From e15944099870f374ca7efc62f98cf23ba272ef43 Mon Sep 17 00:00:00 2001 From: Ioan-Adrian Ratiu Date: Tue, 27 Sep 2016 21:41:38 +0300 Subject: [PATCH] HID: hid-dr: add input mapping for axis selection Commit 79346d620e9d ("HID: input: force generic axis to be mapped to their user space axis") made mapping generic axes to their userspace equivalents mandatory and some lower end gamepads which were depending on the previous behaviour suffered severe regressions because they were reusing axes and expecting hid-input to multiplex their map to the respective userspace axis by always searching for and using the next available axis. One solution is to add a hid quirk for this type of "previous" behaviour in hid-input to bypass the new axes policy in favour of the old one, but since only one hardware vendor seems to be affected negatively we're better off making and exception and mapping in the driver for now; if more vendors or drivers turn out to experience the problem we should reconsider the quirk solution. Signed-off-by: Ioan-Adrian Ratiu Reviewed-by: Benjamin Tissoires Signed-off-by: Jiri Kosina --- drivers/hid/hid-dr.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/drivers/hid/hid-dr.c b/drivers/hid/hid-dr.c index 8fd4bf77f264..0ed843939b2c 100644 --- a/drivers/hid/hid-dr.c +++ b/drivers/hid/hid-dr.c @@ -306,6 +306,30 @@ static __u8 *dr_report_fixup(struct hid_device *hdev, __u8 *rdesc, return rdesc; } +#define map_abs(c) hid_map_usage(hi, usage, bit, max, EV_ABS, (c)) +#define map_rel(c) hid_map_usage(hi, usage, bit, max, EV_REL, (c)) + +static int dr_input_mapping(struct hid_device *hdev, struct hid_input *hi, + struct hid_field *field, struct hid_usage *usage, + unsigned long **bit, int *max) +{ + switch (usage->hid) { + /* + * revert to the old hid-input behavior where axes + * can be randomly assigned when hid->usage is reused. + */ + case HID_GD_X: case HID_GD_Y: case HID_GD_Z: + case HID_GD_RX: case HID_GD_RY: case HID_GD_RZ: + if (field->flags & HID_MAIN_ITEM_RELATIVE) + map_rel(usage->hid & 0xf); + else + map_abs(usage->hid & 0xf); + return 1; + } + + return 0; +} + static int dr_probe(struct hid_device *hdev, const struct hid_device_id *id) { int ret; @@ -352,6 +376,7 @@ static struct hid_driver dr_driver = { .id_table = dr_devices, .report_fixup = dr_report_fixup, .probe = dr_probe, + .input_mapping = dr_input_mapping, }; module_hid_driver(dr_driver); -- 2.20.1