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, burst_max_length;
27	u8 *tx;
28
29	burst_length = adis->data->burst_len + adis->burst_extra_len;
30
31	if (adis->data->burst_max_len)
32		burst_max_length = adis->data->burst_max_len;
33	else
34		burst_max_length = burst_length;
35
36	adis->xfer = kcalloc(2, sizeof(*adis->xfer), GFP_KERNEL);
37	if (!adis->xfer)
38		return -ENOMEM;
39
40	adis->buffer = kzalloc(burst_max_length + sizeof(u16), GFP_KERNEL);
41	if (!adis->buffer) {
42		kfree(adis->xfer);
43		adis->xfer = NULL;
44		return -ENOMEM;
45	}
46
47	tx = adis->buffer + burst_max_length;
48	tx[0] = ADIS_READ_REG(adis->data->burst_reg_cmd);
49	tx[1] = 0;
50
51	adis->xfer[0].tx_buf = tx;
52	adis->xfer[0].bits_per_word = 8;
53	adis->xfer[0].len = 2;
54	adis->xfer[1].rx_buf = adis->buffer;
55	adis->xfer[1].bits_per_word = 8;
56	adis->xfer[1].len = burst_length;
57
58	spi_message_init(&adis->msg);
59	spi_message_add_tail(&adis->xfer[0], &adis->msg);
60	spi_message_add_tail(&adis->xfer[1], &adis->msg);
61
62	return 0;
63}
64
65int adis_update_scan_mode(struct iio_dev *indio_dev,
66			  const unsigned long *scan_mask)
67{
68	struct adis *adis = iio_device_get_drvdata(indio_dev);
69	const struct iio_chan_spec *chan;
70	unsigned int scan_count;
71	unsigned int i, j;
72	__be16 *tx, *rx;
73
74	kfree(adis->xfer);
75	kfree(adis->buffer);
76
77	if (adis->data->burst_len)
78		return adis_update_scan_mode_burst(indio_dev, scan_mask);
79
80	scan_count = indio_dev->scan_bytes / 2;
81
82	adis->xfer = kcalloc(scan_count + 1, sizeof(*adis->xfer), GFP_KERNEL);
83	if (!adis->xfer)
84		return -ENOMEM;
85
86	adis->buffer = kcalloc(indio_dev->scan_bytes, 2, GFP_KERNEL);
87	if (!adis->buffer) {
88		kfree(adis->xfer);
89		adis->xfer = NULL;
90		return -ENOMEM;
91	}
92
93	rx = adis->buffer;
94	tx = rx + scan_count;
95
96	spi_message_init(&adis->msg);
97
98	for (j = 0; j <= scan_count; j++) {
99		adis->xfer[j].bits_per_word = 8;
100		if (j != scan_count)
101			adis->xfer[j].cs_change = 1;
102		adis->xfer[j].len = 2;
103		adis->xfer[j].delay.value = adis->data->read_delay;
104		adis->xfer[j].delay.unit = SPI_DELAY_UNIT_USECS;
105		if (j < scan_count)
106			adis->xfer[j].tx_buf = &tx[j];
107		if (j >= 1)
108			adis->xfer[j].rx_buf = &rx[j - 1];
109		spi_message_add_tail(&adis->xfer[j], &adis->msg);
110	}
111
112	chan = indio_dev->channels;
113	for (i = 0; i < indio_dev->num_channels; i++, chan++) {
114		if (!test_bit(chan->scan_index, scan_mask))
115			continue;
116		if (chan->scan_type.storagebits == 32)
117			*tx++ = cpu_to_be16((chan->address + 2) << 8);
118		*tx++ = cpu_to_be16(chan->address << 8);
119	}
120
121	return 0;
122}
123EXPORT_SYMBOL_NS_GPL(adis_update_scan_mode, IIO_ADISLIB);
124
125static irqreturn_t adis_trigger_handler(int irq, void *p)
126{
127	struct iio_poll_func *pf = p;
128	struct iio_dev *indio_dev = pf->indio_dev;
129	struct adis *adis = iio_device_get_drvdata(indio_dev);
130	int ret;
131
132	if (adis->data->has_paging) {
133		mutex_lock(&adis->state_lock);
134		if (adis->current_page != 0) {
135			adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
136			adis->tx[1] = 0;
137			spi_write(adis->spi, adis->tx, 2);
138		}
139	}
140
141	ret = spi_sync(adis->spi, &adis->msg);
142	if (ret)
143		dev_err(&adis->spi->dev, "Failed to read data: %d", ret);
144
145
146	if (adis->data->has_paging) {
147		adis->current_page = 0;
148		mutex_unlock(&adis->state_lock);
149	}
150
151	iio_push_to_buffers_with_timestamp(indio_dev, adis->buffer,
152					   pf->timestamp);
153
154	iio_trigger_notify_done(indio_dev->trig);
155
156	return IRQ_HANDLED;
157}
158
159static void adis_buffer_cleanup(void *arg)
160{
161	struct adis *adis = arg;
162
163	kfree(adis->buffer);
164	kfree(adis->xfer);
165}
166
167/**
168 * devm_adis_setup_buffer_and_trigger() - Sets up buffer and trigger for
169 *					  the managed adis device
170 * @adis: The adis device
171 * @indio_dev: The IIO device
172 * @trigger_handler: Optional trigger handler, may be NULL.
173 *
174 * Returns 0 on success, a negative error code otherwise.
175 *
176 * This function sets up the buffer and trigger for a adis devices.  If
177 * 'trigger_handler' is NULL the default trigger handler will be used. The
178 * default trigger handler will simply read the registers assigned to the
179 * currently active channels.
180 */
181int
182devm_adis_setup_buffer_and_trigger(struct adis *adis, struct iio_dev *indio_dev,
183				   irq_handler_t trigger_handler)
184{
185	int ret;
186
187	if (!trigger_handler)
188		trigger_handler = adis_trigger_handler;
189
190	ret = devm_iio_triggered_buffer_setup(&adis->spi->dev, indio_dev,
191					      &iio_pollfunc_store_time,
192					      trigger_handler, NULL);
193	if (ret)
194		return ret;
195
196	if (adis->spi->irq) {
197		ret = devm_adis_probe_trigger(adis, indio_dev);
198		if (ret)
199			return ret;
200	}
201
202	return devm_add_action_or_reset(&adis->spi->dev, adis_buffer_cleanup,
203					adis);
204}
205EXPORT_SYMBOL_NS_GPL(devm_adis_setup_buffer_and_trigger, IIO_ADISLIB);
206
207