On Sun, 2016-10-30 at 16:22 +0000, Jonathan Cameron wrote:
> On 25/10/16 02:30, Song Hongyan wrote:
> >
> > While testing, it was observed that on some platforms the scale
> > value
> > from iio sysfs for gyroscope is always 0 (E.g. Yoga 260). This
> > results
> > in the final angular velocity component values to be zeros.
> >
> > This is caused by insufficient precision of scale value displayed
> > in sysfs.
> > If the precision is changed to nano from current micro, then this
> > is
> > sufficient to display the scale value on this platform.
> > Since this can be a problem for all other HID sensors, increase
> > scale
> > precision of all HID sensors to nano from current micro.
> >
> > Results on Yoga 260:
> >
> > name scale before scale now
> > --------------------------------------------
> > gyro_3d 0.000000 0.000000174
> > als 0.001000 0.001000000
> > magn_3d 0.000001 0.000001000
> > accel_3d 0.000009 0.000009806
> >
> > Signed-off-by: Song Hongyan <hongyan.song@xxxxxxxxx>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Hi Jonathan,
> Hi
>
> Looks right to me, Srinivas, I'd like your Ack on this ideally.
I have added my ACK.
Thanks,
Srinivas
> thanks,
>
> Jonathan
> >
> > ---
> > .../iio/common/hid-sensors/hid-sensor-attributes.c | 56
> > +++++++++++-----------
> > 1 file changed, 28 insertions(+), 28 deletions(-)
> >
> > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > index dc33c1d..b5beea53 100644
> > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > @@ -30,26 +30,26 @@
> > u32 usage_id;
> > int unit; /* 0 for default others from HID sensor spec */
> > int scale_val0; /* scale, whole number */
> > - int scale_val1; /* scale, fraction in micros */
> > + int scale_val1; /* scale, fraction in nanos */
> > } unit_conversion[] = {
> > - {HID_USAGE_SENSOR_ACCEL_3D, 0, 9, 806650},
> > + {HID_USAGE_SENSOR_ACCEL_3D, 0, 9, 806650000},
> > {HID_USAGE_SENSOR_ACCEL_3D,
> > HID_USAGE_SENSOR_UNITS_METERS_PER_SEC_SQRD, 1, 0},
> > {HID_USAGE_SENSOR_ACCEL_3D,
> > - HID_USAGE_SENSOR_UNITS_G, 9, 806650},
> > + HID_USAGE_SENSOR_UNITS_G, 9, 806650000},
> >
> > - {HID_USAGE_SENSOR_GYRO_3D, 0, 0, 17453},
> > + {HID_USAGE_SENSOR_GYRO_3D, 0, 0, 17453293},
> > {HID_USAGE_SENSOR_GYRO_3D,
> > HID_USAGE_SENSOR_UNITS_RADIANS_PER_SECOND, 1, 0},
> > {HID_USAGE_SENSOR_GYRO_3D,
> > - HID_USAGE_SENSOR_UNITS_DEGREES_PER_SECOND, 0,
> > 17453},
> > + HID_USAGE_SENSOR_UNITS_DEGREES_PER_SECOND, 0,
> > 17453293},
> >
> > - {HID_USAGE_SENSOR_COMPASS_3D, 0, 0, 1000},
> > + {HID_USAGE_SENSOR_COMPASS_3D, 0, 0, 1000000},
> > {HID_USAGE_SENSOR_COMPASS_3D,
> > HID_USAGE_SENSOR_UNITS_GAUSS, 1, 0},
> >
> > - {HID_USAGE_SENSOR_INCLINOMETER_3D, 0, 0, 17453},
> > + {HID_USAGE_SENSOR_INCLINOMETER_3D, 0, 0, 17453293},
> > {HID_USAGE_SENSOR_INCLINOMETER_3D,
> > - HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453},
> > + HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453293},
> > {HID_USAGE_SENSOR_INCLINOMETER_3D,
> > HID_USAGE_SENSOR_UNITS_RADIANS, 1, 0},
> >
> > @@ -57,7 +57,7 @@
> > {HID_USAGE_SENSOR_ALS, HID_USAGE_SENSOR_UNITS_LUX, 1, 0},
> >
> > {HID_USAGE_SENSOR_PRESSURE, 0, 100, 0},
> > - {HID_USAGE_SENSOR_PRESSURE, HID_USAGE_SENSOR_UNITS_PASCAL,
> > 0, 1000},
> > + {HID_USAGE_SENSOR_PRESSURE, HID_USAGE_SENSOR_UNITS_PASCAL,
> > 0, 1000000},
> > };
> >
> > static int pow_10(unsigned power)
> > @@ -266,15 +266,15 @@ int hid_sensor_write_raw_hyst_value(struct
> > hid_sensor_common *st,
> > /*
> > * This fuction applies the unit exponent to the scale.
> > * For example:
> > - * 9.806650 ->exp:2-> val0[980]val1[665000]
> > - * 9.000806 ->exp:2-> val0[900]val1[80600]
> > - * 0.174535 ->exp:2-> val0[17]val1[453500]
> > - * 1.001745 ->exp:0-> val0[1]val1[1745]
> > - * 1.001745 ->exp:2-> val0[100]val1[174500]
> > - * 1.001745 ->exp:4-> val0[10017]val1[450000]
> > - * 9.806650 ->exp:-2-> val0[0]val1[98066]
> > + * 9.806650000 ->exp:2-> val0[980]val1[665000000]
> > + * 9.000806000 ->exp:2-> val0[900]val1[80600000]
> > + * 0.174535293 ->exp:2-> val0[17]val1[453529300]
> > + * 1.001745329 ->exp:0-> val0[1]val1[1745329]
> > + * 1.001745329 ->exp:2-> val0[100]val1[174532900]
> > + * 1.001745329 ->exp:4-> val0[10017]val1[453290000]
> > + * 9.806650000 ->exp:-2-> val0[0]val1[98066500]
> > */
> > -static void adjust_exponent_micro(int *val0, int *val1, int
> > scale0,
> > +static void adjust_exponent_nano(int *val0, int *val1, int scale0,
> > int scale1, int exp)
> > {
> > int i;
> > @@ -285,32 +285,32 @@ static void adjust_exponent_micro(int *val0,
> > int *val1, int scale0,
> > if (exp > 0) {
> > *val0 = scale0 * pow_10(exp);
> > res = 0;
> > - if (exp > 6) {
> > + if (exp > 9) {
> > *val1 = 0;
> > return;
> > }
> > for (i = 0; i < exp; ++i) {
> > - x = scale1 / pow_10(5 - i);
> > + x = scale1 / pow_10(8 - i);
> > res += (pow_10(exp - 1 - i) * x);
> > - scale1 = scale1 % pow_10(5 - i);
> > + scale1 = scale1 % pow_10(8 - i);
> > }
> > *val0 += res;
> > *val1 = scale1 * pow_10(exp);
> > } else if (exp < 0) {
> > exp = abs(exp);
> > - if (exp > 6) {
> > + if (exp > 9) {
> > *val0 = *val1 = 0;
> > return;
> > }
> > *val0 = scale0 / pow_10(exp);
> > rem = scale0 % pow_10(exp);
> > res = 0;
> > - for (i = 0; i < (6 - exp); ++i) {
> > - x = scale1 / pow_10(5 - i);
> > - res += (pow_10(5 - exp - i) * x);
> > - scale1 = scale1 % pow_10(5 - i);
> > + for (i = 0; i < (9 - exp); ++i) {
> > + x = scale1 / pow_10(8 - i);
> > + res += (pow_10(8 - exp - i) * x);
> > + scale1 = scale1 % pow_10(8 - i);
> > }
> > - *val1 = rem * pow_10(6 - exp) + res;
> > + *val1 = rem * pow_10(9 - exp) + res;
> > } else {
> > *val0 = scale0;
> > *val1 = scale1;
> > @@ -332,14 +332,14 @@ int hid_sensor_format_scale(u32 usage_id,
> > unit_conversion[i].unit == attr_info-
> > >units) {
> > exp = hid_sensor_convert_exponent(
> > attr_info-
> > >unit_expo);
> > - adjust_exponent_micro(val0, val1,
> > + adjust_exponent_nano(val0, val1,
> > unit_conversion[i].scale_v
> > al0,
> > unit_conversion[i].scale_v
> > al1, exp);
> > break;
> > }
> > }
> >
> > - return IIO_VAL_INT_PLUS_MICRO;
> > + return IIO_VAL_INT_PLUS_NANO;
> > }
> > EXPORT_SYMBOL(hid_sensor_format_scale);
> >
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