Re: add support for "crc_enabled" Elantech v3 touchpads

[Fasse]

On Wed, 1 Apr 2015 18:02:59 +0200
Stefan Sperling <s...@stsp.name> wrote:
> Interesting, thanks.
> 
> If you don't hear from anyone else about this please ask me again in
> a week from now. I can test on v3 hardware by then but not any earlier.
> 
> Please write this as if-else instead of switch:
> 
> > @@ -2271,11 +2284,18 @@ pms_proc_elantech_v3(struct pms_softc *s
> >              * and a tail packet. We report a single event and ignore
> >              * the tail packet.
> >              */
> > -           if ((sc->packet[0] & 0x0c) != 0x04 &&
> > -               (sc->packet[3] & 0xcf) != 0x02) {
> > -                   /* not the head packet -- ignore */
> > -                   return;
> > +           switch (elantech->flags & ELANTECH_F_CRC_ENABLED) {
> > +           case 0:
> > +                   if ((sc->packet[0] & 0x0c) != 0x04 &&
> > +                   (sc->packet[3] & 0xcf) != 0x02) {
> > +                           /* not the head packet -- ignore */
> > +                           return;
> > +                   }
> > +           case ELANTECH_F_CRC_ENABLED:
> > +                   if ((sc->packet[3] & 0x09) != 0x08)
> > +                           return;
> >             }

Thanks for the offer I will propably take you up on that.
Below is the modified diff with the switch statement transformed.

Index: sys/dev/pckbc/pms.c
===================================================================
RCS file: /cvs/src/sys/dev/pckbc/pms.c,v
retrieving revision 1.58
diff -u -p -r1.58 pms.c
--- sys/dev/pckbc/pms.c 26 Mar 2015 01:30:22 -0000      1.58
+++ sys/dev/pckbc/pms.c 1 Apr 2015 16:31:33 -0000
@@ -137,6 +137,7 @@ struct elantech_softc {
 #define ELANTECH_F_HAS_ROCKER          0x02
 #define ELANTECH_F_2FINGER_PACKET      0x04
 #define ELANTECH_F_HW_V1_OLD           0x08
+#define ELANTECH_F_CRC_ENABLED         0x10
        int fw_version;
 
        int min_x, min_y;
@@ -1812,6 +1813,9 @@ elantech_get_hwinfo_v3(struct pms_softc 
        elantech->fw_version = fw_version;
        elantech->flags |= ELANTECH_F_REPORTS_PRESSURE;
 
+       if ((fw_version & 0x4000) == 0x4000)
+               elantech->flags |= ELANTECH_F_CRC_ENABLED;
+
        if (elantech_set_absolute_mode_v3(sc))
                return (-1);
 
@@ -2164,14 +2168,23 @@ pms_sync_elantech_v2(struct pms_softc *s
 int
 pms_sync_elantech_v3(struct pms_softc *sc, int data)
 {
+       struct elantech_softc *elantech = sc->elantech;
+
        switch (sc->inputstate) {
        case 0:
+               if (elantech->flags & ELANTECH_F_CRC_ENABLED)
+                       break;
                if ((data & 0x0c) != 0x04 && (data & 0x0c) != 0x0c)
                        return (-1);
                break;
        case 3:
-               if ((data & 0xcf) != 0x02 && (data & 0xce) != 0x0c)
-                       return (-1);
+               if (elantech->flags & ELANTECH_F_CRC_ENABLED) {
+                       if ((data & 0x09) != 0x08 && (data & 0x09) != 0x09)
+                               return (-1);
+               } else {
+                       if ((data & 0xcf) != 0x02 && (data & 0xce) != 0x0c)
+                               return (-1);
+               }
                break;
        }
 
@@ -2271,10 +2284,15 @@ pms_proc_elantech_v3(struct pms_softc *s
                 * and a tail packet. We report a single event and ignore
                 * the tail packet.
                 */
-               if ((sc->packet[0] & 0x0c) != 0x04 &&
-                   (sc->packet[3] & 0xcf) != 0x02) {
-                       /* not the head packet -- ignore */
-                       return;
+               if (elantech->flags & ELANTECH_F_CRC_ENABLED) {
+                       if ((sc->packet[3] & 0x09) != 0x08)
+                               return;
+               } else {
+                       if ((sc->packet[0] & 0x0c) != 0x04 &&
+                       (sc->packet[3] & 0xcf) != 0x02) {
+                               /* not the head packet -- ignore */
+                               return;
+                       }
                }
        }