diff mbox series

[v1,09/13] iio: chemical: bme680: Move ambient temperature to attributes

Message ID 20241010210030.33309-10-vassilisamir@gmail.com (mailing list archive)
State Changes Requested
Headers show
Series : chemical: bme680: 2nd set of clean and add | expand

Commit Message

Vasileios Amoiridis Oct. 10, 2024, 9 p.m. UTC
From: Vasileios Amoiridis <vassilisamir@gmail.com>

Remove the ambient temperature from being a macro and implement it as
an attribute. This way, it is possible to dynamically configure the
ambient temperature of the environment to improve the accuracy of the
measurements.

Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
 drivers/iio/chemical/bme680.h      |  1 -
 drivers/iio/chemical/bme680_core.c | 35 +++++++++++++++++++++++++++++-
 2 files changed, 34 insertions(+), 2 deletions(-)

Comments

Andy Shevchenko Oct. 11, 2024, 10:12 a.m. UTC | #1
On Thu, Oct 10, 2024 at 11:00:26PM +0200, vamoirid wrote:
> From: Vasileios Amoiridis <vassilisamir@gmail.com>
> 
> Remove the ambient temperature from being a macro and implement it as
> an attribute. This way, it is possible to dynamically configure the
> ambient temperature of the environment to improve the accuracy of the
> measurements.

...

> -	var1 = (((s32)BME680_AMB_TEMP * calib->par_gh3) / 1000) * 256;
> +	var1 = (((s32)data->ambient_temp * calib->par_gh3) / 1000) * 256;

MILLI? KILO?

...

>  static struct attribute *bme680_attributes[] = {
>  	&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
> +	&iio_dev_attr_ambient_temp.dev_attr.attr,
>  	NULL,

Side note: Perhaps a patch or an additional change in the existing one to drop
the trailing comma here.

>  };
Vasileios Amoiridis Oct. 11, 2024, 7:03 p.m. UTC | #2
On Fri, Oct 11, 2024 at 01:12:21PM +0300, Andy Shevchenko wrote:
> On Thu, Oct 10, 2024 at 11:00:26PM +0200, vamoirid wrote:
> > From: Vasileios Amoiridis <vassilisamir@gmail.com>
> > 
> > Remove the ambient temperature from being a macro and implement it as
> > an attribute. This way, it is possible to dynamically configure the
> > ambient temperature of the environment to improve the accuracy of the
> > measurements.
> 
> ...
> 
> > -	var1 = (((s32)BME680_AMB_TEMP * calib->par_gh3) / 1000) * 256;
> > +	var1 = (((s32)data->ambient_temp * calib->par_gh3) / 1000) * 256;
> 
> MILLI? KILO?
>

I could do it yes.

> ...
> 
> >  static struct attribute *bme680_attributes[] = {
> >  	&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
> > +	&iio_dev_attr_ambient_temp.dev_attr.attr,
> >  	NULL,
> 
> Side note: Perhaps a patch or an additional change in the existing one to drop
> the trailing comma here.
> 

I could add an additional change if you think it is worth the churn.

> >  };
> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 

Cheers,
Vasilis
Jonathan Cameron Oct. 12, 2024, 12:01 p.m. UTC | #3
On Thu, 10 Oct 2024 23:00:26 +0200
vamoirid <vassilisamir@gmail.com> wrote:

> From: Vasileios Amoiridis <vassilisamir@gmail.com>
> 
> Remove the ambient temperature from being a macro and implement it as
> an attribute. This way, it is possible to dynamically configure the
> ambient temperature of the environment to improve the accuracy of the
> measurements.
> 
> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
New ABI? Would need docs.

However, I 'think' we have a few cases where we handle this via the slightly
odd interface of out_temp_processed / _raw with a label saying it's
ambient temperature.

The tenuous argument is that we have heaters that actually control the
temperature and the affect of either heating the thing or just happening
to know the external temperature ends up being the same. Hence use
an output channel for this control.

Jonathan
Vasileios Amoiridis Oct. 14, 2024, 8:14 p.m. UTC | #4
On Sat, Oct 12, 2024 at 01:01:24PM +0100, Jonathan Cameron wrote:
> On Thu, 10 Oct 2024 23:00:26 +0200
> vamoirid <vassilisamir@gmail.com> wrote:
> 
> > From: Vasileios Amoiridis <vassilisamir@gmail.com>
> > 
> > Remove the ambient temperature from being a macro and implement it as
> > an attribute. This way, it is possible to dynamically configure the
> > ambient temperature of the environment to improve the accuracy of the
> > measurements.
> > 
> > Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
> New ABI? Would need docs.
> 
> However, I 'think' we have a few cases where we handle this via the slightly
> odd interface of out_temp_processed / _raw with a label saying it's
> ambient temperature.
> 
> The tenuous argument is that we have heaters that actually control the
> temperature and the affect of either heating the thing or just happening
> to know the external temperature ends up being the same. Hence use
> an output channel for this control.
> 
> Jonathan

Hi Jonathan,

Thanks for taking the time to review this. I saw your previous messages,
and I am not responding to all of them so as to not flood you with ACK
messages.

For this one though I have to ask. The last commit of this series is
adding support for an output current channel that controls the current
that is being inserted into an internal plate that is heated up in order
to have more precise acquisition of humidity and gas measurement. Does
it makes sense to add an ambient temp output channel as well?

Cheers,
Vasilis
diff mbox series

Patch

diff --git a/drivers/iio/chemical/bme680.h b/drivers/iio/chemical/bme680.h
index e9e3e08fa366..95d39c154d59 100644
--- a/drivers/iio/chemical/bme680.h
+++ b/drivers/iio/chemical/bme680.h
@@ -45,7 +45,6 @@ 
 #define BME680_REG_RES_HEAT_0			0x5A
 #define BME680_REG_GAS_WAIT_0			0x64
 #define BME680_ADC_GAS_RES			GENMASK(15, 6)
-#define BME680_AMB_TEMP				25
 
 #define BME680_REG_CTRL_GAS_1			0x71
 #define   BME680_RUN_GAS_MASK			BIT(4)
diff --git a/drivers/iio/chemical/bme680_core.c b/drivers/iio/chemical/bme680_core.c
index 5fd5740bb7fe..0979c8f0afcf 100644
--- a/drivers/iio/chemical/bme680_core.c
+++ b/drivers/iio/chemical/bme680_core.c
@@ -120,6 +120,7 @@  struct bme680_data {
 	u16 heater_temp;
 
 	struct regulator_bulk_data supplies[BME680_NUM_SUPPLIES];
+	int ambient_temp;
 
 	union {
 		u8 buf[3];
@@ -483,7 +484,7 @@  static u8 bme680_calc_heater_res(struct bme680_data *data, u16 temp)
 	if (temp > 400) /* Cap temperature */
 		temp = 400;
 
-	var1 = (((s32)BME680_AMB_TEMP * calib->par_gh3) / 1000) * 256;
+	var1 = (((s32)data->ambient_temp * calib->par_gh3) / 1000) * 256;
 	var2 = (calib->par_gh1 + 784) * (((((calib->par_gh2 + 154009) *
 						temp * 5) / 100)
 						+ 3276800) / 10);
@@ -878,6 +879,37 @@  static int bme680_write_raw(struct iio_dev *indio_dev,
 	return ret;
 }
 
+static ssize_t ambient_temp_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bme680_data *data = iio_priv(indio_dev);
+	int vals[2];
+
+	vals[0] = data->ambient_temp;
+	vals[1] = 1;
+
+	return iio_format_value(buf, IIO_VAL_INT, 1, vals);
+}
+
+static ssize_t ambient_temp_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bme680_data *data = iio_priv(indio_dev);
+	int ret, val_int, val_fract;
+
+	ret = iio_str_to_fixpoint(buf, 1, &val_int, &val_fract);
+	if (ret)
+		return ret;
+
+	data->ambient_temp = val_int;
+	return len;
+}
+
+static IIO_DEVICE_ATTR_RW(ambient_temp, 0);
+
 static const char bme680_oversampling_ratio_show[] = "1 2 4 8 16";
 
 static IIO_CONST_ATTR(oversampling_ratio_available,
@@ -885,6 +917,7 @@  static IIO_CONST_ATTR(oversampling_ratio_available,
 
 static struct attribute *bme680_attributes[] = {
 	&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
+	&iio_dev_attr_ambient_temp.dev_attr.attr,
 	NULL,
 };