Re: [PATCH v2] iio: Add t5403 barometric pressure sensor driver

[Jonathan Cameron <jic23@kernel.org>]

On 14/06/14 12:47, Hartmut Knaack wrote:
> Peter Meerwald schrieb:
>> 16-bit pressure and temperature sensor
>>
>> the chip can do I2C and SPI, only the I2C interface is supported
>> by the driver at the moment
>>
>> datasheet: http://www.epcos.com/inf/57/ds/T5400.pdf
>> application note: http://www.epcos.com/blob/993154/download/1/t5403-applicationnote.pdf
>>
>> an out-of-tree driver targetting the input subsystem is at
>> https://github.com/unixphere/t5400, it was rejected here:
>> http://comments.gmane.org/gmane.linux.kernel.input/28107
>>
>> v2: (thanks Hartmut Knaack)
>> * fix MODE_HIGH, equals 2
>> * check INT_TIME mask in write_raw()
>>
>> Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
>> Cc: Stefan Nilsson <stefan.nilsson@unixphere.com>
> Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>
> Looks good to me.
Thanks Hartmut,

Applied to the togreg branch of iio.git.  Will be pushing this out
as testing initially to let the autobuilders play.

Jonathan
>> ---
>>   drivers/iio/pressure/Kconfig  |  10 ++
>>   drivers/iio/pressure/Makefile |   1 +
>>   drivers/iio/pressure/t5403.c  | 275 ++++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 286 insertions(+)
>>   create mode 100644 drivers/iio/pressure/t5403.c
>>
>> diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
>> index ffac8ac..15afbc9 100644
>> --- a/drivers/iio/pressure/Kconfig
>> +++ b/drivers/iio/pressure/Kconfig
>> @@ -70,4 +70,14 @@ config IIO_ST_PRESS_SPI
>>   	depends on IIO_ST_PRESS
>>   	depends on IIO_ST_SENSORS_SPI
>>
>> +config T5403
>> +	tristate "EPCOS T5403 digital barometric pressure sensor driver"
>> +	depends on I2C
>> +	help
>> +	  Say yes here to build support for the EPCOS T5403 pressure sensor
>> +	  connected via I2C.
>> +
>> +          To compile this driver as a module, choose M here: the module
>> +          will be called t5403.
>> +
>>   endmenu
>> diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile
>> index c53d250..90a37e8 100644
>> --- a/drivers/iio/pressure/Makefile
>> +++ b/drivers/iio/pressure/Makefile
>> @@ -9,6 +9,7 @@ obj-$(CONFIG_MPL3115) += mpl3115.o
>>   obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o
>>   st_pressure-y := st_pressure_core.o
>>   st_pressure-$(CONFIG_IIO_BUFFER) += st_pressure_buffer.o
>> +obj-$(CONFIG_T5403) += t5403.o
>>
>>   obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o
>>   obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o
>> diff --git a/drivers/iio/pressure/t5403.c b/drivers/iio/pressure/t5403.c
>> new file mode 100644
>> index 0000000..e11cd39
>> --- /dev/null
>> +++ b/drivers/iio/pressure/t5403.c
>> @@ -0,0 +1,275 @@
>> +/*
>> + * t5403.c - Support for EPCOS T5403 pressure/temperature sensor
>> + *
>> + * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
>> + *
>> + * This file is subject to the terms and conditions of version 2 of
>> + * the GNU General Public License.  See the file COPYING in the main
>> + * directory of this archive for more details.
>> + *
>> + * (7-bit I2C slave address 0x77)
>> + *
>> + * TODO: end-of-conversion irq
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/i2c.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/sysfs.h>
>> +#include <linux/delay.h>
>> +
>> +#define T5403_DATA 0xf5 /* data, LSB first, 16 bit */
>> +#define T5403_CALIB_DATA 0x8e /* 10 calibration coeff., LSB first, 16 bit */
>> +#define T5403_SLAVE_ADDR 0x88 /* I2C slave address, 0x77 */
>> +#define T5403_COMMAND 0xf1
>> +
>> +/* command bits */
>> +#define T5403_MODE_SHIFT 3 /* conversion time: 2, 8, 16, 66 ms */
>> +#define T5403_PT BIT(1) /* 0 .. pressure, 1 .. temperature measurement */
>> +#define T5403_SCO BIT(0) /* start conversion */
>> +
>> +#define T5403_MODE_LOW 0
>> +#define T5403_MODE_STANDARD 1
>> +#define T5403_MODE_HIGH 2
>> +#define T5403_MODE_ULTRA_HIGH 3
>> +
>> +#define T5403_I2C_MASK (~BIT(7))
>> +#define T5403_I2C_ADDR 0x77
>> +
>> +static const int t5403_pressure_conv_ms[] = {2, 8, 16, 66};
>> +
>> +struct t5403_data {
>> +	struct i2c_client *client;
>> +	struct mutex lock;
>> +	int mode;
>> +	__le16 c[10];
>> +};
>> +
>> +#define T5403_C_U16(i) le16_to_cpu(data->c[(i) - 1])
>> +#define T5403_C(i) sign_extend32(T5403_C_U16(i), 15)
>> +
>> +static int t5403_read(struct t5403_data *data, bool pressure)
>> +{
>> +	int wait_time = 3;  /* wakeup time in ms */
>> +
>> +	int ret = i2c_smbus_write_byte_data(data->client, T5403_COMMAND,
>> +		(pressure ? (data->mode << T5403_MODE_SHIFT) : T5403_PT) |
>> +		T5403_SCO);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	wait_time += pressure ? t5403_pressure_conv_ms[data->mode] : 2;
>> +
>> +	msleep(wait_time);
>> +
>> +	return i2c_smbus_read_word_data(data->client, T5403_DATA);
>> +}
>> +
>> +static int t5403_comp_pressure(struct t5403_data *data, int *val, int *val2)
>> +{
>> +	int ret;
>> +	s16 t_r;
>> +	u16 p_r;
>> +	s32 S, O, X;
>> +
>> +	mutex_lock(&data->lock);
>> +
>> +	ret = t5403_read(data, false);
>> +	if (ret < 0)
>> +		goto done;
>> +	t_r = ret;
>> +
>> +	ret = t5403_read(data, true);
>> +	if (ret < 0)
>> +		goto done;
>> +	p_r = ret;
>> +
>> +	/* see EPCOS application note */
>> +	S = T5403_C_U16(3) + (s32) T5403_C_U16(4) * t_r / 0x20000 +
>> +		T5403_C(5) * t_r / 0x8000 * t_r / 0x80000 +
>> +		T5403_C(9) * t_r / 0x8000 * t_r / 0x8000 * t_r / 0x10000;
>> +
>> +	O = T5403_C(6) * 0x4000 + T5403_C(7) * t_r / 8 +
>> +		T5403_C(8) * t_r / 0x8000 * t_r / 16 +
>> +		T5403_C(9) * t_r / 0x8000 * t_r / 0x10000 * t_r;
>> +
>> +	X = (S * p_r + O) / 0x4000;
>> +
>> +	X += ((X - 75000) * (X - 75000) / 0x10000 - 9537) *
>> +	    T5403_C(10) / 0x10000;
>> +
>> +	*val = X / 1000;
>> +	*val2 = (X % 1000) * 1000;
>> +
>> +done:
>> +	mutex_unlock(&data->lock);
>> +	return ret;
>> +}
>> +
>> +static int t5403_comp_temp(struct t5403_data *data, int *val)
>> +{
>> +	int ret;
>> +	s16 t_r;
>> +
>> +	mutex_lock(&data->lock);
>> +	ret = t5403_read(data, false);
>> +	if (ret < 0)
>> +		goto done;
>> +	t_r = ret;
>> +
>> +	/* see EPCOS application note */
>> +	*val = ((s32) T5403_C_U16(1) * t_r / 0x100 +
>> +		(s32) T5403_C_U16(2) * 0x40) * 1000 / 0x10000;
>> +
>> +done:
>> +	mutex_unlock(&data->lock);
>> +	return ret;
>> +}
>> +
>> +static int t5403_read_raw(struct iio_dev *indio_dev,
>> +			  struct iio_chan_spec const *chan,
>> +			  int *val, int *val2, long mask)
>> +{
>> +	struct t5403_data *data = iio_priv(indio_dev);
>> +	int ret;
>> +
>> +	switch (mask) {
>> +	case IIO_CHAN_INFO_PROCESSED:
>> +		switch (chan->type) {
>> +		case IIO_PRESSURE:
>> +			ret = t5403_comp_pressure(data, val, val2);
>> +			if (ret < 0)
>> +				return ret;
>> +			return IIO_VAL_INT_PLUS_MICRO;
>> +		case IIO_TEMP:
>> +			ret = t5403_comp_temp(data, val);
>> +			if (ret < 0)
>> +				return ret;
>> +			return IIO_VAL_INT;
>> +		default:
>> +			return -EINVAL;
>> +	    }
>> +	case IIO_CHAN_INFO_INT_TIME:
>> +		*val = 0;
>> +		*val2 = t5403_pressure_conv_ms[data->mode] * 1000;
>> +		return IIO_VAL_INT_PLUS_MICRO;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +}
>> +
>> +static int t5403_write_raw(struct iio_dev *indio_dev,
>> +			   struct iio_chan_spec const *chan,
>> +			   int val, int val2, long mask)
>> +{
>> +	struct t5403_data *data = iio_priv(indio_dev);
>> +	int i;
>> +
>> +	switch (mask) {
>> +	case IIO_CHAN_INFO_INT_TIME:
>> +		if (val != 0)
>> +			return -EINVAL;
>> +		for (i = 0; i < ARRAY_SIZE(t5403_pressure_conv_ms); i++)
>> +			if (val2 == t5403_pressure_conv_ms[i] * 1000) {
>> +				mutex_lock(&data->lock);
>> +				data->mode = i;
>> +				mutex_unlock(&data->lock);
>> +				return 0;
>> +			}
>> +		return -EINVAL;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +}
>> +
>> +static const struct iio_chan_spec t5403_channels[] = {
>> +	{
>> +		.type = IIO_PRESSURE,
>> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
>> +		    BIT(IIO_CHAN_INFO_INT_TIME),
>> +	},
>> +	{
>> +		.type = IIO_TEMP,
>> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
>> +	},
>> +};
>> +
>> +static IIO_CONST_ATTR_INT_TIME_AVAIL("0.002 0.008 0.016 0.066");
>> +
>> +static struct attribute *t5403_attributes[] = {
>> +	&iio_const_attr_integration_time_available.dev_attr.attr,
>> +	NULL
>> +};
>> +
>> +static const struct attribute_group t5403_attribute_group = {
>> +	.attrs = t5403_attributes,
>> +};
>> +
>> +static const struct iio_info t5403_info = {
>> +	.read_raw = &t5403_read_raw,
>> +	.write_raw = &t5403_write_raw,
>> +	.attrs = &t5403_attribute_group,
>> +	.driver_module = THIS_MODULE,
>> +};
>> +
>> +static int t5403_probe(struct i2c_client *client,
>> +			 const struct i2c_device_id *id)
>> +{
>> +	struct t5403_data *data;
>> +	struct iio_dev *indio_dev;
>> +	int ret;
>> +
>> +	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
>> +	    I2C_FUNC_SMBUS_I2C_BLOCK))
>> +		return -ENODEV;
>> +
>> +	ret = i2c_smbus_read_byte_data(client, T5403_SLAVE_ADDR);
>> +	if (ret < 0)
>> +		return ret;
>> +	if ((ret & T5403_I2C_MASK) != T5403_I2C_ADDR)
>> +		return -ENODEV;
>> +
>> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>> +	if (!indio_dev)
>> +		return -ENOMEM;
>> +
>> +	data = iio_priv(indio_dev);
>> +	data->client = client;
>> +	mutex_init(&data->lock);
>> +
>> +	i2c_set_clientdata(client, indio_dev);
>> +	indio_dev->info = &t5403_info;
>> +	indio_dev->name = id->name;
>> +	indio_dev->dev.parent = &client->dev;
>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>> +	indio_dev->channels = t5403_channels;
>> +	indio_dev->num_channels = ARRAY_SIZE(t5403_channels);
>> +
>> +	data->mode = T5403_MODE_STANDARD;
>> +
>> +	ret = i2c_smbus_read_i2c_block_data(data->client, T5403_CALIB_DATA,
>> +	    sizeof(data->c), (u8 *) data->c);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	return devm_iio_device_register(&client->dev, indio_dev);
>> +}
>> +
>> +static const struct i2c_device_id t5403_id[] = {
>> +	{ "t5403", 0 },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(i2c, t5403_id);
>> +
>> +static struct i2c_driver t5403_driver = {
>> +	.driver = {
>> +		.name	= "t5403",
>> +	},
>> +	.probe = t5403_probe,
>> +	.id_table = t5403_id,
>> +};
>> +module_i2c_driver(t5403_driver);
>> +
>> +MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
>> +MODULE_DESCRIPTION("EPCOS T5403 pressure/temperature sensor driver");
>> +MODULE_LICENSE("GPL");
>