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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/generic_serial.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/char/generic_serial.c')
-rw-r--r--drivers/char/generic_serial.c1001
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 000000000000..204a7302a4a9
--- /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*)(&current->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");