1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Common library for ADIS16XXX devices
  4 *
  5 * Copyright 2012 Analog Devices Inc.
  6 *   Author: Lars-Peter Clausen <lars@metafoo.de>
  7 */
  8
  9#include <linux/export.h>
 10#include <linux/interrupt.h>
 11#include <linux/mutex.h>
 12#include <linux/kernel.h>
 13#include <linux/spi/spi.h>
 14#include <linux/slab.h>
 15
 16#include <linux/iio/iio.h>
 17#include <linux/iio/buffer.h>
 18#include <linux/iio/trigger_consumer.h>
 19#include <linux/iio/triggered_buffer.h>
 20#include <linux/iio/imu/adis.h>
 21
 22static int adis_update_scan_mode_burst(struct iio_dev *indio_dev,
 23	const unsigned long *scan_mask)
 24{
 25	struct adis *adis = iio_device_get_drvdata(indio_dev);
 26	unsigned int burst_length;
 27	u8 *tx;
 28
 29	/* All but the timestamp channel */
 30	burst_length = (indio_dev->num_channels - 1) * sizeof(u16);
 31	burst_length += adis->burst->extra_len;
 32
 33	adis->xfer = kcalloc(2, sizeof(*adis->xfer), GFP_KERNEL);
 34	if (!adis->xfer)
 35		return -ENOMEM;
 36
 37	adis->buffer = kzalloc(burst_length + sizeof(u16), GFP_KERNEL);
 38	if (!adis->buffer) {
 39		kfree(adis->xfer);
 40		adis->xfer = NULL;
 41		return -ENOMEM;
 42	}
 43
 44	tx = adis->buffer + burst_length;
 45	tx[0] = ADIS_READ_REG(adis->burst->reg_cmd);
 46	tx[1] = 0;
 47
 48	adis->xfer[0].tx_buf = tx;
 49	adis->xfer[0].bits_per_word = 8;
 50	adis->xfer[0].len = 2;
 51	adis->xfer[1].rx_buf = adis->buffer;
 52	adis->xfer[1].bits_per_word = 8;
 53	adis->xfer[1].len = burst_length;
 54
 55	spi_message_init(&adis->msg);
 56	spi_message_add_tail(&adis->xfer[0], &adis->msg);
 57	spi_message_add_tail(&adis->xfer[1], &adis->msg);
 58
 59	return 0;
 60}
 61
 62int adis_update_scan_mode(struct iio_dev *indio_dev,
 63	const unsigned long *scan_mask)
 64{
 65	struct adis *adis = iio_device_get_drvdata(indio_dev);
 66	const struct iio_chan_spec *chan;
 67	unsigned int scan_count;
 68	unsigned int i, j;
 69	__be16 *tx, *rx;
 70
 71	kfree(adis->xfer);
 72	kfree(adis->buffer);
 73
 74	if (adis->burst && adis->burst->en)
 75		return adis_update_scan_mode_burst(indio_dev, scan_mask);
 76
 77	scan_count = indio_dev->scan_bytes / 2;
 78
 79	adis->xfer = kcalloc(scan_count + 1, sizeof(*adis->xfer), GFP_KERNEL);
 80	if (!adis->xfer)
 81		return -ENOMEM;
 82
 83	adis->buffer = kcalloc(indio_dev->scan_bytes, 2, GFP_KERNEL);
 84	if (!adis->buffer) {
 85		kfree(adis->xfer);
 86		adis->xfer = NULL;
 87		return -ENOMEM;
 88	}
 89
 90	rx = adis->buffer;
 91	tx = rx + scan_count;
 92
 93	spi_message_init(&adis->msg);
 94
 95	for (j = 0; j <= scan_count; j++) {
 96		adis->xfer[j].bits_per_word = 8;
 97		if (j != scan_count)
 98			adis->xfer[j].cs_change = 1;
 99		adis->xfer[j].len = 2;
100		adis->xfer[j].delay_usecs = adis->data->read_delay;
101		if (j < scan_count)
102			adis->xfer[j].tx_buf = &tx[j];
103		if (j >= 1)
104			adis->xfer[j].rx_buf = &rx[j - 1];
105		spi_message_add_tail(&adis->xfer[j], &adis->msg);
106	}
107
108	chan = indio_dev->channels;
109	for (i = 0; i < indio_dev->num_channels; i++, chan++) {
110		if (!test_bit(chan->scan_index, scan_mask))
111			continue;
112		if (chan->scan_type.storagebits == 32)
113			*tx++ = cpu_to_be16((chan->address + 2) << 8);
114		*tx++ = cpu_to_be16(chan->address << 8);
115	}
116
117	return 0;
118}
119EXPORT_SYMBOL_GPL(adis_update_scan_mode);
120
121static irqreturn_t adis_trigger_handler(int irq, void *p)
122{
123	struct iio_poll_func *pf = p;
124	struct iio_dev *indio_dev = pf->indio_dev;
125	struct adis *adis = iio_device_get_drvdata(indio_dev);
126	int ret;
127
128	if (!adis->buffer)
129		return -ENOMEM;
130
131	if (adis->data->has_paging) {
132		mutex_lock(&adis->txrx_lock);
133		if (adis->current_page != 0) {
134			adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
135			adis->tx[1] = 0;
136			spi_write(adis->spi, adis->tx, 2);
137		}
138	}
139
140	ret = spi_sync(adis->spi, &adis->msg);
141	if (ret)
142		dev_err(&adis->spi->dev, "Failed to read data: %d", ret);
143
144
145	if (adis->data->has_paging) {
146		adis->current_page = 0;
147		mutex_unlock(&adis->txrx_lock);
148	}
149
150	iio_push_to_buffers_with_timestamp(indio_dev, adis->buffer,
151		pf->timestamp);
152
153	iio_trigger_notify_done(indio_dev->trig);
154
155	return IRQ_HANDLED;
156}
157
158/**
159 * adis_setup_buffer_and_trigger() - Sets up buffer and trigger for the adis device
160 * @adis: The adis device.
161 * @indio_dev: The IIO device.
162 * @trigger_handler: Optional trigger handler, may be NULL.
163 *
164 * Returns 0 on success, a negative error code otherwise.
165 *
166 * This function sets up the buffer and trigger for a adis devices.  If
167 * 'trigger_handler' is NULL the default trigger handler will be used. The
168 * default trigger handler will simply read the registers assigned to the
169 * currently active channels.
170 *
171 * adis_cleanup_buffer_and_trigger() should be called to free the resources
172 * allocated by this function.
173 */
174int adis_setup_buffer_and_trigger(struct adis *adis, struct iio_dev *indio_dev,
175	irqreturn_t (*trigger_handler)(int, void *))
176{
177	int ret;
178
179	if (!trigger_handler)
180		trigger_handler = adis_trigger_handler;
181
182	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
183		trigger_handler, NULL);
184	if (ret)
185		return ret;
186
187	if (adis->spi->irq) {
188		ret = adis_probe_trigger(adis, indio_dev);
189		if (ret)
190			goto error_buffer_cleanup;
191	}
192	return 0;
193
194error_buffer_cleanup:
195	iio_triggered_buffer_cleanup(indio_dev);
196	return ret;
197}
198EXPORT_SYMBOL_GPL(adis_setup_buffer_and_trigger);
199
200/**
201 * adis_cleanup_buffer_and_trigger() - Free buffer and trigger resources
202 * @adis: The adis device.
203 * @indio_dev: The IIO device.
204 *
205 * Frees resources allocated by adis_setup_buffer_and_trigger()
206 */
207void adis_cleanup_buffer_and_trigger(struct adis *adis,
208	struct iio_dev *indio_dev)
209{
210	if (adis->spi->irq)
211		adis_remove_trigger(adis);
212	kfree(adis->buffer);
213	kfree(adis->xfer);
214	iio_triggered_buffer_cleanup(indio_dev);
215}
216EXPORT_SYMBOL_GPL(adis_cleanup_buffer_and_trigger);