From 6de58dd625a7645008c5c450bf97a5793faf58c3 Mon Sep 17 00:00:00 2001 From: Daniel Kurtz Date: Tue, 23 Aug 2011 23:00:24 -0700 Subject: [PATCH] Input: synaptics - refactor y inversion Synaptics touchpads report increasing y from bottom to top. This is inverted from normal userspace "top of screen is 0" coordinates. Thus, the kernel driver reports inverted y coordinates to userspace. This patch refactors this inversion. Signed-off-by: Daniel Kurtz Acked-by: Chase Douglas Acked-by: Henrik Rydberg Signed-off-by: Dmitry Torokhov --- drivers/input/mouse/synaptics.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c index 5538fc657af1..b0008bcb26fc 100644 --- a/drivers/input/mouse/synaptics.c +++ b/drivers/input/mouse/synaptics.c @@ -44,6 +44,16 @@ #define YMIN_NOMINAL 1408 #define YMAX_NOMINAL 4448 +/* + * Synaptics touchpads report the y coordinate from bottom to top, which is + * opposite from what userspace expects. + * This function is used to invert y before reporting. + */ +static int synaptics_invert_y(int y) +{ + return YMAX_NOMINAL + YMIN_NOMINAL - y; +} + /***************************************************************************** * Stuff we need even when we do not want native Synaptics support @@ -502,8 +512,7 @@ static void synaptics_report_semi_mt_slot(struct input_dev *dev, int slot, input_mt_report_slot_state(dev, MT_TOOL_FINGER, active); if (active) { input_report_abs(dev, ABS_MT_POSITION_X, x); - input_report_abs(dev, ABS_MT_POSITION_Y, - YMAX_NOMINAL + YMIN_NOMINAL - y); + input_report_abs(dev, ABS_MT_POSITION_Y, synaptics_invert_y(y)); } } @@ -597,7 +606,7 @@ static void synaptics_process_packet(struct psmouse *psmouse) if (num_fingers > 0) { input_report_abs(dev, ABS_X, hw.x); - input_report_abs(dev, ABS_Y, YMAX_NOMINAL + YMIN_NOMINAL - hw.y); + input_report_abs(dev, ABS_Y, synaptics_invert_y(hw.y)); } input_report_abs(dev, ABS_PRESSURE, hw.z); -- 2.20.1