Date: Mon, 24 Feb 2003 13:35:11 +0800
From: "Leonidas"
Subject: [SDL] Re: Trigger mouse wheel event -- not in X-environment

I have looked into the codes for the IMPS/2 mouse wheel mode of fbcon driver.
But I found something weird.

Here's the original codes to set a mouse device into IMPS/2 mode in libSDL.
In the file src/video/fbcon/SDL_fbevents.c
In function static int set_imps2_mode(int fd)
...
 Uint8 set_imps2[] = {0xf3, 200, 0xf3, 100, 0xf3, 80};
 Uint8 reset = 0xff;
 fd_set fdset;
 struct timeval tv;
 int retval = 0;

 // Set mouse device fd into IMPS/2 mode
 if ( write(fd, &set_imps2, sizeof(set_imps2)) == sizeof(set_imps2) ) {
  // ??? then RESET it..???
  if (write(fd, &reset, sizeof (reset)) == sizeof (reset) ) {
   retval = 1;
  }
 }
...........

Since it sets IMPS/2 mode then reset it, so you will never get a mouse into
IMPS/2 mode to use its wheel.
What I did to make the wheel usable is remove the RESET codes.
....
 if ( write(fd, &set_imps2, sizeof(set_imps2)) == sizeof(set_imps2) ) {
    /*
    if (write(fd, &reset, sizeof (reset)) == sizeof (reset) ) {
    }
   */
   retval = 1;
 }
....
And in FB_OpenMouse(_THIS)
Make the device /dev/psaux to be setted into imps2 mode  such that it can be
detected its a imps/2 mouse or not.
(my mouse device is on ps2, but the codes only set /dev/input/mice device
originally)
Then I have done, I can use the mouse wheel when SDL uses frame buff driver.

I dont exactly know I did right or wrong, I just change it for my usuage.
Correct me please, if I did something wrong.

Best regards,
Li Tsung Lin
IAP Product Dept. Engineer
EeRise Corp. (Image Processing System, Computer Vision System)
Hsin Tien, Taipei Hsien, Taiwan, R.O.C.