一.简介
龙讯LT9211是一个高性能转换器，支持MIPI LVDS TTL两两之间转换。
使用此款芯片大部分为MIPI与LVDS进行互相转换。
下图为LT9211的典型应用图：
二.LT9211原理图
三.车载显示器和摄像头系统
四.调试LT9211输出 MIPI数据
（1）insmod加载ko文件后，ls /dev 查看是否生成新的video节点。
->如果没有生成video节点，查看ko是否加载失败，dts配置是否正确。
（2）查看设备是否成功挂载在IIC上
->i2cdetect -r -y 5 (lt9211在iic1上地址为ox2b)。
（3）查看LT9211_ChipID寄存器值
void LT9211_ChipID(void)
{lt8918_write_reg(0xff,0x81);//register bankpr_info("\r\nLT9211 Chip ID:%x,",lt8918_read_reg(0x00));//18pr_info("%x, ",lt8918_read_reg(0x01));//1pr_info("%x, ",lt8918_read_reg(0x02));//e4
}(4)检查LT9211打印log
hfp,hbp,hsync,vfp,vbp,vysnc输出正确。
（5）测量mipi信号
MIPI data ：1.8V的方波。
图像数据在soc mipi接收过程是需要检测到各个lane的LP11-LP10-LP00的一个状态切换后才会切换
到高速模式准备接收。
（6）确认mipi lane数与硬件连接的是否一致。
五.LT9211MCU程序
/******************************************************************************* @project: LT9211* @file: lt9211.c* @author: zll* @company: LONTIUM COPYRIGHT and CONFIDENTIAL* @date: 2019.04.10
/******************************************************************************/#include "include.h"u16 hact, vact;
u16 hs, vs;
u16 hbp, vbp;
u16 htotal, vtotal;
u16 hfp, vfp;
u8 VideoFormat=0;
u32 lvds_clk_in = 0;#define OFFSET 5struct video_timing *pVideo_Format;//hfp, hs, hbp, hact, htotal, vfp, vs, vbp, vact, vtotal, pixclk
struct video_timing video_640x480_60Hz ={ 8, 96, 40, 640, 800, 33, 2, 10, 480, 525, 25000};
struct video_timing video_720x480_60Hz ={16, 62, 60, 720, 858, 9, 6, 30, 480, 525, 27000};
struct video_timing video_1280x720_60Hz ={110,40, 220,1280, 1650, 5, 5, 20, 720, 750, 74250};
struct video_timing video_1280x720_30Hz ={110,40, 220,1280, 1650, 5, 5, 20, 720, 750, 74250};
struct video_timing video_1366x768_60Hz ={26, 110,110,1366, 1592, 13, 6, 13, 768, 800, 81000};
struct video_timing video_1920x720_60Hz ={148,44, 88, 1920, 2200, 28, 5, 12, 720, 765, 88000};
struct video_timing video_1920x1080_30Hz ={88, 44, 148,1920, 2200, 4, 5, 36, 1080, 1125, 74250};
struct video_timing video_1920x1080_60Hz ={88, 44, 148,1920, 2200, 4, 5, 36, 1080, 1125, 148500};
struct video_timing video_1920x1200_60Hz ={48, 32, 80,1920, 2080, 3, 6, 26, 1200, 1235, 154000};
struct video_timing video_3840x2160_30Hz ={176,88, 296,3840, 4400, 8, 10, 72, 2160, 2250, 297000};void LT9211_ChipID(void)
{HDMI_WriteI2C_Byte(0xff,0x81);//register bankprint("\r\nLT9211 Chip ID:%x,",HDMI_ReadI2C_Byte(0x00));print("%x,",HDMI_ReadI2C_Byte(0x01));print("%x",HDMI_ReadI2C_Byte(0x02));
}/** video chk soft rst **/
void lt9211_vid_chk_rst(void)
{HDMI_WriteI2C_Byte(0xff,0x81); HDMI_WriteI2C_Byte(0x10,0xbe); Timer0_Delay1ms(10);HDMI_WriteI2C_Byte(0x10,0xfe);
}/** lvds rx logic rst **/
void lt9211_lvdsrx_logic_rst(void)
{HDMI_WriteI2C_Byte(0xff,0x81); HDMI_WriteI2C_Byte(0x0c,0xeb);Timer0_Delay1ms(10);HDMI_WriteI2C_Byte(0x0c,0xfb);
}void LT9211_SystemInt(void)
{/* system clock init */ HDMI_WriteI2C_Byte(0xff,0x82);HDMI_WriteI2C_Byte(0x01,0x18);HDMI_WriteI2C_Byte(0xff,0x86);HDMI_WriteI2C_Byte(0x06,0x61); HDMI_WriteI2C_Byte(0x07,0xa8); //fm for sys_clkHDMI_WriteI2C_Byte(0xff,0x87); // ʼ txpll Ĵ б Ĭ ֵ HDMI_WriteI2C_Byte(0x14,0x08); //default valueHDMI_WriteI2C_Byte(0x15,0x00); //default valueHDMI_WriteI2C_Byte(0x18,0x0f);HDMI_WriteI2C_Byte(0x22,0x08); //default valueHDMI_WriteI2C_Byte(0x23,0x00); //default valueHDMI_WriteI2C_Byte(0x26,0x0f);
}void LT9211_LvdsRxPhy(void)
{#ifdef INPUT_PORTAprint("\r\nPort A PHY Config");HDMI_WriteI2C_Byte(0xff,0x82);HDMI_WriteI2C_Byte(0x02,0x8B); //Port A LVDS mode enableHDMI_WriteI2C_Byte(0x05,0x21); //port A CLK lane swapHDMI_WriteI2C_Byte(0x07,0x1f); //port A clk enableHDMI_WriteI2C_Byte(0x04,0xa0); //select port A clk as byteclk//HDMI_WriteI2C_Byte(0x09,0xFC); //port A P/N swapHDMI_WriteI2C_Byte(0xff,0x86); HDMI_WriteI2C_Byte(0x33,0xe4); //Port A Lane swap#endif#ifdef INPUT_PORTBprint("\r\nPort B PHY Config");HDMI_WriteI2C_Byte(0xff,0x82);HDMI_WriteI2C_Byte(0x02,0x88); //Port A/B LVDS mode enableHDMI_WriteI2C_Byte(0x05,0x21); //port A CLK lane swap and rterm turn-offHDMI_WriteI2C_Byte(0x0d,0x21); //port B CLK lane swapHDMI_WriteI2C_Byte(0x07,0x1f); //port A clk enable (ֻ Portbʱ,porta lane0 clkҪ )HDMI_WriteI2C_Byte(0x0f,0x1f); //port B clk enable//HDMI_WriteI2C_Byte(0x10,0x00); //select port B clk as byteclkHDMI_WriteI2C_Byte(0x04,0xa1); //reserve//HDMI_WriteI2C_Byte(0x11,0x01); //port B P/N swapHDMI_WriteI2C_Byte(0x10,0xfc);HDMI_WriteI2C_Byte(0xff,0x86); HDMI_WriteI2C_Byte(0x34,0xe4); //Port B Lane swapHDMI_WriteI2C_Byte(0xff,0xd8); HDMI_WriteI2C_Byte(0x16,0x80);#endifHDMI_WriteI2C_Byte(0xff,0x81);HDMI_WriteI2C_Byte(0x20,0x7f); HDMI_WriteI2C_Byte(0x20,0xff); //mlrx calib reset
}void LT9211_LvdsRxDigital(void)
{ HDMI_WriteI2C_Byte(0xff,0x85);HDMI_WriteI2C_Byte(0x88,0x10); //LVDS input, MIPI outputHDMI_WriteI2C_Byte(0xff,0xd8);if(INPUT_PORT_NUM == 1) //1Port LVDS Input{HDMI_WriteI2C_Byte(0x10,0x80);print("\r\nLVDS Port Num: 1");}else if(INPUT_PORT_NUM == 2) //2Port LVDS Input{HDMI_WriteI2C_Byte(0x10,0x00);print("\r\nLVDS Port Num: 2");}else{print("\r\nPort Num Set Error");} lt9211_vid_chk_rst(); //video chk soft rstlt9211_lvdsrx_logic_rst(); //lvds rx logic rst HDMI_WriteI2C_Byte(0xff,0x86);HDMI_WriteI2C_Byte(0x30,0x45); //port AB input port sel if(LVDS_FORMAT == JEDIA_FORMAT){HDMI_WriteI2C_Byte(0xff,0x85);HDMI_WriteI2C_Byte(0x59,0xd0); HDMI_WriteI2C_Byte(0xff,0xd8);HDMI_WriteI2C_Byte(0x11,0x40);}
}int lt9211_lvds_clkstb_check(void)
{u8 porta_clk_state = 0;u8 portb_clk_state = 0;HDMI_WriteI2C_Byte(0xff,0x86);HDMI_WriteI2C_Byte(0x00,0x01);Timer0_Delay1ms(300);porta_clk_state = (HDMI_ReadI2C_Byte(0x08) & (0x20));HDMI_WriteI2C_Byte(0xff,0x86);HDMI_WriteI2C_Byte(0x00,0x02);Timer0_Delay1ms(300);portb_clk_state = (HDMI_ReadI2C_Byte(0x08) & (0x20));if(INPUT_PORT_NUM == 1){#ifdef INPUT_PORTAif( porta_clk_state ){return 1;}else{return 0;}#endif#ifdef INPUT_PORTBif( portb_clk_state ){return 1;}else{return 0;}#endif}else if(INPUT_PORT_NUM == 2){if(porta_clk_state && portb_clk_state){return 1;}else{return 0;}}
}void LT9211_ClockCheckDebug(void)
{
#ifdef _uart_debug_u32 fm_value;lvds_clk_in = 0;#ifdef INPUT_PORTAHDMI_WriteI2C_Byte(0xff,0x86);HDMI_WriteI2C_Byte(0x00,0x01);Timer0_Delay1ms(50);fm_value = 0;fm_value = (HDMI_ReadI2C_Byte(0x08) &(0x0f));fm_value = (fm_value<<8) ;fm_value = fm_value + HDMI_ReadI2C_Byte(0x09);fm_value = (fm_value<<8) ;fm_value = fm_value + HDMI_ReadI2C_Byte(0x0a);print("\r\nPort A lvds clock: ");printdec_u32(fm_value);lvds_clk_in = fm_value;#endif#ifdef INPUT_PORTBHDMI_WriteI2C_Byte(0xff,0x86);HDMI_WriteI2C_Byte(0x00,0x02);Timer0_Delay1ms(50);fm_value = 0;fm_value = (HDMI_ReadI2C_Byte(0x08) &(0x0f));fm_value = (fm_value<<8) ;fm_value = fm_value + HDMI_ReadI2C_Byte(0x09);fm_value = (fm_value<<8) ;fm_value = fm_value + HDMI_ReadI2C_Byte(0x0a);print("\r\nPort B lvds clock: ");printdec_u32(fm_value);lvds_clk_in = fm_value;#endif#endif
}void LT9211_LvdsRxPll(void)
{u8 loopx = 0;HDMI_WriteI2C_Byte(0xff,0x82);HDMI_WriteI2C_Byte(0x25,0x05);HDMI_WriteI2C_Byte(0x27,0x02); if(INPUT_PORT_NUM == 1) //1Port LVDS Input{HDMI_WriteI2C_Byte(0x24,0x24); //RXPLL_LVDSCLK_MUXSEL,PIXCLK_MUXSEL 0x2c.HDMI_WriteI2C_Byte(0x28,0x44); //0x64}else if(INPUT_PORT_NUM == 2) //2Port LVDS Input{HDMI_WriteI2C_Byte(0x24,0x2c); //RXPLL_LVDSCLK_MUXSEL,PIXCLK_MUXSEL 0x2c.HDMI_WriteI2C_Byte(0x28,0x64); //0x64}else{print("\r\n LvdsRxPll: lvds port count error");}Timer0_Delay1ms(10);HDMI_WriteI2C_Byte(0xff,0x87);HDMI_WriteI2C_Byte(0x05,0x00);HDMI_WriteI2C_Byte(0x05,0x80);Timer0_Delay1ms(100);for(loopx = 0; loopx < 10; loopx++) //Check Rx PLL cal{HDMI_WriteI2C_Byte(0xff,0x87); if(HDMI_ReadI2C_Byte(0x12)& 0x80){if(HDMI_ReadI2C_Byte(0x11)& 0x80){print("\r\nLT9211 rx cal done");}else{print("\r\nLT9211 rx cal undone!!");} print("\r\nLT9211 rx pll lock");break;}else{print("\r\nLT9211 rx pll unlocked");}}
}void LT9211_VideoCheck(void)
{u8 sync_polarity;HDMI_WriteI2C_Byte(0xff,0x86);HDMI_WriteI2C_Byte(0x20,0x00);sync_polarity = HDMI_ReadI2C_Byte(0x70);vs = HDMI_ReadI2C_Byte(0x71);hs = HDMI_ReadI2C_Byte(0x72);hs = (hs<<8) + HDMI_ReadI2C_Byte(0x73);vbp = HDMI_ReadI2C_Byte(0x74);vfp = HDMI_ReadI2C_Byte(0x75);hbp = HDMI_ReadI2C_Byte(0x76);hbp = (hbp<<8) + HDMI_ReadI2C_Byte(0x77);hfp = HDMI_ReadI2C_Byte(0x78);hfp = (hfp<<8) + HDMI_ReadI2C_Byte(0x79);vtotal = HDMI_ReadI2C_Byte(0x7A);vtotal = (vtotal<<8) + HDMI_ReadI2C_Byte(0x7B);htotal = HDMI_ReadI2C_Byte(0x7C);htotal = (htotal<<8) + HDMI_ReadI2C_Byte(0x7D);vact = HDMI_ReadI2C_Byte(0x7E);vact = (vact<<8)+ HDMI_ReadI2C_Byte(0x7F);hact = HDMI_ReadI2C_Byte(0x80);hact = (hact<<8) + HDMI_ReadI2C_Byte(0x81);print("\r\nsync_polarity = %x", sync_polarity);if(!(sync_polarity & 0x01)) //hsync{HDMI_WriteI2C_Byte(0xff,0xd8);HDMI_WriteI2C_Byte(0x10, (HDMI_ReadI2C_Byte(0x10)| 0x10));}if(!(sync_polarity & 0x02)) //vsync{HDMI_WriteI2C_Byte(0xff,0xd8);HDMI_WriteI2C_Byte(0x10, (HDMI_ReadI2C_Byte(0x10)| 0x20));}print("\r\nhfp, hs, hbp, hact, htotal = ");printdec_u32(hfp);printdec_u32(hs);printdec_u32(hbp);printdec_u32(hact);printdec_u32(htotal);print("\r\nvfp, vs, vbp, vact, vtotal = ");printdec_u32(vfp);printdec_u32(vs);printdec_u32(vbp);printdec_u32(vact);printdec_u32(vtotal);if ((hact == video_1280x720_60Hz.hact ) &&( vact == video_1280x720_60Hz.vact )){print("\r\nvideo_1280x720_60Hz"); pVideo_Format = &video_1280x720_60Hz;}else if ((hact == video_1920x1080_60Hz.hact ) &&( vact == video_1920x1080_60Hz.vact )){print("\r\nvideo_1920x1080_60Hz"); pVideo_Format = &video_1920x1080_60Hz;}else {pVideo_Format = NULL;print("\r\nvideo_none"); }
}void LT9211_MipiTxpll(void)
{u8 loopx;HDMI_WriteI2C_Byte(0xff,0x82);HDMI_WriteI2C_Byte(0x36,0x03); //b7:txpll_pdHDMI_WriteI2C_Byte(0x37,0x28);HDMI_WriteI2C_Byte(0x38,0x44);HDMI_WriteI2C_Byte(0x3a,0x93);HDMI_WriteI2C_Byte(0xff,0x87);HDMI_WriteI2C_Byte(0x13,0x00);HDMI_WriteI2C_Byte(0x13,0x80);Timer0_Delay1ms(100);for(loopx = 0; loopx < 10; loopx++) //Check Tx PLL cal done{HDMI_WriteI2C_Byte(0xff,0x87); if(HDMI_ReadI2C_Byte(0x1f)& 0x80){if(HDMI_ReadI2C_Byte(0x20)& 0x80){print("\r\nLT9211 tx pll lock");}else{print("\r\nLT9211 tx pll unlocked");} print("\r\nLT9211 tx pll cal done");break;}else{print("\r\nLT9211 tx pll unlocked");}}
}void LT9211_MipiTxPhy(void)
{ HDMI_WriteI2C_Byte(0xff,0x82);HDMI_WriteI2C_Byte(0x62,0x00); //ttl output disableHDMI_WriteI2C_Byte(0x3b,0x32); //mipi en HDMI_WriteI2C_Byte(0xff,0x81);HDMI_WriteI2C_Byte(0x20,0xfb);Timer0_Delay1ms(10);HDMI_WriteI2C_Byte(0x20,0xff); //tx rterm calibration//HDMI_WriteI2C_Byte(0x48,0x5f); //Port A Lane P/N Swap//HDMI_WriteI2C_Byte(0x49,0x92); //HDMI_WriteI2C_Byte(0x52,0x5f); //Port B Lane P/N Swap//HDMI_WriteI2C_Byte(0x53,0x92); HDMI_WriteI2C_Byte(0xff,0x86); HDMI_WriteI2C_Byte(0x40,0x80); //tx_src_sel/*port src sel*/HDMI_WriteI2C_Byte(0x41,0x01); HDMI_WriteI2C_Byte(0x42,0x23);HDMI_WriteI2C_Byte(0x43,0x40); //Port A MIPI Lane SwapHDMI_WriteI2C_Byte(0x44,0x12);HDMI_WriteI2C_Byte(0x45,0x34); //Port B MIPI Lane Swap
}void LT9211_MipiTxDigital(void)
{ HDMI_WriteI2C_Byte(0xff,0xd4);HDMI_WriteI2C_Byte(0x1c,0x30); //hs_rqst_preHDMI_WriteI2C_Byte(0x1d,0x0a); //lpxHDMI_WriteI2C_Byte(0x1e,0x06); //prprHDMI_WriteI2C_Byte(0x1f,0x0a); //trailHDMI_WriteI2C_Byte(0x21,0x00); //[5]byte_swap,[0]burst_clkHDMI_WriteI2C_Byte(0xff,0xd4); HDMI_WriteI2C_Byte(0x12,0x1E);HDMI_WriteI2C_Byte(0x15,0x01);HDMI_WriteI2C_Byte(0x16,0x55); HDMI_WriteI2C_Byte(0x10,0x01);HDMI_WriteI2C_Byte(0x11,0x50); //read byteclkHDMI_WriteI2C_Byte(0x13,0x0f); //bit[5:4]:lane num, bit[2]:bllp,bit[1:0]:vid_modeHDMI_WriteI2C_Byte(0x14,0x04); //bit[5:4]:data typ,bit[2:0]:fmt sel 000:rgb888HDMI_WriteI2C_Byte(0x21,0x02);HDMI_WriteI2C_Byte(0xff,0xd0);HDMI_WriteI2C_Byte(0x04,0x10);
}void LT9211_SetTxTiming(void)
{u16 hact, vact;u16 hs, vs;u16 hbp, vbp;u16 htotal, vtotal;u16 hfp, vfp; hact = pVideo_Format->hact;vact = pVideo_Format->vact;htotal = pVideo_Format->htotal;vtotal = pVideo_Format->vtotal;hs = pVideo_Format->hs;vs = pVideo_Format->vs;hfp = pVideo_Format->hfp;vfp = pVideo_Format->vfp; hbp = pVideo_Format->hbp;vbp = pVideo_Format->vbp;HDMI_WriteI2C_Byte(0xff,0xd4);HDMI_WriteI2C_Byte(0x04,0x01); //hs[7:0] not careHDMI_WriteI2C_Byte(0x05,0x01); //hbp[7:0] not careHDMI_WriteI2C_Byte(0x06,0x01); //hfp[7:0] not careHDMI_WriteI2C_Byte(0x07,(u8)(hact>>8)); //hactive[15:8]HDMI_WriteI2C_Byte(0x08,(u8)(hact)); //hactive[7:0]HDMI_WriteI2C_Byte(0x09,(u8)(vs)+(u8)(vbp) - 1); //vfp[7:0]HDMI_WriteI2C_Byte(0x0a,0x00); //bit[3:0]:vbp[11:8]HDMI_WriteI2C_Byte(0x0b,0x01); //vbp[7:0]HDMI_WriteI2C_Byte(0x0c,(u8)(vact>>8)); //vcat[15:8]HDMI_WriteI2C_Byte(0x0d,(u8)(vact)); //vcat[7:0]HDMI_WriteI2C_Byte(0x0e,0x00); //vfp[11:8]HDMI_WriteI2C_Byte(0x0f,0x00); //vfp[7:0]
}void LT9211_LVDS2MIPIDSI_Config(void)
{print("\r\n*************LT9211 LVDS2MIPIDSI Config*************");LT9211_ChipID();LT9211_SystemInt();LT9211_LvdsRxPhy();LT9211_LvdsRxDigital();LT9211_LvdsRxPll();LT9211_ClockCheckDebug();LT9211_VideoCheck();if( pVideo_Format != NULL ){/********MIPI OUTPUT CONFIG********/LT9211_MipiTxPhy();LT9211_MipiTxpll();LT9211_SetTxTiming();LT9211_MipiTxDigital();}
}/******************************************************************************* @project: LT9211* @file: lt9211.h* @author: zll* @company: LONTIUM COPYRIGHT and CONFIDENTIAL* @date: 2019.04.10
/******************************************************************************/#ifndef _LT9211_H
#define _LT9211_H/******************* LVDS Input Config ********************/
#define INPUT_PORTA
#define INPUT_PORTB#define INPUT_PORT_NUM 2typedef enum LVDS_FORMAT_ENUM{VESA_FORMAT = 0,JEDIA_FORMAT
};
#define LVDS_FORMAT VESA_FORMATtypedef enum LVDS_MODE_ENUM{DE_MODE = 0,SYNC_MODE
};
#define LVDS_MODE SYNC_MODEtypedef struct video_timing{
u16 hfp;
u16 hs;
u16 hbp;
u16 hact;
u16 htotal;
u16 vfp;
u16 vs;
u16 vbp;
u16 vact;
u16 vtotal;
u32 pclk_khz;
};void LT9211_LVDS2MIPIDSI_Config(void);#endif
