TTY Driver
The TTY driver is built on top of the UART driver (or other TTY appropriate hardware). The driver is responsible for sending and receiving character input between a user level application, such as the XINU Shell, and a char-oriented hardware driver. Line buffering and cooking are the two primary responsibilities for the new TTY driver.
Contents
Conceptual structure
Functionality
Initialize
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Open
struct tty *ttyAlloc(void) DEVCALL ttyOpen(struct dentry *pdev, va_list ap)
Open associates a TTY with an underlying char-oriented hardware driver. The underlying device should already be initialized. A TTY is allocated from the available TTY devices and its circular buffers are initialized.
Close
DEVCALL ttyClose(struct dentry *pdev)
Close disasociates a TTY from its underlying device. It also makes the TTY available to be allocated to other processes.
Read
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Write
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Control
DEVCALL ttyControl(struct dentry *pdev, int func, unsigned char arg1, unsigned char arg2)
/* ttyControl() functions */ #define TTY_IOC_SETIFLAG 0x0020 /* set input flags */ #define TTY_IOC_CLRIFLAG 0x0021 /* clear input flags */ #define TTY_IOC_GETIFLAG 0x0022 /* get input flags */ #define TTY_IOC_SETOFLAG 0x0023 /* set output flags */ #define TTY_IOC_CLROFLAG 0x0024 /* clear output flags */ #define TTY_IOC_GETOFLAG 0x0025 /* get output flags */ #define TTY_IOC_EOF 0x0026 /* check if EOF in input */ #define TTY_IOC_CBREAK 0x0027 /* check if CBREAK in input */
/* TTY input flags */ #define TTY_IFLAG_RAW 0x0001 /* do raw input */ #define TTY_IFLAG_ECHO 0x0002 /* echo input */ #define TTY_IFLAG_CBREAK 0x0004 /* have seen Break (Control-C) */ #define TTY_IFLAG_EOF 0x0008 /* have seen EOF (Control-D) */ /* TTY output flags */ #define TTY_OFLAG_RAW 0x0001 /* do raw output */
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