imx6 android4.3 bsp开发实录之一lvds、HDMMI输出显示

手上有多块屏 LVDS双通道， LVDS单通道， HDMI1980P，怎么说了，这个私活真的有点坑的，不过还好，做起来也容易

案例一   LVDS单通道

相信看过freescale驱动源码的都知道，显示这块支持好几种模式，下面贴一下代码

mxc_ipuv3_fb.c   freescale GPU驱动文件

路径myandroid/kernel_imx/drivers/video/mxc/ldb.c里

/*
 *    "ldb=spl0/1"       --      split mode on DI0/1
 *    "ldb=dul0/1"       --      dual mode on DI0/1
 *    "ldb=sin0/1"       --      single mode on LVDS0/1
 *    "ldb=sep0/1"       --      separate mode begin from LVDS0/1
 *
 *    there are two LVDS channels(LVDS0 and LVDS1) which can transfer video
 *    datas, there two channels can be used as split/dual/single/separate mode.
 *
 *    split mode means display data from DI0 or DI1 will send to both channels
 *    LVDS0+LVDS1.
 *    dual mode means display data from DI0 or DI1 will be duplicated on LVDS0
 *    and LVDS1, it said, LVDS0 and LVDS1 has the same content.
 *    single mode means only work for DI0/DI1->LVDS0 or DI0/DI1->LVDS1.
 *    separate mode means you can make DI0/DI1->LVDS0 and DI0/DI1->LVDS1 work
 *    at the same time.
 */

好了，看了上面的支持的模式，对照手里的两块单通道和双通道的屏，还是一头雾水啊，找到了这个，可是分辨率怎么调整呢，没事我们一步一步来

接下来是要看一个结构体，相信大家都不陌生，在 myandroid/kernel_imx/include/linux/fb.h里有定义

struct fb_videomode {
        const char *name;       /* optional */
        u32 refresh;            /* optional */
        u32 xres;
        u32 yres;
        u32 pixclock;
        u32 left_margin;
        u32 right_margin;
        u32 upper_margin;
        u32 lower_margin;
        u32 hsync_len;
        u32 vsync_len;
        u32 sync;
        u32 vmode;
        u32 flag;
};

好了，我们根据具体的屏的参数将其对应的修改，

我这里单通道的屏分辨率是1024*768分辨率M121GNX2 R1

   {
        "LDB-1024P768", 60, 1024, 768, 15384,
        100, 100,
        12, 12,
        120, 14,
        FB_VMODE_NONINTERLACED,
        FB_MODE_IS_DETAILED,
        },

双通道的分辨率是1440*900  M190PW01 V8

 {
         "LDB-WXGA", 60, 1440, 900, 18868,
         160, 160,
         12, 10,
         168, 10,
         FB_SYNC_EXT,
         FB_VMODE_NONINTERLACED,
         0,},
        {
         "LDB-XGA", 60, 1440, 900, 18501,
         220, 40,
         21, 7,
         60, 10,
         FB_SYNC_EXT,
         FB_VMODE_NONINTERLACED,
         0,},
        {
         "LDB-1080P60", 60, 1440, 900, 18868,
         160, 160,
         12, 10,
         168, 10,
         FB_SYNC_EXT,
         FB_VMODE_NONINTERLACED,
         0,},

修改完以上的参数，剩下的就是要修改我们uboot启动时候传递的参数了，这个相信大家比我还熟悉，我就不用明说了


单通道显示的参数

U-Boot > setenv bootargs console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,LDB-1024PP768,if=RGB18 ldb=sin0 video=mxcfb1:off video=mxcfb2:off fbmem=10M fb0base=0x27b00000 vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale

双通道显示的参数

U-Boot > setenv bootargs console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,LDB-XGA,if=RGB24 ldb=spl0 video=mxcfb1:off video=mxcfb2:off fbmem=10M fb0base=0x27b00000 vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale

以上是LVDS的修改，接下来我们说一下HDMI的1080p的调试

其实方法差不多

 /* #16: 1920x1080p@60Hz 16:9 */
    100         [16] = {
    101                 NULL, 60, 1920, 1080, 6734, 148, 88, 36, 4, 44, 5,
    102                 FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
    103                 FB_VMODE_NONINTERLACED | FB_VMODE_ASPECT_16_9, 0,
    104         },

U-Boot > setenv bootargs console=ttymxc0,115200 init=/init rw video=mxcfb0:dev=hdmi,1920x1080@60,bpp=25 video=mxcfb1:off video=mxcfb2:off fbmem=10M,28M vmalloc=512M androidboot.console=ttymxc0 androidboot.hardware=freescale

U-Boot > setenv bootargs console=ttymxc0,115200 init=/init rw video=mxcfb0:dev=hdmi,1920x1080@60,if=RGB32,bpp=32 video=mxcfb1:off video=mxcfb2:off fbmem=40M,68M vmalloc=512M androidboot.console=ttymxc0 androidboot.hardware=freescale