DRM: add DRM Driver for Samsung SoC EXYNOS4210.

This patch is a DRM Driver for Samsung SoC Exynos4210 and now enables
only FIMD yet but we will add HDMI support also in the future.

this patch is based on git repository below:
git://people.freedesktop.org/~airlied/linux.git
branch name: drm-next
commit-id: 88ef4e3f4f616462b78a7838eb3ffc3818d30f67

you can refer to our working repository below:
http://git.infradead.org/users/kmpark/linux-2.6-samsung
branch name: samsung-drm

We tried to re-use lowlevel codes of the FIMD driver(s3c-fb.c
based on Linux framebuffer) but couldn't so because lowlevel codes
of s3c-fb.c are included internally and so FIMD module of this driver has
its own lowlevel codes.

We used GEM framework for buffer management and DMA APIs(dma_alloc_*)
for buffer allocation so we can allocate physically continuous memory
for DMA through it and also we could use CMA later if CMA is applied to
mainline.

Refer to this link for CMA(Continuous Memory Allocator):
http://lkml.org/lkml/2011/7/20/45

this driver supports only physically continuous memory(non-iommu).

Links to previous versions of the patchset:
v1: < https://lwn.net/Articles/454380/ >
v2: < http://www.spinics.net/lists/kernel/msg1224275.html >
v3: < http://www.spinics.net/lists/dri-devel/msg13755.html >
v4: < http://permalink.gmane.org/gmane.comp.video.dri.devel/60439 >
v5: < http://comments.gmane.org/gmane.comp.video.dri.devel/60802 >

Changelog v2:
DRM: add DRM_IOCTL_SAMSUNG_GEM_MMAP ioctl command.

    this feature maps user address space to physical memory region
    once user application requests DRM_IOCTL_SAMSUNG_GEM_MMAP ioctl.

DRM: code clean and add exception codes.

Changelog v3:
DRM: Support multiple irq.

    FIMD and HDMI have their own irq handler but DRM Framework can regiter
    only one irq handler this patch supports mutiple irq for Samsung SoC.

DRM: Consider modularization.

    each DRM, FIMD could be built as a module.

DRM: Have indenpendent crtc object.

    crtc isn't specific to SoC Platform so this patch gets a crtc
    to be used as common object.
    created crtc could be attached to any encoder object.

DRM: code clean and add exception codes.

Changelog v4:
DRM: remove is_defult from samsung_fb.

    is_default isn't used for default framebuffer.

DRM: code refactoring to fimd module.
    this patch is be considered with multiple display objects and
    would use its own request_irq() to register a irq handler instead of
    drm framework's one.

DRM: remove find_samsung_drm_gem_object()

DRM: move kernel private data structures and definitions to driver folder.

    samsung_drm.h would contain only public information for userspace
    ioctl interface.

DRM: code refactoring to gem modules.
    buffer module isn't dependent of gem module anymore.

DRM: fixed security issue.

DRM: remove encoder porinter from specific connector.

    samsung connector doesn't need to have generic encoder.

DRM: code clean and add exception codes.

Changelog v5:
DRM: updated fimd(display controller) driver.
    added various pixel formats, color key and pixel blending features.

DRM: removed end_buf_off from samsung_drm_overlay structure.
    this variable isn't used and end buffer address would be
    calculated by each sub driver.

DRM: use generic function for mmap_offset.
    replaced samsung_drm_gem_create_mmap_offset() and
    samsung_drm_free_mmap_offset() with generic ones applied
    to mainline recentrly.

DRM: removed unnecessary codes and added exception codes.

DRM: added comments and code clean.

Changelog v6:
DRM: added default config options.

DRM: added padding for 64-bit align.

DRM: changed prefix 'samsung' to 'exynos'

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 796 insertions, 0 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
new file mode 100644
index 00000000000..620ad2d5136
--- /dev/null
+++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
@@ -0,0 +1,796 @@
+/* exynos_drm_fimd.c
+ *
+ * Copyright (C) 2011 Samsung Electronics Co.Ltd
+ * Authors:
+ *	Joonyoung Shim <jy0922.shim@samsung.com>
+ *	Inki Dae <inki.dae@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 "drmP.h"
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#include <drm/exynos_drm.h>
+#include <plat/regs-fb-v4.h>
+
+#include "exynos_drm_drv.h"
+#include "exynos_drm_fbdev.h"
+#include "exynos_drm_crtc.h"
+
+/*
+ * FIMD is stand for Fully Interactive Mobile Display and
+ * as a display controller, it transfers contents drawn on memory
+ * to a LCD Panel through Display Interfaces such as RGB or
+ * CPU Interface.
+ */
+
+/* position control register for hardware window 0, 2 ~ 4.*/
+#define VIDOSD_A(win)		(VIDOSD_BASE + 0x00 + (win) * 16)
+#define VIDOSD_B(win)		(VIDOSD_BASE + 0x04 + (win) * 16)
+/* size control register for hardware window 0. */
+#define VIDOSD_C_SIZE_W0	(VIDOSD_BASE + 0x08)
+/* alpha control register for hardware window 1 ~ 4. */
+#define VIDOSD_C(win)		(VIDOSD_BASE + 0x18 + (win) * 16)
+/* size control register for hardware window 1 ~ 4. */
+#define VIDOSD_D(win)		(VIDOSD_BASE + 0x0C + (win) * 16)
+
+#define VIDWx_BUF_START(win, buf)	(VIDW_BUF_START(buf) + (win) * 8)
+#define VIDWx_BUF_END(win, buf)		(VIDW_BUF_END(buf) + (win) * 8)
+#define VIDWx_BUF_SIZE(win, buf)	(VIDW_BUF_SIZE(buf) + (win) * 4)
+
+/* color key control register for hardware window 1 ~ 4. */
+#define WKEYCON0_BASE(x)		((WKEYCON0 + 0x140) + (x * 8))
+/* color key value register for hardware window 1 ~ 4. */
+#define WKEYCON1_BASE(x)		((WKEYCON1 + 0x140) + (x * 8))
+
+/* FIMD has totally five hardware windows. */
+#define WINDOWS_NR	5
+
+#define get_fimd_context(dev)	platform_get_drvdata(to_platform_device(dev))
+
+struct fimd_win_data {
+	unsigned int		offset_x;
+	unsigned int		offset_y;
+	unsigned int		width;
+	unsigned int		height;
+	unsigned int		bpp;
+	dma_addr_t		paddr;
+	void __iomem		*vaddr;
+	unsigned int		buf_offsize;
+	unsigned int		line_size;	/* bytes */
+};
+
+struct fimd_context {
+	struct exynos_drm_subdrv	subdrv;
+	int				irq;
+	struct drm_crtc			*crtc;
+	struct clk			*bus_clk;
+	struct clk			*lcd_clk;
+	struct resource			*regs_res;
+	void __iomem			*regs;
+	struct fimd_win_data		win_data[WINDOWS_NR];
+	unsigned int			clkdiv;
+	unsigned int			default_win;
+	unsigned long			irq_flags;
+	u32				vidcon0;
+	u32				vidcon1;
+
+	struct fb_videomode		*timing;
+};
+
+static bool fimd_display_is_connected(struct device *dev)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	/* TODO. */
+
+	return true;
+}
+
+static void *fimd_get_timing(struct device *dev)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	return ctx->timing;
+}
+
+static int fimd_check_timing(struct device *dev, void *timing)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	/* TODO. */
+
+	return 0;
+}
+
+static int fimd_display_power_on(struct device *dev, int mode)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	/* TODO. */
+
+	return 0;
+}
+
+static struct exynos_drm_display fimd_display = {
+	.type = EXYNOS_DISPLAY_TYPE_LCD,
+	.is_connected = fimd_display_is_connected,
+	.get_timing = fimd_get_timing,
+	.check_timing = fimd_check_timing,
+	.power_on = fimd_display_power_on,
+};
+
+static void fimd_commit(struct device *dev)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+	struct fb_videomode *timing = ctx->timing;
+	u32 val;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	/* setup polarity values from machine code. */
+	writel(ctx->vidcon1, ctx->regs + VIDCON1);
+
+	/* setup vertical timing values. */
+	val = VIDTCON0_VBPD(timing->upper_margin - 1) |
+	       VIDTCON0_VFPD(timing->lower_margin - 1) |
+	       VIDTCON0_VSPW(timing->vsync_len - 1);
+	writel(val, ctx->regs + VIDTCON0);
+
+	/* setup horizontal timing values.  */
+	val = VIDTCON1_HBPD(timing->left_margin - 1) |
+	       VIDTCON1_HFPD(timing->right_margin - 1) |
+	       VIDTCON1_HSPW(timing->hsync_len - 1);
+	writel(val, ctx->regs + VIDTCON1);
+
+	/* setup horizontal and vertical display size. */
+	val = VIDTCON2_LINEVAL(timing->yres - 1) |
+	       VIDTCON2_HOZVAL(timing->xres - 1);
+	writel(val, ctx->regs + VIDTCON2);
+
+	/* setup clock source, clock divider, enable dma. */
+	val = ctx->vidcon0;
+	val &= ~(VIDCON0_CLKVAL_F_MASK | VIDCON0_CLKDIR);
+
+	if (ctx->clkdiv > 1)
+		val |= VIDCON0_CLKVAL_F(ctx->clkdiv - 1) | VIDCON0_CLKDIR;
+	else
+		val &= ~VIDCON0_CLKDIR;	/* 1:1 clock */
+
+	/*
+	 * 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);
+}
+
+static int fimd_enable_vblank(struct device *dev)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+	u32 val;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	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;
+		val &= ~VIDINTCON0_FRAMESEL1_MASK;
+		val |= VIDINTCON0_FRAMESEL1_NONE;
+
+		writel(val, ctx->regs + VIDINTCON0);
+	}
+
+	return 0;
+}
+
+static void fimd_disable_vblank(struct device *dev)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+	u32 val;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	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 struct exynos_drm_manager_ops fimd_manager_ops = {
+	.commit = fimd_commit,
+	.enable_vblank = fimd_enable_vblank,
+	.disable_vblank = fimd_disable_vblank,
+};
+
+static void fimd_win_mode_set(struct device *dev,
+			      struct exynos_drm_overlay *overlay)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+	struct fimd_win_data *win_data;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	if (!overlay) {
+		dev_err(dev, "overlay is NULL\n");
+		return;
+	}
+
+	win_data = &ctx->win_data[ctx->default_win];
+
+	win_data->offset_x = overlay->offset_x;
+	win_data->offset_y = overlay->offset_y;
+	win_data->width = overlay->width;
+	win_data->height = overlay->height;
+	win_data->paddr = overlay->paddr;
+	win_data->vaddr = overlay->vaddr;
+	win_data->bpp = overlay->bpp;
+	win_data->buf_offsize = overlay->buf_offsize * (overlay->bpp >> 3);
+	win_data->line_size = overlay->line_size * (overlay->bpp >> 3);
+}
+
+static void fimd_win_set_pixfmt(struct device *dev, unsigned int win)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+	struct fimd_win_data *win_data = &ctx->win_data[win];
+	unsigned long val;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	val = WINCONx_ENWIN;
+
+	switch (win_data->bpp) {
+	case 1:
+		val |= WINCON0_BPPMODE_1BPP;
+		val |= WINCONx_BITSWP;
+		val |= WINCONx_BURSTLEN_4WORD;
+		break;
+	case 2:
+		val |= WINCON0_BPPMODE_2BPP;
+		val |= WINCONx_BITSWP;
+		val |= WINCONx_BURSTLEN_8WORD;
+		break;
+	case 4:
+		val |= WINCON0_BPPMODE_4BPP;
+		val |= WINCONx_BITSWP;
+		val |= WINCONx_BURSTLEN_8WORD;
+		break;
+	case 8:
+		val |= WINCON0_BPPMODE_8BPP_PALETTE;
+		val |= WINCONx_BURSTLEN_8WORD;
+		val |= WINCONx_BYTSWP;
+		break;
+	case 16:
+		val |= WINCON0_BPPMODE_16BPP_565;
+		val |= WINCONx_HAWSWP;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	case 24:
+		val |= WINCON0_BPPMODE_24BPP_888;
+		val |= WINCONx_WSWP;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	case 32:
+		val |= WINCON1_BPPMODE_28BPP_A4888
+			| WINCON1_BLD_PIX | WINCON1_ALPHA_SEL;
+		val |= WINCONx_WSWP;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	default:
+		DRM_DEBUG_KMS("invalid pixel size so using unpacked 24bpp.\n");
+
+		val |= WINCON0_BPPMODE_24BPP_888;
+		val |= WINCONx_WSWP;
+		val |= WINCONx_BURSTLEN_16WORD;
+		break;
+	}
+
+	DRM_DEBUG_KMS("bpp = %d\n", win_data->bpp);
+
+	writel(val, ctx->regs + WINCON(win));
+}
+
+static void fimd_win_set_colkey(struct device *dev, unsigned int win)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+	unsigned int keycon0 = 0, keycon1 = 0;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	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));
+}
+
+static void fimd_win_commit(struct device *dev)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+	struct fimd_win_data *win_data;
+	int win = ctx->default_win;
+	unsigned long val, alpha, size;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	if (win < 0 || win > WINDOWS_NR)
+		return;
+
+	win_data = &ctx->win_data[win];
+
+	/*
+	 * SHADOWCON register is used for enabling timing.
+	 *
+	 * for example, once only width value of a register is set,
+	 * if the dma is started then fimd 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 */
+	val = readl(ctx->regs + SHADOWCON);
+	val |= SHADOWCON_WINx_PROTECT(win);
+	writel(val, ctx->regs + SHADOWCON);
+
+	/* buffer start address */
+	val = win_data->paddr;
+	writel(val, ctx->regs + VIDWx_BUF_START(win, 0));
+
+	/* buffer end address */
+	size = win_data->width * win_data->height * (win_data->bpp >> 3);
+	val = win_data->paddr + size;
+	writel(val, ctx->regs + VIDWx_BUF_END(win, 0));
+
+	DRM_DEBUG_KMS("start addr = 0x%lx, end addr = 0x%lx, size = 0x%lx\n",
+			(unsigned long)win_data->paddr, val, size);
+
+	/* buffer size */
+	val = VIDW_BUF_SIZE_OFFSET(win_data->buf_offsize) |
+		VIDW_BUF_SIZE_PAGEWIDTH(win_data->line_size);
+	writel(val, ctx->regs + VIDWx_BUF_SIZE(win, 0));
+
+	/* OSD position */
+	val = VIDOSDxA_TOPLEFT_X(win_data->offset_x) |
+		VIDOSDxA_TOPLEFT_Y(win_data->offset_y);
+	writel(val, ctx->regs + VIDOSD_A(win));
+
+	val = VIDOSDxB_BOTRIGHT_X(win_data->offset_x + win_data->width - 1) |
+		VIDOSDxB_BOTRIGHT_Y(win_data->offset_y + win_data->height - 1);
+	writel(val, ctx->regs + VIDOSD_B(win));
+
+	DRM_DEBUG_KMS("osd pos: tx = %d, ty = %d, bx = %d, by = %x\n",
+			win_data->offset_x, win_data->offset_y,
+			win_data->offset_x + win_data->width - 1,
+			win_data->offset_y + win_data->height - 1);
+
+	/* hardware window 0 doesn't support alpha channel. */
+	if (win != 0) {
+		/* OSD alpha */
+		alpha = VIDISD14C_ALPHA1_R(0xf) |
+			VIDISD14C_ALPHA1_G(0xf) |
+			VIDISD14C_ALPHA1_B(0xf);
+
+		writel(alpha, ctx->regs + VIDOSD_C(win));
+	}
+
+	/* OSD size */
+	if (win != 3 && win != 4) {
+		u32 offset = VIDOSD_D(win);
+		if (win == 0)
+			offset = VIDOSD_C_SIZE_W0;
+		val = win_data->width * win_data->height;
+		writel(val, ctx->regs + offset);
+
+		DRM_DEBUG_KMS("osd size = 0x%x\n", (unsigned int)val);
+	}
+
+	fimd_win_set_pixfmt(dev, win);
+
+	/* hardware window 0 doesn't support color key. */
+	if (win != 0)
+		fimd_win_set_colkey(dev, win);
+
+	/* Enable DMA channel and unprotect windows */
+	val = readl(ctx->regs + SHADOWCON);
+	val |= SHADOWCON_CHx_ENABLE(win);
+	val &= ~SHADOWCON_WINx_PROTECT(win);
+	writel(val, ctx->regs + SHADOWCON);
+}
+
+static void fimd_win_disable(struct device *dev)
+{
+	struct fimd_context *ctx = get_fimd_context(dev);
+	struct fimd_win_data *win_data;
+	int win = ctx->default_win;
+	u32 val;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	if (win < 0 || win > WINDOWS_NR)
+		return;
+
+	win_data = &ctx->win_data[win];
+
+	/* protect windows */
+	val = readl(ctx->regs + SHADOWCON);
+	val |= SHADOWCON_WINx_PROTECT(win);
+	writel(val, ctx->regs + SHADOWCON);
+
+	/* wincon */
+	val = readl(ctx->regs + WINCON(win));
+	val &= ~WINCONx_ENWIN;
+	writel(val, ctx->regs + WINCON(win));
+
+	/* unprotect windows */
+	val = readl(ctx->regs + SHADOWCON);
+	val &= ~SHADOWCON_CHx_ENABLE(win);
+	val &= ~SHADOWCON_WINx_PROTECT(win);
+	writel(val, ctx->regs + SHADOWCON);
+}
+
+static struct exynos_drm_overlay_ops fimd_overlay_ops = {
+	.mode_set = fimd_win_mode_set,
+	.commit = fimd_win_commit,
+	.disable = fimd_win_disable,
+};
+
+/* for pageflip event */
+static void fimd_finish_pageflip(struct drm_device *drm_dev, int crtc)
+{
+	struct exynos_drm_private *dev_priv = drm_dev->dev_private;
+	struct drm_pending_vblank_event *e, *t;
+	struct timeval now;
+	unsigned long flags;
+
+	if (!dev_priv->pageflip_event)
+		return;
+
+	spin_lock_irqsave(&drm_dev->event_lock, flags);
+
+	exynos_drm_crtc_apply(dev_priv->crtc[crtc]);
+
+	list_for_each_entry_safe(e, t, &dev_priv->pageflip_event_list,
+			base.link) {
+		do_gettimeofday(&now);
+		e->event.sequence = 0;
+		e->event.tv_sec = now.tv_sec;
+		e->event.tv_usec = now.tv_usec;
+
+		list_move_tail(&e->base.link, &e->base.file_priv->event_list);
+		wake_up_interruptible(&e->base.file_priv->event_wait);
+	}
+
+	drm_vblank_put(drm_dev, crtc);
+	dev_priv->pageflip_event = false;
+
+	spin_unlock_irqrestore(&drm_dev->event_lock, flags);
+}
+
+static irqreturn_t fimd_irq_handler(int irq, void *dev_id)
+{
+	struct fimd_context *ctx = (struct fimd_context *)dev_id;
+	struct exynos_drm_subdrv *subdrv = &ctx->subdrv;
+	struct drm_device *drm_dev = subdrv->drm_dev;
+	struct device *dev = subdrv->manager.dev;
+	struct exynos_drm_manager *manager = &subdrv->manager;
+	u32 val;
+
+	val = readl(ctx->regs + VIDINTCON1);
+
+	if (val & VIDINTCON1_INT_FRAME)
+		/* VSYNC interrupt */
+		writel(VIDINTCON1_INT_FRAME, ctx->regs + VIDINTCON1);
+
+	drm_handle_vblank(drm_dev, manager->pipe);
+	fimd_finish_pageflip(drm_dev, manager->pipe);
+
+	return IRQ_HANDLED;
+}
+
+static int fimd_subdrv_probe(struct drm_device *drm_dev)
+{
+	struct drm_driver *drm_driver = drm_dev->driver;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	/*
+	 * enable drm irq mode.
+	 * - with irq_enabled = 1, we can use the vblank feature.
+	 *
+	 * P.S. note that we wouldn't use drm irq handler but
+	 *	just specific driver own one instead because
+	 *	drm framework supports only one irq handler.
+	 */
+	drm_dev->irq_enabled = 1;
+
+	/*
+	 * with vblank_disable_allowed = 1, vblank interrupt will be disabled
+	 * by drm timer once a current process gives up ownership of
+	 * vblank event.(drm_vblank_put function was called)
+	 */
+	drm_dev->vblank_disable_allowed = 1;
+
+	return 0;
+}
+
+static void fimd_subdrv_remove(struct drm_device *drm_dev)
+{
+	struct drm_driver *drm_driver = drm_dev->driver;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	/* TODO. */
+}
+
+static int fimd_calc_clkdiv(struct fimd_context *ctx,
+			    struct fb_videomode *timing)
+{
+	unsigned long clk = clk_get_rate(ctx->lcd_clk);
+	u32 retrace;
+	u32 clkdiv;
+	u32 best_framerate = 0;
+	u32 framerate;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	retrace = timing->left_margin + timing->hsync_len +
+				timing->right_margin + timing->xres;
+	retrace *= timing->upper_margin + timing->vsync_len +
+				timing->lower_margin + timing->yres;
+
+	/* default framerate is 60Hz */
+	if (!timing->refresh)
+		timing->refresh = 60;
+
+	clk /= retrace;
+
+	for (clkdiv = 1; clkdiv < 0x100; clkdiv++) {
+		int tmp;
+
+		/* get best framerate */
+		framerate = clk / clkdiv;
+		tmp = timing->refresh - framerate;
+		if (tmp < 0) {
+			best_framerate = framerate;
+			continue;
+		} else {
+			if (!best_framerate)
+				best_framerate = framerate;
+			else if (tmp < (best_framerate - framerate))
+				best_framerate = framerate;
+			break;
+		}
+	}
+
+	return clkdiv;
+}
+
+static void fimd_clear_win(struct fimd_context *ctx, int win)
+{
+	u32 val;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	writel(0, ctx->regs + WINCON(win));
+	writel(0, ctx->regs + VIDOSD_A(win));
+	writel(0, ctx->regs + VIDOSD_B(win));
+	writel(0, ctx->regs + VIDOSD_C(win));
+
+	if (win == 1 || win == 2)
+		writel(0, ctx->regs + VIDOSD_D(win));
+
+	val = readl(ctx->regs + SHADOWCON);
+	val &= ~SHADOWCON_WINx_PROTECT(win);
+	writel(val, ctx->regs + SHADOWCON);
+}
+
+static int __devinit fimd_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct fimd_context *ctx;
+	struct exynos_drm_subdrv *subdrv;
+	struct exynos_drm_fimd_pdata *pdata;
+	struct fb_videomode *timing;
+	struct resource *res;
+	int win;
+	int ret = -EINVAL;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	pdata = pdev->dev.platform_data;
+	if (!pdata) {
+		dev_err(dev, "no platform data specified\n");
+		return -EINVAL;
+	}
+
+	timing = &pdata->timing;
+	if (!timing) {
+		dev_err(dev, "timing is null.\n");
+		return -EINVAL;
+	}
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->bus_clk = clk_get(dev, "fimd");
+	if (IS_ERR(ctx->bus_clk)) {
+		dev_err(dev, "failed to get bus clock\n");
+		ret = PTR_ERR(ctx->bus_clk);
+		goto err_clk_get;
+	}
+
+	clk_enable(ctx->bus_clk);
+
+	ctx->lcd_clk = clk_get(dev, "sclk_fimd");
+	if (IS_ERR(ctx->lcd_clk)) {
+		dev_err(dev, "failed to get lcd clock\n");
+		ret = PTR_ERR(ctx->lcd_clk);
+		goto err_bus_clk;
+	}
+
+	clk_enable(ctx->lcd_clk);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "failed to find registers\n");
+		ret = -ENOENT;
+		goto err_clk;
+	}
+
+	ctx->regs_res = request_mem_region(res->start, resource_size(res),
+					   dev_name(dev));
+	if (!ctx->regs_res) {
+		dev_err(dev, "failed to claim register region\n");
+		ret = -ENOENT;
+		goto err_clk;
+	}
+
+	ctx->regs = ioremap(res->start, resource_size(res));
+	if (!ctx->regs) {
+		dev_err(dev, "failed to map registers\n");
+		ret = -ENXIO;
+		goto err_req_region_io;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(dev, "irq request failed.\n");
+		goto err_req_region_irq;
+	}
+
+	ctx->irq = res->start;
+
+	for (win = 0; win < WINDOWS_NR; win++)
+		fimd_clear_win(ctx, win);
+
+	ret = request_irq(ctx->irq, fimd_irq_handler, 0, "drm_fimd", ctx);
+	if (ret < 0) {
+		dev_err(dev, "irq request failed.\n");
+		goto err_req_irq;
+	}
+
+	ctx->clkdiv = fimd_calc_clkdiv(ctx, timing);
+	ctx->vidcon0 = pdata->vidcon0;
+	ctx->vidcon1 = pdata->vidcon1;
+	ctx->default_win = pdata->default_win;
+	ctx->timing = timing;
+
+	timing->pixclock = clk_get_rate(ctx->lcd_clk) / ctx->clkdiv;
+
+	DRM_DEBUG_KMS("pixel clock = %d, clkdiv = %d\n",
+			timing->pixclock, ctx->clkdiv);
+
+	subdrv = &ctx->subdrv;
+
+	subdrv->probe = fimd_subdrv_probe;
+	subdrv->remove = fimd_subdrv_remove;
+	subdrv->manager.pipe = -1;
+	subdrv->manager.ops = &fimd_manager_ops;
+	subdrv->manager.overlay_ops = &fimd_overlay_ops;
+	subdrv->manager.display = &fimd_display;
+	subdrv->manager.dev = dev;
+
+	platform_set_drvdata(pdev, ctx);
+	exynos_drm_subdrv_register(subdrv);
+
+	return 0;
+
+err_req_irq:
+err_req_region_irq:
+	iounmap(ctx->regs);
+
+err_req_region_io:
+	release_resource(ctx->regs_res);
+	kfree(ctx->regs_res);
+
+err_clk:
+	clk_disable(ctx->lcd_clk);
+	clk_put(ctx->lcd_clk);
+
+err_bus_clk:
+	clk_disable(ctx->bus_clk);
+	clk_put(ctx->bus_clk);
+
+err_clk_get:
+	kfree(ctx);
+	return ret;
+}
+
+static int __devexit fimd_remove(struct platform_device *pdev)
+{
+	struct fimd_context *ctx = platform_get_drvdata(pdev);
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	exynos_drm_subdrv_unregister(&ctx->subdrv);
+
+	clk_disable(ctx->lcd_clk);
+	clk_disable(ctx->bus_clk);
+	clk_put(ctx->lcd_clk);
+	clk_put(ctx->bus_clk);
+
+	iounmap(ctx->regs);
+	release_resource(ctx->regs_res);
+	kfree(ctx->regs_res);
+	free_irq(ctx->irq, ctx);
+
+	kfree(ctx);
+
+	return 0;
+}
+
+static struct platform_driver fimd_driver = {
+	.probe		= fimd_probe,
+	.remove		= __devexit_p(fimd_remove),
+	.driver		= {
+		.name	= "exynos4-fb",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init fimd_init(void)
+{
+	return platform_driver_register(&fimd_driver);
+}
+
+static void __exit fimd_exit(void)
+{
+	platform_driver_unregister(&fimd_driver);
+}
+
+module_init(fimd_init);
+module_exit(fimd_exit);
+
+MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
+MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
+MODULE_DESCRIPTION("Samsung DRM FIMD Driver");
+MODULE_LICENSE("GPL");