drm: Add via unichrome support

Add DRM device driver for VIA Unichrome chipsets

From: Unichrome Project http://unichrome.sf.net, Erdi Chen, Thomas Hellstrom    Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/drm/via_video.c b/drivers/char/drm/via_video.c
new file mode 100644
index 0000000..37a61c6
--- /dev/null
+++ b/drivers/char/drm/via_video.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2005 Thomas Hellstrom. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sub license,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHOR(S), AND/OR THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Author: Thomas Hellstrom 2005.
+ *
+ * Video and XvMC related functions.
+ */
+
+#include "drmP.h"
+#include "via_drm.h"
+#include "via_drv.h"
+
+void
+via_init_futex(drm_via_private_t *dev_priv)
+{
+	unsigned int i;
+
+	DRM_DEBUG("%s\n", __FUNCTION__);
+
+	for (i = 0; i < VIA_NR_XVMC_LOCKS; ++i) {
+		DRM_INIT_WAITQUEUE(&(dev_priv->decoder_queue[i]));
+		XVMCLOCKPTR(dev_priv->sarea_priv, i)->lock = 0;
+	}
+}
+
+void
+via_cleanup_futex(drm_via_private_t *dev_priv)
+{
+}	
+
+void
+via_release_futex(drm_via_private_t *dev_priv, int context)
+{
+	unsigned int i;
+	volatile int *lock;
+
+	for (i=0; i < VIA_NR_XVMC_LOCKS; ++i) {
+	        lock = (int *) XVMCLOCKPTR(dev_priv->sarea_priv, i);
+		if ( (_DRM_LOCKING_CONTEXT( *lock ) == context)) {
+			if (_DRM_LOCK_IS_HELD( *lock ) && (*lock & _DRM_LOCK_CONT)) {
+				DRM_WAKEUP( &(dev_priv->decoder_queue[i]));
+			}
+			*lock = 0;
+		}
+	}	
+}	
+
+int 
+via_decoder_futex(DRM_IOCTL_ARGS)
+{
+	DRM_DEVICE;
+	drm_via_futex_t fx;
+	volatile int *lock;
+	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
+	drm_via_sarea_t *sAPriv = dev_priv->sarea_priv;
+	int ret = 0;
+
+	DRM_DEBUG("%s\n", __FUNCTION__);
+
+	DRM_COPY_FROM_USER_IOCTL(fx, (drm_via_futex_t *) data, sizeof(fx));
+
+	if (fx.lock > VIA_NR_XVMC_LOCKS)
+		return -EFAULT;
+
+	lock = (int *)XVMCLOCKPTR(sAPriv, fx.lock);
+
+	switch (fx.func) {
+	case VIA_FUTEX_WAIT:
+		DRM_WAIT_ON(ret, dev_priv->decoder_queue[fx.lock],
+			    (fx.ms / 10) * (DRM_HZ / 100), *lock != fx.val);
+		return ret;
+	case VIA_FUTEX_WAKE:
+		DRM_WAKEUP(&(dev_priv->decoder_queue[fx.lock]));
+		return 0;
+	}
+	return 0;
+}
+