Re: [PATCH 2/2] iio: chemical: atlas-ph-sensor: add EC feature

[Jonathan Cameron <jic23@kernel.org>]

On 24/04/16 21:43, Matt Ranostay wrote:
Give us a bit more description - what is it, what is it for, what interface is
supplied. Err what does EC standard for?
> Signed-off-by: Matt Ranostay <mranostay@gmail.com>
I know next to nothing about these sensors and don't have the datasheet to hand.

This is measuring 3 different types of concentration (I think) and reporting them
simple as channels 0-2.  What are they are should we not be distinguishing between
them in some more informative fashion?

Code itself is mostly fine...

Jonathan
> ---
>  .../bindings/iio/chemical/atlas,ec-sm.txt          |  22 ++++
>  drivers/iio/chemical/Kconfig                       |   8 +-
>  drivers/iio/chemical/atlas-ph-sensor.c             | 113 ++++++++++++++++++++-
>  3 files changed, 138 insertions(+), 5 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/iio/chemical/atlas,ec-sm.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/chemical/atlas,ec-sm.txt b/Documentation/devicetree/bindings/iio/chemical/atlas,ec-sm.txt
> new file mode 100644
> index 0000000..2962bd9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/chemical/atlas,ec-sm.txt
> @@ -0,0 +1,22 @@
> +* Atlas Scientific EC-SM OEM sensor
> +
> +http://www.atlas-scientific.com/_files/_datasheets/_oem/EC_oem_datasheet.pdf
> +
> +Required properties:
> +
> +  - compatible: must be "atlas,ec-sm"
> +  - reg: the I2C address of the sensor
> +  - interrupt-parent: should be the phandle for the interrupt controller
> +  - interrupts: the sole interrupt generated by the device
> +
> +  Refer to interrupt-controller/interrupts.txt for generic interrupt client
> +  node bindings.
> +
> +Example:
> +
> +atlas@64 {
> +	compatible = "atlas,ec-sm";
> +	reg = <0x64>;
> +	interrupt-parent = <&gpio1>;
> +	interrupts = <16 2>;
> +};
> diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
> index f73290f..4bcc025 100644
> --- a/drivers/iio/chemical/Kconfig
> +++ b/drivers/iio/chemical/Kconfig
> @@ -5,15 +5,17 @@
>  menu "Chemical Sensors"
>  
>  config ATLAS_PH_SENSOR
> -	tristate "Atlas Scientific OEM pH-SM sensor"
> +	tristate "Atlas Scientific OEM SM sensors"
>  	depends on I2C
>  	select REGMAP_I2C
>  	select IIO_BUFFER
>  	select IIO_TRIGGERED_BUFFER
>  	select IRQ_WORK
>  	help
> -	 Say Y here to build I2C interface support for the Atlas
> -	 Scientific OEM pH-SM sensor.
> +	 Say Y here to build I2C interface support for the following
> +	 Atlas Scientific OEM SM sensors:
> +	    * pH SM sensor
> +	    * EC SM sensor
>  
>  	 To compile this driver as module, choose M here: the
>  	 module will be called atlas-ph-sensor.
> diff --git a/drivers/iio/chemical/atlas-ph-sensor.c b/drivers/iio/chemical/atlas-ph-sensor.c
> index c57f9c2..6dddd75 100644
> --- a/drivers/iio/chemical/atlas-ph-sensor.c
> +++ b/drivers/iio/chemical/atlas-ph-sensor.c
> @@ -50,13 +50,28 @@
>  #define ATLAS_REG_PH_CALIB_STATUS_MID	BIT(1)
>  #define ATLAS_REG_PH_CALIB_STATUS_HIGH	BIT(2)
>  
> +#define ATLAS_REG_EC_CALIB_STATUS		0x0f
> +#define ATLAS_REG_EC_CALIB_STATUS_MASK		0x0f
> +#define ATLAS_REG_EC_CALIB_STATUS_DRY		BIT(0)
> +#define ATLAS_REG_EC_CALIB_STATUS_SINGLE	BIT(1)
> +#define ATLAS_REG_EC_CALIB_STATUS_LOW		BIT(2)
> +#define ATLAS_REG_EC_CALIB_STATUS_HIGH		BIT(3)
> +
>  #define ATLAS_REG_PH_TEMP_DATA		0x0e
>  #define ATLAS_REG_PH_DATA		0x16
>  
> +#define ATLAS_REG_EC_PROBE		0x08
> +#define ATLAS_REG_EC_TEMP_DATA		0x10
> +#define ATLAS_REG_EC_DATA		0x18
> +#define ATLAS_REG_TDS_DATA		0x1c
> +#define ATLAS_REG_PSS_DATA		0x20
> +
>  #define ATLAS_PH_INT_TIME_IN_US		450000
> +#define ATLAS_EC_INT_TIME_IN_US		650000
>  
>  enum {
>  	ATLAS_PH_SM,
> +	ATLAS_EC_SM,
>  };
>  
>  struct atlas_data {
> @@ -66,12 +81,13 @@ struct atlas_data {
>  	struct regmap *regmap;
>  	struct irq_work work;
>  
> -	__be32 buffer[4]; /* 32-bit pH data + 32-bit pad + 64-bit timestamp */
> +	__be32 buffer[6]; /* 96-bit data + 32-bit pad + 64-bit timestamp */
>  };
>  
>  static const struct regmap_range atlas_volatile_ranges[] = {
>  	regmap_reg_range(ATLAS_REG_INT_CONTROL, ATLAS_REG_INT_CONTROL),
>  	regmap_reg_range(ATLAS_REG_PH_DATA, ATLAS_REG_PH_DATA + 4),
> +	regmap_reg_range(ATLAS_REG_EC_DATA, ATLAS_REG_PSS_DATA + 4),
>  };
>  
>  static const struct regmap_access_table atlas_volatile_table = {
> @@ -86,7 +102,7 @@ static const struct regmap_config atlas_regmap_config = {
>  	.val_bits = 8,
>  
>  	.volatile_table = &atlas_volatile_table,
> -	.max_register = ATLAS_REG_PH_DATA + 4,
> +	.max_register = ATLAS_REG_PSS_DATA + 4,
>  	.cache_type = REGCACHE_RBTREE,
>  };
>  
> @@ -115,6 +131,38 @@ static const struct iio_chan_spec atlas_ph_channels[] = {
>  	},
>  };
>  
> +#define ATLAS_EC_CHANNEL(idx, addr) \
> +	{\
> +		.type = IIO_CONCENTRATION, \
> +		.indexed = 1, \
> +		.channel = idx, \
> +		.address = addr, \
> +		.info_mask_separate = \
> +			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
> +		.scan_index = idx, \
> +		.scan_type = { \
> +			.sign = 'u', \
> +			.realbits = 32, \
> +			.storagebits = 32, \
> +			.endianness = IIO_BE, \
> +		}, \
> +	}
> +
> +static const struct iio_chan_spec atlas_ec_channels[] = {
> +	ATLAS_EC_CHANNEL(0, ATLAS_REG_EC_DATA),
> +	ATLAS_EC_CHANNEL(1, ATLAS_REG_TDS_DATA),
> +	ATLAS_EC_CHANNEL(2, ATLAS_REG_PSS_DATA),
This needs some explanation.  3 concentration channels of different types?
What are they...
> +	IIO_CHAN_SOFT_TIMESTAMP(3),
> +	{
> +		.type = IIO_TEMP,
> +		.address = ATLAS_REG_EC_TEMP_DATA,
> +		.info_mask_separate =
> +			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> +		.output = 1,
> +		.scan_index = -1
> +	},
> +};
> +
>  static int atlas_check_ph_calibration(struct atlas_data *data)
>  {
>  	struct device *dev = &data->client->dev;
> @@ -142,6 +190,44 @@ static int atlas_check_ph_calibration(struct atlas_data *data)
>  	return 0;
>  }
>  
> +static int atlas_check_ec_calibration(struct atlas_data *data)
> +{
> +	struct device *dev = &data->client->dev;
> +	int ret;
> +	unsigned int val;
> +
> +	ret = regmap_bulk_read(data->regmap, ATLAS_REG_EC_PROBE, &val, 2);
> +	if (ret)
> +		return ret;
> +
> +	dev_info(dev, "probe set to K = %d.%.2d", be16_to_cpu(val) / 100,
> +						 be16_to_cpu(val) % 100);
> +
> +	ret = regmap_read(data->regmap, ATLAS_REG_EC_CALIB_STATUS, &val);
> +	if (ret)
> +		return ret;
> +
> +	if (!(val & ATLAS_REG_EC_CALIB_STATUS_MASK)) {
> +		dev_warn(dev, "device has not been calibrated\n");
> +		return 0;
> +	}
> +
> +	if (!(val & ATLAS_REG_EC_CALIB_STATUS_DRY))
> +		dev_warn(dev, "device missing dry point calibration\n");
> +
> +	if (val & ATLAS_REG_EC_CALIB_STATUS_SINGLE) {
> +		dev_warn(dev, "device using single point calibration\n");
> +	} else {
> +		if (!(val & ATLAS_REG_EC_CALIB_STATUS_LOW))
> +			dev_warn(dev, "device missing low point calibration\n");
> +
> +		if (!(val & ATLAS_REG_EC_CALIB_STATUS_HIGH))
> +			dev_warn(dev, "device missing high point calibration\n");
> +	}
> +
> +	return 0;
> +}
> +
>  struct atlas_device {
>  	const struct iio_chan_spec *channels;
>  	int num_channels;
> @@ -159,6 +245,14 @@ static struct atlas_device atlas_devices[] = {
>  				.calibration = &atlas_check_ph_calibration,
>  				.delay = ATLAS_PH_INT_TIME_IN_US,
>  	},
> +	[ATLAS_EC_SM] = {
> +				.channels = atlas_ec_channels,
> +				.num_channels = 5,
Use array_size - obviously correct that way so I don't have to go count...
> +				.data_reg = ATLAS_REG_EC_DATA,
> +				.calibration = &atlas_check_ec_calibration,
> +				.delay = ATLAS_EC_INT_TIME_IN_US,
> +	},
> +
>  };
>  
>  static int atlas_set_powermode(struct atlas_data *data, int on)
> @@ -294,6 +388,7 @@ static int atlas_read_raw(struct iio_dev *indio_dev,
>  					      (u8 *) &reg, sizeof(reg));
I guess it's not complex enough to justify splitting read_raw for the two
devices.  Close though so you may want to if you support a third type in here.

>  			break;
>  		case IIO_PH:
> +		case IIO_CONCENTRATION:
>  			mutex_lock(&indio_dev->mlock);
>  
>  			if (iio_buffer_enabled(indio_dev))
> @@ -324,6 +419,18 @@ static int atlas_read_raw(struct iio_dev *indio_dev,
>  			*val = 1; /* 0.001 */
>  			*val2 = 1000;
>  			break;
> +		case IIO_CONCENTRATION:
> +			switch (chan->address) {
> +			case ATLAS_REG_EC_DATA:
> +				*val = 0; /* 0.00000000064 */
> +				*val2 = 640;
> +				return IIO_VAL_INT_PLUS_NANO;
> +			default:
> +				*val = 0; /* 0.000000001 */
> +				*val2 = 1000;
> +				return IIO_VAL_INT_PLUS_NANO;
> +			}
> +			break;
>  		default:
>  			return -EINVAL;
>  		}
> @@ -517,12 +624,14 @@ static const struct dev_pm_ops atlas_pm_ops = {
>  
>  static const struct i2c_device_id atlas_id[] = {
>  	{ "atlas-ph-sm", ATLAS_PH_SM},
> +	{ "atlas-ec-sm", ATLAS_EC_SM},
>  	{}
>  };
>  MODULE_DEVICE_TABLE(i2c, atlas_id);
>  
>  static const struct of_device_id atlas_dt_ids[] = {
>  	{ .compatible = "atlas,ph-sm", .data = (void *)ATLAS_PH_SM, },
> +	{ .compatible = "atlas,ec-sm", .data = (void *)ATLAS_EC_SM, },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(of, atlas_dt_ids);
>