topic i-MX8MP uboot支持 dual LVDS(1920*1080)显示吗？我们现在在i-MX8MPkernel点亮了 dual lvds,但是kernel 没有显示logo in i.MX Processors

i-MX8MP uboot支持 dual LVDS(1920*1080)显示吗？我们现在在i-MX8MPkernel点亮了 dual lvds,但是kernel 没有显示logo

xierong — Sun, 08 Oct 2023 09:30:16 GMT

uboot 已经添加单lvds 显示 patch

[*]-Video Link 0 [*]-Video Link 0imx8mp_ldb_probe innnnnnnnimx8mp_ldb_probe innnnnnnn 1imx8mp_ldb_probe okkkkkk
imx8mp_ldb_probe innnnnnnnimx8mp_ldb_probe innnnnnnn 2imx8mp_ldb_probe innnnnnnn 3imx8mp_ldb_probe okkkkkk
lcdifv3_video_probe000
imx8mp_lvds_phy_init innnnnnnnimx8mp_lvds_phy_power_on innnnnnnnimx8mp_ldb_enable okkkkkk
imx8mp_ldb_enable okkkkkk
lcdifv3_set_bus_fmt innnnnnnn disp_para = 0 oklcdifv3_set_bus_fmt innnnnnnn disp_para = 0 2ok (1920 x 1080)
[0] lcd-controller@32e90000, video
[1] lvds-channel@0, display
[2] lvds-channel@0, display

能够检测到设置的分辨率 (1920 x 1080)

Re: i-MX8MP uboot支持 dual LVDS(1920*1080)显示吗？我们现在在i-MX8MPkernel点亮了 dual lvds,但是kernel 没有显示logo

Zhiming_Liu — Mon, 09 Oct 2023 02:14:34 GMT

1.那个补丁里只打开了CH0，如果你需要双通道，修改驱动中写入LVDS_CTRL寄存器中的值就可以。

2.时钟设置部分需要修改。

3.对于内核显示,请参考arch/arm64/boot/dts/freescale/imx8mp-evk-jdi-wuxga-lvds-panel.dts，并检查像素格式是否正确。

fsl,data-mapping = "spwg"; fsl,data-width = <24>;

此外，需要添加新的PLL值来让内核获得正确的时钟，对于双通道，PLL值应当为pixel clock*7。PLL参数参考手册里的公式。

static const struct imx_pll14xx_rate_table imx_pll1443x_tbl[] = { PLL_1443X_RATE(1039500000U, 173, 2, 1, 16384), PLL_1443X_RATE(650000000U, 325, 3, 2, 0), PLL_1443X_RATE(594000000U, 198, 2, 2, 0), PLL_1443X_RATE(519750000U, 173, 2, 2, 16384), PLL_1443X_RATE(393216000U, 262, 2, 3, 9437), PLL_1443X_RATE(361267200U, 361, 3, 3, 17511), };

Re: i-MX8MP uboot支持 dual LVDS(1920*1080)显示吗？我们现在在i-MX8MPkernel点亮了 dual lvds,但是kernel 没有显示logo

xierong — Tue, 10 Oct 2023 08:51:52 GMT

你好，我这两天尝试uboot 修改imx8mp_lvds.c 支持CH1，测量时钟还有信号线都是正常的，

media_blk_write(priv, LDB_CTRL, LDB_CH1_MODE_EN_TO_DI0 | LDB_DATA_WIDTH_CH1_24 | LDB_BIT_MAP_CH1_SPWG);

时钟添加

static const struct imx_pll14xx_rate_table imx_pll1443x_tbl[] = {

PLL_1443X_RATE(1039500000U, 173, 2, 1, 16384),

+ PLL_1443X_RATE(945000000U, 325, 3, 2, 0), //135 000000*7

PLL_1443X_RATE(650000000U, 325, 3, 2, 0),

PLL_1443X_RATE(594000000U, 198, 2, 2, 0),

PLL_1443X_RATE(519750000U, 173, 2, 2, 16384),

PLL_1443X_RATE(393216000U, 262, 2, 3, 9437),

PLL_1443X_RATE(361267200U, 361, 3, 3, 17511),

};

也还没能够显示logo

打印如下

imx8mp_ldb_bind in
imx8mp_ldb_bind in
get binding driver name 'imx8mp_ldb'
get binding driver name 'imx8mp_ldb'
MMC: FSL_SDHC: 1, FSL_SDHC: 2
Loading Environment from MMC... *** Warning - bad CRC, using default environment

video link number: 1 curr_video_link: 0
[*]-Video Link 0
in video_link_get_video_device
imx8mp_ldb_probe
imx8mp_ldb_probe enable_gpio ok set 1
imx8mp_ldb_probe innnnnnnn 1
imx8mp_ldb_probe okkkkkk
imx8mp_ldb_probe
imx8mp_ldb_probe: Warning: cannot get enable GPIO: ret=-2
imx8mp_ldb_probe enable_gpio ok set 1
imx8mp_ldb_probe innnnnnnn 2
in video_link_get_display_timings
in video_link_get_display_timings 1
in video_link_get_display_timings 3

in ofnode_decode_display_timing hback_porch -1125010276 -1125010288 -1125010300 -1125010264 121
ldb probe in video_link_get_display_timings
imx8mp_ldb_probe innnnnnnn 3
imx8mp_ldb_probe innnnnnnn 4
imx8mp_ldb_probe okkkkkk
in video_link_get_display_timings
in video_link_get_display_timings 1
in video_link_get_display_timings 3

in ofnode_decode_display_timing hback_porch -1125138788 -1125138800 -1125138812 -1125138776 121
lcdifv3_video_probe000
imx8mp_lvds_phy_power_on
imx8mp_ldb_enable okkkkkk
imx8mp_ldb_enable okkkkkk
lcdifv3_set_bus_fmt innnnnnnn disp_para = 0 2ok
in video_link_get_video_device ok
video_link (1920 x 1080)

video_link [0] lcd-controller@32e90000, video
video_link [1] lvds-channel@0, display
video_link [2] lvds-channel@0, display
in video_link_get_video_device
in video_link_get_video_device ok

请问哪里还有没修改对的呢

Re: i-MX8MP uboot支持 dual LVDS(1920*1080)显示吗？我们现在在i-MX8MPkernel点亮了 dual lvds,但是kernel 没有显示logo

Zhiming_Liu — Mon, 16 Oct 2023 03:03:09 GMT

你需要用手册里的PLL计算公式得到正确的PMKS 参数，650M和945M的PMKS参数咋能一样？