drivers/iio/gyro/itg3200_core.c - linux - Git at Google

 /*
  * itg3200_core.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>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * TODO:
  * - Support digital low pass filter
  * - Support power management
  */

 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/i2c.h>
 #include <linux/gpio.h>
 #include <linux/slab.h>
 #include <linux/stat.h>
 #include <linux/module.h>
 #include <linux/delay.h>

 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/events.h>
 #include <linux/iio/buffer.h>

 #include <linux/iio/gyro/itg3200.h>


 int itg3200_write_reg_8(struct iio_dev *indio_dev,
 		u8 reg_address, u8 val)
 {
 	struct itg3200 *st = iio_priv(indio_dev);

 	return i2c_smbus_write_byte_data(st->i2c, 0x80 | reg_address, val);
 }

 int itg3200_read_reg_8(struct iio_dev *indio_dev,
 		u8 reg_address, u8 *val)
 {
 	struct itg3200 *st = iio_priv(indio_dev);
 	int ret;

 	ret = i2c_smbus_read_byte_data(st->i2c, reg_address);
 	if (ret < 0)
 		return ret;
 	*val = ret;
 	return 0;
 }

 static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 lower_reg_address,
 		int *val)
 {
 	struct itg3200 *st = iio_priv(indio_dev);
 	struct i2c_client *client = st->i2c;
 	int ret;
 	s16 out;

 	struct i2c_msg msg[2] = {
 		{
 			.addr = client->addr,
 			.flags = client->flags,
 			.len = 1,
 			.buf = (char *)&lower_reg_address,
 		},
 		{
 			.addr = client->addr,
 			.flags = client->flags | I2C_M_RD,
 			.len = 2,
 			.buf = (char *)&out,
 		},
 	};

 	lower_reg_address |= 0x80;
 	ret = i2c_transfer(client->adapter, msg, 2);
 	be16_to_cpus(&out);
 	*val = out;

 	return (ret == 2) ? 0 : ret;
 }

 static int itg3200_read_raw(struct iio_dev *indio_dev,
 		const struct iio_chan_spec *chan,
 		int *val, int *val2, long info)
 {
 	int ret = 0;
 	u8 reg;
 	u8 regval;

 	switch (info) {
 	case IIO_CHAN_INFO_RAW:
 		reg = (u8)chan->address;
 		ret = itg3200_read_reg_s16(indio_dev, reg, val);
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		*val = 0;
 		if (chan->type == IIO_TEMP)
 			*val2 = 1000000000/280;
 		else
 			*val2 = 1214142; /* (1 / 14,375) * (PI / 180) */
 		return IIO_VAL_INT_PLUS_NANO;
 	case IIO_CHAN_INFO_OFFSET:
 		/* Only the temperature channel has an offset */
 		*val = 23000;
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &regval);
 		if (ret)
 			return ret;

 		*val = (regval & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;

 		ret = itg3200_read_reg_8(indio_dev,
 					 ITG3200_REG_SAMPLE_RATE_DIV,
 					 &regval);
 		if (ret)
 			return ret;

 		*val /= regval + 1;
 		return IIO_VAL_INT;

 	default:
 		return -EINVAL;
 	}
 }

 static int itg3200_write_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int val,
 			     int val2,
 			     long mask)
 {
 	int ret;
 	u8 t;

 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		if (val == 0 || val2 != 0)
 			return -EINVAL;

 		mutex_lock(&indio_dev->mlock);

 		ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
 		if (ret) {
 			mutex_unlock(&indio_dev->mlock);
 			return ret;
 		}
 		t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;

 		ret = itg3200_write_reg_8(indio_dev,
 					  ITG3200_REG_SAMPLE_RATE_DIV,
 					  t);

 		mutex_unlock(&indio_dev->mlock);
 	return ret;

 	default:
 		return -EINVAL;
 	}
 }

 /*
  * Reset device and internal registers to the power-up-default settings
  * Use the gyro clock as reference, as suggested by the datasheet
  */
 static int itg3200_reset(struct iio_dev *indio_dev)
 {
 	struct itg3200 *st = iio_priv(indio_dev);
 	int ret;

 	dev_dbg(&st->i2c->dev, "reset device");

 	ret = itg3200_write_reg_8(indio_dev,
 			ITG3200_REG_POWER_MANAGEMENT,
 			ITG3200_RESET);
 	if (ret) {
 		dev_err(&st->i2c->dev, "error resetting device");
 		goto error_ret;
 	}

 	/* Wait for PLL (1ms according to datasheet) */
 	udelay(1500);

 	ret = itg3200_write_reg_8(indio_dev,
 			ITG3200_REG_IRQ_CONFIG,
 			ITG3200_IRQ_ACTIVE_HIGH |
 			ITG3200_IRQ_PUSH_PULL |
 			ITG3200_IRQ_LATCH_50US_PULSE |
 			ITG3200_IRQ_LATCH_CLEAR_ANY);

 	if (ret)
 		dev_err(&st->i2c->dev, "error init device");

 error_ret:
 	return ret;
 }

 /* itg3200_enable_full_scale() - Disables the digital low pass filter */
 static int itg3200_enable_full_scale(struct iio_dev *indio_dev)
 {
 	u8 val;
 	int ret;

 	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
 	if (ret)
 		goto err_ret;

 	val |= ITG3200_DLPF_FS_SEL_2000;
 	return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val);

 err_ret:
 	return ret;
 }

 static int itg3200_initial_setup(struct iio_dev *indio_dev)
 {
 	struct itg3200 *st = iio_priv(indio_dev);
 	int ret;
 	u8 val;

 	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val);
 	if (ret)
 		goto err_ret;

 	if (((val >> 1) & 0x3f) != 0x34) {
 		dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val);
 		ret = -ENXIO;
 		goto err_ret;
 	}

 	ret = itg3200_reset(indio_dev);
 	if (ret)
 		goto err_ret;

 	ret = itg3200_enable_full_scale(indio_dev);
 err_ret:
 	return ret;
 }

 #define ITG3200_ST						\
 	{ .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE }

 #define ITG3200_GYRO_CHAN(_mod) { \
 	.type = IIO_ANGL_VEL, \
 	.modified = 1, \
 	.channel2 = IIO_MOD_ ## _mod, \
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
 	.address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \
 	.scan_index = ITG3200_SCAN_GYRO_ ## _mod, \
 	.scan_type = ITG3200_ST, \
 }

 static const struct iio_chan_spec itg3200_channels[] = {
 	{
 		.type = IIO_TEMP,
 		.channel2 = IIO_NO_MOD,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
 		BIT(IIO_CHAN_INFO_SCALE),
 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 		.address = ITG3200_REG_TEMP_OUT_H,
 		.scan_index = ITG3200_SCAN_TEMP,
 		.scan_type = ITG3200_ST,
 	},
 	ITG3200_GYRO_CHAN(X),
 	ITG3200_GYRO_CHAN(Y),
 	ITG3200_GYRO_CHAN(Z),
 	IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS),
 };

 static const struct iio_info itg3200_info = {
 	.read_raw = &itg3200_read_raw,
 	.write_raw = &itg3200_write_raw,
 	.driver_module = THIS_MODULE,
 };

 static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 };

 static int itg3200_probe(struct i2c_client *client,
 		const struct i2c_device_id *id)
 {
 	int ret;
 	struct itg3200 *st;
 	struct iio_dev *indio_dev;

 	dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq);

 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
 	if (!indio_dev)
 		return -ENOMEM;

 	st = iio_priv(indio_dev);

 	i2c_set_clientdata(client, indio_dev);
 	st->i2c = client;

 	indio_dev->dev.parent = &client->dev;
 	indio_dev->name = client->dev.driver->name;
 	indio_dev->channels = itg3200_channels;
 	indio_dev->num_channels = ARRAY_SIZE(itg3200_channels);
 	indio_dev->available_scan_masks = itg3200_available_scan_masks;
 	indio_dev->info = &itg3200_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;

 	ret = itg3200_buffer_configure(indio_dev);
 	if (ret)
 		return ret;

 	if (client->irq) {
 		ret = itg3200_probe_trigger(indio_dev);
 		if (ret)
 			goto error_unconfigure_buffer;
 	}

 	ret = itg3200_initial_setup(indio_dev);
 	if (ret)
 		goto error_remove_trigger;

 	ret = iio_device_register(indio_dev);
 	if (ret)
 		goto error_remove_trigger;

 	return 0;

 error_remove_trigger:
 	if (client->irq)
 		itg3200_remove_trigger(indio_dev);
 error_unconfigure_buffer:
 	itg3200_buffer_unconfigure(indio_dev);
 	return ret;
 }

 static int itg3200_remove(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);

 	iio_device_unregister(indio_dev);

 	if (client->irq)
 		itg3200_remove_trigger(indio_dev);

 	itg3200_buffer_unconfigure(indio_dev);

 	return 0;
 }

 static const struct i2c_device_id itg3200_id[] = {
 	{ "itg3200", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, itg3200_id);

 static struct i2c_driver itg3200_driver = {
 	.driver = {
 		.owner  = THIS_MODULE,
 		.name	= "itg3200",
 	},
 	.id_table	= itg3200_id,
 	.probe		= itg3200_probe,
 	.remove		= itg3200_remove,
 };

 module_i2c_driver(itg3200_driver);

 MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>");
 MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver");
 MODULE_LICENSE("GPL v2");
	/*
	* itg3200_core.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>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* TODO:
	* - Support digital low pass filter
	* - Support power management
	*/

	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/i2c.h>
	#include <linux/gpio.h>
	#include <linux/slab.h>
	#include <linux/stat.h>
	#include <linux/module.h>
	#include <linux/delay.h>

	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/events.h>
	#include <linux/iio/buffer.h>

	#include <linux/iio/gyro/itg3200.h>


	int itg3200_write_reg_8(struct iio_dev *indio_dev,
	u8 reg_address, u8 val)
	{
	struct itg3200 *st = iio_priv(indio_dev);

	return i2c_smbus_write_byte_data(st->i2c, 0x80 \| reg_address, val);
	}

	int itg3200_read_reg_8(struct iio_dev *indio_dev,
	u8 reg_address, u8 *val)
	{
	struct itg3200 *st = iio_priv(indio_dev);
	int ret;

	ret = i2c_smbus_read_byte_data(st->i2c, reg_address);
	if (ret < 0)
	return ret;
	*val = ret;
	return 0;
	}

	static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 lower_reg_address,
	int *val)
	{
	struct itg3200 *st = iio_priv(indio_dev);
	struct i2c_client *client = st->i2c;
	int ret;
	s16 out;

	struct i2c_msg msg[2] = {
	{
	.addr = client->addr,
	.flags = client->flags,
	.len = 1,
	.buf = (char *)&lower_reg_address,
	},
	{
	.addr = client->addr,
	.flags = client->flags \| I2C_M_RD,
	.len = 2,
	.buf = (char *)&out,
	},
	};

	lower_reg_address \|= 0x80;
	ret = i2c_transfer(client->adapter, msg, 2);
	be16_to_cpus(&out);
	*val = out;

	return (ret == 2) ? 0 : ret;
	}

	static int itg3200_read_raw(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan,
	int val, int val2, long info)
	{
	int ret = 0;
	u8 reg;
	u8 regval;

	switch (info) {
	case IIO_CHAN_INFO_RAW:
	reg = (u8)chan->address;
	ret = itg3200_read_reg_s16(indio_dev, reg, val);
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
	*val = 0;
	if (chan->type == IIO_TEMP)
	*val2 = 1000000000/280;
	else
	val2 = 1214142; / (1 / 14,375) * (PI / 180) */
	return IIO_VAL_INT_PLUS_NANO;
	case IIO_CHAN_INFO_OFFSET:
	/* Only the temperature channel has an offset */
	*val = 23000;
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SAMP_FREQ:
	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &regval);
	if (ret)
	return ret;

	*val = (regval & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;

	ret = itg3200_read_reg_8(indio_dev,
	ITG3200_REG_SAMPLE_RATE_DIV,
	&regval);
	if (ret)
	return ret;

	*val /= regval + 1;
	return IIO_VAL_INT;

	default:
	return -EINVAL;
	}
	}

	static int itg3200_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val,
	int val2,
	long mask)
	{
	int ret;
	u8 t;

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
	if (val == 0 \|\| val2 != 0)
	return -EINVAL;

	mutex_lock(&indio_dev->mlock);

	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
	if (ret) {
	mutex_unlock(&indio_dev->mlock);
	return ret;
	}
	t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;

	ret = itg3200_write_reg_8(indio_dev,
	ITG3200_REG_SAMPLE_RATE_DIV,
	t);

	mutex_unlock(&indio_dev->mlock);
	return ret;

	default:
	return -EINVAL;
	}
	}

	/*
	* Reset device and internal registers to the power-up-default settings
	* Use the gyro clock as reference, as suggested by the datasheet
	*/
	static int itg3200_reset(struct iio_dev *indio_dev)
	{
	struct itg3200 *st = iio_priv(indio_dev);
	int ret;

	dev_dbg(&st->i2c->dev, "reset device");

	ret = itg3200_write_reg_8(indio_dev,
	ITG3200_REG_POWER_MANAGEMENT,
	ITG3200_RESET);
	if (ret) {
	dev_err(&st->i2c->dev, "error resetting device");
	goto error_ret;
	}

	/* Wait for PLL (1ms according to datasheet) */
	udelay(1500);

	ret = itg3200_write_reg_8(indio_dev,
	ITG3200_REG_IRQ_CONFIG,
	ITG3200_IRQ_ACTIVE_HIGH \|
	ITG3200_IRQ_PUSH_PULL \|
	ITG3200_IRQ_LATCH_50US_PULSE \|
	ITG3200_IRQ_LATCH_CLEAR_ANY);

	if (ret)
	dev_err(&st->i2c->dev, "error init device");

	error_ret:
	return ret;
	}

	/* itg3200_enable_full_scale() - Disables the digital low pass filter */
	static int itg3200_enable_full_scale(struct iio_dev *indio_dev)
	{
	u8 val;
	int ret;

	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
	if (ret)
	goto err_ret;

	val \|= ITG3200_DLPF_FS_SEL_2000;
	return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val);

	err_ret:
	return ret;
	}

	static int itg3200_initial_setup(struct iio_dev *indio_dev)
	{
	struct itg3200 *st = iio_priv(indio_dev);
	int ret;
	u8 val;

	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val);
	if (ret)
	goto err_ret;

	if (((val >> 1) & 0x3f) != 0x34) {
	dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val);
	ret = -ENXIO;
	goto err_ret;
	}

	ret = itg3200_reset(indio_dev);
	if (ret)
	goto err_ret;

	ret = itg3200_enable_full_scale(indio_dev);
	err_ret:
	return ret;
	}

	#define ITG3200_ST \
	{ .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE }

	#define ITG3200_GYRO_CHAN(_mod) { \
	.type = IIO_ANGL_VEL, \
	.modified = 1, \
	.channel2 = IIO_MOD_ ## _mod, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
	.address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \
	.scan_index = ITG3200_SCAN_GYRO_ ## _mod, \
	.scan_type = ITG3200_ST, \
	}

	static const struct iio_chan_spec itg3200_channels[] = {
	{
	.type = IIO_TEMP,
	.channel2 = IIO_NO_MOD,
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) \|
	BIT(IIO_CHAN_INFO_SCALE),
	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
	.address = ITG3200_REG_TEMP_OUT_H,
	.scan_index = ITG3200_SCAN_TEMP,
	.scan_type = ITG3200_ST,
	},
	ITG3200_GYRO_CHAN(X),
	ITG3200_GYRO_CHAN(Y),
	ITG3200_GYRO_CHAN(Z),
	IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS),
	};

	static const struct iio_info itg3200_info = {
	.read_raw = &itg3200_read_raw,
	.write_raw = &itg3200_write_raw,
	.driver_module = THIS_MODULE,
	};

	static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 };

	static int itg3200_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	int ret;
	struct itg3200 *st;
	struct iio_dev *indio_dev;

	dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq);

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
	if (!indio_dev)
	return -ENOMEM;

	st = iio_priv(indio_dev);

	i2c_set_clientdata(client, indio_dev);
	st->i2c = client;

	indio_dev->dev.parent = &client->dev;
	indio_dev->name = client->dev.driver->name;
	indio_dev->channels = itg3200_channels;
	indio_dev->num_channels = ARRAY_SIZE(itg3200_channels);
	indio_dev->available_scan_masks = itg3200_available_scan_masks;
	indio_dev->info = &itg3200_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = itg3200_buffer_configure(indio_dev);
	if (ret)
	return ret;

	if (client->irq) {
	ret = itg3200_probe_trigger(indio_dev);
	if (ret)
	goto error_unconfigure_buffer;
	}

	ret = itg3200_initial_setup(indio_dev);
	if (ret)
	goto error_remove_trigger;

	ret = iio_device_register(indio_dev);
	if (ret)
	goto error_remove_trigger;

	return 0;

	error_remove_trigger:
	if (client->irq)
	itg3200_remove_trigger(indio_dev);
	error_unconfigure_buffer:
	itg3200_buffer_unconfigure(indio_dev);
	return ret;
	}

	static int itg3200_remove(struct i2c_client *client)
	{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	iio_device_unregister(indio_dev);

	if (client->irq)
	itg3200_remove_trigger(indio_dev);

	itg3200_buffer_unconfigure(indio_dev);

	return 0;
	}

	static const struct i2c_device_id itg3200_id[] = {
	{ "itg3200", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, itg3200_id);

	static struct i2c_driver itg3200_driver = {
	.driver = {
	.owner = THIS_MODULE,
	.name = "itg3200",
	},
	.id_table = itg3200_id,
	.probe = itg3200_probe,
	.remove = itg3200_remove,
	};

	module_i2c_driver(itg3200_driver);

	MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>");
	MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver");
	MODULE_LICENSE("GPL v2");