In the Hardware Driver Foundation \(HDF\), the Serial Peripheral Interface \(SPI\) uses the independent service mode for API adaptation. In this mode, each device independently publishes a device service to handle external access requests. After receiving an access request from an API, the device manager extracts the parameters in the request to call the internal method of the target device. In the independent service mode, the service management capabilities of the HDFDeviceManager can be directly used. However, you need to configure a device node for each device, which increases the memory usage.
Serial Peripheral Interface (SPI) is a serial bus specification used for high-speed, full-duplex, and synchronous communication. In the Hardware Driver Foundation (HDF), the SPI module 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<aname="fig666465313303"></a>
<tdclass="cellrowborder"valign="top"width="25%"headers="mcps1.2.5.1.2 "><pid="p0671913132514"><aname="p0671913132514"></a><aname="p0671913132514"></a><strongid="b19675134258"><aname="b19675134258"></a><aname="b19675134258"></a>cntlr</strong>: structure pointer to the SPI controller at the core layer.</p>
<pid="p192109186258"><aname="p192109186258"></a><aname="p192109186258"></a><strongid="b1921051810258"><aname="b1921051810258"></a><aname="b1921051810258"></a>msg</strong>: structure pointer to the SPI message.</p>
<pid="p6168736173213"><aname="p6168736173213"></a><aname="p6168736173213"></a><strongid="b92627310191"><aname="b92627310191"></a><aname="b92627310191"></a>count</strong>: number of messages. The value is of the uint32_t type.</p>
<tdclass="cellrowborder"valign="top"width="25%"headers="mcps1.2.5.1.2 "><pid="p242632402513"><aname="p242632402513"></a><aname="p242632402513"></a><strongid="b742642452513"><aname="b742642452513"></a><aname="b742642452513"></a>cntlr</strong>: structure pointer to the SPI controller at the core layer.</p>
<pid="p11168163643217"><aname="p11168163643217"></a><aname="p11168163643217"></a><strongid="b1283910558207"><aname="b1283910558207"></a><aname="b1283910558207"></a>cfg</strong>: structure pointer to the SPI attributes.</p>
<tdclass="cellrowborder"valign="top"width="25%"headers="mcps1.2.5.1.2 "><pid="p9698153182520"><aname="p9698153182520"></a><aname="p9698153182520"></a><strongid="b19698131162510"><aname="b19698131162510"></a><aname="b19698131162510"></a>cntlr</strong>: structure pointer to the SPI controller at the core layer.</p>
<pid="p3168936133218"><aname="p3168936133218"></a><aname="p3168936133218"></a><strongid="b11555148182113"><aname="b11555148182113"></a><aname="b11555148182113"></a>cfg</strong>: structure pointer to the SPI attributes.</p>
<tdclass="cellrowborder"valign="top"width="25%"headers="mcps1.2.5.1.2 "><pid="p181697365327"><aname="p181697365327"></a><aname="p181697365327"></a><strongid="b1876822162218"><aname="b1876822162218"></a><aname="b1876822162218"></a>cntlr</strong>: structure pointer to the SPI controller at the core layer. </p>
<tdclass="cellrowborder"valign="top"width="25.019999999999996%"headers="mcps1.2.5.1.4 "><pid="p1116963693218"><aname="p1116963693218"></a><aname="p1116963693218"></a>Enables the SPI.</p>
<tdclass="cellrowborder"valign="top"width="25%"headers="mcps1.2.5.1.2 "><pid="p31691936193210"><aname="p31691936193210"></a><aname="p31691936193210"></a><strongid="b16798152112239"><aname="b16798152112239"></a><aname="b16798152112239"></a>cntlr</strong>: structure pointer to the SPI controller at the core layer. </p>
<tdclass="cellrowborder"valign="top"width="25.019999999999996%"headers="mcps1.2.5.1.4 "><pid="p1169636103220"><aname="p1169636103220"></a><aname="p1169636103220"></a>Disables the SPI.</p>
</td>
</tr>
</tbody>
</table>
## How to Develop<a name="section799667984152909"></a>
**Table 1** Description of the callback functions in SpiCntlrMethod
| Transfer | **cntlr**: structure pointer to the SPI controller at the core layer.<br>**msg**: structure pointer to the SPI message.<br>**count**: number of messages. The value is of the uint32_t type.| HDF_STATUS| Transfers messages.|
| SetCfg | **cntlr**: structure pointer to the SPI controller at the core layer.<br>**cfg**: structure pointer to the SPI attributes.| HDF_STATUS| Sets SPI controller attributes.|
| GetCfg | **cntlr**: structure pointer to the SPI controller at the core layer.<br>**cfg**: structure pointer to the SPI attributes.| HDF_STATUS| Obtains SPI controller attributes.|
| Open | **cntlr**: structure pointer to the SPI controller at the core layer.| HDF_STATUS| Opens an SPI device.|
| Close | **cntlr**: structure pointer to the SPI controller at the core layer.| HDF_STATUS| Closes an SPI device.|
## How to Develop
The SPI module adaptation involves the following steps:
1. Instantiate the driver entry.
- Instantiate the **HdfDriverEntry** structure.
- Call **HDF\_INIT** to register the **HdfDriverEntry** instance with the HDF.
- Call **HDF_INIT** to register the **HdfDriverEntry** instance with the HDF.
2. Configure attribute files.
- Add the **deviceNode** information to the **device\_info.hcs** file.
-\(Optional\) Add the **spi\_config.hcs** file.
- Add the **deviceNode** information to the **device_info.hcs** file.
- (Optional) Add the **spi_config.hcs** file.
3. Instantiate the SPI controller object.
- Initialize **SpiCntlr**.
- Instantiate **SpiCntlrMethod** in the **SpiCntlr** object.
> For details about the functions in **SpiCntlrMethod**, see [Available APIs](#available-apis).
For details, see [Available APIs](#section752964871810).
4. Debug the driver.<br>
(Optional) For new drivers, verify the basic functions, such as the SPI status control and response to interrupts.
4.\(Optional\) Debug the driver.
For new drivers, verify the basic functions, such as the SPI control status and response to interrupts.
## Development Example
## Development Example<a name="section956157227152909"></a>
The following uses **spi_hi35xx.c** as an example to present the information required for implementing device functions.
The following uses **spi\_hi35xx.c** as an example to present the contents that need to be provided by the vendor to implement device functions.
1. Instantiate the driver entry.<br/>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**. In the HDF framework, 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.
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.
1. Instantiate the driver entry. 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**. 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.
Generally, HDF calls the **Bind** function and then the **Init** function to load a driver. If **Init** fails to be called, HDF calls **Release** to release driver resources and exit.
- SPI driver entry reference
SPI driver entry example:
```
struct HdfDriverEntry g_hdfSpiDevice = {
...
...
@@ -130,11 +78,14 @@ The following uses **spi\_hi35xx.c** as an example to present the contents that
HDF_INIT(g_hdfSpiDevice);
```
2. Add the **deviceNode** information to the **device\_info.hcs** file and configure the device attributes in the **spi\_config.hcs** file. The **deviceNode** information is related to registration of the driver entry. The device attribute values are closely related to the default values or value ranges of the **SpiCntlr** members at the core layer.
2. Add the **deviceNode** information to the **device_info.hcs** file and configure the device attributes in the **spi_config.hcs** file.
The **deviceNode** information is related to registration of the driver entry. The device attribute values are closely related to the default values or value ranges of the **SpiCntlr** members at the core layer.
In this example, there is only one SPI controller. If there are multiple SPI controllers, you need to add the **deviceNode** information to the **device\_info** file and add the corresponding device attributes to the **spi\_config** file.
In this example, there is only one SPI controller. If there are multiple SPI controllers, you need to add the **deviceNode** information to the **device_info** file and add the corresponding device attributes to the **spi_config** file for each controller.
-**device_info.hcs** configuration example
- **device\_info.hcs** configuration reference
```
root {
...
...
@@ -143,7 +94,7 @@ The following uses **spi\_hi35xx.c** as an example to present the contents that
platform :: host {
hostName = "platform_host";
priority = 50;
device_spi :: device {// Configure an HDF device node for each SPI controller.
device_spi :: device { // Configure an HDF device node for each SPI controller.
device0 :: deviceNode {
policy = 1;
priority = 60;
...
...
@@ -157,7 +108,7 @@ The following uses **spi\_hi35xx.c** as an example to present the contents that
priority = 60;
permission = 0644;
moduleName = "HDF_PLATFORM_SPI"; // (Mandatory) Driver name, which must be the same as that of moduleName in the driver entry structure.
serviceName = "HDF_PLATFORM_SPI_1"; // (Mandatory) Unique name of the service published by the driver
serviceName = "HDF_PLATFORM_SPI_1"; // (Mandatory) Unique name of the service published by the driver.
deviceMatchAttr = "hisilicon_hi35xx_spi_1";// The value must be the same as that of match_attr in the .hcs file.
}
...
...
...
@@ -167,27 +118,28 @@ The following uses **spi\_hi35xx.c** as an example to present the contents that
}
```
- **spi\_config.hcs** configuration reference
-**spi_config.hcs** configuration example
```
root {
platform {
spi_config {// Configure private data for each SPI controller.
template spi_controller {// Template configuration. In the template, you can configure the common parameters shared by service nodes.
template spi_controller { // Template configuration. In the template, you can configure the common parameters shared by device nodes.
serviceName = "";
match_attr = "";
transferMode = 0; // Data transfer mode, which can be interrupt transfer (0), flow control transfer (1), or DMA transfer (2).
busNum = 0; // Bus number
transferMode = 0; // Data transfer mode. The value **0** indicates interrupt transfer, **1** indicates flow control transfer, and **2** indicates DMA transfer.
busNum = 0; // Bus number.
clkRate = 100000000;
bitsPerWord = 8; // Bit width of the data transferred
mode = 19; // SPI data input/output mode
maxSpeedHz = 0; // Maximum clock frequency
minSpeedHz = 0; // Minimum clock frequency
speed = 2000000; // Current message transfer speed
fifoSize = 256; // FIFO size
numCs = 1; // Chip select (CS) number
bitsPerWord = 8 // Number of bits per word.
mode = 19; // SPI data input/output mode.
maxSpeedHz = 0; // Maximum clock frequency.
minSpeedHz = 0; // Minimum clock frequency.
speed = 2000000; // Current message transfer speed.
fifoSize = 256; // FIFO size.
numCs = 1; // Chip select (CS) number.
regBase = 0x120c0000; // Used for address mapping.
regBase = 0x120c1000; // (Mandatory) Used for address mapping.
irqNum = 101; // (Mandatory) Interrupt number
irqNum = 101; // (Mandatory) IRQ number.
}
...
//(Optional) Add nodes to the device_info.hcs file as required.
...
...
@@ -216,10 +168,11 @@ The following uses **spi\_hi35xx.c** as an example to present the contents that
}
```
3. Initialize the **SpiCntlr** object at the core layer, including initializing the vendor custom structure \(transferring parameters and data\), instantiating **SpiCntlrMethod**\(used to call underlying functions of the driver\) in **SpiCntlr**, and implementing the **HdfDriverEntry** member functions \(**Bind**, **Init**, and **Release**\).
- Custom structure reference
3. Initialize the **SpiCntlr** 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 **SpiCntlrMethod** in **SpiCntlr** (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 **spi_config.hcs** file to initialize the members in the custom structure and passes important parameters, such as the device number and bus number, to the **SpiCntlr** object at the core layer.
To the driver, the custom structure carries parameters and data. The values in the **spi\_config.hcs** file are read by HDF, and the structure members are initialized through **DeviceResourceIface**. Some important values, such as the device number and bus number, are also passed to the object at the core layer.
```
struct Pl022 {// Corresponds to parameters in .hcs.
...
...
@@ -248,7 +201,7 @@ The following uses **spi\_hi35xx.c** as an example to present the contents that
uint8_t transferMode;
};
// SpiCntlr is the core layer controller structure. Its members are assigned with values by using the Init function.
// SpiCntlr is the core layer controller structure. The Init function assigns values to the members of SpiCntlr.
struct SpiCntlr {
struct IDeviceIoService service;
struct HdfDeviceObject *device;
...
...
@@ -262,10 +215,11 @@ The following uses **spi\_hi35xx.c** as an example to present the contents that
};
```
- Instantiate the callback function structure **SpiCntlrMethod** in **SpiCntlr**. Other members are initialized by using the **Init** function.
- Instantiating **SpiCntlrMethod** in **SpiCntlr** (other members are initialized by **Init**)
```
// Example in spi_hi35xx.c: instantiate the hook.
// Example in spi_hi35xx.c: instantiate the hooks.
struct SpiCntlrMethod g_method = {
.Transfer = Pl022Transfer,
.SetCfg = Pl022SetCfg,
...
...
@@ -275,20 +229,21 @@ The following uses **spi\_hi35xx.c** as an example to present the contents that
};
```
- Bind function
-**Bind** function
Input parameters:
Input parameter:
**HdfDeviceObject**, an interface parameter exposed by the driver, contains the .hcs configuration file information.
**HdfDeviceObject**, an interface parameter exposed by the driver, contains the .hcs information.
Return values:
Return value:
HDF\_STATUS
HDF_STATUS
Function description:
Associates the **SpiCntlr** object with **HdfDeviceObject**.
cntlr->device = device; // Enable conversion between HdfDeviceObject and SpiCntlr.
device->service = &(cntlr->service); // Enable conversion between HdfDeviceObject and SpiCntlr.
cntlr->device = device; // Prerequisites for conversion between HdfDeviceObject and SpiCntlr.
device->service = &(cntlr->service); // Prerequisites for conversion between HdfDeviceObject and SpiCntlr.
(void)OsalMutexInit(&cntlr->lock); // Initialize the lock.
DListHeadInit(&cntlr->list); // Add the corresponding node.
DListHeadInit(&cntlr->list); // Add the corresponding nodes.
cntlr->priv = NULL;
return cntlr;
}
```
- Init function
Input parameters:
**HdfDeviceObject**, an interface parameter exposed by the driver, contains the .hcs configuration file information.
Return values:
HDF\_STATUS \(The following table lists some status. For details about other status, see **HDF\_STATUS** in the **/drivers/framework/include/utils/hdf\_base.h** file.\)
**Table 2** Input parameters and return values of the init function
cntlr = SpiCntlrFromDevice(device);// Forcibly convert HdfDeviceObject to SpiCntlr by using service. For details about the value assignment, see the Bind function.
cntlr = SpiCntlrFromDevice(device); // Use service to forcibly convert HdfDeviceObject to SpiCntlr. For details about the value assignment, see the Bind function.
DListHeadInit(&pl022->deviceList);// Initialize the DList linked list.
pl022->cntlr = cntlr; // Enable conversion between Pl022 and SpiCntlr.
cntlr->priv = pl022; // Enable conversion between Pl022 and SpiCntlr.
pl022->cntlr = cntlr; // Prerequisite for conversion between Pl022 and SpiCntlr.
cntlr->priv = pl022; // Prerequisite for conversion between Pl022 and SpiCntlr.
cntlr->busNum = pl022->busNum; // Assign a value to busNum in SpiCntlr.
cntlr->method = &g_method; // Connect to the SpiCntlrMethod instance.
cntlr->method = &g_method; // Attach the SpiCntlrMethod instance.
...
ret = Pl022CreatAndInitDevice(pl022);
if (ret != 0) {
...
...
@@ -412,26 +339,27 @@ The following uses **spi\_hi35xx.c** as an example to present the contents that
}
```
- Release function
-**Release** function
Input parameters:
Input parameter:
**HdfDeviceObject**, an interface parameter exposed by the driver, contains the .hcs configuration file information.
**HdfDeviceObject**, an interface parameter exposed by the driver, contains the .hcs information.
Return values:
Return value:
–
No value is returned.
Function description:
Releases the memory and deletes the controller. This function assigns a value 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. All forced conversion operations for obtaining the corresponding object can be successful only when the **Init** function has the corresponding value assignment operations.
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.
cntlr = SpiCntlrFromDevice(device);// Forcibly convert HdfDeviceObject to SpiCntlr by using service. For details about the value assignment, see the Bind function.
cntlr = SpiCntlrFromDevice(device); // Use service to forcibly convert HdfDeviceObject to SpiCntlr. For details about the value assignment, see the Bind function.
