| Message ID | 20220509134629.440965-2-Qing-wu.Li@leica-geosystems.com.cn (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | iio: accel: bmi088: support BMI085 BMI090L | expand |
On Mon, May 9, 2022 at 4:46 PM LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn> wrote: > > The units after application of scale are 100*m/s^2, > The scale calculation is only for the device > with the range of 3, 6, 12, and 24g, > but some other chips have a range of 2, 4, 6, and 8g. > > Modified the formula to a scale list. > The scales in the list are calculated by 1/sensitivity*9.8. > The new units after the application of scale are m/s^2. > > Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn> > --- > drivers/iio/accel/bmi088-accel-core.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/drivers/iio/accel/bmi088-accel-core.c b/drivers/iio/accel/bmi088-accel-core.c > index a06dae5c971d..0c58ffdd00e3 100644 > --- a/drivers/iio/accel/bmi088-accel-core.c > +++ b/drivers/iio/accel/bmi088-accel-core.c > @@ -119,6 +119,7 @@ struct bmi088_accel_chip_info { > u8 chip_id; > const struct iio_chan_spec *channels; > int num_channels; > + const int scale_table[4][2]; > }; > > struct bmi088_accel_data { > @@ -280,6 +281,7 @@ static int bmi088_accel_read_raw(struct iio_dev *indio_dev, > struct bmi088_accel_data *data = iio_priv(indio_dev); > struct device *dev = regmap_get_device(data->regmap); > int ret; > + int reg; > > switch (mask) { > case IIO_CHAN_INFO_RAW: > @@ -330,13 +332,12 @@ static int bmi088_accel_read_raw(struct iio_dev *indio_dev, > return ret; > > ret = regmap_read(data->regmap, > - BMI088_ACCEL_REG_ACC_RANGE, val); > + BMI088_ACCEL_REG_ACC_RANGE, ®); Curios: do we need to validate the value of `reg` here? If it goes outside of the 0...3 range, I can see a bit of access violation (kernel panic) happening. > if (ret) > goto out_read_raw_pm_put; > - > - *val2 = 15 - (*val & 0x3); > - *val = 3 * 980; > - ret = IIO_VAL_FRACTIONAL_LOG2; Not sure what the policy is about changing this now. I'll leave this to Jonathan. > + *val = data->chip_info->scale_table[reg][0]; > + *val2 = data->chip_info->scale_table[reg][1]; > + ret = IIO_VAL_INT_PLUS_MICRO; > > goto out_read_raw_pm_put; > default: > @@ -432,6 +433,7 @@ static const struct bmi088_accel_chip_info bmi088_accel_chip_info_tbl[] = { > .chip_id = 0x1E, > .channels = bmi088_accel_channels, > .num_channels = ARRAY_SIZE(bmi088_accel_channels), > + .scale_table = {{0, 897}, {0, 1795}, {0, 3590}, {0, 7179}}, I like the idea of this scale_table. It makes things easier to see (what's happening) without looking into the datasheet much. > }, > }; > > -- > 2.25.1 >
On Tue, 10 May 2022 09:01:20 +0300 Alexandru Ardelean <ardeleanalex@gmail.com> wrote: > On Mon, May 9, 2022 at 4:46 PM LI Qingwu > <Qing-wu.Li@leica-geosystems.com.cn> wrote: > > > > The units after application of scale are 100*m/s^2, > > The scale calculation is only for the device > > with the range of 3, 6, 12, and 24g, > > but some other chips have a range of 2, 4, 6, and 8g. > > > > Modified the formula to a scale list. > > The scales in the list are calculated by 1/sensitivity*9.8. > > The new units after the application of scale are m/s^2. > > > > Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn> > > --- > > drivers/iio/accel/bmi088-accel-core.c | 12 +++++++----- > > 1 file changed, 7 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/iio/accel/bmi088-accel-core.c b/drivers/iio/accel/bmi088-accel-core.c > > index a06dae5c971d..0c58ffdd00e3 100644 > > --- a/drivers/iio/accel/bmi088-accel-core.c > > +++ b/drivers/iio/accel/bmi088-accel-core.c > > @@ -119,6 +119,7 @@ struct bmi088_accel_chip_info { > > u8 chip_id; > > const struct iio_chan_spec *channels; > > int num_channels; > > + const int scale_table[4][2]; > > }; > > > > struct bmi088_accel_data { > > @@ -280,6 +281,7 @@ static int bmi088_accel_read_raw(struct iio_dev *indio_dev, > > struct bmi088_accel_data *data = iio_priv(indio_dev); > > struct device *dev = regmap_get_device(data->regmap); > > int ret; > > + int reg; > > > > switch (mask) { > > case IIO_CHAN_INFO_RAW: > > @@ -330,13 +332,12 @@ static int bmi088_accel_read_raw(struct iio_dev *indio_dev, > > return ret; > > > > ret = regmap_read(data->regmap, > > - BMI088_ACCEL_REG_ACC_RANGE, val); > > + BMI088_ACCEL_REG_ACC_RANGE, ®); > > Curios: do we need to validate the value of `reg` here? > If it goes outside of the 0...3 range, I can see a bit of access > violation (kernel panic) happening. > > > if (ret) > > goto out_read_raw_pm_put; > > - > > - *val2 = 15 - (*val & 0x3); > > - *val = 3 * 980; > > - ret = IIO_VAL_FRACTIONAL_LOG2; > > Not sure what the policy is about changing this now. > I'll leave this to Jonathan. It shouldn't be a problem as userspace ABI is a decimal string either way. Only impact might be on precision and those tend to be minor. > > > + *val = data->chip_info->scale_table[reg][0]; > > + *val2 = data->chip_info->scale_table[reg][1]; > > + ret = IIO_VAL_INT_PLUS_MICRO; > > > > goto out_read_raw_pm_put; > > default: > > @@ -432,6 +433,7 @@ static const struct bmi088_accel_chip_info bmi088_accel_chip_info_tbl[] = { > > .chip_id = 0x1E, > > .channels = bmi088_accel_channels, > > .num_channels = ARRAY_SIZE(bmi088_accel_channels), > > + .scale_table = {{0, 897}, {0, 1795}, {0, 3590}, {0, 7179}}, > > I like the idea of this scale_table. > It makes things easier to see (what's happening) without looking into > the datasheet much. > > > }, > > }; > > > > -- > > 2.25.1 > >
diff --git a/drivers/iio/accel/bmi088-accel-core.c b/drivers/iio/accel/bmi088-accel-core.c index a06dae5c971d..0c58ffdd00e3 100644 --- a/drivers/iio/accel/bmi088-accel-core.c +++ b/drivers/iio/accel/bmi088-accel-core.c @@ -119,6 +119,7 @@ struct bmi088_accel_chip_info { u8 chip_id; const struct iio_chan_spec *channels; int num_channels; + const int scale_table[4][2]; }; struct bmi088_accel_data { @@ -280,6 +281,7 @@ static int bmi088_accel_read_raw(struct iio_dev *indio_dev, struct bmi088_accel_data *data = iio_priv(indio_dev); struct device *dev = regmap_get_device(data->regmap); int ret; + int reg; switch (mask) { case IIO_CHAN_INFO_RAW: @@ -330,13 +332,12 @@ static int bmi088_accel_read_raw(struct iio_dev *indio_dev, return ret; ret = regmap_read(data->regmap, - BMI088_ACCEL_REG_ACC_RANGE, val); + BMI088_ACCEL_REG_ACC_RANGE, ®); if (ret) goto out_read_raw_pm_put; - - *val2 = 15 - (*val & 0x3); - *val = 3 * 980; - ret = IIO_VAL_FRACTIONAL_LOG2; + *val = data->chip_info->scale_table[reg][0]; + *val2 = data->chip_info->scale_table[reg][1]; + ret = IIO_VAL_INT_PLUS_MICRO; goto out_read_raw_pm_put; default: @@ -432,6 +433,7 @@ static const struct bmi088_accel_chip_info bmi088_accel_chip_info_tbl[] = { .chip_id = 0x1E, .channels = bmi088_accel_channels, .num_channels = ARRAY_SIZE(bmi088_accel_channels), + .scale_table = {{0, 897}, {0, 1795}, {0, 3590}, {0, 7179}}, }, };
The units after application of scale are 100*m/s^2, The scale calculation is only for the device with the range of 3, 6, 12, and 24g, but some other chips have a range of 2, 4, 6, and 8g. Modified the formula to a scale list. The scales in the list are calculated by 1/sensitivity*9.8. The new units after the application of scale are m/s^2. Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn> --- drivers/iio/accel/bmi088-accel-core.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)