In the Hardware Driver Foundation (HDF), the MultiMedia Card (MMC) uses the independent service mode for API adaptation. In this mode, each device independently publishes a service to process external access requests. When receiving an access request, the HDF DeviceManager extracts parameters from the request to call the internal APIs of the target device. In the independent service mode, the HDF DeviceManager provides service management capabilities. However, you need to configure a node for each device, which increases memory usage.
In the Hardware Driver Foundation (HDF), the MultiMedia Card (MMC) uses the independent service mode for API adaptation. In this mode, each device independently publishes a service to process external access requests. When receiving an access request, the HDF DeviceManager extracts parameters from the request to call the internal APIs of the target device. In the independent service mode, the HDF DeviceManager provides service management capabilities. However, you need to configure a node for each device, which increases memory usage.
**Figure 1** Independent service mode
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@@ -14,7 +14,7 @@ In the Hardware Driver Foundation (HDF), the MultiMedia Card (MMC) uses the inde
| doRequest | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**cmd**: structure pointer to the command to execute.| HDF_STATUS| Processes the request.|
| setClock | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**clock**: clock frequency to set.| HDF_STATUS| Sets the clock frequency.|
| setPowerMode | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**mode**: power consumption mode, which is an enumerated value.| HDF_STATUS| Sets the power consumption mode.|
| setBusWidth | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**width**: bus width, which is an enumerated value.| HDF_STATUS| Sets the bus width.|
| setBusTiming | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**timing**: bus timing, which is an enumerated value.| HDF_STATUS| Sets the bus timing.|
| setSdioIrq | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**enable**: whether to enable Secure Digital Input Output (SDIO) interrupts.| HDF_STATUS| Enables or disables SDIO interrupts.|
| hardwareReset | **cntlr**: structure pointer to the MMC controller at the core layer.| HDF_STATUS| Resets hardware.|
| systemInit | **cntlr**: structure pointer to the MMC controller at the core layer.| HDF_STATUS| Performs system initialization.|
| setEnhanceSrobe | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**enable**: whether to enable the enhanced strobe feature.| HDF_STATUS| Sets the enhanced strobe feature.|
| switchVoltage | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**volt**: voltage to set, which can be 3.3 V, 1.8 V, or 1.2 V.| HDF_STATUS| Sets the voltage.|
| devReadOnly | **cntlr**: structure pointer to the MMC controller at the core layer.| Boolean value| Checks whether the device is read-only.|
| cardPluged | **cntlr**: structure pointer to the MMC controller at the core layer.| Boolean value| Checks whether the device is removed.|
| devBusy | **cntlr**: structure pointer to the MMC controller at the core layer.| Boolean value| Checks whether the device is being used.|
| tune | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**cmdCode**: command code of the uint32_t type.| HDF_STATUS| Tunes the oscillator circuit frequency. |
| rescanSdioDev | **cntlr**: structure pointer to the MMC controller at the core layer.| HDF_STATUS| Scans and adds an SDIO device.|
| doRequest | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**cmd**: structure pointer to the command to execute.| HDF_STATUS| Processes the request.|
| setClock | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**clock**: clock frequency to set.| HDF_STATUS| Sets the clock frequency.|
| setPowerMode | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**mode**: power consumption mode, which is an enumerated value.| HDF_STATUS| Sets the power consumption mode.|
| setBusWidth | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**width**: bus width, which is an enumerated value.| HDF_STATUS| Sets the bus width.|
| setBusTiming | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**timing**: bus timing, which is an enumerated value.| HDF_STATUS| Sets the bus timing.|
| setSdioIrq | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**enable**: whether to enable Secure Digital Input Output (SDIO) interrupts.| HDF_STATUS| Enables or disables SDIO interrupts.|
| hardwareReset | **cntlr**: structure pointer to the MMC controller at the core layer.| HDF_STATUS| Resets hardware.|
| systemInit | **cntlr**: structure pointer to the MMC controller at the core layer.| HDF_STATUS| Performs system initialization.|
| setEnhanceSrobe | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**enable**: whether to enable the enhanced strobe feature.| HDF_STATUS| Sets the enhanced strobe feature.|
| switchVoltage | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**volt**: voltage to set, which can be 3.3 V, 1.8 V, or 1.2 V.| HDF_STATUS| Sets the voltage.|
| devReadOnly | **cntlr**: structure pointer to the MMC controller at the core layer.| Boolean value| Checks whether the device is read-only.|
| cardPluged | **cntlr**: structure pointer to the MMC controller at the core layer.| Boolean value| Checks whether the device is removed.|
| devBusy | **cntlr**: structure pointer to the MMC controller at the core layer.| Boolean value| Checks whether the device is being used.|
| tune | **cntlr**: structure pointer to the MMC controller at the core layer.<br>**cmdCode**: command code of the uint32_t type.| HDF_STATUS| Tunes the oscillator circuit frequency.|
| rescanSdioDev | **cntlr**: structure pointer to the MMC controller at the core layer.| HDF_STATUS| Scans and adds an SDIO device.|
## How to Develop
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@@ -75,7 +75,6 @@ The MMC module adaptation involves the following steps:
> For details about the functions in **MmcCntlrOps**, see [Available APIs](#available-apis).
4. Debug the driver.
(Optional) For new drivers, verify the basic functions, for example, check the information returned after the **MmcCntlrOps** instance is attached and whether the device starts successfully.
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@@ -88,7 +87,7 @@ The following uses **himci.c** as an example to present the information required
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.
MMC driver entry example:
```
struct HdfDriverEntry g_mmcDriverEntry = {
.moduleVersion = 1,
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@@ -106,7 +105,7 @@ The following uses **himci.c** as an example to present the information required
-**device_info.hcs** configuration example
```
root {
device_info {
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@@ -147,7 +146,7 @@ The following uses **himci.c** as an example to present the information required
-**mmc_config.hcs** configuration example
```
root {
platform {
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@@ -196,15 +195,15 @@ The following uses **himci.c** as an example to present the information required
}
}
}
}
```
}
```
3. Initialize the **MmcCntlr** 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 **MmcCntlrOps** in **MmcCntlr** (so that the underlying driver functions can be called).
- Defining a custom structure
To the driver, the custom structure holds parameters and data. The **DeviceResourceIface** method provided by the HDF reads the values in the **mmc_config.hcs** file to initialize the members in the custom structure and passes important parameters to the **MmcCntlr** object at the core layer.
@@ -257,7 +256,7 @@ The following uses **himci.c** as an example to present the information required
- Instantiating **MmcCntlrOps** in **MmcCntlr** (other members are initialized by **Bind**)
```
static struct MmcCntlrOps g_himciHostOps = {
.request = HimciDoRequest,
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@@ -300,7 +299,7 @@ The following uses **himci.c** as an example to present the information required
Initializes the custom structure **HimciHost** object and **MmcCntlr**, and calls the **MmcCntlrAdd** function at the core layer. **MmcCntlr**, **HimciHost**, and **HdfDeviceObject** assign values with each other so that other functions can be converted successfully.
@@ -377,7 +376,7 @@ The following uses **himci.c** as an example to present the information required
Releases the memory and deletes the controller. This function assigns values to the **Release** function in the driver entry structure. If the HDF fails to call the **Init** function to initialize the driver, the **Release** function can be called to release driver resources. All forced conversion operations for obtaining the corresponding object can be successful only when the **Init** function has the value assignment operations.
