Re: [RFC][PATCH] USB touch screen driver, all-in-one

["Lanslott Gish" <lanslott.gish@gmail.com>]

On 3/16/06, Daniel Ritz <daniel.ritz-ml@swissonline.ch> wrote:
> On Wednesday 15 March 2006 05.30, Lanslott Gish wrote:
> > did you mean like that? thx.
> >
> > regards,
> >
> > Lanslott Gish
> > ===================================================================
> > --- linux-2.6.16-rc6.patched/drivers/usb/input/usbtouchscreen.c
> > +++ linux-2.6.16-rc6/drivers/usb/input/usbtouchscreen.c
> > @@ -49,6 +49,13 @@
> >  static int swap_xy;
> >  module_param(swap_xy, bool, 0644);
> >  MODULE_PARM_DESC(swap_xy, "If set X and Y axes are swapped.");
> > +static int swap_x;
> > +module_param(swap_x, bool, 0644);
> > +MODULE_PARM_DESC(swap_x, "If set X axe is swapped before XY swapped.");
> > +static int swap_y;
> > +module_param(swap_y, bool, 0644);
> > +MODULE_PARM_DESC(swap_y, "If set Y axe is swapped before XY swapped.");
> > +
> >
> (i prefer invert_x and invert_y...)
>
"invert" is great, thx.
evtouch(X11 driver) called these swap_x and swap_y

> >
> >  /* device specifc data/functions */
> > @@ -224,13 +231,17 @@
> >   * PanJit Part
> >   */
> >  #ifdef CONFIG_USB_TOUCHSCREEN_PANJIT
> > +
> >  static int panjit_read_data(char *pkt, int *x, int *y, int *touch, int *press)
> >  {
> > -       *x = pkt[1] | (pkt[2] << 8);
> > -       *y = pkt[3] | (pkt[4] << 8);
> > +       *x = (pkt[1] & 0x0F) | ((pkt[2]& 0xFF) << 8);
> > +       *y = (pkt[3] & 0x0F) | ((pkt[4]& 0xFF) << 8);
>
> that just can't be right. you probably mean
> +       *y = pkt[3] | ((pkt[4] & 0x0F) << 8);
>
> otherwise you mask out bits 4-7. but you want to limit it to 12 bits...
> (btw. no need for the & 0xFF mask since *pkt is char)
>

you are right, sorry for my fault. the truely way is

+       *x = (pkt[1] & 0xFF) | ((pkt[2] & 0x0F) << 8);
+       *y = (pkt[3] & 0xFF) | ((pkt[4] & 0x0F) << 8);

still need 12 bits( 0x0FFF) and the masks to avoid get negative.


BTW, may i also suggest add more module_param to max_x, max_y, min_x, min_y  ?
i think these options is useful, too.

regards,

Lanslott Gish
--
L.G, Life's Good~