高通平台mm-camera上电时序

背景

作为高通平台Camera知识的一种补充。

参考文档：https://blog.csdn.net/m0_37166404/article/details/64920910

介绍

高通平台对于camera的代码组织，大体上还是遵循Android的框架，即：

上层应用和HAL层交互，高通平台在HAL层里面实现自己的一套管理策略；
在kernel中实现sensor的底层驱动；
对于最核心的sensor端的底层设置、ISP效果相关等代码则是单独进行了抽离，放在vendor中。

上电时序

时序属性

路径：vendor/qcom/proprietary/mm-camera/mm-camera2/media-controller/modules/sensors/includes/sensor_lib.h

最终位于：kernel/include/media/msm_camsensor_sdk.h

struct msm_sensor_power_setting {
    enum msm_sensor_power_seq_type_t seq_type;
    uint16_t seq_val;
    long config_val;
    uint16_t delay;
    void *data[10];
};

有关的时序设置

以：ov5648_q5v22e 为例。

对照规格书：

把DOVDD上电后，AVDD,DVDD,PWDNB的上电时序都大于图中规定时间。

路径：vendor/qcom/proprietary/mm-camera/mm-camera2/media-controller/modules/sensors/sensor_libs/xxx

例如：vendor/qcom/proprietary/mm-camera/mm-camera2/media-controller/modules/sensors/sensor_libs/ov5648_q5v22e当中的ov5648_q5v22e_lib.c

下面这个结构体便是上电时序

tatic struct msm_sensor_power_setting ov5648_q5v22e_power_setting[] = {
  {
    .seq_type = SENSOR_VREG,
    .seq_val = CAM_VIO,
    .config_val = 0,
    .delay = 0,
  },
  {
    .seq_type = SENSOR_VREG,
    .seq_val = CAM_VANA,
    .config_val = 0,
    .delay = 0,
  },
  {
    .seq_type = SENSOR_VREG,
    .seq_val = CAM_VAF,
    .config_val = 0,
    .delay = 0,
  },
  {
    .seq_type = SENSOR_GPIO,
    .seq_val = SENSOR_GPIO_AF_PWDM,
    .config_val = GPIO_OUT_LOW,
    .delay = 1,
  },
  {
    .seq_type = SENSOR_GPIO,
    .seq_val = SENSOR_GPIO_AF_PWDM,
    .config_val = GPIO_OUT_HIGH,
    .delay = 5,
  },
  {
    .seq_type = SENSOR_GPIO,
    .seq_val = SENSOR_GPIO_RESET,
    .config_val = GPIO_OUT_LOW,
    .delay = 0,
  },
  {
    .seq_type = SENSOR_GPIO,
    .seq_val = SENSOR_GPIO_RESET,
    .config_val = GPIO_OUT_HIGH,
    .delay = 10,
  },
  {
    .seq_type = SENSOR_GPIO,
    .seq_val = SENSOR_GPIO_STANDBY,
    .config_val = GPIO_OUT_LOW,
    .delay = 0,
  },
  {
    .seq_type = SENSOR_GPIO,
    .seq_val = SENSOR_GPIO_STANDBY,
    .config_val = GPIO_OUT_HIGH,
    .delay = 5,
  },
  {
    .seq_type = SENSOR_CLK,
    .seq_val = SENSOR_CAM_MCLK,
    .config_val = 24000000,
    .delay = 10,
  },
  {
    .seq_type = SENSOR_I2C_MUX,
    .seq_val = 0,
    .config_val = 0,
    .delay = 0,
  },
};

它会被下列的结构体中使用：

static struct msm_camera_sensor_slave_info sensor_slave_info = {
    //...
    /* power up / down setting */
    .power_setting_array = {
        .power_setting = ov5648_q5v22e_power_setting,
        .size = ARRAY_SIZE(ov5648_q5v22e_power_setting),
        .power_down_setting = power_down_setting,
        .size_down = ARRAY_SIZE(power_down_setting),
    },
};

这些Camera的属性具体在msm_camsensor_sdk定义。

最终位于：kernel/include/media/msm_camsensor_sdk.h

struct msm_camera_sensor_slave_info {
...
	struct msm_sensor_power_setting_array power_setting_array;
...
};

struct msm_sensor_power_setting {
	enum msm_sensor_power_seq_type_t seq_type;
	uint16_t seq_val;
	long config_val;
	uint16_t delay;
	void *data[10];
};

struct msm_sensor_power_setting_array {
	struct msm_sensor_power_setting  power_setting_a[MAX_POWER_CONFIG];
	struct msm_sensor_power_setting *power_setting;
	uint16_t size;
	struct msm_sensor_power_setting  power_down_setting_a[MAX_POWER_CONFIG];
	struct msm_sensor_power_setting *power_down_setting;
	uint16_t size_down;
};

驱动流程解析

在此之前是ioctl，注册到v4l2子系统中。从vendor中把时序结构体的内容传递到kernel中的过程如下：

注意：vendor中的addr_type、camera_id、slave_addr等信息也是按照这样的方法从vendor中传递到kernel中的，可以加打印调试信息看这些值正确与否。

++ kernel/drivers/media/platform/msm/camera_v2/sensor/msm_sensor_init.c
msm_sensor_init_subdev_ioctl()
    msm_sensor_driver_cmd() : case VIDIOC_MSM_SENSOR_INIT_CFG
++ kernel/drivers/media/platform/msm/camera_v2/sensor/msm_sensor_driver.c
	    msm_sensor_driver_probe()
    		copy_from_user((void *)&setting32, setting,sizeof(setting32))
    		// 把 vendor 的时序传递完毕
    		slave_info->power_setting_array.size = setting32.power_setting_array.size;
			slave_info->power_setting_array.power_setting = 
                compat_ptr(setting32.power_setting_array.power_setting); 
			// 把slave_info的上电时序传递给s_ctrl结构体
			msm_sensor_get_power_settings
                msm_sensor_get_power_up_settings(setting, slave_info, power_info);
    		
		    /* 校正时序中SENSOR_VREG的seq_val，为设备树的CAM_VIO */
		    msm_camera_fill_vreg_params();
			/* 执行真正的上电程序*/
			s_ctrl->func_tbl->sensor_power_up(s_ctrl);
				(msm_sensor_power_up)
					由于之前有  .sensor_power_up = msm_sensor_power_up,
					所以最终为： msm_sensor_power_up
++ kernel/drivers/media/platform/msm/camera_v2/sensor/msm_sensor.c
					 //把s_ctrl的上电信息传递给power_info
				    power_info = &s_ctrl->sensordata->power_info;
				    sensor_i2c_client = s_ctrl->sensor_i2c_client;
				    slave_info = s_ctrl->sensordata->slave_info;
				    sensor_name = s_ctrl->sensordata->sensor_name;

				    // 通过之前设置好的时序上电
				    rc = msm_camera_power_up(power_info, 
                                             s_ctrl->sensor_device_type,
                                             sensor_i2c_client);

msm_camera_power_up流程分析

解析这个上电函数：

int msm_camera_power_up(struct msm_camera_power_ctrl_t *ctrl,
                        enum msm_camera_device_type_t device_type,
                        struct msm_camera_i2c_client *sensor_i2c_client)
{
    struct msm_sensor_power_setting *power_setting = NULL;
    //...
    rc = msm_camera_request_gpio_table( //申请gpio
        ctrl->gpio_conf->cam_gpio_req_tbl,
        ctrl->gpio_conf->cam_gpio_req_tbl_size, 1);
    //...
    index = 0; index < ctrl->power_setting_size; index++) {
        //把时序的节点一个一个取下来解析
        power_setting = &ctrl->power_setting[index];     
         //判断类型
        switch (power_setting->seq_type) {                 
            case SENSOR_CLK:
                if (power_setting->config_val)
                    ctrl->clk_info[power_setting->seq_val].clk_rate = power_setting->config_val;
                //camera频率使能
                rc = msm_cam_clk_enable(...1);                  
                //...
            case SENSOR_GPIO:
                //...
                //拉高拉低gpio口
                gpio_set_value_cansleep(ctrl->gpio_conf->gpio_num_info->gpio_num[power_setting->seq_val],
                                        (int) power_setting->config_val);          
                //...
            case SENSOR_VREG:
                //函数里面打开reg_ptr的电源控制器regulator_enable，稍后会解析
                if (power_setting->seq_val < ctrl->num_vreg)
                    msm_camera_config_single_vreg(...,1);  
                //...
            case SENSOR_I2C_MUX:
                if (ctrl->i2c_conf && ctrl->i2c_conf->use_i2c_mux)
                    msm_camera_enable_i2c_mux(ctrl->i2c_conf);   //打开使能i2c_mux
                break;
            default:
                //...
        }
        //以下是每个时序节点解析完毕后，进行的延迟，可以没有
        if (power_setting->delay > 20) {
            msleep(power_setting->delay);
        } else if (power_setting->delay) {
            usleep_range(power_setting->delay * 1000,(power_setting->delay * 1000) + 1000);
        }
    }
    //...
    return 0;
}

两个特殊节点

SENSOR_VREG

在解析设备树节点的时候：

		//从中有一路电vio为0V
		qcom,cam-vreg-name = "cam_vdig", "cam_vio", "cam_vana";//"cam_vaf";
		qcom,cam-vreg-min-voltage = <1800000 0 2850000 >;//2800000>;
		qcom,cam-vreg-max-voltage = <1800000 0 2850000 >;//2800000>;
		qcom,cam-vreg-op-mode = <200000 0 80000 100000>;
		//在kernel中对设备树节点解析的时候
		for (i = 0; i < count; i++) {
			vreg[i].min_voltage = vreg_array[i];}//存入结构体中

在msm_sensor_driver_probe函数中调用msm_camera_fill_vreg_params，在里面遍历上电时序节点：

for (i = 0; i < power_setting_size; i++)
{
    if (power_setting[i].seq_type != SENSOR_VREG)
        continue;

    switch (power_setting[i].seq_val) {
        case CAM_VDIG:
            //...
        case CAM_VIO:
            for (j = 0; j < num_vreg; j++) {
                if (!strcmp(cam_vreg[j].reg_name, "cam_vio")) {
                    power_setting[i].seq_val = j;   // 让seq_val 对准设备树的seq_val 
                    break;
                }
            }
            break;
        //...
    }
}

// 再进入此节点上电的时候有下列的语句，中间的参数就是设备树上的电压。
msm_camera_config_single_vreg(..&ctrl->cam_vreg[power_setting->seq_val],..);

SENSOR_I2C_MUX

执行函数msm_camera_enable_i2c_mux—>可能是申请锁和一帧的内存空间

解析完毕后，最后两个节点是打开时序和I2C_MUX，如果成功上电便完成了。

posted @ 2021-01-25 11:38 schips 阅读(1940) 评论(0) 编辑收藏举报

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黄树超

非典型嵌入式行业从业者；C/C++，Linux/Android

高通平台mm-camera上电时序

高通平台mm-camera上电时序

背景

介绍

上电时序

时序属性

有关的时序设置

驱动流程解析

msm_camera_power_up流程分析

两个特殊节点

SENSOR_VREG

SENSOR_I2C_MUX