[Patch-V2 3/6] HID:hid-logitech: Compute combined pedals value

[Simon Wood]

Add support for computing a combined accelerator/brake axis for wheels
which don't contain combined data in their HID stream.

This includes DFGT, G25, G27, G29 and Wii-Wheel.

Signed-off-by: Simon Wood <si...@mungewell.org>
---
 drivers/hid/hid-lg4ff.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index 79d34c2..cc5c9ebd 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -332,6 +332,7 @@ int lg4ff_adjust_input_event(struct hid_device *hid, struct 
hid_field *field,
 int lg4ff_raw_event(struct hid_device *hdev, struct hid_report *report,
                u8 *rd, int size, struct lg_drv_data *drv_data)
 {
+       int offset;
        struct lg4ff_device_entry *entry = drv_data->device_props;
 
        if (!entry)
@@ -353,9 +354,25 @@ int lg4ff_raw_event(struct hid_device *hdev, struct 
hid_report *report,
                        rd[5] = rd[4];
                        rd[6] = 0x7F;
                        return 1;
+               case USB_DEVICE_ID_LOGITECH_G25_WHEEL:
+               case USB_DEVICE_ID_LOGITECH_G27_WHEEL:
+                       offset = 5;
+                       break;
+               case USB_DEVICE_ID_LOGITECH_DFGT_WHEEL:
+               case USB_DEVICE_ID_LOGITECH_G29_WHEEL:
+                       offset = 6;
+                       break;
+               case USB_DEVICE_ID_LOGITECH_WII_WHEEL:
+                       offset = 3;
+                       break;
                default:
                        return 0;
                }
+
+               /* Compute a combined axis when wheel does not supply it */
+               rd[offset] = (0xFF + rd[offset] - rd[offset+1]) >> 1;
+               rd[offset+1] = 0x7F;
+               return 1;
        }
 
        return 0;
-- 
2.7.4