The wiimote motion plus gyros use two scales to report fast and slow rotation - below 440 deg/s uses 8192/440 units / deg/s, and above uses 8192/2000 units / deg/s. Previously this driver attempted to linearize the two by scaling the fast rate by 18 and the slow by 9, but this results in a scale of 8192*9/440 = ~167.564 for slow and 8192*18/2000 = 73.728 for fast. Correct the fast motion scale factor so that both report ~167.564 units / deg/s Signed-off-by: Cyan Ogilvie <cyan.ogilvie@xxxxxxxxx> --- drivers/hid/hid-wiimote-modules.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/hid/hid-wiimote-modules.c b/drivers/hid/hid-wiimote-modules.c index 4390eee..c830ed3 100644 --- a/drivers/hid/hid-wiimote-modules.c +++ b/drivers/hid/hid-wiimote-modules.c @@ -2049,9 +2049,11 @@ static void wiimod_mp_in_mp(struct wiimote_data *wdata, const __u8 *ext) * -----+------------------------------+-----+-----+ * The single bits Yaw, Roll, Pitch in the lower right corner specify * whether the wiimote is rotating fast (0) or slow (1). Speed for slow - * roation is 440 deg/s and for fast rotation 2000 deg/s. To get a - * linear scale we multiply by 2000/440 = ~4.5454 which is 18 for fast - * and 9 for slow. + * roation is 8192/440 units / deg/s and for fast rotation 8192/2000 + * units / deg/s. To get a linear scale for fast rotation we multiply + * by 2000/440 = ~4.5454 and scale both fast and slow by 9 to match the + * previous scale reported by this driver. + * This leaves a linear scale with 8192*9/440 (~167.564) units / deg/s. * If the wiimote is not rotating the sensor reports 2^13 = 8192. * Ext specifies whether an extension is connected to the motionp. * which is parsed by wiimote-core. @@ -2070,15 +2072,15 @@ static void wiimod_mp_in_mp(struct wiimote_data *wdata, const __u8 *ext) z -= 8192; if (!(ext[3] & 0x02)) - x *= 18; + x = (x * 2000 * 9) / 440; else x *= 9; if (!(ext[4] & 0x02)) - y *= 18; + y = (y * 2000 * 9) / 440; else y *= 9; if (!(ext[3] & 0x01)) - z *= 18; + z = (z * 2000 * 9) / 440; else z *= 9; -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
