On 31/10/16 00:34, Pandruvada, Srinivas wrote:
> 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.
>
Again I've amended the patch title a touch to make it clear this is
a fix we really want in stable.
Applied to the togreg branch of iio.git and marked for stable.
Thanks,
Jonathan
> 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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