imx6 RGB LCD

时间：2024-04-05 09:03:52

imx6dl需要支持lcd接口的屏，imx6dl的datasheet并没有明确的说明lcd相关的配置，只在Display Content Integrity Checker (DCIC)一章中介绍。本文记录imx6支持lcd的方法。

参考链接

http://developer.toradex.com/knowledge-base/display-output-resolution-and-timings-linux

https://community.nxp.com/thread/307613

http://cache.freescale.com/files/32bit/doc/user_guide/MX53UG.pdf

https://boundarydevices.com/configuring-i-mx6-machines-different-screens-nitrogen6x-sabre-lite/

uboot

更改bootargs，添加lcd支持：video=mxcfb0:dev=lcd,SEIKO-WVGA,if=RGB24,bpp=32

include/configs/mx6dl_sabresd_android.h

#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 video=mxcfb0:dev=lcd,SEIKO-WVGA,if=RGB24,bpp=32\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 "   \

        "splashimage=0x30000000\0"              \

        "splashpos=m,m\0"                   \

        "lvds_num=1\0"

kernel

需要注册设备和驱动

device

配置引脚复用

arch/arm/mach-mx6/board-mx6dl_sabresd.h

static iomux_v3_cfg_t mx6dl_sabresd_pads[] = {

    ......

    MX6DL_PAD_DI0_DISP_CLK__IPU1_DI0_DISP_CLK,

    MX6DL_PAD_DI0_PIN15__IPU1_DI0_PIN15,        /* DE */

    MX6DL_PAD_DI0_PIN2__IPU1_DI0_PIN2,          /* HSync */

    MX6DL_PAD_DI0_PIN3__IPU1_DI0_PIN3,          /* VSync */

    MX6DL_PAD_DI0_PIN4__IPU1_DI0_PIN4,          /* Contrast */

    MX6DL_PAD_DISP0_DAT0__IPU1_DISP0_DAT_0,

    MX6DL_PAD_DISP0_DAT1__IPU1_DISP0_DAT_1,

    MX6DL_PAD_DISP0_DAT2__IPU1_DISP0_DAT_2,

    MX6DL_PAD_DISP0_DAT3__IPU1_DISP0_DAT_3,

    MX6DL_PAD_DISP0_DAT4__IPU1_DISP0_DAT_4,

    MX6DL_PAD_DISP0_DAT5__IPU1_DISP0_DAT_5,

    MX6DL_PAD_DISP0_DAT6__IPU1_DISP0_DAT_6,

    MX6DL_PAD_DISP0_DAT7__IPU1_DISP0_DAT_7,

    MX6DL_PAD_DISP0_DAT8__IPU1_DISP0_DAT_8,

    MX6DL_PAD_DISP0_DAT9__IPU1_DISP0_DAT_9,

    MX6DL_PAD_DISP0_DAT10__IPU1_DISP0_DAT_10,

    MX6DL_PAD_DISP0_DAT11__IPU1_DISP0_DAT_11,

    MX6DL_PAD_DISP0_DAT12__IPU1_DISP0_DAT_12,

    MX6DL_PAD_DISP0_DAT13__IPU1_DISP0_DAT_13,

    MX6DL_PAD_DISP0_DAT14__IPU1_DISP0_DAT_14,

    MX6DL_PAD_DISP0_DAT15__IPU1_DISP0_DAT_15,

    MX6DL_PAD_DISP0_DAT16__IPU1_DISP0_DAT_16,

    MX6DL_PAD_DISP0_DAT17__IPU1_DISP0_DAT_17,

    MX6DL_PAD_DISP0_DAT18__IPU1_DISP0_DAT_18,

    MX6DL_PAD_DISP0_DAT19__IPU1_DISP0_DAT_19,

    MX6DL_PAD_DISP0_DAT20__IPU1_DISP0_DAT_20,

    MX6DL_PAD_DISP0_DAT21__IPU1_DISP0_DAT_21,

    MX6DL_PAD_DISP0_DAT22__IPU1_DISP0_DAT_22,

    MX6DL_PAD_DISP0_DAT23__IPU1_DISP0_DAT_23,

    ......

};

设备初始化

arch/arm/mach-mx6/board-mx6q_sabresd.c

// 与bootargs中"dev=lcd,SEIKO-WVGA" 对应

static struct ipuv3_fb_platform_data sabresd_fb_data[] = {

    // Tony 2016-11-22

    {

    .disp_dev = "lcd",

    .interface_pix_fmt = IPU_PIX_FMT_RGB24,

    .mode_str = "SEIKO-WVGA",

    .default_bpp = 32,

    .int_clk = false,

    },

    { /*fb0*/

    .disp_dev = "ldb",

    .interface_pix_fmt = IPU_PIX_FMT_RGB24,

    .mode_str = "LDB-XGA",

    //.default_bpp = 16,

    .default_bpp = 24,

    .int_clk = false,

    .late_init = false,

    }, {

    .disp_dev = "hdmi",

    .interface_pix_fmt = IPU_PIX_FMT_RGB24,

    .mode_str = "1920x1080M@60",

    .default_bpp = 32,

    .int_clk = false,

    .late_init = false,

    }, {

};

static struct fsl_mxc_lcd_platform_data lcdif_data = {

    .ipu_id = 0,		// ipu 0

    .disp_id = 0,		// 第0个接口

    .default_ifmt = IPU_PIX_FMT_RGB24,

};

// lcd初始化

static void __init mx6_sabresd_board_init(void)

{

	......

	imx6q_add_ipuv3(0, &ipu_data[0]);

    if (cpu_is_mx6q()) {

        imx6q_add_ipuv3(1, &ipu_data[1]);

        for (i = 0; i < 4 && i < ARRAY_SIZE(sabresd_fb_data); i++)

            imx6q_add_ipuv3fb(i, &sabresd_fb_data[i]);

    } else

        for (i = 0; i < 2 && i < ARRAY_SIZE(sabresd_fb_data); i++) //不知道这里为什么要i<2,难道因为imx6的ipu只有2个接口？

            imx6q_add_ipuv3fb(i, &sabresd_fb_data[i]);

    imx6q_add_lcdif(&lcdif_data);

	......

}

driver

添加lcd的驱动支持

make menuconfig

选择 SEIKO WVGA Panel

Prompt: SEIKO WVGA Panel

     Defined at drivers/video/mxc/Kconfig:55

     Depends on: HAS_IOMEM [=y] && ARCH_MXC [=y] && FB_MXC_SYNC_PANEL [=y]

     Location:

       -> Device Drivers

         -> Graphics support

           -> MXC Framebuffer support (FB_MXC [=y])

             -> Synchronous Panel Framebuffer (FB_MXC_SYNC_PANEL [=y])

更改LCD参数。

drivers/video/mxc/mxc_lcdif.c

static struct fb_videomode lcdif_modedb[] = {

	...

	{

    /* 640x480 @ 60 Hz , pixel clk @ 25MHz */

    "SEIKO-WVGA", 60, 640, 480, 40000, 89, 164, 23, 10, 10, 10,

    FB_SYNC_CLK_LAT_FALL,

    FB_VMODE_NONINTERLACED,

    0,},

	...

};

Tony Liu

2016-11-28, Shenzhen

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