MTK6580（Android6.0)-camera 驱动分析
一、MTK6580 平台 Camera 驱动整体框架
mtk平台三大件调试中，camera的调试难度最大，问题也就最多，为此特地分析了一下整个camera驱动部分
实现过程，以下为camera驱动框架序列图：
从图中可以看出，整个框架分为三个部分hal部分逻辑调用，kernel层的通用驱动sensorlist.c 和具体IC的驱动
xxxx_mipi_raw.c，kernel起来后不会直接去访问硬件sensor,而是会注册相关的驱动，之后Android系统起来后
会启动相关的服务如：camera_service，在camera服务中会直接去访问hal,kernel驱动，进而操作camera。
为此本文也穿插了部分hal层的调用,至于camera_service后面章节会继续补充。
二、 Camera 驱动的具体实现
========================HAL 层部分初始调用========================文件：vendor/mediatek/proprietary/hardware/mtkcam/common/module_hal/devicemgr/CamDeviceManagerBase.cpp
int32_t
CamDeviceManagerBase::
getNumberOfDevices()
{
...
mi4DeviceNum = enumDeviceLocked();
...
}int32_t
CamDeviceManagerImp::
enumDeviceLocked()
{
...
//------------------------------------------------------------------------------
#if '1'==MTKCAM_HAVE_SENSOR_HAL
//
IHalSensorList*const pHalSensorList = IHalSensorList::get();
size_t const sensorNum = pHalSensorList->searchSensors();
#endif
...
return i4DeviceNum;
}MUINT
HalSensorList::
searchSensors()
{
Mutex::Autolock _l(mEnumSensorMutex);
//
MY_LOGD("searchSensors");
return enumerateSensor_Locked();
}MUINT
HalSensorList::
enumerateSensor_Locked()
{
....
MUINT halSensorDev = SENSOR_DEV_NONE;
NSFeature::SensorInfoBase* pSensorInfo ;
SensorDrv *const pSensorDrv = SensorDrv::get();
SeninfDrv *const pSeninfDrv = SeninfDrv::createInstance();
int const iSensorsList = pSensorDrv->impSearchSensor(NULL);
....
}MINT32
ImgSensorDrv::impSearchSensor(pfExIdChk pExIdChkCbf)
{
....
GetSensorInitFuncList(&m_pstSensorInitFunc);
LOG_MSG("SENSOR search start \n");
sprintf(cBuf,"/dev/%s",CAMERA_HW_DEVNAME);
m_fdSensor = ::open(cBuf, O_RDWR);
......
for (i = 0; i < MAX_NUM_OF_SUPPORT_SENSOR; i++) {
....
err = ioctl(m_fdSensor, KDIMGSENSORIOC_X_SET_DRIVER,&id[KDIMGSENSOR_INVOKE_DRIVER_0] );
...
err = ioctl(m_fdSensor, KDIMGSENSORIOC_T_CHECK_IS_ALIVE);
......
}文件：vendor/mediatek/proprietary/custom/mt6580/hal/imgsensor_src/sensorlist.cpp
UINT32 GetSensorInitFuncList(MSDK_SENSOR_INIT_FUNCTION_STRUCT **ppSensorList)
{
if (NULL == ppSensorList) {
ALOGE("ERROR: NULL pSensorList\n");
return MHAL_UNKNOWN_ERROR;
}
*ppSensorList = &SensorList[0];
return MHAL_NO_ERROR;
} MSDK_SENSOR_INIT_FUNCTION_STRUCT SensorList[] =
{
//xc add camera start
#if defined(GC2365MIPI_RAW)
RAW_INFO(GC2365MIPI_SENSOR_ID, SENSOR_DRVNAME_GC2365MIPI_RAW, NULL),
#endif
#if defined(GC2355_MIPI_RAW_BAIKANG_M8112)
RAW_INFO(GC2355_SENSOR_ID, SENSOR_DRVNAME_GC2355_MIPI_RAW,NULL),
#endif
....
}err = ioctl(m_fdSensor, KDIMGSENSORIOC_X_SET_DRIVER,&id[KDIMGSENSOR_INVOKE_DRIVER_0] );
err = ioctl(m_fdSensor, KDIMGSENSORIOC_T_CHECK_IS_ALIVE);
访问kernel层的数据
====================== Kernel 层驱动的实现 ========================
1. 针对前后摄注册platform 设备和驱动
文件：kernel-3.18/drivers/misc/mediatek/imgsensor/src/mt6580/kd_sensorlist.c
static int __init CAMERA_HW_i2C_init(void)
{
....
if (platform_driver_register(&g_stCAMERA_HW_Driver)) //注册主摄platform 驱动
if (platform_driver_register(&g_stCAMERA_HW_Driver2)) //注册副摄platform 驱动
....
return 0;
}#ifdef CONFIG_OF
static const struct of_device_id CAMERA_HW_of_ids[] = {
{.compatible = "mediatek,camera_hw",}, //主摄匹配规则
{}
};
#endif
static struct platform_driver g_stCAMERA_HW_Driver = {
.probe = CAMERA_HW_probe,
.remove = CAMERA_HW_remove,
.suspend = CAMERA_HW_suspend,
.resume = CAMERA_HW_resume,
.driver = {
.name = "image_sensor",
.owner = THIS_MODULE,
#ifdef CONFIG_OF
.of_match_table = CAMERA_HW_of_ids,
#endif
}
};#ifdef CONFIG_OF
static const struct of_device_id CAMERA_HW2_of_ids[] = {
{.compatible = "mediatek,camera_hw2",},//副摄匹配规则
{}
};
#endif
static struct platform_driver g_stCAMERA_HW_Driver2 = {
.probe = CAMERA_HW_probe2,
.remove = CAMERA_HW_remove2,
.suspend = CAMERA_HW_suspend2,
.resume = CAMERA_HW_resume2,
.driver = {
.name = "image_sensor_bus2",
.owner = THIS_MODULE,
#ifdef CONFIG_OF
.of_match_table = CAMERA_HW2_of_ids,
#endif
}
};kd_camera_hw1:kd_camera_hw1@15008000 {
compatible = "mediatek,camera_hw"; //这里必须和主摄一致
reg = <0x15008000 0x1000>; /* SENINF_ADDR */
vcama-supply = <&mt_pmic_vcama_ldo_reg>;
vcamd-supply = <&mt_pmic_vcamd_ldo_reg>;
vcamaf-supply = <&mt_pmic_vcamaf_ldo_reg>;
vcamio-supply = <&mt_pmic_vcamio_ldo_reg>;
};
kd_camera_hw2:kd_camera_hw2@15008000 {
compatible = "mediatek,camera_hw2"; //这里必须和副摄一致
reg = <0x15008000 0x1000>; /* SENINF_ADDR */
};上面注册了两个platform 驱动g_stCAMERA_HW_Driver，g_stCAMERA_HW_Driver2，如果匹配成功会调用各自的
probe函数CAMERA_HW_probe，CAMERA_HW_probe2
2. 平台probe 函数的实现主摄probe，CAMERA_HW_probe的实现如下：
static int CAMERA_HW_probe(struct platform_device *pdev)
{
#if !defined(CONFIG_MTK_LEGACY)
mtkcam_gpio_init(pdev);
mtkcam_pin_mux_init(pdev);
#endif
return i2c_add_driver(&CAMERA_HW_i2c_driver);
}static int CAMERA_HW_probe2(struct platform_device *pdev)
{
return i2c_add_driver(&CAMERA_HW_i2c_driver2);
}CAMERA_HW_i2c_driver2， main sensor 的CAMERA_HW_i2c_driver定义如下：
#ifdef CONFIG_OF
static const struct of_device_id CAMERA_HW_i2c_of_ids[] = {
{ .compatible = "mediatek,camera_main", },
{}
};
#endif
struct i2c_driver CAMERA_HW_i2c_driver = {
.probe = CAMERA_HW_i2c_probe,
.remove = CAMERA_HW_i2c_remove,
.driver = {
.name = CAMERA_HW_DRVNAME1,
.owner = THIS_MODULE,
#ifdef CONFIG_OF
.of_match_table = CAMERA_HW_i2c_of_ids,
#endif
},
.id_table = CAMERA_HW_i2c_id,
};
sub sensor 的CAMERA_HW_i2c_driver定义如下：
#ifdef CONFIG_OF
static const struct of_device_id CAMERA_HW2_i2c_driver_of_ids[] = {
{ .compatible = "mediatek,camera_sub", },
{}
};
#endif
struct i2c_driver CAMERA_HW_i2c_driver2 = {
.probe = CAMERA_HW_i2c_probe2,
.remove = CAMERA_HW_i2c_remove2,
.driver = {
.name = CAMERA_HW_DRVNAME2,
.owner = THIS_MODULE,
#ifdef CONFIG_OF
.of_match_table = CAMERA_HW2_i2c_driver_of_ids,
#endif
},
.id_table = CAMERA_HW_i2c_id2,
};文件：kernel-3.18/arch/arm/boot/dts/cust_i2c.dtsi
&i2c0 {
camera_main@10 {
compatible = "mediatek,camera_main"; //和 CAMERA_HW_i2c_driver定义的一致
reg = <0x10>;
};
camera_main_af@0c {
compatible = "mediatek,camera_main_af";
reg = <0x0c>;
};
camera_sub@3c {
compatible = "mediatek,camera_sub"; //和CAMERA_HW_i2c_driver2定义的一致
reg = <0x3c>;
};
};从上可以看出main/sub sensor在各自的平台probe中，注册了i2c_driver,当各自的i2c_driver和设备匹配
（如何匹配本章不作分析）成功后，会调用各自的i2c_probe函数。main sensor 的probe函数
CAMERA_HW_i2c_probe：
static int CAMERA_HW_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
.....
/* Register char driver */
i4RetValue = RegisterCAMERA_HWCharDrv();
.....
return 0;
}static int CAMERA_HW_i2c_probe2(struct i2c_client *client, const struct i2c_device_id *id)
{
.....
/* Register char driver */
i4RetValue = RegisterCAMERA_HWCharDrv2();
.....
}static inline int RegisterCAMERA_HWCharDrv(void)//main sensor 注册cdev
{
.....
/* Attatch file operation. */
cdev_init(g_pCAMERA_HW_CharDrv, &g_stCAMERA_HW_fops); //初始化字符设备
/* Add to system */
cdev_add(g_pCAMERA_HW_CharDrv, g_CAMERA_HWdevno, 1) //注册到内核
//创建目录 /sys/class/sensordrv/
sensor_class = class_create(THIS_MODULE, "sensordrv");
//创建目录/sys/class/sensordrv/kd_camera_hw
sensor_device = device_create(sensor_class, NULL, g_CAMERA_HWdevno, NULL, CAMERA_HW_DRVNAME1);
....
return 0;
}
static inline int RegisterCAMERA_HWCharDrv2(void)//sub sensor 注册cdev
{
....
/* Attatch file operation. */
cdev_init(g_pCAMERA_HW_CharDrv2, &g_stCAMERA_HW_fops0);//初始化字符设备
/* Add to system */
cdev_add(g_pCAMERA_HW_CharDrv2, g_CAMERA_HWdevno2, 1));//注册到内核
//创建目录 /sys/class/sensordrv2/
sensor2_class = class_create(THIS_MODULE, "sensordrv2");
//创建目录/sys/class/sensordrv2/kd_camera_hw_bus2
sensor_device2 = device_create(sensor2_class, NULL, g_CAMERA_HWdevno2, NULL, CAMERA_HW_DRVNAME2);
....
return 0;
}
main/sub 创建各自的字符设备过程中绑定各自的fops,g_stCAMERA_HW_fops和g_stCAMERA_HW_fops0
他们各自定义如下
static const struct file_operations g_stCAMERA_HW_fops = { //main sensor fops
.owner = THIS_MODULE,
.open = CAMERA_HW_Open,
.release = CAMERA_HW_Release,
.unlocked_ioctl = CAMERA_HW_Ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = CAMERA_HW_Ioctl_Compat,
#endif
};
static const struct file_operations g_stCAMERA_HW_fops0 = { //sub sensor fops
.owner = THIS_MODULE,
.open = CAMERA_HW_Open2,
.release = CAMERA_HW_Release2,
.unlocked_ioctl = CAMERA_HW_Ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = CAMERA_HW_Ioctl_Compat,
#endif
};从上可以看出各自的fops指定了相同的Iioctl函数，意味着上层操作main/sub sensor 只需要对应一个底层
的ioctl即可，至于sensor的区分可以借助idx,后面会讲到
/*******************************************************************************
* CAMERA_HW_Ioctl
********************************************************************************/
static long CAMERA_HW_Ioctl(struct file *a_pstFile,
unsigned int a_u4Command, unsigned long a_u4Param)
{
...
pIdx = (u32 *) pBuff;
switch (a_u4Command) {
...
case KDIMGSENSORIOC_X_SET_DRIVER:
i4RetValue = kdSetDriver((unsigned int *)pBuff);
break;
case KDIMGSENSORIOC_X_FEATURECONCTROL:
i4RetValue = adopt_CAMERA_HW_FeatureControl(pBuff);
break;
case KDIMGSENSORIOC_T_CHECK_IS_ALIVE:
i4RetValue = adopt_CAMERA_HW_CheckIsAlive();
break;
....
default:
PK_DBG("No such command\n");
i4RetValue = -EPERM;
break;
}
.....
}============================== HAL 调用Kernel 层驱动的逻辑 ========================
前面介绍了HAL层调用ioctl 和 kernel层注册驱动，接下来继续分析，HAL层调用 后驱动 具体的实现流程。
4. ioctl 底层的实现
4.1先来看ioctl(m_fdSensor, KDIMGSENSORIOC_X_SET_DRIVER,&id[KDIMGSENSOR_INVOKE_DRIVER_0] );
当KDIMGSENSORIOC_X_SET_DRIVER被传下时，会调用kernel层的kdSetDriver接口
int kdSetDriver(unsigned int *pDrvIndex)
{
...
kdGetSensorInitFuncList(&pSensorList)) //获得sensor初始化列表
for (i = KDIMGSENSOR_INVOKE_DRIVER_0; i < KDIMGSENSOR_MAX_INVOKE_DRIVERS; i++) {
....
pSensorList[drvIdx[i]].SensorInit(&g_pInvokeSensorFunc[i]); //获取各个cam驱动中Init函数入口
....
}
return 0;
}UINT32 kdGetSensorInitFuncList(ACDK_KD_SENSOR_INIT_FUNCTION_STRUCT **ppSensorList)
{
if (NULL == ppSensorList) {
PK_ERR("[kdGetSensorInitFuncList]ERROR: NULL ppSensorList\n");
return 1;
}
*ppSensorList = &kdSensorList[0]; //获取sensorlist数组首地址
return 0;
} /* kdGetSensorInitFuncList() */
文件：kernel-3.18/drivers/misc/mediatek/imgsensor/src/mt6580/kd_sensorlist.h
ACDK_KD_SENSOR_INIT_FUNCTION_STRUCT kdSensorList[MAX_NUM_OF_SUPPORT_SENSOR+1] =
{
....
#if defined(SUB_GC2355_MIPI_RAW)
{GC2355S_SENSOR_ID, SENSOR_DRVNAME_GC2355S_MIPI_RAW,Sub_GC2355_MIPI_RAW_SensorInit},
#endif
....
}UINT32 GC2235MIPI_RAW_SensorInit(PSENSOR_FUNCTION_STRUCT *pfFunc)
{
/* To Do : Check Sensor status here */
if (pfFunc!=NULL)
*pfFunc=&sensor_func;
return ERROR_NONE;
} /* GC2235MIPI_RAW_SensorInit */丛中可以看出，gc2355的Init函数地址传给了pfFunc，也就是时候，后面在通用驱动可以直接凭借
pfun指针调用sensorlist中的驱动
4.2 再来看ioctl(m_fdSensor, KDIMGSENSORIOC_T_CHECK_IS_ALIVE);
当KDIMGSENSORIOC_T_CHECK_IS_ALIVE被传下时，会调用kernel层的adopt_CAMERA_HW_Feature
Control接口
static inline int adopt_CAMERA_HW_CheckIsAlive(void)
{
....
/* power on sensor */
kdModulePowerOn((CAMERA_DUAL_CAMERA_SENSOR_ENUM *) g_invokeSocketIdx, g_invokeSensorNameStr,
true, CAMERA_HW_DRVNAME1);
....
if (g_pSensorFunc) {
for (i = KDIMGSENSOR_INVOKE_DRIVER_0; i < KDIMGSENSOR_MAX_INVOKE_DRIVERS; i++) {
if (DUAL_CAMERA_NONE_SENSOR != g_invokeSocketIdx[i]) {
err =
g_pSensorFunc->SensorFeatureControl(g_invokeSocketIdx[i],
SENSOR_FEATURE_CHECK_SENSOR_ID,
(MUINT8 *) &sensorID,
&retLen);
if (sensorID == 0) { /* not implement this feature ID */
PK_DBG
(" Not implement!!, use old open function to check\n");
err = ERROR_SENSOR_CONNECT_FAIL;
} else if (sensorID == 0xFFFFFFFF) { /* fail to open the sensor */
PK_DBG(" No Sensor Found");
err = ERROR_SENSOR_CONNECT_FAIL;
} else {
PK_INF(" Sensor found ID = 0x%x\n", sensorID);
snprintf(mtk_ccm_name, sizeof(mtk_ccm_name),
"%s CAM[%d]:%s;", mtk_ccm_name,
g_invokeSocketIdx[i], g_invokeSensorNameStr[i]);
psensorResolution[0] = &sensorResolution[0];
psensorResolution[1] = &sensorResolution[1];
// don't care of the result
g_pSensorFunc->SensorGetResolution(psensorResolution);
if(g_invokeSocketIdx[i] == DUAL_CAMERA_MAIN_SENSOR)
curr_sensor_id = 0;
else if(g_invokeSocketIdx[i] == DUAL_CAMERA_SUB_SENSOR)
curr_sensor_id = 1;
/* fill the cam infos with name/width/height */
snprintf(g_cam_infos, sizeof(g_cam_infos),"%s CAM[%d]:%s,Width:%d, Height:%d;",
g_cam_infos, g_invokeSocketIdx[i], g_invokeSensorNameStr[i],
sensorResolution[curr_sensor_id].SensorFullWidth, sensorResolution[curr_sensor_id].SensorFullHeight);
err = ERROR_NONE;
}
if (ERROR_NONE != err) {
PK_DBG
("ERROR:adopt_CAMERA_HW_CheckIsAlive(), No imgsensor alive\n");
}
}
}
} else {
PK_DBG("ERROR:NULL g_pSensorFunc\n");
}
} /* adopt_CAMERA_HW_Open() */1）通过kdModulePowerOn给Sensor上电
2）通过SensorFeatureControl读取SensorID
先看kdModulePowerOn的实现
int
kdModulePowerOn(CAMERA_DUAL_CAMERA_SENSOR_ENUM socketIdx[KDIMGSENSOR_MAX_INVOKE_DRIVERS],
char sensorNameStr[KDIMGSENSOR_MAX_INVOKE_DRIVERS][32], BOOL On, char *mode_name)
{
MINT32 ret = ERROR_NONE;
u32 i = 0;
for (i = KDIMGSENSOR_INVOKE_DRIVER_0; i < KDIMGSENSOR_MAX_INVOKE_DRIVERS; i++) {
if (g_bEnableDriver[i]) {
/* PK_XLOG_INFO("[%s][%d][%d][%s][%s]\r\n",__FUNCTION__,g_bEnableDriver[i],socketIdx[i],sensorNameStr[i],mode_name); */
#ifndef CONFIG_FPGA_EARLY_PORTING
ret = _kdCISModulePowerOn(socketIdx[i], sensorNameStr[i], On, mode_name);
#endif
if (ERROR_NONE != ret) {
PK_ERR("[%s]", __func__);
return ret;
}
}
}
return ERROR_NONE;
}int _kdCISModulePowerOn(CAMERA_DUAL_CAMERA_SENSOR_ENUM SensorIdx, char *currSensorName, BOOL On,
char *mode_name)
{
....
ret = kdCISModulePowerOn(SensorIdx, currSensorName, On, mode_name);
....
return ret;
}文件：kernel-3.18/drivers/misc/mediatek/imgsensor/src/mt6580/camera_hw/kd_camera_hw.c
//改函数为上下电函数，通过传入BOOL值来判断上/下电
int kdCISModulePowerOn(CAMERA_DUAL_CAMERA_SENSOR_ENUM SensorIdx, char *currSensorName, BOOL On,
char *mode_name)
{
u32 pinSetIdx = 0; /* default main sensor */
#define IDX_PS_CMRST 0
#define IDX_PS_CMPDN 4
#define IDX_PS_MODE 1
#define IDX_PS_ON 2
#define IDX_PS_OFF 3
#define VOL_2800 2800000
#define VOL_1800 1800000
#define VOL_1500 1500000
#define VOL_1200 1200000
#define VOL_1000 1000000
u32 pinSet[3][8] = {
/* for main sensor */
{ /* The reset pin of main sensor uses GPIO10 of mt6306, please call mt6306 API to set */
CAMERA_CMRST_PIN,
CAMERA_CMRST_PIN_M_GPIO, /* mode */
GPIO_OUT_ONE, /* ON state */
GPIO_OUT_ZERO, /* OFF state */
CAMERA_CMPDN_PIN,
CAMERA_CMPDN_PIN_M_GPIO,
GPIO_OUT_ONE,
GPIO_OUT_ZERO,
},
/* for sub sensor */
{
CAMERA_CMRST1_PIN,
CAMERA_CMRST1_PIN_M_GPIO,
GPIO_OUT_ONE,
GPIO_OUT_ZERO,
CAMERA_CMPDN1_PIN,
CAMERA_CMPDN1_PIN_M_GPIO,
GPIO_OUT_ONE,
GPIO_OUT_ZERO,
},
/* for main_2 sensor */
{
GPIO_CAMERA_INVALID,
GPIO_CAMERA_INVALID, /* mode */
GPIO_OUT_ONE, /* ON state */
GPIO_OUT_ZERO, /* OFF state */
GPIO_CAMERA_INVALID,
GPIO_CAMERA_INVALID,
GPIO_OUT_ONE,
GPIO_OUT_ZERO,
}
};
if (DUAL_CAMERA_MAIN_SENSOR == SensorIdx)
pinSetIdx = 0;
else if (DUAL_CAMERA_SUB_SENSOR == SensorIdx)
pinSetIdx = 1;
else if (DUAL_CAMERA_MAIN_2_SENSOR == SensorIdx)
pinSetIdx = 2;
/* power ON */
if (On) {
#if 0
ISP_MCLK1_EN(1);
ISP_MCLK2_EN(1);
ISP_MCLK3_EN(1);
#else
if (pinSetIdx == 0)
ISP_MCLK1_EN(1);
else if (pinSetIdx == 1)
ISP_MCLK2_EN(1);
#endif
printk("fangkuiccm %d ,currSensorName = %s pinSetIdx = %d ",__LINE__,currSensorName,pinSetIdx );
//通过DriverName来区分SensorIC
if (currSensorName && (0 == strcmp(SENSOR_DRVNAME_GC2355_MIPI_RAW, currSensorName))) {
/* First Power Pin low and Reset Pin Low */
if (GPIO_CAMERA_INVALID != pinSet[pinSetIdx][IDX_PS_CMPDN])
mtkcam_gpio_set(pinSetIdx, CAMPDN,
pinSet[pinSetIdx][IDX_PS_CMPDN + IDX_PS_OFF]);
if (GPIO_CAMERA_INVALID != pinSet[pinSetIdx][IDX_PS_CMRST])
mtkcam_gpio_set(pinSetIdx, CAMRST,
pinSet[pinSetIdx][IDX_PS_CMRST + IDX_PS_OFF]);
mdelay(50);
/* VCAM_A */
if (TRUE != _hwPowerOn(VCAMA, VOL_2800)) {
PK_DBG
("[CAMERA SENSOR] Fail to enable analog power (VCAM_A),power id = %d\n",
VCAMA);
goto _kdCISModulePowerOn_exit_;
}
mdelay(10);
/* VCAM_IO */
if (TRUE != _hwPowerOn(VCAMIO, VOL_1800)) {
PK_DBG
("[CAMERA SENSOR] Fail to enable IO power (VCAM_IO),power id = %d\n",
VCAMIO);
goto _kdCISModulePowerOn_exit_;
}
mdelay(10);
if (TRUE != _hwPowerOn(VCAMD, VOL_1500)) {
PK_DBG
("[CAMERA SENSOR] Fail to enable digital power (VCAM_D),power id = %d\n",
VCAMD);
goto _kdCISModulePowerOn_exit_;
}
mdelay(10);
/* AF_VCC */
if (TRUE != _hwPowerOn(VCAMAF, VOL_2800)) {
PK_DBG
("[CAMERA SENSOR] Fail to enable analog power (VCAM_AF),power id = %d\n",
VCAMAF);
goto _kdCISModulePowerOn_exit_;
}
mdelay(50);
if (GPIO_CAMERA_INVALID != pinSet[pinSetIdx][IDX_PS_CMRST]) {
mtkcam_gpio_set(pinSetIdx, CAMRST,
pinSet[pinSetIdx][IDX_PS_CMRST + IDX_PS_OFF]);
mdelay(5);
mtkcam_gpio_set(pinSetIdx, CAMRST,
pinSet[pinSetIdx][IDX_PS_CMRST + IDX_PS_ON]);
}
mdelay(5);
/* enable active sensor */
if (GPIO_CAMERA_INVALID != pinSet[pinSetIdx][IDX_PS_CMPDN]) {
mtkcam_gpio_set(pinSetIdx, CAMPDN,
pinSet[pinSetIdx][IDX_PS_CMPDN + IDX_PS_ON]);
mdelay(5);
mtkcam_gpio_set(pinSetIdx, CAMPDN,
pinSet[pinSetIdx][IDX_PS_CMPDN + IDX_PS_OFF]);
}
mdelay(5);
}
}else{ //poweroff
if (currSensorName //上完电就要下电不然会造成漏电，最终会影响手机功耗
&& (0 == strcmp(SENSOR_DRVNAME_GC2355_MIPI_RAW, currSensorName))) {
#if 0
mt_set_gpio_mode(GPIO_SPI_MOSI_PIN, GPIO_MODE_00);
mt_set_gpio_dir(GPIO_SPI_MOSI_PIN, GPIO_DIR_OUT);
mt_set_gpio_out(GPIO_SPI_MOSI_PIN, GPIO_OUT_ONE);
#endif
/* First Power Pin low and Reset Pin Low */
if (GPIO_CAMERA_INVALID != pinSet[pinSetIdx][IDX_PS_CMPDN]) {
if (mt_set_gpio_mode
(pinSet[pinSetIdx][IDX_PS_CMPDN],
pinSet[pinSetIdx][IDX_PS_CMPDN + IDX_PS_MODE])) {
PK_DBG("[CAMERA LENS] set gpio mode failed!! (CMPDN)\n");
}
if (mt_set_gpio_dir(pinSet[pinSetIdx][IDX_PS_CMPDN], GPIO_DIR_OUT)) {
PK_DBG("[CAMERA LENS] set gpio dir failed!! (CMPDN)\n");
}
if (mt_set_gpio_out
(pinSet[pinSetIdx][IDX_PS_CMPDN],
pinSet[pinSetIdx][IDX_PS_CMPDN + IDX_PS_OFF])) {
PK_DBG("[CAMERA LENS] set gpio failed!! (CMPDN)\n");
}
}
}
}g_pSensorFunc->SensorFeatureControl(g_invokeSocketIdx[i],
SENSOR_FEATURE_CHECK_SENSOR_ID,
(MUINT8 *) &sensorID,
&retLen);
这步操作会调用GC2355中的feature_control函数如下：
文件：kernel-3.18/drivers/misc/mediatek/imgsensor/src/mt6580/gc2355_mipi_raw/gc2355mipi_Sensor.c
static kal_uint32 feature_control(MSDK_SENSOR_FEATURE_ENUM feature_id,
UINT8 *feature_para,UINT32 *feature_para_len)
{
....
LOG_INF("feature_id = %d\n", feature_id);
switch (feature_id) {
....
case SENSOR_FEATURE_CHECK_SENSOR_ID:
get_imgsensor_id(feature_return_para_32);
break;
....
default:
break;
}
return ERROR_NONE;
} 优化传入的cmd为SENSOR_FEATURE_CHECK_SENSOR_ID，则会调用feature_control中的
get_imgsensor_id再看get_imgsensor_id的实现
static kal_uint32 get_imgsensor_id(UINT32 *sensor_id)
{
kal_uint8 i = 0;
kal_uint8 retry = 2;
//sensor have two i2c address 0x6c 0x6d & 0x21 0x20, we should detect the module used i2c address
while (imgsensor_info.i2c_addr_table[i] != 0xff) {
spin_lock(&imgsensor_drv_lock);
imgsensor.i2c_write_id = imgsensor_info.i2c_addr_table[i];
spin_unlock(&imgsensor_drv_lock);
do {
*sensor_id = return_sensor_id(); //return_sensor_id读取IC的ID
if (*sensor_id == imgsensor_info.sensor_id) {
LOG_INF("i2c write id: 0x%x, sensor id: 0x%x\n", imgsensor.i2c_write_id,*sensor_id);
return ERROR_NONE;
}
LOG_INF("Read sensor id fail, write id: 0x%x, id: 0x%x\n", imgsensor.i2c_write_id,*sensor_id);
retry--;
} while(retry > 0);
i++;
retry = 2;
}
....
return ERROR_NONE;
}static kal_uint32 return_sensor_id(void)
{
return ((read_cmos_sensor(0xf0) << 8) | read_cmos_sensor(0xf1));
}
static kal_uint16 read_cmos_sensor(kal_uint32 addr)
{
kal_uint16 get_byte=0;
char pu_send_cmd[1] = {(char)(addr & 0xFF) };
iReadRegI2C(pu_send_cmd, 1, (u8*)&get_byte, 1, imgsensor.i2c_write_id);
return get_byte;
}int iReadRegI2C(u8 *a_pSendData, u16 a_sizeSendData, u8 *a_pRecvData, u16 a_sizeRecvData,
u16 i2cId)
{
int i4RetValue = 0;
if (gI2CBusNum == SUPPORT_I2C_BUS_NUM1) {
spin_lock(&kdsensor_drv_lock);
g_pstI2Cclient->addr = (i2cId >> 1);
g_pstI2Cclient->ext_flag = (g_pstI2Cclient->ext_flag) & (~I2C_DMA_FLAG);
/* Remove i2c ack error log during search sensor */
/* PK_ERR("g_pstI2Cclient->ext_flag: %d", g_IsSearchSensor); */
if (g_IsSearchSensor == 1) {
g_pstI2Cclient->ext_flag = (g_pstI2Cclient->ext_flag) | I2C_A_FILTER_MSG;
} else {
g_pstI2Cclient->ext_flag = (g_pstI2Cclient->ext_flag) & (~I2C_A_FILTER_MSG);
}
spin_unlock(&kdsensor_drv_lock);
/* */
i4RetValue = i2c_master_send(g_pstI2Cclient, a_pSendData, a_sizeSendData);
if (i4RetValue != a_sizeSendData) {
PK_ERR("[CAMERA SENSOR] I2C send failed!!, Addr = 0x%x\n", a_pSendData[0]);
return -1;
}
i4RetValue = i2c_master_recv(g_pstI2Cclient, (char *)a_pRecvData, a_sizeRecvData);
if (i4RetValue != a_sizeRecvData) {
PK_ERR("[CAMERA SENSOR] I2C read failed!!\n");
return -1;
}
} else {
spin_lock(&kdsensor_drv_lock);
g_pstI2Cclient2->addr = (i2cId >> 1);
/* Remove i2c ack error log during search sensor */
/* PK_ERR("g_pstI2Cclient2->ext_flag: %d", g_IsSearchSensor); */
if (g_IsSearchSensor == 1) {
g_pstI2Cclient2->ext_flag = (g_pstI2Cclient2->ext_flag) | I2C_A_FILTER_MSG;
} else {
g_pstI2Cclient2->ext_flag = (g_pstI2Cclient2->ext_flag) & (~I2C_A_FILTER_MSG);
}
spin_unlock(&kdsensor_drv_lock);
i4RetValue = i2c_master_send(g_pstI2Cclient2, a_pSendData, a_sizeSendData);
if (i4RetValue != a_sizeSendData) {
PK_ERR("[CAMERA SENSOR] I2C send failed!!, Addr = 0x%x\n", a_pSendData[0]);
return -1;
}
i4RetValue = i2c_master_recv(g_pstI2Cclient2, (char *)a_pRecvData, a_sizeRecvData);
if (i4RetValue != a_sizeRecvData) {
PK_ERR("[CAMERA SENSOR] I2C read failed!!\n");
return -1;
}
}
return 0;
}这一步完成I2c的读取，也就是说如果I2c配置正确，并且上电正确，到这一步就可以正确的读取ID，
整个camera也就基本就调通了。
三、总结
通过上述分析，我们可以看出，camera驱动先是注册平台驱动，再注册I2c驱动，然后又为前后摄
注册字符设备，封装底层方法，上层访问底层驱动时候显示使用setdriver将具体IC的驱动入口获取，
然后使用checkisalive对sensorlist中的IC进行上电，上电完成就读取设备ID，到此为止，上层应用与
底层驱动挂接完成，紧接着就是预览和拍照，不过这都是具体IC驱动的实现了。