diff options
Diffstat (limited to 'drivers/char/generic_serial.c')
| -rw-r--r-- | drivers/char/generic_serial.c | 1001 |
1 files changed, 1001 insertions, 0 deletions
diff --git a/drivers/char/generic_serial.c b/drivers/char/generic_serial.c new file mode 100644 index 00000000000..204a7302a4a --- /dev/null +++ b/drivers/char/generic_serial.c @@ -0,0 +1,1001 @@ +/* + * generic_serial.c + * + * Copyright (C) 1998/1999 R.E.Wolff@BitWizard.nl + * + * written for the SX serial driver. + * Contains the code that should be shared over all the serial drivers. + * + * Credit for the idea to do it this way might go to Alan Cox. + * + * + * Version 0.1 -- December, 1998. Initial version. + * Version 0.2 -- March, 1999. Some more routines. Bugfixes. Etc. + * Version 0.5 -- August, 1999. Some more fixes. Reformat for Linus. + * + * BitWizard is actively maintaining this file. We sometimes find + * that someone submitted changes to this file. We really appreciate + * your help, but please submit changes through us. We're doing our + * best to be responsive. -- REW + * */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/tty.h> +#include <linux/serial.h> +#include <linux/mm.h> +#include <linux/generic_serial.h> +#include <linux/interrupt.h> +#include <linux/tty_flip.h> +#include <linux/delay.h> +#include <asm/semaphore.h> +#include <asm/uaccess.h> + +#define DEBUG + +static char * tmp_buf; +static DECLARE_MUTEX(tmp_buf_sem); + +static int gs_debug; + +#ifdef DEBUG +#define gs_dprintk(f, str...) if (gs_debug & f) printk (str) +#else +#define gs_dprintk(f, str...) /* nothing */ +#endif + +#define func_enter() gs_dprintk (GS_DEBUG_FLOW, "gs: enter %s\n", __FUNCTION__) +#define func_exit() gs_dprintk (GS_DEBUG_FLOW, "gs: exit %s\n", __FUNCTION__) +#define NEW_WRITE_LOCKING 1 +#if NEW_WRITE_LOCKING +#define DECL /* Nothing */ +#define LOCKIT down (& port->port_write_sem); +#define RELEASEIT up (&port->port_write_sem); +#else +#define DECL unsigned long flags; +#define LOCKIT save_flags (flags);cli () +#define RELEASEIT restore_flags (flags) +#endif + +#define RS_EVENT_WRITE_WAKEUP 1 + +module_param(gs_debug, int, 0644); + + +void gs_put_char(struct tty_struct * tty, unsigned char ch) +{ + struct gs_port *port; + DECL + + func_enter (); + + if (!tty) return; + + port = tty->driver_data; + + if (!port) return; + + if (! (port->flags & ASYNC_INITIALIZED)) return; + + /* Take a lock on the serial tranmit buffer! */ + LOCKIT; + + if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1) { + /* Sorry, buffer is full, drop character. Update statistics???? -- REW */ + RELEASEIT; + return; + } + + port->xmit_buf[port->xmit_head++] = ch; + port->xmit_head &= SERIAL_XMIT_SIZE - 1; + port->xmit_cnt++; /* Characters in buffer */ + + RELEASEIT; + func_exit (); +} + + +#ifdef NEW_WRITE_LOCKING + +/* +> Problems to take into account are: +> -1- Interrupts that empty part of the buffer. +> -2- page faults on the access to userspace. +> -3- Other processes that are also trying to do a "write". +*/ + +int gs_write(struct tty_struct * tty, + const unsigned char *buf, int count) +{ + struct gs_port *port; + int c, total = 0; + int t; + + func_enter (); + + if (!tty) return 0; + + port = tty->driver_data; + + if (!port) return 0; + + if (! (port->flags & ASYNC_INITIALIZED)) + return 0; + + /* get exclusive "write" access to this port (problem 3) */ + /* This is not a spinlock because we can have a disk access (page + fault) in copy_from_user */ + down (& port->port_write_sem); + + while (1) { + + c = count; + + /* This is safe because we "OWN" the "head". Noone else can + change the "head": we own the port_write_sem. */ + /* Don't overrun the end of the buffer */ + t = SERIAL_XMIT_SIZE - port->xmit_head; + if (t < c) c = t; + + /* This is safe because the xmit_cnt can only decrease. This + would increase "t", so we might copy too little chars. */ + /* Don't copy past the "head" of the buffer */ + t = SERIAL_XMIT_SIZE - 1 - port->xmit_cnt; + if (t < c) c = t; + + /* Can't copy more? break out! */ + if (c <= 0) break; + + memcpy (port->xmit_buf + port->xmit_head, buf, c); + + port -> xmit_cnt += c; + port -> xmit_head = (port->xmit_head + c) & (SERIAL_XMIT_SIZE -1); + buf += c; + count -= c; + total += c; + } + up (& port->port_write_sem); + + gs_dprintk (GS_DEBUG_WRITE, "write: interrupts are %s\n", + (port->flags & GS_TX_INTEN)?"enabled": "disabled"); + + if (port->xmit_cnt && + !tty->stopped && + !tty->hw_stopped && + !(port->flags & GS_TX_INTEN)) { + port->flags |= GS_TX_INTEN; + port->rd->enable_tx_interrupts (port); + } + func_exit (); + return total; +} +#else +/* +> Problems to take into account are: +> -1- Interrupts that empty part of the buffer. +> -2- page faults on the access to userspace. +> -3- Other processes that are also trying to do a "write". +*/ + +int gs_write(struct tty_struct * tty, + const unsigned char *buf, int count) +{ + struct gs_port *port; + int c, total = 0; + int t; + unsigned long flags; + + func_enter (); + + /* The standard serial driver returns 0 in this case. + That sounds to me as "No error, I just didn't get to writing any + bytes. Feel free to try again." + The "official" way to write n bytes from buf is: + + for (nwritten = 0;nwritten < n;nwritten += rv) { + rv = write (fd, buf+nwritten, n-nwritten); + if (rv < 0) break; // Error: bail out. // + } + + which will loop endlessly in this case. The manual page for write + agrees with me. In practise almost everybody writes + "write (fd, buf,n);" but some people might have had to deal with + incomplete writes in the past and correctly implemented it by now... + */ + + if (!tty) return -EIO; + + port = tty->driver_data; + if (!port || !port->xmit_buf || !tmp_buf) + return -EIO; + + local_save_flags(flags); + while (1) { + cli(); + c = count; + + /* This is safe because we "OWN" the "head". Noone else can + change the "head": we own the port_write_sem. */ + /* Don't overrun the end of the buffer */ + t = SERIAL_XMIT_SIZE - port->xmit_head; + if (t < c) c = t; + + /* This is safe because the xmit_cnt can only decrease. This + would increase "t", so we might copy too little chars. */ + /* Don't copy past the "head" of the buffer */ + t = SERIAL_XMIT_SIZE - 1 - port->xmit_cnt; + if (t < c) c = t; + + /* Can't copy more? break out! */ + if (c <= 0) { + local_restore_flags(flags); + break; + } + memcpy(port->xmit_buf + port->xmit_head, buf, c); + port->xmit_head = ((port->xmit_head + c) & + (SERIAL_XMIT_SIZE-1)); + port->xmit_cnt += c; + local_restore_flags(flags); + buf += c; + count -= c; + total += c; + } + + if (port->xmit_cnt && + !tty->stopped && + !tty->hw_stopped && + !(port->flags & GS_TX_INTEN)) { + port->flags |= GS_TX_INTEN; + port->rd->enable_tx_interrupts (port); + } + func_exit (); + return total; +} + +#endif + + + +int gs_write_room(struct tty_struct * tty) +{ + struct gs_port *port = tty->driver_data; + int ret; + + func_enter (); + ret = SERIAL_XMIT_SIZE - port->xmit_cnt - 1; + if (ret < 0) + ret = 0; + func_exit (); + return ret; +} + + +int gs_chars_in_buffer(struct tty_struct *tty) +{ + struct gs_port *port = tty->driver_data; + func_enter (); + + func_exit (); + return port->xmit_cnt; +} + + +static int gs_real_chars_in_buffer(struct tty_struct *tty) +{ + struct gs_port *port; + func_enter (); + + if (!tty) return 0; + port = tty->driver_data; + + if (!port->rd) return 0; + if (!port->rd->chars_in_buffer) return 0; + + func_exit (); + return port->xmit_cnt + port->rd->chars_in_buffer (port); +} + + +static int gs_wait_tx_flushed (void * ptr, unsigned long timeout) +{ + struct gs_port *port = ptr; + unsigned long end_jiffies; + int jiffies_to_transmit, charsleft = 0, rv = 0; + int rcib; + + func_enter(); + + gs_dprintk (GS_DEBUG_FLUSH, "port=%p.\n", port); + if (port) { + gs_dprintk (GS_DEBUG_FLUSH, "xmit_cnt=%x, xmit_buf=%p, tty=%p.\n", + port->xmit_cnt, port->xmit_buf, port->tty); + } + + if (!port || port->xmit_cnt < 0 || !port->xmit_buf) { + gs_dprintk (GS_DEBUG_FLUSH, "ERROR: !port, !port->xmit_buf or prot->xmit_cnt < 0.\n"); + func_exit(); + return -EINVAL; /* This is an error which we don't know how to handle. */ + } + + rcib = gs_real_chars_in_buffer(port->tty); + + if(rcib <= 0) { + gs_dprintk (GS_DEBUG_FLUSH, "nothing to wait for.\n"); + func_exit(); + return rv; + } + /* stop trying: now + twice the time it would normally take + seconds */ + if (timeout == 0) timeout = MAX_SCHEDULE_TIMEOUT; + end_jiffies = jiffies; + if (timeout != MAX_SCHEDULE_TIMEOUT) + end_jiffies += port->baud?(2 * rcib * 10 * HZ / port->baud):0; + end_jiffies += timeout; + + gs_dprintk (GS_DEBUG_FLUSH, "now=%lx, end=%lx (%ld).\n", + jiffies, end_jiffies, end_jiffies-jiffies); + + /* the expression is actually jiffies < end_jiffies, but that won't + work around the wraparound. Tricky eh? */ + while ((charsleft = gs_real_chars_in_buffer (port->tty)) && + time_after (end_jiffies, jiffies)) { + /* Units check: + chars * (bits/char) * (jiffies /sec) / (bits/sec) = jiffies! + check! */ + + charsleft += 16; /* Allow 16 chars more to be transmitted ... */ + jiffies_to_transmit = port->baud?(1 + charsleft * 10 * HZ / port->baud):0; + /* ^^^ Round up.... */ + if (jiffies_to_transmit <= 0) jiffies_to_transmit = 1; + + gs_dprintk (GS_DEBUG_FLUSH, "Expect to finish in %d jiffies " + "(%d chars).\n", jiffies_to_transmit, charsleft); + + msleep_interruptible(jiffies_to_msecs(jiffies_to_transmit)); + if (signal_pending (current)) { + gs_dprintk (GS_DEBUG_FLUSH, "Signal pending. Bombing out: "); + rv = -EINTR; + break; + } + } + + gs_dprintk (GS_DEBUG_FLUSH, "charsleft = %d.\n", charsleft); + set_current_state (TASK_RUNNING); + + func_exit(); + return rv; +} + + + +void gs_flush_buffer(struct tty_struct *tty) +{ + struct gs_port *port; + unsigned long flags; + + func_enter (); + + if (!tty) return; + + port = tty->driver_data; + + if (!port) return; + + /* XXX Would the write semaphore do? */ + spin_lock_irqsave (&port->driver_lock, flags); + port->xmit_cnt = port->xmit_head = port->xmit_tail = 0; + spin_unlock_irqrestore (&port->driver_lock, flags); + + wake_up_interruptible(&tty->write_wait); + tty_wakeup(tty); + func_exit (); +} + + +void gs_flush_chars(struct tty_struct * tty) +{ + struct gs_port *port; + + func_enter (); + + if (!tty) return; + + port = tty->driver_data; + + if (!port) return; + + if (port->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped || + !port->xmit_buf) { + func_exit (); + return; + } + + /* Beats me -- REW */ + port->flags |= GS_TX_INTEN; + port->rd->enable_tx_interrupts (port); + func_exit (); +} + + +void gs_stop(struct tty_struct * tty) +{ + struct gs_port *port; + + func_enter (); + + if (!tty) return; + + port = tty->driver_data; + + if (!port) return; + + if (port->xmit_cnt && + port->xmit_buf && + (port->flags & GS_TX_INTEN) ) { + port->flags &= ~GS_TX_INTEN; + port->rd->disable_tx_interrupts (port); + } + func_exit (); +} + + +void gs_start(struct tty_struct * tty) +{ + struct gs_port *port; + + if (!tty) return; + + port = tty->driver_data; + + if (!port) return; + + if (port->xmit_cnt && + port->xmit_buf && + !(port->flags & GS_TX_INTEN) ) { + port->flags |= GS_TX_INTEN; + port->rd->enable_tx_interrupts (port); + } + func_exit (); +} + + +static void gs_shutdown_port (struct gs_port *port) +{ + unsigned long flags; + + func_enter(); + + if (!port) return; + + if (!(port->flags & ASYNC_INITIALIZED)) + return; + + spin_lock_irqsave(&port->driver_lock, flags); + + if (port->xmit_buf) { + free_page((unsigned long) port->xmit_buf); + port->xmit_buf = NULL; + } + + if (port->tty) + set_bit(TTY_IO_ERROR, &port->tty->flags); + + port->rd->shutdown_port (port); + + port->flags &= ~ASYNC_INITIALIZED; + spin_unlock_irqrestore(&port->driver_lock, flags); + + func_exit(); +} + + +void gs_hangup(struct tty_struct *tty) +{ + struct gs_port *port; + + func_enter (); + + if (!tty) return; + + port = tty->driver_data; + tty = port->tty; + if (!tty) + return; + + gs_shutdown_port (port); + port->flags &= ~(ASYNC_NORMAL_ACTIVE|GS_ACTIVE); + port->tty = NULL; + port->count = 0; + + wake_up_interruptible(&port->open_wait); + func_exit (); +} + + +int gs_block_til_ready(void *port_, struct file * filp) +{ + struct gs_port *port = port_; + DECLARE_WAITQUEUE(wait, current); + int retval; + int do_clocal = 0; + int CD; + struct tty_struct *tty; + unsigned long flags; + + func_enter (); + + if (!port) return 0; + + tty = port->tty; + + if (!tty) return 0; + + gs_dprintk (GS_DEBUG_BTR, "Entering gs_block_till_ready.\n"); + /* + * If the device is in the middle of being closed, then block + * until it's done, and then try again. + */ + if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) { + interruptible_sleep_on(&port->close_wait); + if (port->flags & ASYNC_HUP_NOTIFY) + return -EAGAIN; + else + return -ERESTARTSYS; + } + + gs_dprintk (GS_DEBUG_BTR, "after hung up\n"); + + /* + * If non-blocking mode is set, or the port is not enabled, + * then make the check up front and then exit. + */ + if ((filp->f_flags & O_NONBLOCK) || + (tty->flags & (1 << TTY_IO_ERROR))) { + port->flags |= ASYNC_NORMAL_ACTIVE; + return 0; + } + + gs_dprintk (GS_DEBUG_BTR, "after nonblock\n"); + + if (C_CLOCAL(tty)) + do_clocal = 1; + + /* + * 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, port->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(&port->open_wait, &wait); + + gs_dprintk (GS_DEBUG_BTR, "after add waitq.\n"); + spin_lock_irqsave(&port->driver_lock, flags); + if (!tty_hung_up_p(filp)) { + port->count--; + } + spin_unlock_irqrestore(&port->driver_lock, flags); + port->blocked_open++; + while (1) { + CD = port->rd->get_CD (port); + gs_dprintk (GS_DEBUG_BTR, "CD is now %d.\n", CD); + set_current_state (TASK_INTERRUPTIBLE); + if (tty_hung_up_p(filp) || + !(port->flags & ASYNC_INITIALIZED)) { + if (port->flags & ASYNC_HUP_NOTIFY) + retval = -EAGAIN; + else + retval = -ERESTARTSYS; + break; + } + if (!(port->flags & ASYNC_CLOSING) && + (do_clocal || CD)) + break; + gs_dprintk (GS_DEBUG_BTR, "signal_pending is now: %d (%lx)\n", + (int)signal_pending (current), *(long*)(¤t->blocked)); + if (signal_pending(current)) { + retval = -ERESTARTSYS; + break; + } + schedule(); + } + gs_dprintk (GS_DEBUG_BTR, "Got out of the loop. (%d)\n", + port->blocked_open); + set_current_state (TASK_RUNNING); + remove_wait_queue(&port->open_wait, &wait); + if (!tty_hung_up_p(filp)) { + port->count++; + } + port->blocked_open--; + if (retval) + return retval; + + port->flags |= ASYNC_NORMAL_ACTIVE; + func_exit (); + return 0; +} + + +void gs_close(struct tty_struct * tty, struct file * filp) +{ + unsigned long flags; + struct gs_port *port; + + func_enter (); + + if (!tty) return; + + port = (struct gs_port *) tty->driver_data; + + if (!port) return; + + if (!port->tty) { + /* This seems to happen when this is called from vhangup. */ + gs_dprintk (GS_DEBUG_CLOSE, "gs: Odd: port->tty is NULL\n"); + port->tty = tty; + } + + spin_lock_irqsave(&port->driver_lock, flags); + + if (tty_hung_up_p(filp)) { + spin_unlock_irqrestore(&port->driver_lock, flags); + if (port->rd->hungup) + port->rd->hungup (port); + func_exit (); + return; + } + + if ((tty->count == 1) && (port->count != 1)) { + printk(KERN_ERR "gs: gs_close port %p: bad port count;" + " tty->count is 1, port count is %d\n", port, port->count); + port->count = 1; + } + if (--port->count < 0) { + printk(KERN_ERR "gs: gs_close port %p: bad port count: %d\n", port, port->count); + port->count = 0; + } + + if (port->count) { + gs_dprintk(GS_DEBUG_CLOSE, "gs_close port %p: count: %d\n", port, port->count); + spin_unlock_irqrestore(&port->driver_lock, flags); + func_exit (); + return; + } + port->flags |= ASYNC_CLOSING; + + /* + * Now we wait for the transmit buffer to clear; and we notify + * the line discipline to only process XON/XOFF characters. + */ + tty->closing = 1; + /* if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) + tty_wait_until_sent(tty, port->closing_wait); */ + + /* + * At this point we stop accepting input. To do this, we + * disable the receive line status interrupts, and tell the + * interrupt driver to stop checking the data ready bit in the + * line status register. + */ + + port->rd->disable_rx_interrupts (port); + spin_unlock_irqrestore(&port->driver_lock, flags); + + /* close has no way of returning "EINTR", so discard return value */ + if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) + gs_wait_tx_flushed (port, port->closing_wait); + + port->flags &= ~GS_ACTIVE; + + if (tty->driver->flush_buffer) + tty->driver->flush_buffer(tty); + + tty_ldisc_flush(tty); + tty->closing = 0; + + port->event = 0; + port->rd->close (port); + port->rd->shutdown_port (port); + port->tty = NULL; + + if (port->blocked_open) { + if (port->close_delay) { + spin_unlock_irqrestore(&port->driver_lock, flags); + msleep_interruptible(jiffies_to_msecs(port->close_delay)); + spin_lock_irqsave(&port->driver_lock, flags); + } + wake_up_interruptible(&port->open_wait); + } + port->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING | ASYNC_INITIALIZED); + wake_up_interruptible(&port->close_wait); + + func_exit (); +} + + +static unsigned int gs_baudrates[] = { + 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, + 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600 +}; + + +void gs_set_termios (struct tty_struct * tty, + struct termios * old_termios) +{ + struct gs_port *port; + int baudrate, tmp, rv; + struct termios *tiosp; + + func_enter(); + + if (!tty) return; + + port = tty->driver_data; + + if (!port) return; + if (!port->tty) { + /* This seems to happen when this is called after gs_close. */ + gs_dprintk (GS_DEBUG_TERMIOS, "gs: Odd: port->tty is NULL\n"); + port->tty = tty; + } + + + tiosp = tty->termios; + + if (gs_debug & GS_DEBUG_TERMIOS) { + gs_dprintk (GS_DEBUG_TERMIOS, "termios structure (%p):\n", tiosp); + } + +#if 0 + /* This is an optimization that is only allowed for dumb cards */ + /* Smart cards require knowledge of iflags and oflags too: that + might change hardware cooking mode.... */ +#endif + if (old_termios) { + if( (tiosp->c_iflag == old_termios->c_iflag) + && (tiosp->c_oflag == old_termios->c_oflag) + && (tiosp->c_cflag == old_termios->c_cflag) + && (tiosp->c_lflag == old_termios->c_lflag) + && (tiosp->c_line == old_termios->c_line) + && (memcmp(tiosp->c_cc, old_termios->c_cc, NCC) == 0)) { + gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: optimized away\n"); + return /* 0 */; + } + } else + gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: no old_termios: " + "no optimization\n"); + + if(old_termios && (gs_debug & GS_DEBUG_TERMIOS)) { + if(tiosp->c_iflag != old_termios->c_iflag) printk("c_iflag changed\n"); + if(tiosp->c_oflag != old_termios->c_oflag) printk("c_oflag changed\n"); + if(tiosp->c_cflag != old_termios->c_cflag) printk("c_cflag changed\n"); + if(tiosp->c_lflag != old_termios->c_lflag) printk("c_lflag changed\n"); + if(tiosp->c_line != old_termios->c_line) printk("c_line changed\n"); + if(!memcmp(tiosp->c_cc, old_termios->c_cc, NCC)) printk("c_cc changed\n"); + } + + baudrate = tiosp->c_cflag & CBAUD; + if (baudrate & CBAUDEX) { + baudrate &= ~CBAUDEX; + if ((baudrate < 1) || (baudrate > 4)) + tiosp->c_cflag &= ~CBAUDEX; + else + baudrate += 15; + } + + baudrate = gs_baudrates[baudrate]; + if ((tiosp->c_cflag & CBAUD) == B38400) { + if ( (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI) + baudrate = 57600; + else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI) + baudrate = 115200; + else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI) + baudrate = 230400; + else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP) + baudrate = 460800; + else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) + baudrate = (port->baud_base / port->custom_divisor); + } + + /* I recommend using THIS instead of the mess in termios (and + duplicating the above code). Next we should create a clean + interface towards this variable. If your card supports arbitrary + baud rates, (e.g. CD1400 or 16550 based cards) then everything + will be very easy..... */ + port->baud = baudrate; + + /* Two timer ticks seems enough to wakeup something like SLIP driver */ + /* Baudrate/10 is cps. Divide by HZ to get chars per tick. */ + tmp = (baudrate / 10 / HZ) * 2; + + if (tmp < 0) tmp = 0; + if (tmp >= SERIAL_XMIT_SIZE) tmp = SERIAL_XMIT_SIZE-1; + + port->wakeup_chars = tmp; + + /* We should really wait for the characters to be all sent before + changing the settings. -- CAL */ + rv = gs_wait_tx_flushed (port, MAX_SCHEDULE_TIMEOUT); + if (rv < 0) return /* rv */; + + rv = port->rd->set_real_termios(port); + if (rv < 0) return /* rv */; + + if ((!old_termios || + (old_termios->c_cflag & CRTSCTS)) && + !( tiosp->c_cflag & CRTSCTS)) { + tty->stopped = 0; + gs_start(tty); + } + +#ifdef tytso_patch_94Nov25_1726 + /* This "makes sense", Why is it commented out? */ + + if (!(old_termios->c_cflag & CLOCAL) && + (tty->termios->c_cflag & CLOCAL)) + wake_up_interruptible(&port->gs.open_wait); +#endif + + func_exit(); + return /* 0 */; +} + + + +/* Must be called with interrupts enabled */ +int gs_init_port(struct gs_port *port) +{ + unsigned long flags; + unsigned long page; + + func_enter (); + + if (!tmp_buf) { + page = get_zeroed_page(GFP_KERNEL); + spin_lock_irqsave (&port->driver_lock, flags); /* Don't expect this to make a difference. */ + if (tmp_buf) + free_page(page); + else + tmp_buf = (unsigned char *) page; + spin_unlock_irqrestore (&port->driver_lock, flags); + if (!tmp_buf) { + func_exit (); + return -ENOMEM; + } + } + + if (port->flags & ASYNC_INITIALIZED) { + func_exit (); + return 0; + } + if (!port->xmit_buf) { + /* We may sleep in get_zeroed_page() */ + unsigned long tmp; + + tmp = get_zeroed_page(GFP_KERNEL); + spin_lock_irqsave (&port->driver_lock, flags); + if (port->xmit_buf) + free_page (tmp); + else + port->xmit_buf = (unsigned char *) tmp; + spin_unlock_irqrestore(&port->driver_lock, flags); + if (!port->xmit_buf) { + func_exit (); + return -ENOMEM; + } + } + + spin_lock_irqsave (&port->driver_lock, flags); + if (port->tty) + clear_bit(TTY_IO_ERROR, &port->tty->flags); + init_MUTEX(&port->port_write_sem); + port->xmit_cnt = port->xmit_head = port->xmit_tail = 0; + spin_unlock_irqrestore(&port->driver_lock, flags); + gs_set_termios(port->tty, NULL); + spin_lock_irqsave (&port->driver_lock, flags); + port->flags |= ASYNC_INITIALIZED; + port->flags &= ~GS_TX_INTEN; + + spin_unlock_irqrestore(&port->driver_lock, flags); + func_exit (); + return 0; +} + + +int gs_setserial(struct gs_port *port, struct serial_struct __user *sp) +{ + struct serial_struct sio; + + if (copy_from_user(&sio, sp, sizeof(struct serial_struct))) + return(-EFAULT); + + if (!capable(CAP_SYS_ADMIN)) { + if ((sio.baud_base != port->baud_base) || + (sio.close_delay != port->close_delay) || + ((sio.flags & ~ASYNC_USR_MASK) != + (port->flags & ~ASYNC_USR_MASK))) + return(-EPERM); + } + + port->flags = (port->flags & ~ASYNC_USR_MASK) | + (sio.flags & ASYNC_USR_MASK); + + port->baud_base = sio.baud_base; + port->close_delay = sio.close_delay; + port->closing_wait = sio.closing_wait; + port->custom_divisor = sio.custom_divisor; + + gs_set_termios (port->tty, NULL); + + return 0; +} + + +/*****************************************************************************/ + +/* + * Generate the serial struct info. + */ + +int gs_getserial(struct gs_port *port, struct serial_struct __user *sp) +{ + struct serial_struct sio; + + memset(&sio, 0, sizeof(struct serial_struct)); + sio.flags = port->flags; + sio.baud_base = port->baud_base; + sio.close_delay = port->close_delay; + sio.closing_wait = port->closing_wait; + sio.custom_divisor = port->custom_divisor; + sio.hub6 = 0; + + /* If you want you can override these. */ + sio.type = PORT_UNKNOWN; + sio.xmit_fifo_size = -1; + sio.line = -1; + sio.port = -1; + sio.irq = -1; + + if (port->rd->getserial) + port->rd->getserial (port, &sio); + + if (copy_to_user(sp, &sio, sizeof(struct serial_struct))) + return -EFAULT; + return 0; + +} + + +void gs_got_break(struct gs_port *port) +{ + func_enter (); + + tty_insert_flip_char(port->tty, 0, TTY_BREAK); + tty_schedule_flip(port->tty); + if (port->flags & ASYNC_SAK) { + do_SAK (port->tty); + } + + func_exit (); +} + + +EXPORT_SYMBOL(gs_put_char); +EXPORT_SYMBOL(gs_write); +EXPORT_SYMBOL(gs_write_room); +EXPORT_SYMBOL(gs_chars_in_buffer); +EXPORT_SYMBOL(gs_flush_buffer); +EXPORT_SYMBOL(gs_flush_chars); +EXPORT_SYMBOL(gs_stop); +EXPORT_SYMBOL(gs_start); +EXPORT_SYMBOL(gs_hangup); +EXPORT_SYMBOL(gs_block_til_ready); +EXPORT_SYMBOL(gs_close); +EXPORT_SYMBOL(gs_set_termios); +EXPORT_SYMBOL(gs_init_port); +EXPORT_SYMBOL(gs_setserial); +EXPORT_SYMBOL(gs_getserial); +EXPORT_SYMBOL(gs_got_break); + +MODULE_LICENSE("GPL"); |