services/3rdparty/dc_fbdev/dc_fbdev.c

/*************************************************************************/ /*!
@File
@Copyright      Copyright (c) Imagination Technologies Ltd. All Rights Reserved
@License        MIT

The contents of this file are subject to the MIT license as set out below.

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, sublicense, 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 shall be included in
all copies or substantial portions of the Software.

This License is also included in this distribution in the file called
"MIT-COPYING".

EXCEPT AS OTHERWISE STATED IN A NEGOTIATED AGREEMENT: (A) 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 NONINFRINGEMENT; AND (B) IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS 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.
*/ /**************************************************************************/

#include <linux/console.h>
#include <linux/module.h>
#include <linux/fb.h>

#include "kerneldisplay.h"
#include "powervr/imgpixfmts.h"
#include "pvrmodule.h" /* for MODULE_LICENSE() */

#if !defined(CONFIG_FB)
#error dc_fbdev needs Linux framebuffer support. Enable it in your kernel.
#endif

#define DRVNAME					"dc_fbdev"
#define DC_PHYS_HEAP_ID			0
#define MAX_COMMANDS_IN_FLIGHT	2

#if defined(DC_FBDEV_NUM_PREFERRED_BUFFERS)
#define NUM_PREFERRED_BUFFERS	DC_FBDEV_NUM_PREFERRED_BUFFERS
#else
#define NUM_PREFERRED_BUFFERS	2
#endif

#define FALLBACK_REFRESH_RATE		60
#define FALLBACK_DPI		        160

typedef struct
{
	IMG_HANDLE			hSrvHandle;
	IMG_UINT32			ePixFormat;
	struct fb_info		*psLINFBInfo;
	bool				bCanFlip;
}
DC_FBDEV_DEVICE;

typedef struct
{
	DC_FBDEV_DEVICE		*psDeviceData;
	IMG_HANDLE			hLastConfigData;
	IMG_UINT32		ui32AllocUseMask;
}
DC_FBDEV_CONTEXT;

typedef struct
{
	DC_FBDEV_CONTEXT	*psDeviceContext;
	IMG_UINT32			ui32Width;
	IMG_UINT32			ui32Height;
	IMG_UINT32			ui32ByteStride;
	IMG_UINT32			ui32BufferID;
}
DC_FBDEV_BUFFER;

static DC_FBDEV_DEVICE *gpsDeviceData;


static
void DC_FBDEV_GetInfo(IMG_HANDLE hDeviceData,
						  DC_DISPLAY_INFO *psDisplayInfo)
{
	PVR_UNREFERENCED_PARAMETER(hDeviceData);

	strncpy(psDisplayInfo->szDisplayName, DRVNAME " 1", DC_NAME_SIZE);

	psDisplayInfo->ui32MinDisplayPeriod	= 0;
	psDisplayInfo->ui32MaxDisplayPeriod	= 1;
	psDisplayInfo->ui32MaxPipes			= 1;
	psDisplayInfo->bUnlatchedSupported	= IMG_FALSE;
}

static
PVRSRV_ERROR DC_FBDEV_PanelQueryCount(IMG_HANDLE hDeviceData,
									  IMG_UINT32 *pui32NumPanels)
{
	PVR_UNREFERENCED_PARAMETER(hDeviceData);
	*pui32NumPanels = 1;
	return PVRSRV_OK;
}

static
PVRSRV_ERROR DC_FBDEV_PanelQuery(IMG_HANDLE hDeviceData,
								 IMG_UINT32 ui32PanelsArraySize,
								 IMG_UINT32 *pui32NumPanels,
								 PVRSRV_PANEL_INFO *psPanelInfo)
{
	DC_FBDEV_DEVICE *psDeviceData = hDeviceData;
	struct fb_var_screeninfo *psVar = &psDeviceData->psLINFBInfo->var;
	struct fb_var_screeninfo sVar = { .pixclock = 0 };

	if(!lock_fb_info(psDeviceData->psLINFBInfo))
		return PVRSRV_ERROR_RETRY;

	*pui32NumPanels = 1;

	psPanelInfo[0].sSurfaceInfo.sFormat.ePixFormat = psDeviceData->ePixFormat;
	psPanelInfo[0].sSurfaceInfo.sDims.ui32Width    = psVar->xres;
	psPanelInfo[0].sSurfaceInfo.sDims.ui32Height   = psVar->yres;
	psPanelInfo[0].sSurfaceInfo.sFormat.eMemLayout = PVRSRV_SURFACE_MEMLAYOUT_STRIDED;
	psPanelInfo[0].sSurfaceInfo.sFormat.u.sFBCLayout.eFBCompressionMode = IMG_FB_COMPRESSION_NONE;

	/* Conformant fbdev drivers should have `var' and mode in sync by now,
	 * but some don't (like drmfb), so try a couple of different ways to
	 * get the info before falling back to the default.
	 */
	if(psVar->xres > 0 && psVar->yres > 0 && psVar->pixclock > 0)
		sVar = *psVar;
	else if(psDeviceData->psLINFBInfo->mode)
		fb_videomode_to_var(&sVar, psDeviceData->psLINFBInfo->mode);

	/* Override the refresh rate when defined. */
#ifdef DC_FBDEV_REFRESH
	psPanelInfo[0].ui32RefreshRate = DC_FBDEV_REFRESH;
#else
	if(sVar.xres > 0 && sVar.yres > 0 && sVar.pixclock > 0)
	{
		psPanelInfo[0].ui32RefreshRate = 1000000000LU /
			((sVar.upper_margin + sVar.lower_margin +
			  sVar.yres + sVar.vsync_len) *
			 (sVar.left_margin  + sVar.right_margin +
			  sVar.xres + sVar.hsync_len) *
			 (sVar.pixclock / 1000));
	}
	else
		psPanelInfo[0].ui32RefreshRate = FALLBACK_REFRESH_RATE;
#endif

	psPanelInfo[0].ui32XDpi =
		((int)sVar.width > 0) ? (254000 / sVar.width * psVar->xres / 10000) : FALLBACK_DPI;

	psPanelInfo[0].ui32YDpi	=
		((int)sVar.height > 0) ? 254000 / sVar.height * psVar->yres / 10000 : FALLBACK_DPI;

	unlock_fb_info(psDeviceData->psLINFBInfo);
	return PVRSRV_OK;
}

static
PVRSRV_ERROR DC_FBDEV_FormatQuery(IMG_HANDLE hDeviceData,
								  IMG_UINT32 ui32NumFormats,
								  PVRSRV_SURFACE_FORMAT *pasFormat,
								  IMG_UINT32 *pui32Supported)
{
	DC_FBDEV_DEVICE *psDeviceData = hDeviceData;
	int i;

	for(i = 0; i < ui32NumFormats; i++)
	{
		pui32Supported[i] = 0;

		if(pasFormat[i].ePixFormat == psDeviceData->ePixFormat)
			pui32Supported[i]++;
	}

	return PVRSRV_OK;
}

static
PVRSRV_ERROR DC_FBDEV_DimQuery(IMG_HANDLE hDeviceData,
							   IMG_UINT32 ui32NumDims,
							   PVRSRV_SURFACE_DIMS *psDim,
							   IMG_UINT32 *pui32Supported)
{
	DC_FBDEV_DEVICE *psDeviceData = hDeviceData;
	struct fb_var_screeninfo *psVar = &psDeviceData->psLINFBInfo->var;
	int i;

	if(!lock_fb_info(psDeviceData->psLINFBInfo))
		return PVRSRV_ERROR_RETRY;

	for(i = 0; i < ui32NumDims; i++)
	{
		pui32Supported[i] = 0;

		if(psDim[i].ui32Width  == psVar->xres &&
		   psDim[i].ui32Height == psVar->yres)
			pui32Supported[i]++;
	}

	unlock_fb_info(psDeviceData->psLINFBInfo);
	return PVRSRV_OK;
}

static
PVRSRV_ERROR DC_FBDEV_ContextCreate(IMG_HANDLE hDeviceData,
									IMG_HANDLE *hDisplayContext)
{
	DC_FBDEV_CONTEXT *psDeviceContext;
	PVRSRV_ERROR eError = PVRSRV_OK;

	psDeviceContext = kzalloc(sizeof(DC_FBDEV_CONTEXT), GFP_KERNEL);
	if(!psDeviceContext)
	{
		eError = PVRSRV_ERROR_OUT_OF_MEMORY;
		goto err_out;
	}

	psDeviceContext->psDeviceData = hDeviceData;
	*hDisplayContext = psDeviceContext;

err_out:
	return eError;
}

static PVRSRV_ERROR
DC_FBDEV_ContextConfigureCheck(IMG_HANDLE hDisplayContext,
							   IMG_UINT32 ui32PipeCount,
							   PVRSRV_SURFACE_CONFIG_INFO *pasSurfAttrib,
							   IMG_HANDLE *ahBuffers)
{
	DC_FBDEV_CONTEXT *psDeviceContext = hDisplayContext;
	DC_FBDEV_DEVICE *psDeviceData = psDeviceContext->psDeviceData;
	struct fb_var_screeninfo *psVar = &psDeviceData->psLINFBInfo->var;
	DC_FBDEV_BUFFER *psBuffer;
	PVRSRV_ERROR eError;

	if(ui32PipeCount != 1)
	{
		eError = PVRSRV_ERROR_DC_TOO_MANY_PIPES;
		goto err_out;
	}

	if(!ahBuffers)
	{
		eError = PVRSRV_ERROR_DC_INVALID_CONFIG;
		goto err_out;
	}

	if(!lock_fb_info(psDeviceData->psLINFBInfo))
	{
		eError = PVRSRV_ERROR_RETRY;
		goto err_out;
	}

	psBuffer = ahBuffers[0];

	if(pasSurfAttrib[0].sCrop.sDims.ui32Width  != psVar->xres ||
	   pasSurfAttrib[0].sCrop.sDims.ui32Height != psVar->yres ||
	   pasSurfAttrib[0].sCrop.i32XOffset != 0 ||
	   pasSurfAttrib[0].sCrop.i32YOffset != 0)
	{
		eError = PVRSRV_ERROR_DC_INVALID_CROP_RECT;
		goto err_unlock;
	}

	if(pasSurfAttrib[0].sDisplay.sDims.ui32Width !=
	   pasSurfAttrib[0].sCrop.sDims.ui32Width ||
	   pasSurfAttrib[0].sDisplay.sDims.ui32Height !=
	   pasSurfAttrib[0].sCrop.sDims.ui32Height ||
	   pasSurfAttrib[0].sDisplay.i32XOffset !=
	   pasSurfAttrib[0].sCrop.i32XOffset ||
	   pasSurfAttrib[0].sDisplay.i32YOffset !=
	   pasSurfAttrib[0].sCrop.i32YOffset)
	{
		eError = PVRSRV_ERROR_DC_INVALID_DISPLAY_RECT;
		goto err_unlock;
	}

	if(psBuffer->ui32Width  != psVar->xres &&
	   psBuffer->ui32Height != psVar->yres)
	{
		eError = PVRSRV_ERROR_DC_INVALID_BUFFER_DIMS;
		goto err_unlock;
	}

	eError = PVRSRV_OK;
err_unlock:
	unlock_fb_info(psDeviceData->psLINFBInfo);
err_out:
	return eError;
}

static
void DC_FBDEV_ContextConfigure(IMG_HANDLE hDisplayContext,
								   IMG_UINT32 ui32PipeCount,
								   PVRSRV_SURFACE_CONFIG_INFO *pasSurfAttrib,
								   IMG_HANDLE *ahBuffers,
								   IMG_UINT32 ui32DisplayPeriod,
								   IMG_HANDLE hConfigData)
{
	DC_FBDEV_CONTEXT *psDeviceContext = hDisplayContext;
	DC_FBDEV_DEVICE *psDeviceData = psDeviceContext->psDeviceData;
	struct fb_var_screeninfo sVar = psDeviceData->psLINFBInfo->var;
	int err;

	PVR_UNREFERENCED_PARAMETER(ui32PipeCount);
	PVR_UNREFERENCED_PARAMETER(pasSurfAttrib);
	PVR_UNREFERENCED_PARAMETER(ui32DisplayPeriod);

	if(psDeviceContext->hLastConfigData)
		DCDisplayConfigurationRetired(psDeviceContext->hLastConfigData);

	sVar.yoffset = 0;

	if(ui32PipeCount == 0)
	{
		/* If the pipe count is zero, we're tearing down. Don't record
		 * any new configurations, but still allow the display to pan
		 * back to buffer 0.
		 */ 
		psDeviceContext->hLastConfigData = NULL;

		/*
			We still need to "retire" this NULL flip as that signals back to
			the DC core that we've finished doing what we need to do
			and it can destroy the display context
		*/
		DCDisplayConfigurationRetired(hConfigData);
	}
	else
	{
		BUG_ON(ahBuffers == NULL);

		if(psDeviceData->bCanFlip)
		{
			DC_FBDEV_BUFFER *psBuffer = ahBuffers[0];
			sVar.yoffset = sVar.yres * psBuffer->ui32BufferID;
		}

		psDeviceContext->hLastConfigData = hConfigData;
	}

	if(lock_fb_info(psDeviceData->psLINFBInfo))
	{
		console_lock();

		/* If we're supposed to be able to flip, but the yres_virtual
		 * has been changed to an unsupported (smaller) value, we need
		 * to change it back (this is a workaround for some Linux fbdev
		 * drivers that seem to lose any modifications to yres_virtual
		 * after a blank.)
		 */
		if(psDeviceData->bCanFlip &&
		   sVar.yres_virtual < sVar.yres * NUM_PREFERRED_BUFFERS)
		{
			sVar.activate = FB_ACTIVATE_NOW;
			sVar.yres_virtual = sVar.yres * NUM_PREFERRED_BUFFERS;

			err = fb_set_var(psDeviceData->psLINFBInfo, &sVar);
			if(err)
				pr_err("fb_set_var failed (err=%d)\n", err);
		}
		else
		{
			err = fb_pan_display(psDeviceData->psLINFBInfo, &sVar);
			if(err)
				pr_err("fb_pan_display failed (err=%d)\n", err);
		}

		console_unlock();
		unlock_fb_info(psDeviceData->psLINFBInfo);
	}
}

static
void DC_FBDEV_ContextDestroy(IMG_HANDLE hDisplayContext)
{
	DC_FBDEV_CONTEXT *psDeviceContext = hDisplayContext;

	BUG_ON(psDeviceContext->hLastConfigData != NULL);
	kfree(psDeviceContext);
}

static
IMG_BOOL DC_FBDEV_GetBufferID(DC_FBDEV_CONTEXT *psDeviceContext, IMG_UINT32 *pui32BufferID)
{
	IMG_UINT32 ui32BufferID;

	/* If we don't support flipping, allow this code to give every
	 * allocated buffer the same ID. This means that the display
	 * won't be panned, and the same page list will be used for
	 * every allocation.
	 */
	if (!psDeviceContext->psDeviceData->bCanFlip)
	{
		*pui32BufferID = 0;
		return IMG_TRUE;
	}

	for (ui32BufferID = 0; ui32BufferID < NUM_PREFERRED_BUFFERS; ++ui32BufferID)
	{
		if ((psDeviceContext->ui32AllocUseMask & (1UL << ui32BufferID)) == 0)
		{
			psDeviceContext->ui32AllocUseMask |= (1UL << ui32BufferID);
			
			*pui32BufferID = ui32BufferID;

			return IMG_TRUE;
		}
	}
	return IMG_FALSE;
}

static
void DC_FBDEV_PutBufferID(DC_FBDEV_CONTEXT *psDeviceContext, IMG_UINT32 ui32BufferID)
{
	psDeviceContext->ui32AllocUseMask &= ~(1UL << ui32BufferID);
}

#define BYTE_TO_PAGES(range) (((range) + (PAGE_SIZE - 1)) >> PAGE_SHIFT)

static
PVRSRV_ERROR DC_FBDEV_BufferAlloc(IMG_HANDLE hDisplayContext,
								  DC_BUFFER_CREATE_INFO *psCreateInfo,
								  IMG_DEVMEM_LOG2ALIGN_T *puiLog2PageSize,
								  IMG_UINT32 *pui32PageCount,
								  IMG_UINT32 *pui32PhysHeapID,
								  IMG_UINT32 *pui32ByteStride,
								  IMG_HANDLE *phBuffer)
{
	DC_FBDEV_CONTEXT *psDeviceContext = hDisplayContext;
	DC_FBDEV_DEVICE *psDeviceData = psDeviceContext->psDeviceData;
	PVRSRV_SURFACE_INFO *psSurfInfo = &psCreateInfo->sSurface;
	PVRSRV_ERROR eError;
	DC_FBDEV_BUFFER *psBuffer;
	IMG_UINT32 ui32ByteSize;

	if (psSurfInfo->sFormat.ePixFormat != psDeviceData->ePixFormat)
	{
		eError = PVRSRV_ERROR_UNSUPPORTED_PIXEL_FORMAT;
		goto err_out;
	}

	psBuffer = kmalloc(sizeof(DC_FBDEV_BUFFER), GFP_KERNEL);
	if (!psBuffer)
	{
		eError = PVRSRV_ERROR_OUT_OF_MEMORY;
		goto err_out;
	}

	psBuffer->psDeviceContext = psDeviceContext;
	psBuffer->ui32ByteStride =
		psSurfInfo->sDims.ui32Width * psCreateInfo->ui32BPP;

	psBuffer->ui32Width = psSurfInfo->sDims.ui32Width;
	psBuffer->ui32Height = psSurfInfo->sDims.ui32Height;

	if (!DC_FBDEV_GetBufferID(psDeviceContext, &psBuffer->ui32BufferID))
	{
		eError = PVRSRV_ERROR_OUT_OF_MEMORY;
		goto err_free;
	}

	ui32ByteSize = psBuffer->ui32ByteStride * psBuffer->ui32Height;

	*puiLog2PageSize = PAGE_SHIFT;
	*pui32PageCount	 = BYTE_TO_PAGES(ui32ByteSize);
	*pui32PhysHeapID = DC_PHYS_HEAP_ID;
	*pui32ByteStride = psBuffer->ui32ByteStride;
	*phBuffer	 = psBuffer;

	return PVRSRV_OK;

err_free:
	kfree(psBuffer);

err_out:
	return eError;
}

static
PVRSRV_ERROR DC_FBDEV_BufferAcquire(IMG_HANDLE hBuffer,
									IMG_DEV_PHYADDR *pasDevPAddr,
									void **ppvLinAddr)
{
	DC_FBDEV_BUFFER *psBuffer = hBuffer;
	DC_FBDEV_DEVICE *psDeviceData = psBuffer->psDeviceContext->psDeviceData;
	IMG_UINT32 ui32ByteSize = psBuffer->ui32ByteStride * psBuffer->ui32Height;
	uintptr_t uiStartAddr;
	IMG_UINT32 i, ui32MaxLen;

#if defined(DC_FBDEV_USE_SCREEN_BASE)
	uiStartAddr = (uintptr_t)psDeviceData->psLINFBInfo->screen_base;
#else
	uiStartAddr = psDeviceData->psLINFBInfo->fix.smem_start;
#endif

	uiStartAddr += psBuffer->ui32BufferID * ui32ByteSize;
	ui32MaxLen = psDeviceData->psLINFBInfo->fix.smem_len -
				 psBuffer->ui32BufferID * ui32ByteSize;

	for (i = 0; i < BYTE_TO_PAGES(ui32ByteSize); i++)
	{
		BUG_ON(i * PAGE_SIZE >= ui32MaxLen);
		pasDevPAddr[i].uiAddr = uiStartAddr + (i * PAGE_SIZE);
#if defined(DC_FBDEV_USE_SCREEN_BASE)
		pasDevPAddr[i].uiAddr =
			page_to_phys(vmalloc_to_page((void *)(uintptr_t)pasDevPAddr[i].uiAddr));
#endif
	}

	/* We're UMA, so services will do the right thing and make
	 * its own CPU virtual address mapping for the buffer.
	 */
	*ppvLinAddr = NULL;

	return PVRSRV_OK;
}

static void DC_FBDEV_BufferRelease(IMG_HANDLE hBuffer)
{
	PVR_UNREFERENCED_PARAMETER(hBuffer);
}

static void DC_FBDEV_BufferFree(IMG_HANDLE hBuffer)
{
	DC_FBDEV_BUFFER *psBuffer = hBuffer;

	DC_FBDEV_PutBufferID(psBuffer->psDeviceContext, psBuffer->ui32BufferID);

	kfree(psBuffer);
}

/* If we can flip, we need to make sure we have the memory to do so.
 *
 * We'll assume that the fbdev device provides extra space in
 * yres_virtual for panning; xres_virtual is theoretically supported,
 * but it involves more work.
 *
 * If the fbdev device doesn't have yres_virtual > yres, we'll try
 * requesting it before bailing. Userspace applications commonly do
 * this with an FBIOPUT_VSCREENINFO ioctl().
 *
 * Another problem is with a limitation in the services DC -- it
 * needs framebuffers to be page aligned (this is a SW limitation,
 * the HW can support non-page-aligned buffers). So we have to
 * check that stride * height for a single buffer is page aligned.
 */

static bool DC_FBDEV_FlipPossible(struct fb_info *psLINFBInfo)
{
	struct fb_var_screeninfo sVar = psLINFBInfo->var;
	int err;

	if(!psLINFBInfo->fix.xpanstep && !psLINFBInfo->fix.ypanstep &&
	   !psLINFBInfo->fix.ywrapstep)
	{
		pr_err("The fbdev device detected does not support ypan/ywrap. "
			   "Flipping disabled.\n");
		return false;
	}

	if((psLINFBInfo->fix.line_length * sVar.yres) % PAGE_SIZE != 0)
	{
		pr_err("Line length (in bytes) x yres is not a multiple of "
			   "page size. Flipping disabled.\n");
		return false;
	}

	/* We might already have enough space */
	if(sVar.yres * NUM_PREFERRED_BUFFERS <= sVar.yres_virtual)
		return true;

	pr_err("No buffer space for flipping; asking for more.\n");

	sVar.activate = FB_ACTIVATE_NOW;
	sVar.yres_virtual = sVar.yres * NUM_PREFERRED_BUFFERS;

	err = fb_set_var(psLINFBInfo, &sVar);
	if(err)
	{
		pr_err("fb_set_var failed (err=%d). Flipping disabled.\n", err);
		return false;
	}

	if(sVar.yres * NUM_PREFERRED_BUFFERS > sVar.yres_virtual)
	{
		pr_err("Failed to obtain additional buffer space. "
			   "Flipping disabled.\n");
		return false;
	}

	/* Some fbdev drivers allow the yres_virtual modification through,
	 * but don't actually update the fix. We need the fix to be updated
	 * and more memory allocated, so we can actually take advantage of
	 * the increased yres_virtual.
	 */
	if(psLINFBInfo->fix.smem_len < psLINFBInfo->fix.line_length * sVar.yres_virtual)
	{
		pr_err("'fix' not re-allocated with sufficient buffer space. "
			   "Flipping disabled.\n");
		return false;
	}

	return true;
}

static int __init DC_FBDEV_init(void)
{
	static DC_DEVICE_FUNCTIONS sDCFunctions =
	{
		.pfnGetInfo					= DC_FBDEV_GetInfo,
		.pfnPanelQueryCount			= DC_FBDEV_PanelQueryCount,
		.pfnPanelQuery				= DC_FBDEV_PanelQuery,
		.pfnFormatQuery				= DC_FBDEV_FormatQuery,
		.pfnDimQuery				= DC_FBDEV_DimQuery,
		.pfnSetBlank				= NULL,
		.pfnSetVSyncReporting		= NULL,
		.pfnLastVSyncQuery			= NULL,
		.pfnContextCreate			= DC_FBDEV_ContextCreate,
		.pfnContextDestroy			= DC_FBDEV_ContextDestroy,
		.pfnContextConfigure		= DC_FBDEV_ContextConfigure,
		.pfnContextConfigureCheck	= DC_FBDEV_ContextConfigureCheck,
		.pfnBufferAlloc				= DC_FBDEV_BufferAlloc,
		.pfnBufferAcquire			= DC_FBDEV_BufferAcquire,
		.pfnBufferRelease			= DC_FBDEV_BufferRelease,
		.pfnBufferFree				= DC_FBDEV_BufferFree,
	};

	struct fb_info *psLINFBInfo;
	IMG_PIXFMT ePixFormat;
	int err = -ENODEV;

	psLINFBInfo = registered_fb[0];
	if(!psLINFBInfo)
	{
		pr_err("No Linux framebuffer (fbdev) device is registered!\n"
			   "Check you have a framebuffer driver compiled into your "
			   "kernel\nand that it is enabled on the cmdline.\n");
		goto err_out;
	}

	if(!lock_fb_info(psLINFBInfo))
		goto err_out;

	console_lock();

	/* Filter out broken FB devices */
	if(!psLINFBInfo->fix.smem_len || !psLINFBInfo->fix.line_length)
	{
		pr_err("The fbdev device detected had a zero smem_len or "
			   "line_length,\nwhich suggests it is a broken driver.\n");
		goto err_unlock;
	}

	if(psLINFBInfo->fix.type != FB_TYPE_PACKED_PIXELS ||
	   psLINFBInfo->fix.visual != FB_VISUAL_TRUECOLOR)
	{
		pr_err("The fbdev device detected is not truecolor with packed "
			   "pixels.\n");
		goto err_unlock;
	}

	if(psLINFBInfo->var.bits_per_pixel == 32)
	{
		if(psLINFBInfo->var.red.length   != 8  ||
		   psLINFBInfo->var.green.length != 8  ||
		   psLINFBInfo->var.blue.length  != 8  ||
		   psLINFBInfo->var.red.offset   != 16 ||
		   psLINFBInfo->var.green.offset != 8  ||
		   psLINFBInfo->var.blue.offset  != 0)
		{
			pr_err("The fbdev device detected uses an unrecognized "
				   "32bit pixel format (%u/%u/%u, %u/%u/%u)\n",
				   psLINFBInfo->var.red.length,
				   psLINFBInfo->var.green.length,
				   psLINFBInfo->var.blue.length,
				   psLINFBInfo->var.red.offset,
				   psLINFBInfo->var.green.offset,
				   psLINFBInfo->var.blue.offset);
			goto err_unlock;
		}
#if defined(DC_FBDEV_FORCE_XRGB8888)
		ePixFormat = IMG_PIXFMT_B8G8R8X8_UNORM;
#else
		ePixFormat = IMG_PIXFMT_B8G8R8A8_UNORM;
#endif
	}
	else if(psLINFBInfo->var.bits_per_pixel == 16)
	{
		if(psLINFBInfo->var.red.length   != 5  ||
		   psLINFBInfo->var.green.length != 6  ||
		   psLINFBInfo->var.blue.length  != 5  ||
		   psLINFBInfo->var.red.offset   != 11 ||
		   psLINFBInfo->var.green.offset != 5  ||
		   psLINFBInfo->var.blue.offset  != 0)
		{
			pr_err("The fbdev device detected uses an unrecognized "
				   "16bit pixel format (%u/%u/%u, %u/%u/%u)\n",
				   psLINFBInfo->var.red.length,
				   psLINFBInfo->var.green.length,
				   psLINFBInfo->var.blue.length,
				   psLINFBInfo->var.red.offset,
				   psLINFBInfo->var.green.offset,
				   psLINFBInfo->var.blue.offset);
			goto err_unlock;
		}
		ePixFormat = IMG_PIXFMT_B5G6R5_UNORM;
	}
	else
	{
		pr_err("The fbdev device detected uses an unsupported "
			   "bpp (%u).\n", psLINFBInfo->var.bits_per_pixel);
		goto err_unlock;
	}

	if(!try_module_get(psLINFBInfo->fbops->owner))
	{
		pr_err("try_module_get() failed");
		goto err_unlock;
	}

	if(psLINFBInfo->fbops->fb_open &&
	   psLINFBInfo->fbops->fb_open(psLINFBInfo, 0) != 0)
	{
		pr_err("fb_open() failed");
		goto err_module_put;
	}

	gpsDeviceData = kmalloc(sizeof(DC_FBDEV_DEVICE), GFP_KERNEL);
	if(!gpsDeviceData)
		goto err_module_put;

	gpsDeviceData->psLINFBInfo = psLINFBInfo;
	gpsDeviceData->ePixFormat = ePixFormat;

	if(DCRegisterDevice(&sDCFunctions,
						MAX_COMMANDS_IN_FLIGHT,
						gpsDeviceData,
						&gpsDeviceData->hSrvHandle) != PVRSRV_OK)
		goto err_kfree;

	gpsDeviceData->bCanFlip = DC_FBDEV_FlipPossible(psLINFBInfo);

	pr_info("Found usable fbdev device (%s):\n"
			"range (physical) = 0x%lx-0x%lx\n"
			"size (bytes)     = 0x%x\n"
			"xres x yres      = %ux%u\n"
			"xres x yres (v)  = %ux%u\n"
			"img pix fmt      = %u\n"
			"flipping?        = %d\n",
			psLINFBInfo->fix.id,
			psLINFBInfo->fix.smem_start,
			psLINFBInfo->fix.smem_start + psLINFBInfo->fix.smem_len,
			psLINFBInfo->fix.smem_len,
			psLINFBInfo->var.xres, psLINFBInfo->var.yres,
			psLINFBInfo->var.xres_virtual, psLINFBInfo->var.yres_virtual,
			ePixFormat, gpsDeviceData->bCanFlip);
	err = 0;
err_unlock:
	console_unlock();
	unlock_fb_info(psLINFBInfo);
err_out:
	return err;
err_kfree:
	kfree(gpsDeviceData);
err_module_put:
	module_put(psLINFBInfo->fbops->owner);
	goto err_unlock;
}

static void __exit DC_FBDEV_exit(void)
{
	DC_FBDEV_DEVICE *psDeviceData = gpsDeviceData;
	struct fb_info *psLINFBInfo = psDeviceData->psLINFBInfo;

	lock_fb_info(psLINFBInfo);
	console_lock();

    if(psLINFBInfo->fbops->fb_release)
	   psLINFBInfo->fbops->fb_release(psLINFBInfo, 0);

	module_put(psLINFBInfo->fbops->owner);

	console_unlock();
	unlock_fb_info(psLINFBInfo);

	DCUnregisterDevice(psDeviceData->hSrvHandle);
	kfree(psDeviceData);
}

module_init(DC_FBDEV_init);
module_exit(DC_FBDEV_exit);