[PATCH] HID: playstation: Remap joystick axes to be centered at 0
From: Siarhei Vishniakou <hidden>
Date: 2025-10-10 01:20:15
Also in:
lkml
Subsystem:
hid core layer, hid playstation driver, the rest · Maintainers:
Jiri Kosina, Benjamin Tissoires, Roderick Colenbrander, Linus Torvalds
The joystick axes (ABS_X, ABS_Y, ABS_RX, ABS_RY) for PlayStation gamepads report a neutral state of 128 over HID, with a full range of [0, 255]. The driver previously mapped this directly, resulting in an evdev range of [0, 255] with a resting point of 128. This approach is unconventional for Linux gamepad drivers and has several drawbacks: it requires userspace applications to be aware of the non-zero resting state, and it is incompatible with the input subsystem's 'flat' (deadzone) logic, which assumes a resting point of 0. This patch remaps the four joystick axes to the conventional signed 8-bit range of [-128, 127], with 0 as the neutral state. This is accomplished by changing their evdev range in ps_gamepad_create() and translating the incoming hardware value in the report parsing functions by subtracting 128. The analog trigger axes (ABS_Z, ABS_RZ) are handled separately. Their resting state is 0 (un-pressed), and their hardware range of [0, 255] is already the conventional representation. They are left unmodified by this patch. This makes the joystick behavior consistent with other gamepad drivers while preserving the standard behavior for the triggers. Signed-off-by: Siarhei Vishniakou <redacted> --- drivers/hid/hid-playstation.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c
index 1468fb11e39d..ca5bca9c2654 100644
--- a/drivers/hid/hid-playstation.c
+++ b/drivers/hid/hid-playstation.c@@ -718,11 +718,11 @@ static struct input_dev *ps_gamepad_create(struct hid_device *hdev, if (IS_ERR(gamepad)) return ERR_CAST(gamepad); - input_set_abs_params(gamepad, ABS_X, 0, 255, 0, 0); - input_set_abs_params(gamepad, ABS_Y, 0, 255, 0, 0); + input_set_abs_params(gamepad, ABS_X, -128, 127, 0, 0); + input_set_abs_params(gamepad, ABS_Y, -128, 127, 0, 0); input_set_abs_params(gamepad, ABS_Z, 0, 255, 0, 0); - input_set_abs_params(gamepad, ABS_RX, 0, 255, 0, 0); - input_set_abs_params(gamepad, ABS_RY, 0, 255, 0, 0); + input_set_abs_params(gamepad, ABS_RX, -128, 127, 0, 0); + input_set_abs_params(gamepad, ABS_RY, -128, 127, 0, 0); input_set_abs_params(gamepad, ABS_RZ, 0, 255, 0, 0); input_set_abs_params(gamepad, ABS_HAT0X, -1, 1, 0, 0);
@@ -1349,10 +1349,10 @@ static int dualsense_parse_report(struct ps_device *ps_dev, struct hid_report *r return -1; } - input_report_abs(ds->gamepad, ABS_X, ds_report->x); - input_report_abs(ds->gamepad, ABS_Y, ds_report->y); - input_report_abs(ds->gamepad, ABS_RX, ds_report->rx); - input_report_abs(ds->gamepad, ABS_RY, ds_report->ry); + input_report_abs(ds->gamepad, ABS_X, ds_report->x - 128); + input_report_abs(ds->gamepad, ABS_Y, ds_report->y - 128); + input_report_abs(ds->gamepad, ABS_RX, ds_report->rx - 128); + input_report_abs(ds->gamepad, ABS_RY, ds_report->ry - 128); input_report_abs(ds->gamepad, ABS_Z, ds_report->z); input_report_abs(ds->gamepad, ABS_RZ, ds_report->rz);
@@ -2272,10 +2272,10 @@ static int dualshock4_parse_report(struct ps_device *ps_dev, struct hid_report * return -1; } - input_report_abs(ds4->gamepad, ABS_X, ds4_report->x); - input_report_abs(ds4->gamepad, ABS_Y, ds4_report->y); - input_report_abs(ds4->gamepad, ABS_RX, ds4_report->rx); - input_report_abs(ds4->gamepad, ABS_RY, ds4_report->ry); + input_report_abs(ds4->gamepad, ABS_X, ds4_report->x - 128); + input_report_abs(ds4->gamepad, ABS_Y, ds4_report->y - 128); + input_report_abs(ds4->gamepad, ABS_RX, ds4_report->rx - 128); + input_report_abs(ds4->gamepad, ABS_RY, ds4_report->ry - 128); input_report_abs(ds4->gamepad, ABS_Z, ds4_report->z); input_report_abs(ds4->gamepad, ABS_RZ, ds4_report->rz);
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2.51.0.740.g6adb054d12-goog