drivers/iio/gyro/itg3200_buffer.c

Source file repositories/reference/linux-study-clean/drivers/iio/gyro/itg3200_buffer.c

File Facts

System
Linux kernel
Corpus path
drivers/iio/gyro/itg3200_buffer.c
Extension
.c
Size
3556 bytes
Lines
154
Domain
Driver Families
Bucket
drivers/iio
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * itg3200_buffer.c -- support InvenSense ITG3200
 *                     Digital 3-Axis Gyroscope driver
 *
 * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de>
 * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
 * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de>
 */

#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>

#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/gyro/itg3200.h>


static int itg3200_read_all_channels(struct i2c_client *i2c, __be16 *buf)
{
	u8 tx = 0x80 | ITG3200_REG_TEMP_OUT_H;
	struct i2c_msg msg[2] = {
		{
			.addr = i2c->addr,
			.flags = i2c->flags,
			.len = 1,
			.buf = &tx,
		},
		{
			.addr = i2c->addr,
			.flags = i2c->flags | I2C_M_RD,
			.len = ITG3200_SCAN_ELEMENTS * sizeof(s16),
			.buf = (char *)buf,
		},
	};

	return i2c_transfer(i2c->adapter, msg, 2);
}

static irqreturn_t itg3200_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct itg3200 *st = iio_priv(indio_dev);
	/*
	 * Ensure correct alignment and padding including for the
	 * timestamp that may be inserted.
	 */
	struct {
		__be16 buf[ITG3200_SCAN_ELEMENTS];
		aligned_s64 ts;
	} scan;

	int ret = itg3200_read_all_channels(st->i2c, scan.buf);
	if (ret < 0)
		goto error_ret;

	iio_push_to_buffers_with_timestamp(indio_dev, &scan, pf->timestamp);

error_ret:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

int itg3200_buffer_configure(struct iio_dev *indio_dev)
{
	return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
		itg3200_trigger_handler, NULL);
}

void itg3200_buffer_unconfigure(struct iio_dev *indio_dev)
{
	iio_triggered_buffer_cleanup(indio_dev);
}


static int itg3200_data_rdy_trigger_set_state(struct iio_trigger *trig,
		bool state)
{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	int ret;
	u8 msc;

	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, &msc);
	if (ret)

Annotation

Implementation Notes