Re: [PATCH v1 13/13] iio: chemical: bme680: Add support for preheat current

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 10 Oct 2024 23:00:30 +0200
vamoirid <vassilisamir@gmail.com> wrote:

> From: Vasileios Amoiridis <vassilisamir@gmail.com>
> 
> Add functionality to inject a specified amount of current to the heating
> plate before the start of the gas measurement to allow the sensor to reach
> faster to the requested temperature.
> 
> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
> ---
>  drivers/iio/chemical/bme680.h      |  1 +
>  drivers/iio/chemical/bme680_core.c | 38 ++++++++++++++++++++++++++++++
>  2 files changed, 39 insertions(+)
> 
> diff --git a/drivers/iio/chemical/bme680.h b/drivers/iio/chemical/bme680.h
> index e7eed2962baa..c658cb631b52 100644
> --- a/drivers/iio/chemical/bme680.h
> +++ b/drivers/iio/chemical/bme680.h
> @@ -42,6 +42,7 @@
>  #define   BME680_RHRANGE_MASK			GENMASK(5, 4)
>  #define BME680_REG_RES_HEAT_VAL			0x00
>  #define   BME680_RSERROR_MASK			GENMASK(7, 4)
> +#define BME680_REG_IDAC_HEAT_0			0x50
>  #define BME680_REG_RES_HEAT_0			0x5A
>  #define BME680_REG_GAS_WAIT_0			0x64
>  #define BME680_ADC_GAS_RES			GENMASK(15, 6)
> diff --git a/drivers/iio/chemical/bme680_core.c b/drivers/iio/chemical/bme680_core.c
> index df6ae4355902..6cdf8b9dbf2b 100644
> --- a/drivers/iio/chemical/bme680_core.c
> +++ b/drivers/iio/chemical/bme680_core.c
> @@ -126,6 +126,7 @@ struct bme680_data {
>  	u8 oversampling_temp;
>  	u8 oversampling_press;
>  	u8 oversampling_humid;
> +	u8 preheat_curr;
>  	u16 heater_dur;
>  	u16 heater_temp;
>  
> @@ -223,6 +224,12 @@ static const struct iio_chan_spec bme680_channels[] = {
>  		},
>  	},
>  	IIO_CHAN_SOFT_TIMESTAMP(4),
> +	{
> +		.type = IIO_CURRENT,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +		.output = 1,
> +		.scan_index = 5,

Set scan index to -1
you don't want to create the buffer related attrs for this one

> +	},