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
adis_update_scan_mode_burst(struct iio_dev * indio_dev,const unsigned long * scan_mask)22 static 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
adis_update_scan_mode(struct iio_dev * indio_dev,const unsigned long * scan_mask)62 int 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 }
119 EXPORT_SYMBOL_GPL(adis_update_scan_mode);
120
adis_trigger_handler(int irq,void * p)121 static 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->data->has_paging) {
129 mutex_lock(&adis->txrx_lock);
130 if (adis->current_page != 0) {
131 adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
132 adis->tx[1] = 0;
133 spi_write(adis->spi, adis->tx, 2);
134 }
135 }
136
137 ret = spi_sync(adis->spi, &adis->msg);
138 if (ret)
139 dev_err(&adis->spi->dev, "Failed to read data: %d", ret);
140
141
142 if (adis->data->has_paging) {
143 adis->current_page = 0;
144 mutex_unlock(&adis->txrx_lock);
145 }
146
147 iio_push_to_buffers_with_timestamp(indio_dev, adis->buffer,
148 pf->timestamp);
149
150 iio_trigger_notify_done(indio_dev->trig);
151
152 return IRQ_HANDLED;
153 }
154
155 /**
156 * adis_setup_buffer_and_trigger() - Sets up buffer and trigger for the adis device
157 * @adis: The adis device.
158 * @indio_dev: The IIO device.
159 * @trigger_handler: Optional trigger handler, may be NULL.
160 *
161 * Returns 0 on success, a negative error code otherwise.
162 *
163 * This function sets up the buffer and trigger for a adis devices. If
164 * 'trigger_handler' is NULL the default trigger handler will be used. The
165 * default trigger handler will simply read the registers assigned to the
166 * currently active channels.
167 *
168 * adis_cleanup_buffer_and_trigger() should be called to free the resources
169 * allocated by this function.
170 */
adis_setup_buffer_and_trigger(struct adis * adis,struct iio_dev * indio_dev,irqreturn_t (* trigger_handler)(int,void *))171 int adis_setup_buffer_and_trigger(struct adis *adis, struct iio_dev *indio_dev,
172 irqreturn_t (*trigger_handler)(int, void *))
173 {
174 int ret;
175
176 if (!trigger_handler)
177 trigger_handler = adis_trigger_handler;
178
179 ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
180 trigger_handler, NULL);
181 if (ret)
182 return ret;
183
184 if (adis->spi->irq) {
185 ret = adis_probe_trigger(adis, indio_dev);
186 if (ret)
187 goto error_buffer_cleanup;
188 }
189 return 0;
190
191 error_buffer_cleanup:
192 iio_triggered_buffer_cleanup(indio_dev);
193 return ret;
194 }
195 EXPORT_SYMBOL_GPL(adis_setup_buffer_and_trigger);
196
197 /**
198 * adis_cleanup_buffer_and_trigger() - Free buffer and trigger resources
199 * @adis: The adis device.
200 * @indio_dev: The IIO device.
201 *
202 * Frees resources allocated by adis_setup_buffer_and_trigger()
203 */
adis_cleanup_buffer_and_trigger(struct adis * adis,struct iio_dev * indio_dev)204 void adis_cleanup_buffer_and_trigger(struct adis *adis,
205 struct iio_dev *indio_dev)
206 {
207 if (adis->spi->irq)
208 adis_remove_trigger(adis);
209 kfree(adis->buffer);
210 kfree(adis->xfer);
211 iio_triggered_buffer_cleanup(indio_dev);
212 }
213 EXPORT_SYMBOL_GPL(adis_cleanup_buffer_and_trigger);
214