A133适配AMOLED屏幕，LCD时序参数过小导致无法进入U-Boot

ceoifung LV 4

目前有一个LCD驱动，里面的LCD时序参数是：

lcd_hbp             = <40>;
lcd_ht              = <820>;
lcd_hspw            = <20>;
lcd_vbp             = <16>;
lcd_vt              = <1320>;
lcd_vspw            = <8>;

然后能正常进入U-Boot，但是新屏幕，我修改了如下参数：

lcd_hbp             = <20>;
lcd_ht              = <654>;
lcd_hspw            = <32>;
lcd_vbp             = <12>;
lcd_vt              = <828>;
lcd_vspw            = <4>;

然后就发现U-Boot进不去了，然后我适当增大了lcd_hbp、lcd_vbp的值，然后就能进入U-Boot了，修改后的参数是：

lcd_hbp             = <40>;
lcd_ht              = <684>;
lcd_hspw            = <32>;
lcd_vbp             = <16>;
lcd_vt              = <888>;
lcd_vspw            = <4>;

所以我现在的疑问是LCD时序参数里面lcd_hbp与lcd_vbp是不是有一个最小值限制呀？另外屏厂给的推荐参数就是那个不能进入U-Boot的参数值，适当增大之后对屏幕驱动是不是有相关影响呀？求各位大佬帮帮忙

anruliu LV 6

@ceoifung 看这个
@anruliu 在 D1H支持1920*1200分辨率，但是1080*1920竖屏支持吗中说：

@xiaoxiao

你是怎么互换的，如果计算出现负数肯定进不去

lcd_x = 屏厂给的实际的x
lcd_hbp = 屏厂给的实际的hbp + 屏厂给的实际的hsync
lcd_ht = 屏厂给的实际的lcd_h + 屏厂给的实际的hsync + 屏厂给的实际的hbp + 屏厂给的实际的hfp
lcd_hspw = 屏厂给的实际的hsync

lcd_y = 屏厂给的实际的y
lcd_vpp = 屏厂给的实际的vbp + 屏厂给的实际的vsync
lcd_vt = 屏厂给的实际的lcd_y + 屏厂给的实际的vsync + 屏厂给的实际的vbp + 屏厂给的实际的vfp
lcd_vspw = 屏厂给的实际的vsync

ceoifung LV 4

@anruliu 我这边重新计算了以下相关的值，还是进不去u-boot，我的屏幕13.3寸，这个和屏幕大小尺寸会有关系吗？以下是开机后，打印的内容

[SCP] :sunxi-arisc driver begin startup 2
[SCP] :0x1
[SCP] :arisc version: []
[SCP] :arisc startup ready
[SCP] :arisc startup notify message feedback
[SCP] :send hard sync feedback message: 0x900200
[SCP] :sunxi-arisc driver v1.10 is starting
[00.616]PMU: AXP803
[00.618]PMU: AXP803
bias_name:pc_bias        bias_vol:1800
[00.688]CPU=1008 MHz,PLL6=600 Mhz,AHB=200 Mhz, APB1=100Mhz  MBus=400Mhz
[00.695]drv_disp_init
[00.720]drv_disp_init finish
[00.726]gic: sec monitor mode
[00.728]flash init start
[00.730]workmode = 0,storage type = 2
[00.734][mmc]: mmc driver ver uboot2018:2020-5-25 9:26:00-202007011433
[00.741][mmc]: get sdc_type fail and use default host:tm4.
[00.753][mmc]: SUNXI SDMMC Controller Version:0x50300
[00.781][mmc]: Best spd md: 4-HS400, freq: 3-100000000, Bus width: 8
[00.787]sunxi flash init ok
[00.791]Loading Environment from SUNXI_FLASH... OK
[00.800]out of usb burn from boot: not need burn key
[00.804]boot_gui_init:start
[00.809]set disp.dev2_output_type fail. using defval=0

串口输出到[00.809]set disp.dev2_output_type fail. using defval=0就没有内容了，然后测试发现初始化完LCD_cfg_panel_info这个函数之后，进不去LCD_power_on这个函数

anruliu LV 6

@ceoifung 贴出你的dts lcd0部分

WhycanService LV 8

lcd_x = 屏厂给的实际的x
lcd_hbp = 屏厂给的实际的hbp + 屏厂给的实际的hsync
lcd_ht = 屏厂给的实际的lcd_h + 屏厂给的实际的hsync + 屏厂给的实际的hbp + 屏厂给的实际的hfp
lcd_hspw = 屏厂给的实际的hsync

lcd_y = 屏厂给的实际的y
lcd_vbp = 屏厂给的实际的vbp + 屏厂给的实际的vsync
lcd_vt = 屏厂给的实际的lcd_y + 屏厂给的实际的vsync + 屏厂给的实际的vbp + 屏厂给的实际的vfp
lcd_vspw = 屏厂给的实际的vsync

驱动会通过上面的参数计算lcd_xbp与lcd_xspw的值来确定实际的屏幕的参数（实际的vsync，实际的vbp等等），当给的值不对计算出现负数的时候会卡死不启动。

ceoifung LV 4

@anruliu

lcd0: lcd0@01c0c000 {
			lcd_used            = <1>;

			lcd_driver_name     = "xiaor_amoled";
			lcd_backlight       = <255>;
			lcd_if              = <4>;

			lcd_x               = <600>;
			lcd_y               = <800>;
			lcd_width           = <190>;
			lcd_height          = <254>;
			lcd_dclk_freq       = <55>;

			lcd_pwm_used        = <0>;
			lcd_pwm_ch          = <0>;
			lcd_pwm_freq        = <5000>;
			lcd_pwm_pol         = <1>;
			lcd_pwm_max_limit   = <250>;

			lcd_hbp             = <52>;
			lcd_ht              = <654>;
			lcd_hspw            = <32>;
			lcd_vbp             = <16>;
			lcd_vt              = <828>;
			lcd_vspw            = <4>;

			lcd_frm             = <0>;
			lcd_io_phase		= <0>;
			lcd_gamma_en        = <0>;
			lcd_bright_curve_en = <0>;
			lcd_cmap_en         = <0>;
			
			deu_mode            = <0>;
			lcdgamma4iep        = <22>;
			smart_color         = <90>;

			lcd_dsi_if          = <0>;
			lcd_dsi_lane        = <4>;
			lcd_dsi_format      = <0>;
			lcd_dsi_te          = <0>;
			lcd_dsi_eotp        = <0>;

			lcd_pin_power = "eldo1";
			lcd_power = "dc1sw";
			//lcd_bl_en = <&pio PG 9 1 0 3 1>;
			lcd_gpio_0 = <&pio PB 6 1 1 3 1>;
			lcd_gpio_1 = <&pio PB 2 1 1 3 1>;
			lcd_gpio_2 = <&pio PD 20 1 1 3 1>;
			pinctrl-0 = <&dsi4lane_pins_a>;
			pinctrl-1 = <&dsi4lane_pins_b>;
		};

anruliu LV 6

@ceoifung hfp = 654-600-52=2，屏厂给的hfp怎么这么小

ceoifung LV 4

@anruliu 屏厂给的这个参数就是这么小的

ceoifung LV 4

@anruliu 请问一下：屏厂给的参数就是这样的，对方FAE说这个参数可能不适用于所有的平台，需要芯片厂家推荐一个合适的值，下面是厂商给的部分参数，A133这个平台LCD的时序与这个屏幕怎么个调整比较合适呢？大佬有什么解决方法吗？

建议值：HSW=32，HBP=20，HFP=2， VSW=4，VBP=12，VFP=12
分辨率：720*800
Frame rate：60HZ

anruliu LV 6

@ceoifung

lcd_dclk_freq = <38>;
lcd_x = <720>;
lcd_y = <800>;

lcd_hbp = <52>;
lcd_ht = <774>;
lcd_hspw = <32>;
lcd_vbp = <16>;
lcd_vt = <828>;
lcd_vspw = <4>;

不行的话，lcd_ht以2为挡位慢慢网上加试试