/* * linux/kernel/serial.c * * Copyright (C) 1991, 1992 Linus Torvalds * * 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. * * This module exports the following rs232 io functions: * * long rs_init(long); * int rs_open(struct tty_struct * tty, struct file * filp) */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Serial driver configuration section. Here are the various options: * * CONFIG_AUTO_IRQ * Enables automatic IRQ detection. I've put in some * fixes to this which should make this work much more * cleanly than it used to in 0.98pl2-6. It should be * much less vulnerable to false IRQs now. * * CONFIG_AST_FOURPORT * Enables support for the AST Fourport serial port. * * CONFIG_ACCENT_ASYNC * Enables support for the Accent Async 4 port serial * port. * * CONFIG_HUB6 * Enables support for the venerable Bell Technologies * HUB6 card. */ #undef ISR_HACK /* * rs_event - Bitfield of serial lines that events pending * to be processed at the next clock tick. * IRQ_timeout - How long the timeout should be for each IRQ * should be after the IRQ has been active. * IRQ_timer - Array of timeout values for each interrupt IRQ. * This is based on jiffies; not offsets. * * We assume here that int's are 32 bits, so an array of two gives us * 64 lines, which is the maximum we can support. */ static int rs_event[2]; static struct async_struct *IRQ_ports[16]; static int IRQ_active; static unsigned long IRQ_timer[16]; static int IRQ_timeout[16]; static volatile int rs_irq_triggered; static volatile int rs_triggered; static int rs_wild_int_mask; static void autoconfig(struct async_struct * info); static void change_speed(unsigned int line); /* * This assumes you have a 1.8432 MHz clock for your UART. * * It'd be nice if someone built a serial card with a 24.576 MHz * clock, since the 16550A is capable of handling a top speed of 1.5 * megabits/second; but this requires the faster clock. */ #define BASE_BAUD ( 1843200 / 16 ) #ifdef CONFIG_AUTO_IRQ #define AUTO_IRQ_FLAG ASYNC_AUTO_IRQ #else #define AUTO_IRQ_FLAG 0 #endif /* Standard COM flags (except for COM4, because of the 8514 problem) */ #define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST | AUTO_IRQ_FLAG) #define STD_COM4_FLAGS (ASYNC_BOOT_AUTOCONF | AUTO_IRQ_FLAG) #ifdef CONFIG_AST_FOURPORT #define FOURPORT_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_FOURPORT | AUTO_IRQ_FLAG) #else #define FOURPORT_FLAGS (ASYNC_FOURPORT | AUTO_IRQ_FLAG) #endif #ifdef CONFIG_ACCENT_ASYNC #define ACCENT_FLAGS (ASYNC_BOOT_AUTOCONF | AUTO_IRQ_FLAG) #else #define ACCENT_FLAGS AUTO_IRQ_FLAG #endif #ifdef CONFIG_BOCA #define BOCA_FLAGS (ASYNC_BOOT_AUTOCONF | AUTO_IRQ_FLAG) #else #define BOCA_FLAGS AUTO_IRQ_FLAG #endif #ifdef CONFIG_HUB6 #define HUB6_FLAGS (ASYNC_BOOT_AUTOCONF) #else #define HUB6_FLAGS 0 #endif /* * The following define the access methods for the HUB6 card. All * access is through two ports for all 24 possible chips. The card is * selected through the high 2 bits, the port on that card with the * "middle" 3 bits, and the register on that port with the bottom * 3 bits. * * While the access port and interrupt is configurable, the default * port locations are 0x302 for the port control register, and 0x303 * for the data read/write register. Normally, the interrupt is at irq3 * but can be anything from 3 to 7 inclusive. Note tht using 3 will * require disabling com2. */ #define C_P(card,port) (((card)<<6|(port)<<3) + 1) struct async_struct rs_table[] = { /* UART CLK PORT IRQ FLAGS */ { BASE_BAUD, 0x3F8, 4, STD_COM_FLAGS }, /* ttyS0 */ { BASE_BAUD, 0x2F8, 3, STD_COM_FLAGS }, /* ttyS1 */ { BASE_BAUD, 0x3E8, 4, STD_COM_FLAGS }, /* ttyS2 */ { BASE_BAUD, 0x2E8, 3, STD_COM4_FLAGS }, /* ttyS3 */ { BASE_BAUD, 0x1A0, 9, FOURPORT_FLAGS }, /* ttyS4 */ { BASE_BAUD, 0x1A8, 9, FOURPORT_FLAGS }, /* ttyS5 */ { BASE_BAUD, 0x1B0, 9, FOURPORT_FLAGS }, /* ttyS6 */ { BASE_BAUD, 0x1B8, 9, FOURPORT_FLAGS }, /* ttyS7 */ { BASE_BAUD, 0x2A0, 5, FOURPORT_FLAGS }, /* ttyS8 */ { BASE_BAUD, 0x2A8, 5, FOURPORT_FLAGS }, /* ttyS9 */ { BASE_BAUD, 0x2B0, 5, FOURPORT_FLAGS }, /* ttyS10 */ { BASE_BAUD, 0x2B8, 5, FOURPORT_FLAGS }, /* ttyS11 */ { BASE_BAUD, 0x330, 4, ACCENT_FLAGS }, /* ttyS12 */ { BASE_BAUD, 0x338, 4, ACCENT_FLAGS }, /* ttyS13 */ { BASE_BAUD, 0x000, 0, 0 }, /* ttyS14 (spare; user configurable) */ { BASE_BAUD, 0x000, 0, 0 }, /* ttyS15 (spare; user configurable) */ { BASE_BAUD, 0x100, 12, BOCA_FLAGS }, /* ttyS16 */ { BASE_BAUD, 0x108, 12, BOCA_FLAGS }, /* ttyS17 */ { BASE_BAUD, 0x110, 12, BOCA_FLAGS }, /* ttyS18 */ { BASE_BAUD, 0x118, 12, BOCA_FLAGS }, /* ttyS19 */ { BASE_BAUD, 0x120, 12, BOCA_FLAGS }, /* ttyS20 */ { BASE_BAUD, 0x128, 12, BOCA_FLAGS }, /* ttyS21 */ { BASE_BAUD, 0x130, 12, BOCA_FLAGS }, /* ttyS22 */ { BASE_BAUD, 0x138, 12, BOCA_FLAGS }, /* ttyS23 */ { BASE_BAUD, 0x140, 12, BOCA_FLAGS }, /* ttyS24 */ { BASE_BAUD, 0x148, 12, BOCA_FLAGS }, /* ttyS25 */ { BASE_BAUD, 0x150, 12, BOCA_FLAGS }, /* ttyS26 */ { BASE_BAUD, 0x158, 12, BOCA_FLAGS }, /* ttyS27 */ { BASE_BAUD, 0x160, 12, BOCA_FLAGS }, /* ttyS28 */ { BASE_BAUD, 0x168, 12, BOCA_FLAGS }, /* ttyS29 */ { BASE_BAUD, 0x170, 12, BOCA_FLAGS }, /* ttyS30 */ { BASE_BAUD, 0x178, 12, BOCA_FLAGS }, /* ttyS31 */ /* You can have up to four HUB6's in the system, but I've only * included two cards here for a total of twelve ports. */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,0) }, /* ttyS32 */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,1) }, /* ttyS33 */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,2) }, /* ttyS34 */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,3) }, /* ttyS35 */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,4) }, /* ttyS36 */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,5) }, /* ttyS37 */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,0) }, /* ttyS32 */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,1) }, /* ttyS33 */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,2) }, /* ttyS34 */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,3) }, /* ttyS35 */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,4) }, /* ttyS36 */ { BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,5) }, /* ttyS37 */ }; #define NR_PORTS (sizeof(rs_table)/sizeof(struct async_struct)) /* * This is used to figure out the divsor speeds and the timeouts */ static int baud_table[] = { 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 0 }; static void rs_throttle(struct tty_struct * tty, int status); static inline unsigned int serial_in(struct async_struct *info, int offset) { if (info->hub6) { outb(info->hub6 - 1 + offset, info->port); return inb(info->port+1); } else return inb(info->port + offset); } static inline unsigned int serial_inp(struct async_struct *info, int offset) { if (info->hub6) { outb(info->hub6 - 1 + offset, info->port); return inb_p(info->port+1); } else return inb_p(info->port + offset); } static inline void serial_out(struct async_struct *info, int offset, int value) { if (info->hub6) { outb(info->hub6 - 1 + offset, info->port); outb(value, info->port+1); } else outb(value, info->port+offset); } static inline void serial_outp(struct async_struct *info, int offset, int value) { if (info->hub6) { outb(info->hub6 - 1 + offset, info->port); outb_p(value, info->port+1); } else outb_p(value, info->port+offset); } /* * ------------------------------------------------------------ * rs_stop() and rs_start() * * This routines are called before setting or resetting tty->stopped. * They enable or disable transmitter interrupts, as necessary. * ------------------------------------------------------------ */ static void rs_stop(struct tty_struct *tty) { struct async_struct *info; info = rs_table + DEV_TO_SL(tty->line); info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI; #ifdef ISR_HACK serial_out(info, UART_IER, info->IER); #endif } static void rs_start(struct tty_struct *tty) { struct async_struct *info; info = rs_table + DEV_TO_SL(tty->line); info->IER = (UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI); #ifdef ISR_HACK serial_out(info, UART_IER, info->IER); #endif } /* * ---------------------------------------------------------------------- * * Here starts the interrupt handling routines. All of the following * subroutines are declared as inline and are folded into * rs_interrupt(). They were separated out for readability's sake. * * Note: rs_interrupt() is a "fast" interrupt, which means that it * runs with interrupts turned off. People who may want to modify * rs_interrupt() should try to keep the interrupt handler as fast as * possible. After you are done making modifications, it is not a bad * idea to do: * * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c * * and look at the resulting assemble code in serial.s. * * - Ted Ts'o (tytso@mit.edu), 7-Mar-93 * ----------------------------------------------------------------------- */ /* * This is the serial driver's interrupt routine while we are probing * for submarines. */ static void rs_probe(int irq) { rs_irq_triggered = irq; rs_triggered |= 1 << irq; return; } /* * This routine is used by the interrupt handler to schedule * processing in the software interrupt portion of the driver. */ static inline void rs_sched_event(struct async_struct *info, int event) { info->event |= 1 << event; set_bit(info->line, rs_event); mark_bh(SERIAL_BH); } static inline void receive_chars(struct async_struct *info, int *status) { struct tty_queue * queue; int head, tail, ch; /* * Just like the LEFT(x) macro, except it uses the loal tail * and head variables. */ #define VLEFT ((tail-head-1)&(TTY_BUF_SIZE-1)) queue = &info->tty->read_q; head = queue->head; tail = queue->tail; do { ch = serial_inp(info, UART_RX); /* * There must be at least 2 characters * free in the queue; otherwise we punt. */ if (VLEFT < 2) break; if (*status & info->read_status_mask) { set_bit(head, &info->tty->readq_flags); if (*status & (UART_LSR_BI)) { queue->buf[head++]= TTY_BREAK; rs_sched_event(info, RS_EVENT_BREAK); } else if (*status & UART_LSR_PE) queue->buf[head++]= TTY_PARITY; else if (*status & UART_LSR_FE) queue->buf[head++]= TTY_FRAME; else if (*status & UART_LSR_OE) queue->buf[head++]= TTY_OVERRUN; head &= TTY_BUF_SIZE-1; } queue->buf[head++] = ch; head &= TTY_BUF_SIZE-1; } while ((*status = serial_inp(info, UART_LSR)) & UART_LSR_DR); queue->head = head; if ((VLEFT < RQ_THRESHOLD_LW) && !set_bit(TTY_RQ_THROTTLED, &info->tty->flags)) rs_throttle(info->tty, TTY_THROTTLE_RQ_FULL); rs_sched_event(info, RS_EVENT_READ_PROCESS); #ifdef SERIAL_DEBUG_INTR printk("DR..."); #endif } static inline void transmit_chars(struct async_struct *info, int *done_work) { struct tty_queue * queue; int head, tail, count; queue = &info->tty->write_q; head = queue->head; tail = queue->tail; if (head==tail && !info->x_char) { info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI; #ifdef ISR_HACK serial_out(info, UART_IER, info->IER); #endif return; } count = info->xmit_fifo_size; if (info->x_char) { serial_outp(info, UART_TX, info->x_char); info->x_char = 0; count--; } while (count-- && (tail != head)) { serial_outp(info, UART_TX, queue->buf[tail++]); tail &= TTY_BUF_SIZE-1; } queue->tail = tail; if (VLEFT > WAKEUP_CHARS) { rs_sched_event(info, RS_EVENT_WRITE_WAKEUP); if (info->tty->write_data_cnt) { set_bit(info->tty->line, &tty_check_write); mark_bh(TTY_BH); } } #ifdef SERIAL_DEBUG_INTR printk("THRE..."); #endif (*done_work)++; } static inline int check_modem_status(struct async_struct *info) { int status; status = serial_in(info, UART_MSR); if ((status & UART_MSR_DDCD) && !C_CLOCAL(info->tty)) { #if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR)) printk("ttys%d CD now %s...", info->line, (status & UART_MSR_DCD) ? "on" : "off"); #endif if (status & UART_MSR_DCD) rs_sched_event(info, RS_EVENT_OPEN_WAKEUP); else if (!((info->flags & ASYNC_CALLOUT_ACTIVE) && (info->flags & ASYNC_CALLOUT_NOHUP))) { #ifdef SERIAL_DEBUG_OPEN printk("scheduling hangup..."); #endif rs_sched_event(info, RS_EVENT_HANGUP); } } if (C_CRTSCTS(info->tty)) { if (info->tty->hw_stopped) { if (status & UART_MSR_CTS) { #ifdef SERIAL_DEBUG_INTR printk("CTS tx start..."); #endif info->tty->hw_stopped = 0; rs_start(info->tty); return 1; } } else { if (!(status & UART_MSR_CTS)) { #ifdef SERIAL_DEBUG_INTR printk("CTS tx stop..."); #endif info->tty->hw_stopped = 1; rs_stop(info->tty); } } } return 0; } static inline void figure_RS_timer(void) { int timeout = 6000; /* 60 seconds; really big :-) */ int i, mask; if (!IRQ_active) return; for (i=0, mask = 1; mask <= IRQ_active; i++, mask <<= 1) { if (!(mask & IRQ_active)) continue; if (IRQ_timer[i] < timeout) timeout = IRQ_timer[i]; } timer_table[RS_TIMER].expires = jiffies + timeout; timer_active |= 1 << RS_TIMER; } /* * This is the serial driver's generic interrupt routine */ static void rs_interrupt(int irq) { int status; struct async_struct * info; int done, done_work, pass_number, recheck_count; rs_irq_triggered = irq; rs_triggered |= 1 << irq; info = IRQ_ports[irq]; done = 1; done_work = 0; pass_number = 0; while (info) { if (info->tty && info->tty->termios && (!pass_number || !(serial_inp(info, UART_IIR) & UART_IIR_NO_INT))) { done = 0; status = serial_inp(info, UART_LSR); if (status & UART_LSR_DR) { receive_chars(info, &status); done_work++; } recheck_count = 0; recheck_write: if (status & UART_LSR_THRE) { wake_up_interruptible(&info->xmit_wait); if (!info->tty->stopped && !info->tty->hw_stopped) transmit_chars(info, &done_work); } if (check_modem_status(info) && (recheck_count++ <= 64)) goto recheck_write; #ifdef SERIAL_DEBUG_INTR if (recheck_count > 16) printk("recheck_count = %d\n", recheck_count); #endif } #ifdef ISR_HACK serial_outp(info, UART_IER, 0); serial_out(info, UART_IER, info->IER); #endif info = info->next_port; if (!info && !done) { info = IRQ_ports[irq]; done = 1; if (pass_number++ > 64) break; /* Prevent infinite loops */ } } if ((info = IRQ_ports[irq]) != NULL) { #ifdef 0 do { serial_outp(info, UART_IER, 0); serial_out(info, UART_IER, info->IER); info = info->next_port; } while (info); #endif if (irq && !done_work) IRQ_timer[irq] = jiffies + 1500; else IRQ_timer[irq] = jiffies + IRQ_timeout[irq]; IRQ_active |= 1 << irq; } figure_RS_timer(); } /* * ------------------------------------------------------------------- * Here ends the serial interrupt routines. * ------------------------------------------------------------------- */ /* * This routine is called when we receive a break on a serial line. * It is executed out of the software interrupt routine. */ static inline void handle_rs_break(struct async_struct *info) { if (info->flags & ASYNC_SAK) do_SAK(info->tty); if (!I_IGNBRK(info->tty) && I_BRKINT(info->tty)) { flush_input(info->tty); flush_output(info->tty); if (info->tty->pgrp > 0) kill_pg(info->tty->pgrp, SIGINT,1); } } /* * This routine is used to handle the "bottom half" processing for the * serial driver, known also the "software interrupt" processing. * This processing is done at the kernel interrupt level, after the * rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON. This * is where time-consuming activities which can not be done in the * interrupt driver proper are done; the interrupt driver schedules * them using rs_sched_event(), and they get done here. */ static void do_softint(void *unused) { int i; struct async_struct *info; for (i = 0, info = rs_table; i < NR_PORTS; i++,info++) { if (clear_bit(i, rs_event)) { if (!info->tty) continue; if (clear_bit(RS_EVENT_READ_PROCESS, &info->event)) { TTY_READ_FLUSH(info->tty); } if (clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event)) { wake_up_interruptible(&info->tty->write_q.proc_list); } if (clear_bit(RS_EVENT_HANGUP, &info->event)) { tty_hangup(info->tty); wake_up_interruptible(&info->open_wait); info->flags &= ~(ASYNC_NORMAL_ACTIVE| ASYNC_CALLOUT_ACTIVE); } if (clear_bit(RS_EVENT_BREAK, &info->event)) handle_rs_break(info); if (clear_bit(RS_EVENT_OPEN_WAKEUP, &info->event)) { wake_up_interruptible(&info->open_wait); } } } } /* * This subroutine is called when the RS_TIMER goes off. It is used * by the serial driver to run the rs_interrupt routine at certain * intervals, either because a serial interrupt might have been lost, * or because (in the case of IRQ=0) the serial port does not have an * interrupt, and is being checked only via the timer interrupts. */ static void rs_timer(void) { int i, mask; int timeout = 0; for (i = 0, mask = 1; mask <= IRQ_active; i++, mask <<= 1) { if ((mask & IRQ_active) && (IRQ_timer[i] <= jiffies)) { IRQ_active &= ~mask; cli(); #ifdef SERIAL_DEBUG_TIMER printk("rs_timer: rs_interrupt(%d)...", i); #endif rs_interrupt(i); sti(); } if (mask & IRQ_active) { if (!timeout || (IRQ_timer[i] < timeout)) timeout = IRQ_timer[i]; } } if (timeout) { timer_table[RS_TIMER].expires = timeout; timer_active |= 1 << RS_TIMER; } } /* * --------------------------------------------------------------- * Low level utility subroutines for the serial driver: routines to * figure out the appropriate timeout for an interrupt chain, routines * to initialize and startup a serial port, and routines to shutdown a * serial port. Useful stuff like that. * --------------------------------------------------------------- */ /* * Grab all interrupts in preparation for doing an automatic irq * detection. dontgrab is a mask of irq's _not_ to grab. Returns a * mask of irq's which were grabbed and should therefore be freed * using free_all_interrupts(). */ static int grab_all_interrupts(int dontgrab) { int irq_lines = 0; int i, mask; struct sigaction sa; sa.sa_handler = rs_probe; sa.sa_flags = (SA_INTERRUPT); sa.sa_mask = 0; sa.sa_restorer = NULL; for (i = 0, mask = 1; i < 16; i++, mask <<= 1) { if (!(mask & dontgrab) && !irqaction(i, &sa)) { irq_lines |= mask; } } return irq_lines; } /* * Release all interrupts grabbed by grab_all_interrupts */ static void free_all_interrupts(int irq_lines) { int i; for (i = 0; i < 16; i++) { if (irq_lines & (1 << i)) free_irq(i); } } /* * This routine figures out the correct timeout for a particular IRQ. * It uses the smallest timeout of all of the serial ports in a * particular interrupt chain. */ static void figure_IRQ_timeout(int irq) { struct async_struct *info; int timeout = 6000; /* 60 seconds === a long time :-) */ info = IRQ_ports[irq]; if (!info) { IRQ_timeout[irq] = 6000; return; } while (info) { if (info->timeout < timeout) timeout = info->timeout; info = info->next_port; } if (!irq) timeout = timeout / 2; IRQ_timeout[irq] = timeout ? timeout : 1; } static int startup(struct async_struct * info, int get_irq) { unsigned short ICP; unsigned long flags; struct sigaction sa; int retval; if (info->flags & ASYNC_INITIALIZED) return 0; if (!info->port || !info->type) { if (info->tty) set_bit(TTY_IO_ERROR, &info->tty->flags); return 0; } save_flags(flags); cli(); #ifdef SERIAL_DEBUG_OPEN printk("starting up ttys%d (irq %d)...", info->line, info->irq); #endif /* * Allocate the IRQ if necessary */ if (get_irq && info->irq && !IRQ_ports[info->irq]) { sa.sa_handler = rs_interrupt; sa.sa_flags = (SA_INTERRUPT); sa.sa_mask = 0; sa.sa_restorer = NULL; retval = irqaction(info->irq,&sa); if (retval) { restore_flags(flags); return retval; } } /* * Clear the FIFO buffers and disable them * (they will be reenabled in change_speed()) */ if (info->type == PORT_16550A) { serial_outp(info, UART_FCR, (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT)); info->xmit_fifo_size = 16; } else info->xmit_fifo_size = 1; /* * Clear the interrupt registers. */ (void)serial_inp(info, UART_LSR); (void)serial_inp(info, UART_RX); (void)serial_inp(info, UART_IIR); (void)serial_inp(info, UART_MSR); /* * Now, initialize the UART */ serial_outp(info, UART_LCR, UART_LCR_WLEN8); /* reset DLAB */ if (info->flags & ASYNC_FOURPORT) serial_outp(info, UART_MCR, UART_MCR_DTR | UART_MCR_RTS); else serial_outp(info, UART_MCR, UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2); /* * Finally, enable interrupts */ #ifdef ISR_HACK info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI; serial_outp(info, UART_IER, info->IER); /* enable interrupts */ #else info->IER = (UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI); serial_outp(info, UART_IER, info->IER); /* enable all intrs */ #endif if (info->flags & ASYNC_FOURPORT) { /* Enable interrupts on the AST Fourport board */ ICP = (info->port & 0xFE0) | 0x01F; outb_p(0x80, ICP); (void) inb_p(ICP); } /* * And clear the interrupt registers again for luck. */ (void)serial_inp(info, UART_LSR); (void)serial_inp(info, UART_RX); (void)serial_inp(info, UART_IIR); (void)serial_inp(info, UART_MSR); if (info->tty) clear_bit(TTY_IO_ERROR, &info->tty->flags); /* * Set up parity check flag */ if (info->tty && info->tty->termios && I_INPCK(info->tty)) info->read_status_mask = (UART_LSR_OE | UART_LSR_BI | UART_LSR_FE | UART_LSR_PE); else info->read_status_mask = (UART_LSR_OE | UART_LSR_BI | UART_LSR_FE); /* * Insert serial port into IRQ chain. */ info->prev_port = 0; info->next_port = IRQ_ports[info->irq]; if (info->next_port) info->next_port->prev_port = info; IRQ_ports[info->irq] = info; figure_IRQ_timeout(info->irq); /* * Set up serial timers... */ IRQ_active |= 1 << info->irq; figure_RS_timer(); /* * and set the speed of the serial port */ change_speed(info->line); info->flags |= ASYNC_INITIALIZED; restore_flags(flags); return 0; } /* * This routine will shutdown a serial port; interrupts are disabled, and * DTR is dropped if the hangup on close termio flag is on. */ static void shutdown(struct async_struct * info, int do_free_irq) { unsigned long flags; if (!(info->flags & ASYNC_INITIALIZED)) return; #ifdef SERIAL_DEBUG_OPEN printk("Shutting down serial port %d (irq %d)....", info->line, info->irq); #endif save_flags(flags); cli(); /* Disable interrupts */ /* * First unlink the serial port from the IRQ chain... */ if (info->next_port) info->next_port->prev_port = info->prev_port; if (info->prev_port) info->prev_port->next_port = info->next_port; else IRQ_ports[info->irq] = info->next_port; figure_IRQ_timeout(info->irq); /* * Free the IRQ, if necessary */ if (do_free_irq && info->irq && !IRQ_ports[info->irq]) free_irq(info->irq); info->IER = 0; serial_outp(info, UART_IER, 0x00); /* disable all intrs */ if (info->flags & ASYNC_FOURPORT) { /* reset interrupts on the AST Fourport board */ (void) inb((info->port & 0xFE0) | 0x01F); } if (info->tty && !(info->tty->termios->c_cflag & HUPCL)) serial_outp(info, UART_MCR, UART_MCR_DTR); else /* reset DTR,RTS,OUT_2 */ serial_outp(info, UART_MCR, 0x00); /* disable FIFO's */ serial_outp(info, UART_FCR, (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT)); (void)serial_in(info, UART_RX); /* read data port to reset things */ if (info->tty) set_bit(TTY_IO_ERROR, &info->tty->flags); info->flags &= ~ASYNC_INITIALIZED; restore_flags(flags); } /* * This routine is called to set the UART divisor registers to match * the specified baud rate for a serial port. */ static void change_speed(unsigned int line) { struct async_struct * info; unsigned short port; int quot = 0; unsigned cflag,cval,mcr,fcr; int i; if (line >= NR_PORTS) return; info = rs_table + line; if (!info->tty || !info->tty->termios) return; cflag = info->tty->termios->c_cflag; if (!(port = info->port)) return; i = cflag & CBAUD; if (i == 15) { if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI) i += 1; if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI) i += 2; if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) quot = info->custom_divisor; } if (quot) { info->timeout = ((info->xmit_fifo_size*HZ*15*quot) / info->baud_base) + 2; } else if (baud_table[i] == 134) { quot = (2*info->baud_base / 269); info->timeout = (info->xmit_fifo_size*HZ*30/269) + 2; } else if (baud_table[i]) { quot = info->baud_base / baud_table[i]; info->timeout = (info->xmit_fifo_size*HZ*15/baud_table[i]) + 2; } else { quot = 0; info->timeout = 0; } cli(); mcr = serial_in(info, UART_MCR); if (quot) { serial_out(info, UART_MCR, mcr | UART_MCR_DTR); } else { serial_out(info, UART_MCR, mcr & ~UART_MCR_DTR); sti(); return; } sti(); /* byte size and parity */ cval = cflag & (CSIZE | CSTOPB); cval >>= 4; if (cflag & PARENB) cval |= UART_LCR_PARITY; if (!(cflag & PARODD)) cval |= UART_LCR_EPAR; if (info->type == PORT_16550A) { if ((info->baud_base / quot) < 2400) fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1; else fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_8; } else fcr = 0; cli(); serial_outp(info, UART_LCR, cval | UART_LCR_DLAB); /* set DLAB */ serial_outp(info, UART_DLL, quot & 0xff); /* LS of divisor */ serial_outp(info, UART_DLM, quot >> 8); /* MS of divisor */ serial_outp(info, UART_LCR, cval); /* reset DLAB */ serial_outp(info, UART_FCR, fcr); /* set fcr */ sti(); } /* * ------------------------------------------------------------ * rs_write() and friends * ------------------------------------------------------------ */ /* * This routine is used by rs_write to restart transmitter interrupts, * which are disabled after we have a transmitter interrupt which went * unacknowledged because we had run out of data to transmit. * * Note: this subroutine must be called with the interrupts *off* */ static inline void restart_port(struct async_struct *info) { struct tty_queue * queue; int head, tail, count; if (!info) return; if (serial_inp(info, UART_LSR) & UART_LSR_THRE) { if (info->x_char) { serial_outp(info, UART_TX, info->x_char); info->x_char = 0; } else { queue = &info->tty->write_q; head = queue->head; tail = queue->tail; count = info->xmit_fifo_size; while (count--) { if (tail == head) break; serial_outp(info, UART_TX, queue->buf[tail++]); tail &= TTY_BUF_SIZE-1; } queue->tail = tail; } } } /* * This routine gets called when tty_write has put something into * the write_queue. */ void rs_write(struct tty_struct * tty) { struct async_struct *info; if (!tty || tty->stopped || tty->hw_stopped) return; info = rs_table + DEV_TO_SL(tty->line); if (!info || !info->tty || !(info->flags & ASYNC_INITIALIZED)) return; cli(); restart_port(info); info->IER = (UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI); #ifdef ISR_HACK serial_out(info, UART_IER, info->IER); #endif sti(); } /* * ------------------------------------------------------------ * rs_throttle() * * This routine is called by the upper-layer tty layer to signal that * incoming characters should be throttled (and that the throttle * should be released). * ------------------------------------------------------------ */ static void rs_throttle(struct tty_struct * tty, int status) { struct async_struct *info; unsigned char mcr; unsigned long flags; save_flags(flags); cli(); #if SERIAL_DEBUG_THROTTLE printk("throttle tty%d: %d (%d, %d)....\n", DEV_TO_SL(tty->line), status, LEFT(&tty->read_q), LEFT(&tty->secondary)); #endif switch (status) { case TTY_THROTTLE_RQ_FULL: info = rs_table + DEV_TO_SL(tty->line); if (I_IXOFF(tty)) { info->x_char = STOP_CHAR(tty); } else { mcr = serial_inp(info, UART_MCR); mcr &= ~UART_MCR_RTS; serial_out(info, UART_MCR, mcr); } break; case TTY_THROTTLE_RQ_AVAIL: info = rs_table + DEV_TO_SL(tty->line); if (I_IXOFF(tty)) { if (info->x_char) info->x_char = 0; else info->x_char = START_CHAR(tty); } else { mcr = serial_in(info, UART_MCR); mcr |= UART_MCR_RTS; serial_out(info, UART_MCR, mcr); } break; } restore_flags(flags); } /* * ------------------------------------------------------------ * rs_ioctl() and friends * ------------------------------------------------------------ */ static int get_serial_info(struct async_struct * info, struct serial_struct * retinfo) { struct serial_struct tmp; if (!retinfo) return -EFAULT; memset(&tmp, 0, sizeof(tmp)); tmp.type = info->type; tmp.line = info->line; tmp.port = info->port; tmp.irq = info->irq; tmp.flags = info->flags; tmp.baud_base = info->baud_base; tmp.close_delay = info->close_delay; tmp.custom_divisor = info->custom_divisor; tmp.hub6 = info->hub6; memcpy_tofs(retinfo,&tmp,sizeof(*retinfo)); return 0; } static int set_serial_info(struct async_struct * info, struct serial_struct * new_info) { struct serial_struct new_serial; struct async_struct old_info; unsigned int i,change_irq,change_port; int retval; struct sigaction sa; if (!new_info) return -EFAULT; memcpy_fromfs(&new_serial,new_info,sizeof(new_serial)); old_info = *info; change_irq = new_serial.irq != info->irq; change_port = (new_serial.port != info->port) || (new_serial.hub6 != info->hub6); if (!suser()) { if (change_irq || change_port || (new_serial.baud_base != info->baud_base) || (new_serial.type != info->type) || (new_serial.close_delay != info->close_delay) || ((new_serial.flags & ~ASYNC_USR_MASK) != (info->flags & ~ASYNC_USR_MASK))) return -EPERM; info->flags = ((info->flags & ~ASYNC_USR_MASK) | (new_serial.flags & ASYNC_USR_MASK)); info->custom_divisor = new_serial.custom_divisor; goto check_and_exit; } if (new_serial.irq == 2) new_serial.irq = 9; if ((new_serial.irq > 15) || (new_serial.port > 0xffff) || (new_serial.type < PORT_UNKNOWN) || (new_serial.type > PORT_MAX)) { return -EINVAL; } /* Make sure address is not already in use */ for (i = 0 ; i < NR_PORTS; i++) if ((info != &rs_table[i]) && (rs_table[i].port == new_serial.port) && rs_table[i].type) return -EADDRINUSE; /* * If necessary, first we try to grab the new IRQ for serial * interrupts. (We have to do this early, since we may get an * error trying to do this.) */ if (new_serial.port && new_serial.type && new_serial.irq && (change_irq || !(info->flags & ASYNC_INITIALIZED))) { if (!IRQ_ports[new_serial.irq]) { sa.sa_handler = rs_interrupt; sa.sa_flags = (SA_INTERRUPT); sa.sa_mask = 0; sa.sa_restorer = NULL; retval = irqaction(new_serial.irq,&sa); if (retval) return retval; } } if ((change_port || change_irq) && (info->count > 1)) return -EBUSY; /* * OK, past this point, all the error checking has been done. * At this point, we start making changes..... */ info->baud_base = new_serial.baud_base; info->flags = ((info->flags & ~ASYNC_FLAGS) | (new_serial.flags & ASYNC_FLAGS)); info->custom_divisor = new_serial.custom_divisor; info->type = new_serial.type; info->close_delay = new_serial.close_delay; if (change_port || change_irq) { /* * We need to shutdown the serial port at the old * port/irq combination. */ shutdown(info, change_irq); info->irq = new_serial.irq; info->port = new_serial.port; info->hub6 = new_serial.hub6; } check_and_exit: if (!info->port || !info->type) return 0; if (info->flags & ASYNC_INITIALIZED) { if (((old_info.flags & ASYNC_SPD_MASK) != (info->flags & ASYNC_SPD_MASK)) || (old_info.custom_divisor != info->custom_divisor)) change_speed(info->line); } else (void) startup(info, 0); return 0; } static int get_modem_info(struct async_struct * info, unsigned int *value) { unsigned char control, status; unsigned int result; cli(); control = serial_in(info, UART_MCR); status = serial_in(info, UART_MSR); sti(); result = ((control & UART_MCR_RTS) ? TIOCM_RTS : 0) | ((control & UART_MCR_DTR) ? TIOCM_DTR : 0) | ((status & UART_MSR_DCD) ? TIOCM_CAR : 0) | ((status & UART_MSR_RI) ? TIOCM_RNG : 0) | ((status & UART_MSR_DSR) ? TIOCM_DSR : 0) | ((status & UART_MSR_CTS) ? TIOCM_CTS : 0); put_fs_long(result,(unsigned long *) value); return 0; } static int set_modem_info(struct async_struct * info, unsigned int cmd, unsigned int *value) { unsigned char control; unsigned int arg = get_fs_long((unsigned long *) value); cli(); control = serial_in(info, UART_MCR); sti(); switch (cmd) { case TIOCMBIS: if (arg & TIOCM_RTS) control |= UART_MCR_RTS; if (arg & TIOCM_DTR) control |= UART_MCR_DTR; break; case TIOCMBIC: if (arg & TIOCM_RTS) control &= ~UART_MCR_RTS; if (arg & TIOCM_DTR) control &= ~UART_MCR_DTR; break; case TIOCMSET: control = (control & ~(UART_MCR_RTS | UART_MCR_DTR)) | ((arg & TIOCM_RTS) ? UART_MCR_RTS : 0) | ((arg & TIOCM_DTR) ? UART_MCR_DTR : 0); break; default: return -EINVAL; } cli(); serial_out(info, UART_MCR, control); sti(); return 0; } static int do_autoconfig(struct async_struct * info) { int retval; if (!suser()) return -EPERM; if (info->count > 1) return -EBUSY; shutdown(info, 1); cli(); autoconfig(info); sti(); retval = startup(info, 1); if (retval) return retval; return 0; } /* * This routine sends a break character out the serial port. */ static void send_break( struct async_struct * info, int duration) { if (!info->port) return; current->state = TASK_INTERRUPTIBLE; current->timeout = jiffies + duration; cli(); serial_out(info, UART_LCR, serial_inp(info, UART_LCR) | UART_LCR_SBC); schedule(); serial_out(info, UART_LCR, serial_inp(info, UART_LCR) & ~UART_LCR_SBC); sti(); } /* * This routine returns a bitfield of "wild interrupts". Basically, * any unclaimed interrupts which is flapping around. */ static int check_wild_interrupts(int doprint) { int i, mask; int wild_interrupts = 0; int irq_lines; unsigned long timeout; unsigned long flags; /* Turn on interrupts (they may be off) */ save_flags(flags); sti(); irq_lines = grab_all_interrupts(0); /* * Delay for 0.1 seconds -- we use a busy loop since this may * occur during the bootup sequence */ timeout = jiffies+10; while (timeout >= jiffies) ; rs_triggered = 0; /* Reset after letting things settle */ timeout = jiffies+10; while (timeout >= jiffies) ; for (i = 0, mask = 1; i < 16; i++, mask <<= 1) { if ((rs_triggered & (1 << i)) && (irq_lines & (1 << i))) { wild_interrupts |= mask; if (doprint) printk("Wild interrupt? (IRQ %d)\n", i); } } free_all_interrupts(irq_lines); restore_flags(flags); return wild_interrupts; } static int rs_ioctl(struct tty_struct *tty, struct file * file, unsigned int cmd, unsigned long arg) { int error, line; struct async_struct * info; line = DEV_TO_SL(tty->line); if (line < 0 || line >= NR_PORTS) return -ENODEV; info = rs_table + line; switch (cmd) { case TCSBRK: /* SVID version: non-zero arg --> no break */ if (!arg) send_break(info, HZ/4); /* 1/4 second */ return 0; case TCSBRKP: /* support for POSIX tcsendbreak() */ send_break(info, arg ? arg*(HZ/10) : HZ/4); return 0; case TIOCGSOFTCAR: error = verify_area(VERIFY_WRITE, (void *) arg,sizeof(long)); if (error) return error; put_fs_long(C_CLOCAL(tty) ? 1 : 0, (unsigned long *) arg); return 0; case TIOCSSOFTCAR: arg = get_fs_long((unsigned long *) arg); tty->termios->c_cflag = ((tty->termios->c_cflag & ~CLOCAL) | (arg ? CLOCAL : 0)); return 0; case TIOCMGET: error = verify_area(VERIFY_WRITE, (void *) arg, sizeof(unsigned int)); if (error) return error; return get_modem_info(info, (unsigned int *) arg); case TIOCMBIS: case TIOCMBIC: case TIOCMSET: return set_modem_info(info, cmd, (unsigned int *) arg); case TIOCGSERIAL: error = verify_area(VERIFY_WRITE, (void *) arg, sizeof(struct serial_struct)); if (error) return error; return get_serial_info(info, (struct serial_struct *) arg); case TIOCSSERIAL: return set_serial_info(info, (struct serial_struct *) arg); case TIOCSERCONFIG: return do_autoconfig(info); case TIOCSERGWILD: error = verify_area(VERIFY_WRITE, (void *) arg, sizeof(int)); if (error) return error; put_fs_long(rs_wild_int_mask, (unsigned long *) arg); return 0; case TIOCSERSWILD: if (!suser()) return -EPERM; rs_wild_int_mask = get_fs_long((unsigned long *) arg); if (rs_wild_int_mask < 0) rs_wild_int_mask = check_wild_interrupts(0); return 0; default: return -EINVAL; } return 0; } static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios) { struct async_struct *info; if (tty->termios->c_cflag == old_termios->c_cflag) return; info = &rs_table[DEV_TO_SL(tty->line)]; change_speed(DEV_TO_SL(tty->line)); if ((old_termios->c_cflag & CRTSCTS) && !(tty->termios->c_cflag & CRTSCTS)) { tty->hw_stopped = 0; rs_write(tty); } if (!(old_termios->c_cflag & CLOCAL) && (tty->termios->c_cflag & CLOCAL)) wake_up_interruptible(&info->open_wait); if (I_INPCK(tty)) info->read_status_mask = (UART_LSR_OE | UART_LSR_BI | UART_LSR_FE | UART_LSR_PE); else info->read_status_mask = (UART_LSR_OE | UART_LSR_BI | UART_LSR_FE); } /* * ------------------------------------------------------------ * rs_close() * * This routine is called when the serial port gets closed. First, we * wait for the last remaining data to be sent. Then, we unlink its * async structure from the interrupt chain if necessary, and we free * that IRQ if nothing is left in the chain. * ------------------------------------------------------------ */ static void rs_close(struct tty_struct *tty, struct file * filp) { struct async_struct * info; int line; if (tty_hung_up_p(filp)) return; line = DEV_TO_SL(tty->line); if ((line < 0) || (line >= NR_PORTS)) return; info = rs_table + line; #ifdef SERIAL_DEBUG_OPEN printk("rs_close ttys%d, count = %d\n", info->line, info->count); #endif if ((tty->count == 1) && (info->count != 1)) { /* * Uh, oh. tty->count is 1, which means that the tty * structure will be freed. Info->count should always * be one in these conditions. If it's greater than * one, we've got real problems, since it means the * serial port won't be shutdown. */ printk("rs_close: bad serial port count; tty->count is 1, " "info->count is %d\n", info->count); info->count = 1; } if (--info->count < 0) { printk("rs_close: bad serial port count for ttys%d: %d\n", info->line, info->count); info->count = 0; } if (info->count) return; info->flags |= ASYNC_CLOSING; /* * Save the termios structure, since this port may have * separate termios for callout and dialin. */ if (info->flags & ASYNC_NORMAL_ACTIVE) info->normal_termios = *tty->termios; if (info->flags & ASYNC_CALLOUT_ACTIVE) info->callout_termios = *tty->termios; tty->stopped = 0; /* Force flush to succeed */ tty->hw_stopped = 0; if (info->flags & ASYNC_INITIALIZED) { rs_start(tty); /* * XXX There should be a timeout added to * wait_until_sent, eventually. TYT 1/19/94 */ wait_until_sent(tty); } else flush_output(tty); flush_input(tty); cli(); /* * Make sure the UART transmitter has completely drained; this * is especially important if there is a transmit FIFO! */ if (!(serial_inp(info, UART_LSR) & UART_LSR_THRE)) { rs_start(tty); /* Make sure THRI interrupt enabled */ interruptible_sleep_on(&info->xmit_wait); } sti(); shutdown(info, 1); clear_bit(line, rs_event); info->event = 0; info->tty = 0; if (info->blocked_open) { if (info->close_delay) { tty->count++; /* avoid race condition */ current->state = TASK_INTERRUPTIBLE; current->timeout = jiffies + info->close_delay; schedule(); tty->count--; } wake_up_interruptible(&info->open_wait); } info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CALLOUT_ACTIVE| ASYNC_CLOSING); wake_up_interruptible(&info->close_wait); } /* * rs_hangup() --- called by tty_hangup() when a hangup is signaled. */ void rs_hangup(struct tty_struct *tty) { struct async_struct * info; int line; line = DEV_TO_SL(tty->line); if ((line < 0) || (line >= NR_PORTS)) return; info = rs_table + line; shutdown(info, 1); clear_bit(line, rs_event); info->event = 0; info->count = 0; info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CALLOUT_ACTIVE); info->tty = 0; wake_up_interruptible(&info->open_wait); } /* * ------------------------------------------------------------ * rs_open() and friends * ------------------------------------------------------------ */ static int block_til_ready(struct tty_struct *tty, struct file * filp, struct async_struct *info) { struct wait_queue wait = { current, NULL }; int retval; int do_clocal = C_CLOCAL(tty); /* * If the device is in the middle of being closed, then block * until it's done, and then try again. */ if (info->flags & ASYNC_CLOSING) { interruptible_sleep_on(&info->close_wait); #ifdef SERIAL_DO_RESTART if (info->flags & ASYNC_HUP_NOTIFY) return -EAGAIN; else return -ERESTARTSYS; #else return -EAGAIN; #endif } /* * If this is a callout device, then just make sure the normal * device isn't being used. */ if (MAJOR(filp->f_rdev) == TTYAUX_MAJOR) { if (info->flags & ASYNC_NORMAL_ACTIVE) return -EBUSY; if ((info->flags & ASYNC_CALLOUT_ACTIVE) && (info->flags & ASYNC_SESSION_LOCKOUT) && (info->session != current->session)) return -EBUSY; if ((info->flags & ASYNC_CALLOUT_ACTIVE) && (info->flags & ASYNC_PGRP_LOCKOUT) && (info->pgrp != current->pgrp)) return -EBUSY; info->flags |= ASYNC_CALLOUT_ACTIVE; return 0; } /* * If non-blocking mode is set, then make the check up front * and then exit. */ if (filp->f_flags & O_NONBLOCK) { if (info->flags & ASYNC_CALLOUT_ACTIVE) return -EBUSY; info->flags |= ASYNC_NORMAL_ACTIVE; return 0; } /* * Block waiting for the carrier detect and the line to become * free (i.e., not in use by the callout). While we are in * this loop, info->count is dropped by one, so that * rs_close() knows when to free things. We restore it upon * exit, either normal or abnormal. */ retval = 0; add_wait_queue(&info->open_wait, &wait); #ifdef SERIAL_DEBUG_OPEN printk("block_til_ready before block: ttys%d, count = %d\n", info->line, info->count); #endif info->count--; info->blocked_open++; while (1) { cli(); if (!(info->flags & ASYNC_CALLOUT_ACTIVE)) serial_out(info, UART_MCR, serial_inp(info, UART_MCR) | (UART_MCR_DTR | UART_MCR_RTS)); sti(); current->state = TASK_INTERRUPTIBLE; if (tty_hung_up_p(filp) || !(info->flags & ASYNC_INITIALIZED)) { #ifdef SERIAL_DO_RESTART if (info->flags & ASYNC_HUP_NOTIFY) retval = -EAGAIN; else retval = -ERESTARTSYS; #else retval = -EAGAIN; #endif break; } if (!(info->flags & ASYNC_CALLOUT_ACTIVE) && !(info->flags & ASYNC_CLOSING) && (do_clocal || (serial_in(info, UART_MSR) & UART_MSR_DCD))) break; if (current->signal & ~current->blocked) { retval = -ERESTARTSYS; break; } #ifdef SERIAL_DEBUG_OPEN printk("block_til_ready blocking: ttys%d, count = %d\n", info->line, info->count); #endif schedule(); } current->state = TASK_RUNNING; remove_wait_queue(&info->open_wait, &wait); if (!tty_hung_up_p(filp)) info->count++; info->blocked_open--; #ifdef SERIAL_DEBUG_OPEN printk("block_til_ready after blocking: ttys%d, count = %d\n", info->line, info->count); #endif if (retval) return retval; info->flags |= ASYNC_NORMAL_ACTIVE; return 0; } /* * This routine is called whenever a serial port is opened. It * enables interrupts for a serial port, linking in its async structure into * the IRQ chain. It also performs the serial-speicific * initalization for the tty structure. */ int rs_open(struct tty_struct *tty, struct file * filp) { struct async_struct *info; int retval, line; line = DEV_TO_SL(tty->line); if ((line < 0) || (line >= NR_PORTS)) return -ENODEV; info = rs_table + line; #ifdef SERIAL_DEBUG_OPEN printk("rs_open ttys%d, count = %d\n", info->line, info->count); #endif info->count++; info->tty = tty; tty->write = rs_write; tty->close = rs_close; tty->ioctl = rs_ioctl; tty->throttle = rs_throttle; tty->set_termios = rs_set_termios; tty->stop = rs_stop; tty->start = rs_start; tty->hangup = rs_hangup; if ((info->count == 1) && (info->flags & ASYNC_SPLIT_TERMIOS)) { if (MAJOR(filp->f_rdev) == TTY_MAJOR) *tty->termios = info->normal_termios; else *tty->termios = info->callout_termios; } /* * Start up serial port */ retval = startup(info, 1); if (retval) return retval; retval = block_til_ready(tty, filp, info); if (retval) { #ifdef SERIAL_DEBUG_OPEN printk("rs_open returning after block_til_ready with %d\n", retval); #endif return retval; } info->session = current->session; info->pgrp = current->pgrp; #ifdef SERIAL_DEBUG_OPEN printk("rs_open ttys%d successful...", info->line); #endif return 0; } /* * --------------------------------------------------------------------- * rs_init() and friends * * rs_init() is called at boot-time to initialize the serial driver. * --------------------------------------------------------------------- */ /* * This routine prints out the appropriate serial driver version * number, and identifies which options were configured into this * driver. */ static void show_serial_version(void) { printk("Serial driver version 3.99a with"); #ifdef CONFIG_AST_FOURPORT printk(" AST_FOURPORT"); #define SERIAL_OPT #endif #ifdef CONFIG_ACCENT_ASYNC printk(" ACCENT_ASYNC"); #define SERIAL_OPT #endif #ifdef CONFIG_HUB6 printk(" HUB-6"); #define SERIAL_OPT #endif #ifdef CONFIG_AUTO_IRQ printk (" AUTO_IRQ"); #define SERIAL_OPT #endif #ifdef SERIAL_OPT printk(" enabled\n"); #else printk(" no serial options enabled\n"); #endif #undef SERIAL_OPT } /* * This routine is called by do_auto_irq(); it attempts to determine * which interrupt a serial port is configured to use. It is not * fool-proof, but it works a large part of the time. */ static int get_auto_irq(struct async_struct *info) { unsigned char save_MCR, save_IER, save_ICP=0; unsigned short ICP=0, port = info->port; unsigned long timeout; /* * Enable interrupts and see who answers */ rs_irq_triggered = 0; cli(); save_IER = serial_inp(info, UART_IER); save_MCR = serial_inp(info, UART_MCR); if (info->flags & ASYNC_FOURPORT) { serial_outp(info, UART_MCR, UART_MCR_DTR | UART_MCR_RTS); serial_outp(info, UART_IER, 0x0f); /* enable all intrs */ ICP = (port & 0xFE0) | 0x01F; save_ICP = inb_p(ICP); outb_p(0x80, ICP); (void) inb_p(ICP); } else { serial_outp(info, UART_MCR, UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2); serial_outp(info, UART_IER, 0x0f); /* enable all intrs */ } sti(); /* * Next, clear the interrupt registers. */ (void)serial_inp(info, UART_LSR); (void)serial_inp(info, UART_RX); (void)serial_inp(info, UART_IIR); (void)serial_inp(info, UART_MSR); timeout = jiffies+2; while (timeout >= jiffies) { if (rs_irq_triggered) break; } /* * Now check to see if we got any business, and clean up. */ cli(); serial_outp(info, UART_IER, save_IER); serial_outp(info, UART_MCR, save_MCR); if (info->flags & ASYNC_FOURPORT) outb_p(save_ICP, ICP); sti(); return(rs_irq_triggered); } /* * Calls get_auto_irq() multiple times, to make sure we don't get * faked out by random interrupts */ static int do_auto_irq(struct async_struct * info) { unsigned port = info->port; int irq_lines = 0; int irq_try_1 = 0, irq_try_2 = 0; int retries; unsigned long flags; if (!port) return 0; /* Turn on interrupts (they may be off) */ save_flags(flags); sti(); irq_lines = grab_all_interrupts(rs_wild_int_mask); for (retries = 0; retries < 5; retries++) { if (!irq_try_1) irq_try_1 = get_auto_irq(info); if (!irq_try_2) irq_try_2 = get_auto_irq(info); if (irq_try_1 && irq_try_2) { if (irq_try_1 == irq_try_2) break; irq_try_1 = irq_try_2 = 0; } } restore_flags(flags); free_all_interrupts(irq_lines); return (irq_try_1 == irq_try_2) ? irq_try_1 : 0; } /* * This routine is called by rs_init() to initialize a specific serial * port. It determines what type of UART ship this serial port is * using: 8250, 16450, 16550, 16550A. The important question is * whether or not this UART is a 16550A or not, since this will * determine whether or not we can use its FIFO features or not. */ static void autoconfig(struct async_struct * info) { unsigned char status1, status2, scratch, scratch2; unsigned port = info->port; unsigned long flags; info->type = PORT_UNKNOWN; if (!port) return; save_flags(flags); cli(); /* * Do a simple existence test first; if we fail this, there's * no point trying anything else. */ scratch = serial_inp(info, UART_IER); serial_outp(info, UART_IER, 0); scratch2 = serial_inp(info, UART_IER); serial_outp(info, UART_IER, scratch); if (scratch2) { restore_flags(flags); return; /* We failed; there's nothing here */ } /* * Check to see if a UART is really there. Certain broken * internal modems based on the Rockwell chipset fail this * test, because they apparently don't implement the loopback * test mode. So this test is skipped on the COM 1 through * COM 4 ports. This *should* be safe, since no board * manufactucturer would be stupid enough to design a board * that conflicts with COM 1-4 --- we hope! */ if (!(info->flags & ASYNC_SKIP_TEST)) { scratch = serial_inp(info, UART_MCR); serial_outp(info, UART_MCR, UART_MCR_LOOP | scratch); scratch2 = serial_inp(info, UART_MSR); serial_outp(info, UART_MCR, UART_MCR_LOOP | 0x0A); status1 = serial_inp(info, UART_MSR) & 0xF0; serial_outp(info, UART_MCR, scratch); serial_outp(info, UART_MSR, scratch2); if (status1 != 0x90) { restore_flags(flags); return; } } /* * If the AUTO_IRQ flag is set, try to do the automatic IRQ * detection. */ if (info->flags & ASYNC_AUTO_IRQ) info->irq = do_auto_irq(info); serial_outp(info, UART_FCR, UART_FCR_ENABLE_FIFO); scratch = serial_in(info, UART_IIR) >> 6; info->xmit_fifo_size = 1; switch (scratch) { case 0: info->type = PORT_16450; break; case 1: info->type = PORT_UNKNOWN; break; case 2: info->type = PORT_16550; break; case 3: info->type = PORT_16550A; info->xmit_fifo_size = 16; break; } if (info->type == PORT_16450) { scratch = serial_in(info, UART_SCR); serial_outp(info, UART_SCR, 0xa5); status1 = serial_in(info, UART_SCR); serial_outp(info, UART_SCR, 0x5a); status2 = serial_in(info, UART_SCR); serial_outp(info, UART_SCR, scratch); if ((status1 != 0xa5) || (status2 != 0x5a)) info->type = PORT_8250; } /* * Reset the UART. */ serial_outp(info, UART_MCR, 0x00); serial_outp(info, UART_FCR, (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT)); (void)serial_in(info, UART_RX); restore_flags(flags); } /* * The serial driver boot-time initialization code! */ long rs_init(long kmem_start) { int i; struct async_struct * info; memset(&rs_event, 0, sizeof(rs_event)); bh_base[SERIAL_BH].routine = do_softint; timer_table[RS_TIMER].fn = rs_timer; timer_table[RS_TIMER].expires = 0; IRQ_active = 0; #ifdef CONFIG_AUTO_IRQ rs_wild_int_mask = check_wild_interrupts(1); #endif for (i = 0; i < 16; i++) { IRQ_ports[i] = 0; IRQ_timeout[i] = 0; } show_serial_version(); for (i = 0, info = rs_table; i < NR_PORTS; i++,info++) { info->line = i; info->tty = 0; info->type = PORT_UNKNOWN; info->custom_divisor = 0; info->close_delay = 50; info->x_char = 0; info->event = 0; info->count = 0; info->blocked_open = 0; memset(&info->callout_termios, 0, sizeof(struct termios)); memset(&info->normal_termios, 0, sizeof(struct termios)); info->open_wait = 0; info->xmit_wait = 0; info->close_wait = 0; info->next_port = 0; info->prev_port = 0; if (info->irq == 2) info->irq = 9; if (!(info->flags & ASYNC_BOOT_AUTOCONF)) continue; autoconfig(info); if (info->type == PORT_UNKNOWN) continue; printk("tty%02d%s at 0x%04x (irq = %d)", info->line, (info->flags & ASYNC_FOURPORT) ? " FourPort" : "", info->port, info->irq); switch (info->type) { case PORT_8250: printk(" is a 8250\n"); break; case PORT_16450: printk(" is a 16450\n"); break; case PORT_16550: printk(" is a 16550\n"); break; case PORT_16550A: printk(" is a 16550A\n"); break; default: printk("\n"); break; } } return kmem_start; }