Re: [PATCH v2 5/9] Staging: iio: accel: adis16201: Add comments about units in read_raw()

2018-03-18 Thread Jonathan Cameron 
On Sat, 17 Mar 2018 01:36:22 +0530
Himanshu Jha  wrote:

> Clarify the conversion and formation of resultant data in the
> adis16201_read_raw() with sufficient comments and remove the unnecessary
> comments.
> 
> Signed-off-by: Himanshu Jha 
It is a little illogical to have comments for all but one of the channels, but
given we don't normally comment them unless they are 'odd', this is fine.

Applied, thanks

Jonathan

> ---
> v2:
>-clarify voltage base conversions.
> 
>  drivers/staging/iio/accel/adis16201.c | 27 ++-
>  1 file changed, 18 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/staging/iio/accel/adis16201.c 
> b/drivers/staging/iio/accel/adis16201.c
> index 8de3f27..97150ea 100644
> --- a/drivers/staging/iio/accel/adis16201.c
> +++ b/drivers/staging/iio/accel/adis16201.c
> @@ -120,31 +120,43 @@ static int adis16201_read_raw(struct iio_dev *indio_dev,
>   switch (chan->type) {
>   case IIO_VOLTAGE:
>   if (chan->channel == 0) {
> + /* Voltage base units are mV hence 1.22 mV */
>   *val = 1;
> - *val2 = 22; /* 1.22 mV */
> + *val2 = 22;
>   } else {
> + /* Voltage base units are mV hence 0.61 mV */
>   *val = 0;
> - *val2 = 61; /* 0.610 mV */
> + *val2 = 61;
>   }
>   return IIO_VAL_INT_PLUS_MICRO;
>   case IIO_TEMP:
> - *val = -470; /* 0.47 C */
> + *val = -470;
>   *val2 = 0;
>   return IIO_VAL_INT_PLUS_MICRO;
>   case IIO_ACCEL:
> + /*
> +  * IIO base unit for sensitivity of accelerometer
> +  * is milli g.
> +  * 1 LSB represents 0.244 mg.
> +  */
>   *val = 0;
> - *val2 = IIO_G_TO_M_S_2(462400); /* 0.4624 mg */
> + *val2 = IIO_G_TO_M_S_2(462400);
>   return IIO_VAL_INT_PLUS_NANO;
>   case IIO_INCLI:
>   *val = 0;
> - *val2 = 10; /* 0.1 degree */
> + *val2 = 10;
>   return IIO_VAL_INT_PLUS_MICRO;
>   default:
>   return -EINVAL;
>   }
>   break;
>   case IIO_CHAN_INFO_OFFSET:
> - *val = 25000 / -470 - 1278; /* 25 C = 1278 */
> + /*
> +  * The raw ADC value is 1278 when the temperature
> +  * is 25 degrees and the scale factor per milli
> +  * degree celcius is -470.
> +  */
> + *val = 25000 / -470 - 1278;
>   return IIO_VAL_INT;
>   case IIO_CHAN_INFO_CALIBBIAS:
>   switch (chan->type) {
> @@ -252,13 +264,11 @@ static int adis16201_probe(struct spi_device *spi)
>   struct adis *st;
>   struct iio_dev *indio_dev;
>  
> - /* setup the industrialio driver allocated elements */
>   indio_dev = devm_iio_device_alloc(>dev, sizeof(*st));
>   if (!indio_dev)
>   return -ENOMEM;
>  
>   st = iio_priv(indio_dev);
> - /* this is only used for removal purposes */
>   spi_set_drvdata(spi, indio_dev);
>  
>   indio_dev->name = spi->dev.driver->name;
> @@ -277,7 +287,6 @@ static int adis16201_probe(struct spi_device *spi)
>   if (ret)
>   return ret;
>  
> - /* Get the device into a sane initial state */
>   ret = adis_initial_startup(st);
>   if (ret)
>   goto error_cleanup_buffer_trigger;

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[PATCH v2 5/9] Staging: iio: accel: adis16201: Add comments about units in read_raw()

2018-03-16 Thread Himanshu Jha 
Clarify the conversion and formation of resultant data in the
adis16201_read_raw() with sufficient comments and remove the unnecessary
comments.

Signed-off-by: Himanshu Jha 
---
v2:
   -clarify voltage base conversions.

 drivers/staging/iio/accel/adis16201.c | 27 ++-
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/iio/accel/adis16201.c 
b/drivers/staging/iio/accel/adis16201.c
index 8de3f27..97150ea 100644
--- a/drivers/staging/iio/accel/adis16201.c
+++ b/drivers/staging/iio/accel/adis16201.c
@@ -120,31 +120,43 @@ static int adis16201_read_raw(struct iio_dev *indio_dev,
switch (chan->type) {
case IIO_VOLTAGE:
if (chan->channel == 0) {
+   /* Voltage base units are mV hence 1.22 mV */
*val = 1;
-   *val2 = 22; /* 1.22 mV */
+   *val2 = 22;
} else {
+   /* Voltage base units are mV hence 0.61 mV */
*val = 0;
-   *val2 = 61; /* 0.610 mV */
+   *val2 = 61;
}
return IIO_VAL_INT_PLUS_MICRO;
case IIO_TEMP:
-   *val = -470; /* 0.47 C */
+   *val = -470;
*val2 = 0;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_ACCEL:
+   /*
+* IIO base unit for sensitivity of accelerometer
+* is milli g.
+* 1 LSB represents 0.244 mg.
+*/
*val = 0;
-   *val2 = IIO_G_TO_M_S_2(462400); /* 0.4624 mg */
+   *val2 = IIO_G_TO_M_S_2(462400);
return IIO_VAL_INT_PLUS_NANO;
case IIO_INCLI:
*val = 0;
-   *val2 = 10; /* 0.1 degree */
+   *val2 = 10;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
break;
case IIO_CHAN_INFO_OFFSET:
-   *val = 25000 / -470 - 1278; /* 25 C = 1278 */
+   /*
+* The raw ADC value is 1278 when the temperature
+* is 25 degrees and the scale factor per milli
+* degree celcius is -470.
+*/
+   *val = 25000 / -470 - 1278;
return IIO_VAL_INT;
case IIO_CHAN_INFO_CALIBBIAS:
switch (chan->type) {
@@ -252,13 +264,11 @@ static int adis16201_probe(struct spi_device *spi)
struct adis *st;
struct iio_dev *indio_dev;
 
-   /* setup the industrialio driver allocated elements */
indio_dev = devm_iio_device_alloc(>dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
 
st = iio_priv(indio_dev);
-   /* this is only used for removal purposes */
spi_set_drvdata(spi, indio_dev);
 
indio_dev->name = spi->dev.driver->name;
@@ -277,7 +287,6 @@ static int adis16201_probe(struct spi_device *spi)
if (ret)
return ret;
 
-   /* Get the device into a sane initial state */
ret = adis_initial_startup(st);
if (ret)
goto error_cleanup_buffer_trigger;
-- 
2.7.4

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