1 // SPDX-License-Identifier: GPL-2.0-only
3  * Support code for Analog Devices Sigma-Delta ADCs
6  *  Author: Lars-Peter Clausen <lars@metafoo.de>
31 #include <linux/iio/buffer-dmaengine.h>
47  * ad_sd_set_comm() - Set communications register
49  * @sigma_delta: The sigma delta device
56 	sigma_delta->comm = comm & AD_SD_COMM_CHAN_MASK;  in ad_sd_set_comm()
61  * ad_sd_write_reg() - Write a register
63  * @sigma_delta: The sigma delta device
65  * @size: Size of the register (0-3)
73 	u8 *data = sigma_delta->tx_buf;  in ad_sd_write_reg()
77 		.cs_change	= sigma_delta->keep_cs_asserted,  in ad_sd_write_reg()
82 	data[0] = (reg << sigma_delta->info->addr_shift) | sigma_delta->comm;  in ad_sd_write_reg()
97 		return -EINVAL;  in ad_sd_write_reg()
103 	if (sigma_delta->bus_locked)  in ad_sd_write_reg()
104 		ret = spi_sync_locked(sigma_delta->spi, &m);  in ad_sd_write_reg()
106 		ret = spi_sync(sigma_delta->spi, &m);  in ad_sd_write_reg()
115 	data[0] = reg << sigma_delta->info->addr_shift;  in ad_sd_set_read_reg_addr()
116 	data[0] |= sigma_delta->info->read_mask;  in ad_sd_set_read_reg_addr()
117 	data[0] |= sigma_delta->comm;  in ad_sd_set_read_reg_addr()
123 	u8 *data = sigma_delta->tx_buf;  in ad_sd_read_reg_raw()
132 			.cs_change = sigma_delta->keep_cs_asserted,  in ad_sd_read_reg_raw()
139 	if (sigma_delta->info->has_registers) {  in ad_sd_read_reg_raw()
145 	if (sigma_delta->bus_locked)  in ad_sd_read_reg_raw()
146 		ret = spi_sync_locked(sigma_delta->spi, &m);  in ad_sd_read_reg_raw()
148 		ret = spi_sync(sigma_delta->spi, &m);  in ad_sd_read_reg_raw()
154  * ad_sd_read_reg() - Read a register
156  * @sigma_delta: The sigma delta device
158  * @size: Size of the register (1-4)
168 	ret = ad_sd_read_reg_raw(sigma_delta, reg, size, sigma_delta->rx_buf);  in ad_sd_read_reg()
174 		*val = get_unaligned_be32(sigma_delta->rx_buf);  in ad_sd_read_reg()
177 		*val = get_unaligned_be24(sigma_delta->rx_buf);  in ad_sd_read_reg()
180 		*val = get_unaligned_be16(sigma_delta->rx_buf);  in ad_sd_read_reg()
183 		*val = sigma_delta->rx_buf[0];  in ad_sd_read_reg()
186 		ret = -EINVAL;  in ad_sd_read_reg()
196  * ad_sd_reset() - Reset the serial interface
198  * @sigma_delta: The sigma delta device
204 	unsigned int reset_length = sigma_delta->info->num_resetclks;  in ad_sd_reset()
212 		return -ENOMEM;  in ad_sd_reset()
215 	ret = spi_write(sigma_delta->spi, buf, size);  in ad_sd_reset()
224 	guard(spinlock_irqsave)(&sigma_delta->irq_lock);  in ad_sd_disable_irq()
227 	if (sigma_delta->irq_dis)  in ad_sd_disable_irq()
230 	sigma_delta->irq_dis = true;  in ad_sd_disable_irq()
231 	disable_irq_nosync(sigma_delta->irq_line);  in ad_sd_disable_irq()
237 	guard(spinlock_irqsave)(&sigma_delta->irq_lock);  in ad_sd_enable_irq()
239 	sigma_delta->irq_dis = false;  in ad_sd_enable_irq()
240 	enable_irq(sigma_delta->irq_line);  in ad_sd_enable_irq()
245 /* Called with `sigma_delta->bus_locked == true` only. */
249 	unsigned int data_read_len = BITS_TO_BYTES(sigma_delta->info->num_resetclks);  in ad_sigma_delta_clear_pending_event()
265 	if (sigma_delta->rdy_gpiod) {  in ad_sigma_delta_clear_pending_event()
266 		pending_event = gpiod_get_value(sigma_delta->rdy_gpiod);  in ad_sigma_delta_clear_pending_event()
293 		return -ENOMEM;  in ad_sigma_delta_clear_pending_event()
296 	if (sigma_delta->info->has_registers) {  in ad_sigma_delta_clear_pending_event()
297 		unsigned int data_reg = sigma_delta->info->data_reg ?: AD_SD_REG_DATA;  in ad_sigma_delta_clear_pending_event()
307 	 * `data_read_len - 1` bytes are less than $num_resetclks ones.  in ad_sigma_delta_clear_pending_event()
311 	memset(data + 2, 0xff, data_read_len - 1);  in ad_sigma_delta_clear_pending_event()
314 	ret = spi_sync_locked(sigma_delta->spi, &m);  in ad_sigma_delta_clear_pending_event()
331 	spi_bus_lock(sigma_delta->spi->controller);  in ad_sd_calibrate()
332 	sigma_delta->bus_locked = true;  in ad_sd_calibrate()
333 	sigma_delta->keep_cs_asserted = true;  in ad_sd_calibrate()
334 	reinit_completion(&sigma_delta->completion);  in ad_sd_calibrate()
345 	time_left = wait_for_completion_timeout(&sigma_delta->completion, 2 * HZ);  in ad_sd_calibrate()
348 		ret = -EIO;  in ad_sd_calibrate()
353 	sigma_delta->keep_cs_asserted = false;  in ad_sd_calibrate()
356 	sigma_delta->bus_locked = false;  in ad_sd_calibrate()
357 	spi_bus_unlock(sigma_delta->spi->controller);  in ad_sd_calibrate()
364  * ad_sd_calibrate_all() - Performs channel calibration
365  * @sigma_delta: The sigma delta device
388  * ad_sigma_delta_single_conversion() - Performs a single data conversion
404 		return -EBUSY;  in ad_sigma_delta_single_conversion()
406 	ret = ad_sigma_delta_set_channel(sigma_delta, chan->address);  in ad_sigma_delta_single_conversion()
410 	spi_bus_lock(sigma_delta->spi->controller);  in ad_sigma_delta_single_conversion()
411 	sigma_delta->bus_locked = true;  in ad_sigma_delta_single_conversion()
412 	sigma_delta->keep_cs_asserted = true;  in ad_sigma_delta_single_conversion()
413 	reinit_completion(&sigma_delta->completion);  in ad_sigma_delta_single_conversion()
423 			&sigma_delta->completion, HZ);  in ad_sigma_delta_single_conversion()
426 		ret = -EIO;  in ad_sigma_delta_single_conversion()
430 	if (sigma_delta->info->data_reg != 0)  in ad_sigma_delta_single_conversion()
431 		data_reg = sigma_delta->info->data_reg;  in ad_sigma_delta_single_conversion()
436 		BITS_TO_BYTES(chan->scan_type.realbits + chan->scan_type.shift),  in ad_sigma_delta_single_conversion()
443 	ad_sigma_delta_disable_one(sigma_delta, chan->address);  in ad_sigma_delta_single_conversion()
446 	sigma_delta->keep_cs_asserted = false;  in ad_sigma_delta_single_conversion()
447 	sigma_delta->bus_locked = false;  in ad_sigma_delta_single_conversion()
448 	spi_bus_unlock(sigma_delta->spi->controller);  in ad_sigma_delta_single_conversion()
455 	sample = raw_sample >> chan->scan_type.shift;  in ad_sigma_delta_single_conversion()
456 	sample &= (1 << chan->scan_type.realbits) - 1;  in ad_sigma_delta_single_conversion()
470 	const struct iio_scan_type *scan_type = &indio_dev->channels[0].scan_type;  in ad_sd_buffer_postenable()
471 	struct spi_transfer *xfer = sigma_delta->sample_xfer;  in ad_sd_buffer_postenable()
476 	if (sigma_delta->num_slots == 1) {  in ad_sd_buffer_postenable()
477 		channel = find_first_bit(indio_dev->active_scan_mask,  in ad_sd_buffer_postenable()
480 						 indio_dev->channels[channel].address);  in ad_sd_buffer_postenable()
487 		 * For sigma-delta sequencer drivers with multiple slots, an update_scan_mode  in ad_sd_buffer_postenable()
492 			sigma_delta->slots[slot] = indio_dev->channels[i].address;  in ad_sd_buffer_postenable()
497 	sigma_delta->active_slots = slot;  in ad_sd_buffer_postenable()
498 	sigma_delta->current_slot = 0;  in ad_sd_buffer_postenable()
502 		xfer[1].bits_per_word = scan_type->realbits;  in ad_sd_buffer_postenable()
503 		xfer[1].len = spi_bpw_to_bytes(scan_type->realbits);  in ad_sd_buffer_postenable()
507 		if (sigma_delta->active_slots > 1) {  in ad_sd_buffer_postenable()
514 			ALIGN(slot * BITS_TO_BYTES(scan_type->storagebits),  in ad_sd_buffer_postenable()
517 		samples_buf = devm_krealloc(&sigma_delta->spi->dev,  in ad_sd_buffer_postenable()
518 					    sigma_delta->samples_buf,  in ad_sd_buffer_postenable()
521 			return -ENOMEM;  in ad_sd_buffer_postenable()
523 		sigma_delta->samples_buf = samples_buf;  in ad_sd_buffer_postenable()
524 		scan_size = BITS_TO_BYTES(scan_type->realbits + scan_type->shift);  in ad_sd_buffer_postenable()
525 		/* For 24-bit data, there is an extra byte of padding. */  in ad_sd_buffer_postenable()
526 		xfer[1].rx_buf = &sigma_delta->rx_buf[scan_size == 3 ? 1 : 0];  in ad_sd_buffer_postenable()
527 		xfer[1].len = scan_size + (sigma_delta->status_appended ? 1 : 0);  in ad_sd_buffer_postenable()
531 	if (sigma_delta->info->has_registers) {  in ad_sd_buffer_postenable()
532 		xfer[0].tx_buf = &sigma_delta->sample_addr;  in ad_sd_buffer_postenable()
536 					sigma_delta->info->data_reg ?: AD_SD_REG_DATA,  in ad_sd_buffer_postenable()
537 					&sigma_delta->sample_addr);  in ad_sd_buffer_postenable()
538 		spi_message_init_with_transfers(&sigma_delta->sample_msg, xfer, 2);  in ad_sd_buffer_postenable()
540 		spi_message_init_with_transfers(&sigma_delta->sample_msg,  in ad_sd_buffer_postenable()
544 	sigma_delta->sample_msg.offload = sigma_delta->offload;  in ad_sd_buffer_postenable()
546 	ret = spi_optimize_message(sigma_delta->spi, &sigma_delta->sample_msg);  in ad_sd_buffer_postenable()
550 	spi_bus_lock(sigma_delta->spi->controller);  in ad_sd_buffer_postenable()
551 	sigma_delta->bus_locked = true;  in ad_sd_buffer_postenable()
552 	sigma_delta->keep_cs_asserted = true;  in ad_sd_buffer_postenable()
567 		ret = spi_offload_trigger_enable(sigma_delta->offload,  in ad_sd_buffer_postenable()
568 						 sigma_delta->offload_trigger,  in ad_sd_buffer_postenable()
579 	spi_bus_unlock(sigma_delta->spi->controller);  in ad_sd_buffer_postenable()
580 	spi_unoptimize_message(&sigma_delta->sample_msg);  in ad_sd_buffer_postenable()
590 		spi_offload_trigger_disable(sigma_delta->offload,  in ad_sd_buffer_predisable()
591 					    sigma_delta->offload_trigger);  in ad_sd_buffer_predisable()
593 		reinit_completion(&sigma_delta->completion);  in ad_sd_buffer_predisable()
594 		wait_for_completion_timeout(&sigma_delta->completion, HZ);  in ad_sd_buffer_predisable()
599 	sigma_delta->keep_cs_asserted = false;  in ad_sd_buffer_predisable()
602 	if (sigma_delta->status_appended)  in ad_sd_buffer_predisable()
606 	sigma_delta->bus_locked = false;  in ad_sd_buffer_predisable()
607 	spi_bus_unlock(sigma_delta->spi->controller);  in ad_sd_buffer_predisable()
608 	spi_unoptimize_message(&sigma_delta->sample_msg);  in ad_sd_buffer_predisable()
616 	struct iio_dev *indio_dev = pf->indio_dev;  in ad_sd_trigger_handler()
617 	const struct iio_scan_type *scan_type = &indio_dev->channels[0].scan_type;  in ad_sd_trigger_handler()
619 	u8 *data = sigma_delta->rx_buf;  in ad_sd_trigger_handler()
626 	reg_size = BITS_TO_BYTES(scan_type->realbits + scan_type->shift);  in ad_sd_trigger_handler()
627 	/* For 24-bit data, there is an extra byte of padding. */  in ad_sd_trigger_handler()
630 	ret = spi_sync_locked(sigma_delta->spi, &sigma_delta->sample_msg);  in ad_sd_trigger_handler()
638 	if (sigma_delta->active_slots == 1) {  in ad_sd_trigger_handler()
639 		iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp);  in ad_sd_trigger_handler()
643 	if (sigma_delta->status_appended) {  in ad_sd_trigger_handler()
646 		converted_channel = data[status_pos] & sigma_delta->info->status_ch_mask;  in ad_sd_trigger_handler()
647 		if (converted_channel != sigma_delta->slots[sigma_delta->current_slot]) {  in ad_sd_trigger_handler()
653 			sigma_delta->current_slot = 0;  in ad_sd_trigger_handler()
658 	sample_size = BITS_TO_BYTES(scan_type->storagebits);  in ad_sd_trigger_handler()
659 	sample_pos = sample_size * sigma_delta->current_slot;  in ad_sd_trigger_handler()
660 	memcpy(&sigma_delta->samples_buf[sample_pos], data, sample_size);  in ad_sd_trigger_handler()
661 	sigma_delta->current_slot++;  in ad_sd_trigger_handler()
663 	if (sigma_delta->current_slot == sigma_delta->active_slots) {  in ad_sd_trigger_handler()
664 		sigma_delta->current_slot = 0;  in ad_sd_trigger_handler()
665 		iio_push_to_buffers_with_timestamp(indio_dev, sigma_delta->samples_buf,  in ad_sd_trigger_handler()
666 						   pf->timestamp);  in ad_sd_trigger_handler()
670 	iio_trigger_notify_done(indio_dev->trig);  in ad_sd_trigger_handler()
680 	return bitmap_weight(mask, iio_get_masklength(indio_dev)) <= sigma_delta->num_slots;  in ad_sd_validate_scan_mask()
700 	 * off-limits as reading that would trigger another irq event.  in ad_sd_data_rdy_trig_poll()
709 	if ((!sigma_delta->rdy_gpiod || gpiod_get_value(sigma_delta->rdy_gpiod)) &&  in ad_sd_data_rdy_trig_poll()
711 		complete(&sigma_delta->completion);  in ad_sd_data_rdy_trig_poll()
712 		if (sigma_delta->trig)  in ad_sd_data_rdy_trig_poll()
713 			iio_trigger_poll(sigma_delta->trig);  in ad_sd_data_rdy_trig_poll()
722  * ad_sd_validate_trigger() - validate_trigger callback for ad_sigma_delta devices
727  * device, -EINVAL otherwise.
733 	if (sigma_delta->trig != trig)  in ad_sd_validate_trigger()
734 		return -EINVAL;  in ad_sd_validate_trigger()
743 	unsigned long irq_flags = irq_get_trigger_type(sigma_delta->irq_line);  in devm_ad_sd_probe_trigger()
746 	init_completion(&sigma_delta->completion);  in devm_ad_sd_probe_trigger()
748 	sigma_delta->irq_dis = true;  in devm_ad_sd_probe_trigger()
751 	irq_set_status_flags(sigma_delta->irq_line, IRQ_DISABLE_UNLAZY);  in devm_ad_sd_probe_trigger()
755 		irq_flags = sigma_delta->info->irq_flags;  in devm_ad_sd_probe_trigger()
757 	ret = devm_request_irq(dev, sigma_delta->irq_line,  in devm_ad_sd_probe_trigger()
760 			       indio_dev->name,  in devm_ad_sd_probe_trigger()
766 		sigma_delta->offload_trigger =  in devm_ad_sd_probe_trigger()
767 			devm_spi_offload_trigger_get(dev, sigma_delta->offload,  in devm_ad_sd_probe_trigger()
769 		if (IS_ERR(sigma_delta->offload_trigger))  in devm_ad_sd_probe_trigger()
770 			return dev_err_probe(dev, PTR_ERR(sigma_delta->offload_trigger),  in devm_ad_sd_probe_trigger()
773 		if (dev != &sigma_delta->spi->dev)  in devm_ad_sd_probe_trigger()
774 			return dev_err_probe(dev, -EFAULT,  in devm_ad_sd_probe_trigger()
776 				dev_name(dev), dev_name(&sigma_delta->spi->dev));  in devm_ad_sd_probe_trigger()
778 		sigma_delta->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",  in devm_ad_sd_probe_trigger()
779 			indio_dev->name, iio_device_id(indio_dev));  in devm_ad_sd_probe_trigger()
780 		if (!sigma_delta->trig)  in devm_ad_sd_probe_trigger()
781 			return -ENOMEM;  in devm_ad_sd_probe_trigger()
783 		iio_trigger_set_drvdata(sigma_delta->trig, sigma_delta);  in devm_ad_sd_probe_trigger()
785 		ret = devm_iio_trigger_register(dev, sigma_delta->trig);  in devm_ad_sd_probe_trigger()
790 		indio_dev->trig = iio_trigger_get(sigma_delta->trig);  in devm_ad_sd_probe_trigger()
797  * devm_ad_sd_setup_buffer_and_trigger() - Device-managed buffer & trigger setup
798  * @dev: Device object to which to bind the life-time of the resources attached
806 	sigma_delta->slots = devm_kcalloc(dev, sigma_delta->num_slots,  in devm_ad_sd_setup_buffer_and_trigger()
807 					  sizeof(*sigma_delta->slots), GFP_KERNEL);  in devm_ad_sd_setup_buffer_and_trigger()
808 	if (!sigma_delta->slots)  in devm_ad_sd_setup_buffer_and_trigger()
809 		return -ENOMEM;  in devm_ad_sd_setup_buffer_and_trigger()
815 			sigma_delta->offload);  in devm_ad_sd_setup_buffer_and_trigger()
825 		indio_dev->setup_ops = &ad_sd_buffer_setup_ops;  in devm_ad_sd_setup_buffer_and_trigger()
840  * ad_sd_init() - Initializes a ad_sigma_delta struct
842  * @indio_dev: The IIO device which the Sigma Delta device is used for
852 	sigma_delta->spi = spi;  in ad_sd_init()
853 	sigma_delta->info = info;  in ad_sd_init()
856 	if (!info->num_slots)  in ad_sd_init()
857 		sigma_delta->num_slots = 1;  in ad_sd_init()
859 		sigma_delta->num_slots = info->num_slots;  in ad_sd_init()
861 	if (sigma_delta->num_slots > 1) {  in ad_sd_init()
862 		if (!indio_dev->info->update_scan_mode) {  in ad_sd_init()
863 			dev_err(&spi->dev, "iio_dev lacks update_scan_mode().\n");  in ad_sd_init()
864 			return -EINVAL;  in ad_sd_init()
867 		if (!info->disable_all) {  in ad_sd_init()
868 			dev_err(&spi->dev, "ad_sigma_delta_info lacks disable_all().\n");  in ad_sd_init()
869 			return -EINVAL;  in ad_sd_init()
873 	spin_lock_init(&sigma_delta->irq_lock);  in ad_sd_init()
875 	if (info->has_named_irqs) {  in ad_sd_init()
876 		sigma_delta->irq_line = fwnode_irq_get_byname(dev_fwnode(&spi->dev),  in ad_sd_init()
878 		if (sigma_delta->irq_line < 0)  in ad_sd_init()
879 			return dev_err_probe(&spi->dev, sigma_delta->irq_line,  in ad_sd_init()
882 		sigma_delta->irq_line = spi->irq;  in ad_sd_init()
885 	sigma_delta->rdy_gpiod = devm_gpiod_get_optional(&spi->dev, "rdy", GPIOD_IN);  in ad_sd_init()
886 	if (IS_ERR(sigma_delta->rdy_gpiod))  in ad_sd_init()
887 		return dev_err_probe(&spi->dev, PTR_ERR(sigma_delta->rdy_gpiod),  in ad_sd_init()
890 	if (sigma_delta->rdy_gpiod && !sigma_delta->irq_line) {  in ad_sd_init()
891 		sigma_delta->irq_line = gpiod_to_irq(sigma_delta->rdy_gpiod);  in ad_sd_init()
892 		if (sigma_delta->irq_line < 0)  in ad_sd_init()
893 			return sigma_delta->irq_line;  in ad_sd_init()
896 	if (info->supports_spi_offload) {  in ad_sd_init()
903 		sigma_delta->offload = devm_spi_offload_get(&spi->dev, spi,  in ad_sd_init()
905 		ret = PTR_ERR_OR_ZERO(sigma_delta->offload);  in ad_sd_init()
906 		if (ret && ret != -ENODEV)  in ad_sd_init()
907 			return dev_err_probe(&spi->dev, ret, "Failed to get SPI offload\n");  in ad_sd_init()
916 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
917 MODULE_DESCRIPTION("Analog Devices Sigma-Delta ADCs");