sigma_delta->slots)  in devm_ad_sd_setup_buffer_and_trigger()
756 		return -ENOMEM;  in devm_ad_sd_setup_buffer_and_trigger()
770  * ad_sd_init() - Initializes a ad_sigma_delta struct
772  * @indio_dev: The IIO device which the Sigma Delta device is used for
782 	sigma_delta->spi = spi;  in ad_sd_init()
783 	sigma_delta->info = info;  in ad_sd_init()
786 	if (!info->num_slots)  in ad_sd_init()
787 		sigma_delta->num_slots = 1;  in ad_sd_init()
789 		sigma_delta->num_slots = info->num_slots;  in ad_sd_init()
791 	if (sigma_delta->num_slots > 1) {  in ad_sd_init()
792 		if (!indio_dev->info->update_scan_mode) {  in ad_sd_init()
793 			dev_err(&spi->dev, "iio_dev lacks update_scan_mode().\n");  in ad_sd_init()
794 			return -EINVAL;  in ad_sd_init()
797 		if (!info->disable_all) {  in ad_sd_init()
798 			dev_err(&spi->dev, "ad_sigma_delta_info lacks disable_all().\n");  in ad_sd_init()
799 			return -EINVAL;  in ad_sd_init()
803 	spin_lock_init(&sigma_delta->irq_lock);  in ad_sd_init()
805 	if (info->irq_line)  in ad_sd_init()
806 		sigma_delta->irq_line = info->irq_line;  in ad_sd_init()
808 		sigma_delta->irq_line = spi->irq;  in ad_sd_init()
810 	sigma_delta->rdy_gpiod = devm_gpiod_get_optional(&spi->dev, "rdy", GPIOD_IN);  in ad_sd_init()
811 	if (IS_ERR(sigma_delta->rdy_gpiod))  in ad_sd_init()
812 		return dev_err_probe(&spi->dev, PTR_ERR(sigma_delta->rdy_gpiod),  in ad_sd_init()
815 	if (sigma_delta->rdy_gpiod && !sigma_delta->irq_line) {  in ad_sd_init()
816 		sigma_delta->irq_line = gpiod_to_irq(sigma_delta->rdy_gpiod);  in ad_sd_init()
817 		if (sigma_delta->irq_line < 0)  in ad_sd_init()
818 			return sigma_delta->irq_line;  in ad_sd_init()
827 MODULE_AUTHOR("Lars-Peter Clausen <[email protected]>");
828 MODULE_DESCRIPTION("Analog Devices Sigma-Delta ADCs");