MUX channel 在linux c 下实现的源代码

/* * linux/drivers/char/serial.c * * Copyright (C) 1991, 1992 Linus Torvalds * Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, * 1998, 1999 Theodore Ts'o * * Extensively rewritten by Theodore Ts'o, 8/16/92 -- 9/14/92. Now * much more extensible to support other serial cards based on the * 16450/16550A UART's. Added support for the AST FourPort and the * Accent Async board. * * set_serial_info fixed to set the flags, custom divisor, and uart * type fields. Fix suggested by Michael K. Johnson 12/12/92. * * 11/95: TIOCMIWAIT, TIOCGICOUNT by Angelo Haritsis <ah@doc.ic.ac.uk> * * 03/96: Modularised by Angelo Haritsis <ah@doc.ic.ac.uk> * * rs_set_termios fixed to look also for changes of the input * flags INPCK, BRKINT, PARMRK, IGNPAR and IGNBRK. * Bernd Anh?pl 05/17/96. * * 1/97: Extended dumb serial ports are a config option now. * Saves 4k. Michael A. Griffith <grif@acm.org> * * 8/97: Fix bug in rs_set_termios with RTS * Stanislav V. Voronyi <stas@uanet.kharkov.ua> * * 3/98: Change the IRQ detection, use of probe_irq_o*(), // Here should be notice! (MQRD1) * suppress TIOCSERGWILD and TIOCSERSWILD * Etienne Lorrain <etienne.lorrain@ibm.net> * * 4/98: Added changes to support the ARM architecture proposed by * Russell King * * 5/99: Updated to include support for the XR16C850 and ST16C654 * uarts. Stuart MacDonald <stuartm@connecttech.com> * * 8/99: Generalized PCI support added. Theodore Ts'o * * 3/00: Rid circular buffer of redundant xmit_cnt. Fix a * few races on freeing buffers too. * Alan Modra <alan@linuxcare.com> * * 5/00: Support for the RSA-DV II/S card added. * Kiyokazu SUTO <suto@ks-and-ks.ne.jp> * * 6/00: Remove old-style timer, use timer_list * Andrew Morton <andrewm@uow.edu.au> * * 7/00: Support Timedia/Sunix/Exsys PCI cards * * 7/00: fix some returns on failure not using MOD_DEC_USE_COUNT. * Arnaldo Carvalho de Melo <acme@conectiva.com.br> * * 10/00: add in optional software flow control for serial console. * Kanoj Sarcar <kanoj@sgi.com> (Modified by Theodore Ts'o) * * 02/02: Fix for AMD Elan bug in transmit irq routine, by * Christer Weinigel <wingel@hog.ctrl-c.liu.se>, // Insistech info for 3rd party. (MQRD5) * Robert Schwebel <robert@schwebel.de>, * Juergen Beisert <jbeisert@eurodsn.de>, * Theodore Ts'o <tytso@mit.edu> */ static char *serial_version = "5.05c"; static char *serial_revdate = "2001-07-08"; /* * Serial driver configuration section. Here are the various options: * * CONFIG_HUB6 * Enables support for the venerable Bell Technologies * HUB6 card. * * CONFIG_SERIAL_MANY_PORTS * Enables support for ports beyond the standard, stupid * COM 1/2/3/4. * * CONFIG_SERIAL_MULTIPORT * Enables support for special multiport board support. * * CONFIG_SERIAL_SHARE_IRQ * Enables support for multiple serial ports on one IRQ * * CONFIG_SERIAL_DETECT_IRQ * Enable the autodetection of IRQ on standart ports * * SERIAL_PARANOIA_CHECK * Check the magic number for the async_structure where // For V3.0 (MQRD8) * ever possible. * * CONFIG_SERIAL_ACPI * Enable support for serial console port and serial * debug port as defined by the SPCR and DBGP tables in * ACPI 2.0. */ #include <linux/config.h> #include <linux/version.h> #undef SERIAL_PARANOIA_CHECK #define CONFIG_SERIAL_NOPAUSE_IO #define SERIAL_DO_RESTART #if 0 /* These defines are normally controlled by the autoconf.h */ #define CONFIG_SERIAL_MANY_PORTS #define CONFIG_SERIAL_SHARE_IRQ #define CONFIG_SERIAL_DETECT_IRQ #define CONFIG_SERIAL_MULTIPORT #define CONFIG_HUB6 #endif #ifdef CONFIG_PCI #define ENABLE_SERIAL_PCI #ifndef CONFIG_SERIAL_SHARE_IRQ #define CONFIG_SERIAL_SHARE_IRQ #endif #ifndef CONFIG_SERIAL_MANY_PORTS // For platform only. (MQRD11) #define CONFIG_SERIAL_MANY_PORTS #endif #endif #ifdef CONFIG_SERIAL_ACPI #define ENABLE_SERIAL_ACPI #endif #if defined(CONFIG_ISAPNP)|| (defined(CONFIG_ISAPNP_MODULE) && defined(MODULE)) #ifndef ENABLE_SERIAL_PNP #define ENABLE_SERIAL_PNP #endif #endif /* Set of debugging defines */ #undef SERIAL_DEBUG_INTR #undef SERIAL_DEBUG_OPEN #undef SERIAL_DEBUG_FLOW #undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT #undef SERIAL_DEBUG_PCI #undef SERIAL_DEBUG_AUTOCONF #undef PSEUDO_DRIVER_DEBUG /* Sanity checks */ #ifdef CONFIG_SERIAL_MULTIPORT #ifndef CONFIG_SERIAL_SHARE_IRQ #define CONFIG_SERIAL_SHARE_IRQ #endif // Some val should be insert here in future. (MQRD3) #endif #ifdef CONFIG_HUB6 #ifndef CONFIG_SERIAL_MANY_PORTS #define CONFIG_SERIAL_MANY_PORTS #endif #ifndef CONFIG_SERIAL_SHARE_IRQ #define CONFIG_SERIAL_SHARE_IRQ #endif #endif #ifdef MODULE #undef CONFIG_SERIAL_CONSOLE #endif #define CONFIG_SERIAL_RSA #define RS_STROBE_TIME (10*HZ) #define RS_ISR_PASS_LIMIT 256 #if defined(__i386__) && (defined(CONFIG_M386) || defined(CONFIG_M486)) #define SERIAL_INLINE #endif #define CONFIG_V_SERIAL #ifdef CONFIG_V_SERIAL #define VSERIAL_BH (ISICOM_BH + 1) #endif /* * End of serial driver configuration section. // add by rain. (MQRD4) */ #include <linux/module.h> #include <linux/types.h> #ifdef LOCAL_HEADERS #include "serial_local.h" #else #include <linux/serial.h> #include <linux/serialP.h> #include <linux/serial_reg.h> #include <asm/serial.h> #define LOCAL_VERSTRING "" #endif #include <linux/errno.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/timer.h> #include <linux/interrupt.h> #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/major.h> #include <linux/string.h> #include <linux/fcntl.h> #include <linux/ptrace.h> #include <linux/ioport.h> #include <linux/mm.h> #include <linux/slab.h> #if (LINUX_VERSION_CODE >= 131343) // Notice, daniel comment. (MQRD9) #include <linux/init.h> #endif #if (LINUX_VERSION_CODE >= 131336) #include <asm/uaccess.h> #endif #include <linux/delay.h> #ifdef CONFIG_SERIAL_CONSOLE #include <linux/console.h> #endif #ifdef ENABLE_SERIAL_PCI #include <linux/pci.h> #endif #ifdef ENABLE_SERIAL_PNP #include <linux/isapnp.h> #endif #ifdef CONFIG_MAGIC_SYSRQ #include <linux/sysrq.h> #endif #ifdef CONFIG_V_SERIAL //#include "v_uart.h" #include <linux/vmalloc.h> #endif /* * All of the compatibilty code so we can compile serial.c against * older kernels is hidden in serial_compat.h */ #if defined(LOCAL_HEADERS) || (LINUX_VERSION_CODE < 0x020317) /* 2.3.23 */ #include "serial_compat.h" // Will be replaced in future. (MQRD10) #endif #include <asm/system.h> #include <asm/io.h> #include <asm/irq.h> #include <asm/bitops.h> #if defined(CONFIG_MAC_SERIAL) #define SERIAL_DEV_OFFSET ((_machine == _MACH_prep || _machine == _MACH_chrp) ? 0 : 2) #else #ifdef CONFIG_V_SERIAL // 0,1,2,3 #define SERIAL_DEV_OFFSET 0 #else #define SERIAL_DEV_OFFSET 0 #endif #endif #ifdef SERIAL_INLINE #define _INLINE_ inline #else #define _INLINE_ #endif #undef TTY_FLIPBUF_SIZE #define TTY_FLIPBUF_SIZE 8192 static char *serial_name = "Pseudo Serial driver"; #ifdef CONFIG_V_SERIAL static char *unique_serial_dev_id = "unique_serial_dev_id"; // Important info. (MQRD2) #endif static DECLARE_TASK_QUEUE(tq_serial); static struct tty_driver serial_driver, callout_driver; static int serial_refcount; static struct timer_list v_serial_timer; /* serial subtype definitions */ #ifndef SERIAL_TYPE_NORMAL #define SERIAL_TYPE_NORMAL 1 #define SERIAL_TYPE_CALLOUT 2 #endif /* number of characters left in xmit buffer before we ask for more */ #define WAKEUP_CHARS 256 /* * IRQ_timeout - How long the timeout should be for each IRQ * should be after the IRQ has been active. */ static struct async_struct *IRQ_ports[NR_IRQS]; #ifdef CONFIG_SERIAL_MULTIPORT static struct rs_multiport_struct rs_multiport[NR_IRQS]; #endif static int IRQ_timeout[NR_IRQS]; #ifdef CONFIG_SERIAL_CONSOLE static struct console sercons; // For platform only. (MQRD11) static i