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author | Stefan Kriwanek <mail@stefankriwanek.de> | 2011-05-27 18:40:29 +0200 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2011-06-08 09:45:37 +0200 |
commit | 74bc6953135ae1478acc18046321bfca05b0e823 (patch) | |
tree | 194f288653928661abb8e8f88e07a19dd643210a /drivers/hid/hid-speedlink.c | |
parent | dc0a4f0ce2b1a9ef5947cdb6d62f60008a7e42bf (diff) | |
download | lwn-74bc6953135ae1478acc18046321bfca05b0e823.tar.gz lwn-74bc6953135ae1478acc18046321bfca05b0e823.zip |
HID: Add driver to fix Speedlink VAD Cezanne support
Speedlink VAD Cezanne have a hardware bug that makes the cursor "jump" from one
place to another every now and then. The issue are relative motion events
erroneously reported by the device, each having a distance value of +256. This
256 can in fact never occur due to real motion, therefore those events can
safely be ignored. The driver also drops useless EV_REL events with a value of
0, that the device sends every time it sends an "real" EV_REL or EV_KEY event.
Signed-off-by: Stefan Kriwanek <mail@stefankriwanek.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid/hid-speedlink.c')
-rw-r--r-- | drivers/hid/hid-speedlink.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/drivers/hid/hid-speedlink.c b/drivers/hid/hid-speedlink.c new file mode 100644 index 000000000000..602013741718 --- /dev/null +++ b/drivers/hid/hid-speedlink.c @@ -0,0 +1,89 @@ +/* + * HID driver for Speedlink Vicious and Divine Cezanne (USB mouse). + * Fixes "jumpy" cursor and removes nonexistent keyboard LEDS from + * the HID descriptor. + * + * Copyright (c) 2011 Stefan Kriwanek <mail@stefankriwanek.de> + */ + +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + */ + +#include <linux/device.h> +#include <linux/hid.h> +#include <linux/module.h> +#include <linux/usb.h> + +#include "hid-ids.h" +#include "usbhid/usbhid.h" + +static const struct hid_device_id speedlink_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_X_TENSIONS, USB_DEVICE_ID_SPEEDLINK_VAD_CEZANNE)}, + { } +}; + +static int speedlink_input_mapping(struct hid_device *hdev, + struct hid_input *hi, + struct hid_field *field, struct hid_usage *usage, + unsigned long **bit, int *max) +{ + /* + * The Cezanne mouse has a second "keyboard" USB endpoint for it is + * able to map keyboard events to the button presses. + * It sends a standard keyboard report descriptor, though, whose + * LEDs we ignore. + */ + switch (usage->hid & HID_USAGE_PAGE) { + case HID_UP_LED: + return -1; + } + return 0; +} + +static int speedlink_event(struct hid_device *hdev, struct hid_field *field, + struct hid_usage *usage, __s32 value) +{ + /* No other conditions due to usage_table. */ + /* Fix "jumpy" cursor (invalid events sent by device). */ + if (value == 256) + return 1; + /* Drop useless distance 0 events (on button clicks etc.) as well */ + if (value == 0) + return 1; + + return 0; +} + +MODULE_DEVICE_TABLE(hid, speedlink_devices); + +static const struct hid_usage_id speedlink_grabbed_usages[] = { + { HID_GD_X, EV_REL, 0 }, + { HID_GD_Y, EV_REL, 1 }, + { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1} +}; + +static struct hid_driver speedlink_driver = { + .name = "speedlink", + .id_table = speedlink_devices, + .usage_table = speedlink_grabbed_usages, + .input_mapping = speedlink_input_mapping, + .event = speedlink_event, +}; + +static int __init speedlink_init(void) +{ + return hid_register_driver(&speedlink_driver); +} + +static void __exit speedlink_exit(void) +{ + hid_unregister_driver(&speedlink_driver); +} + +module_init(speedlink_init); +module_exit(speedlink_exit); +MODULE_LICENSE("GPL"); |