高通平台手机开发之Camera

4.3. Camera

参考文档：

1) 80-NA157-22_PRESENTATION- MSM8974-APQ8074-MSM8X26-APQ8084 LINUX CAMERA OVERVIEW.pdf

2) 80-NE717-1_MSM8974-APQ8074-MSM8X26 LINUX CAMERA SOFTWARE DESIGN DOCUMENT.pdf

3) 80-NU323-2_Multimedia Driver Development and Bringup Guide - Camera.pdf

4) 80-NL239-33_LINUX CAMERA DEBUGGING GUIDE.pdf

4.3.1. Camera软件架构



4.3.2. Kernel驱动

1) 增加dts配置

qcom,camera@5a {//back camera

compatible = “samsung,s5k3m2”;

reg = <0x5a>;

qcom,slave-id = <0x5a 0x0000 0x30d2>;

qcom,csiphy-sd-index = <0>;

qcom,csid-sd-index = <0>;

qcom,mount-angle = <90>;

qcom,sensor-name = “s5k3m2_f13s01k”;

qcom,actuator-src = <&actuator0>;

qcom,led-flash-src = <&led_flash0>;

cam_vdig-supply = <&pm8941_l3>;

cam_vana-supply = <&pm8941_l17>;

cam_vio-supply = <&pm8941_lvs2>;

cam_vaf-supply = <&pm8941_l23>;

qcom,cam-vreg-name = “cam_vdig”, “cam_vio”, “cam_vana”,

“cam_vaf”;

qcom,cam-vreg-type = <0 1 0 0>;

qcom,cam-vreg-min-voltage = <1225000 0 2850000 3000000>;

qcom,cam-vreg-max-voltage = <1225000 0 2850000 3000000>;

qcom,cam-vreg-op-mode = <105000 0 80000 100000>;

qcom,gpio-no-mux = <0>;

gpios = <&msmgpio 15 0>,

<&msmgpio 90 0>;

qcom,gpio-reset = <1>;

qcom,gpio-req-tbl-num = <0 1>;

qcom,gpio-req-tbl-flags = <1 0>;

qcom,gpio-req-tbl-label = “CAMIF_MCLK”,

“CAM_RESET1”;

qcom,gpio-set-tbl-num = <1 1>;

qcom,gpio-set-tbl-flags = <0 2>;

qcom,gpio-set-tbl-delay = <1 1000>;

qcom,csi-lane-assign = <0x4320>;

qcom,csi-lane-mask = <0x1F>;

qcom,sensor-position = <0>;

qcom,sensor-mode = <0>;

qcom,cci-master = <0>;

};

2) 增加驱动文件

kernel/drivers/media/platform/msm/camera_v2/sensor

复制一个原有camera的驱动文件并改名，比如ov8865.c改为s5k3l2.c。打开s5k3l2.c，把里面的ov8865改成s5k3l2, OV8865改为S5K3L2。

在Makefile里加上obj-$(CONFIG_S5K3L2) += s5k3l2.o

s5k3l2.c里需要改动的是上电序列，需要根据原理图来配置

static struct msm_sensor_power_setting s5k3l2_power_setting[] = {

{

.seq_type = SENSOR_VREG,

.seq_val = CAM_VIO,

.config_val = 0,

.delay = 1,

},

{

.seq_type = SENSOR_VREG,

.seq_val = CAM_VANA,

.config_val = 0,

.delay = 1,

},

{

.seq_type = SENSOR_VREG,

.seq_val = CAM_VDIG,

.config_val = 0,

.delay = 1,

},

{

.seq_type = SENSOR_VREG,

.seq_val = CAM_VAF,

.config_val = 0,

.delay = 5,

},

{

.seq_type = SENSOR_GPIO,

.seq_val = SENSOR_GPIO_STANDBY,

.config_val = GPIO_OUT_LOW,

.delay = 1,

},

{

.seq_type = SENSOR_GPIO,

.seq_val = SENSOR_GPIO_RESET,

.config_val = GPIO_OUT_LOW,

.delay = 5,

},

{

.seq_type = SENSOR_GPIO,

.seq_val = SENSOR_GPIO_AF_PWDM,

.config_val = GPIO_OUT_LOW,

.delay = 5,

},

{

.seq_type = SENSOR_GPIO,

.seq_val = SENSOR_GPIO_STANDBY,

.config_val = GPIO_OUT_HIGH,

.delay = 5,

},

{

.seq_type = SENSOR_GPIO,

.seq_val = SENSOR_GPIO_RESET,

.config_val = GPIO_OUT_HIGH,

.delay = 10,

},

{

.seq_type = SENSOR_GPIO,

.seq_val = SENSOR_GPIO_AF_PWDM,

.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,

},

};

3) 调试

在文件：kernel/drivers/media/platform/msm/camera_v2/sensor/msm_sensor.c

打开这个宏：#define CONFIG_MSMB_CAMERA_DEBUG

检查开机时kernel log

CDBG(“%s: read id: %x expected id %x:\n”, func, chipid,

slave_info->sensor_id);

看与camera的i2c通信是否成功。

4.3.3. user space驱动

1) 增加代码

vendor/qcom/proprietary/mm-camera/mm-camera2/media-controller/modules/sensors/sensor_libs/ 里增加一个驱动文件夹s5k3l2，里面有两个文件：Android.mk和s5k3l2_lib.c

一般来说高通会提供驱动，模组厂也会提供相应的驱动。

把驱动加入进去，编译成so，然后push到手机里。或者整个编译成system.img，刷入手机。

有的时候，我们发现系统里找不到camera应用的图标。这是由于系统第一次启动时，后摄的kernel驱动没有准备好。

如何解决：

➢ Kernel驱动调试好后，重新刷userdata.img。让系统重新初始化。

➢ adb shell am start -n com.android.camera/com.android.camera.Camera package和activity的名字需要和手机里的应用匹配，不一定是上面这个名字。

➢ 安装其它的camera应用。

2) 调试

打开camera应用，看看图像预览是否成功。如果不成功，需要调试。

➢ 在代码里打开调试开关

vendor/qcom/proprietary/mm-camera/mm-camera2/media-controller/modules/sensors/sensors/sensor.c

#define SLOW SERR

SLOW(“lib_name %s”, lib_name); 可以看到是否正确库被调用。

➢ Lane配置

qcom,csi-lane-assign = <0x4320>; 这是8974平台的值，其它平台不一样

qcom,csi-lane-mask = <0x1F>; 0x1F for 4lane, 0x7 for 2 lane, 0x3 for 1 lane

这个配置每个平台不一样。

大部分情况下，到这里基本就调通了，可以预览了。如果一直调不调，有可能是模块硬件有问题，需要和模组厂一起跳。

3) 从头创建lib.c文件

在某些情况下，如果不能得到驱动文件，需要根据芯片厂商的数据手册和高通的文档来自己写lib.c

4.3.4. 闪光灯

这是系统图自带闪光灯的配置

qcom,leds@d300 {

status = “okay”;

pm8941_flash0: qcom,flash_0 {

qcom,max-current = <1000>;

qcom,default-state = “off”;

qcom,headroom = <3>;

qcom,duration = <1280>;

qcom,clamp-curr = <200>;

qcom,startup-dly = <3>;

qcom,safety-timer;

label = “flash”;

linux,default-trigger =

“flash0_trigger”;

qcom,id = <1>;

linux,name = “led:flash_0”;

qcom,current = <625>;

};

使用时做camera的配置文件里加上就行。

qcom,led-flash-src = <&led_flash0>;

4.3.5. 对焦马达

Kernel里面的驱动都是一样的，主要的改动在user space

vendor/qcom/proprietary/mm-camera/mm-camera2/media-controller/modules/sensors/actuator_libs

vendor/qcom/proprietary/mm-camera/mm-camera2/media-controller/modules/sensors/actuators

4.3.6. Tuning

马达，闪光灯，拍照效果都是要Tuning的。但是需要实验室环境来做。

注意：在马达的内核驱动里加上过多log，可能导致马达不能正常对焦。