From: Jason Gerecke <jason.gerecke@xxxxxxxxx> Microsoft defines two slightly different behaviors for pens that are being used to erase. The first one, for pens that can be used while inverted specifies that both 'Invert' and 'Eraser' usages should be set while the pen is in contact and erasing. For pens that use an eraser button though, they specify that only the 'Eraser' usage should be set (while hovering, only the 'Invert' usage is to be set). We used our internal 'invert_state' flag to determine if a pen has an intent to erase (whether hovering or not). That flag was previously only depending on the 'Invert' usage, which was sufficient for the first type of pen (EMR) but not the second type (AES). This commit makes the flag depend on either usage being set, and also renames it to make its function more clear. This change should not normally have an impact on userspace due to both the existing driver and firmware design. The driver already only determines tool type based on the first event in an interaction (e.g. it will see the 'Invert' bit set when the eraser comes into prox and then report BTN_TOOL_RUBBER for the rest of the interaction, even if 'Invert' is cleared). AES firmware is also careful to send reports that work through a set of defined state transitions, even in the corner-case where the eraser button is pressed when the pen is already in contact with the display (Prox|Tip -> Prox -> 0 -> Invert -> Eraser). Regardless, it seems reasonable to ensure the driver's state variables match programmer expectation. Link: https://learn.microsoft.com/en-us/windows-hardware/design/component-guidelines/windows-pen-states Signed-off-by: Jason Gerecke <jason.gerecke@xxxxxxxxx> --- drivers/hid/wacom_wac.c | 7 +++++-- drivers/hid/wacom_wac.h | 2 +- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c index 413606bdf476d..fd0de9bae3d9a 100644 --- a/drivers/hid/wacom_wac.c +++ b/drivers/hid/wacom_wac.c @@ -2422,9 +2422,11 @@ static void wacom_wac_pen_event(struct hid_device *hdev, struct hid_field *field wacom_wac->hid_data.sense_state = value; return; case HID_DG_INVERT: - wacom_wac->hid_data.invert_state = value; + wacom_wac->hid_data.eraser |= value; return; case HID_DG_ERASER: + wacom_wac->hid_data.eraser |= value; + fallthrough; case HID_DG_TIPSWITCH: wacom_wac->hid_data.tipswitch |= value; return; @@ -2565,7 +2567,7 @@ static void wacom_wac_pen_report(struct hid_device *hdev, if (entering_range) { /* first in range */ /* Going into range select tool */ - if (wacom_wac->hid_data.invert_state) + if (wacom_wac->hid_data.eraser) wacom_wac->tool[0] = BTN_TOOL_RUBBER; else if (wacom_wac->features.quirks & WACOM_QUIRK_AESPEN) wacom_wac->tool[0] = BTN_TOOL_PEN; @@ -2619,6 +2621,7 @@ static void wacom_wac_pen_report(struct hid_device *hdev, } wacom_wac->hid_data.tipswitch = false; + wacom_wac->hid_data.eraser = false; input_sync(input); } diff --git a/drivers/hid/wacom_wac.h b/drivers/hid/wacom_wac.h index c8803d5c6a71e..0c3c6a6aaae95 100644 --- a/drivers/hid/wacom_wac.h +++ b/drivers/hid/wacom_wac.h @@ -300,7 +300,7 @@ struct hid_data { __s16 inputmode_index; /* InputMode HID feature index in the report */ bool sense_state; bool inrange_state; - bool invert_state; + bool eraser; bool tipswitch; bool barrelswitch; bool barrelswitch2; -- 2.47.0
