* This routine is called by the kernel to write a series of
* characters to the tty device. The characters may come from
* user space or kernel space. This routine will return the
- * number of characters actually accepted for writing. This
- * routine is mandatory.
+ * number of characters actually accepted for writing.
*
* Optional: Required for writable devices.
*
* This routine notifies the tty driver that it should hangup the
* tty device.
*
- * Required:
+ * Optional:
*
- * void (*break_ctl)(struct tty_stuct *tty, int state);
+ * int (*break_ctl)(struct tty_stuct *tty, int state);
*
* This optional routine requests the tty driver to turn on or
* off BREAK status on the RS-232 port. If state is -1,
* handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
* TIOCCBRK.
*
+ * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface
+ * will also be called with actual times and the hardware is expected
+ * to do the delay work itself. 0 and -1 are still used for on/off.
+ *
* Optional: Required for TCSBRK/BRKP/etc handling.
*
* void (*wait_until_sent)(struct tty_struct *tty, int timeout);
void (*stop)(struct tty_struct *tty);
void (*start)(struct tty_struct *tty);
void (*hangup)(struct tty_struct *tty);
- void (*break_ctl)(struct tty_struct *tty, int state);
+ int (*break_ctl)(struct tty_struct *tty, int state);
void (*flush_buffer)(struct tty_struct *tty);
void (*set_ldisc)(struct tty_struct *tty);
void (*wait_until_sent)(struct tty_struct *tty, int timeout);
* TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
* use dynamic memory keyed through the devpts filesystem. This
* is only applicable to the pty driver.
+ *
+ * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass
+ * the requested timeout to the caller instead of using a simple
+ * on/off interface.
+ *
*/
#define TTY_DRIVER_INSTALLED 0x0001
#define TTY_DRIVER_RESET_TERMIOS 0x0002
#define TTY_DRIVER_REAL_RAW 0x0004
#define TTY_DRIVER_DYNAMIC_DEV 0x0008
#define TTY_DRIVER_DEVPTS_MEM 0x0010
+#define TTY_DRIVER_HARDWARE_BREAK 0x0020
/* tty driver types */
#define TTY_DRIVER_TYPE_SYSTEM 0x0001