imx6 hdmi接口支持

/*************************************************************
 *                    imx6 hdmi接口支持
 *    新的板子需要使用到hdmi,今天就测试一下。
 *      参考链接：
 *        I.MX6 lcd lvds hdmi bootargs:
 *            http://www.cnblogs.com/zengjfgit/p/5139546.html
 *        hdmi问题：
 *            https://community.freescale.com/thread/366072
 *
 *                                    Tony, 2016-5-20, Shenzhen
**************************************************************/
1、按照参考链接更改uboot/include/configs/mx6dl_sabresd_android.h
#define CONFIG_INITRD_TAG
#define    CONFIG_EXTRA_ENV_SETTINGS                    \
                "netdev=eth0\0"                                         \
                "ethprime=FEC0\0"                                       \
                "uboot=u-boot.bin\0"                    \
                "kernel=uImage\0"                               \
                "nfsroot=/opt/eldk/arm\0"                               \
                "bootargs_base=setenv bootargs console=ttymxc0,115200\0"\
                "bootargs_nfs=setenv bootargs ${bootargs} root=/dev/nfs "\
                        "ip=dhcp nfsroot=${serverip}:${nfsroot},v3,tcp\0"\
                "bootcmd_net=run bootargs_base bootargs_nfs; "          \
                        "tftpboot ${loadaddr} ${kernel}; bootm\0"       \
                "bootargs_mmc=setenv bootargs ${bootargs} ip=none "     \
                        "root=/dev/mmcblk0p1 rootwait\0"                \
                "bootcmd_mmc=run bootargs_base bootargs_mmc; "   \
                "mmc dev 2; "   \
                "mmc read ${loadaddr} 0x800 0x3000; bootm\0"    \
                "bootcmd=run bootcmd_mmc\0"                             \
                "bootargs=console=ttymxc0,115200 init=/init video=mxcfb0:off video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24,bpp=32 video=mxcfb2:off ldb=dul1 fbmem=10M,30M vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0" \
                "splashimage=0x30000000\0"                \
                "splashpos=m,m\0"                    \
                "lvds_num=1\0"
#endif
2.
更改uboot参数之后，并没有生效.
原因是bootargs采用了默认的参数。
bootcmd = run bootcmd_mmc
bootcmd_mmc = run bootargs_base bootargs_mmc
在run bootargs_base 之后就不运行run bootargs_mmc
更改   "bootcmd_mmc=run bootargs_base bootargs_mmc; "
如下：
　　　　"bootcmd_mmc=run bootargs_mmc; "  

qt版本的目前不能同时支持2个屏，只能支持一种屏。qt只能支持配置一个framebuffer,参考/etc/profile.
配置成功之后,kernel输出：
Uncompressing Linux... done, booting the kernel.
......
Kernel command line: console=ttymxc0, init=/init video=mxcfb0:off video=mxcfb1:dev=hdmi,1920x1080M@,if=RGB24,bpp= video=mxcfb2:off ldb=dul1 fbmem=10M,30M vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale ip=none root=/dev/mmcblk0p1 rootwait
......

3.问题
hdmi其中之后, 在串口一直输出：
mxc_hdmi mxc_hdmi: same edid
mxc_hdmi mxc_hdmi: same edid
mxc_hdmi mxc_hdmi: same edid
mxc_hdmi mxc_hdmi: same edid
根据参考链接得知，HDMI的线没有插好。