imx6 RGB LCD
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
