From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ajay Kumar <ajaykumar.rs@samsung.com>
Subject: [RFC PATCH] drm/exynos: Add DECON driver
Date: Fri, 10 Oct 2014 18:18:36 +0530
Message-ID: <1412945316-26877-1-git-send-email-ajaykumar.rs@samsung.com>
Return-path: <linux-samsung-soc-owner@vger.kernel.org>
Sender: linux-samsung-soc-owner@vger.kernel.org
To: dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org
Cc: jy0922.shim@samsung.com, inki.dae@samsung.com, kgene.kim@samsung.com, seanpaul@google.com, ajaynumb@gmail.com, jg1.han@samsung.com, prashanth.g@samsung.com, Ajay Kumar <ajaykumar.rs@samsung.com>, Akshu Agrawal <akshu.a@samsung.com>
List-Id: devicetree@vger.kernel.org

This series is based on exynos-drm-next branch of Inki Dae's tree at:
git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos.git

DECON(Display and Enhancement Controller) is the new IP
in exynos7 SOC for generating video signals using pixel data.

DECON driver can be used to drive 2 different interfaces on Exynos7:
DECON-INT(video controller) and DECON-EXT(Mixer for HDMI)

The existing FIMD driver code was used as a template to create
DECON driver. Only DECON-INT is supported as of now, and
DECON-EXT support will be added later.

Signed-off-by: Akshu Agrawal <akshu.a@samsung.com>
Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
---
 .../devicetree/bindings/video/exynos-decon.txt     |   68 ++
 drivers/gpu/drm/exynos/Kconfig                     |   11 +-
 drivers/gpu/drm/exynos/Makefile                    |    1 +
 drivers/gpu/drm/exynos/exynos_drm_decon.c          | 1086 ++++++++++++++++++++
 drivers/gpu/drm/exynos/exynos_drm_drv.c            |   17 +-
 drivers/gpu/drm/exynos/exynos_drm_drv.h            |   11 +
 include/video/samsung_decon.h                      |  346 +++++++
 7 files changed, 1537 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/video/exynos-decon.txt
 create mode 100644 drivers/gpu/drm/exynos/exynos_drm_decon.c
 create mode 100644 include/video/samsung_decon.h

diff --git a/Documentation/devicetree/bindings/video/exynos-decon.txt b/Documentation/devicetree/bindings/video/exynos-decon.txt
new file mode 100644
index 0000000..e865650
--- /dev/null
+++ b/Documentation/devicetree/bindings/video/exynos-decon.txt
@@ -0,0 +1,68 @@
+Device-Tree bindings for Samsung Exynos7 SoC display controller (DECON)
+
+DECON (Display and Enhancement Controller) is the Display Controller for the
+Exynos7 series of SoCs which transfers the image data from a video memory
+buffer to an external LCD interface.
+
+Required properties:
+- compatible: value should be "samsung,exynos7-decon";
+
+- reg: physical base address and length of the DECON registers set.
+
+- interrupt-parent: should be the phandle of the decon controller's
+		parent interrupt controller.
+
+- interrupts: should contain a list of all DECON IP block interrupts in the
+		 order: FIFO Level, VSYNC, LCD_SYSTEM. The interrupt specifier
+		 format depends on the interrupt controller used.
+
+- interrupt-names: should contain the interrupt names: "fifo", "vsync",
+	"lcd_sys", in the same order as they were listed in the interrupts
+        property.
+
+- pinctrl-0: pin control group to be used for this controller.
+
+- pinctrl-names: must contain a "default" entry.
+
+- clocks: must include clock specifiers corresponding to entries in the
+         clock-names property.
+
+- clock-names: list of clock names sorted in the same order as the clocks
+               property. Must contain "pclk_decon0", "aclk_decon0",
+	       "decon0_eclk", "decon0_vclk", "sclk_dsd", aclk_lh_disp0",
+	       "aclk_disp", "aclk_lh_disp1".
+
+Optional Properties:
+- samsung,power-domain: a phandle to DECON power domain node.
+
+Example:
+
+SoC specific DT entry:
+
+	decon@13930000 {
+		compatible = "samsung,exynos7-decon";
+		interrupt-parent = <&combiner>;
+		reg = <0x13930000 0x1000>;
+		interrupt-names = "lcd_sys", "vsync", "fifo";
+		interrupts = <0 188 0>, <0 189 0>, <0 190 0>;
+		clocks = <&clock_disp PCLK_DECON_INT>,
+			 <&clock_disp ACLK_DECON_INT>,
+			 <&clock_disp SCLK_DECON_INT_ECLK>,
+			 <&clock_disp SCLK_DECON_INT_EXTCLKPLL>,
+			 <&clock_disp SCLK_DSD>,
+			 <&clock_bus0 ACLK_LH_DISP0>,
+			 <&clock_disp ACLK_CP_DISP>,
+			 <&clock_bus0 ACLK_LH_DISP1>;
+		clock-names = "pclk_decon0", "aclk_decon0", "decon0_eclk",
+				"decon0_vclk", "sclk_dsd", "aclk_lh_disp0",
+				"aclk_disp", "aclk_lh_disp1";
+		status = "disabled";
+	};
+
+Board specific DT entry:
+
+	decon@13930000 {
+		pinctrl-0 = <&lcd_clk &pwm1_out>;
+		pinctrl-names = "default";
+		status = "okay";
+	};
diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
index fd1c070..89275ea 100644
--- a/drivers/gpu/drm/exynos/Kconfig
+++ b/drivers/gpu/drm/exynos/Kconfig
@@ -31,6 +31,13 @@ config DRM_EXYNOS_FIMD
 	help
 	  Choose this option if you want to use Exynos FIMD for DRM.
 
+config DRM_EXYNOS_DECON
+	bool "Exynos DRM DECON"
+	depends on DRM_EXYNOS
+	select FB_MODE_HELPERS
+	help
+	  Choose this option if you want to use Exynos DECON for DRM.
+
 config DRM_EXYNOS_DPI
 	bool "EXYNOS DRM parallel output support"
 	depends on DRM_EXYNOS_FIMD
@@ -41,7 +48,7 @@ config DRM_EXYNOS_DPI
 
 config DRM_EXYNOS_DSI
 	bool "EXYNOS DRM MIPI-DSI driver support"
-	depends on DRM_EXYNOS_FIMD
+	depends on (DRM_EXYNOS_FIMD || DRM_EXYNOS_DECON)
 	select DRM_MIPI_DSI
 	select DRM_PANEL
 	default n
@@ -50,7 +57,7 @@ config DRM_EXYNOS_DSI
 
 config DRM_EXYNOS_DP
 	bool "EXYNOS DRM DP driver support"
-	depends on DRM_EXYNOS_FIMD && ARCH_EXYNOS && (DRM_PTN3460=n || DRM_PTN3460=y || DRM_PTN3460=DRM_EXYNOS)
+	depends on (DRM_EXYNOS_FIMD || DRM_EXYNOS_DECON) && ARCH_EXYNOS && (DRM_PTN3460=n || DRM_PTN3460=y || DRM_PTN3460=DRM_EXYNOS)
 	default DRM_EXYNOS
 	select DRM_PANEL
 	help
diff --git a/drivers/gpu/drm/exynos/Makefile b/drivers/gpu/drm/exynos/Makefile
index 33ae365..c3282ac 100644
--- a/drivers/gpu/drm/exynos/Makefile
+++ b/drivers/gpu/drm/exynos/Makefile
@@ -11,6 +11,7 @@ exynosdrm-y := exynos_drm_drv.o exynos_drm_encoder.o \
 exynosdrm-$(CONFIG_DRM_EXYNOS_IOMMU) += exynos_drm_iommu.o
 exynosdrm-$(CONFIG_DRM_EXYNOS_DMABUF) += exynos_drm_dmabuf.o
 exynosdrm-$(CONFIG_DRM_EXYNOS_FIMD)	+= exynos_drm_fimd.o
+exynosdrm-$(CONFIG_DRM_EXYNOS_DECON)	+= exynos_drm_decon.o
 exynosdrm-$(CONFIG_DRM_EXYNOS_DPI)	+= exynos_drm_dpi.o
 exynosdrm-$(CONFIG_DRM_EXYNOS_DSI)	+= exynos_drm_dsi.o
 exynosdrm-$(CONFIG_DRM_EXYNOS_DP)	+= exynos_dp_core.o exynos_dp_reg.o
diff --git a/drivers/gpu/drm/exynos/exynos_drm_decon.c b/drivers/gpu/drm/exynos/exynos_drm_decon.c
new file mode 100644
index 0000000..5ac4557
--- /dev/null
+++ b/drivers/gpu/drm/exynos/exynos_drm_decon.c
@@ -0,0 +1,1086 @@
+/* exynos_drm_decon.c
+ *
+ * Copyright (C) 2014 Samsung Electronics Co.Ltd
+ * Authors:
+ *	Akshu Agarwal <akshu.a@samsung.com>
+ *	Ajay Kumar <ajaykumar.rs@samsung.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ */
+#include <drm/drmP.h>
+#include <drm/exynos_drm.h>
+
+#include <linux/clk.h>
+#include <linux/component.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include <video/of_display_timing.h>
+#include <video/of_videomode.h>
+#include <video/samsung_decon.h>
+
+#include "exynos_drm_crtc.h"
+#include "exynos_drm_drv.h"
+#include "exynos_drm_fbdev.h"
+#include "exynos_drm_iommu.h"
+
+/*
+ * DECON stands for Display and Enhancement controller, and
+ * as a display controller, it transfers contents drawn on memory
+ * to a LCD Panel through Display Interfaces such as RGB or
+ * CPU Interface.
+ */
+
+#define DECON_DEFAULT_FRAMERATE 60
+#define RESET_TIMEOUT 200
+#define MIN_FB_WIDTH_FOR_16WORD_BURST 128
+
+#define WINDOWS_NR	2
+
+#define get_decon_manager(mgr)	platform_get_drvdata(to_platform_device(dev))
+
+struct decon_win_data {
+	unsigned int		ovl_x;
+	unsigned int		ovl_y;
+	unsigned int		offset_x;
+	unsigned int		offset_y;
+	unsigned int		ovl_width;
+	unsigned int		ovl_height;
+	unsigned int		fb_width;
+	unsigned int		fb_height;
+	unsigned int		bpp;
+	unsigned int		pixel_format;
+	dma_addr_t		dma_addr;
+	bool			enabled;
+	bool			resume;
+};
+
+struct decon_context {
+	struct device			*dev;
+	struct drm_device		*drm_dev;
+	struct clk			*pclk;
+	struct clk			*aclk;
+	struct clk			*eclk;
+	struct clk			*vclk;
+	struct clk			*dsd;
+	struct clk			*lh_disp1;
+	struct clk			*aclk_disp;
+	struct clk			*lh_disp0;
+	void __iomem			*regs;
+	struct drm_display_mode		mode;
+	struct decon_win_data		win_data[WINDOWS_NR];
+	unsigned int			default_win;
+	unsigned long			irq_flags;
+	u32				vidcon1;
+	bool				suspended;
+	int				pipe;
+	wait_queue_head_t		wait_vsync_queue;
+	atomic_t			wait_vsync_event;
+
+	struct exynos_drm_panel_info panel;
+};
+
+static const struct of_device_id decon_driver_dt_match[] = {
+	{ .compatible = "samsung,exynos7-decon"},
+	{},
+};
+MODULE_DEVICE_TABLE(of, decon_driver_dt_match);
+
+static void decon_wait_for_vblank(struct exynos_drm_manager *mgr)
+{
+	struct decon_context *ctx = mgr->ctx;
+
+	if (ctx->suspended)
+		return;
+
+	atomic_set(&ctx->wait_vsync_event, 1);
+
+	/*
+	 * wait for decon to signal VSYNC interrupt or return after
+	 * timeout which is set to 50ms (refresh rate of 20).
+	 */
+	if (!wait_event_timeout(ctx->wait_vsync_queue,
+				!atomic_read(&ctx->wait_vsync_event),
+				HZ/20))
+		DRM_DEBUG_KMS("vblank wait timed out.\n");
+}
+
+static void decon_clear_channel(struct exynos_drm_manager *mgr)
+{
+	struct decon_context *ctx = mgr->ctx;
+	int win, ch_enabled = 0;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	/* Check if any channel is enabled. */
+	for (win = 0; win < WINDOWS_NR; win++) {
+		u32 val = readl(ctx->regs + WINCON(win));
+
+		if (val & WINCONx_ENWIN) {
+			val &= ~WINCONx_ENWIN;
+			writel(val, ctx->regs + WINCON(win));
+			ch_enabled = 1;
+		}
+	}
+
+	/* Wait for vsync, as disable channel takes effect at next vsync */
+	if (ch_enabled) {
+		unsigned int state = ctx->suspended;
+
+		ctx->suspended = 0;
+		decon_wait_for_vblank(mgr);
+		ctx->suspended = state;
+	}
+}
+
+static int decon_mgr_initialize(struct exynos_drm_manager *mgr,
+			struct drm_device *drm_dev)
+{
+	struct decon_context *ctx = mgr->ctx;
+	struct exynos_drm_private *priv = drm_dev->dev_private;
+
+	mgr->drm_dev = ctx->drm_dev = drm_dev;
+	mgr->pipe = ctx->pipe = priv->pipe++;
+
+	/* attach this sub driver to iommu mapping if supported. */
+	if (is_drm_iommu_supported(ctx->drm_dev)) {
+		/*
+		 * If any channel is already active, iommu will throw
+		 * a PAGE FAULT when enabled. So clear any channel if enabled.
+		 */
+		decon_clear_channel(mgr);
+		drm_iommu_attach_device(ctx->drm_dev, ctx->dev);
+	}
+
+	return 0;
+}
+
+static void decon_mgr_remove(struct exynos_drm_manager *mgr)
+{
+	struct decon_context *ctx = mgr->ctx;
+
+	/* detach this sub driver from iommu mapping if supported. */
+	if (is_drm_iommu_supported(ctx->drm_dev))
+		drm_iommu_detach_device(ctx->drm_dev, ctx->dev);
+}
+
+static u32 decon_calc_clkdiv(struct decon_context *ctx,
+		const struct drm_display_mode *mode)
+{
+	unsigned long ideal_clk = mode->htotal * mode->vtotal * mode->vrefresh;
+	u32 clkdiv;
+
+	/* Find the clock divider value that gets us closest to ideal_clk */
+	clkdiv = DIV_ROUND_UP(clk_get_rate(ctx->vclk), ideal_clk);
+
+	return (clkdiv < 0x100) ? clkdiv : 0xff;
+}
+
+static bool decon_mode_fixup(struct exynos_drm_manager *mgr,
+		const struct drm_display_mode *mode,
+		struct drm_display_mode *adjusted_mode)
+{
+	if (adjusted_mode->vrefresh == 0)
+		adjusted_mode->vrefresh = DECON_DEFAULT_FRAMERATE;
+
+	return true;
+}
+
+static void decon_mode_set(struct exynos_drm_manager *mgr,
+		const struct drm_display_mode *in_mode)
+{
+	struct decon_context *ctx = mgr->ctx;
+
+	drm_mode_copy(&ctx->mode, in_mode);
+}
+
+static void decon_commit(struct exynos_drm_manager *mgr)
+{
+	struct decon_context *ctx = mgr->ctx;
+	struct drm_display_mode *mode = &ctx->mode;
+	u32 val, clkdiv;
+	int vsync_len, vbpd, vfpd, hsync_len, hbpd, hfpd;
+
+	if (ctx->suspended)
+		return;
+
+	/* nothing to do if we haven't set the mode yet */
+	if (mode->htotal == 0 || mode->vtotal == 0)
+		return;
+
+      /* setup vertical timing values. */
+	vsync_len = mode->crtc_vsync_end - mode->crtc_vsync_start;
+	vbpd = mode->crtc_vtotal - mode->crtc_vsync_end;
+	vfpd = mode->crtc_vsync_start - mode->crtc_vdisplay;
+
+	val = VIDTCON0_VBPD(vbpd - 1) | VIDTCON0_VFPD(vfpd - 1);
+	writel(val, ctx->regs + VIDTCON0);
+
+	val = VIDTCON1_VSPW(vsync_len - 1);
+	writel(val, ctx->regs + VIDTCON1);
+
+	/* setup horizontal timing values.  */
+	hsync_len = mode->crtc_hsync_end - mode->crtc_hsync_start;
+	hbpd = mode->crtc_htotal - mode->crtc_hsync_end;
+	hfpd = mode->crtc_hsync_start - mode->crtc_hdisplay;
+
+	/* setup horizontal timing values.  */
+	val = VIDTCON2_HBPD(hbpd - 1) | VIDTCON2_HFPD(hfpd - 1);
+	writel(val, ctx->regs + VIDTCON2);
+
+	val = VIDTCON3_HSPW(hsync_len - 1);
+	writel(val, ctx->regs + VIDTCON3);
+
+	/* setup horizontal and vertical display size. */
+	val = VIDTCON4_LINEVAL(mode->vdisplay - 1) |
+	       VIDTCON4_HOZVAL(mode->hdisplay - 1);
+	writel(val, ctx->regs + VIDTCON4);
+
+	writel(mode->vdisplay - 1, ctx->regs + LINECNT_OP_THRESHOLD);
+
+	/*
+	 * fields of register with prefix '_F' would be updated
+	 * at vsync(same as dma start)
+	 */
+	val = VIDCON0_ENVID | VIDCON0_ENVID_F;
+	writel(val, ctx->regs + VIDCON0);
+
+	clkdiv = decon_calc_clkdiv(ctx, mode);
+	if (clkdiv > 1) {
+		val = VCLKCON1_CLKVAL_NUM_VCLK(clkdiv - 1);
+		writel(val, ctx->regs + VCLKCON1);
+		writel(val, ctx->regs + VCLKCON2);
+	}
+
+	val = readl(ctx->regs + DECON_UPDATE);
+	val |= DECON_UPDATE_STANDALONE_F;
+	writel(val, ctx->regs + DECON_UPDATE);
+}
+
+static int decon_enable_vblank(struct exynos_drm_manager *mgr)
+{
+	struct decon_context *ctx = mgr->ctx;
+	u32 val;
+
+	if (ctx->suspended)
+		return -EPERM;
+
+	if (!test_and_set_bit(0, &ctx->irq_flags)) {
+		val = readl(ctx->regs + VIDINTCON0);
+
+		val |= VIDINTCON0_INT_ENABLE;
+		val |= VIDINTCON0_INT_FRAME;
+
+		val &= ~VIDINTCON0_FRAMESEL0_MASK;
+		val |= VIDINTCON0_FRAMESEL0_VSYNC;
+
+		writel(val, ctx->regs + VIDINTCON0);
+	}
+
+	return 0;
+}
+
+static void decon_disable_vblank(struct exynos_drm_manager *mgr)
+{
+	struct decon_context *ctx = mgr->ctx;
+	u32 val;
+
+	if (ctx->suspended)
+		return;
+
+	if (test_and_clear_bit(0, &ctx->irq_flags)) {
+		val = readl(ctx->regs + VIDINTCON0);
+
+		val &= ~VIDINTCON0_INT_FRAME;
+		val &= ~VIDINTCON0_INT_ENABLE;
+
+		writel(val, ctx->regs + VIDINTCON0);
+	}
+}
+
+static void decon_win_mode_set(struct exynos_drm_manager *mgr,
+			struct exynos_drm_overlay *overlay)
+{
+	struct decon_context *ctx = mgr->ctx;
+	struct decon_win_data *win_data;
+	int win, padding;
+
+	if (!overlay) {
+		DRM_ERROR("overlay is NULL\n");
+		return;
+	}
+
+	win = overlay->zpos;
+	if (win == DEFAULT_ZPOS)
+		win = ctx->default_win;
+
+	if (win < 0 || win >= WINDOWS_NR)
+		return;
+
+
+	win_data = &ctx->win_data[win];
+
+	padding = (overlay->pitch / (overlay->bpp >> 3)) - overlay->fb_width;
+	win_data->offset_x = overlay->fb_x;
+	win_data->offset_y = overlay->fb_y;
+	win_data->fb_width = overlay->fb_width + padding;
+	win_data->fb_height = overlay->fb_height;
+	win_data->ovl_x = overlay->crtc_x;
+	win_data->ovl_y = overlay->crtc_y;
+	win_data->ovl_width = overlay->crtc_width;
+	win_data->ovl_height = overlay->crtc_height;
+	win_data->dma_addr = overlay->dma_addr[0];
+	win_data->bpp = overlay->bpp;
+	win_data->pixel_format = overlay->pixel_format;
+
+	DRM_DEBUG_KMS("offset_x = %d, offset_y = %d\n",
+			win_data->offset_x, win_data->offset_y);
+	DRM_DEBUG_KMS("ovl_width = %d, ovl_height = %d\n",
+			win_data->ovl_width, win_data->ovl_height);
+	DRM_DEBUG_KMS("paddr = 0x%lx\n", (unsigned long)win_data->dma_addr);
+	DRM_DEBUG_KMS("fb_width = %d, crtc_width = %d\n",
+			overlay->fb_width, overlay->crtc_width);
+}
+
+static void decon_win_set_pixfmt(struct decon_context *ctx, unsigned int win)
+{
+	struct decon_win_data *win_data = &ctx->win_data[win];
+	unsigned long val;
+
+	val = readl(ctx->regs + WINCON(win));
+	val &= ~WINCONx_BPPMODE_MASK;
+
+	switch (win_data->pixel_format) {
+	case DRM_FORMAT_RGB565:
+		val |= WINCONx_BPPMODE_16BPP_565;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	case DRM_FORMAT_XRGB8888:
+		val |= WINCONx_BPPMODE_24BPP_xRGB;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	case DRM_FORMAT_XBGR8888:
+		val |= WINCONx_BPPMODE_24BPP_xBGR;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	case DRM_FORMAT_RGBX8888:
+		val |= WINCONx_BPPMODE_24BPP_RGBx;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	case DRM_FORMAT_BGRX8888:
+		val |= WINCONx_BPPMODE_24BPP_BGRx;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	case DRM_FORMAT_ARGB8888:
+		val |= WINCONx_BPPMODE_32BPP_ARGB | WINCONx_BLD_PIX |
+			WINCONx_ALPHA_SEL;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	case DRM_FORMAT_ABGR8888:
+		val |= WINCONx_BPPMODE_32BPP_ABGR | WINCONx_BLD_PIX |
+			WINCONx_ALPHA_SEL;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	case DRM_FORMAT_RGBA8888:
+		val |= WINCONx_BPPMODE_32BPP_RGBA | WINCONx_BLD_PIX |
+			WINCONx_ALPHA_SEL;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	case DRM_FORMAT_BGRA8888:
+		val |= WINCONx_BPPMODE_32BPP_BGRA | WINCONx_BLD_PIX |
+			WINCONx_ALPHA_SEL;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	default:
+		DRM_DEBUG_KMS("invalid pixel size so using unpacked 24bpp.\n");
+
+		val |= WINCONx_BPPMODE_24BPP_xRGB;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	}
+
+	DRM_DEBUG_KMS("bpp = %d\n", win_data->bpp);
+
+	/*
+	 * In case of exynos, setting dma-burst to 16Word causes permanent
+	 * tearing for very small buffers, e.g. cursor buffer. Burst Mode
+	 * switching which is based on overlay size is not recommended as
+	 * overlay size varies alot towards the end of the screen and rapid
+	 * movement causes unstable DMA which results into iommu crash/tear.
+	 */
+
+	if (win_data->fb_width < MIN_FB_WIDTH_FOR_16WORD_BURST) {
+		val &= ~WINCONx_BURSTLEN_MASK;
+		val |= WINCONx_BURSTLEN_8WORD;
+	}
+
+	writel(val, ctx->regs + WINCON(win));
+}
+
+static void decon_win_set_colkey(struct decon_context *ctx, unsigned int win)
+{
+	unsigned int keycon0 = 0, keycon1 = 0;
+
+	keycon0 = ~(WxKEYCON0_KEYBL_EN | WxKEYCON0_KEYEN_F |
+			WxKEYCON0_DIRCON) | WxKEYCON0_COMPKEY(0);
+
+	keycon1 = WxKEYCON1_COLVAL(0xffffffff);
+
+	writel(keycon0, ctx->regs + WKEYCON0_BASE(win));
+	writel(keycon1, ctx->regs + WKEYCON1_BASE(win));
+}
+
+/**
+ * shadow_protect_win() - disable updating values from shadow registers at vsync
+ *
+ * @win: window to protect registers for
+ * @protect: 1 to protect (disable updates)
+ */
+static void decon_shadow_protect_win(struct decon_context *ctx,
+							int win, bool protect)
+{
+	u32 reg, bits, val;
+
+	reg = SHADOWCON;
+	bits = SHADOWCON_WINx_PROTECT(win);
+
+	val = readl(ctx->regs + reg);
+	if (protect)
+		val |= bits;
+	else
+		val &= ~bits;
+	writel(val, ctx->regs + reg);
+}
+
+static void decon_win_commit(struct exynos_drm_manager *mgr, int zpos)
+{
+	struct decon_context *ctx = mgr->ctx;
+	struct decon_win_data *win_data;
+	int win = zpos;
+	unsigned long val, alpha, blendeq;
+	unsigned int last_x;
+	unsigned int last_y;
+
+	if (ctx->suspended)
+		return;
+
+	if (win == DEFAULT_ZPOS)
+		win = ctx->default_win;
+
+	if (win < 0 || win >= WINDOWS_NR)
+		return;
+
+	win_data = &ctx->win_data[win];
+
+	/* If suspended, enable this on resume */
+	if (ctx->suspended) {
+		win_data->resume = true;
+		return;
+	}
+
+	/*
+	 * SHADOWCON/PRTCON register is used for enabling timing.
+	 *
+	 * for example, once only width value of a register is set,
+	 * if the dma is started then decon hardware could malfunction so
+	 * with protect window setting, the register fields with prefix '_F'
+	 * wouldn't be updated at vsync also but updated once unprotect window
+	 * is set.
+	 */
+
+	/* protect windows */
+	decon_shadow_protect_win(ctx, win, true);
+
+	/* buffer start address */
+	val = (unsigned long)win_data->dma_addr;
+	writel(val, ctx->regs + VIDW_BUF_START(win));
+
+	/* buffer size */
+	writel(win_data->fb_width, ctx->regs + VIDW_WHOLE_X(win));
+	writel(win_data->fb_height, ctx->regs + VIDW_WHOLE_Y(win));
+
+	/* offset from the start of the buffer read */
+	writel(win_data->offset_x, ctx->regs + VIDW_OFFSET_X(win));
+	writel(win_data->offset_y, ctx->regs + VIDW_OFFSET_Y(win));
+
+	DRM_DEBUG_KMS("start addr = 0x%lx\n",
+			(unsigned long)win_data->dma_addr);
+	DRM_DEBUG_KMS("ovl_width = %d, ovl_height = %d\n",
+			win_data->ovl_width, win_data->ovl_height);
+
+	/* OSD position */
+	val = VIDOSDxA_TOPLEFT_X(win_data->ovl_x) |
+		VIDOSDxA_TOPLEFT_Y(win_data->ovl_y);
+	writel(val, ctx->regs + VIDOSD_A(win));
+
+	last_x = win_data->ovl_x + win_data->ovl_width;
+	if (last_x)
+		last_x--;
+	last_y = win_data->ovl_y + win_data->ovl_height;
+	if (last_y)
+		last_y--;
+
+	val = VIDOSDxB_BOTRIGHT_X(last_x) | VIDOSDxB_BOTRIGHT_Y(last_y);
+
+	writel(val, ctx->regs + VIDOSD_B(win));
+
+	DRM_DEBUG_KMS("osd pos: tx = %d, ty = %d, bx = %d, by = %d\n",
+			win_data->ovl_x, win_data->ovl_y, last_x, last_y);
+
+		/* OSD alpha */
+		alpha = VIDOSDxC_ALPHA0_R_F(0x0) |
+				VIDOSDxC_ALPHA0_G_F(0x0) |
+				VIDOSDxC_ALPHA0_B_F(0x0);
+
+		writel(alpha, ctx->regs + VIDOSD_C(win));
+
+		alpha = VIDOSDxD_ALPHA1_R_F(0xff) |
+				VIDOSDxD_ALPHA1_G_F(0xff) |
+				VIDOSDxD_ALPHA1_B_F(0xff);
+
+		writel(alpha, ctx->regs + VIDOSD_D(win));
+
+	if (win != 0) {
+		blendeq = BLENDE_A_FUNC(BLENDE_COEF_ONE) |
+			BLENDE_B_FUNC(BLENDE_COEF_ZERO) |
+			BLENDE_P_FUNC(BLENDE_COEF_ZERO) |
+			BLENDE_Q_FUNC(BLENDE_COEF_ZERO);
+
+		writel(blendeq, ctx->regs + BLENDE(win - 1));
+	}
+
+	decon_win_set_pixfmt(ctx, win);
+
+	/* hardware window 0 doesn't support color key. */
+	if (win != 0)
+		decon_win_set_colkey(ctx, win);
+
+	/* wincon */
+	val = readl(ctx->regs + WINCON(win));
+	val |= WINCONx_TRIPLE_BUF_MODE;
+	val |= WINCONx_ENWIN;
+	writel(val, ctx->regs + WINCON(win));
+
+	/* Enable DMA channel and unprotect windows */
+	decon_shadow_protect_win(ctx, win, false);
+
+	val = readl(ctx->regs + DECON_UPDATE);
+	val |= DECON_UPDATE_STANDALONE_F;
+	writel(val, ctx->regs + DECON_UPDATE);
+
+	win_data->enabled = true;
+}
+
+static void decon_win_disable(struct exynos_drm_manager *mgr, int zpos)
+{
+	struct decon_context *ctx = mgr->ctx;
+	struct decon_win_data *win_data;
+	int win = zpos;
+	u32 val;
+
+	if (win == DEFAULT_ZPOS)
+		win = ctx->default_win;
+
+	if (win < 0 || win >= WINDOWS_NR)
+		return;
+
+	win_data = &ctx->win_data[win];
+
+	if (ctx->suspended) {
+		/* do not resume this window*/
+		win_data->resume = false;
+		return;
+	}
+
+	/* protect windows */
+	decon_shadow_protect_win(ctx, win, true);
+
+	/* wincon */
+	val = readl(ctx->regs + WINCON(win));
+	val &= ~WINCONx_ENWIN;
+	writel(val, ctx->regs + WINCON(win));
+
+	decon_shadow_protect_win(ctx, win, false);
+
+	win_data->enabled = false;
+}
+
+static void decon_window_suspend(struct exynos_drm_manager *mgr)
+{
+	struct decon_context *ctx = mgr->ctx;
+	struct decon_win_data *win_data;
+	int i;
+
+	for (i = 0; i < WINDOWS_NR; i++) {
+		win_data = &ctx->win_data[i];
+		win_data->resume = win_data->enabled;
+		if (win_data->enabled)
+			decon_win_disable(mgr, i);
+	}
+	decon_wait_for_vblank(mgr);
+}
+
+static void decon_window_resume(struct exynos_drm_manager *mgr)
+{
+	struct decon_context *ctx = mgr->ctx;
+	struct decon_win_data *win_data;
+	int i;
+
+	for (i = 0; i < WINDOWS_NR; i++) {
+		win_data = &ctx->win_data[i];
+		win_data->enabled = win_data->resume;
+		win_data->resume = false;
+	}
+}
+
+static void decon_apply(struct exynos_drm_manager *mgr)
+{
+	struct decon_context *ctx = mgr->ctx;
+	struct decon_win_data *win_data;
+	int i;
+
+	for (i = 0; i < WINDOWS_NR; i++) {
+		win_data = &ctx->win_data[i];
+		if (win_data->enabled)
+			decon_win_commit(mgr, i);
+		else
+			decon_win_disable(mgr, i);
+	}
+
+	decon_commit(mgr);
+}
+
+static int decon_reg_reset(struct decon_context *ctx)
+{
+	int tries = RESET_TIMEOUT;
+
+	writel(VIDCON0_SWRESET, ctx->regs + VIDCON0);
+
+	while (tries) {
+		if (!(readl(ctx->regs + VIDCON0) & VIDCON0_SWRESET))
+			break;
+		udelay(10);
+		tries--;
+	}
+
+	if (!tries) {
+		DRM_ERROR("Failed to reset decon\n");
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
+static void decon_cmu_enable(struct decon_context *ctx)
+{
+	writel(~DECON_CMU_ALL_CLKGATE_ENABLE, ctx->regs + DECON_CMU);
+}
+
+static void decon_blend_alpha_bits(struct decon_context *ctx)
+{
+	writel(BLENDCON_NEW_8BIT_ALPHA_VALUE, ctx->regs + BLENDCON);
+}
+
+static void decon_set_vidout(struct decon_context *ctx)
+{
+	writel(VIDOUTCON0_LCD_ON | VIDOUTCON0_RGBIF, ctx->regs + VIDOUTCON0);
+}
+
+static void decon_set_crc(struct decon_context *ctx)
+{
+	u32 val = readl(ctx->regs + CRCCTRL);
+
+	writel(val & ~(CRCCTRL_CRCCLKEN | CRCCTRL_CRCEN | CRCCTRL_CRCSTART_F),
+							ctx->regs + CRCCTRL);
+}
+
+static void decon_set_clkval(struct decon_context *ctx)
+{
+	writel(VCLKCON0_CLKVALUP | VCLKCON0_VCLKFREE, ctx->regs + VCLKCON0);
+}
+
+static void decon_set_fixvclk(struct decon_context *ctx)
+{
+	writel(ctx->vidcon1, ctx->regs + VIDCON1(0));
+}
+
+static int decon_poweron(struct exynos_drm_manager *mgr)
+{
+	struct decon_context *ctx = mgr->ctx;
+	int ret;
+
+	if (!ctx->suspended)
+		return 0;
+
+	ctx->suspended = false;
+
+	pm_runtime_get_sync(ctx->dev);
+
+	ret = clk_prepare_enable(ctx->pclk);
+	if (ret < 0) {
+		DRM_ERROR("Failed to prepare_enable the pclk [%d]\n", ret);
+		goto pclk_err;
+	}
+
+	ret = clk_prepare_enable(ctx->aclk);
+	if  (ret < 0) {
+		DRM_ERROR("Failed to prepare_enable the aclk [%d]\n", ret);
+		goto aclk_err;
+	}
+
+	ret = clk_prepare_enable(ctx->eclk);
+	if  (ret < 0) {
+		DRM_ERROR("Failed to prepare_enable the eclk [%d]\n", ret);
+		goto eclk_err;
+	}
+
+	ret = clk_prepare_enable(ctx->vclk);
+	if  (ret < 0) {
+		DRM_ERROR("Failed to prepare_enable the vclk [%d]\n", ret);
+		goto vclk_err;
+	}
+
+	ret = clk_prepare_enable(ctx->dsd);
+	if  (ret < 0) {
+		DRM_ERROR("Failed to prepare_enable the dsd [%d]\n", ret);
+		goto dsd_err;
+	}
+
+	ret = clk_prepare_enable(ctx->lh_disp1);
+	if  (ret < 0) {
+		DRM_ERROR("Failed to prepare_enable the lh_disp1 [%d]\n", ret);
+		goto lh_disp1_err;
+	}
+
+	ret = clk_prepare_enable(ctx->aclk_disp);
+	if  (ret < 0) {
+		DRM_ERROR("Failed to prepare_enable the aclk_disp [%d]\n", ret);
+		goto aclk_disp_err;
+	}
+
+	ret = clk_prepare_enable(ctx->lh_disp0);
+	if  (ret < 0) {
+		DRM_ERROR("Failed to prepare_enable the lh_disp0 [%d]\n", ret);
+		goto lh_disp0_err;
+	}
+
+	ret = decon_reg_reset(mgr->ctx);
+	if  (ret < 0) {
+		DRM_ERROR("Failed to reset decon [%d]\n", ret);
+		goto lh_disp0_err;
+	}
+
+	decon_cmu_enable(mgr->ctx);
+	decon_blend_alpha_bits(mgr->ctx);
+	decon_set_vidout(mgr->ctx);
+	decon_set_crc(mgr->ctx);
+	decon_set_fixvclk(mgr->ctx);
+	decon_set_clkval(mgr->ctx);
+
+	/* if vblank was enabled status, enable it again. */
+	if (test_and_clear_bit(0, &ctx->irq_flags)) {
+		ret = decon_enable_vblank(mgr);
+		if (ret) {
+			DRM_ERROR("Failed to re-enable vblank [%d]\n", ret);
+			goto enable_vblank_err;
+		}
+	}
+
+	decon_window_resume(mgr);
+
+	decon_apply(mgr);
+
+	return 0;
+
+enable_vblank_err:
+	clk_disable_unprepare(ctx->lh_disp0);
+lh_disp0_err:
+	clk_disable_unprepare(ctx->aclk_disp);
+aclk_disp_err:
+	clk_disable_unprepare(ctx->lh_disp1);
+lh_disp1_err:
+	clk_disable_unprepare(ctx->dsd);
+dsd_err:
+	clk_disable_unprepare(ctx->vclk);
+vclk_err:
+	clk_disable_unprepare(ctx->eclk);
+eclk_err:
+	clk_disable_unprepare(ctx->aclk);
+aclk_err:
+	clk_disable_unprepare(ctx->pclk);
+pclk_err:
+	ctx->suspended = true;
+	return ret;
+}
+
+static int decon_poweroff(struct exynos_drm_manager *mgr)
+{
+	struct decon_context *ctx = mgr->ctx;
+
+	if (ctx->suspended)
+		return 0;
+
+	/*
+	 * We need to make sure that all windows are disabled before we
+	 * suspend that connector. Otherwise we might try to scan from
+	 * a destroyed buffer later.
+	 */
+	decon_window_suspend(mgr);
+
+	clk_disable_unprepare(ctx->pclk);
+	clk_disable_unprepare(ctx->aclk);
+	clk_disable_unprepare(ctx->eclk);
+	clk_disable_unprepare(ctx->vclk);
+	clk_disable_unprepare(ctx->dsd);
+	clk_disable_unprepare(ctx->lh_disp1);
+	clk_disable_unprepare(ctx->aclk_disp);
+	clk_disable_unprepare(ctx->lh_disp0);
+
+	pm_runtime_put_sync(ctx->dev);
+
+	ctx->suspended = true;
+	return 0;
+}
+
+static void decon_dpms(struct exynos_drm_manager *mgr, int mode)
+{
+	DRM_DEBUG_KMS("%s, %d\n", __FILE__, mode);
+
+	switch (mode) {
+	case DRM_MODE_DPMS_ON:
+		decon_poweron(mgr);
+		break;
+	case DRM_MODE_DPMS_STANDBY:
+	case DRM_MODE_DPMS_SUSPEND:
+	case DRM_MODE_DPMS_OFF:
+		decon_poweroff(mgr);
+		break;
+	default:
+		DRM_DEBUG_KMS("unspecified mode %d\n", mode);
+		break;
+	}
+}
+
+static struct exynos_drm_manager_ops decon_manager_ops = {
+	.dpms = decon_dpms,
+	.mode_fixup = decon_mode_fixup,
+	.mode_set = decon_mode_set,
+	.commit = decon_commit,
+	.enable_vblank = decon_enable_vblank,
+	.disable_vblank = decon_disable_vblank,
+	.wait_for_vblank = decon_wait_for_vblank,
+	.win_mode_set = decon_win_mode_set,
+	.win_commit = decon_win_commit,
+	.win_disable = decon_win_disable,
+};
+
+static struct exynos_drm_manager decon_manager = {
+	.type = EXYNOS_DISPLAY_TYPE_LCD,
+	.ops = &decon_manager_ops,
+};
+
+static irqreturn_t decon_irq_handler(int irq, void *dev_id)
+{
+	struct decon_context *ctx = (struct decon_context *)dev_id;
+	u32 val;
+
+	val = readl(ctx->regs + VIDINTCON1);
+
+	if (val & VIDINTCON1_INT_FRAME)
+		/* VSYNC interrupt */
+		writel(VIDINTCON1_INT_FRAME, ctx->regs + VIDINTCON1);
+
+	/* check the crtc is detached already from encoder */
+	if (ctx->pipe < 0 || !ctx->drm_dev)
+		goto out;
+
+	drm_handle_vblank(ctx->drm_dev, ctx->pipe);
+	exynos_drm_crtc_finish_pageflip(ctx->drm_dev, ctx->pipe);
+
+	/* set wait vsync event to zero and wake up queue. */
+	if (atomic_read(&ctx->wait_vsync_event)) {
+		atomic_set(&ctx->wait_vsync_event, 0);
+		wake_up(&ctx->wait_vsync_queue);
+	}
+out:
+	return IRQ_HANDLED;
+}
+
+static int decon_bind(struct device *dev, struct device *master, void *data)
+{
+	struct drm_device *drm_dev = data;
+
+	decon_mgr_initialize(&decon_manager, drm_dev);
+	exynos_drm_crtc_create(&decon_manager);
+
+	return 0;
+
+}
+
+static void decon_unbind(struct device *dev, struct device *master,
+			void *data)
+{
+	struct exynos_drm_manager *mgr = dev_get_drvdata(dev);
+
+	decon_dpms(mgr, DRM_MODE_DPMS_OFF);
+	decon_mgr_remove(mgr);
+}
+
+static const struct component_ops decon_component_ops = {
+	.bind	= decon_bind,
+	.unbind = decon_unbind,
+};
+
+static int decon_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct decon_context *ctx;
+	struct resource *res;
+	int ret = -EINVAL;
+
+	ret = exynos_drm_component_add(&pdev->dev, EXYNOS_DEVICE_TYPE_CRTC,
+					decon_manager.type);
+	if (ret)
+		return ret;
+
+	if (!dev->of_node) {
+		ret = -ENODEV;
+		goto err_del_component;
+	}
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx) {
+		ret = -ENOMEM;
+		goto err_del_component;
+	}
+
+	ctx->dev = dev;
+	ctx->suspended = true;
+
+	ctx->pclk = devm_clk_get(dev, "pclk_decon0");
+	if (IS_ERR(ctx->pclk)) {
+		dev_err(dev, "failed to get bus clock\n");
+		ret = PTR_ERR(ctx->pclk);
+		goto err_del_component;
+	}
+
+	ctx->aclk = devm_clk_get(dev, "aclk_decon0");
+	if (IS_ERR(ctx->aclk)) {
+		dev_err(dev, "failed to get aclock\n");
+		ret = PTR_ERR(ctx->aclk);
+		goto err_del_component;
+	}
+
+	ctx->eclk = devm_clk_get(dev, "decon0_eclk");
+	if (IS_ERR(ctx->eclk)) {
+		dev_err(dev, "failed to get eclock\n");
+		ret = PTR_ERR(ctx->eclk);
+		goto err_del_component;
+	}
+
+	ctx->vclk = devm_clk_get(dev, "decon0_vclk");
+	if (IS_ERR(ctx->vclk)) {
+		dev_err(dev, "failed to get vclock\n");
+		ret = PTR_ERR(ctx->vclk);
+		goto err_del_component;
+	}
+
+	ctx->dsd = devm_clk_get(dev, "sclk_dsd");
+	if (IS_ERR(ctx->dsd)) {
+		dev_err(dev, "failed to get dsd clock\n");
+		ret = PTR_ERR(ctx->dsd);
+		goto err_del_component;
+	}
+
+	ctx->lh_disp1 = devm_clk_get(dev, "aclk_lh_disp1");
+	if (IS_ERR(ctx->lh_disp1)) {
+		dev_err(dev, "failed to get lh_disp1 clock\n");
+		ret = PTR_ERR(ctx->lh_disp1);
+		goto err_del_component;
+	}
+
+	ctx->aclk_disp = devm_clk_get(dev, "aclk_disp");
+	if (IS_ERR(ctx->aclk_disp)) {
+		dev_err(dev, "failed to get aclk_disp clock\n");
+		ret = PTR_ERR(ctx->aclk_disp);
+		goto err_del_component;
+	}
+
+	ctx->lh_disp0 = devm_clk_get(dev, "aclk_lh_disp0");
+	if (IS_ERR(ctx->lh_disp0)) {
+		dev_err(dev, "failed to get lh_disp0 clock\n");
+		ret = PTR_ERR(ctx->lh_disp0);
+		goto err_del_component;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	ctx->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(ctx->regs)) {
+		ret = PTR_ERR(ctx->regs);
+		goto err_del_component;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "vsync");
+	if (!res) {
+		dev_err(dev, "irq request failed.\n");
+		ret = -ENXIO;
+		goto err_del_component;
+	}
+
+	ret = devm_request_irq(dev, res->start, decon_irq_handler,
+							0, "drm_decon", ctx);
+	if (ret) {
+		dev_err(dev, "irq request failed.\n");
+		goto err_del_component;
+	}
+
+	init_waitqueue_head(&ctx->wait_vsync_queue);
+	atomic_set(&ctx->wait_vsync_event, 0);
+
+	platform_set_drvdata(pdev, &decon_manager);
+
+	decon_manager.ctx = ctx;
+
+	pm_runtime_enable(&pdev->dev);
+
+	ret = component_add(&pdev->dev, &decon_component_ops);
+	if (ret)
+		goto err_disable_pm_runtime;
+
+	return ret;
+
+err_disable_pm_runtime:
+	pm_runtime_disable(&pdev->dev);
+
+err_del_component:
+	exynos_drm_component_del(&pdev->dev, EXYNOS_DEVICE_TYPE_CRTC);
+	return ret;
+}
+
+static int decon_remove(struct platform_device *pdev)
+{
+	pm_runtime_disable(&pdev->dev);
+
+	component_del(&pdev->dev, &decon_component_ops);
+	exynos_drm_component_del(&pdev->dev, EXYNOS_DEVICE_TYPE_CRTC);
+
+	return 0;
+}
+
+struct platform_driver decon_driver = {
+	.probe		= decon_probe,
+	.remove		= decon_remove,
+	.driver		= {
+		.name	= "exynos-decon",
+		.owner	= THIS_MODULE,
+		.of_match_table = decon_driver_dt_match,
+	},
+};
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
index 443a206..44bdc42 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
@@ -557,10 +557,16 @@ static int exynos_drm_platform_probe(struct platform_device *pdev)
 		return ret;
 #endif
 
+#ifdef CONFIG_DRM_EXYNOS_DECON
+	ret = platform_driver_register(&decon_driver);
+	if (ret < 0)
+		goto err_unregister_fimd_drv;
+#endif
+
 #ifdef CONFIG_DRM_EXYNOS_DP
 	ret = platform_driver_register(&dp_driver);
 	if (ret < 0)
-		goto err_unregister_fimd_drv;
+		goto err_unregister_decon_drv;
 #endif
 
 #ifdef CONFIG_DRM_EXYNOS_DSI
@@ -668,6 +674,11 @@ err_unregister_dp_drv:
 
 #ifdef CONFIG_DRM_EXYNOS_DP
 	platform_driver_unregister(&dp_driver);
+err_unregister_decon_drv:
+#endif
+
+#ifdef CONFIG_DRM_EXYNOS_DECON
+	platform_driver_unregister(&decon_driver);
 err_unregister_fimd_drv:
 #endif
 
@@ -709,6 +720,10 @@ static int exynos_drm_platform_remove(struct platform_device *pdev)
 	platform_driver_unregister(&fimd_driver);
 #endif
 
+#ifdef CONFIG_DRM_EXYNOS_DECON
+	platform_driver_unregister(&decon_driver);
+#endif
+
 #ifdef CONFIG_DRM_EXYNOS_DSI
 	platform_driver_unregister(&dsi_driver);
 #endif
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
index d22e640..25f750d 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
@@ -352,6 +352,16 @@ int exynos_drm_probe_vidi(void);
  */
 void exynos_drm_remove_vidi(void);
 
+/*
+ * this function registers exynos drm decon platform device/driver.
+ */
+int exynos_drm_probe_decon(void);
+
+/*
+ * this function unregister exynos drm decon platform device/driver.
+ */
+void exynos_drm_remove_decon(void);
+
 /* This function creates a encoder and a connector, and initializes them. */
 int exynos_drm_create_enc_conn(struct drm_device *dev,
 				struct exynos_drm_display *display);
@@ -364,6 +374,7 @@ void exynos_drm_component_del(struct device *dev,
 				enum exynos_drm_device_type dev_type);
 
 extern struct platform_driver fimd_driver;
+extern struct platform_driver decon_driver;
 extern struct platform_driver dp_driver;
 extern struct platform_driver dsi_driver;
 extern struct platform_driver mixer_driver;
diff --git a/include/video/samsung_decon.h b/include/video/samsung_decon.h
new file mode 100644
index 0000000..8839120
--- /dev/null
+++ b/include/video/samsung_decon.h
@@ -0,0 +1,346 @@
+/* include/video/exynos_drm_decon.h
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Author: Ajay Kumar <ajaykumar.rs@samsung.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+/* VIDCON0 */
+#define VIDCON0					(0x00)
+
+#define VIDCON0_SWRESET				(1 << 28)
+#define VIDCON0_DECON_STOP_STATUS		(1 << 2)
+#define VIDCON0_ENVID				(1 << 1)
+#define VIDCON0_ENVID_F				(1 << 0)
+
+/* VIDOUTCON0 */
+#define VIDOUTCON0				(0x4)
+
+#define VIDOUTCON0_LCD_ON			(0x1 << 24)
+#define VIDOUTCON0_LCD_OFF			(0x0 << 24)
+#define VIDOUTCON0_IF_SHIFT			(23)
+#define VIDOUTCON0_IF_MASK			(0x1 << 23)
+#define VIDOUTCON0_RGBIF			(0x0 << 23)
+#define VIDOUTCON0_I80IF			(0x1 << 23)
+
+/* VIDCON3 */
+#define VIDCON3					(0x8)
+
+/* VIDCON4 */
+#define VIDCON4					(0xC)
+#define VIDCON4_FIFOCNT_START_EN		(1 << 0)
+
+/* VCLKCON0 */
+#define VCLKCON0				0x10
+#define VCLKCON0_CLKVALUP			(1 << 8)
+#define VCLKCON0_VCLKFREE			(1 << 0)
+
+/* VCLKCON */
+#define VCLKCON1				0x14
+#define VCLKCON1_CLKVAL_NUM_VCLK(val)		(((val) & 0xff) << 0)
+#define VCLKCON2				0x18
+
+/* SHADOWCON */
+#define SHADOWCON				(0x30)
+
+#define SHADOWCON_WINx_PROTECT(_win)		(1 << (10 + (_win)))
+
+/* WINCONx */
+#define WINCON(_win)				(0x50 + ((_win) * 4))
+
+#define WINCONx_BUFSTATUS			(0x3 << 30)
+#define WINCONx_BUFSEL_MASK			(0x3 << 28)
+#define WINCONx_BUFSEL_SHIFT			(28)
+#define WINCONx_TRIPLE_BUF_MODE			(0x1 << 18)
+#define WINCONx_DOUBLE_BUF_MODE			(0x0 << 18)
+#define WINCONx_BURSTLEN_16WORD			(0x0 << 11)
+#define WINCONx_BURSTLEN_8WORD			(0x1 << 11)
+#define WINCONx_BURSTLEN_MASK			(0x1 << 11)
+#define WINCONx_BURSTLEN_SHIFT			(11)
+#define WINCONx_BLD_PLANE			(0 << 8)
+#define WINCONx_BLD_PIX				(1 << 8)
+#define WINCONx_ALPHA_MUL			(1 << 7)
+
+#define WINCONx_BPPMODE_MASK			(0xf << 2)
+#define WINCONx_BPPMODE_SHIFT			(2)
+#define WINCONx_BPPMODE_16BPP_565		(0x8 << 2)
+#define WINCONx_BPPMODE_24BPP_BGRx		(0x7 << 2)
+#define WINCONx_BPPMODE_24BPP_RGBx		(0x6 << 2)
+#define WINCONx_BPPMODE_24BPP_xBGR		(0x5 << 2)
+#define WINCONx_BPPMODE_24BPP_xRGB		(0x4 << 2)
+#define WINCONx_BPPMODE_32BPP_BGRA		(0x3 << 2)
+#define WINCONx_BPPMODE_32BPP_RGBA		(0x2 << 2)
+#define WINCONx_BPPMODE_32BPP_ABGR		(0x1 << 2)
+#define WINCONx_BPPMODE_32BPP_ARGB		(0x0 << 2)
+#define WINCONx_ALPHA_SEL			(1 << 1)
+#define WINCONx_ENWIN				(1 << 0)
+
+#define WINCON1_ALPHA_MUL_F			(1 << 7)
+#define WINCON2_ALPHA_MUL_F			(1 << 7)
+#define WINCON3_ALPHA_MUL_F			(1 << 7)
+#define WINCON4_ALPHA_MUL_F			(1 << 7)
+
+/*  VIDOSDxH: The height for the OSD image(READ ONLY)*/
+#define VIDOSD_H(_x)				(0x80 + ((_x) * 4))
+
+/* Frame buffer start addresses: VIDWxxADD0n */
+#define VIDW_BUF_START(_win)			(0x80 + ((_win) * 0x10))
+#define VIDW_BUF_START1(_win)			(0x84 + ((_win) * 0x10))
+#define VIDW_BUF_START2(_win)			(0x88 + ((_win) * 0x10))
+
+#define VIDW_WHOLE_X(_win)			(0x0130 + ((_win) * 8))
+#define VIDW_WHOLE_Y(_win)			(0x0134 + ((_win) * 8))
+#define VIDW_OFFSET_X(_win)			(0x0170 + ((_win) * 8))
+#define VIDW_OFFSET_Y(_win)			(0x0174 + ((_win) * 8))
+#define VIDW_BLKOFFSET(_win)			(0x01B0 + ((_win) * 4))
+#define VIDW_BLKSIZE(win)			(0x0200 + ((_win) * 4))
+
+/* Interrupt controls register */
+#define VIDINTCON2				(0x228)
+
+#define VIDINTCON1_INTEXTRA1_EN			(1 << 1)
+#define VIDINTCON1_INTEXTRA0_EN			(1 << 0)
+
+/* Interrupt controls and status register */
+#define VIDINTCON3				(0x22C)
+
+#define VIDINTCON1_INTEXTRA1_PEND		(1 << 1)
+#define VIDINTCON1_INTEXTRA0_PEND		(1 << 0)
+
+/* VIDOSDxA ~ VIDOSDxE */
+#define VIDOSD_BASE				(0x230)
+
+#define OSD_STRIDE				(0x20)
+
+#define VIDOSD_A(_win)				(VIDOSD_BASE + \
+						((_win) * OSD_STRIDE) + 0x00)
+#define VIDOSD_B(_win)				(VIDOSD_BASE + \
+						((_win) * OSD_STRIDE) + 0x04)
+#define VIDOSD_C(_win)				(VIDOSD_BASE + \
+						((_win) * OSD_STRIDE) + 0x08)
+#define VIDOSD_D(_win)				(VIDOSD_BASE + \
+						((_win) * OSD_STRIDE) + 0x0C)
+#define VIDOSD_E(_win)				(VIDOSD_BASE + \
+						((_win) * OSD_STRIDE) + 0x10)
+
+#define VIDOSDxA_TOPLEFT_X_MASK			(0x1fff << 13)
+#define VIDOSDxA_TOPLEFT_X_SHIFT		(13)
+#define VIDOSDxA_TOPLEFT_X_LIMIT		(0x1fff)
+#define VIDOSDxA_TOPLEFT_X(_x)			(((_x) & 0x1fff) << 13)
+
+#define VIDOSDxA_TOPLEFT_Y_MASK			(0x1fff << 0)
+#define VIDOSDxA_TOPLEFT_Y_SHIFT		(0)
+#define VIDOSDxA_TOPLEFT_Y_LIMIT		(0x1fff)
+#define VIDOSDxA_TOPLEFT_Y(_x)			(((_x) & 0x1fff) << 0)
+
+#define VIDOSDxB_BOTRIGHT_X_MASK		(0x1fff << 13)
+#define VIDOSDxB_BOTRIGHT_X_SHIFT		(13)
+#define VIDOSDxB_BOTRIGHT_X_LIMIT		(0x1fff)
+#define VIDOSDxB_BOTRIGHT_X(_x)			(((_x) & 0x1fff) << 13)
+
+#define VIDOSDxB_BOTRIGHT_Y_MASK		(0x1fff << 0)
+#define VIDOSDxB_BOTRIGHT_Y_SHIFT		(0)
+#define VIDOSDxB_BOTRIGHT_Y_LIMIT		(0x1fff)
+#define VIDOSDxB_BOTRIGHT_Y(_x)			(((_x) & 0x1fff) << 0)
+
+#define VIDOSDxC_ALPHA0_R_F(_x)			(((_x) & 0xFF) << 16)
+#define VIDOSDxC_ALPHA0_G_F(_x)			(((_x) & 0xFF) << 8)
+#define VIDOSDxC_ALPHA0_B_F(_x)			(((_x) & 0xFF) << 0)
+
+#define VIDOSDxD_ALPHA1_R_F(_x)			(((_x) & 0xFF) << 16)
+#define VIDOSDxD_ALPHA1_G_F(_x)			(((_x) & 0xFF) << 8)
+#define VIDOSDxD_ALPHA1_B_F(_x)			(((_x) & 0xFF) >> 0)
+
+/* Window MAP (Color map) */
+#define WINxMAP(_win)				(0x340 + ((_win) * 4))
+
+#define WINxMAP_MAP				(1 << 24)
+#define WINxMAP_MAP_COLOUR_MASK			(0xffffff << 0)
+#define WINxMAP_MAP_COLOUR_SHIFT		(0)
+#define WINxMAP_MAP_COLOUR_LIMIT		(0xffffff)
+#define WINxMAP_MAP_COLOUR(_x)			((_x) << 0)
+
+/* Window colour-key control registers */
+#define WKEYCON					(0x370)
+
+#define WKEYCON0				(0x00)
+#define WKEYCON1				(0x04)
+#define WxKEYCON0_KEYBL_EN			(1 << 26)
+#define WxKEYCON0_KEYEN_F			(1 << 25)
+#define WxKEYCON0_DIRCON			(1 << 24)
+#define WxKEYCON0_COMPKEY_MASK			(0xffffff << 0)
+#define WxKEYCON0_COMPKEY_SHIFT			(0)
+#define WxKEYCON0_COMPKEY_LIMIT			(0xffffff)
+#define WxKEYCON0_COMPKEY(_x)			((_x) << 0)
+#define WxKEYCON1_COLVAL_MASK			(0xffffff << 0)
+#define WxKEYCON1_COLVAL_SHIFT			(0)
+#define WxKEYCON1_COLVAL_LIMIT			(0xffffff)
+#define WxKEYCON1_COLVAL(_x)			((_x) << 0)
+
+/* color key control register for hardware window 1 ~ 4. */
+#define WKEYCON0_BASE(x)		((WKEYCON + WKEYCON0) + ((x - 1) * 8))
+/* color key value register for hardware window 1 ~ 4. */
+#define WKEYCON1_BASE(x)		((WKEYCON + WKEYCON1) + ((x - 1) * 8))
+
+/* Window KEY Alpha value */
+#define WxKEYALPHA(_win)			(0x3A0 + (((_win) - 1) * 0x4))
+
+#define Wx_KEYALPHA_R_F_SHIFT			(16)
+#define Wx_KEYALPHA_G_F_SHIFT			(8)
+#define Wx_KEYALPHA_B_F_SHIFT			(0)
+
+/* Blending equation */
+#define BLENDE(_win)				(0x03C0 + ((_win) * 4))
+#define BLENDE_COEF_ZERO			0x0
+#define BLENDE_COEF_ONE				0x1
+#define BLENDE_COEF_ALPHA_A			0x2
+#define BLENDE_COEF_ONE_MINUS_ALPHA_A		0x3
+#define BLENDE_COEF_ALPHA_B			0x4
+#define BLENDE_COEF_ONE_MINUS_ALPHA_B		0x5
+#define BLENDE_COEF_ALPHA0			0x6
+#define BLENDE_COEF_A				0xA
+#define BLENDE_COEF_ONE_MINUS_A			0xB
+#define BLENDE_COEF_B				0xC
+#define BLENDE_COEF_ONE_MINUS_B			0xD
+#define BLENDE_Q_FUNC(_v)			((_v) << 18)
+#define BLENDE_P_FUNC(_v)			((_v) << 12)
+#define BLENDE_B_FUNC(_v)			((_v) << 6)
+#define BLENDE_A_FUNC(_v)			((_v) << 0)
+
+/* Blending equation control */
+#define BLENDCON				(0x3D8)
+#define BLENDCON_NEW_MASK			(1 << 0)
+#define BLENDCON_NEW_8BIT_ALPHA_VALUE		(1 << 0)
+#define BLENDCON_NEW_4BIT_ALPHA_VALUE		(0 << 0)
+
+/* Interrupt control register */
+#define VIDINTCON0				(0x500)
+
+#define VIDINTCON0_WAKEUP_MASK			(0x3f << 26)
+#define VIDINTCON0_INTEXTRAEN			(1 << 21)
+
+#define VIDINTCON0_FRAMESEL0_SHIFT		(15)
+#define VIDINTCON0_FRAMESEL0_MASK		(0x3 << 15)
+#define VIDINTCON0_FRAMESEL0_BACKPORCH		(0x0 << 15)
+#define VIDINTCON0_FRAMESEL0_VSYNC		(0x1 << 15)
+#define VIDINTCON0_FRAMESEL0_ACTIVE		(0x2 << 15)
+#define VIDINTCON0_FRAMESEL0_FRONTPORCH		(0x3 << 15)
+
+#define VIDINTCON0_INT_FRAME			(1 << 11)
+
+#define VIDINTCON0_FIFOLEVEL_MASK		(0x7 << 3)
+#define VIDINTCON0_FIFOLEVEL_SHIFT		(3)
+#define VIDINTCON0_FIFOLEVEL_EMPTY		(0x0 << 3)
+#define VIDINTCON0_FIFOLEVEL_TO25PC		(0x1 << 3)
+#define VIDINTCON0_FIFOLEVEL_TO50PC		(0x2 << 3)
+#define VIDINTCON0_FIFOLEVEL_FULL		(0x4 << 3)
+
+#define VIDINTCON0_FIFOSEL_MAIN_EN		(1 << 1)
+#define VIDINTCON0_INT_FIFO			(1 << 1)
+
+#define VIDINTCON0_INT_ENABLE			(1 << 0)
+
+/* Interrupt controls and status register */
+#define VIDINTCON1				(0x504)
+
+#define VIDINTCON1_INT_EXTRA			(1 << 3)
+#define VIDINTCON1_INT_I80			(1 << 2)
+#define VIDINTCON1_INT_FRAME			(1 << 1)
+#define VIDINTCON1_INT_FIFO			(1 << 0)
+
+/* VIDCON1 */
+#define VIDCON1(_x)				(0x0600 + ((_x) * 0x50))
+#define VIDCON1_LINECNT_GET(_v)			(((_v) >> 17) & 0x1fff)
+#define VIDCON1_VCLK_MASK			(0x3 << 9)
+#define VIDCON1_VCLK_HOLD			(0x0 << 9)
+#define VIDCON1_VCLK_RUN			(0x1 << 9)
+#define VIDCON1_VCLK_RUN_VDEN_DISABLE		(0x3 << 9)
+#define VIDCON1_RGB_ORDER_O_MASK		(0x7 << 4)
+#define VIDCON1_RGB_ORDER_O_RGB			(0x0 << 4)
+#define VIDCON1_RGB_ORDER_O_GBR			(0x1 << 4)
+#define VIDCON1_RGB_ORDER_O_BRG			(0x2 << 4)
+#define VIDCON1_RGB_ORDER_O_BGR			(0x4 << 4)
+#define VIDCON1_RGB_ORDER_O_RBG			(0x5 << 4)
+#define VIDCON1_RGB_ORDER_O_GRB			(0x6 << 4)
+
+/* VIDTCON0 */
+#define VIDTCON0				(0x610)
+
+#define VIDTCON0_VBPD_MASK			(0xffff << 16)
+#define VIDTCON0_VBPD_SHIFT			(16)
+#define VIDTCON0_VBPD_LIMIT			(0xffff)
+#define VIDTCON0_VBPD(_x)			((_x) << 16)
+
+#define VIDTCON0_VFPD_MASK			(0xffff << 0)
+#define VIDTCON0_VFPD_SHIFT			(0)
+#define VIDTCON0_VFPD_LIMIT			(0xffff)
+#define VIDTCON0_VFPD(_x)			((_x) << 0)
+
+/* VIDTCON1 */
+#define VIDTCON1				(0x614)
+
+#define VIDTCON1_VSPW_MASK			(0xffff << 16)
+#define VIDTCON1_VSPW_SHIFT			(16)
+#define VIDTCON1_VSPW_LIMIT			(0xffff)
+#define VIDTCON1_VSPW(_x)			((_x) << 16)
+
+/* VIDTCON2 */
+#define VIDTCON2				(0x618)
+
+#define VIDTCON2_HBPD_MASK			(0xffff << 16)
+#define VIDTCON2_HBPD_SHIFT			(16)
+#define VIDTCON2_HBPD_LIMIT			(0xffff)
+#define VIDTCON2_HBPD(_x)			((_x) << 16)
+
+#define VIDTCON2_HFPD_MASK			(0xffff << 0)
+#define VIDTCON2_HFPD_SHIFT			(0)
+#define VIDTCON2_HFPD_LIMIT			(0xffff)
+#define VIDTCON2_HFPD(_x)			((_x) << 0)
+
+/* VIDTCON3 */
+#define VIDTCON3				(0x61C)
+
+#define VIDTCON3_HSPW_MASK			(0xffff << 16)
+#define VIDTCON3_HSPW_SHIFT			(16)
+#define VIDTCON3_HSPW_LIMIT			(0xffff)
+#define VIDTCON3_HSPW(_x)			((_x) << 16)
+
+/* VIDTCON4 */
+#define VIDTCON4				(0x620)
+
+#define VIDTCON4_LINEVAL_MASK			(0xfff << 16)
+#define VIDTCON4_LINEVAL_SHIFT			(16)
+#define VIDTCON4_LINEVAL_LIMIT			(0xfff)
+#define VIDTCON4_LINEVAL(_x)			(((_x) & 0xfff) << 16)
+
+#define VIDTCON4_HOZVAL_MASK			(0xfff << 0)
+#define VIDTCON4_HOZVAL_SHIFT			(0)
+#define VIDTCON4_HOZVAL_LIMIT			(0xfff)
+#define VIDTCON4_HOZVAL(_x)			(((_x) & 0xfff) << 0)
+
+/* LINECNT OP THRSHOLD*/
+#define LINECNT_OP_THRESHOLD			(0x630)
+
+/* CRCCTRL */
+#define CRCCTRL					(0x6C8)
+#define CRCCTRL_CRCCLKEN			(0x1 << 2)
+#define CRCCTRL_CRCSTART_F			(0x1 << 1)
+#define CRCCTRL_CRCEN				(0x1 << 0)
+
+/* DECON_CMU */
+#define DECON_CMU				(0x704)
+
+#define DECON_CMU_ALL_CLKGATE_ENABLE		(0x3)
+#define DECON_CMU_SE_CLKGATE_ENABLE		(0x1 << 2)
+#define DECON_CMU_SFR_CLKGATE_ENABLE		(0x1 << 1)
+#define DECON_CMU_MEM_CLKGATE_ENABLE		(0x1 << 0)
+
+/* DECON_UPDATE */
+#define DECON_UPDATE				(0x710)
+
+#define DECON_UPDATE_SLAVE_SYNC			(1 << 4)
+#define DECON_UPDATE_STANDALONE_F		(1 << 0)
-- 
1.7.9.5