一.framebuffer device注册
1. framebuffer定义
在alps/kernel/mediatek/platform/mt6577/kernel/core/mt6577_devs.c中
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#if defined(CONFIG_MTK_FB)
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static u64 mtkfb_dmamask = ~(u32)0;
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static struct resource resource_fb[] = {
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{
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.start = 0, //初始化start=0x3fb00000
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.end = 0, //end=0x3fffffff
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.flags = IORESOURCE_MEM
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}
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};
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static struct platform_device mt6577_device_fb = {
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.name = "mtkfb", //名字为mtkfb,与驱动匹配时用到
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.id = 0,
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.num_resources = ARRAY_SIZE(resource_fb),
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.resource = resource_fb,
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.dev = {
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.dma_mask = &mtkfb_dmamask,
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.coherent_dma_mask = 0xffffffff,
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},
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};
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#endif
2. 设备注册
在
alps/kernel/mediatek/platform/mt6577/kernel/core/mt6577_devs.c中
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__init int mt6577_board_init(void)
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{
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#if defined(CONFIG_MTK_FB)
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if (((bl_fb.base == FB_START) && (bl_fb.size == FB_SIZE)) ||(use_bl_fb == 2)) {
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mtkfb_set_lcm_inited(1);
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}
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resource_fb[0].start = FB_START; //将start与end初始化
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resource_fb[0].end = FB_START + FB_SIZE - 1;
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retval = platform_device_register(&mt6577_device_fb); //注册平台设备
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#endif
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}
3. 关于FB_SIZE
本来是一个简简单的宏定义,这儿却是一个函数,而且是稍微有些复杂的函数.
在mt6577_board_init中有如下:
if (((bl_fb.base == FB_START) && (bl_fb.size == FB_SIZE))
用了宏FB_SIZE,其定义如下:
#define FB_SIZE (RESERVED_MEM_SIZE_FOR_FB)
#define RESERVED_MEM_SIZE_FOR_FB (DISP_GetVRamSizeBoot((char*)&temp_command_line))
在alps/kernel/mediatek/source/kernel/drivers/video/disp_drv.c中
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UINT32 DISP_GetVRamSizeBoot(char *cmdline)
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{
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static UINT32 vramSize = 0;
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if(vramSize)
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{
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return vramSize;
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}
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disp_get_lcm_name_boot(cmdline); //3.1 从字符串中解析出lcm的名字,并提取函数指针
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if(disp_drv)
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vramSize = DISP_GetVRamSize(); //3.2 获取fb_size,现在是5M
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vramSize = ALIGN_TO_POW_OF_2(vramSize, 0x100000);
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return vramSize;
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}
3.1 解析硬件名,并获取函数指针
DISP_GetVRamSizeBoot
--> disp_get_lcm_name_boot
在alps/kernel/mediatek/source/kernel/drivers/video/disp_drv.c中
从命令行中传入的参数是:
console=ttyMT0,921600n1 root=/dev/ram vmalloc=280M slub_max_order=0 lcm=1-nt35516_3d fps=6020
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char disp_lcm_name[256] = {0};
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BOOL disp_get_lcm_name_boot(char *cmdline) //从命令字符串中解析出lcm的名字,并提取函数指针
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{
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p = strstr(cmdline, "lcm="); //解析出lcm字符串后面的就是lcm设备
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if(p == NULL)
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return DISP_SelectDeviceBoot(NULL); //如果没有找到 ret false
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//找到之后将全局变量isLCMFound设为1
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isLCMFound = 1;
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//将lcm设备名nt35516保存在disp_lcm_name中,当然要去掉多余的"1-"
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strncpy((char*)disp_lcm_name, (const char*)p, (int)(q-p));
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if(DISP_SelectDeviceBoot(disp_lcm_name))
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ret = TRUE;
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}
3.1.1 从list中找到硬件,并调用具体的函数指针
DISP_GetVRamSizeBoot
--> disp_get_lcm_name_boot
-->
DISP_SelectDeviceBoot
在alps/kernel/mediatek/source/kernel/drivers/video/disp_drv.c中
初始化lcm_drv, lcm_params , disp_drv这三个全局变量
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BOOL DISP_SelectDeviceBoot(const char* lcm_name)
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{
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LCM_DRIVER *lcm = NULL;
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//全局变量lcm_count = sizeof(lcm_driver_list)/sizeof(LCM_DRIVER*);
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//这儿用到了lcm_driver_list,在projectConfig.mk中可以配置list的项
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for(i = 0;i < lcm_count;i++) //lcm_count=1
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{
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lcm_params = &s_lcm_params;
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lcm = lcm_driver_list[i];
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lcm->set_util_funcs(&lcm_utils); //这个没什么用处
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lcm->get_params(lcm_params); //调用nt35516的lcm_get_params,获取参数
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if(lcm_count == 1)
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{
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lcm_drv = lcm; //找到lcm的驱动结构体之后就保存在全局变量lcm_drv中
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isLCMFound = TRUE; //标志isLCMFound设为true
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break;
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}
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}
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switch(lcm_params->type)
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{
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//将驱动的函数指针的保存在disp_drv中
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case LCM_TYPE_DBI : disp_drv = DISP_GetDriverDBI(); break;
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case LCM_TYPE_DPI : disp_drv = DISP_GetDriverDPI(); break;
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case LCM_TYPE_DSI : disp_drv = DISP_GetDriverDSI(); break; //这儿用的是这个
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default : ASSERT(0);
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}
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return TRUE;
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}
3.2 获取FB_SIZE
DISP_GetVRamSizeBoot
--> DISP_GetVRamSize
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UINT32 DISP_GetVRamSize(void)
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{
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static UINT32 vramSize = 0;
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if (0 == vramSize)
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{
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disp_drv_init_context();
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//获取fb_size=w*h*bpp/8*2=960*544*4*2=4177920
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vramSize = DISP_GetFBRamSize();
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///get DXI working buffer size=0
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vramSize += disp_drv->get_working_buffer_size();
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//layerSize=w*h*2+4096=960*540*2+4096, total=5218816
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vramSize += DAL_GetLayerSize();
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//对齐到1M, 0x500000=5M
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vramSize = ALIGN_TO_POW_OF_2(vramSize, 0x100000);
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}
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return vramSize;
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}
二. fb驱动
在alps/kernel/mediatek/source/kernel/drivers/video/mtkfb.c中
module_init(mtkfb_init);
--> platform_driver_register(&mtkfb_driver)
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#define MTKFB_DRIVER "mtkfb"
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static struct platform_driver mtkfb_driver =
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{
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.driver = {
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.name = MTKFB_DRIVER, //驱动的name="mtkfb"正好与设备匹配,调用probe
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.bus = &platform_bus_type,
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.probe = mtkfb_probe,
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.remove = mtkfb_remove,
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.suspend = mtkfb_suspend,
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.resume = mtkfb_resume,
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.shutdown = mtkfb_shutdown,
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},
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};
1. 驱动的probe函数
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static int mtkfb_probe(struct device *dev)
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{
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struct platform_device *pdev;
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struct mtkfb_device *fbdev = NULL;
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struct fb_info *fbi;
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a.从uboot传给kernel的命令行字符串中解析出fps
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//console=ttyMT0,921600n1 root=/dev/ram vmalloc=280M slub_max_order=0
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//uboot_ver=2010.06 uboot_build_ver=MAIN2.2.ubt.4158 lcm=1-nt35516_3d fps=6004
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lcd_fps = simple_strtol(p, NULL, 10); //lcd_fps=6004
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if(DISP_IsContextInited() == FALSE) //在FB_SIZE宏中己经初始化过了,进入else
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{
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mtkfb_find_lcm_driver();
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}
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else
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{
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LCD_CHECK_RET(LCD_Init()); //1.1 硬件初始化并申请中断和等侍队列
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}
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//初始化下面这6个全局变量
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MTK_FB_XRES = DISP_GetScreenWidth();
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MTK_FB_YRES = DISP_GetScreenHeight();
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fb_xres_update = MTK_FB_XRES;
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fb_yres_update = MTK_FB_YRES;
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MTK_FB_BPP = DISP_GetScreenBpp();
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MTK_FB_PAGES = DISP_GetPages();
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init_waitqueue_head(&screen_update_wq); //又一个等侍队列
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//创建线程并唤醒, kthread_create之后并不会马上运行,需要wake_up
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screen_update_task = kthread_create(screen_update_kthread, NULL, "screen_update_kthread");
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wake_up_process(screen_update_task);
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//注册两个回调函数
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DISP_INTERRUPT_CALLBACK_STRUCT cbStruct;
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cbStruct.pFunc = mtkfb_lcd_complete_interrupt;
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cbStruct.pParam = NULL;
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DISP_SetInterruptCallback(DISP_LCD_TRANSFER_COMPLETE_INT, &cbStruct);
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DISP_INTERRUPT_CALLBACK_STRUCT cbStruct;
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cbStruct.pFunc = mtkfb_dpi_vsync_interrupt;
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cbStruct.pParam = NULL;
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DISP_SetInterruptCallback(DISP_DPI_VSYNC_INT, &cbStruct);
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init_state = 0;
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pdev = to_platform_device(dev);
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//申请framebuffer
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fbi = framebuffer_alloc(sizeof(struct mtkfb_device), dev);
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mtkfb_fbi = fbi;
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fbdev = (struct mtkfb_device *)fbi->par;
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fbdev->fb_info = fbi;
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fbdev->dev = dev;
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dev_set_drvdata(dev, fbdev);
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init_state++;
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fbdev->fb_size_in_byte = MTK_FB_SIZEV;
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struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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fbdev->fb_pa_base = res->start; //获取fb的物理地址,并映射
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fbdev->fb_va_base = ioremap_nocache(res->start, res->end - res->start + 1);
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#if defined(MTK_M4U_SUPPORT)
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fb_va_m4u = fbdev->fb_pa_base;
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fb_size_m4u = fbdev->fb_size_in_byte;
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//为overlay的链表分配内存
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overlay_buffer_head = (struct fb_overlay_buffer_list*)vmalloc(sizeof(struct fb_overlay_buffer_list));
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overlay_buffer_head->next = NULL;
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#endif
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init_state++; // 2
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DISP_Init((DWORD)fbdev->fb_va_base, (DWORD)fbdev->fb_pa_base, is_lcm_inited);
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init_state++; // 3
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r = mtkfb_fbinfo_init(fbi); //初始化 fb_info
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init_state++; // 4
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r = mtkfb_register_sysfs(fbdev);
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init_state++; // 5
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r = register_framebuffer(fbi); //注册
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fbdev->state = MTKFB_ACTIVE;
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return 0;
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}
1.1 硬件初始化并申请中断+初始化等侍队列
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LCD_STATUS LCD_Init(void)
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{
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memset(&_lcdContext, 0, sizeof(_lcdContext));
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_ResetBackupedLCDRegisterValues();
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ret = LCD_PowerOn();
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LCD_OUTREG32(&LCD_REG->SYNC_LCM_SIZE, 0x00010001);
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LCD_OUTREG32(&LCD_REG->SYNC_CNT, 0x1);
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//申请中断和等侍队列
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request_irq(MT6577_LCD_IRQ_ID, _LCD_InterruptHandler, IRQF_TRIGGER_LOW, "mtklcd", NULL);
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init_waitqueue_head(&_lcd_wait_queue);
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LCD_REG->INT_ENABLE.COMPLETED = 1;
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LCD_REG->INT_ENABLE.CMDQ_COMPLETED = 1;
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LCD_REG->INT_ENABLE.HTT = 1;
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LCD_REG->INT_ENABLE.SYNC = 1;
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return LCD_STATUS_OK;
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}
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static irqreturn_t _LCD_InterruptHandler(int irq, void *dev_id)
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{
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LCD_REG_INTERRUPT status = LCD_REG->INT_STATUS;
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if (status.COMPLETED)
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{
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wake_up_interruptible(&_lcd_wait_queue);
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//即调用mtkfb_lcd_complete_interrupt
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if(_lcdContext.pIntCallback)
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_lcdContext.pIntCallback(DISP_LCD_TRANSFER_COMPLETE_INT);
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}
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if (status.SYNC)
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{
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//DISP_LCD_SYNC_INT即调用mtkfb_lcd_complete_interrupt
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if(_lcdContext.pIntCallback)
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_lcdContext.pIntCallback(DISP_LCD_SYNC_INT);
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lcd_esd_check = false;
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}
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LCD_OUTREG32(&LCD_REG->INT_STATUS, 0);
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return IRQ_HANDLED;
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}
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static void mtkfb_lcd_complete_interrupt(void *param)
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{
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if(atomic_read(&has_pending_update))
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{
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wake_up_interruptible(&screen_update_wq);
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}
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#if defined(MTK_HDMI_SUPPORT)
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hdmi_source_buffer_switch();
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if(is_hdmi_active())
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{
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hdmi_update();
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}
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#endif
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}
线程函数中wait_event
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static int screen_update_kthread(void *data)
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{
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struct sched_param param = { .sched_priority = RTPM_PRIO_SCRN_UPDATE };
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sched_setscheduler(current, SCHED_RR, ¶m);
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for( ;; ) {
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wait_event_interruptible(screen_update_wq, atomic_read(&has_pending_update));
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MTKFB_LOG("wq wakeup\n");
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mtkfb_update_screen_impl();
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atomic_set(&has_pending_update,0);
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if (kthread_should_stop())
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break;
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}
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return 0;
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}
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