drivers/iio/pressure/ms5611_core.c - kernel/quantenna - Git at Google

 /*
  * MS5611 pressure and temperature sensor driver
  *
  * Copyright (c) Tomasz Duszynski <tduszyns@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.
  *
  * Data sheet:
  *  http://www.meas-spec.com/downloads/MS5611-01BA03.pdf
  *  http://www.meas-spec.com/downloads/MS5607-02BA03.pdf
  *
  */

 #include <linux/module.h>
 #include <linux/iio/iio.h>
 #include <linux/delay.h>
 #include <linux/regulator/consumer.h>

 #include <linux/iio/buffer.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/iio/trigger_consumer.h>
 #include "ms5611.h"

 static bool ms5611_prom_is_valid(u16 *prom, size_t len)
 {
 	int i, j;
 	uint16_t crc = 0, crc_orig = prom[7] & 0x000F;

 	prom[7] &= 0xFF00;

 	for (i = 0; i < len * 2; i++) {
 		if (i % 2 == 1)
 			crc ^= prom[i >> 1] & 0x00FF;
 		else
 			crc ^= prom[i >> 1] >> 8;

 		for (j = 0; j < 8; j++) {
 			if (crc & 0x8000)
 				crc = (crc << 1) ^ 0x3000;
 			else
 				crc <<= 1;
 		}
 	}

 	crc = (crc >> 12) & 0x000F;

 	return crc_orig != 0x0000 && crc == crc_orig;
 }

 static int ms5611_read_prom(struct iio_dev *indio_dev)
 {
 	int ret, i;
 	struct ms5611_state *st = iio_priv(indio_dev);

 	for (i = 0; i < MS5611_PROM_WORDS_NB; i++) {
 		ret = st->read_prom_word(&indio_dev->dev,
 					 i, &st->chip_info->prom[i]);
 		if (ret < 0) {
 			dev_err(&indio_dev->dev,
 				"failed to read prom at %d\n", i);
 			return ret;
 		}
 	}

 	if (!ms5611_prom_is_valid(st->chip_info->prom, MS5611_PROM_WORDS_NB)) {
 		dev_err(&indio_dev->dev, "PROM integrity check failed\n");
 		return -ENODEV;
 	}

 	return 0;
 }

 static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev,
 					 s32 *temp, s32 *pressure)
 {
 	int ret;
 	struct ms5611_state *st = iio_priv(indio_dev);

 	ret = st->read_adc_temp_and_pressure(&indio_dev->dev, temp, pressure);
 	if (ret < 0) {
 		dev_err(&indio_dev->dev,
 			"failed to read temperature and pressure\n");
 		return ret;
 	}

 	return st->chip_info->temp_and_pressure_compensate(st->chip_info,
 							   temp, pressure);
 }

 static int ms5611_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
 					       s32 *temp, s32 *pressure)
 {
 	s32 t = *temp, p = *pressure;
 	s64 off, sens, dt;

 	dt = t - (chip_info->prom[5] << 8);
 	off = ((s64)chip_info->prom[2] << 16) + ((chip_info->prom[4] * dt) >> 7);
 	sens = ((s64)chip_info->prom[1] << 15) + ((chip_info->prom[3] * dt) >> 8);

 	t = 2000 + ((chip_info->prom[6] * dt) >> 23);
 	if (t < 2000) {
 		s64 off2, sens2, t2;

 		t2 = (dt * dt) >> 31;
 		off2 = (5 * (t - 2000) * (t - 2000)) >> 1;
 		sens2 = off2 >> 1;

 		if (t < -1500) {
 			s64 tmp = (t + 1500) * (t + 1500);

 			off2 += 7 * tmp;
 			sens2 += (11 * tmp) >> 1;
 		}

 		t -= t2;
 		off -= off2;
 		sens -= sens2;
 	}

 	*temp = t;
 	*pressure = (((p * sens) >> 21) - off) >> 15;

 	return 0;
 }

 static int ms5607_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
 					       s32 *temp, s32 *pressure)
 {
 	s32 t = *temp, p = *pressure;
 	s64 off, sens, dt;

 	dt = t - (chip_info->prom[5] << 8);
 	off = ((s64)chip_info->prom[2] << 17) + ((chip_info->prom[4] * dt) >> 6);
 	sens = ((s64)chip_info->prom[1] << 16) + ((chip_info->prom[3] * dt) >> 7);

 	t = 2000 + ((chip_info->prom[6] * dt) >> 23);
 	if (t < 2000) {
 		s64 off2, sens2, t2, tmp;

 		t2 = (dt * dt) >> 31;
 		tmp = (t - 2000) * (t - 2000);
 		off2 = (61 * tmp) >> 4;
 		sens2 = tmp << 1;

 		if (t < -1500) {
 			tmp = (t + 1500) * (t + 1500);
 			off2 += 15 * tmp;
 			sens2 += 8 * tmp;
 		}

 		t -= t2;
 		off -= off2;
 		sens -= sens2;
 	}

 	*temp = t;
 	*pressure = (((p * sens) >> 21) - off) >> 15;

 	return 0;
 }

 static int ms5611_reset(struct iio_dev *indio_dev)
 {
 	int ret;
 	struct ms5611_state *st = iio_priv(indio_dev);

 	ret = st->reset(&indio_dev->dev);
 	if (ret < 0) {
 		dev_err(&indio_dev->dev, "failed to reset device\n");
 		return ret;
 	}

 	usleep_range(3000, 4000);

 	return 0;
 }

 static irqreturn_t ms5611_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct ms5611_state *st = iio_priv(indio_dev);
 	s32 buf[4]; /* s32 (pressure) + s32 (temp) + 2 * s32 (timestamp) */
 	int ret;

 	mutex_lock(&st->lock);
 	ret = ms5611_read_temp_and_pressure(indio_dev, &buf[1], &buf[0]);
 	mutex_unlock(&st->lock);
 	if (ret < 0)
 		goto err;

 	iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());

 err:
 	iio_trigger_notify_done(indio_dev->trig);

 	return IRQ_HANDLED;
 }

 static int ms5611_read_raw(struct iio_dev *indio_dev,
 			   struct iio_chan_spec const *chan,
 			   int *val, int *val2, long mask)
 {
 	int ret;
 	s32 temp, pressure;
 	struct ms5611_state *st = iio_priv(indio_dev);

 	switch (mask) {
 	case IIO_CHAN_INFO_PROCESSED:
 		mutex_lock(&st->lock);
 		ret = ms5611_read_temp_and_pressure(indio_dev,
 						    &temp, &pressure);
 		mutex_unlock(&st->lock);
 		if (ret < 0)
 			return ret;

 		switch (chan->type) {
 		case IIO_TEMP:
 			*val = temp * 10;
 			return IIO_VAL_INT;
 		case IIO_PRESSURE:
 			*val = pressure / 1000;
 			*val2 = (pressure % 1000) * 1000;
 			return IIO_VAL_INT_PLUS_MICRO;
 		default:
 			return -EINVAL;
 		}
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
 		case IIO_TEMP:
 			*val = 10;
 			return IIO_VAL_INT;
 		case IIO_PRESSURE:
 			*val = 0;
 			*val2 = 1000;
 			return IIO_VAL_INT_PLUS_MICRO;
 		default:
 			return -EINVAL;
 		}
 	}

 	return -EINVAL;
 }

 static const unsigned long ms5611_scan_masks[] = {0x3, 0};

 static struct ms5611_chip_info chip_info_tbl[] = {
 	[MS5611] = {
 		.temp_and_pressure_compensate = ms5611_temp_and_pressure_compensate,
 	},
 	[MS5607] = {
 		.temp_and_pressure_compensate = ms5607_temp_and_pressure_compensate,
 	}
 };

 static const struct iio_chan_spec ms5611_channels[] = {
 	{
 		.type = IIO_PRESSURE,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
 			BIT(IIO_CHAN_INFO_SCALE),
 		.scan_index = 0,
 		.scan_type = {
 			.sign = 's',
 			.realbits = 32,
 			.storagebits = 32,
 			.endianness = IIO_CPU,
 		},
 	},
 	{
 		.type = IIO_TEMP,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
 			BIT(IIO_CHAN_INFO_SCALE),
 		.scan_index = 1,
 		.scan_type = {
 			.sign = 's',
 			.realbits = 32,
 			.storagebits = 32,
 			.endianness = IIO_CPU,
 		},
 	},
 	IIO_CHAN_SOFT_TIMESTAMP(2),
 };

 static const struct iio_info ms5611_info = {
 	.read_raw = &ms5611_read_raw,
 	.driver_module = THIS_MODULE,
 };

 static int ms5611_init(struct iio_dev *indio_dev)
 {
 	int ret;
 	struct regulator *vdd = devm_regulator_get(indio_dev->dev.parent,
 	                                           "vdd");

 	/* Enable attached regulator if any. */
 	if (!IS_ERR(vdd)) {
 		ret = regulator_enable(vdd);
 		if (ret) {
 			dev_err(indio_dev->dev.parent,
 			        "failed to enable Vdd supply: %d\n", ret);
 			return ret;
 		}
 	}

 	ret = ms5611_reset(indio_dev);
 	if (ret < 0)
 		return ret;

 	return ms5611_read_prom(indio_dev);
 }

 int ms5611_probe(struct iio_dev *indio_dev, struct device *dev,
                  const char *name, int type)
 {
 	int ret;
 	struct ms5611_state *st = iio_priv(indio_dev);

 	mutex_init(&st->lock);
 	st->chip_info = &chip_info_tbl[type];
 	indio_dev->dev.parent = dev;
 	indio_dev->name = name;
 	indio_dev->info = &ms5611_info;
 	indio_dev->channels = ms5611_channels;
 	indio_dev->num_channels = ARRAY_SIZE(ms5611_channels);
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->available_scan_masks = ms5611_scan_masks;

 	ret = ms5611_init(indio_dev);
 	if (ret < 0)
 		return ret;

 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 					 ms5611_trigger_handler, NULL);
 	if (ret < 0) {
 		dev_err(dev, "iio triggered buffer setup failed\n");
 		return ret;
 	}

 	ret = iio_device_register(indio_dev);
 	if (ret < 0) {
 		dev_err(dev, "unable to register iio device\n");
 		goto err_buffer_cleanup;
 	}

 	return 0;

 err_buffer_cleanup:
 	iio_triggered_buffer_cleanup(indio_dev);

 	return ret;
 }
 EXPORT_SYMBOL(ms5611_probe);

 int ms5611_remove(struct iio_dev *indio_dev)
 {
 	iio_device_unregister(indio_dev);
 	iio_triggered_buffer_cleanup(indio_dev);

 	return 0;
 }
 EXPORT_SYMBOL(ms5611_remove);

 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
 MODULE_DESCRIPTION("MS5611 core driver");
 MODULE_LICENSE("GPL v2");
	/*
	* MS5611 pressure and temperature sensor driver
	*
	* Copyright (c) Tomasz Duszynski <tduszyns@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.
	*
	* Data sheet:
	* http://www.meas-spec.com/downloads/MS5611-01BA03.pdf
	* http://www.meas-spec.com/downloads/MS5607-02BA03.pdf
	*
	*/

	#include <linux/module.h>
	#include <linux/iio/iio.h>
	#include <linux/delay.h>
	#include <linux/regulator/consumer.h>

	#include <linux/iio/buffer.h>
	#include <linux/iio/triggered_buffer.h>
	#include <linux/iio/trigger_consumer.h>
	#include "ms5611.h"

	static bool ms5611_prom_is_valid(u16 *prom, size_t len)
	{
	int i, j;
	uint16_t crc = 0, crc_orig = prom[7] & 0x000F;

	prom[7] &= 0xFF00;

	for (i = 0; i < len * 2; i++) {
	if (i % 2 == 1)
	crc ^= prom[i >> 1] & 0x00FF;
	else
	crc ^= prom[i >> 1] >> 8;

	for (j = 0; j < 8; j++) {
	if (crc & 0x8000)
	crc = (crc << 1) ^ 0x3000;
	else
	crc <<= 1;
	}
	}

	crc = (crc >> 12) & 0x000F;

	return crc_orig != 0x0000 && crc == crc_orig;
	}

	static int ms5611_read_prom(struct iio_dev *indio_dev)
	{
	int ret, i;
	struct ms5611_state *st = iio_priv(indio_dev);

	for (i = 0; i < MS5611_PROM_WORDS_NB; i++) {
	ret = st->read_prom_word(&indio_dev->dev,
	i, &st->chip_info->prom[i]);
	if (ret < 0) {
	dev_err(&indio_dev->dev,
	"failed to read prom at %d\n", i);
	return ret;
	}
	}

	if (!ms5611_prom_is_valid(st->chip_info->prom, MS5611_PROM_WORDS_NB)) {
	dev_err(&indio_dev->dev, "PROM integrity check failed\n");
	return -ENODEV;
	}

	return 0;
	}

	static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev,
	s32 temp, s32 pressure)
	{
	int ret;
	struct ms5611_state *st = iio_priv(indio_dev);

	ret = st->read_adc_temp_and_pressure(&indio_dev->dev, temp, pressure);
	if (ret < 0) {
	dev_err(&indio_dev->dev,
	"failed to read temperature and pressure\n");
	return ret;
	}

	return st->chip_info->temp_and_pressure_compensate(st->chip_info,
	temp, pressure);
	}

	static int ms5611_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
	s32 temp, s32 pressure)
	{
	s32 t = temp, p = pressure;
	s64 off, sens, dt;

	dt = t - (chip_info->prom[5] << 8);
	off = ((s64)chip_info->prom[2] << 16) + ((chip_info->prom[4] * dt) >> 7);
	sens = ((s64)chip_info->prom[1] << 15) + ((chip_info->prom[3] * dt) >> 8);

	t = 2000 + ((chip_info->prom[6] * dt) >> 23);
	if (t < 2000) {
	s64 off2, sens2, t2;

	t2 = (dt * dt) >> 31;
	off2 = (5 * (t - 2000) * (t - 2000)) >> 1;
	sens2 = off2 >> 1;

	if (t < -1500) {
	s64 tmp = (t + 1500) * (t + 1500);

	off2 += 7 * tmp;
	sens2 += (11 * tmp) >> 1;
	}

	t -= t2;
	off -= off2;
	sens -= sens2;
	}

	*temp = t;
	pressure = (((p sens) >> 21) - off) >> 15;

	return 0;
	}

	static int ms5607_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
	s32 temp, s32 pressure)
	{
	s32 t = temp, p = pressure;
	s64 off, sens, dt;

	dt = t - (chip_info->prom[5] << 8);
	off = ((s64)chip_info->prom[2] << 17) + ((chip_info->prom[4] * dt) >> 6);
	sens = ((s64)chip_info->prom[1] << 16) + ((chip_info->prom[3] * dt) >> 7);

	t = 2000 + ((chip_info->prom[6] * dt) >> 23);
	if (t < 2000) {
	s64 off2, sens2, t2, tmp;

	t2 = (dt * dt) >> 31;
	tmp = (t - 2000) * (t - 2000);
	off2 = (61 * tmp) >> 4;
	sens2 = tmp << 1;

	if (t < -1500) {
	tmp = (t + 1500) * (t + 1500);
	off2 += 15 * tmp;
	sens2 += 8 * tmp;
	}

	t -= t2;
	off -= off2;
	sens -= sens2;
	}

	*temp = t;
	pressure = (((p sens) >> 21) - off) >> 15;

	return 0;
	}

	static int ms5611_reset(struct iio_dev *indio_dev)
	{
	int ret;
	struct ms5611_state *st = iio_priv(indio_dev);

	ret = st->reset(&indio_dev->dev);
	if (ret < 0) {
	dev_err(&indio_dev->dev, "failed to reset device\n");
	return ret;
	}

	usleep_range(3000, 4000);

	return 0;
	}

	static irqreturn_t ms5611_trigger_handler(int irq, void *p)
	{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct ms5611_state *st = iio_priv(indio_dev);
	s32 buf[4]; /* s32 (pressure) + s32 (temp) + 2 * s32 (timestamp) */
	int ret;

	mutex_lock(&st->lock);
	ret = ms5611_read_temp_and_pressure(indio_dev, &buf[1], &buf[0]);
	mutex_unlock(&st->lock);
	if (ret < 0)
	goto err;

	iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());

	err:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
	}

	static int ms5611_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	int ret;
	s32 temp, pressure;
	struct ms5611_state *st = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_PROCESSED:
	mutex_lock(&st->lock);
	ret = ms5611_read_temp_and_pressure(indio_dev,
	&temp, &pressure);
	mutex_unlock(&st->lock);
	if (ret < 0)
	return ret;

	switch (chan->type) {
	case IIO_TEMP:
	val = temp 10;
	return IIO_VAL_INT;
	case IIO_PRESSURE:
	*val = pressure / 1000;
	val2 = (pressure % 1000) 1000;
	return IIO_VAL_INT_PLUS_MICRO;
	default:
	return -EINVAL;
	}
	case IIO_CHAN_INFO_SCALE:
	switch (chan->type) {
	case IIO_TEMP:
	*val = 10;
	return IIO_VAL_INT;
	case IIO_PRESSURE:
	*val = 0;
	*val2 = 1000;
	return IIO_VAL_INT_PLUS_MICRO;
	default:
	return -EINVAL;
	}
	}

	return -EINVAL;
	}

	static const unsigned long ms5611_scan_masks[] = {0x3, 0};

	static struct ms5611_chip_info chip_info_tbl[] = {
	[MS5611] = {
	.temp_and_pressure_compensate = ms5611_temp_and_pressure_compensate,
	},
	[MS5607] = {
	.temp_and_pressure_compensate = ms5607_temp_and_pressure_compensate,
	}
	};

	static const struct iio_chan_spec ms5611_channels[] = {
	{
	.type = IIO_PRESSURE,
	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) \|
	BIT(IIO_CHAN_INFO_SCALE),
	.scan_index = 0,
	.scan_type = {
	.sign = 's',
	.realbits = 32,
	.storagebits = 32,
	.endianness = IIO_CPU,
	},
	},
	{
	.type = IIO_TEMP,
	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) \|
	BIT(IIO_CHAN_INFO_SCALE),
	.scan_index = 1,
	.scan_type = {
	.sign = 's',
	.realbits = 32,
	.storagebits = 32,
	.endianness = IIO_CPU,
	},
	},
	IIO_CHAN_SOFT_TIMESTAMP(2),
	};

	static const struct iio_info ms5611_info = {
	.read_raw = &ms5611_read_raw,
	.driver_module = THIS_MODULE,
	};

	static int ms5611_init(struct iio_dev *indio_dev)
	{
	int ret;
	struct regulator *vdd = devm_regulator_get(indio_dev->dev.parent,
	"vdd");

	/* Enable attached regulator if any. */
	if (!IS_ERR(vdd)) {
	ret = regulator_enable(vdd);
	if (ret) {
	dev_err(indio_dev->dev.parent,
	"failed to enable Vdd supply: %d\n", ret);
	return ret;
	}
	}

	ret = ms5611_reset(indio_dev);
	if (ret < 0)
	return ret;

	return ms5611_read_prom(indio_dev);
	}

	int ms5611_probe(struct iio_dev indio_dev, struct device dev,
	const char *name, int type)
	{
	int ret;
	struct ms5611_state *st = iio_priv(indio_dev);

	mutex_init(&st->lock);
	st->chip_info = &chip_info_tbl[type];
	indio_dev->dev.parent = dev;
	indio_dev->name = name;
	indio_dev->info = &ms5611_info;
	indio_dev->channels = ms5611_channels;
	indio_dev->num_channels = ARRAY_SIZE(ms5611_channels);
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->available_scan_masks = ms5611_scan_masks;

	ret = ms5611_init(indio_dev);
	if (ret < 0)
	return ret;

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
	ms5611_trigger_handler, NULL);
	if (ret < 0) {
	dev_err(dev, "iio triggered buffer setup failed\n");
	return ret;
	}

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
	dev_err(dev, "unable to register iio device\n");
	goto err_buffer_cleanup;
	}

	return 0;

	err_buffer_cleanup:
	iio_triggered_buffer_cleanup(indio_dev);

	return ret;
	}
	EXPORT_SYMBOL(ms5611_probe);

	int ms5611_remove(struct iio_dev *indio_dev)
	{
	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);

	return 0;
	}
	EXPORT_SYMBOL(ms5611_remove);

	MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
	MODULE_DESCRIPTION("MS5611 core driver");
	MODULE_LICENSE("GPL v2");