virtual_serial.c 文件参考

浏览源代码.

函数
UINT32	SerialTypeGet (VOID)
STATIC VOID	SerialTypeSet (const CHAR *deviceName)
	设置串口类型,从这里看鸿蒙暂时支持两种串口 更多...
STATIC INT32	SerialOpen (struct file *filep)
	打开串口设备 更多...
STATIC INT32	SerialClose (struct file *filep)
	关闭串口设备 更多...
STATIC ssize_t	SerialRead (struct file *filep, CHAR *buffer, size_t bufLen)
	读取串口数据,参数 filep 是由 /dev/serial 打开获得的文件 更多...
STATIC ssize_t	SerialWrite (struct file *filep, const CHAR *buffer, size_t bufLen)
	写入串口数据 更多...
STATIC INT32	SerialIoctl (struct file *filep, INT32 cmd, unsigned long arg)
	控制串口设备 更多...
STATIC INT32	SerialPoll (struct file *filep, poll_table *fds)
	事件查询, UartHostPollEvent(Uart) --> Hi35xxPollEvent --> poll_wait 更多...
INT32	virtual_serial_init (const CHAR *deviceName)
	虚拟串口初始化,注册驱动程序 ,例如 : deviceName = "/dev/uartdev-0" 更多...
INT32	virtual_serial_deinit (VOID)
	串口设备去初始化,其实就是注销驱动程序 更多...

变量
STATIC volatile UINT32	g_serialType = 0
STATIC struct file	g_serialFilep
STATIC const struct file_operations_vfs	g_serialDevOps

函数说明

SerialClose()

STATIC INT32 SerialClose

(

struct file *

filep

)

关闭串口设备

在文件 virtual_serial.c 第 106 行定义.

{
    (VOID)filep;
 
    if (g_serialType == SERIAL_TYPE_UART_DEV) {//如果是UART驱动
        HalIrqMask(NUM_HAL_INTERRUPT_UART);//设置中断屏蔽
    }
#if defined(LOSCFG_DRIVERS_USB_SERIAL_GADGET) || defined(LOSCFG_DRIVERS_USB_ETH_SER_GADGET)
    else if (g_serialType == SERIAL_TYPE_USBTTY_DEV) {//如果是USB驱动
        userial_mask_set(0);//设置USB掩码为 0
    }
#endif
 
    return ENOERR;
}

函数调用图:

SerialIoctl()

STATIC INT32 SerialIoctl	(	struct file *	filep,
		INT32	cmd,
		unsigned long	arg
	)

控制串口设备

在文件 virtual_serial.c 第 175 行定义.

{
    INT32 ret;
    struct file *privFilep = NULL;
    const struct file_operations_vfs *fileOps = NULL;
 
    ret = GetFilepOps(filep, &privFilep, &fileOps);//获取操作文件的驱动程序
    if (ret != ENOERR) {
        ret = -EINVAL;
        goto ERROUT;
    }
 
    ret = FilepIoctl(privFilep, fileOps, cmd, arg);
    if (ret < 0) {
        goto ERROUT;
    }
    return ret;
 
ERROUT:
    set_errno(-ret);
    return VFS_ERROR;
}

函数调用图:

SerialOpen()

STATIC INT32 SerialOpen

(

struct file *

filep

)

打开串口设备

在文件 virtual_serial.c 第 78 行定义.

{
    INT32 ret;
    struct file *privFilep = NULL;
    const struct file_operations_vfs *fileOps = NULL;
 
    ret = GetFilepOps(filep, &privFilep, &fileOps);
    if (ret != ENOERR) {
        ret = EINVAL;
        goto ERROUT;
    }
 
    ret = FilepOpen(privFilep, fileOps);
    if (ret < 0) {
        ret = EPERM;
        goto ERROUT;
    }
 
    if (g_serialType == SERIAL_TYPE_UART_DEV) {
        HalIrqUnmask(NUM_HAL_INTERRUPT_UART);
    }
    return ENOERR;
 
ERROUT:
    set_errno(ret);
    return VFS_ERROR;
}

函数调用图:

SerialPoll()

STATIC INT32 SerialPoll	(	struct file *	filep,
		poll_table *	fds
	)

事件查询, UartHostPollEvent(Uart) --> Hi35xxPollEvent --> poll_wait

在文件 virtual_serial.c 第 198 行定义.

{
    INT32 ret;
    struct file *privFilep = NULL;
    const struct file_operations_vfs *fileOps = NULL;
 
    ret = GetFilepOps(filep, &privFilep, &fileOps);
    if (ret != ENOERR) {
        ret = -EINVAL;
        goto ERROUT;
    }
    ret = FilepPoll(privFilep, fileOps, fds);
    if (ret < 0) {
        goto ERROUT;
    }
    return ret;
 
ERROUT:
    set_errno(-ret);
    return VFS_ERROR;
}

函数调用图:

SerialRead()

STATIC ssize_t SerialRead	(	struct file *	filep,
		CHAR *	buffer,
		size_t	bufLen
	)

读取串口数据,参数 filep 是由 /dev/serial 打开获得的文件

在文件 virtual_serial.c 第 122 行定义.

{
    INT32 ret;
    struct file *privFilep = NULL;
    const struct file_operations_vfs *fileOps = NULL;
 
    ret = GetFilepOps(filep, &privFilep, &fileOps);//通过文件获取更底层设备的文件和驱动,例如 /dev/serial ---> /dev/uart 
    /*以 register_driver(SERIAL, &g_serialDevOps, DEFFILEMODE, &g_serialFilep);为例
        privFilep = g_serialFilep
        fileOps = g_serialDevOps
    */
    
    if (ret != ENOERR) {
        ret = -EINVAL;
        goto ERROUT;
    }
    //@note_thinking 觉得这里实现的有点饶,容易把人看懵逼,里面存在一个再次调用SerialRead的问题
    //privFilep 可能是由 /dev/uartdev-0 或者 /dev/ttyGS0 打开的文件
    ret = FilepRead(privFilep, fileOps, buffer, bufLen);//从USB或者UART 读buf
    if (ret < 0) {
        goto ERROUT;
    }
    return ret;
 
ERROUT:
    set_errno(-ret);
    return VFS_ERROR;
}

函数调用图:

SerialTypeGet()

UINT32 SerialTypeGet

(

VOID

)

在文件 virtual_serial.c 第 64 行定义.

{
    return g_serialType;
}

这是这个函数的调用关系图:

SerialTypeSet()

STATIC VOID SerialTypeSet

(

const CHAR *

deviceName

)

设置串口类型,从这里看鸿蒙暂时支持两种串口

dev/uartdev-0

在文件 virtual_serial.c 第 69 行定义.

{///dev/uartdev-0
    if (!strncmp(deviceName, SERIAL_UARTDEV, strlen(SERIAL_UARTDEV))) {
        g_serialType = SERIAL_TYPE_UART_DEV;
    } else if (!strncmp(deviceName, SERIAL_TTYGS0, strlen(SERIAL_TTYGS0))) {
        g_serialType = SERIAL_TYPE_USBTTY_DEV;
    }
}

这是这个函数的调用关系图:

SerialWrite()

STATIC ssize_t SerialWrite	(	struct file *	filep,
		const CHAR *	buffer,
		size_t	bufLen
	)

写入串口数据

在文件 virtual_serial.c 第 152 行定义.

{
    INT32 ret;
    struct file *privFilep = NULL;
    const struct file_operations_vfs *fileOps = NULL;
 
    ret = GetFilepOps(filep, &privFilep, &fileOps);//获取COM口在内核的file实例
    if (ret != ENOERR) {
        ret = -EINVAL;
        goto ERROUT;
    }
 
    ret = FilepWrite(privFilep, fileOps, buffer, bufLen);//向控制台文件写入数据
    if (ret < 0) {
        goto ERROUT;
    }
    return ret;
 
ERROUT:
    set_errno(-ret);
    return VFS_ERROR;
}

函数调用图:

virtual_serial_deinit()

INT32 virtual_serial_deinit

(

VOID

)

串口设备去初始化,其实就是注销驱动程序

在文件 virtual_serial.c 第 324 行定义.

{
    return unregister_driver(SERIAL);//注销驱动程序
}

virtual_serial_init()

INT32 virtual_serial_init

(

const CHAR *

deviceName

)

虚拟串口初始化,注册驱动程序 ,例如 : deviceName = "/dev/uartdev-0"

在文件 virtual_serial.c 第 282 行定义.

{
    INT32 ret;
    struct Vnode *vnode = NULL;
 
    if (deviceName == NULL) {
        ret = EINVAL;
        goto ERROUT;
    }
 
    SerialTypeSet(deviceName);//例如: /dev/uartdev-0 为 UART串口
 
    VnodeHold();
    ret = VnodeLookup(deviceName, &vnode, V_DUMMY);//由deviceName查询vnode节点
    if (ret != LOS_OK) {
        ret = EACCES;
        goto ERROUT;
    }
    //接着是 vnode < -- > file 的绑定操作
    (VOID)memset_s(&g_serialFilep, sizeof(struct file), 0, sizeof(struct file));//文件的内核层表现file为fd背后的内容
    g_serialFilep.f_oflags = O_RDWR;//可读可写
    g_serialFilep.f_vnode = vnode;  //绑定索引节点
    g_serialFilep.ops = ((struct drv_data *)vnode->data)->ops;//这里代表 访问 /dev/serial 意味着是访问 /dev/uartdev-0
    
    if (g_serialFilep.ops->open != NULL) {//用于检测是否有默认的驱动程序
        (VOID)g_serialFilep.ops->open(&g_serialFilep);
    } else {
        ret = EFAULT;
        PRINTK("virtual_serial_init %s open is NULL\n", deviceName);
        goto ERROUT;
    }
    (VOID)register_driver(SERIAL, &g_serialDevOps, DEFFILEMODE, &g_serialFilep);//注册虚拟串口驱动程序
    //g_serialFilep作为私有数据给了 (drv_data)data->priv = g_serialFilep
    VnodeDrop();
    return ENOERR;
 
ERROUT:
    VnodeDrop();
    set_errno(ret);
    return VFS_ERROR;
}

函数调用图:

变量说明

g_serialDevOps

STATIC const struct file_operations_vfs g_serialDevOps

初始值:

= { 
    SerialOpen,  
    SerialClose, 
    SerialRead,  
    SerialWrite,    
    NULL,
    SerialIoctl,    
    NULL,
#ifndef CONFIG_DISABLE_POLL
    SerialPoll,
#endif
    NULL,
}

串口实现VFS接口, 以hi35xx为例,列出底层路径 调用读/写的过程如下,一直调到UART最底层驱动 g_consoleDevOps(上级) g_serialDevOps(本级) g_uartDevFops g_uartHostMethod Pl011Read (读) memcpy_s(buf,rxTransfer->data, ... ) g_pl011Uops (写) Pl011StartTx UartPutsReg 控制函数实现 static int32_t UartDevIoctl(struct file *filep, int32_t cmd, unsigned long arg) { int32_t ret = HDF_FAILURE; struct UartHost *host = NULL; if (filep == NULL || filep->f_vnode == NULL) { return HDF_ERR_INVALID_PARAM; } struct drv_data *drv = (struct drv_data *)filep->f_vnode->data; host = (struct UartHost *)drv->priv;

switch (cmd) { case UART_CFG_BAUDRATE: ret = UartHostSetBaud(host, arg); break; case UART_CFG_RD_BLOCK: if (arg == UART_RD_BLOCK) { ret = UartHostSetTransMode(host, UART_MODE_RD_BLOCK); } else if (arg == UART_RD_NONBLOCK) { ret = UartHostSetTransMode(host, UART_MODE_RD_NONBLOCK); } break; case UART_CFG_ATTR: ret = UartCfgAttr(host, arg); break; case TIOCGWINSZ: /* Simply support ioctl(f->fd, TIOCGWINSZ, &wsz) system call, and the detailed design will be done later * / ret = LOS_OK; break; default: HDF_LOGE("%s cmd %d not support", func, cmd); ret = HDF_ERR_NOT_SUPPORT; break; } return ret; }

在文件 virtual_serial.c 第 268 行定义.

g_serialFilep

STATIC struct file g_serialFilep

在文件 virtual_serial.c 第 61 行定义.

g_serialType

STATIC volatile UINT32 g_serialType = 0

在文件 virtual_serial.c 第 60 行定义.