drm/exynos: add G2D driver

Changelog v3:
- use __u64 instead of pointer in ioctl struct.

The G2D is a 2D graphic accelerator that supports Bit Block Transfer.
This G2D driver is exynos drm specific and supports only G2D(version
4.1) of later Exynos series from Exynos4X12 because supporting DMA.

The G2D is performed by two tasks simply.
1. Configures the rendering parameters, such as foreground color and
   coordinates data by setting the drawing context registers.
2. Start the rendering process by setting thre relevant command
   registers accordingly.

The G2D version 4.1 supports DMA mode as host interface. User can make
command list to reduce HOST(ARM) loads. The contents of The command list
is setted to relevant registers of G2D by DMA.

The command list is composed Header and command sets and Tail.
- Header: The number of command set(4Bytes)
- Command set: Register offset(4Bytes) + Register data(4Bytes)
- Tail: Pointer of base address of the other command list(4Bytes)

By Tail field, the G2D can process many command lists without halt at
one go.

The G2D has following the rendering pipeline.
--> Primitive Drawing --> Rotation --> Clipping --> Bilinear Sampling
--> Color Key --> ROP --> Mask Operation --> Alpha Blending -->
Dithering --> FrameBuffer

And supports various operations from the rendering pipeline.
- copy
- fast solid color fill
- window clipping
- rotation
- flip
- 4 operand raster operation(ROP4)
- masking operation
- alpha blending
- color key
- dithering
- etc

User should make the command list to data and registers needed by
operation to use. The Exynos G2D driver only manages the command lists
received from user. Some registers needs memory base address(physical
address) of image. User doesn't know its physical address, so fills the
gem handle of that memory than address to command sets, then G2D driver
converts it to memory base address.

We adds three ioctls and one event for Exynos G2D.

- ioctls
DRM_EXYNOS_G2D_GET_VER: get the G2D hardware version
DRM_EXYNOS_G2D_SET_CMDLIST: set the command list from user to driver
DRM_EXYNOS_G2D_EXEC: execute the command lists setted to driver

- event
DRM_EXYNOS_G2D_EVENT: event to give notification completion of the
		      command list to user

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

drivers/gpu/drm/exynos/Kconfig

@@ -33,3 +33,9 @@ config DRM_EXYNOS_VIDI
 	depends on DRM_EXYNOS
 	help
 	  Choose this option if you want to use Exynos VIDI for DRM.
+
+config DRM_EXYNOS_G2D
+	bool "Exynos DRM G2D"
+	depends on DRM_EXYNOS
+	help
+	  Choose this option if you want to use Exynos G2D for DRM.

drivers/gpu/drm/exynos/Makefile

@@ -14,5 +14,6 @@ exynosdrm-$(CONFIG_DRM_EXYNOS_HDMI)	+= exynos_hdmi.o exynos_mixer.o \
 					   exynos_ddc.o exynos_hdmiphy.o \
 					   exynos_drm_hdmi.o
 exynosdrm-$(CONFIG_DRM_EXYNOS_VIDI)	+= exynos_drm_vidi.o
+exynosdrm-$(CONFIG_DRM_EXYNOS_G2D)	+= exynos_drm_g2d.o
 
 obj-$(CONFIG_DRM_EXYNOS)		+= exynosdrm.o

drivers/gpu/drm/exynos/exynos_drm_drv.c

@@ -40,6 +40,7 @@
 #include "exynos_drm_plane.h"
 #include "exynos_drm_vidi.h"
 #include "exynos_drm_dmabuf.h"
+#include "exynos_drm_g2d.h"
 
 #define DRIVER_NAME	"exynos"
 #define DRIVER_DESC	"Samsung SoC DRM"
@@ -148,9 +149,16 @@ static int exynos_drm_unload(struct drm_device *dev)
 
 static int exynos_drm_open(struct drm_device *dev, struct drm_file *file)
 {
+	struct drm_exynos_file_private *file_priv;
+
 	DRM_DEBUG_DRIVER("%s\n", __FILE__);
 
+	file_priv = kzalloc(sizeof(*file_priv), GFP_KERNEL);
+	if (!file_priv)
+		return -ENOMEM;
+
 	drm_prime_init_file_private(&file->prime);
+	file->driver_priv = file_priv;
 
 	return exynos_drm_subdrv_open(dev, file);
 }
@@ -217,6 +225,12 @@ static struct drm_ioctl_desc exynos_ioctls[] = {
 			DRM_UNLOCKED | DRM_AUTH),
 	DRM_IOCTL_DEF_DRV(EXYNOS_VIDI_CONNECTION,
 			vidi_connection_ioctl, DRM_UNLOCKED | DRM_AUTH),
+	DRM_IOCTL_DEF_DRV(EXYNOS_G2D_GET_VER,
+			exynos_g2d_get_ver_ioctl, DRM_UNLOCKED | DRM_AUTH),
+	DRM_IOCTL_DEF_DRV(EXYNOS_G2D_SET_CMDLIST,
+			exynos_g2d_set_cmdlist_ioctl, DRM_UNLOCKED | DRM_AUTH),
+	DRM_IOCTL_DEF_DRV(EXYNOS_G2D_EXEC,
+			exynos_g2d_exec_ioctl, DRM_UNLOCKED | DRM_AUTH),
 };
 
 static const struct file_operations exynos_drm_driver_fops = {
@@ -317,13 +331,24 @@ static int __init exynos_drm_init(void)
 		goto out_vidi;
 #endif
 
+#ifdef CONFIG_DRM_EXYNOS_G2D
+	ret = platform_driver_register(&g2d_driver);
+	if (ret < 0)
+		goto out_g2d;
+#endif
+
 	ret = platform_driver_register(&exynos_drm_platform_driver);
 	if (ret < 0)
 		goto out;
 
 	return 0;
 
 out:
+#ifdef CONFIG_DRM_EXYNOS_G2D
+	platform_driver_unregister(&g2d_driver);
+out_g2d:
+#endif
+
 #ifdef CONFIG_DRM_EXYNOS_VIDI
 out_vidi:
 	platform_driver_unregister(&vidi_driver);
@@ -351,6 +376,10 @@ static void __exit exynos_drm_exit(void)
 
 	platform_driver_unregister(&exynos_drm_platform_driver);
 
+#ifdef CONFIG_DRM_EXYNOS_G2D
+	platform_driver_unregister(&g2d_driver);
+#endif
+
 #ifdef CONFIG_DRM_EXYNOS_HDMI
 	platform_driver_unregister(&exynos_drm_common_hdmi_driver);
 	platform_driver_unregister(&mixer_driver);

drivers/gpu/drm/exynos/exynos_drm_drv.h

@@ -209,6 +209,18 @@ struct exynos_drm_manager {
 	struct exynos_drm_display_ops *display_ops;
 };
 
+struct exynos_drm_g2d_private {
+	struct device		*dev;
+	struct list_head	inuse_cmdlist;
+	struct list_head	event_list;
+	struct list_head	gem_list;
+	unsigned int		gem_nr;
+};
+
+struct drm_exynos_file_private {
+	struct exynos_drm_g2d_private	*g2d_priv;
+};
+
 /*
  * Exynos drm private structure.
  */
@@ -291,4 +303,5 @@ extern struct platform_driver hdmi_driver;
 extern struct platform_driver mixer_driver;
 extern struct platform_driver exynos_drm_common_hdmi_driver;
 extern struct platform_driver vidi_driver;
+extern struct platform_driver g2d_driver;
 #endif