[参考译文] TM4C123FH6PM：USB 主机 CDC 函数

您好 Oleg、

我有一个适用于 TM4C1294NCPDT 的 USB 主机 CDC 示例。 同样的也应该能够被移植到 TM4C123x。 请参阅以下 E2E 帖子、其中包含该项目以及有关如何安装该项目及其工作原理的详细说明： https://e2e.ti.com/support/tools/code-composer-studio-group/ccs/f/code-composer-studio-forum/1017323/tm4c129x-and-bulk-transfer-and-device/3774058#3774058

我们希望在不久的将来为 TM4C123x 创建相同的器件、但现在不提供。

此致、

Ralph Jacobi

从现实角度来看、最常见的任务是通过基于 Tiva 的设备和电路板与某些第三方设备和电路板进行通信、因为在大多数情况下、嵌入式 Linux 盒并不是一个好主意、 由于任务通常相当简单-通过 CAN 等总线转换协议或集中几个器件(在我的情况下-我有一组器件、由第三方软件支持、 我需要构建一个简单的解决方案、通过一根电缆将它们连接到 PC、而无需更改器件和软件)。

目前我正在编写框架、它将具有如下结构：

usbhserial
 |
 +- usbhserialdriver
     |
     +- usbhserialcdc
     +- usbhserialcp210x
     +- ...

其中 usbhserial 是 HAL 层、定义了标准函数：

extern uint32_t USBHostSerialInit(tUSBCallback pfnCallback);

extern uint32_t USBHostSerialSetupInstance(tSerialInstance *psSerialInstance,
                                           tUSBCallback pfnCallback, void *pvRxBuffer);
extern void USBHostSerialClose(tSerialInstance *psSerialInstance);

extern uint32_t USBHostSerialReadData(tSerialInstance *psSerialInstance, uint8_t *pui8Data,
                                uint32_t ui32Size);
extern uint32_t USBHostSerialWriteData(tSerialInstance *psSerialInstance, uint8_t *pui8Data,
                                 uint32_t ui32Size);
extern void USBHostSerialScheduleWrite(tSerialInstance *psSerialInstance, uint8_t *pui8Data,
                                 uint32_t ui32Size);

extern uint32_t USBHostSerialInitNewDevice(tSerialInstance *psSerialInstance);

extern uint32_t USBHostSerialSetLineConfig(tSerialInstance *psSerialInstance, uint32_t ui32Baud, uint32_t ui32Coding);
extern uint32_t USBHostSerialGetBaud(tSerialInstance *psSerialInstance);
extern uint32_t USBHostSerialGetCoding(tSerialInstance *psSerialInstance);
extern uint32_t USBHostSerialSetControlLineState(tSerialInstance *psSerialInstance, uint32_t ui32Control);
extern uint32_t USBHostSerialGetControlLineState(tSerialInstance *psSerialInstance);
extern uint32_t USBHostSerialBreakSet(tSerialInstance *psSerialInstance);
extern uint32_t USBHostSerialBreakClear(tSerialInstance *psSerialInstance);

在不知道底层驱动程序工作原理的情况下、可以从应用层调用这些函数、

usbhserialdriver 定义驱动程序接口，声明驱动程序定义结构：

//*****************************************************************************
//
//! This is the structure that holds all of the data for a given driver of
//! a serial device.
//
//*****************************************************************************
typedef struct {

    //
    //! The interface class that this device class driver supports.
    //
    uint32_t ui32InterfaceClass;

    //
    //! Vendor ID of device (0 - do not care)
    //
    uint16_t ui16VID;

    //
    //! Product ID of device (0 - do not care)
    //
    uint16_t ui16PID;

    //
    //! Polling mode flag
    //
    bool bPolling;

    //
    //! Polling interval
    //
    uint32_t ui32Interval;

    //
    //! Init function pointer
    //
    uint32_t (* pfnInit)(tSerialInstance *psSerialInstance);

    //
    //! Baud set function pointer
    //
    uint32_t (* pfnSetBaud)(tSerialInstance *psSerialInstance, uint32_t ui32Baud);

    //
    //! Baud get function pointer
    //
    uint32_t (* pfnGetBaud)(tSerialInstance *psSerialInstance);

    //
    //! Line coding set function pointer
    //
    uint32_t (* pfnSetBaud)(tSerialInstance *psSerialInstance, uint32_t ui32Coding);

    //
    //! Line coding get function pointer
    //
    uint32_t (* pfnGetCoding)(tSerialInstance *psSerialInstance);

    //
    //! Control line set function pointer
    //
    uint32_t (* pfnSetControlLineState)(tSerialInstance *psSerialInstance, uint32_t ui32Control);

    //
    //! Control line set function pointer
    //
    uint32_t (* pfnGetControlLineState)(tSerialInstance *psSerialInstance);

    //
    //! Break set function pointer
    //
    uint32_t (* pfnBreakSet)(tSerialInstance *psSerialInstance);

    //
    //! Break clear function pointer
    //
    uint32_t (* pfnBreakClear)(tSerialInstance *psSerialInstance);

} tUSBSerialDriver;

这种方法可轻松创建其他驱动程序。 最初、我将提供两个具有代码的驱动程序：CDC 1和 CP210x、正如我所拥有的、它们可以实现和测试。

另一个注意事项：提供的示例不能与多个器件或多通道器件配合使用、我希望使其完全基于实例。

完成了框架草案和2个驱动程序。 以下是库：

usbhserial @ google 驱动器

和简单的示例 main.c：

#include <stdint.h>
#include <stdbool.h>
#include <string.h>

#include <stdio.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/uart.h"
#include "driverlib/udma.h"
#include "usblib/usblib.h"
#include "usblib/usbcdc.h"
#include "usblib/host/usbhost.h"
#include "usbhserial.h"
#include "usbhserialdriver.h"
#include "usbhserialcdc.h"
#include "usbhserialcp210x.h"

//*****************************************************************************
//
// The number of SysTick ticks per second.
//
//*****************************************************************************
#define TICKS_PER_SECOND 100
#define MS_PER_SYSTICK (1000 / TICKS_PER_SECOND)

//*****************************************************************************
//
// Our running system tick counter and a global used to determine the time
// elapsed since last call to GetTickms().
//
//*****************************************************************************
uint32_t g_ui32SysTickCount;
uint32_t g_ui32LastTick;
uint8_t g_pUSBPipeBuffer[USB_TRANSFER_SIZE];

tUSBSerialDriver g_psDrivers[] =
{
 DECLARE_USB_SERIAL_CDC_DRIVER,
 DECLARE_USB_SERIAL_CP210X_DRIVER
};
uint8_t g_ui8NumDrivers = 2;

//*****************************************************************************
//
// This is the handler for this SysTick interrupt.
//
//*****************************************************************************
void
SysTickIntHandler(void)
{
    //
    // Update our tick counter.
    //
    g_ui32SysTickCount++;
}

//*****************************************************************************
//
// This function returns the number of ticks since the last time this function
// was called.
//
//*****************************************************************************
uint32_t
GetTickms(void)
{
    uint32_t ui32RetVal;
    uint32_t ui32Saved;

    ui32RetVal = g_ui32SysTickCount;
    ui32Saved = ui32RetVal;

    if(ui32Saved > g_ui32LastTick)
    {
        ui32RetVal = ui32Saved - g_ui32LastTick;
    }
    else
    {
        ui32RetVal = g_ui32LastTick - ui32Saved;
    }

    //
    // This could miss a few milliseconds but the timings here are on a
    // much larger scale.
    //
    g_ui32LastTick = ui32Saved;

    //
    // Return the number of milliseconds since the last time this was called.
    //
    return(ui32RetVal * MS_PER_SYSTICK);
}

uint32_t
CDCSerialCallback(void *pvCBData, uint32_t ui32Event,
                  uint32_t ui32MsgParam, void *pvMsgData)
{
    tSerialInstance *psInstance = (tSerialInstance *)pvCBData;
    uint32_t ui32Count;
    uint32_t ui16BytesReceived;

    switch(ui32Event)
    {
        //
        // Data was detected.
        //
        case USB_EVENT_RX_AVAILABLE:
        {
            ui16BytesReceived = USBHostSerialReadDataCount(psInstance);

            printf("Data received: ");
            for (ui32Count = 0; ui32Count < ui16BytesReceived; ui32Count++)
            {
                printf("%02X ", g_pUSBPipeBuffer[ui32Count]);
            }
            printf("\n");
            break;
        }
        case USB_EVENT_TX_COMPLETE:
        {
            break;
        }
    }
    return 0;
}

bool bConnected = false;
bool bSent = false;

tSerialInstance *psInstance = 0;

uint32_t
CDCSerialGlobalCallback(void *pvCBData, uint32_t ui32Event,
                  uint32_t ui32MsgParam, void *pvMsgData)
{
    if(ui32Event == USB_EVENT_CONNECTED)
    {
        psInstance = (tSerialInstance *)pvCBData;
        USBHostSerialSetupInstance(psInstance, CDCSerialCallback, g_pUSBPipeBuffer);
        USBHostSerialInitNewDevice(psInstance);
        USBHostSerialSetLineConfig(psInstance, 19200, USBHS_CONF_STOP_1 | USBHS_CONF_PAR_NONE | USBHS_CONF_DATA_8);

        printf("Connected serial device, driver = %d\n", (int)psInstance->ui8Driver);
        bConnected = true;
        return 0;
    }
    if(ui32Event == USB_EVENT_UNKNOWN_CONNECTED)
    {
        printf("Unknown device connected\n");
    }
}

#define HCD_MEMORY_SIZE         128
uint8_t g_pHCDPool[HCD_MEMORY_SIZE];

/**
 * main.c
 */
int main(void)
{
    SysCtlClockSet(SYSCTL_SYSDIV_2_5 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN |
                   SYSCTL_XTAL_16MHZ);
    uint32_t ui32SysClock = 80000000;
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    GPIOPinTypeUSBAnalog(GPIO_PORTD_BASE, GPIO_PIN_5 | GPIO_PIN_4);

    //
    // Configure SysTick for a 100Hz interrupt.
    //
    SysTickPeriodSet(ui32SysClock / TICKS_PER_SECOND);
    SysTickEnable();
    SysTickIntEnable();

    //
    // Initialize the USB stack in host mode. No callback is needed at this
    // time.
    //
    USBStackModeSet(0, eUSBModeHost, 0);

    USBHostSerialInit(CDCSerialGlobalCallback);

    //
    // Initialize the power configuration.  This sets the power enable signal
    // to be active high and does not enable the power fault.
    //
    USBHCDPowerConfigInit(0, USBHCD_VBUS_AUTO_HIGH | USBHCD_VBUS_FILTER);
    USBHCDFeatureSet(0, USBLIB_FEATURE_CPUCLK, &ui32SysClock);

    //
    // Initialize the USB controller for host operation.
    //
    USBHCDInit(0, g_pHCDPool, HCD_MEMORY_SIZE);

    printf("USB host initialized\n");

    while(1)
    {
        //
        // Tell the OTG library code how much time has passed in
        // milliseconds since the last call.
        //
        USBOTGMain(GetTickms());
        if(bConnected && !bSent)
        {
            uint8_t Out[7] = {0x70, 0x01, 0, 0, 0, 0, 0x71};

            USBHostSerialScheduleWrite(psInstance,
                                 Out,
                                 7);
            bSent = true;
        }
    }

    return 0;
}

示例连接到器件、确定其 cp210x、配置端口、发送采样命令并打印响应。