drivers/iio/accel/mma7455_core.c - linux - Git at Google

 /*
  * IIO accel core driver for Freescale MMA7455L 3-axis 10-bit accelerometer
  * Copyright 2015 Joachim Eastwood <manabian@gmail.com>
  *
  * 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.
  *
  * UNSUPPORTED hardware features:
  *  - 8-bit mode with different scales
  *  - INT1/INT2 interrupts
  *  - Offset calibration
  *  - Events
  */

 #include <linux/delay.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.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/module.h>
 #include <linux/regmap.h>

 #include "mma7455.h"

 #define MMA7455_REG_XOUTL		0x00
 #define MMA7455_REG_XOUTH		0x01
 #define MMA7455_REG_YOUTL		0x02
 #define MMA7455_REG_YOUTH		0x03
 #define MMA7455_REG_ZOUTL		0x04
 #define MMA7455_REG_ZOUTH		0x05
 #define MMA7455_REG_STATUS		0x09
 #define  MMA7455_STATUS_DRDY		BIT(0)
 #define MMA7455_REG_WHOAMI		0x0f
 #define  MMA7455_WHOAMI_ID		0x55
 #define MMA7455_REG_MCTL		0x16
 #define  MMA7455_MCTL_MODE_STANDBY	0x00
 #define  MMA7455_MCTL_MODE_MEASURE	0x01
 #define MMA7455_REG_CTL1		0x18
 #define  MMA7455_CTL1_DFBW_MASK		BIT(7)
 #define  MMA7455_CTL1_DFBW_125HZ	BIT(7)
 #define  MMA7455_CTL1_DFBW_62_5HZ	0
 #define MMA7455_REG_TW			0x1e

 /*
  * When MMA7455 is used in 10-bit it has a fullscale of -8g
  * corresponding to raw value -512. The userspace interface
  * uses m/s^2 and we declare micro units.
  * So scale factor is given by:
  *       g * 8 * 1e6 / 512 = 153228.90625, with g = 9.80665
  */
 #define MMA7455_10BIT_SCALE	153229

 struct mma7455_data {
 	struct regmap *regmap;
 };

 static int mma7455_drdy(struct mma7455_data *mma7455)
 {
 	struct device *dev = regmap_get_device(mma7455->regmap);
 	unsigned int reg;
 	int tries = 3;
 	int ret;

 	while (tries-- > 0) {
 		ret = regmap_read(mma7455->regmap, MMA7455_REG_STATUS, &reg);
 		if (ret)
 			return ret;

 		if (reg & MMA7455_STATUS_DRDY)
 			return 0;

 		msleep(20);
 	}

 	dev_warn(dev, "data not ready\n");

 	return -EIO;
 }

 static irqreturn_t mma7455_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct mma7455_data *mma7455 = iio_priv(indio_dev);
 	u8 buf[16]; /* 3 x 16-bit channels + padding + ts */
 	int ret;

 	ret = mma7455_drdy(mma7455);
 	if (ret)
 		goto done;

 	ret = regmap_bulk_read(mma7455->regmap, MMA7455_REG_XOUTL, buf,
 			       sizeof(__le16) * 3);
 	if (ret)
 		goto done;

 	iio_push_to_buffers_with_timestamp(indio_dev, buf,
 					   iio_get_time_ns(indio_dev));

 done:
 	iio_trigger_notify_done(indio_dev->trig);

 	return IRQ_HANDLED;
 }

 static int mma7455_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int *val, int *val2, long mask)
 {
 	struct mma7455_data *mma7455 = iio_priv(indio_dev);
 	unsigned int reg;
 	__le16 data;
 	int ret;

 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		if (iio_buffer_enabled(indio_dev))
 			return -EBUSY;

 		ret = mma7455_drdy(mma7455);
 		if (ret)
 			return ret;

 		ret = regmap_bulk_read(mma7455->regmap, chan->address, &data,
 				       sizeof(data));
 		if (ret)
 			return ret;

 		*val = sign_extend32(le16_to_cpu(data), 9);

 		return IIO_VAL_INT;

 	case IIO_CHAN_INFO_SCALE:
 		*val = 0;
 		*val2 = MMA7455_10BIT_SCALE;

 		return IIO_VAL_INT_PLUS_MICRO;

 	case IIO_CHAN_INFO_SAMP_FREQ:
 		ret = regmap_read(mma7455->regmap, MMA7455_REG_CTL1, &reg);
 		if (ret)
 			return ret;

 		if (reg & MMA7455_CTL1_DFBW_MASK)
 			*val = 250;
 		else
 			*val = 125;

 		return IIO_VAL_INT;
 	}

 	return -EINVAL;
 }

 static int mma7455_write_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int val, int val2, long mask)
 {
 	struct mma7455_data *mma7455 = iio_priv(indio_dev);
 	int i;

 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		if (val == 250 && val2 == 0)
 			i = MMA7455_CTL1_DFBW_125HZ;
 		else if (val == 125 && val2 == 0)
 			i = MMA7455_CTL1_DFBW_62_5HZ;
 		else
 			return -EINVAL;

 		return regmap_update_bits(mma7455->regmap, MMA7455_REG_CTL1,
 					  MMA7455_CTL1_DFBW_MASK, i);

 	case IIO_CHAN_INFO_SCALE:
 		/* In 10-bit mode there is only one scale available */
 		if (val == 0 && val2 == MMA7455_10BIT_SCALE)
 			return 0;
 		break;
 	}

 	return -EINVAL;
 }

 static IIO_CONST_ATTR(sampling_frequency_available, "125 250");

 static struct attribute *mma7455_attributes[] = {
 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group mma7455_group = {
 	.attrs = mma7455_attributes,
 };

 static const struct iio_info mma7455_info = {
 	.attrs = &mma7455_group,
 	.read_raw = mma7455_read_raw,
 	.write_raw = mma7455_write_raw,
 };

 #define MMA7455_CHANNEL(axis, idx) { \
 	.type = IIO_ACCEL, \
 	.modified = 1, \
 	.address = MMA7455_REG_##axis##OUTL,\
 	.channel2 = IIO_MOD_##axis, \
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
 				    BIT(IIO_CHAN_INFO_SCALE), \
 	.scan_index = idx, \
 	.scan_type = { \
 		.sign = 's', \
 		.realbits = 10, \
 		.storagebits = 16, \
 		.endianness = IIO_LE, \
 	}, \
 }

 static const struct iio_chan_spec mma7455_channels[] = {
 	MMA7455_CHANNEL(X, 0),
 	MMA7455_CHANNEL(Y, 1),
 	MMA7455_CHANNEL(Z, 2),
 	IIO_CHAN_SOFT_TIMESTAMP(3),
 };

 static const unsigned long mma7455_scan_masks[] = {0x7, 0};

 const struct regmap_config mma7455_core_regmap = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.max_register = MMA7455_REG_TW,
 };
 EXPORT_SYMBOL_GPL(mma7455_core_regmap);

 int mma7455_core_probe(struct device *dev, struct regmap *regmap,
 		       const char *name)
 {
 	struct mma7455_data *mma7455;
 	struct iio_dev *indio_dev;
 	unsigned int reg;
 	int ret;

 	ret = regmap_read(regmap, MMA7455_REG_WHOAMI, &reg);
 	if (ret) {
 		dev_err(dev, "unable to read reg\n");
 		return ret;
 	}

 	if (reg != MMA7455_WHOAMI_ID) {
 		dev_err(dev, "device id mismatch\n");
 		return -ENODEV;
 	}

 	indio_dev = devm_iio_device_alloc(dev, sizeof(*mma7455));
 	if (!indio_dev)
 		return -ENOMEM;

 	dev_set_drvdata(dev, indio_dev);
 	mma7455 = iio_priv(indio_dev);
 	mma7455->regmap = regmap;

 	indio_dev->info = &mma7455_info;
 	indio_dev->name = name;
 	indio_dev->dev.parent = dev;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = mma7455_channels;
 	indio_dev->num_channels = ARRAY_SIZE(mma7455_channels);
 	indio_dev->available_scan_masks = mma7455_scan_masks;

 	regmap_write(mma7455->regmap, MMA7455_REG_MCTL,
 		     MMA7455_MCTL_MODE_MEASURE);

 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 					 mma7455_trigger_handler, NULL);
 	if (ret) {
 		dev_err(dev, "unable to setup triggered buffer\n");
 		return ret;
 	}

 	ret = iio_device_register(indio_dev);
 	if (ret) {
 		dev_err(dev, "unable to register device\n");
 		iio_triggered_buffer_cleanup(indio_dev);
 		return ret;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(mma7455_core_probe);

 int mma7455_core_remove(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct mma7455_data *mma7455 = iio_priv(indio_dev);

 	iio_device_unregister(indio_dev);
 	iio_triggered_buffer_cleanup(indio_dev);

 	regmap_write(mma7455->regmap, MMA7455_REG_MCTL,
 		     MMA7455_MCTL_MODE_STANDBY);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(mma7455_core_remove);

 MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
 MODULE_DESCRIPTION("Freescale MMA7455L core accelerometer driver");
 MODULE_LICENSE("GPL v2");
	/*
	* IIO accel core driver for Freescale MMA7455L 3-axis 10-bit accelerometer
	* Copyright 2015 Joachim Eastwood <manabian@gmail.com>
	*
	* 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.
	*
	* UNSUPPORTED hardware features:
	* - 8-bit mode with different scales
	* - INT1/INT2 interrupts
	* - Offset calibration
	* - Events
	*/

	#include <linux/delay.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.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/module.h>
	#include <linux/regmap.h>

	#include "mma7455.h"

	#define MMA7455_REG_XOUTL 0x00
	#define MMA7455_REG_XOUTH 0x01
	#define MMA7455_REG_YOUTL 0x02
	#define MMA7455_REG_YOUTH 0x03
	#define MMA7455_REG_ZOUTL 0x04
	#define MMA7455_REG_ZOUTH 0x05
	#define MMA7455_REG_STATUS 0x09
	#define MMA7455_STATUS_DRDY BIT(0)
	#define MMA7455_REG_WHOAMI 0x0f
	#define MMA7455_WHOAMI_ID 0x55
	#define MMA7455_REG_MCTL 0x16
	#define MMA7455_MCTL_MODE_STANDBY 0x00
	#define MMA7455_MCTL_MODE_MEASURE 0x01
	#define MMA7455_REG_CTL1 0x18
	#define MMA7455_CTL1_DFBW_MASK BIT(7)
	#define MMA7455_CTL1_DFBW_125HZ BIT(7)
	#define MMA7455_CTL1_DFBW_62_5HZ 0
	#define MMA7455_REG_TW 0x1e

	/*
	* When MMA7455 is used in 10-bit it has a fullscale of -8g
	* corresponding to raw value -512. The userspace interface
	* uses m/s^2 and we declare micro units.
	* So scale factor is given by:
	* g * 8 * 1e6 / 512 = 153228.90625, with g = 9.80665
	*/
	#define MMA7455_10BIT_SCALE 153229

	struct mma7455_data {
	struct regmap *regmap;
	};

	static int mma7455_drdy(struct mma7455_data *mma7455)
	{
	struct device *dev = regmap_get_device(mma7455->regmap);
	unsigned int reg;
	int tries = 3;
	int ret;

	while (tries-- > 0) {
	ret = regmap_read(mma7455->regmap, MMA7455_REG_STATUS, &reg);
	if (ret)
	return ret;

	if (reg & MMA7455_STATUS_DRDY)
	return 0;

	msleep(20);
	}

	dev_warn(dev, "data not ready\n");

	return -EIO;
	}

	static irqreturn_t mma7455_trigger_handler(int irq, void *p)
	{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct mma7455_data *mma7455 = iio_priv(indio_dev);
	u8 buf[16]; /* 3 x 16-bit channels + padding + ts */
	int ret;

	ret = mma7455_drdy(mma7455);
	if (ret)
	goto done;

	ret = regmap_bulk_read(mma7455->regmap, MMA7455_REG_XOUTL, buf,
	sizeof(__le16) * 3);
	if (ret)
	goto done;

	iio_push_to_buffers_with_timestamp(indio_dev, buf,
	iio_get_time_ns(indio_dev));

	done:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
	}

	static int mma7455_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct mma7455_data *mma7455 = iio_priv(indio_dev);
	unsigned int reg;
	__le16 data;
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	if (iio_buffer_enabled(indio_dev))
	return -EBUSY;

	ret = mma7455_drdy(mma7455);
	if (ret)
	return ret;

	ret = regmap_bulk_read(mma7455->regmap, chan->address, &data,
	sizeof(data));
	if (ret)
	return ret;

	*val = sign_extend32(le16_to_cpu(data), 9);

	return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:
	*val = 0;
	*val2 = MMA7455_10BIT_SCALE;

	return IIO_VAL_INT_PLUS_MICRO;

	case IIO_CHAN_INFO_SAMP_FREQ:
	ret = regmap_read(mma7455->regmap, MMA7455_REG_CTL1, &reg);
	if (ret)
	return ret;

	if (reg & MMA7455_CTL1_DFBW_MASK)
	*val = 250;
	else
	*val = 125;

	return IIO_VAL_INT;
	}

	return -EINVAL;
	}

	static int mma7455_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct mma7455_data *mma7455 = iio_priv(indio_dev);
	int i;

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
	if (val == 250 && val2 == 0)
	i = MMA7455_CTL1_DFBW_125HZ;
	else if (val == 125 && val2 == 0)
	i = MMA7455_CTL1_DFBW_62_5HZ;
	else
	return -EINVAL;

	return regmap_update_bits(mma7455->regmap, MMA7455_REG_CTL1,
	MMA7455_CTL1_DFBW_MASK, i);

	case IIO_CHAN_INFO_SCALE:
	/* In 10-bit mode there is only one scale available */
	if (val == 0 && val2 == MMA7455_10BIT_SCALE)
	return 0;
	break;
	}

	return -EINVAL;
	}

	static IIO_CONST_ATTR(sampling_frequency_available, "125 250");

	static struct attribute *mma7455_attributes[] = {
	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
	NULL
	};

	static const struct attribute_group mma7455_group = {
	.attrs = mma7455_attributes,
	};

	static const struct iio_info mma7455_info = {
	.attrs = &mma7455_group,
	.read_raw = mma7455_read_raw,
	.write_raw = mma7455_write_raw,
	};

	#define MMA7455_CHANNEL(axis, idx) { \
	.type = IIO_ACCEL, \
	.modified = 1, \
	.address = MMA7455_REG_##axis##OUTL,\
	.channel2 = IIO_MOD_##axis, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) \| \
	BIT(IIO_CHAN_INFO_SCALE), \
	.scan_index = idx, \
	.scan_type = { \
	.sign = 's', \
	.realbits = 10, \
	.storagebits = 16, \
	.endianness = IIO_LE, \
	}, \
	}

	static const struct iio_chan_spec mma7455_channels[] = {
	MMA7455_CHANNEL(X, 0),
	MMA7455_CHANNEL(Y, 1),
	MMA7455_CHANNEL(Z, 2),
	IIO_CHAN_SOFT_TIMESTAMP(3),
	};

	static const unsigned long mma7455_scan_masks[] = {0x7, 0};

	const struct regmap_config mma7455_core_regmap = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = MMA7455_REG_TW,
	};
	EXPORT_SYMBOL_GPL(mma7455_core_regmap);

	int mma7455_core_probe(struct device dev, struct regmap regmap,
	const char *name)
	{
	struct mma7455_data *mma7455;
	struct iio_dev *indio_dev;
	unsigned int reg;
	int ret;

	ret = regmap_read(regmap, MMA7455_REG_WHOAMI, &reg);
	if (ret) {
	dev_err(dev, "unable to read reg\n");
	return ret;
	}

	if (reg != MMA7455_WHOAMI_ID) {
	dev_err(dev, "device id mismatch\n");
	return -ENODEV;
	}

	indio_dev = devm_iio_device_alloc(dev, sizeof(*mma7455));
	if (!indio_dev)
	return -ENOMEM;

	dev_set_drvdata(dev, indio_dev);
	mma7455 = iio_priv(indio_dev);
	mma7455->regmap = regmap;

	indio_dev->info = &mma7455_info;
	indio_dev->name = name;
	indio_dev->dev.parent = dev;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = mma7455_channels;
	indio_dev->num_channels = ARRAY_SIZE(mma7455_channels);
	indio_dev->available_scan_masks = mma7455_scan_masks;

	regmap_write(mma7455->regmap, MMA7455_REG_MCTL,
	MMA7455_MCTL_MODE_MEASURE);

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
	mma7455_trigger_handler, NULL);
	if (ret) {
	dev_err(dev, "unable to setup triggered buffer\n");
	return ret;
	}

	ret = iio_device_register(indio_dev);
	if (ret) {
	dev_err(dev, "unable to register device\n");
	iio_triggered_buffer_cleanup(indio_dev);
	return ret;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(mma7455_core_probe);

	int mma7455_core_remove(struct device *dev)
	{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct mma7455_data *mma7455 = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);

	regmap_write(mma7455->regmap, MMA7455_REG_MCTL,
	MMA7455_MCTL_MODE_STANDBY);

	return 0;
	}
	EXPORT_SYMBOL_GPL(mma7455_core_remove);

	MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
	MODULE_DESCRIPTION("Freescale MMA7455L core accelerometer driver");
	MODULE_LICENSE("GPL v2");