adis_buffer.c

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