drm: atmel-hlcdc: Add IOCTL to export the phy addr of gem

Added an IOCTL that exports the physical address of buffer to user space, so
the vdec in userspace can perform DMA operations.

Signed-off-by: Mohamed Jamsheeth Hajanajubudeen <mohamedjamsheeth.hajanajubudeen@atmel.com>

Author: Jamsheeth

drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c

@@ -26,6 +26,7 @@
 #include <linux/pm_runtime.h>
 
 #include "atmel_hlcdc_dc.h"
+#include <drm/atmel_drm.h>
 
 #define ATMEL_HLCDC_LAYER_IRQS_OFFSET		8
 
@@ -740,6 +741,41 @@ static void atmel_hlcdc_dc_irq_uninstall(struct drm_device *dev)
 
 DEFINE_DRM_GEM_CMA_FOPS(fops);
 
+/*
+ioctl to export the physical address of GEM to user space for
+video decoder
+*/
+int atmel_drm_gem_get_ioctl(struct drm_device *drm, void *data,
+				      struct drm_file *file_priv)
+{
+	struct drm_gem_object *gem_obj;
+	struct drm_gem_cma_object *cma_obj;
+	struct drm_mode_map_dumb *args = data;
+
+	mutex_lock(&drm->struct_mutex);
+
+	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+	if (!gem_obj) {
+		dev_err(drm->dev, "failed to lookup gem object\n");
+		mutex_unlock(&drm->struct_mutex);
+		return -EINVAL;
+	}
+
+	cma_obj = to_drm_gem_cma_obj(gem_obj);
+	args->offset = (__u64)cma_obj->paddr;
+
+	drm_gem_object_unreference(gem_obj);
+
+	mutex_unlock(&drm->struct_mutex);
+
+	return 0;
+}
+static const struct drm_ioctl_desc atmel_ioctls[] = {
+	DRM_IOCTL_DEF_DRV(ATMEL_GEM_GET, atmel_drm_gem_get_ioctl,
+			DRM_CONTROL_ALLOW|DRM_UNLOCKED),
+};
+
+
 static struct drm_driver atmel_hlcdc_dc_driver = {
 	.driver_features = DRIVER_HAVE_IRQ | DRIVER_GEM |
 			   DRIVER_MODESET | DRIVER_PRIME |
@@ -761,6 +797,8 @@ static struct drm_driver atmel_hlcdc_dc_driver = {
 	.gem_prime_vunmap = drm_gem_cma_prime_vunmap,
 	.gem_prime_mmap = drm_gem_cma_prime_mmap,
 	.dumb_create = drm_gem_cma_dumb_create,
+	.ioctls	= atmel_ioctls,
+	.num_ioctls= ARRAY_SIZE(atmel_ioctls),
 	.fops = &fops,
 	.name = "atmel-hlcdc",
 	.desc = "Atmel HLCD Controller DRM",

include/uapi/drm/atmel_drm.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2014 Atmel
+ *
+ * Author: Mohamed Jamsheeth <mohamedjamsheeth.hajanajubudeen@atmel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _UAPI_ATMEL_DRM_H_
+#define _UAPI_ATMEL_DRM_H_
+
+#include <drm/drm.h>
+
+#define DRM_ATMEL_GEM_GET		0x00
+
+#define DRM_IOCTL_ATMEL_GEM_GET		DRM_IOWR(DRM_COMMAND_BASE + \
+					DRM_ATMEL_GEM_GET, struct drm_mode_map_dumb)
+
+#endif /* _UAPI_ATMEL_DRM_H_ */