d91abc21e1
Remove cite "Not sure what this does, but it is absolutely essential". Extract initialization of trackstick part when touchpad is in passthrough mode for v3 and v6 protocols into own function. Initialization for v3 is: setscale11, setscale11, setscale11, nibble 0x9, nibble 0x4. Initialization for v6 is: setscale11, setscale11, setscale11, setrate 0xC8, setrate 0x14. Nibbles 0x9 and 0x4 for v3 protocol correspond to setrate 0xC8 and 0x14, therefore these sequences are same. When touchpad is in passthrough mode, then OS communicates with trackstick and this sequence is some magic vendor PS/2 command to put trackstick into "extended" mode. After that sequence trackstick starts reporting packets in some vendor 4 bytes format (first byte is always 0xE8). Next step after configuring trackstick to be in "extended" mode, is to configure touchpad for v3 protocol to expect that trackstick reports data in "extended" mode. For v3 protocol this is done by setting bit 1 in register 0xC2C8 (offset 0x08 from base address 0xC2C0). When both touchpad and trackstick are not configured for "extended" mode then touchpad reports trackstick packets in different format, which is not supported by psmouse/alps driver (yet). In Cirque documentation GP-AN- 130823 INTERFACING TO GEN4 OVER I2C (PDF) available at http://www.cirque.com/gen4-dev-resources is Logical Address 0xC2C8 named as PS2AuxControl and Bit Number 1 as ProcessAuxExtendedData with description: Auxiliary device data is assumed to be extended data when set. Signed-off-by: Pali Rohár <pali.rohar@gmail.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.