1# MIPI CSI 2 3## Overview 4 5The Camera Serial Interface (CSI), defined by the Mobile Industry Processor Interface (MIPI) Alliance, allows data to be transmitted from the camera to the host processor on mobile platforms. In the Hardware Driver Foundation (HDF), the MIPI CSI module uses the service-free mode for API adaptation. The service-free mode applies to the devices that do not provide user-mode APIs or the operating system (OS) that does not distinguish the user mode and the kernel mode. In the service-free mode, **DevHandle** (a void pointer) directly points to the kernel-mode address of the device object. 6 7**Figure 1** Service-free mode 8 9 10 11## Available APIs 12 13**MipiCsiCntlrMethod**: 14 15```c 16struct MipiCsiCntlrMethod { 17 int32_t (*setComboDevAttr)(struct MipiCsiCntlr *cntlr, ComboDevAttr *pAttr); 18 int32_t (*setPhyCmvmode)(struct MipiCsiCntlr *cntlr, uint8_t devno, PhyCmvMode cmvMode); 19 int32_t (*setExtDataType)(struct MipiCsiCntlr *cntlr, ExtDataType* dataType); 20 int32_t (*setHsMode)(struct MipiCsiCntlr *cntlr, LaneDivideMode laneDivideMode); 21 int32_t (*enableClock)(struct MipiCsiCntlr *cntlr, uint8_t comboDev); 22 int32_t (*disableClock)(struct MipiCsiCntlr *cntlr, uint8_t comboDev); 23 int32_t (*resetRx)(struct MipiCsiCntlr *cntlr, uint8_t comboDev); 24 int32_t (*unresetRx)(struct MipiCsiCntlr *cntlr, uint8_t comboDev); 25 int32_t (*enableSensorClock)(struct MipiCsiCntlr *cntlr, uint8_t snsClkSource); 26 int32_t (*disableSensorClock)(struct MipiCsiCntlr *cntlr, uint8_t snsClkSource); 27 int32_t (*resetSensor)(struct MipiCsiCntlr *cntlr, uint8_t snsResetSource); 28 int32_t (*unresetSensor)(struct MipiCsiCntlr *cntlr, uint8_t snsResetSource); 29}; 30``` 31**Table 1** Description of the callback functions in the MipiCsiCntlrMethod structure 32| Function | Input Parameter | Output Parameter| Return Value | Description | 33| ------------------ | ------------------------------------------------------------ | ---- | ------------------ | -------------------------- | 34| setComboDevAttr | **cntlr**: structure pointer to the MIPI CSI controller.<br>**pAttr**: structure pointer to the MIPI CSI configuration.| – | HDF_STATUS| Sets MIPI CSI attributes. | 35| setPhyCmvmode | **cntlr**: structure pointer to the MIPI CSI controller.<br>**devno**: Device number, which is of the uint8_t type.<br>**cmvMode**: common-mode voltage (CMV) mode to set.| – | HDF_STATUS| Sets the CMV mode. | 36| setExtDataType | **cntlr**: structure pointer to the MIPI CSI controller.<br>**dataType**: structure pointer to the data that defines the YUV, original data formats, and bit depth.| – | HDF_STATUS| Sets the YUV, RAW data format, and bit depth.| 37| setHsMode | **cntlr**: structure pointer to the MIPI CSI controller.<br>**laneDivideMode**: lane mode.| – | HDF_STATUS| Sets the MIPI RX lane distribution. | 38| enableClock | **cntlr**: structure pointer to the MIPI CSI controller.<br>**comboDev**: channel number, which is of the uint8_t type.| – | HDF_STATUS| Enables the MIPI clock. | 39| disableClock | **cntlr**: structure pointer to the MIPI CSI controller.<br>**comboDev**: channel number, which is of the uint8_t type.| – | HDF_STATUS| Disables the MIPI clock. | 40| resetRx | **cntlr**: structure pointer to the MIPI CSI controller.<br>**comboDev**: channel number, which is of the uint8_t type.| – | HDF_STATUS| Resets the MIPI RX. | 41| unresetRx | **cntlr**: structure pointer to the MIPI CSI controller.<br>**comboDev**: channel number, which is of the uint8_t type.| – | HDF_STATUS| Deasserts the reset of the MIPI RX. | 42| enableSensorClock | **cntlr**: structure pointer to the MIPI CSI controller.<br>**snsClkSource**: number of the clock signal cable of the sensor, which is of the uint8_t type.| – | HDF_STATUS| Enables the MIPI sensor clock. | 43| disableSensorClock | **cntlr**: structure pointer to the MIPI CSI controller.<br>**snsClkSource**: number of the clock signal cable of the sensor, which is of the uint8_t type.| – | HDF_STATUS| Disables the MIPI sensor clock. | 44| resetSensor | **cntlr**: structure pointer to the MIPI CSI controller.<br>**snsClkSource**: number of the clock signal cable of the sensor, which is of the uint8_t type.| – | HDF_STATUS| Resets a sensor. | 45| unresetSensor | **cntlr**: structure pointer to the MIPI CSI controller.<br>**snsClkSource**: number of the clock signal cable of the sensor, which is of the uint8_t type.| – | HDF_STATUS| Deasserts the reset of a sensor. | 46 47## How to Develop 48 49The MIPI CSI module adaptation involves the following steps: 50 511. Configure attribute files. 52 53 - Add the **deviceNode** information to the **device_info.hcs** file. 54 - (Optional) Add the **mipicsi_config.hcs** file. 55 562. Instantiate the driver entry. 57 58 - Instantiate the **HdfDriverEntry** structure. 59 - Call **HDF_INIT** to register the **HdfDriverEntry** instance with the HDF. 60 613. Instantiate the MIPI CSI controller object. 62 63 - Initialize **MipiCsiCntlr**. 64 - Instantiate **MipiCsiCntlrMethod** in the **MipiCsiCntlr** object. 65 > **NOTE**<br> 66 >For details about the functions in **MipiCsiCntlrMethod**, see [Available APIs](#available-apis). 67 684. Debug the driver. 69 70 (Optional) For new drivers, verify the basic functions, for example, the data transmission and the information returned after the **MipiCsiCntlrMethod** instance is attached. 71 72 73## Development Example 74 75The following uses **mipi_rx_hi35xx.c** as an example to present the information required for implementing device functions. 76 77 781. Configure the device attributes in **busxx_config.hcs** and add the **deviceNode** information to the **device_info.hcs** file. 79 80 The device attribute values are closely related to the default values or value range of the **MipiCsiCntlr** members at the core layer. The **deviceNode** information is related to the driver entry registration. 81 82 > **NOTE**<br> 83 >In this example, the MIPI controller attributes are defined in the source file. If required, add the **deviceMatchAttr** information to **deviceNode** in the **device_info** file and add the **mipicsi_config.hcs** file. 84 85 - **device_info.hcs** configuration example 86 87 ```c 88 root { 89 device_info { 90 match_attr = "hdf_manager"; 91 platform :: host { 92 hostName = "platform_host"; 93 priority = 50; 94 device_mipi_csi:: device { 95 device0 :: deviceNode { 96 policy = 0; 97 priority = 160; 98 permission = 0644; 99 moduleName = "HDF_MIPI_RX"; // (Mandatory) Driver name, which must be the same as moduleName in the driver entry. 100 serviceName = "HDF_MIPI_RX"; // (Mandatory) Unique name of the service published by the driver. 101 } 102 } 103 } 104 } 105 } 106 ``` 107 108 1092. Instantiate the driver entry. 110 111 The driver entry must be a global variable of the **HdfDriverEntry** type (defined in **hdf_device_desc.h**), and the value of **moduleName** must be the same as that in **device_info.hcs**. The function pointer members in the **HdfDriverEntry** structure are filled by the vendors' operation functions. In the HDF, the start address of each **HdfDriverEntry** object of all loaded drivers is collected to form a segment address space similar to an array for the upper layer to invoke. 112 113 Generally, the HDF calls the **Bind** function and then the **Init** function to load a driver. If **Init** fails to be called, the HDF calls **Release** to release driver resources and exit. 114 115 - MIPI CSI driver entry example 116 117 ```c 118 struct HdfDriverEntry g_mipiCsiDriverEntry = { 119 .moduleVersion = 1, 120 .Init = Hi35xxMipiCsiInit, // See the Init function. 121 .Release = Hi35xxMipiCsiRelease, // See the Release function. 122 .moduleName = "HDF_MIPI_RX", // (Mandatory) The value must be the same as that in the device_info.hcs file. 123 }; 124 HDF_INIT(g_mipiCsiDriverEntry); // Call HDF_INIT to register the driver entry with the HDF. 125 ``` 126 127 128 1293. Initialize the **MipiCsiCntlr** object at the core layer, including defining a custom structure (to pass parameters and data) and implementing the **HdfDriverEntry** member functions (**Bind**, **Init**, and **Release**) to instantiate **MipiCsiCntlrMethod** in **MipiCsiCntlr** (so that the underlying driver functions can be called). 130 131 - Defining a custom structure 132 133 To the driver, the custom structure holds parameters and data. The values in the **config** file are used to initialize the structure members. In this example, the MIPI CSI attributes are defined in the source file. Therefore, the basic member structure is similar to that of **MipiCsiCntlr**. 134 135 ```c 136 typedef struct { 137 /** The data type can be 8-, 10-, 12-, 14-, or 16-bit. */ 138 DataType inputDataType; 139 /** MIPI WDM mode */ 140 MipiWdrMode wdrMode; 141 /** laneId: -1 - disabled */ 142 short laneId[MIPI_LANE_NUM]; 143 144 union { 145 /** Used for HI_MIPI_WDR_MODE_DT */ 146 short dataType[WDR_VC_NUM]; 147 }; 148 } MipiDevAttr; 149 150 typedef struct { 151 /** Device number */ 152 uint8_t devno; 153 /** Input mode, which can be MIPI, LVDS, sub-LVDS, HiSPi, or DC. */ 154 InputMode inputMode; 155 MipiDataRate dataRate; 156 /** Crop area of the MIPI RX device (same as the size of the sensor input image) */ 157 ImgRect imgRect; 158 159 union { 160 MipiDevAttr mipiAttr; 161 LvdsDevAttr lvdsAttr; 162 }; 163 } ComboDevAttr; 164 165 // MipiCsiCntlr is the core layer controller structure. The Init function assigns values to the members of MipiCsiCntlr. 166 struct MipiCsiCntlr { 167 /** Send the service provided by this controller when the driver is bound to the HDF. */ 168 struct IDeviceIoService service; 169 /** Pass the pointer to the device when the driver is bound to the HDF. */ 170 struct HdfDeviceObject *device; 171 /** Device number */ 172 unsigned int devNo; 173 /** All APIs provided by the controller */ 174 struct MipiCsiCntlrMethod *ops; 175 /** All APIs for controller debugging. Set it to null if the driver is not implemented. */ 176 struct MipiCsiCntlrDebugMethod *debugs; 177 /** Controller context variable. */ 178 MipiDevCtx ctx; 179 /** Spinlock used when the controller context variable is accessed. */ 180 OsalSpinlock ctxLock; 181 /** Lock method when the controller is managed */ 182 struct OsalMutex lock; 183 /** Pointer to the anonymous structure that holds the CSI device data */ 184 void *priv; 185 }; 186 ``` 187 188 - Instantiating **MipiCsiCntlrMethod** in **MipiCsiCntlr** 189 190 > 191 > 192 >Other members are initialized by **Init**. 193 194 195 ```c 196 static struct MipiCsiCntlrMethod g_method = { 197 .setComboDevAttr = Hi35xxSetComboDevAttr, 198 .setPhyCmvmode = Hi35xxSetPhyCmvmode, 199 .setExtDataType = Hi35xxSetExtDataType, 200 .setHsMode = Hi35xxSetHsMode, 201 .enableClock = Hi35xxEnableClock, 202 .disableClock = Hi35xxDisableClock, 203 .resetRx = Hi35xxResetRx, 204 .unresetRx = Hi35xxUnresetRx, 205 .enableSensorClock = Hi35xxEnableSensorClock, 206 .disableSensorClock = Hi35xxDisableSensorClock, 207 .resetSensor = Hi35xxResetSensor, 208 .unresetSensor = Hi35xxUnresetSensor 209 }; 210 ``` 211 212 - **Init** function 213 214 **Input parameter**: 215 216 **HdfDeviceObject**, an interface parameter exposed by the driver, contains the .hcs information. 217 218 **Return value**: 219 220 **HDF_STATUS**<br/>The table below describes some status. For more information, see **HDF_STATUS** in the **/drivers/framework/include/utils/hdf_base.h** file. 221 222 | Status | Description | 223 | :--------------------- | :------------------------: | 224 | HDF_ERR_INVALID_OBJECT | Invalid object. | 225 | HDF_ERR_MALLOC_FAIL | Failed to allocate memory. | 226 | HDF_ERR_INVALID_PARAM | Invalid parameter. | 227 | HDF_ERR_IO | I/O error. | 228 | HDF_SUCCESS | Operation successful. | 229 | HDF_FAILURE | Operation failed. | 230 231 **Function description**: 232 233 Attaches the **MipiCsiCntlrMethod** instance, calls **MipiCsiRegisterCntlr**, and initializes the custom structure. 234 235 ```c 236 static int32_t Hi35xxMipiCsiInit(struct HdfDeviceObject *device) 237 { 238 int32_t ret; 239 240 HDF_LOGI("%s: enter!", __func__); 241 g_mipiCsi.priv = NULL; // g_mipiTx is a global variable defined. 242 // static struct MipiCsiCntlr g_mipiCsi = { 243 // .devNo = 0 244 //}; 245 g_mipiCsi.ops = &g_method; // Attach the MipiCsiCntlrMethod instance. 246 #ifdef CONFIG_HI_PROC_SHOW_SUPPORT 247 g_mipiCsi.debugs = &g_debugMethod; 248 #endif 249 ret = MipiCsiRegisterCntlr(&g_mipiCsi, device); // (Mandatory) Call the function at the core layer and g_mipiTx to initialize global variables at the core layer. 250 if (ret != HDF_SUCCESS) { 251 HDF_LOGE("%s: [MipiCsiRegisterCntlr] failed!", __func__); 252 return ret; 253 } 254 255 ret = MipiRxDrvInit(); // (Mandatory) Device initialization customized by the vendor. 256 if (ret != HDF_SUCCESS) { 257 HDF_LOGE("%s: [MipiRxDrvInit] failed.", __func__); 258 return ret; 259 } 260 #ifdef MIPICSI_VFS_SUPPORT 261 ret = MipiCsiDevModuleInit(g_mipiCsi.devNo); 262 if (ret != HDF_SUCCESS) { 263 HDF_LOGE("%s: [MipiCsiDevModuleInit] failed!", __func__); 264 return ret; 265 } 266 #endif 267 268 OsalSpinInit(&g_mipiCsi.ctxLock); 269 HDF_LOGI("%s: load mipi csi driver success!", __func__); 270 271 return ret; 272 } 273 274 // mipi_csi_core.c file 275 int32_t MipiCsiRegisterCntlr(struct MipiCsiCntlr *cntlr, struct HdfDeviceObject *device) 276 { 277 ... 278 // Global variable static struct MipiCsiHandle g_mipiCsihandle[MAX_CNTLR_CNT]; 279 if (g_mipiCsihandle[cntlr->devNo].cntlr == NULL) { 280 (void)OsalMutexInit(&g_mipiCsihandle[cntlr->devNo].lock); 281 (void)OsalMutexInit(&(cntlr->lock)); 282 283 g_mipiCsihandle[cntlr->devNo].cntlr = cntlr; // Initialize MipiCsiHandle. 284 g_mipiCsihandle[cntlr->devNo].priv = NULL; 285 cntlr->device = device; // Prerequisites for conversion between HdfDeviceObject and MipiCsiHandle 286 device->service = &(cntlr->service); // Prerequisites for conversion between HdfDeviceObject and MipiCsiHandle. 287 cntlr->priv = NULL; 288 HDF_LOGI("%s: success.", __func__); 289 290 return HDF_SUCCESS; 291 } 292 293 HDF_LOGE("%s: cntlr already exists.", __func__); 294 return HDF_FAILURE; 295 } 296 ``` 297 298 299 300 301 - **Release** function 302 303 **Input parameter**: 304 305 **HdfDeviceObject**, an interface parameter exposed by the driver, contains the .hcs information. 306 307 **Return value**: 308 309 No value is returned. 310 311 **Function description**: 312 313 Releases the memory and deletes the controller. This function assigns values to the **Release** API in the driver entry structure. When the HDF fails to call the **Init** function to initialize the driver, the **Release** function can be called to release driver resources. 314 315 > **NOTE** 316 > 317 >All forced conversion operations for obtaining the corresponding object can be successful only when the **Init** function has the value assignment operations. 318 319 ```c 320 static void Hi35xxMipiCsiRelease(struct HdfDeviceObject *device) 321 { 322 struct MipiCsiCntlr *cntlr = NULL; 323 ... 324 cntlr = MipiCsiCntlrFromDevice(device); // A forced conversion from HdfDeviceObject to MipiCsiCntlr is involved. 325 // return (device == NULL) ? NULL : (struct MipiCsiCntlr *)device->service; 326 ... 327 328 OsalSpinDestroy(&cntlr->ctxLock); 329 #ifdef MIPICSI_VFS_SUPPORT 330 MipiCsiDevModuleExit(cntlr->devNo); 331 #endif 332 MipiRxDrvExit(); // (Mandatory) Release the resources occupied by vendor devices. 333 MipiCsiUnregisterCntlr(&g_mipiCsi); // Null function 334 g_mipiCsi.priv = NULL; 335 336 HDF_LOGI("%s: unload mipi csi driver success!", __func__); 337 } 338 ``` 339 340 341 342 343 344
