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
adis_update_scan_mode(struct iio_dev * indio_dev,const unsigned long * scan_mask)23 int 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 }
74 EXPORT_SYMBOL_GPL(adis_update_scan_mode);
75
adis_trigger_handler(int irq,void * p)76 static 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 /* Guaranteed to be aligned with 8 byte boundary */
106 if (indio_dev->scan_timestamp) {
107 void *b = adis->buffer + indio_dev->scan_bytes - sizeof(s64);
108 *(s64 *)b = pf->timestamp;
109 }
110
111 iio_push_to_buffers(indio_dev, adis->buffer);
112
113 iio_trigger_notify_done(indio_dev->trig);
114
115 return IRQ_HANDLED;
116 }
117
118 /**
119 * adis_setup_buffer_and_trigger() - Sets up buffer and trigger for the adis device
120 * @adis: The adis device.
121 * @indio_dev: The IIO device.
122 * @trigger_handler: Optional trigger handler, may be NULL.
123 *
124 * Returns 0 on success, a negative error code otherwise.
125 *
126 * This function sets up the buffer and trigger for a adis devices. If
127 * 'trigger_handler' is NULL the default trigger handler will be used. The
128 * default trigger handler will simply read the registers assigned to the
129 * currently active channels.
130 *
131 * adis_cleanup_buffer_and_trigger() should be called to free the resources
132 * allocated by this function.
133 */
adis_setup_buffer_and_trigger(struct adis * adis,struct iio_dev * indio_dev,irqreturn_t (* trigger_handler)(int,void *))134 int adis_setup_buffer_and_trigger(struct adis *adis, struct iio_dev *indio_dev,
135 irqreturn_t (*trigger_handler)(int, void *))
136 {
137 int ret;
138
139 if (!trigger_handler)
140 trigger_handler = adis_trigger_handler;
141
142 ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
143 trigger_handler, NULL);
144 if (ret)
145 return ret;
146
147 if (adis->spi->irq) {
148 ret = adis_probe_trigger(adis, indio_dev);
149 if (ret)
150 goto error_buffer_cleanup;
151 }
152 return 0;
153
154 error_buffer_cleanup:
155 iio_triggered_buffer_cleanup(indio_dev);
156 return ret;
157 }
158 EXPORT_SYMBOL_GPL(adis_setup_buffer_and_trigger);
159
160 /**
161 * adis_cleanup_buffer_and_trigger() - Free buffer and trigger resources
162 * @adis: The adis device.
163 * @indio_dev: The IIO device.
164 *
165 * Frees resources allocated by adis_setup_buffer_and_trigger()
166 */
adis_cleanup_buffer_and_trigger(struct adis * adis,struct iio_dev * indio_dev)167 void adis_cleanup_buffer_and_trigger(struct adis *adis,
168 struct iio_dev *indio_dev)
169 {
170 if (adis->spi->irq)
171 adis_remove_trigger(adis);
172 kfree(adis->buffer);
173 kfree(adis->xfer);
174 iio_triggered_buffer_cleanup(indio_dev);
175 }
176 EXPORT_SYMBOL_GPL(adis_cleanup_buffer_and_trigger);
177