From: Nikolai Kondrashov Date: Mon, 30 Aug 2010 10:06:38 +0000 (+0400) Subject: HID: waltop: comment on tablet modes X-Git-Tag: firefly_0821_release~7613^2~3667^2~1^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=cdd49a85e237929a4c00965f1a88bdd9195898d8;p=firefly-linux-kernel-4.4.55.git HID: waltop: comment on tablet modes Add a comment on modes supported by Waltop tablets - a knowledge extracted from the outdated official driver, but not yet used by this driver. Signed-off-by: Nikolai Kondrashov Signed-off-by: Jiri Kosina --- diff --git a/drivers/hid/hid-waltop.c b/drivers/hid/hid-waltop.c index 246160a9fb89..6ef9ed6a57d6 100644 --- a/drivers/hid/hid-waltop.c +++ b/drivers/hid/hid-waltop.c @@ -17,13 +17,38 @@ #include "hid-ids.h" +/* + * There exists an official driver on the manufacturer's website, which + * wasn't submitted to the kernel, for some reason. The official driver + * doesn't seem to support extra features of some tablets, like wheels. + * + * It shows that the feature report ID 2 could be used to control any waltop + * tablet input mode, switching it between "default", "tablet" and "ink". + * + * This driver only uses "default" mode for all the supported tablets. This + * mode tries to be HID-compatible (not very successfully), but cripples the + * resolution of some tablets. + * + * The "tablet" mode uses some proprietary, yet decipherable protocol, which + * represents the correct resolution, but is possibly HID-incompatible (i.e. + * indescribable by a report descriptor). + * + * The purpose of the "ink" mode is unknown. + * + * The feature reports needed for switching to each mode are these: + * + * 02 16 00 default + * 02 16 01 tablet + * 02 16 02 ink + */ + /* * Original Slim Tablet 5.8 inch report descriptor. * * All the reports except the report with ID 16 (the stylus) are unused, * possibly because the tablet is not configured to, or because they were - * just copied from a more capable model. The purpose of features described - * for report ID 2 is unknown. + * just copied from a more capable model. The full purpose of features + * described for report ID 2 is unknown. * * The stylus buttons are described as three bit fields, whereas actually * it's an "array", i.e. they're reported as button numbers (1, 2 and 3).