Re: [PATCH 3/3] iio: chemical: atlas-ezo-sensor: add support for O2 sensor

[Jonathan Cameron <jic23@kernel.org>]

On Tue,  9 Jun 2020 12:41:17 -0700
Matt Ranostay <matt.ranostay@konsulko.com> wrote:

> Add support for the Atlas EZO O2 chemical sensor which required
> some refactoring of the driver and parsing of i2c transfer.
> 
> Sensor data is converted by the scaling value from percent to
> IIO_CONCENTRATION.
> 
> Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Hohum.  I could just apply this series today (looks good) but
given you just fixed that missing strings problem, that will make
for a messy merge for Greg when I send this via togreg and the
fix via fixes-togreg.

As such I'm going to sit on this one until that fix ends up in my
upstream then pick this up.

Do remind me if I seem to have lost it though once that's true!

Thanks,

Jonathan

> ---
>  drivers/iio/chemical/atlas-ezo-sensor.c | 74 ++++++++++++++++++-------
>  1 file changed, 55 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/iio/chemical/atlas-ezo-sensor.c b/drivers/iio/chemical/atlas-ezo-sensor.c
> index a94eb8a6bf32..94188c84e65f 100644
> --- a/drivers/iio/chemical/atlas-ezo-sensor.c
> +++ b/drivers/iio/chemical/atlas-ezo-sensor.c
> @@ -16,10 +16,11 @@
>  #include <linux/iio/iio.h>
>  
>  #define ATLAS_EZO_DRV_NAME		"atlas-ezo-sensor"
> -#define ATLAS_CO2_INT_TIME_IN_MS	950
> +#define ATLAS_INT_TIME_IN_MS		950
>  
>  enum {
>  	ATLAS_CO2_EZO,
> +	ATLAS_O2_EZO,
>  };
>  
>  struct atlas_ezo_device {
> @@ -38,31 +39,54 @@ struct atlas_ezo_data {
>  	u8 buffer[8];
>  };
>  
> +#define ATLAS_CONCENTRATION_CHANNEL(_modifier) \
> +	{ \
> +		.type = IIO_CONCENTRATION, \
> +		.modified = 1,\
> +		.channel2 = _modifier, \
> +		.info_mask_separate = \
> +			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
> +		.scan_index = 0, \
> +		.scan_type =  { \
> +			.sign = 'u', \
> +			.realbits = 32, \
> +			.storagebits = 32, \
> +			.endianness = IIO_CPU, \
> +		}, \
> +	}
> +
>  static const struct iio_chan_spec atlas_co2_ezo_channels[] = {
> -	{
> -		.type = IIO_CONCENTRATION,
> -		.modified = 1,
> -		.channel2 = IIO_MOD_CO2,
> -		.info_mask_separate =
> -			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> -		.scan_index = 0,
> -		.scan_type = {
> -			.sign = 'u',
> -			.realbits = 32,
> -			.storagebits = 32,
> -			.endianness = IIO_CPU,
> -		},
> -	},
> +	ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_CO2),
> +};
> +
> +static const struct iio_chan_spec atlas_o2_ezo_channels[] = {
> +	ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_O2),
>  };
>  
>  static struct atlas_ezo_device atlas_ezo_devices[] = {
>  	[ATLAS_CO2_EZO] = {
>  		.channels = atlas_co2_ezo_channels,
>  		.num_channels = 1,
> -		.delay = ATLAS_CO2_INT_TIME_IN_MS,
> +		.delay = ATLAS_INT_TIME_IN_MS,
>  	},
> +	[ATLAS_O2_EZO] = {
> +		.channels = atlas_o2_ezo_channels,
> +		.num_channels = 1,
> +		.delay = ATLAS_INT_TIME_IN_MS,
> +	}
>  };
>  
> +static void atlas_ezo_sanitize(char *buf)
> +{
> +	char *ptr = strchr(buf, '.');
> +
> +	if (!ptr)
> +		return;
> +
> +	for (; *ptr; ptr++)
> +		*ptr = *(ptr + 1);
> +}
> +
>  static int atlas_ezo_read_raw(struct iio_dev *indio_dev,
>  			  struct iio_chan_spec const *chan,
>  			  int *val, int *val2, long mask)
> @@ -96,6 +120,9 @@ static int atlas_ezo_read_raw(struct iio_dev *indio_dev,
>  			return -EBUSY;
>  		}
>  
> +		/* removing floating point for fixed number representation */
> +		atlas_ezo_sanitize(data->buffer + 2);
> +
>  		ret = kstrtol(data->buffer + 1, 10, &tmp);
>  
>  		*val = tmp;
> @@ -105,9 +132,16 @@ static int atlas_ezo_read_raw(struct iio_dev *indio_dev,
>  		return ret ? ret : IIO_VAL_INT;
>  	}
>  	case IIO_CHAN_INFO_SCALE:
> -		*val = 0;
> -		*val2 = 100; /* 0.0001 */
> -		return IIO_VAL_INT_PLUS_MICRO;
> +		switch (chan->channel2) {
> +		case IIO_MOD_CO2:
> +			*val = 0;
> +			*val2 = 100; /* 0.0001 */
> +			return IIO_VAL_INT_PLUS_MICRO;
> +		case IIO_MOD_O2:
> +			*val = 100;
> +			return IIO_VAL_INT;
> +		}
> +		return -EINVAL;
>  	}
>  
>  	return 0;
> @@ -119,12 +153,14 @@ static const struct iio_info atlas_info = {
>  
>  static const struct i2c_device_id atlas_ezo_id[] = {
>  	{ "atlas-co2-ezo", ATLAS_CO2_EZO },
> +	{ "atlas-o2-ezo", ATLAS_O2_EZO },
>  	{}
>  };
>  MODULE_DEVICE_TABLE(i2c, atlas_ezo_id);
>  
>  static const struct of_device_id atlas_ezo_dt_ids[] = {
>  	{ .compatible = "atlas,co2-ezo", .data = (void *)ATLAS_CO2_EZO, },
> +	{ .compatible = "atlas,o2-ezo", .data = (void *)ATLAS_O2_EZO, },
>  	{}
>  };
>  MODULE_DEVICE_TABLE(of, atlas_ezo_dt_ids);