/*
 * Copyright (C) 2010 ARM Limited. All rights reserved.
 *
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <linux/fb.h>

#include <cutils/log.h>
#include <cutils/atomic.h>
#include <hardware/hardware.h>
#include <hardware/gralloc.h>

#include <GLES/gl.h>

#include "alloc_device.h"
#include "gralloc_priv.h"
#include "gralloc_helper.h"
#include "gralloc_vsync.h"

#define STANDARD_LINUX_SCREEN

// numbers of buffers for page flipping
#define NUM_BUFFERS NUM_FB_BUFFERS 

enum
{
	PAGE_FLIP = 0x00000001,
};


static int fb_set_swap_interval(struct framebuffer_device_t* dev, int interval)
{
	if (interval < dev->minSwapInterval)
	{
		interval = dev->minSwapInterval;
	}
	else if (interval > dev->maxSwapInterval)
	{
		interval = dev->maxSwapInterval;
	}

	private_module_t* m = reinterpret_cast<private_module_t*>(dev->common.module);
	m->swapInterval = interval;

	if (0 == interval) gralloc_vsync_disable(dev);
	else gralloc_vsync_enable(dev);

	return 0;
}

static int fb_post(struct framebuffer_device_t* dev, buffer_handle_t buffer)
{
	if (private_handle_t::validate(buffer) < 0)
	{
		return -EINVAL;
	}

	private_handle_t const* hnd = reinterpret_cast<private_handle_t const*>(buffer);
	private_module_t* m = reinterpret_cast<private_module_t*>(dev->common.module);

	if (m->currentBuffer)
	{
		m->base.unlock(&m->base, m->currentBuffer);
		m->currentBuffer = 0;
	}

	if (hnd->flags & private_handle_t::PRIV_FLAGS_FRAMEBUFFER)
	{
		m->base.lock(&m->base, buffer, private_module_t::PRIV_USAGE_LOCKED_FOR_POST, 
				0, 0, m->info.xres, m->info.yres, NULL);

		const size_t offset = (uintptr_t)hnd->base - (uintptr_t)m->framebuffer->base;
		int interrupt;
		m->info.activate = FB_ACTIVATE_VBL;
		m->info.yoffset = offset / m->finfo.line_length;

#ifdef STANDARD_LINUX_SCREEN
		if (ioctl(m->framebuffer->fd, FBIOPAN_DISPLAY, &m->info) == -1) 
		{
			AERR( "FBIOPAN_DISPLAY failed for fd: %d", m->framebuffer->fd );
			m->base.unlock(&m->base, buffer); 
			return -errno;
		}
#else /*Standard Android way*/
		if (ioctl(m->framebuffer->fd, FBIOPUT_VSCREENINFO, &m->info) == -1) 
		{
			AERR( "FBIOPUT_VSCREENINFO failed for fd: %d", m->framebuffer->fd );
			m->base.unlock(&m->base, buffer); 
			return -errno;
		}
#endif
		if ( 0 != gralloc_wait_for_vsync(dev) )
		{
			AERR( "Gralloc wait for vsync failed for fd: %d", m->framebuffer->fd );
			m->base.unlock(&m->base, buffer); 
			return -errno;
		}
		m->currentBuffer = buffer;
	} 
	else
	{
		void* fb_vaddr;
		void* buffer_vaddr;

		m->base.lock(&m->base, m->framebuffer, GRALLOC_USAGE_SW_WRITE_RARELY, 
				0, 0, m->info.xres, m->info.yres, &fb_vaddr);

		m->base.lock(&m->base, buffer, GRALLOC_USAGE_SW_READ_RARELY, 
				0, 0, m->info.xres, m->info.yres, &buffer_vaddr);

		// If buffer's alignment match framebuffer alignment we can do a direct copy.
		// If not we must fallback to do an aligned copy of each line.
		if ( hnd->byte_stride == (int)m->finfo.line_length )
		{
			memcpy(fb_vaddr, buffer_vaddr, m->finfo.line_length * m->info.yres);
		}
		else
		{
			uintptr_t fb_offset = 0;
			uintptr_t buffer_offset = 0;
			unsigned int i;

			for (i = 0; i < m->info.yres; i++)
			{
				memcpy((void *)((uintptr_t)fb_vaddr + fb_offset),
					   (void *)((uintptr_t)buffer_vaddr + buffer_offset),
					   m->finfo.line_length);

				fb_offset += m->finfo.line_length;
				buffer_offset += hnd->byte_stride;
			}
		}
		m->base.unlock(&m->base, buffer); 
		m->base.unlock(&m->base, m->framebuffer); 
	}

	return 0;
}

int init_frame_buffer_locked(struct private_module_t* module)
{
	if (module->framebuffer)
	{
		return 0; // Nothing to do, already initialized
	}
        
	char const * const device_template[] =
	{
		"/dev/graphics/fb%u",
		"/dev/fb%u",
		NULL
	};

	int fd = -1;
	int i = 0;
	char name[64];

	while ((fd == -1) && device_template[i])
	{
		snprintf(name, 64, device_template[i], 0);
		fd = open(name, O_RDWR, 0);
		i++;
	}

	if (fd < 0)
	{
		return -errno;
	}

	struct fb_fix_screeninfo finfo;
	if (ioctl(fd, FBIOGET_FSCREENINFO, &finfo) == -1)
	{
		return -errno;
	}

	struct fb_var_screeninfo info;
	if (ioctl(fd, FBIOGET_VSCREENINFO, &info) == -1)
	{
		return -errno;
	}

	info.reserved[0] = 0;
	info.reserved[1] = 0;
	info.reserved[2] = 0;
	info.xoffset = 0;
	info.yoffset = 0;
	info.activate = FB_ACTIVATE_NOW;

#ifdef GRALLOC_16_BITS
	/*
	 * Explicitly request 5/6/5
	 */
	info.bits_per_pixel = 16;
	info.red.offset     = 11;
	info.red.length     = 5;
	info.green.offset   = 5;
	info.green.length   = 6;
	info.blue.offset    = 0;
	info.blue.length    = 5;
	info.transp.offset  = 0;
	info.transp.length  = 0;
#else
	/*
	 * Explicitly request 8/8/8
	 */
	info.bits_per_pixel = 32;
	info.red.offset     = 16;
	info.red.length     = 8;
	info.green.offset   = 8;
	info.green.length   = 8;
	info.blue.offset    = 0;
	info.blue.length    = 8;
	info.transp.offset  = 0;
	info.transp.length  = 0;
#endif

	/*
	 * Request NUM_BUFFERS screens (at lest 2 for page flipping)
	 */
	info.yres_virtual = info.yres * NUM_BUFFERS;

	uint32_t flags = PAGE_FLIP;
	if (ioctl(fd, FBIOPUT_VSCREENINFO, &info) == -1)
	{
		info.yres_virtual = info.yres;
		flags &= ~PAGE_FLIP;
		AWAR( "FBIOPUT_VSCREENINFO failed, page flipping not supported fd: %d", fd );
	}

	if (info.yres_virtual < info.yres * 2)
	{
		// we need at least 2 for page-flipping
		info.yres_virtual = info.yres;
		flags &= ~PAGE_FLIP;
		AWAR( "page flipping not supported (yres_virtual=%d, requested=%d)", info.yres_virtual, info.yres*2 );
	}

	if (ioctl(fd, FBIOGET_VSCREENINFO, &info) == -1)
	{
		return -errno;
	}

	int refreshRate = 0;
	if ( info.pixclock > 0 )
	{
		refreshRate = 1000000000000000LLU /
		(
			uint64_t( info.upper_margin + info.lower_margin + info.yres + info.hsync_len )
			* ( info.left_margin  + info.right_margin + info.xres + info.vsync_len )
			* info.pixclock
		);
	}
	else
	{
		AWAR( "fbdev pixclock is zero for fd: %d", fd );
	}

	if (refreshRate == 0)
	{
		refreshRate = 60*1000;  // 60 Hz
	}

	if (int(info.width) <= 0 || int(info.height) <= 0)
	{
		// the driver doesn't return that information
		// default to 160 dpi
		info.width  = ((info.xres * 25.4f)/160.0f + 0.5f);
		info.height = ((info.yres * 25.4f)/160.0f + 0.5f);
	}

	float xdpi = (info.xres * 25.4f) / info.width;
	float ydpi = (info.yres * 25.4f) / info.height;
	float fps  = refreshRate / 1000.0f;

	AINF("using (fd=%d)\n"
	     "id           = %s\n"
	     "xres         = %d px\n"
	     "yres         = %d px\n"
	     "xres_virtual = %d px\n"
	     "yres_virtual = %d px\n"
	     "bpp          = %d\n"
	     "r            = %2u:%u\n"
	     "g            = %2u:%u\n"
	     "b            = %2u:%u\n",
	     fd,
	     finfo.id,
	     info.xres,
	     info.yres,
	     info.xres_virtual,
	     info.yres_virtual,
	     info.bits_per_pixel,
	     info.red.offset, info.red.length,
	     info.green.offset, info.green.length,
	     info.blue.offset, info.blue.length);

	AINF("width        = %d mm (%f dpi)\n"
	     "height       = %d mm (%f dpi)\n"
	     "refresh rate = %.2f Hz\n",
	     info.width,  xdpi,
	     info.height, ydpi,
	     fps);

	if (0 == strncmp(finfo.id, "CLCD FB", 7))
	{
		module->dpy_type = MALI_DPY_TYPE_CLCD;
	}
	else if (0 == strncmp(finfo.id, "ARM Mali HDLCD", 14))
	{
		module->dpy_type = MALI_DPY_TYPE_HDLCD;
	}
	else
	{
		module->dpy_type = MALI_DPY_TYPE_UNKNOWN;
	}

	if (ioctl(fd, FBIOGET_FSCREENINFO, &finfo) == -1)
	{
		return -errno;
	}

	if (finfo.smem_len <= 0)
	{
		return -errno;
	}

	module->flags = flags;
	module->info = info;
	module->finfo = finfo;
	module->xdpi = xdpi;
	module->ydpi = ydpi;
	module->fps = fps;
	module->swapInterval = 1;

	/*
	 * map the framebuffer
	 */
	size_t fbSize = round_up_to_page_size(finfo.line_length * info.yres_virtual);
	void* vaddr = mmap(0, fbSize, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
	if (vaddr == MAP_FAILED) 
	{
		AERR( "Error mapping the framebuffer (%s)", strerror(errno) );
		return -errno;
	}

	memset(vaddr, 0, fbSize);


	// Create a "fake" buffer object for the entire frame buffer memory, and store it in the module
	module->framebuffer = new private_handle_t(private_handle_t::PRIV_FLAGS_FRAMEBUFFER, GRALLOC_USAGE_HW_FB, fbSize, vaddr,
	                                           0, dup(fd), 0);

	module->numBuffers = info.yres_virtual / info.yres;
	module->bufferMask = 0;

	return 0;
}

static int init_frame_buffer(struct private_module_t* module)
{
	pthread_mutex_lock(&module->lock);
	int err = init_frame_buffer_locked(module);
	pthread_mutex_unlock(&module->lock);
	return err;
}

static int fb_close(struct hw_device_t *device)
{
	framebuffer_device_t* dev = reinterpret_cast<framebuffer_device_t*>(device);
	if (dev)
	{
		free(dev);
	}
	return 0;
}

int compositionComplete(struct framebuffer_device_t* dev)
{
	GRALLOC_UNUSED(dev);

	/* By doing a finish here we force the GL driver to start rendering
	   all the drawcalls up to this point, and to wait for the rendering to be complete.*/
	glFinish();
	/* The rendering of the backbuffer is now completed.
	   When SurfaceFlinger later does a call to eglSwapBuffer(), the swap will be done
	   synchronously in the same thread, and not asynchronoulsy in a background thread later.
	   The SurfaceFlinger requires this behaviour since it releases the lock on all the
	   SourceBuffers (Layers) after the compositionComplete() function returns.
	   However this "bad" behaviour by SurfaceFlinger should not affect performance, 
	   since the Applications that render the SourceBuffers (Layers) still get the 
	   full renderpipeline using asynchronous rendering. So they perform at maximum speed,
	   and because of their complexity compared to the Surface flinger jobs, the Surface flinger
	   is normally faster even if it does everyhing synchronous and serial. 
	   */
	return 0;
}

int framebuffer_device_open(hw_module_t const* module, const char* name, hw_device_t** device)
{
	int status = -EINVAL;

	GRALLOC_UNUSED(name);

	alloc_device_t* gralloc_device;
#if DISABLE_FRAMEBUFFER_HAL == 1
	AERR("Framebuffer HAL not support/disabled %s",
#ifdef MALI_DISPLAY_VERSION
	"with MALI display enable");
#else
	"");
#endif
	return -ENODEV;
#endif
	status = gralloc_open(module, &gralloc_device);
	if (status < 0)
	{
		return status;
	}

	private_module_t* m = (private_module_t*)module;
	status = init_frame_buffer(m);

	/* malloc is used instead of 'new' to instantiate the struct framebuffer_device_t
	 * C++11 spec specifies that if a class/struct has a const member,default constructor 
	 * is deleted. So, if 'new' is used to instantiate the class/struct, it will throw
	 * error complaining about deleted constructor. Even if the struct is wrapped in a class
	 * it will still try to use the base class constructor to initialize the members, resulting 
	 * in error 'deleted constructor'.
	 * This leaves two options 
	 * Option 1: initialize the const members at the instantiation time. With {value1, value2 ..}
	 * Which relies on the order of the members, and if members are reordered or a new member is introduced
	 * it will end up assiging wrong value to members. Designated assignment as well has been removed in C++11
	 * Option 2: use malloc instead of 'new' to allocate the class/struct and initialize the members in code. 
	 * This is the only maintainable option available.
	 */

	framebuffer_device_t *dev =  reinterpret_cast<framebuffer_device_t*> (malloc(sizeof(framebuffer_device_t)));

	/* if either or both of init_frame_buffer() and malloc failed */
	if ((status < 0) || (!dev))
	{
		gralloc_close(gralloc_device);
		(!dev)?	(void)(status = -ENOMEM) : free(dev);
		return status;
	}

	memset(dev, 0, sizeof(*dev));

	/* initialize the procs */
	dev->common.tag = HARDWARE_DEVICE_TAG;
	dev->common.version = 0;
	dev->common.module = const_cast<hw_module_t*>(module);
	dev->common.close = fb_close;
	dev->setSwapInterval = fb_set_swap_interval;
	dev->post = fb_post;
	dev->setUpdateRect = 0;
	dev->compositionComplete = &compositionComplete;

	int stride = m->finfo.line_length / (m->info.bits_per_pixel >> 3);
	const_cast<uint32_t&>(dev->flags) = 0;
	const_cast<uint32_t&>(dev->width) = m->info.xres;
	const_cast<uint32_t&>(dev->height) = m->info.yres;
	const_cast<int&>(dev->stride) = stride;
#ifdef GRALLOC_16_BITS
	const_cast<int&>(dev->format) = HAL_PIXEL_FORMAT_RGB_565;
#else
	const_cast<int&>(dev->format) = HAL_PIXEL_FORMAT_BGRA_8888;
#endif
	const_cast<float&>(dev->xdpi) = m->xdpi;
	const_cast<float&>(dev->ydpi) = m->ydpi;
	const_cast<float&>(dev->fps) = m->fps;
	const_cast<int&>(dev->minSwapInterval) = 0;
	const_cast<int&>(dev->maxSwapInterval) = 1;
	*device = &dev->common;

	gralloc_vsync_enable(dev);

	return status;
}