[PATCH 4/4] Use mtdev to receive all events using MT Slots protocol

[Chase Douglas]

mtdev translates protocol A evdev devices into protocol B devices. We
just feed events through it to get what we want.

Hopefully someday the kernel will standardize on the MT Slots protocol
and we can remove this.

Signed-off-by: Chase Douglas <chase.douglas at canonical.com>
---
 configure.ac    |    6 ++++++
 src/Makefile.am |    2 +-
 src/evdev.c     |   33 +++++++++++++++++++++++++++++++--
 src/evdev.h     |    3 +++
 4 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index 63460b7..2b34b25 100644
--- a/configure.ac
+++ b/configure.ac
@@ -56,6 +56,12 @@ AC_ARG_WITH(xorg-module-dir,
 inputdir=${moduledir}/input
 AC_SUBST(inputdir)
 
+AC_ARG_WITH(mtdev,
+            AC_HELP_STRING([--with-mtdev],
+                           [Use mtdev library for multitouch evdev protocol translation [default=disabled]]),
+            [PKG_CHECK_MODULES(MTDEV, mtdev) AC_DEFINE(USE_MTDEV, 1, Whether to use mtdev or not)],
+            [AC_DEFINE(USE_MTDEV, 0, Whether to use mtdev or not)])
+
 # X Server SDK location is required to install evdev header files
 # This location is also relayed in the xorg-evdev.pc file
 sdkdir=`$PKG_CONFIG --variable=sdkdir xorg-server`
diff --git a/src/Makefile.am b/src/Makefile.am
index a5c89ac..caa36d2 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -29,7 +29,7 @@ AM_CFLAGS = $(XORG_CFLAGS) $(CWARNFLAGS)
 AM_CPPFLAGS =-I$(top_srcdir)/include
 
 @DRIVER_NAME at _drv_la_LTLIBRARIES = @DRIVER_NAME at _drv.la
- at DRIVER_NAME@_drv_la_LDFLAGS = -module -avoid-version
+ at DRIVER_NAME@_drv_la_LDFLAGS = -module -avoid-version @MTDEV_LIBS@
 @DRIVER_NAME at _drv_ladir = @inputdir@
 
 @DRIVER_NAME at _drv_la_SOURCES = @DRIVER_NAME at .c \
diff --git a/src/evdev.c b/src/evdev.c
index 777eebe..4564cdd 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -66,9 +66,13 @@
 #define MAXDEVICES MAX_DEVICES
 #endif
 
+#if USE_MTDEV
+#include <mtdev.h>
+#else
 #ifndef ABS_MT_SLOT
 #define ABS_MT_SLOT 0x2f
 #endif
+#endif /* USE_MTDEV */
 
 #define ArrayLength(a) (sizeof(a) / (sizeof((a)[0])))
 
@@ -750,7 +754,16 @@ EvdevReadInput(InputInfoPtr pInfo)
 
     while (len == sizeof(ev))
     {
-        len = read(pInfo->fd, &ev, sizeof(ev));
+#if USE_MTDEV
+        EvdevPtr pEvdev = pInfo->private;
+        if (pEvdev->mtdevPtr) {
+            len = mtdev_get(pEvdev->mtdevPtr, pInfo->fd, ev, NUM_EVENTS);
+            if (len > 0)
+                len *= sizeof(struct input_event);
+        }
+        else
+#endif /* USE_MTDEV */
+            len = read(pInfo->fd, &ev, sizeof(ev));
         if (len <= 0)
         {
             if (errno == ENODEV) /* May happen after resume */
@@ -1805,6 +1818,12 @@ EvdevProc(DeviceIntPtr device, int what)
             close(pInfo->fd);
             pInfo->fd = -1;
         }
+#if USE_MTDEV
+        if (pEvdev->mtdevPtr) {
+            mtdev_close(pEvdev->mtdevPtr);
+            free(pEvdev->mtdevPtr);
+        }
+#endif /* USE_MTDEV */
         EvdevRemoveDevice(pInfo);
         pEvdev->min_maj = 0;
 	break;
@@ -2093,13 +2112,23 @@ EvdevProbe(InputInfoPtr pInfo)
 
         if (TestBit(ABS_MT_POSITION_X, pEvdev->abs_bitmask) &&
             TestBit(ABS_MT_POSITION_Y, pEvdev->abs_bitmask) &&
-            TestBit(ABS_MT_SLOT, pEvdev->abs_bitmask)) {
+            (TestBit(ABS_MT_SLOT, pEvdev->abs_bitmask) || USE_MTDEV)) {
             xf86Msg(X_INFO, "%s: Found absolute multitouch device.\n", pInfo->name);
             pEvdev->flags |= EVDEV_MULTITOUCH;
             if (!pEvdev->num_buttons) {
                 pEvdev->num_buttons = 7; /* LMR + scroll wheels */
                 pEvdev->flags |= EVDEV_BUTTON_EVENTS;
             }
+
+#if USE_MTDEV
+            pEvdev->mtdevPtr = malloc(sizeof(struct mtdev));
+            if (!pEvdev->mtdevPtr || mtdev_open(pEvdev->mtdevPtr, pInfo->fd)) {
+                free(pEvdev->mtdevPtr);
+                pEvdev->mtdevPtr = NULL;
+                xf86Msg(X_WARNING, "%s: failed to initialize mtdev.\n",
+                        pInfo->name);
+            }
+#endif /* USE_MTDEV */
         }
         if ((TestBit(ABS_X, pEvdev->abs_bitmask) &&
              TestBit(ABS_Y, pEvdev->abs_bitmask))) {
diff --git a/src/evdev.h b/src/evdev.h
index 25c63a7..b528589 100644
--- a/src/evdev.h
+++ b/src/evdev.h
@@ -198,6 +198,9 @@ typedef struct {
     unsigned int mt_max_touchpoints; /* the number of simultaneous touchpoints
                                       * the device can support */
     unsigned int mt_current_touchpoint;
+#if USE_MTDEV
+    struct mtdev *mtdevPtr;
+#endif
 } EvdevRec, *EvdevPtr;
 
 /* Event posting functions */
-- 
1.7.0.4