Re: [PATCH v4 2/7] Add tsys01 meas-spec driver support

[Jonathan Cameron <jic23@kernel.org>]

On 01/10/15 15:13, Ludovic Tancerel wrote:
> Support for TSYS01 temperature sensor
> 
> Signed-off-by: Ludovic Tancerel <ludovic.tancerel@maplehightech.com>
Applied.
> ---
>  drivers/iio/temperature/Kconfig  |  11 ++
>  drivers/iio/temperature/Makefile |   1 +
>  drivers/iio/temperature/tsys01.c | 230 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 242 insertions(+)
>  create mode 100644 drivers/iio/temperature/tsys01.c
> 
> diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
> index 21feaa4..35712032 100644
> --- a/drivers/iio/temperature/Kconfig
> +++ b/drivers/iio/temperature/Kconfig
> @@ -23,4 +23,15 @@ config TMP006
>  	  This driver can also be built as a module. If so, the module will
>  	  be called tmp006.
>  
> +config TSYS01
> +	tristate "Measurement Specialties TSYS01 temperature sensor using I2C bus connection"
> +	depends on I2C
> +	select IIO_MS_SENSORS_I2C
> +	help
> +	  If you say yes here you get support for the Measurement Specialties
> +	  TSYS01 I2C temperature sensor.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called tsys01.
> +
>  endmenu
> diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
> index 40710a8..368a2a2 100644
> --- a/drivers/iio/temperature/Makefile
> +++ b/drivers/iio/temperature/Makefile
> @@ -4,3 +4,4 @@
>  
>  obj-$(CONFIG_MLX90614) += mlx90614.o
>  obj-$(CONFIG_TMP006) += tmp006.o
> +obj-$(CONFIG_TSYS01) += tsys01.o
> diff --git a/drivers/iio/temperature/tsys01.c b/drivers/iio/temperature/tsys01.c
> new file mode 100644
> index 0000000..05c1206
> --- /dev/null
> +++ b/drivers/iio/temperature/tsys01.c
> @@ -0,0 +1,230 @@
> +/*
> + * tsys01.c - Support for Measurement-Specialties tsys01 temperature sensor
> + *
> + * Copyright (c) 2015 Measurement-Specialties
> + *
> + * Licensed under the GPL-2.
> + *
> + * Datasheet:
> + *  http://www.meas-spec.com/downloads/TSYS01_Digital_Temperature_Sensor.pdf
> + */
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/device.h>
> +#include <linux/mutex.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/stat.h>
> +#include "../common/ms_sensors/ms_sensors_i2c.h"
> +
> +/* TSYS01 Commands */
> +#define TSYS01_RESET				0x1E
> +#define TSYS01_CONVERSION_START			0x48
> +#define TSYS01_ADC_READ				0x00
> +#define TSYS01_PROM_READ			0xA0
> +
> +#define TSYS01_PROM_WORDS_NB			8
> +
> +struct tsys01_dev {
> +	void *client;
> +	struct mutex lock; /* lock during conversion */
> +
> +	int (*reset)(void *cli, u8 cmd, unsigned int delay);
> +	int (*convert_and_read)(void *cli, u8 conv, u8 rd,
> +				unsigned int delay, u32 *adc);
> +	int (*read_prom_word)(void *cli, int cmd, u16 *word);
> +
> +	u16 prom[TSYS01_PROM_WORDS_NB];
> +};
> +
> +/* Multiplication coefficients for temperature computation */
> +static const int coeff_mul[] = { -1500000, 1000000, -2000000,
> +				 4000000, -2000000 };
> +
> +static int tsys01_read_temperature(struct iio_dev *indio_dev,
> +				   s32 *temperature)
> +{
> +	int ret, i;
> +	u32 adc;
> +	s64 temp = 0;
> +	struct tsys01_dev *dev_data = iio_priv(indio_dev);
> +
> +	mutex_lock(&dev_data->lock);
> +	ret = dev_data->convert_and_read(dev_data->client,
> +					 TSYS01_CONVERSION_START,
> +					 TSYS01_ADC_READ, 9000, &adc);
> +	mutex_unlock(&dev_data->lock);
> +	if (ret)
> +		return ret;
> +
> +	adc >>= 8;
> +
> +	/* Temperature algorithm */
> +	for (i = 4; i > 0; i--) {
> +		temp += coeff_mul[i] *
> +			(s64)dev_data->prom[5 - i];
> +		temp *= (s64)adc;
> +		temp = div64_s64(temp, 100000);
> +	}
> +	temp *= 10;
> +	temp += coeff_mul[0] * (s64)dev_data->prom[5];
> +	temp = div64_s64(temp, 100000);
> +
> +	*temperature = temp;
> +
> +	return 0;
> +}
> +
> +static int tsys01_read_raw(struct iio_dev *indio_dev,
> +			   struct iio_chan_spec const *channel, int *val,
> +			   int *val2, long mask)
> +{
> +	int ret;
> +	s32 temperature;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_PROCESSED:
> +		switch (channel->type) {
> +		case IIO_TEMP:	/* in milli °C */
> +			ret = tsys01_read_temperature(indio_dev, &temperature);
> +			if (ret)
> +				return ret;
> +			*val = temperature;
> +
> +			return IIO_VAL_INT;
> +		default:
> +			return -EINVAL;
> +		}
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static const struct iio_chan_spec tsys01_channels[] = {
> +	{
> +		.type = IIO_TEMP,
> +		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
> +	}
> +};
> +
> +static const struct iio_info tsys01_info = {
> +	.read_raw = tsys01_read_raw,
> +	.driver_module = THIS_MODULE,
> +};
> +
> +static bool tsys01_crc_valid(u16 *n_prom)
> +{
> +	u8 cnt;
> +	u8 sum = 0;
> +
> +	for (cnt = 0; cnt < TSYS01_PROM_WORDS_NB; cnt++)
> +		sum += ((n_prom[0] >> 8) + (n_prom[0] & 0xFF));
> +
> +	return (sum == 0);
> +}
> +
> +static int tsys01_read_prom(struct iio_dev *indio_dev)
> +{
> +	int i, ret;
> +	struct tsys01_dev *dev_data = iio_priv(indio_dev);
> +	char buf[7 * TSYS01_PROM_WORDS_NB + 1];
> +	char *ptr = buf;
> +
> +	for (i = 0; i < TSYS01_PROM_WORDS_NB; i++) {
> +		ret = dev_data->read_prom_word(dev_data->client,
> +					       TSYS01_PROM_READ + (i << 1),
> +					       &dev_data->prom[i]);
> +		if (ret)
> +			return ret;
> +
> +		ret = sprintf(ptr, "0x%04x ", dev_data->prom[i]);
> +		ptr += ret;
> +	}
> +
> +	if (!tsys01_crc_valid(dev_data->prom)) {
> +		dev_err(&indio_dev->dev, "prom crc check error\n");
> +		return -ENODEV;
> +	}
> +	*ptr = 0;
> +	dev_info(&indio_dev->dev, "PROM coefficients : %s\n", buf);
> +
> +	return 0;
> +}
> +
> +static int tsys01_probe(struct iio_dev *indio_dev, struct device *dev)
> +{
> +	int ret;
> +	struct tsys01_dev *dev_data = iio_priv(indio_dev);
> +
> +	mutex_init(&dev_data->lock);
> +
> +	indio_dev->info = &tsys01_info;
> +	indio_dev->name = dev->driver->name;
> +	indio_dev->dev.parent = dev;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = tsys01_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(tsys01_channels);
> +
> +	ret = dev_data->reset(dev_data->client, TSYS01_RESET, 3000);
> +	if (ret)
> +		return ret;
> +
> +	ret = tsys01_read_prom(indio_dev);
> +	if (ret)
> +		return ret;
> +
> +	return devm_iio_device_register(dev, indio_dev);
> +}
> +
> +static int tsys01_i2c_probe(struct i2c_client *client,
> +			    const struct i2c_device_id *id)
> +{
> +	struct tsys01_dev *dev_data;
> +	struct iio_dev *indio_dev;
> +
> +	if (!i2c_check_functionality(client->adapter,
> +				     I2C_FUNC_SMBUS_WORD_DATA |
> +				     I2C_FUNC_SMBUS_WRITE_BYTE |
> +				     I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
> +		dev_err(&client->dev,
> +			"Adapter does not support some i2c transaction\n");
> +		return -ENODEV;
> +	}
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	dev_data = iio_priv(indio_dev);
> +	dev_data->client = client;
> +	dev_data->reset = ms_sensors_reset;
> +	dev_data->read_prom_word = ms_sensors_read_prom_word;
> +	dev_data->convert_and_read = ms_sensors_convert_and_read;
> +
> +	i2c_set_clientdata(client, indio_dev);
> +
> +	return tsys01_probe(indio_dev, &client->dev);
> +}
> +
> +static const struct i2c_device_id tsys01_id[] = {
> +	{"tsys01", 0},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, tsys01_id);
> +
> +static struct i2c_driver tsys01_driver = {
> +	.probe = tsys01_i2c_probe,
> +	.id_table = tsys01_id,
> +	.driver = {
> +		   .name = "tsys01",
> +		   },
> +};
> +
> +module_i2c_driver(tsys01_driver);
> +
> +MODULE_DESCRIPTION("Measurement-Specialties tsys01 temperature driver");
> +MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
> +MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
> +MODULE_LICENSE("GPL v2");
>