xref: /linux/drivers/iio/imu/adis_buffer.c (revision a36e9f5cfe9eb3a1dce8769c7058251c42705357)
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 
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, 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 	if (adis->data->burst_max_speed_hz)
55 		adis->xfer[0].speed_hz = adis->data->burst_max_speed_hz;
56 	adis->xfer[1].rx_buf = adis->buffer;
57 	adis->xfer[1].bits_per_word = 8;
58 	adis->xfer[1].len = burst_length;
59 	if (adis->data->burst_max_speed_hz)
60 		adis->xfer[1].speed_hz = adis->data->burst_max_speed_hz;
61 
62 	spi_message_init(&adis->msg);
63 	spi_message_add_tail(&adis->xfer[0], &adis->msg);
64 	spi_message_add_tail(&adis->xfer[1], &adis->msg);
65 
66 	return 0;
67 }
68 
69 int adis_update_scan_mode(struct iio_dev *indio_dev,
70 			  const unsigned long *scan_mask)
71 {
72 	struct adis *adis = iio_device_get_drvdata(indio_dev);
73 	const struct iio_chan_spec *chan;
74 	unsigned int scan_count;
75 	unsigned int i, j;
76 	__be16 *tx, *rx;
77 
78 	kfree(adis->xfer);
79 	kfree(adis->buffer);
80 
81 	if (adis->data->burst_len)
82 		return adis_update_scan_mode_burst(indio_dev, scan_mask);
83 
84 	scan_count = indio_dev->scan_bytes / 2;
85 
86 	adis->xfer = kcalloc(scan_count + 1, sizeof(*adis->xfer), GFP_KERNEL);
87 	if (!adis->xfer)
88 		return -ENOMEM;
89 
90 	adis->buffer = kcalloc(indio_dev->scan_bytes, 2, GFP_KERNEL);
91 	if (!adis->buffer) {
92 		kfree(adis->xfer);
93 		adis->xfer = NULL;
94 		return -ENOMEM;
95 	}
96 
97 	rx = adis->buffer;
98 	tx = rx + scan_count;
99 
100 	spi_message_init(&adis->msg);
101 
102 	for (j = 0; j <= scan_count; j++) {
103 		adis->xfer[j].bits_per_word = 8;
104 		if (j != scan_count)
105 			adis->xfer[j].cs_change = 1;
106 		adis->xfer[j].len = 2;
107 		adis->xfer[j].delay.value = adis->data->read_delay;
108 		adis->xfer[j].delay.unit = SPI_DELAY_UNIT_USECS;
109 		if (j < scan_count)
110 			adis->xfer[j].tx_buf = &tx[j];
111 		if (j >= 1)
112 			adis->xfer[j].rx_buf = &rx[j - 1];
113 		spi_message_add_tail(&adis->xfer[j], &adis->msg);
114 	}
115 
116 	chan = indio_dev->channels;
117 	for (i = 0; i < indio_dev->num_channels; i++, chan++) {
118 		if (!test_bit(chan->scan_index, scan_mask))
119 			continue;
120 		if (chan->scan_type.storagebits == 32)
121 			*tx++ = cpu_to_be16((chan->address + 2) << 8);
122 		*tx++ = cpu_to_be16(chan->address << 8);
123 	}
124 
125 	return 0;
126 }
127 EXPORT_SYMBOL_NS_GPL(adis_update_scan_mode, IIO_ADISLIB);
128 
129 static int adis_paging_trigger_handler(struct adis *adis)
130 {
131 	int ret;
132 
133 	guard(mutex)(&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 		ret = spi_write(adis->spi, adis->tx, 2);
138 		if (ret) {
139 			dev_err(&adis->spi->dev, "Failed to change device page: %d\n", ret);
140 			return ret;
141 		}
142 
143 		adis->current_page = 0;
144 	}
145 
146 	return spi_sync(adis->spi, &adis->msg);
147 }
148 
149 static irqreturn_t adis_trigger_handler(int irq, void *p)
150 {
151 	struct iio_poll_func *pf = p;
152 	struct iio_dev *indio_dev = pf->indio_dev;
153 	struct adis *adis = iio_device_get_drvdata(indio_dev);
154 	int ret;
155 
156 	if (adis->data->has_paging)
157 		ret = adis_paging_trigger_handler(adis);
158 	else
159 		ret = spi_sync(adis->spi, &adis->msg);
160 	if (ret) {
161 		dev_err(&adis->spi->dev, "Failed to read data: %d", ret);
162 		goto irq_done;
163 	}
164 
165 	iio_push_to_buffers_with_timestamp(indio_dev, adis->buffer,
166 					   pf->timestamp);
167 
168 irq_done:
169 	iio_trigger_notify_done(indio_dev->trig);
170 
171 	return IRQ_HANDLED;
172 }
173 
174 static void adis_buffer_cleanup(void *arg)
175 {
176 	struct adis *adis = arg;
177 
178 	kfree(adis->buffer);
179 	kfree(adis->xfer);
180 }
181 
182 /**
183  * devm_adis_setup_buffer_and_trigger_with_attrs() - Sets up buffer and trigger
184  * for the managed adis device with buffer attributes.
185  * @adis: The adis device
186  * @indio_dev: The IIO device
187  * @trigger_handler: Trigger handler: should handle the buffer readings.
188  * @ops: Optional buffer setup functions, may be NULL.
189  * @buffer_attrs: Extra buffer attributes.
190  *
191  * Returns 0 on success, a negative error code otherwise.
192  *
193  * This function sets up the buffer (with buffer setup functions and extra
194  * buffer attributes) and trigger for a adis devices with buffer attributes.
195  */
196 int
197 devm_adis_setup_buffer_and_trigger_with_attrs(struct adis *adis, struct iio_dev *indio_dev,
198 					      irq_handler_t trigger_handler,
199 					      const struct iio_buffer_setup_ops *ops,
200 					      const struct iio_dev_attr **buffer_attrs)
201 {
202 	int ret;
203 
204 	if (!trigger_handler)
205 		trigger_handler = adis_trigger_handler;
206 
207 	ret = devm_iio_triggered_buffer_setup_ext(&adis->spi->dev, indio_dev,
208 						  &iio_pollfunc_store_time,
209 						  trigger_handler,
210 						  IIO_BUFFER_DIRECTION_IN,
211 						  ops,
212 						  buffer_attrs);
213 	if (ret)
214 		return ret;
215 
216 	if (adis->spi->irq) {
217 		ret = devm_adis_probe_trigger(adis, indio_dev);
218 		if (ret)
219 			return ret;
220 	}
221 
222 	return devm_add_action_or_reset(&adis->spi->dev, adis_buffer_cleanup,
223 					adis);
224 }
225 EXPORT_SYMBOL_NS_GPL(devm_adis_setup_buffer_and_trigger_with_attrs, IIO_ADISLIB);
226