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。