v853如何实现对cmos sensor实时的寄存器读写？

[monuannuan]

sensor型号为cis5001。目前自己写的驱动已经可以实现图像显示，但是曝光太暗，也有色偏。想要能够实时调节曝光和白平衡的寄存器。但是在用户代码中写的i2c接口无法顺利访问寄存器。请问各位大佬有没有相关的经验？拜谢！

[iamseer]

@monuannuan
你驱动里有没有 v4l2_ctrl_ops ？
类似

static const struct v4l2_ctrl_ops sensor_ctrl_ops = {
	.g_volatile_ctrl = sensor_g_ctrl,
	.s_ctrl = sensor_s_ctrl,
};

这个sensor_s_ctrl类似：

static int sensor_s_ctrl(struct v4l2_ctrl *ctrl)
{
	struct sensor_info *info =
		container_of(ctrl->handler, struct sensor_info, handler);
	struct v4l2_subdev *sd = &info->sd;

	switch (ctrl->id) {
	case V4L2_CID_GAIN:
		return sensor_s_gain(sd, ctrl->val);
	case V4L2_CID_EXPOSURE:
		return sensor_s_exp(sd, ctrl->val);
	case V4L2_CID_ILLUMINATORS_1:
		return sensor_s_illum1(sd, ctrl->val);
	case V4L2_CID_ILLUMINATORS_2:
		return sensor_s_illum2(sd, ctrl->val);
	}
	return -EINVAL;
}

你在这边的函数里面操作i2c就可以。
然后主程序类似

bool setCameraExposure(int exposure){
    struct v4l2_control ctrl;
    memset(&ctrl, 0, sizeof(struct v4l2_control));
    ctrl.id = V4L2_CID_EXPOSURE;
    ctrl.value = exposure;
    printf("set camera exposure to %d\n", exposure);
    if (ioctl(videofd, VIDIOC_S_CTRL, &ctrl) < 0) {
        printf("set camera exposure failed\n");
        return false;
    }

    return true;
}

这样主程序就能调用驱动操作传感器。