hdmitx_boot_para_setup

"bootargs=init=/init console=ttyS0,115200n8 hlt no_console_suspend vmalloc=256m mem=1024m logo=osd1,loaded,panel,debug hdmitx=    vdacoff,powermode1,unplug_powerdown\0" \

这是uboot里面CONFIG_EXTRA_ENV_SETTINGS的设置；

其中的vdacoff,powermode1,unplug_powerdown

查看/kernel/driver/xxx/hdmi/htmi-tx.c

其中一段代码如下：

static  int __init hdmitx_boot_para_setup(char *s){    char separator[]={' ',',',';',0x0};    char *token;    unsigned token_len, token_offset, offset=0;    unsigned long cec_flag;    int size=strlen(s);        HDMI_DEBUG();    do{        token=next_token_ex(separator, s, size, offset, &token_len, &token_offset);        if(token){            if((token_len==3) && (strncmp(token, "off", token_len)==0)){                init_flag|=INIT_FLAG_NOT_LOAD;            }            else if((token_len==7) && (strncmp(token, "vdacoff", token_len)==0)){                init_flag|=INIT_FLAG_VDACOFF;            }            else if((token_len==16) && (strncmp(token, "unplug_powerdown", token_len)==0)){                init_flag|=INIT_FLAG_POWERDOWN;            }            else if(strncmp(token, "pllmode1",  8)==0){                    /* use external xtal as source of hdmi pll */                hdmi_pll_mode = 1;            }            else if((token_len==7)&& (strncmp(token, "hpdmode", token_len)==0)){                hpdmode = simple_strtoul(token+7,NULL,10);               }            else if((token_len==3)&&(strncmp(token, "rgb", 3)==0)){                hdmitx_output_rgb();                }            else if(strncmp(token, "audpara", 7)==0){                int tmp;                tmp = simple_strtoul(token+7,NULL,10);                hdmi_set_audio_para(tmp);                printk("hdmi: set hdmi aud_para %d\n", tmp);            }            else if(strncmp(token, "bufsize", 7)==0){                int tmp;                tmp = simple_strtoul(token+7,NULL,10);                if(tmp>=1024){                    hdmi_log_buf_size=0;                    hdmi_log_rd_pos=0;                       hdmi_log_wr_pos=0;                       hdmi_log_buf_size=tmp;                    printk("hdmi: set log buffer size %d\n", tmp);                }                        }            else if(strncmp(token, "powermode", 9)==0){                int tmp;                tmp = simple_strtoul(token+9,NULL,10);                init_powermode=tmp|0x80;                printk("hdmi: set init powermode %d\n", tmp);                            }            else if(strncmp(token, "audiooff", 8)==0){                hdmi_audio_off_flag = 1;                printk("hdmi: set no audio output\n");            }            else if(strncmp(token, "prbs", 4)==0){                hdmi_prbs_mode = simple_strtoul(token+4,NULL,16);                printk("hdmi, set prbs mode as %x always\n", hdmi_prbs_mode);                }            else if(strncmp(token, "480p_clk", 8)==0){                hdmi_480p_force_clk = simple_strtoul(token+8,NULL,10);                printk("hdmi, set 480p mode clock as %dMHz always\n", hdmi_480p_force_clk);                }            else if(strncmp(token, "cec", 3)==0){                hdmi_cec_func_config |= INIT_FLAG_CEC_FUNC>>2;                aml_write_reg32(P_AO_DEBUG_REG0, aml_read_reg32(P_AO_DEBUG_REG0) | (hdmi_cec_func_config & 0xf));                                printk("hdmi: enable cec function\n");                                cec_flag = simple_strtoul(token+3,NULL,16);                                   if(((cec_flag >> 1) & 0x1) == 1){                    hdmi_cec_func_config |= CEC_ONE_TOUCH_PLAY>>2;                    aml_write_reg32(P_AO_DEBUG_REG0, aml_read_reg32(P_AO_DEBUG_REG0) | (hdmi_cec_func_config & 0xf));                    printk("hdmi: enable cec one touch play function\n");                    }else{                    hdmi_cec_func_config &= ~(CEC_ONE_TOUCH_PLAY>>2);                    aml_write_reg32(P_AO_DEBUG_REG0, aml_read_reg32(P_AO_DEBUG_REG0) & (~(hdmi_cec_func_config & 0xf)));                    printk("hdmi: disable cec one touch play function\n");                                     }                            if(((cec_flag >> 2) & 0x1) == 1){                    hdmi_cec_func_config |= CEC_ONE_TOUCH_STANDBY>>2;                    aml_write_reg32(P_AO_DEBUG_REG0, aml_read_reg32(P_AO_DEBUG_REG0) | (hdmi_cec_func_config & 0xf));                    printk("hdmi: enable cec one touch standby function\n");                    }else{                    hdmi_cec_func_config &= ~(CEC_ONE_TOUCH_STANDBY>>2);                    aml_write_reg32(P_AO_DEBUG_REG0, aml_read_reg32(P_AO_DEBUG_REG0) & (~(hdmi_cec_func_config & 0xf)));                    printk("hdmi: disable cec one touch standby function\n");                                         }                if(((cec_flag >> 3) & 0x1) == 1){                    hdmi_cec_func_config |= CEC_AUTO_POWERON_FROM_TV>>2;                    aml_write_reg32(P_AO_DEBUG_REG0, aml_read_reg32(P_AO_DEBUG_REG0) | (hdmi_cec_func_config & 0xf));                    printk("hdmi: enable cec auto power on form TV function\n");                    }else{                hdmi_cec_func_config &= ~(CEC_AUTO_POWERON_FROM_TV>>2);                aml_write_reg32(P_AO_DEBUG_REG0, aml_read_reg32(P_AO_DEBUG_REG0) & (~(hdmi_cec_func_config & 0xf)));                    printk("hdmi: disable cec auto power on form TV function\n");                                     }            }else{                hdmi_cec_func_config &= ~(INIT_FLAG_CEC_FUNC>>2);                aml_write_reg32(P_AO_DEBUG_REG0, aml_read_reg32(P_AO_DEBUG_REG0) & (~(hdmi_cec_func_config & 0xf)));                printk("hdmi: disable cec function\n");               }               printk("HDMI aml_read_reg32(P_AO_DEBUG_REG0):0x%x\n",aml_read_reg32(P_AO_DEBUG_REG0));               printk("HDMI hdmi_cec_func_config:0x%x\n",hdmi_cec_func_config);                                    }            offset=token_offset;    }while(token);    return 0;}

我了uboot里面的内核参数配置。然后看了系统的串口日志：

[    0.000000@0] HDMI DEBUG: hdmitx_boot_para_setup [1797][    0.000000@0] HDMI aml_read_reg32(P_AO_DEBUG_REG0):0x0[    0.000000@0] HDMI hdmi_cec_func_config:0x0[    0.000000@0] hdmi: set init powermode 1[    0.000000@0] HDMI aml_read_reg32(P_AO_DEBUG_REG0):0x0[    0.000000@0] HDMI hdmi_cec_func_config:0x0[    0.000000@0] HDMI aml_read_reg32(P_AO_DEBUG_REG0):0x0[    0.000000@0] HDMI hdmi_cec_func_config:0x0

next_token_ex将UBOOT传入的环境变量进行解析，然后一个个比较来设置相关的寄存器。