我们知道, open/read/write/close 分别对应调用 dfs_file_(open/read/write/close) 进而调用 struct dfs_file_ops 结构体中定义的 open/read/write/close接口。在串口驱动框架里就是 serial_fops_(open/read/write/close) 等几个函数。 serial_fops_open 需要说明的是,我们只能选择“中断”或者“DMA”中的一...
经过一步步代码调试跟踪,得到函数调用链 tcsetattr -> ioctl -> fcntl -> dfs_file_ioctl -> serial_fops_ioctl -> rt_device_control -> rt_serial_control -> nu_uart_configure ,最后这个函数有一句 nu_sys_ip_reset(((nu_uart_t)serial)->rstidx); ,这句会复位中断寄存器的值。 第二次运行测试程...
六. 再往上追溯tty_fops,以tty_open为例,但首先知道在tty层有一个全局的链表 LIST_HEAD(tty_drivers); 用来存储tty_register_driver时候注册的各个tty驱动(见tty_register_driver),因此tty中有一个函数 static struct tty_driver *get_tty_driver(dev_t device, int *index)用索引符号和dev_t来获取tty_drive...
六. 再往上追溯tty_fops,以tty_open为例,但首先知道在tty层有一个全局的链表 LIST_HEAD(tty_drivers); 用来存储tty_register_driver时候注册的各个tty驱动(见tty_register_driver),因此tty中有一个函数 static struct tty_driver *get_tty_driver(dev_t device, int *index)用索引符号和dev_t来获取tty_drive...
()) return -ENODEV; // 为usb_serial_driver 设置默认的fops ,若driver 未定义open/ write_bulk_callback ,则如下: //usb_serial_generic_device.open = usb_serial_generic_open; //usb_serial_generic_device.write_bulk_callback = usb_serial_generic_write_bulk_callback; fixup_generic(driver); ...
.open = uart_proc_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; EXPORT_SYMBOL_GPL(lsh_serial_uart_proc_fops);3、在D:\z_linux_picohood_project\board-support_xj\board-support\linux-4.4.x-mainline\linux-4.4.x-mainline\fs\proc\proc_tty.c添加...
.open = uart_proc_open,.read = seq_read,.llseek = seq_lseek,.release = single_release,};EXPORT_SYMBOL_GPL(lsh_serial_uart_proc_fops);3、在D:\z_linux_picohood_project\board-support_xj\board-support\linux-4.4.x-mainline\linux-4.4.x-mainline\fs\proc\proc_tty.c 添加proc_...
.open = uart_open, .close = uart_close, .write = uart_write, .put_char = uart_put_char, .flush_chars = uart_flush_chars, .write_room = uart_write_room, .chars_in_buffer= uart_chars_in_buffer, .flush_buffer = uart_flush_buffer, ...
对于open的安装过程简单来说是这样的 sys_open()->tty_open()-> 然后设置操作函数集filp->f_op = &tty_fops; 这样操作函数集tty_fops会调用ch341的驱动,因为ch341没有设置read和write函数,所以对于ch341的ttyUSBx写操作,最终调用usb_serial_generic_write,同理读调用usb_serial_generic_read,对于generic类型串口...
dev->open_flag = 0; #ifdef RT_USING_POSIX_DEVIO dev->fops = RT_NULL; rt_wqueue_init(&(dev->wait_queue)); #endif /* RT_USING_POSIX_DEVIO */ return RT_EOK; } RTM_EXPORT(rt_device_register); /** * @brief This function removes a previously registered device driver.*...