[PATCH] iio: pressure: add support for MS5611 pressure and temperature sensor

[PATCH] iio: pressure: add support for MS5611 pressure and temperature sensor

[Tomasz Duszynski]

Add support for Measurement Specialities MS5611 pressure
and temperature sensor.

Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
---
 drivers/iio/pressure/Kconfig       |  27 +++++
 drivers/iio/pressure/Makefile      |   4 +
 drivers/iio/pressure/ms5611.h      |  44 +++++++
 drivers/iio/pressure/ms5611_core.c | 239 +++++++++++++++++++++++++++++++++++++
 drivers/iio/pressure/ms5611_i2c.c  | 131 ++++++++++++++++++++
 drivers/iio/pressure/ms5611_spi.c  | 137 +++++++++++++++++++++
 6 files changed, 582 insertions(+)
 create mode 100644 drivers/iio/pressure/ms5611.h
 create mode 100644 drivers/iio/pressure/ms5611_core.c
 create mode 100644 drivers/iio/pressure/ms5611_i2c.c
 create mode 100644 drivers/iio/pressure/ms5611_spi.c

diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
index a3be537..fa62950 100644
--- a/drivers/iio/pressure/Kconfig
+++ b/drivers/iio/pressure/Kconfig
@@ -52,6 +52,33 @@ config MPL3115
           To compile this driver as a module, choose M here: the module
           will be called mpl3115.
 
+config MS5611
+	tristate "Measurement Specialities MS5611 pressure sensor driver"
+	help
+	  Say Y here to build support for the Measurement Specialities
+	  MS5611 pressure and temperature sensor.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called ms5611_core.
+
+config MS5611_I2C
+	tristate "support I2C bus connection"
+	depends on I2C && MS5611
+	help
+	  Say Y here to build I2C bus support for MS5611.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called ms5611_i2c.
+
+config MS5611_SPI
+	tristate "support SPI bus connection"
+	depends on SPI_MASTER && MS5611
+	help
+	  Say Y here to build SPI bus support for MS5611.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called ms5611_spi.
+
 config IIO_ST_PRESS
 	tristate "STMicroelectronics pressure sensor Driver"
 	depends on (I2C || SPI_MASTER) && SYSFS
diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile
index 88011f2..82f34f6 100644
--- a/drivers/iio/pressure/Makefile
+++ b/drivers/iio/pressure/Makefile
@@ -14,3 +14,7 @@ obj-$(CONFIG_T5403) += t5403.o
 
 obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o
 obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o
+
+obj-$(CONFIG_MS5611) += ms5611_core.o
+obj-$(CONFIG_MS5611_I2C) += ms5611_i2c.o
+obj-$(CONFIG_MS5611_SPI) += ms5611_spi.o
diff --git a/drivers/iio/pressure/ms5611.h b/drivers/iio/pressure/ms5611.h
new file mode 100644
index 0000000..f4d44a5
--- /dev/null
+++ b/drivers/iio/pressure/ms5611.h
@@ -0,0 +1,44 @@
+/*
+ * 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.
+ *
+ */
+#ifndef _MS5611_H
+#define _MS5611_H
+
+#include <linux/device.h>
+#include <linux/iio/iio.h>
+#include <linux/mutex.h>
+
+#define MS5611_RESET			0x1e
+#define MS5611_READ_ADC			0x00
+#define MS5611_READ_PROM_WORD		0xA0
+#define MS5611_START_TEMP_CONV		0x58
+#define MS5611_START_PRESSURE_CONV	0x48
+
+#define MS5611_CONV_TIME_MIN		9040
+#define MS5611_CONV_TIME_MAX		10000
+
+#define MS5611_PROM_WORDS_NB		8
+
+struct ms5611_state {
+	void *client;
+	struct mutex lock;
+
+	int (*reset)(struct device *dev);
+	int (*read_prom_word)(struct device *dev, int index, u16 *word);
+	int (*read_adc_temp_and_pressure)(struct device *dev,
+					  s32 *temp, s32 *pressure);
+
+	u16 prom[MS5611_PROM_WORDS_NB];
+};
+
+int ms5611_probe(struct iio_dev *indio_dev, struct device *dev);
+int ms5611_remove(struct iio_dev *indio_dev);
+
+#endif /* _MS5611_H */
diff --git a/drivers/iio/pressure/ms5611_core.c b/drivers/iio/pressure/ms5611_core.c
new file mode 100644
index 0000000..e4deda7
--- /dev/null
+++ b/drivers/iio/pressure/ms5611_core.c
@@ -0,0 +1,239 @@
+/*
+ * 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
+ *
+ */
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/delay.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->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->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;
+	s32 t, p;
+	s64 off, off2, sens, sens2, dt, t2 = 0;
+	struct ms5611_state *st = iio_priv(indio_dev);
+
+	ret = st->read_adc_temp_and_pressure(&indio_dev->dev, &t, &p);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev,
+			"failed to read temperature and pressure\n");
+		return ret;
+	}
+
+	dt = t - (st->prom[5] << 8);
+	off = ((s64)st->prom[2] << 16) + ((st->prom[4] * dt) >> 7);
+	sens = ((s64)st->prom[1] << 15) + ((st->prom[3] * dt) >> 8);
+
+	t = 2000 + ((st->prom[6] * dt) >> 23);
+	if (t < 2000) {
+		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;
+		}
+
+		off -= off2;
+		sens -= sens2;
+	}
+
+	*temp = t - t2;
+	*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 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)
+			break;
+
+		switch (chan->type) {
+		case IIO_TEMP:
+			*val = temp;
+			ret = IIO_VAL_INT;
+			break;
+		case IIO_PRESSURE:
+			*val = pressure;
+			ret = IIO_VAL_INT;
+			break;
+		default:
+			ret = -EINVAL;
+		}
+		break;
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_TEMP:
+			*val = 0;
+			*val2 = 10000;
+			ret = IIO_VAL_INT_PLUS_MICRO;
+			break;
+		case IIO_PRESSURE:
+			*val = 0;
+			*val2 = 1000;
+			ret = IIO_VAL_INT_PLUS_MICRO;
+			break;
+		default:
+			ret = -EINVAL;
+		}
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static const struct iio_chan_spec ms5611_channels[] = {
+	{
+		.type = IIO_PRESSURE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+			BIT(IIO_CHAN_INFO_SCALE)
+	},
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+			BIT(IIO_CHAN_INFO_SCALE)
+	}
+};
+
+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;
+
+	ret = ms5611_reset(indio_dev);
+	if (ret < 0)
+		return ret;
+
+	ret = ms5611_read_prom(indio_dev);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+int ms5611_probe(struct iio_dev *indio_dev, struct device *dev)
+{
+	int ret;
+	struct ms5611_state *st = iio_priv(indio_dev);
+
+	mutex_init(&st->lock);
+	indio_dev->dev.parent = dev;
+	indio_dev->name = dev->driver->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;
+
+	ret = ms5611_init(indio_dev);
+	if (ret < 0)
+		return ret;
+
+	return iio_device_register(indio_dev);
+}
+EXPORT_SYMBOL(ms5611_probe);
+
+int ms5611_remove(struct iio_dev *indio_dev)
+{
+	iio_device_unregister(indio_dev);
+	return 0;
+}
+EXPORT_SYMBOL(ms5611_remove);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("MS5611 core driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/pressure/ms5611_i2c.c b/drivers/iio/pressure/ms5611_i2c.c
new file mode 100644
index 0000000..920fa78
--- /dev/null
+++ b/drivers/iio/pressure/ms5611_i2c.c
@@ -0,0 +1,131 @@
+/*
+ * MS5611 pressure and temperature sensor driver (I2C bus)
+ *
+ * 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.
+ *
+ */
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+#include "ms5611.h"
+
+static int ms5611_reset(struct device *dev)
+{
+	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
+
+	return i2c_smbus_write_byte(st->client, MS5611_RESET);
+}
+
+static int ms5611_read_prom_word(struct device *dev, int index, u16 *word)
+{
+	int ret;
+	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
+
+	ret = i2c_smbus_read_word_swapped(st->client,
+			MS5611_READ_PROM_WORD + (index << 1));
+	if (ret < 0)
+		return ret;
+
+	*word = ret;
+	return 0;
+}
+
+static int ms5611_read_adc(struct ms5611_state *st, s32 *val)
+{
+	int ret;
+	u8 buf[3];
+
+	ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
+					    3, buf);
+	if (ret < 0)
+		return ret;
+
+	*val = (buf[0] << 16) | (buf[1] << 8) | buf[0];
+	return 0;
+}
+
+static int ms5611_read_adc_temp_and_pressure(struct device *dev,
+					     s32 *temp, s32 *pressure)
+{
+	int ret;
+	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
+
+	ret = i2c_smbus_write_byte(st->client, MS5611_START_TEMP_CONV);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
+
+	ret = ms5611_read_adc(st, temp);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte(st->client, MS5611_START_PRESSURE_CONV);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
+
+	ret = ms5611_read_adc(st, pressure);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int ms5611_i2c_probe(struct i2c_client *client,
+			    const struct i2c_device_id *id)
+{
+	struct ms5611_state *st;
+	struct iio_dev *indio_dev;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_WRITE_BYTE |
+				     I2C_FUNC_SMBUS_READ_WORD_DATA |
+				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+		return -ENODEV;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, indio_dev);
+	st = iio_priv(indio_dev);
+	st->reset = ms5611_reset;
+	st->read_prom_word = ms5611_read_prom_word;
+	st->read_adc_temp_and_pressure = ms5611_read_adc_temp_and_pressure;
+	st->client = client;
+
+	return ms5611_probe(indio_dev, &client->dev);
+}
+
+static int ms5611_i2c_remove(struct i2c_client *client)
+{
+	return ms5611_remove(i2c_get_clientdata(client));
+}
+
+static const struct i2c_device_id ms5611_id[] = {
+	{ "ms5611", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ms5611_id);
+
+static struct i2c_driver ms5611_driver = {
+	.driver = {
+		.name = "ms5611",
+		.owner = THIS_MODULE,
+	},
+	.id_table = ms5611_id,
+	.probe = ms5611_i2c_probe,
+	.remove = ms5611_i2c_remove,
+};
+module_i2c_driver(ms5611_driver);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("MS5611 i2c driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/pressure/ms5611_spi.c b/drivers/iio/pressure/ms5611_spi.c
new file mode 100644
index 0000000..eb3fee5
--- /dev/null
+++ b/drivers/iio/pressure/ms5611_spi.c
@@ -0,0 +1,137 @@
+/*
+ * MS5611 pressure and temperature sensor driver (SPI bus)
+ *
+ * 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.
+ *
+ */
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+
+#include "ms5611.h"
+
+static int ms5611_reset(struct device *dev)
+{
+	u8 cmd = MS5611_RESET;
+	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
+
+	return spi_write(st->client, &cmd, 1);
+}
+
+static int ms5611_read_prom_word(struct device *dev, int index, u16 *word)
+{
+	int ret;
+	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
+
+	ret = spi_w8r16be(st->client, MS5611_READ_PROM_WORD + (index << 1));
+	if (ret < 0)
+		return ret;
+
+	*word = ret;
+	return 0;
+}
+
+static int ms5611_read_adc(struct device *dev, s32 *val)
+{
+	int ret;
+	u8 buf[3];
+	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
+
+	buf[0] = MS5611_READ_ADC;
+
+	ret = spi_write_then_read(st->client, buf, 1, buf, 3);
+	if (ret < 0)
+		return ret;
+
+	*val = (buf[0] << 16) | (buf[1] << 8) | buf[0];
+	return 0;
+}
+
+static int ms5611_read_adc_temp_and_pressure(struct device *dev,
+					     s32 *temp, s32 *pressure)
+{
+	u8 cmd;
+	int ret;
+	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
+
+	cmd = MS5611_START_TEMP_CONV;
+	ret = spi_write(st->client, &cmd, 1);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
+
+	ret = ms5611_read_adc(dev, temp);
+	if (ret < 0)
+		return ret;
+
+	cmd = MS5611_START_PRESSURE_CONV;
+	ret = spi_write(st->client, &cmd, 1);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
+
+	ret = ms5611_read_adc(dev, pressure);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int ms5611_spi_probe(struct spi_device *spi)
+{
+	int ret;
+	struct ms5611_state *st;
+	struct iio_dev *indio_dev;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	spi->mode = SPI_MODE_0;
+	spi->max_speed_hz = 20000000;
+	spi->bits_per_word = 8;
+	ret = spi_setup(spi);
+	if (ret < 0)
+		return ret;
+
+	spi_set_drvdata(spi, indio_dev);
+	st = iio_priv(indio_dev);
+	st->reset = ms5611_reset;
+	st->read_prom_word = ms5611_read_prom_word;
+	st->read_adc_temp_and_pressure = ms5611_read_adc_temp_and_pressure;
+	st->client = spi;
+
+	return ms5611_probe(indio_dev, &spi->dev);
+}
+
+static int ms5611_spi_remove(struct spi_device *spi)
+{
+	return ms5611_remove(spi_get_drvdata(spi));
+}
+
+static const struct spi_device_id ms5611_id[] = {
+	{ "ms5611", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, ms5611_id);
+
+static struct spi_driver ms5611_driver = {
+	.driver = {
+		.name = "ms5611",
+		.owner = THIS_MODULE,
+	},
+	.id_table = ms5611_id,
+	.probe = ms5611_spi_probe,
+	.remove = ms5611_spi_remove,
+};
+module_spi_driver(ms5611_driver);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("MS5611 spi driver");
+MODULE_LICENSE("GPL v2");
-- 
2.3.1

Re: [PATCH] iio: pressure: add support for MS5611 pressure and temperature sensor

[Peter Meerwald]

> Add support for Measurement Specialities MS5611 pressure
> and temperature sensor.

comments inline below
 
> Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
> ---
>  drivers/iio/pressure/Kconfig       |  27 +++++
>  drivers/iio/pressure/Makefile      |   4 +
>  drivers/iio/pressure/ms5611.h      |  44 +++++++
>  drivers/iio/pressure/ms5611_core.c | 239 +++++++++++++++++++++++++++++++++++++
>  drivers/iio/pressure/ms5611_i2c.c  | 131 ++++++++++++++++++++
>  drivers/iio/pressure/ms5611_spi.c  | 137 +++++++++++++++++++++
>  6 files changed, 582 insertions(+)
>  create mode 100644 drivers/iio/pressure/ms5611.h
>  create mode 100644 drivers/iio/pressure/ms5611_core.c
>  create mode 100644 drivers/iio/pressure/ms5611_i2c.c
>  create mode 100644 drivers/iio/pressure/ms5611_spi.c
> 
> diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
> index a3be537..fa62950 100644
> --- a/drivers/iio/pressure/Kconfig
> +++ b/drivers/iio/pressure/Kconfig
> @@ -52,6 +52,33 @@ config MPL3115
>            To compile this driver as a module, choose M here: the module
>            will be called mpl3115.
>  
> +config MS5611
> +	tristate "Measurement Specialities MS5611 pressure sensor driver"
> +	help
> +	  Say Y here to build support for the Measurement Specialities
> +	  MS5611 pressure and temperature sensor.
> +
> +	  To compile this driver as a module, choose M here: the module will
> +	  be called ms5611_core.
> +
> +config MS5611_I2C
> +	tristate "support I2C bus connection"
> +	depends on I2C && MS5611
> +	help
> +	  Say Y here to build I2C bus support for MS5611.
> +
> +	  To compile this driver as a module, choose M here: the module will
> +	  be called ms5611_i2c.
> +
> +config MS5611_SPI
> +	tristate "support SPI bus connection"
> +	depends on SPI_MASTER && MS5611
> +	help
> +	  Say Y here to build SPI bus support for MS5611.
> +
> +	  To compile this driver as a module, choose M here: the module will
> +	  be called ms5611_spi.
> +
>  config IIO_ST_PRESS
>  	tristate "STMicroelectronics pressure sensor Driver"
>  	depends on (I2C || SPI_MASTER) && SYSFS
> diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile
> index 88011f2..82f34f6 100644
> --- a/drivers/iio/pressure/Makefile
> +++ b/drivers/iio/pressure/Makefile
> @@ -14,3 +14,7 @@ obj-$(CONFIG_T5403) += t5403.o
>  
>  obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o
>  obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o
> +

alphebetic order?

> +obj-$(CONFIG_MS5611) += ms5611_core.o
> +obj-$(CONFIG_MS5611_I2C) += ms5611_i2c.o
> +obj-$(CONFIG_MS5611_SPI) += ms5611_spi.o
> diff --git a/drivers/iio/pressure/ms5611.h b/drivers/iio/pressure/ms5611.h
> new file mode 100644
> index 0000000..f4d44a5
> --- /dev/null
> +++ b/drivers/iio/pressure/ms5611.h
> @@ -0,0 +1,44 @@
> +/*
> + * 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.
> + *
> + */
> +#ifndef _MS5611_H
> +#define _MS5611_H
> +
> +#include <linux/device.h>
> +#include <linux/iio/iio.h>
> +#include <linux/mutex.h>
> +
> +#define MS5611_RESET			0x1e
> +#define MS5611_READ_ADC			0x00
> +#define MS5611_READ_PROM_WORD		0xA0
> +#define MS5611_START_TEMP_CONV		0x58
> +#define MS5611_START_PRESSURE_CONV	0x48
> +
> +#define MS5611_CONV_TIME_MIN		9040
> +#define MS5611_CONV_TIME_MAX		10000
> +
> +#define MS5611_PROM_WORDS_NB		8
> +
> +struct ms5611_state {
> +	void *client;
> +	struct mutex lock;
> +
> +	int (*reset)(struct device *dev);
> +	int (*read_prom_word)(struct device *dev, int index, u16 *word);
> +	int (*read_adc_temp_and_pressure)(struct device *dev,
> +					  s32 *temp, s32 *pressure);
> +

probably regmap could be used to avoid duplicate code?

> +	u16 prom[MS5611_PROM_WORDS_NB];
> +};
> +
> +int ms5611_probe(struct iio_dev *indio_dev, struct device *dev);
> +int ms5611_remove(struct iio_dev *indio_dev);
> +
> +#endif /* _MS5611_H */
> diff --git a/drivers/iio/pressure/ms5611_core.c b/drivers/iio/pressure/ms5611_core.c
> new file mode 100644
> index 0000000..e4deda7
> --- /dev/null
> +++ b/drivers/iio/pressure/ms5611_core.c
> @@ -0,0 +1,239 @@
> +/*
> + * 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
> + *
> + */
> +#include <linux/module.h>
> +#include <linux/iio/iio.h>
> +#include <linux/delay.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->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->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;
> +	s32 t, p;
> +	s64 off, off2, sens, sens2, dt, t2 = 0;

some of the variables could be declared with a more local scope, such as 
tmp below (e.g. sens2)

> +	struct ms5611_state *st = iio_priv(indio_dev);
> +
> +	ret = st->read_adc_temp_and_pressure(&indio_dev->dev, &t, &p);
> +	if (ret < 0) {
> +		dev_err(&indio_dev->dev,
> +			"failed to read temperature and pressure\n");
> +		return ret;
> +	}
> +
> +	dt = t - (st->prom[5] << 8);
> +	off = ((s64)st->prom[2] << 16) + ((st->prom[4] * dt) >> 7);
> +	sens = ((s64)st->prom[1] << 15) + ((st->prom[3] * dt) >> 8);
> +
> +	t = 2000 + ((st->prom[6] * dt) >> 23);
> +	if (t < 2000) {
> +		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;
> +		}
> +
> +		off -= off2;
> +		sens -= sens2;
> +	}
> +
> +	*temp = t - t2;
> +	*pressure = (((p * sens) >> 21) - off) >> 15;

probably newline here makes it look nicer

> +	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 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)
> +			break;
> +
> +		switch (chan->type) {
> +		case IIO_TEMP:
> +			*val = temp;
> +			ret = IIO_VAL_INT;
> +			break;
> +		case IIO_PRESSURE:
> +			*val = pressure;
> +			ret = IIO_VAL_INT;
> +			break;
> +		default:
> +			ret = -EINVAL;

probably return -EINVAL directly

> +		}

probably return IIO_VAL_INT here

> +		break;
> +	case IIO_CHAN_INFO_SCALE:

SCALE is not necessary when _PROCESSED is already doing all the scaling 
such that the output is in milli-Celsius and kilo-Pascal

> +		switch (chan->type) {
> +		case IIO_TEMP:
> +			*val = 0;
> +			*val2 = 10000;
> +			ret = IIO_VAL_INT_PLUS_MICRO;
> +			break;
> +		case IIO_PRESSURE:
> +			*val = 0;
> +			*val2 = 1000;
> +			ret = IIO_VAL_INT_PLUS_MICRO;
> +			break;
> +		default:
> +			ret = -EINVAL;
> +		}
> +		break;
> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +	return ret;
> +}
> +
> +static const struct iio_chan_spec ms5611_channels[] = {
> +	{
> +		.type = IIO_PRESSURE,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +			BIT(IIO_CHAN_INFO_SCALE)
> +	},
> +	{
> +		.type = IIO_TEMP,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +			BIT(IIO_CHAN_INFO_SCALE)
> +	}
> +};
> +
> +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;
> +
> +	ret = ms5611_reset(indio_dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = ms5611_read_prom(indio_dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +int ms5611_probe(struct iio_dev *indio_dev, struct device *dev)
> +{
> +	int ret;
> +	struct ms5611_state *st = iio_priv(indio_dev);
> +
> +	mutex_init(&st->lock);
> +	indio_dev->dev.parent = dev;
> +	indio_dev->name = dev->driver->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;
> +
> +	ret = ms5611_init(indio_dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	return iio_device_register(indio_dev);

use devm_iio_device_register() and save _remove()

> +}
> +EXPORT_SYMBOL(ms5611_probe);
> +
> +int ms5611_remove(struct iio_dev *indio_dev)
> +{
> +	iio_device_unregister(indio_dev);
> +	return 0;
> +}
> +EXPORT_SYMBOL(ms5611_remove);
> +
> +MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
> +MODULE_DESCRIPTION("MS5611 core driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/iio/pressure/ms5611_i2c.c b/drivers/iio/pressure/ms5611_i2c.c
> new file mode 100644
> index 0000000..920fa78
> --- /dev/null
> +++ b/drivers/iio/pressure/ms5611_i2c.c
> @@ -0,0 +1,131 @@
> +/*
> + * MS5611 pressure and temperature sensor driver (I2C bus)
> + *
> + * 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.
> + *
> + */
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +
> +#include "ms5611.h"
> +
> +static int ms5611_reset(struct device *dev)
> +{
> +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> +
> +	return i2c_smbus_write_byte(st->client, MS5611_RESET);
> +}
> +
> +static int ms5611_read_prom_word(struct device *dev, int index, u16 *word)
> +{
> +	int ret;
> +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> +
> +	ret = i2c_smbus_read_word_swapped(st->client,
> +			MS5611_READ_PROM_WORD + (index << 1));
> +	if (ret < 0)
> +		return ret;
> +
> +	*word = ret;
> +	return 0;
> +}
> +
> +static int ms5611_read_adc(struct ms5611_state *st, s32 *val)
> +{
> +	int ret;
> +	u8 buf[3];
> +
> +	ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
> +					    3, buf);
> +	if (ret < 0)
> +		return ret;
> +
> +	*val = (buf[0] << 16) | (buf[1] << 8) | buf[0];

should be buf[2] at the end

> +	return 0;
> +}
> +
> +static int ms5611_read_adc_temp_and_pressure(struct device *dev,
> +					     s32 *temp, s32 *pressure)
> +{
> +	int ret;
> +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> +
> +	ret = i2c_smbus_write_byte(st->client, MS5611_START_TEMP_CONV);
> +	if (ret < 0)
> +		return ret;
> +
> +	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
> +
> +	ret = ms5611_read_adc(st, temp);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = i2c_smbus_write_byte(st->client, MS5611_START_PRESSURE_CONV);
> +	if (ret < 0)
> +		return ret;
> +
> +	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
> +
> +	ret = ms5611_read_adc(st, pressure);
> +	if (ret < 0)
> +		return ret;

just return ret?

> +
> +	return 0;
> +}
> +
> +static int ms5611_i2c_probe(struct i2c_client *client,
> +			    const struct i2c_device_id *id)
> +{
> +	struct ms5611_state *st;
> +	struct iio_dev *indio_dev;
> +
> +	if (!i2c_check_functionality(client->adapter,
> +				     I2C_FUNC_SMBUS_WRITE_BYTE |
> +				     I2C_FUNC_SMBUS_READ_WORD_DATA |
> +				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
> +		return -ENODEV;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	i2c_set_clientdata(client, indio_dev);
> +	st = iio_priv(indio_dev);
> +	st->reset = ms5611_reset;
> +	st->read_prom_word = ms5611_read_prom_word;
> +	st->read_adc_temp_and_pressure = ms5611_read_adc_temp_and_pressure;
> +	st->client = client;
> +
> +	return ms5611_probe(indio_dev, &client->dev);
> +}
> +
> +static int ms5611_i2c_remove(struct i2c_client *client)
> +{
> +	return ms5611_remove(i2c_get_clientdata(client));
> +}
> +
> +static const struct i2c_device_id ms5611_id[] = {
> +	{ "ms5611", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, ms5611_id);
> +
> +static struct i2c_driver ms5611_driver = {
> +	.driver = {
> +		.name = "ms5611",
> +		.owner = THIS_MODULE,
> +	},
> +	.id_table = ms5611_id,
> +	.probe = ms5611_i2c_probe,
> +	.remove = ms5611_i2c_remove,
> +};
> +module_i2c_driver(ms5611_driver);
> +
> +MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
> +MODULE_DESCRIPTION("MS5611 i2c driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/iio/pressure/ms5611_spi.c b/drivers/iio/pressure/ms5611_spi.c
> new file mode 100644
> index 0000000..eb3fee5
> --- /dev/null
> +++ b/drivers/iio/pressure/ms5611_spi.c
> @@ -0,0 +1,137 @@
> +/*
> + * MS5611 pressure and temperature sensor driver (SPI bus)
> + *
> + * 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.
> + *
> + */
> +#include <linux/delay.h>
> +#include <linux/module.h>
> +#include <linux/spi/spi.h>
> +
> +#include "ms5611.h"
> +
> +static int ms5611_reset(struct device *dev)
> +{
> +	u8 cmd = MS5611_RESET;
> +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> +
> +	return spi_write(st->client, &cmd, 1);
> +}
> +
> +static int ms5611_read_prom_word(struct device *dev, int index, u16 *word)
> +{
> +	int ret;
> +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> +
> +	ret = spi_w8r16be(st->client, MS5611_READ_PROM_WORD + (index << 1));
> +	if (ret < 0)
> +		return ret;
> +
> +	*word = ret;
> +	return 0;
> +}
> +
> +static int ms5611_read_adc(struct device *dev, s32 *val)
> +{
> +	int ret;
> +	u8 buf[3];
> +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> +
> +	buf[0] = MS5611_READ_ADC;
> +
> +	ret = spi_write_then_read(st->client, buf, 1, buf, 3);
> +	if (ret < 0)
> +		return ret;
> +
> +	*val = (buf[0] << 16) | (buf[1] << 8) | buf[0];

buf[2]?

> +	return 0;
> +}
> +
> +static int ms5611_read_adc_temp_and_pressure(struct device *dev,
> +					     s32 *temp, s32 *pressure)
> +{
> +	u8 cmd;
> +	int ret;
> +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> +
> +	cmd = MS5611_START_TEMP_CONV;
> +	ret = spi_write(st->client, &cmd, 1);
> +	if (ret < 0)
> +		return ret;
> +
> +	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
> +
> +	ret = ms5611_read_adc(dev, temp);
> +	if (ret < 0)
> +		return ret;
> +
> +	cmd = MS5611_START_PRESSURE_CONV;
> +	ret = spi_write(st->client, &cmd, 1);
> +	if (ret < 0)
> +		return ret;
> +
> +	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
> +
> +	ret = ms5611_read_adc(dev, pressure);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ms5611_spi_probe(struct spi_device *spi)
> +{
> +	int ret;
> +	struct ms5611_state *st;
> +	struct iio_dev *indio_dev;
> +
> +	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	spi->mode = SPI_MODE_0;
> +	spi->max_speed_hz = 20000000;
> +	spi->bits_per_word = 8;
> +	ret = spi_setup(spi);
> +	if (ret < 0)
> +		return ret;
> +
> +	spi_set_drvdata(spi, indio_dev);
> +	st = iio_priv(indio_dev);
> +	st->reset = ms5611_reset;
> +	st->read_prom_word = ms5611_read_prom_word;
> +	st->read_adc_temp_and_pressure = ms5611_read_adc_temp_and_pressure;
> +	st->client = spi;
> +
> +	return ms5611_probe(indio_dev, &spi->dev);
> +}
> +
> +static int ms5611_spi_remove(struct spi_device *spi)
> +{
> +	return ms5611_remove(spi_get_drvdata(spi));
> +}
> +
> +static const struct spi_device_id ms5611_id[] = {
> +	{ "ms5611", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(spi, ms5611_id);
> +
> +static struct spi_driver ms5611_driver = {
> +	.driver = {
> +		.name = "ms5611",
> +		.owner = THIS_MODULE,
> +	},
> +	.id_table = ms5611_id,
> +	.probe = ms5611_spi_probe,
> +	.remove = ms5611_spi_remove,
> +};
> +module_spi_driver(ms5611_driver);
> +
> +MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
> +MODULE_DESCRIPTION("MS5611 spi driver");
> +MODULE_LICENSE("GPL v2");
> 

-- 

Peter Meerwald
+43-664-2444418 (mobile)

Re: [PATCH] iio: pressure: add support for MS5611 pressure and temperature sensor

[Daniel Baluta]

Hi Tomasz,

On Sun, Mar 8, 2015 at 7:29 PM, Tomasz Duszynski <tduszyns@gmail.com> wrote:
> Add support for Measurement Specialities MS5611 pressure
> and temperature sensor.
>
> Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>

<snip>

> +++ b/drivers/iio/pressure/ms5611_i2c.c
> @@ -0,0 +1,131 @@
> +/*
> + * MS5611 pressure and temperature sensor driver (I2C bus)
> + *
> + * 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.
> + *

If fixed, please specify here the I2C slave address.

> + */
> +#include <linux/delay.h>

<snip>

> +static int ms5611_read_adc(struct ms5611_state *st, s32 *val)
> +{
> +       int ret;
> +       u8 buf[3];
> +
> +       ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
> +                                           3, buf);
> +       if (ret < 0)
> +               return ret;
> +
> +       *val = (buf[0] << 16) | (buf[1] << 8) | buf[0];

Hmm, buf[2] is not used. Is this intended or the formula
has buf[2] as the last OR factor?

thanks,
Daniel.

Re: [PATCH] iio: pressure: add support for MS5611 pressure and temperature sensor

[tduszyns]

Hi Peter,

On Sun, Mar 08, 2015 at 07:16:00PM +0100, Peter Meerwald wrote:
> > Add support for Measurement Specialities MS5611 pressure
> > and temperature sensor.
>
> comments inline below
>
> > Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
> > ---
> >  drivers/iio/pressure/Kconfig       |  27 +++++
> >  drivers/iio/pressure/Makefile      |   4 +
> >  drivers/iio/pressure/ms5611.h      |  44 +++++++
> >  drivers/iio/pressure/ms5611_core.c | 239 +++++++++++++++++++++++++++++++++++++
> >  drivers/iio/pressure/ms5611_i2c.c  | 131 ++++++++++++++++++++
> >  drivers/iio/pressure/ms5611_spi.c  | 137 +++++++++++++++++++++
> >  6 files changed, 582 insertions(+)
> >  create mode 100644 drivers/iio/pressure/ms5611.h
> >  create mode 100644 drivers/iio/pressure/ms5611_core.c
> >  create mode 100644 drivers/iio/pressure/ms5611_i2c.c
> >  create mode 100644 drivers/iio/pressure/ms5611_spi.c
> >
> > diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
> > index a3be537..fa62950 100644
> > --- a/drivers/iio/pressure/Kconfig
> > +++ b/drivers/iio/pressure/Kconfig
> > @@ -52,6 +52,33 @@ config MPL3115
> >            To compile this driver as a module, choose M here: the module
> >            will be called mpl3115.
> >
> > +config MS5611
> > +	tristate "Measurement Specialities MS5611 pressure sensor driver"
> > +	help
> > +	  Say Y here to build support for the Measurement Specialities
> > +	  MS5611 pressure and temperature sensor.
> > +
> > +	  To compile this driver as a module, choose M here: the module will
> > +	  be called ms5611_core.
> > +
> > +config MS5611_I2C
> > +	tristate "support I2C bus connection"
> > +	depends on I2C && MS5611
> > +	help
> > +	  Say Y here to build I2C bus support for MS5611.
> > +
> > +	  To compile this driver as a module, choose M here: the module will
> > +	  be called ms5611_i2c.
> > +
> > +config MS5611_SPI
> > +	tristate "support SPI bus connection"
> > +	depends on SPI_MASTER && MS5611
> > +	help
> > +	  Say Y here to build SPI bus support for MS5611.
> > +
> > +	  To compile this driver as a module, choose M here: the module will
> > +	  be called ms5611_spi.
> > +
> >  config IIO_ST_PRESS
> >  	tristate "STMicroelectronics pressure sensor Driver"
> >  	depends on (I2C || SPI_MASTER) && SYSFS
> > diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile
> > index 88011f2..82f34f6 100644
> > --- a/drivers/iio/pressure/Makefile
> > +++ b/drivers/iio/pressure/Makefile
> > @@ -14,3 +14,7 @@ obj-$(CONFIG_T5403) += t5403.o
> >
> >  obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o
> >  obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o
> > +
>
> alphebetic order?
Fixed
>
> > +obj-$(CONFIG_MS5611) += ms5611_core.o
> > +obj-$(CONFIG_MS5611_I2C) += ms5611_i2c.o
> > +obj-$(CONFIG_MS5611_SPI) += ms5611_spi.o
> > diff --git a/drivers/iio/pressure/ms5611.h b/drivers/iio/pressure/ms5611.h
> > new file mode 100644
> > index 0000000..f4d44a5
> > --- /dev/null
> > +++ b/drivers/iio/pressure/ms5611.h
> > @@ -0,0 +1,44 @@
> > +/*
> > + * 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.
> > + *
> > + */
> > +#ifndef _MS5611_H
> > +#define _MS5611_H
> > +
> > +#include <linux/device.h>
> > +#include <linux/iio/iio.h>
> > +#include <linux/mutex.h>
> > +
> > +#define MS5611_RESET			0x1e
> > +#define MS5611_READ_ADC			0x00
> > +#define MS5611_READ_PROM_WORD		0xA0
> > +#define MS5611_START_TEMP_CONV		0x58
> > +#define MS5611_START_PRESSURE_CONV	0x48
> > +
> > +#define MS5611_CONV_TIME_MIN		9040
> > +#define MS5611_CONV_TIME_MAX		10000
> > +
> > +#define MS5611_PROM_WORDS_NB		8
> > +
> > +struct ms5611_state {
> > +	void *client;
> > +	struct mutex lock;
> > +
> > +	int (*reset)(struct device *dev);
> > +	int (*read_prom_word)(struct device *dev, int index, u16 *word);
> > +	int (*read_adc_temp_and_pressure)(struct device *dev,
> > +					  s32 *temp, s32 *pressure);
> > +
>
> probably regmap could be used to avoid duplicate code?
All communication with this sensor is command based and I don't see
how regmap would fit here.
>
> > +	u16 prom[MS5611_PROM_WORDS_NB];
> > +};
> > +
> > +int ms5611_probe(struct iio_dev *indio_dev, struct device *dev);
> > +int ms5611_remove(struct iio_dev *indio_dev);
> > +
> > +#endif /* _MS5611_H */
> > diff --git a/drivers/iio/pressure/ms5611_core.c b/drivers/iio/pressure/ms5611_core.c
> > new file mode 100644
> > index 0000000..e4deda7
> > --- /dev/null
> > +++ b/drivers/iio/pressure/ms5611_core.c
> > @@ -0,0 +1,239 @@
> > +/*
> > + * 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
> > + *
> > + */
> > +#include <linux/module.h>
> > +#include <linux/iio/iio.h>
> > +#include <linux/delay.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->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->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;
> > +	s32 t, p;
> > +	s64 off, off2, sens, sens2, dt, t2 = 0;
>
> some of the variables could be declared with a more local scope, such as
> tmp below (e.g. sens2)
Fixed
>
> > +	struct ms5611_state *st = iio_priv(indio_dev);
> > +
> > +	ret = st->read_adc_temp_and_pressure(&indio_dev->dev, &t, &p);
> > +	if (ret < 0) {
> > +		dev_err(&indio_dev->dev,
> > +			"failed to read temperature and pressure\n");
> > +		return ret;
> > +	}
> > +
> > +	dt = t - (st->prom[5] << 8);
> > +	off = ((s64)st->prom[2] << 16) + ((st->prom[4] * dt) >> 7);
> > +	sens = ((s64)st->prom[1] << 15) + ((st->prom[3] * dt) >> 8);
> > +
> > +	t = 2000 + ((st->prom[6] * dt) >> 23);
> > +	if (t < 2000) {
> > +		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;
> > +		}
> > +
> > +		off -= off2;
> > +		sens -= sens2;
> > +	}
> > +
> > +	*temp = t - t2;
> > +	*pressure = (((p * sens) >> 21) - off) >> 15;
>
> probably newline here makes it look nicer
OK
>
> > +	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 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)
> > +			break;
> > +
> > +		switch (chan->type) {
> > +		case IIO_TEMP:
> > +			*val = temp;
> > +			ret = IIO_VAL_INT;
> > +			break;
> > +		case IIO_PRESSURE:
> > +			*val = pressure;
> > +			ret = IIO_VAL_INT;
> > +			break;
> > +		default:
> > +			ret = -EINVAL;
>
> probably return -EINVAL directly
OK
>
> > +		}
>
> probably return IIO_VAL_INT here
OK
>
> > +		break;
> > +	case IIO_CHAN_INFO_SCALE:
>
> SCALE is not necessary when _PROCESSED is already doing all the scaling
> such that the output is in milli-Celsius and kilo-Pascal
OK. Thanks for clarifying this.
>
> > +		switch (chan->type) {
> > +		case IIO_TEMP:
> > +			*val = 0;
> > +			*val2 = 10000;
> > +			ret = IIO_VAL_INT_PLUS_MICRO;
> > +			break;
> > +		case IIO_PRESSURE:
> > +			*val = 0;
> > +			*val2 = 1000;
> > +			ret = IIO_VAL_INT_PLUS_MICRO;
> > +			break;
> > +		default:
> > +			ret = -EINVAL;
> > +		}
> > +		break;
> > +	default:
> > +		ret = -EINVAL;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static const struct iio_chan_spec ms5611_channels[] = {
> > +	{
> > +		.type = IIO_PRESSURE,
> > +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> > +			BIT(IIO_CHAN_INFO_SCALE)
> > +	},
> > +	{
> > +		.type = IIO_TEMP,
> > +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> > +			BIT(IIO_CHAN_INFO_SCALE)
> > +	}
> > +};
> > +
> > +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;
> > +
> > +	ret = ms5611_reset(indio_dev);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	ret = ms5611_read_prom(indio_dev);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	return 0;
> > +}
> > +
> > +int ms5611_probe(struct iio_dev *indio_dev, struct device *dev)
> > +{
> > +	int ret;
> > +	struct ms5611_state *st = iio_priv(indio_dev);
> > +
> > +	mutex_init(&st->lock);
> > +	indio_dev->dev.parent = dev;
> > +	indio_dev->name = dev->driver->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;
> > +
> > +	ret = ms5611_init(indio_dev);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	return iio_device_register(indio_dev);
>
> use devm_iio_device_register() and save _remove()
OK
>
> > +}
> > +EXPORT_SYMBOL(ms5611_probe);
> > +
> > +int ms5611_remove(struct iio_dev *indio_dev)
> > +{
> > +	iio_device_unregister(indio_dev);
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(ms5611_remove);
> > +
> > +MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
> > +MODULE_DESCRIPTION("MS5611 core driver");
> > +MODULE_LICENSE("GPL v2");
> > diff --git a/drivers/iio/pressure/ms5611_i2c.c b/drivers/iio/pressure/ms5611_i2c.c
> > new file mode 100644
> > index 0000000..920fa78
> > --- /dev/null
> > +++ b/drivers/iio/pressure/ms5611_i2c.c
> > @@ -0,0 +1,131 @@
> > +/*
> > + * MS5611 pressure and temperature sensor driver (I2C bus)
> > + *
> > + * 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.
> > + *
> > + */
> > +#include <linux/delay.h>
> > +#include <linux/i2c.h>
> > +#include <linux/module.h>
> > +
> > +#include "ms5611.h"
> > +
> > +static int ms5611_reset(struct device *dev)
> > +{
> > +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> > +
> > +	return i2c_smbus_write_byte(st->client, MS5611_RESET);
> > +}
> > +
> > +static int ms5611_read_prom_word(struct device *dev, int index, u16 *word)
> > +{
> > +	int ret;
> > +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> > +
> > +	ret = i2c_smbus_read_word_swapped(st->client,
> > +			MS5611_READ_PROM_WORD + (index << 1));
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	*word = ret;
> > +	return 0;
> > +}
> > +
> > +static int ms5611_read_adc(struct ms5611_state *st, s32 *val)
> > +{
> > +	int ret;
> > +	u8 buf[3];
> > +
> > +	ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
> > +					    3, buf);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	*val = (buf[0] << 16) | (buf[1] << 8) | buf[0];
>
> should be buf[2] at the end
You are right.
>
> > +	return 0;
> > +}
> > +
> > +static int ms5611_read_adc_temp_and_pressure(struct device *dev,
> > +					     s32 *temp, s32 *pressure)
> > +{
> > +	int ret;
> > +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> > +
> > +	ret = i2c_smbus_write_byte(st->client, MS5611_START_TEMP_CONV);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
> > +
> > +	ret = ms5611_read_adc(st, temp);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	ret = i2c_smbus_write_byte(st->client, MS5611_START_PRESSURE_CONV);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
> > +
> > +	ret = ms5611_read_adc(st, pressure);
> > +	if (ret < 0)
> > +		return ret;
>
> just return ret?
OK
>
> > +
> > +	return 0;
> > +}
> > +
> > +static int ms5611_i2c_probe(struct i2c_client *client,
> > +			    const struct i2c_device_id *id)
> > +{
> > +	struct ms5611_state *st;
> > +	struct iio_dev *indio_dev;
> > +
> > +	if (!i2c_check_functionality(client->adapter,
> > +				     I2C_FUNC_SMBUS_WRITE_BYTE |
> > +				     I2C_FUNC_SMBUS_READ_WORD_DATA |
> > +				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
> > +		return -ENODEV;
> > +
> > +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
> > +	if (!indio_dev)
> > +		return -ENOMEM;
> > +
> > +	i2c_set_clientdata(client, indio_dev);
> > +	st = iio_priv(indio_dev);
> > +	st->reset = ms5611_reset;
> > +	st->read_prom_word = ms5611_read_prom_word;
> > +	st->read_adc_temp_and_pressure = ms5611_read_adc_temp_and_pressure;
> > +	st->client = client;
> > +
> > +	return ms5611_probe(indio_dev, &client->dev);
> > +}
> > +
> > +static int ms5611_i2c_remove(struct i2c_client *client)
> > +{
> > +	return ms5611_remove(i2c_get_clientdata(client));
> > +}
> > +
> > +static const struct i2c_device_id ms5611_id[] = {
> > +	{ "ms5611", 0 },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(i2c, ms5611_id);
> > +
> > +static struct i2c_driver ms5611_driver = {
> > +	.driver = {
> > +		.name = "ms5611",
> > +		.owner = THIS_MODULE,
> > +	},
> > +	.id_table = ms5611_id,
> > +	.probe = ms5611_i2c_probe,
> > +	.remove = ms5611_i2c_remove,
> > +};
> > +module_i2c_driver(ms5611_driver);
> > +
> > +MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
> > +MODULE_DESCRIPTION("MS5611 i2c driver");
> > +MODULE_LICENSE("GPL v2");
> > diff --git a/drivers/iio/pressure/ms5611_spi.c b/drivers/iio/pressure/ms5611_spi.c
> > new file mode 100644
> > index 0000000..eb3fee5
> > --- /dev/null
> > +++ b/drivers/iio/pressure/ms5611_spi.c
> > @@ -0,0 +1,137 @@
> > +/*
> > + * MS5611 pressure and temperature sensor driver (SPI bus)
> > + *
> > + * 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.
> > + *
> > + */
> > +#include <linux/delay.h>
> > +#include <linux/module.h>
> > +#include <linux/spi/spi.h>
> > +
> > +#include "ms5611.h"
> > +
> > +static int ms5611_reset(struct device *dev)
> > +{
> > +	u8 cmd = MS5611_RESET;
> > +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> > +
> > +	return spi_write(st->client, &cmd, 1);
> > +}
> > +
> > +static int ms5611_read_prom_word(struct device *dev, int index, u16 *word)
> > +{
> > +	int ret;
> > +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> > +
> > +	ret = spi_w8r16be(st->client, MS5611_READ_PROM_WORD + (index << 1));
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	*word = ret;
> > +	return 0;
> > +}
> > +
> > +static int ms5611_read_adc(struct device *dev, s32 *val)
> > +{
> > +	int ret;
> > +	u8 buf[3];
> > +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> > +
> > +	buf[0] = MS5611_READ_ADC;
> > +
> > +	ret = spi_write_then_read(st->client, buf, 1, buf, 3);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	*val = (buf[0] << 16) | (buf[1] << 8) | buf[0];
>
> buf[2]?
Right, typo here.
>
> > +	return 0;
> > +}
> > +
> > +static int ms5611_read_adc_temp_and_pressure(struct device *dev,
> > +					     s32 *temp, s32 *pressure)
> > +{
> > +	u8 cmd;
> > +	int ret;
> > +	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
> > +
> > +	cmd = MS5611_START_TEMP_CONV;
> > +	ret = spi_write(st->client, &cmd, 1);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
> > +
> > +	ret = ms5611_read_adc(dev, temp);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	cmd = MS5611_START_PRESSURE_CONV;
> > +	ret = spi_write(st->client, &cmd, 1);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
> > +
> > +	ret = ms5611_read_adc(dev, pressure);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	return 0;
> > +}
> > +
> > +static int ms5611_spi_probe(struct spi_device *spi)
> > +{
> > +	int ret;
> > +	struct ms5611_state *st;
> > +	struct iio_dev *indio_dev;
> > +
> > +	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> > +	if (!indio_dev)
> > +		return -ENOMEM;
> > +
> > +	spi->mode = SPI_MODE_0;
> > +	spi->max_speed_hz = 20000000;
> > +	spi->bits_per_word = 8;
> > +	ret = spi_setup(spi);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	spi_set_drvdata(spi, indio_dev);
> > +	st = iio_priv(indio_dev);
> > +	st->reset = ms5611_reset;
> > +	st->read_prom_word = ms5611_read_prom_word;
> > +	st->read_adc_temp_and_pressure = ms5611_read_adc_temp_and_pressure;
> > +	st->client = spi;
> > +
> > +	return ms5611_probe(indio_dev, &spi->dev);
> > +}
> > +
> > +static int ms5611_spi_remove(struct spi_device *spi)
> > +{
> > +	return ms5611_remove(spi_get_drvdata(spi));
> > +}
> > +
> > +static const struct spi_device_id ms5611_id[] = {
> > +	{ "ms5611", 0 },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(spi, ms5611_id);
> > +
> > +static struct spi_driver ms5611_driver = {
> > +	.driver = {
> > +		.name = "ms5611",
> > +		.owner = THIS_MODULE,
> > +	},
> > +	.id_table = ms5611_id,
> > +	.probe = ms5611_spi_probe,
> > +	.remove = ms5611_spi_remove,
> > +};
> > +module_spi_driver(ms5611_driver);
> > +
> > +MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
> > +MODULE_DESCRIPTION("MS5611 spi driver");
> > +MODULE_LICENSE("GPL v2");
> >
>
> --
>
> Peter Meerwald
> +43-664-2444418 (mobile)

Thanks for review!

Re: [PATCH] iio: pressure: add support for MS5611 pressure and temperature sensor

[tduszyns]

On Sun, Mar 08, 2015 at 09:11:07PM +0200, Daniel Baluta wrote:
> Hi Tomasz,
>
> On Sun, Mar 8, 2015 at 7:29 PM, Tomasz Duszynski <tduszyns@gmail.com> wrote:
> > Add support for Measurement Specialities MS5611 pressure
> > and temperature sensor.
> >
> > Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
>
> <snip>
>
> > +++ b/drivers/iio/pressure/ms5611_i2c.c
> > @@ -0,0 +1,131 @@
> > +/*
> > + * MS5611 pressure and temperature sensor driver (I2C bus)
> > + *
> > + * 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.
> > + *
>
> If fixed, please specify here the I2C slave address.
OK
>
> > + */
> > +#include <linux/delay.h>
>
> <snip>
>
> > +static int ms5611_read_adc(struct ms5611_state *st, s32 *val)
> > +{
> > +       int ret;
> > +       u8 buf[3];
> > +
> > +       ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
> > +                                           3, buf);
> > +       if (ret < 0)
> > +               return ret;
> > +
> > +       *val = (buf[0] << 16) | (buf[1] << 8) | buf[0];
>
> Hmm, buf[2] is not used. Is this intended or the formula
> has buf[2] as the last OR factor?
You're right. Last factor should be buf[2].
>
> thanks,
> Daniel.

Thanks for review!