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