| Message ID | 1529161484-28781-4-git-send-email-akinobu.mita@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, 17 Jun 2018 00:04:42 +0900 Akinobu Mita <akinobu.mita@gmail.com> wrote: > The ADXL345 provides the offset adjustment registers for each axis. > This adds the iio channel information for the calibraion offsets with > that feature. > > Cc: Eva Rachel Retuya <eraretuya@gmail.com> > Cc: Andy Shevchenko <andy.shevchenko@gmail.com> > Cc: Jonathan Cameron <jic23@kernel.org> > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Hi, The use of calibscale surprised me. Calibbias is often effectively in 'unknown units' as there is non linear stuff in the way but roughly speaking the assumption is that it is in the same units as the _raw measurement if it can be (hence calibscale = 1). adc reading = ((actualval + calibbias)*calibscale) processed reading = (adc reading + offset)*scale Looks like it would be easy enough to do that here and rely on default for calibscale of 1. That gives us one less userspace interface which is one less thing for people to use wrong :) > --- > drivers/iio/accel/adxl345_core.c | 52 +++++++++++++++++++++++++++++++++++----- > 1 file changed, 46 insertions(+), 6 deletions(-) > > diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c > index 6b62f82..a392f9e 100644 > --- a/drivers/iio/accel/adxl345_core.c > +++ b/drivers/iio/accel/adxl345_core.c > @@ -18,6 +18,9 @@ > #include "adxl345.h" > > #define ADXL345_REG_DEVID 0x00 > +#define ADXL345_REG_OFSX 0x1e > +#define ADXL345_REG_OFSY 0x1f > +#define ADXL345_REG_OFSZ 0x20 > #define ADXL345_REG_POWER_CTL 0x2D > #define ADXL345_REG_DATA_FORMAT 0x31 > #define ADXL345_REG_DATAX0 0x32 > @@ -53,8 +56,10 @@ struct adxl345_data { > .type = IIO_ACCEL, \ > .modified = 1, \ > .channel2 = IIO_MOD_##axis, \ > - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ > + BIT(IIO_CHAN_INFO_CALIBBIAS), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ > + BIT(IIO_CHAN_INFO_CALIBSCALE), \ > .scan_index = si, \ > } > > @@ -69,7 +74,8 @@ static int adxl345_read_raw(struct iio_dev *indio_dev, > int *val, int *val2, long mask) > { > struct adxl345_data *data = iio_priv(indio_dev); > - __le16 regval; > + __le16 accel; > + unsigned int regval; > int ret; > > switch (mask) { > @@ -80,18 +86,51 @@ static int adxl345_read_raw(struct iio_dev *indio_dev, > * and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte > */ > ret = regmap_bulk_read(data->regmap, ADXL345_REG_DATAX0 + > - sizeof(regval) * chan->scan_index, > - ®val, sizeof(regval)); > + sizeof(accel) * chan->scan_index, &accel, > + sizeof(accel)); > if (ret < 0) > return ret; > > - *val = sign_extend32(le16_to_cpu(regval), 12); > + *val = sign_extend32(le16_to_cpu(accel), 12); > return IIO_VAL_INT; > case IIO_CHAN_INFO_SCALE: > *val = 0; > *val2 = adxl345_uscale; > > return IIO_VAL_INT_PLUS_MICRO; > + case IIO_CHAN_INFO_CALIBBIAS: > + ret = regmap_read(data->regmap, > + ADXL345_REG_OFSX + chan->scan_index, ®val); > + if (ret < 0) > + return ret; > + *val = sign_extend32(regval, 7); > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_CALIBSCALE: > + /* > + * 8-bit resolution at +/- 2g, that is 4x accel data scale > + * factor > + */ > + *val = 0; > + *val2 = adxl345_uscale * 4; This surprises me. Why am I seeing a read only calibration scale parameter? The ABI doesn't say that this is the scale of the bias if that's what you are thinking... calibbias is kind of unit less as often it's before a non linear transform of some type. However, if we were going to assume it was simple, we'd assume it had the same scale as _raw. Hence I would just adjust the value in the read and write for the calibbias itself. > + > + return IIO_VAL_INT_PLUS_MICRO; > + } > + > + return -EINVAL; > +} > + > +static int adxl345_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + struct adxl345_data *data = iio_priv(indio_dev); > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_CALIBBIAS: > + ret = regmap_write(data->regmap, > + ADXL345_REG_OFSX + chan->scan_index, val); > + return ret; > } > > return -EINVAL; > @@ -99,6 +138,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev, > > static const struct iio_info adxl345_info = { > .read_raw = adxl345_read_raw, > + .write_raw = adxl345_write_raw, > }; > > int adxl345_core_probe(struct device *dev, struct regmap *regmap, -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2018年6月17日(日) 3:48 Jonathan Cameron <jic23@kernel.org>: > > On Sun, 17 Jun 2018 00:04:42 +0900 > Akinobu Mita <akinobu.mita@gmail.com> wrote: > > > The ADXL345 provides the offset adjustment registers for each axis. > > This adds the iio channel information for the calibraion offsets with > > that feature. > > > > Cc: Eva Rachel Retuya <eraretuya@gmail.com> > > Cc: Andy Shevchenko <andy.shevchenko@gmail.com> > > Cc: Jonathan Cameron <jic23@kernel.org> > > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > Hi, > > The use of calibscale surprised me. Calibbias is often effectively in > 'unknown units' as there is non linear stuff in the way but roughly speaking > the assumption is that it is in the same units as the _raw measurement if it > can be (hence calibscale = 1). > > adc reading = ((actualval + calibbias)*calibscale) > processed reading = (adc reading + offset)*scale > > Looks like it would be easy enough to do that here and rely on default for > calibscale of 1. That gives us one less userspace interface which is one > less thing for people to use wrong :) > > > --- > > drivers/iio/accel/adxl345_core.c | 52 +++++++++++++++++++++++++++++++++++----- > > 1 file changed, 46 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c > > index 6b62f82..a392f9e 100644 > > --- a/drivers/iio/accel/adxl345_core.c > > +++ b/drivers/iio/accel/adxl345_core.c > > @@ -18,6 +18,9 @@ > > #include "adxl345.h" > > > > #define ADXL345_REG_DEVID 0x00 > > +#define ADXL345_REG_OFSX 0x1e > > +#define ADXL345_REG_OFSY 0x1f > > +#define ADXL345_REG_OFSZ 0x20 > > #define ADXL345_REG_POWER_CTL 0x2D > > #define ADXL345_REG_DATA_FORMAT 0x31 > > #define ADXL345_REG_DATAX0 0x32 > > @@ -53,8 +56,10 @@ struct adxl345_data { > > .type = IIO_ACCEL, \ > > .modified = 1, \ > > .channel2 = IIO_MOD_##axis, \ > > - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > > - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ > > + BIT(IIO_CHAN_INFO_CALIBBIAS), \ > > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ > > + BIT(IIO_CHAN_INFO_CALIBSCALE), \ > > .scan_index = si, \ > > } > > > > @@ -69,7 +74,8 @@ static int adxl345_read_raw(struct iio_dev *indio_dev, > > int *val, int *val2, long mask) > > { > > struct adxl345_data *data = iio_priv(indio_dev); > > - __le16 regval; > > + __le16 accel; > > + unsigned int regval; > > int ret; > > > > switch (mask) { > > @@ -80,18 +86,51 @@ static int adxl345_read_raw(struct iio_dev *indio_dev, > > * and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte > > */ > > ret = regmap_bulk_read(data->regmap, ADXL345_REG_DATAX0 + > > - sizeof(regval) * chan->scan_index, > > - ®val, sizeof(regval)); > > + sizeof(accel) * chan->scan_index, &accel, > > + sizeof(accel)); > > if (ret < 0) > > return ret; > > > > - *val = sign_extend32(le16_to_cpu(regval), 12); > > + *val = sign_extend32(le16_to_cpu(accel), 12); > > return IIO_VAL_INT; > > case IIO_CHAN_INFO_SCALE: > > *val = 0; > > *val2 = adxl345_uscale; > > > > return IIO_VAL_INT_PLUS_MICRO; > > + case IIO_CHAN_INFO_CALIBBIAS: > > + ret = regmap_read(data->regmap, > > + ADXL345_REG_OFSX + chan->scan_index, ®val); > > + if (ret < 0) > > + return ret; > > + *val = sign_extend32(regval, 7); > > + return IIO_VAL_INT; > > + case IIO_CHAN_INFO_CALIBSCALE: > > + /* > > + * 8-bit resolution at +/- 2g, that is 4x accel data scale > > + * factor > > + */ > > + *val = 0; > > + *val2 = adxl345_uscale * 4; > > This surprises me. Why am I seeing a read only calibration scale parameter? > The ABI doesn't say that this is the scale of the bias if that's what you are thinking... I completely misunderstood calibscale. > calibbias is kind of unit less as often it's before a non linear transform of some > type. However, if we were going to assume it was simple, we'd assume it had the > same scale as _raw. Hence I would just adjust the value in the read and write for > the calibbias itself. Sounds good. I'll change the code to adjust the value for the calibbias to make the same scale as the _raw measurement, and remove misused calibscale. > > + > > + return IIO_VAL_INT_PLUS_MICRO; > > + } > > + > > + return -EINVAL; > > +} > > + > > +static int adxl345_write_raw(struct iio_dev *indio_dev, > > + struct iio_chan_spec const *chan, > > + int val, int val2, long mask) > > +{ > > + struct adxl345_data *data = iio_priv(indio_dev); > > + int ret; > > + > > + switch (mask) { > > + case IIO_CHAN_INFO_CALIBBIAS: > > + ret = regmap_write(data->regmap, > > + ADXL345_REG_OFSX + chan->scan_index, val); > > + return ret; > > } > > > > return -EINVAL; > > @@ -99,6 +138,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev, > > > > static const struct iio_info adxl345_info = { > > .read_raw = adxl345_read_raw, > > + .write_raw = adxl345_write_raw, > > }; > > > > int adxl345_core_probe(struct device *dev, struct regmap *regmap, > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c index 6b62f82..a392f9e 100644 --- a/drivers/iio/accel/adxl345_core.c +++ b/drivers/iio/accel/adxl345_core.c @@ -18,6 +18,9 @@ #include "adxl345.h" #define ADXL345_REG_DEVID 0x00 +#define ADXL345_REG_OFSX 0x1e +#define ADXL345_REG_OFSY 0x1f +#define ADXL345_REG_OFSZ 0x20 #define ADXL345_REG_POWER_CTL 0x2D #define ADXL345_REG_DATA_FORMAT 0x31 #define ADXL345_REG_DATAX0 0x32 @@ -53,8 +56,10 @@ struct adxl345_data { .type = IIO_ACCEL, \ .modified = 1, \ .channel2 = IIO_MOD_##axis, \ - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_CALIBBIAS), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_CALIBSCALE), \ .scan_index = si, \ } @@ -69,7 +74,8 @@ static int adxl345_read_raw(struct iio_dev *indio_dev, int *val, int *val2, long mask) { struct adxl345_data *data = iio_priv(indio_dev); - __le16 regval; + __le16 accel; + unsigned int regval; int ret; switch (mask) { @@ -80,18 +86,51 @@ static int adxl345_read_raw(struct iio_dev *indio_dev, * and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte */ ret = regmap_bulk_read(data->regmap, ADXL345_REG_DATAX0 + - sizeof(regval) * chan->scan_index, - ®val, sizeof(regval)); + sizeof(accel) * chan->scan_index, &accel, + sizeof(accel)); if (ret < 0) return ret; - *val = sign_extend32(le16_to_cpu(regval), 12); + *val = sign_extend32(le16_to_cpu(accel), 12); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = 0; *val2 = adxl345_uscale; return IIO_VAL_INT_PLUS_MICRO; + case IIO_CHAN_INFO_CALIBBIAS: + ret = regmap_read(data->regmap, + ADXL345_REG_OFSX + chan->scan_index, ®val); + if (ret < 0) + return ret; + *val = sign_extend32(regval, 7); + return IIO_VAL_INT; + case IIO_CHAN_INFO_CALIBSCALE: + /* + * 8-bit resolution at +/- 2g, that is 4x accel data scale + * factor + */ + *val = 0; + *val2 = adxl345_uscale * 4; + + return IIO_VAL_INT_PLUS_MICRO; + } + + return -EINVAL; +} + +static int adxl345_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct adxl345_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_CALIBBIAS: + ret = regmap_write(data->regmap, + ADXL345_REG_OFSX + chan->scan_index, val); + return ret; } return -EINVAL; @@ -99,6 +138,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev, static const struct iio_info adxl345_info = { .read_raw = adxl345_read_raw, + .write_raw = adxl345_write_raw, }; int adxl345_core_probe(struct device *dev, struct regmap *regmap,
The ADXL345 provides the offset adjustment registers for each axis. This adds the iio channel information for the calibraion offsets with that feature. Cc: Eva Rachel Retuya <eraretuya@gmail.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> --- drivers/iio/accel/adxl345_core.c | 52 +++++++++++++++++++++++++++++++++++----- 1 file changed, 46 insertions(+), 6 deletions(-)