--- /dev/null
+/*
+ * Copyright 2003 Digi International (www.digi.com)
+ * Scott H Kilau <Scott_Kilau at digi dot com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
+ * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE. See the GNU General Public License for more details.
+ */
+
+/************************************************************************
+ *
+ * This file implements the tty driver functionality for the
+ * Neo and ClassicBoard PCI based product lines.
+ *
+ ************************************************************************
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h> /* For jiffies, task states */
+#include <linux/interrupt.h> /* For tasklet and interrupt structs/defines */
+#include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/types.h>
+#include <linux/serial_reg.h>
+#include <linux/slab.h>
+#include <linux/delay.h> /* For udelay */
+#include <linux/uaccess.h> /* For copy_from_user/copy_to_user */
+#include <linux/pci.h>
+#include "dgnc_driver.h"
+#include "dgnc_tty.h"
+#include "dgnc_neo.h"
+#include "dgnc_cls.h"
+#include "dgnc_sysfs.h"
+#include "dgnc_utils.h"
+
+#define init_MUTEX(sem) sema_init(sem, 1)
+#define DECLARE_MUTEX(name) \
+ struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1)
+
+/*
+ * internal variables
+ */
+static struct dgnc_board *dgnc_BoardsByMajor[256];
+static unsigned char *dgnc_TmpWriteBuf;
+static DECLARE_MUTEX(dgnc_TmpWriteSem);
+
+/*
+ * Default transparent print information.
+ */
+static struct digi_t dgnc_digi_init = {
+ .digi_flags = DIGI_COOK, /* Flags */
+ .digi_maxcps = 100, /* Max CPS */
+ .digi_maxchar = 50, /* Max chars in print queue */
+ .digi_bufsize = 100, /* Printer buffer size */
+ .digi_onlen = 4, /* size of printer on string */
+ .digi_offlen = 4, /* size of printer off string */
+ .digi_onstr = "\033[5i", /* ANSI printer on string ] */
+ .digi_offstr = "\033[4i", /* ANSI printer off string ] */
+ .digi_term = "ansi" /* default terminal type */
+};
+
+
+/*
+ * Define a local default termios struct. All ports will be created
+ * with this termios initially.
+ *
+ * This defines a raw port at 9600 baud, 8 data bits, no parity,
+ * 1 stop bit.
+ */
+static struct ktermios DgncDefaultTermios = {
+ .c_iflag = (DEFAULT_IFLAGS), /* iflags */
+ .c_oflag = (DEFAULT_OFLAGS), /* oflags */
+ .c_cflag = (DEFAULT_CFLAGS), /* cflags */
+ .c_lflag = (DEFAULT_LFLAGS), /* lflags */
+ .c_cc = INIT_C_CC,
+ .c_line = 0,
+};
+
+
+/* Our function prototypes */
+static int dgnc_tty_open(struct tty_struct *tty, struct file *file);
+static void dgnc_tty_close(struct tty_struct *tty, struct file *file);
+static int dgnc_block_til_ready(struct tty_struct *tty, struct file *file, struct channel_t *ch);
+static int dgnc_tty_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg);
+static int dgnc_tty_digigeta(struct tty_struct *tty, struct digi_t __user *retinfo);
+static int dgnc_tty_digiseta(struct tty_struct *tty, struct digi_t __user *new_info);
+static int dgnc_tty_write_room(struct tty_struct *tty);
+static int dgnc_tty_put_char(struct tty_struct *tty, unsigned char c);
+static int dgnc_tty_chars_in_buffer(struct tty_struct *tty);
+static void dgnc_tty_start(struct tty_struct *tty);
+static void dgnc_tty_stop(struct tty_struct *tty);
+static void dgnc_tty_throttle(struct tty_struct *tty);
+static void dgnc_tty_unthrottle(struct tty_struct *tty);
+static void dgnc_tty_flush_chars(struct tty_struct *tty);
+static void dgnc_tty_flush_buffer(struct tty_struct *tty);
+static void dgnc_tty_hangup(struct tty_struct *tty);
+static int dgnc_set_modem_info(struct tty_struct *tty, unsigned int command, unsigned int __user *value);
+static int dgnc_get_modem_info(struct channel_t *ch, unsigned int __user *value);
+static int dgnc_tty_tiocmget(struct tty_struct *tty);
+static int dgnc_tty_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear);
+static int dgnc_tty_send_break(struct tty_struct *tty, int msec);
+static void dgnc_tty_wait_until_sent(struct tty_struct *tty, int timeout);
+static int dgnc_tty_write(struct tty_struct *tty, const unsigned char *buf, int count);
+static void dgnc_tty_set_termios(struct tty_struct *tty, struct ktermios *old_termios);
+static void dgnc_tty_send_xchar(struct tty_struct *tty, char ch);
+
+
+static const struct tty_operations dgnc_tty_ops = {
+ .open = dgnc_tty_open,
+ .close = dgnc_tty_close,
+ .write = dgnc_tty_write,
+ .write_room = dgnc_tty_write_room,
+ .flush_buffer = dgnc_tty_flush_buffer,
+ .chars_in_buffer = dgnc_tty_chars_in_buffer,
+ .flush_chars = dgnc_tty_flush_chars,
+ .ioctl = dgnc_tty_ioctl,
+ .set_termios = dgnc_tty_set_termios,
+ .stop = dgnc_tty_stop,
+ .start = dgnc_tty_start,
+ .throttle = dgnc_tty_throttle,
+ .unthrottle = dgnc_tty_unthrottle,
+ .hangup = dgnc_tty_hangup,
+ .put_char = dgnc_tty_put_char,
+ .tiocmget = dgnc_tty_tiocmget,
+ .tiocmset = dgnc_tty_tiocmset,
+ .break_ctl = dgnc_tty_send_break,
+ .wait_until_sent = dgnc_tty_wait_until_sent,
+ .send_xchar = dgnc_tty_send_xchar
+};
+
+/************************************************************************
+ *
+ * TTY Initialization/Cleanup Functions
+ *
+ ************************************************************************/
+
+/*
+ * dgnc_tty_preinit()
+ *
+ * Initialize any global tty related data before we download any boards.
+ */
+int dgnc_tty_preinit(void)
+{
+ /*
+ * Allocate a buffer for doing the copy from user space to
+ * kernel space in dgnc_write(). We only use one buffer and
+ * control access to it with a semaphore. If we are paging, we
+ * are already in trouble so one buffer won't hurt much anyway.
+ *
+ * We are okay to sleep in the malloc, as this routine
+ * is only called during module load, (not in interrupt context),
+ * and with no locks held.
+ */
+ dgnc_TmpWriteBuf = kmalloc(WRITEBUFLEN, GFP_KERNEL);
+
+ if (!dgnc_TmpWriteBuf)
+ return -ENOMEM;
+
+ return 0;
+}
+
+
+/*
+ * dgnc_tty_register()
+ *
+ * Init the tty subsystem for this board.
+ */
+int dgnc_tty_register(struct dgnc_board *brd)
+{
+ int rc = 0;
+
+ brd->SerialDriver.magic = TTY_DRIVER_MAGIC;
+
+ snprintf(brd->SerialName, MAXTTYNAMELEN, "tty_dgnc_%d_", brd->boardnum);
+
+ brd->SerialDriver.name = brd->SerialName;
+ brd->SerialDriver.name_base = 0;
+ brd->SerialDriver.major = 0;
+ brd->SerialDriver.minor_start = 0;
+ brd->SerialDriver.num = brd->maxports;
+ brd->SerialDriver.type = TTY_DRIVER_TYPE_SERIAL;
+ brd->SerialDriver.subtype = SERIAL_TYPE_NORMAL;
+ brd->SerialDriver.init_termios = DgncDefaultTermios;
+ brd->SerialDriver.driver_name = DRVSTR;
+ brd->SerialDriver.flags = (TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_HARDWARE_BREAK);
+
+ /*
+ * The kernel wants space to store pointers to
+ * tty_struct's and termios's.
+ */
+ brd->SerialDriver.ttys = kcalloc(brd->maxports, sizeof(*brd->SerialDriver.ttys), GFP_KERNEL);
+ if (!brd->SerialDriver.ttys)
+ return -ENOMEM;
+
+ kref_init(&brd->SerialDriver.kref);
+ brd->SerialDriver.termios = kcalloc(brd->maxports, sizeof(*brd->SerialDriver.termios), GFP_KERNEL);
+ if (!brd->SerialDriver.termios)
+ return -ENOMEM;
+
+ /*
+ * Entry points for driver. Called by the kernel from
+ * tty_io.c and n_tty.c.
+ */
+ tty_set_operations(&brd->SerialDriver, &dgnc_tty_ops);
+
+ if (!brd->dgnc_Major_Serial_Registered) {
+ /* Register tty devices */
+ rc = tty_register_driver(&brd->SerialDriver);
+ if (rc < 0) {
+ dev_dbg(&brd->pdev->dev,
+ "Can't register tty device (%d)\n", rc);
+ return rc;
+ }
+ brd->dgnc_Major_Serial_Registered = true;
+ }
+
+ /*
+ * If we're doing transparent print, we have to do all of the above
+ * again, separately so we don't get the LD confused about what major
+ * we are when we get into the dgnc_tty_open() routine.
+ */
+ brd->PrintDriver.magic = TTY_DRIVER_MAGIC;
+ snprintf(brd->PrintName, MAXTTYNAMELEN, "pr_dgnc_%d_", brd->boardnum);
+
+ brd->PrintDriver.name = brd->PrintName;
+ brd->PrintDriver.name_base = 0;
+ brd->PrintDriver.major = brd->SerialDriver.major;
+ brd->PrintDriver.minor_start = 0x80;
+ brd->PrintDriver.num = brd->maxports;
+ brd->PrintDriver.type = TTY_DRIVER_TYPE_SERIAL;
+ brd->PrintDriver.subtype = SERIAL_TYPE_NORMAL;
+ brd->PrintDriver.init_termios = DgncDefaultTermios;
+ brd->PrintDriver.driver_name = DRVSTR;
+ brd->PrintDriver.flags = (TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_HARDWARE_BREAK);
+
+ /*
+ * The kernel wants space to store pointers to
+ * tty_struct's and termios's. Must be separated from
+ * the Serial Driver so we don't get confused
+ */
+ brd->PrintDriver.ttys = kcalloc(brd->maxports, sizeof(*brd->PrintDriver.ttys), GFP_KERNEL);
+ if (!brd->PrintDriver.ttys)
+ return -ENOMEM;
+ kref_init(&brd->PrintDriver.kref);
+ brd->PrintDriver.termios = kcalloc(brd->maxports, sizeof(*brd->PrintDriver.termios), GFP_KERNEL);
+ if (!brd->PrintDriver.termios)
+ return -ENOMEM;
+
+ /*
+ * Entry points for driver. Called by the kernel from
+ * tty_io.c and n_tty.c.
+ */
+ tty_set_operations(&brd->PrintDriver, &dgnc_tty_ops);
+
+ if (!brd->dgnc_Major_TransparentPrint_Registered) {
+ /* Register Transparent Print devices */
+ rc = tty_register_driver(&brd->PrintDriver);
+ if (rc < 0) {
+ dev_dbg(&brd->pdev->dev,
+ "Can't register Transparent Print device(%d)\n",
+ rc);
+ return rc;
+ }
+ brd->dgnc_Major_TransparentPrint_Registered = true;
+ }
+
+ dgnc_BoardsByMajor[brd->SerialDriver.major] = brd;
+ brd->dgnc_Serial_Major = brd->SerialDriver.major;
+ brd->dgnc_TransparentPrint_Major = brd->PrintDriver.major;
+
+ return rc;
+}
+
+
+/*
+ * dgnc_tty_init()
+ *
+ * Init the tty subsystem. Called once per board after board has been
+ * downloaded and init'ed.
+ */
+int dgnc_tty_init(struct dgnc_board *brd)
+{
+ int i;
+ void __iomem *vaddr;
+ struct channel_t *ch;
+
+ if (!brd)
+ return -ENXIO;
+
+ /*
+ * Initialize board structure elements.
+ */
+
+ vaddr = brd->re_map_membase;
+
+ brd->nasync = brd->maxports;
+
+ /*
+ * Allocate channel memory that might not have been allocated
+ * when the driver was first loaded.
+ */
+ for (i = 0; i < brd->nasync; i++) {
+ if (!brd->channels[i]) {
+
+ /*
+ * Okay to malloc with GFP_KERNEL, we are not at
+ * interrupt context, and there are no locks held.
+ */
+ brd->channels[i] = kzalloc(sizeof(*brd->channels[i]), GFP_KERNEL);
+ }
+ }
+
+ ch = brd->channels[0];
+ vaddr = brd->re_map_membase;
+
+ /* Set up channel variables */
+ for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
+
+ if (!brd->channels[i])
+ continue;
+
+ spin_lock_init(&ch->ch_lock);
+
+ /* Store all our magic numbers */
+ ch->magic = DGNC_CHANNEL_MAGIC;
+ ch->ch_tun.magic = DGNC_UNIT_MAGIC;
+ ch->ch_tun.un_ch = ch;
+ ch->ch_tun.un_type = DGNC_SERIAL;
+ ch->ch_tun.un_dev = i;
+
+ ch->ch_pun.magic = DGNC_UNIT_MAGIC;
+ ch->ch_pun.un_ch = ch;
+ ch->ch_pun.un_type = DGNC_PRINT;
+ ch->ch_pun.un_dev = i + 128;
+
+ if (brd->bd_uart_offset == 0x200)
+ ch->ch_neo_uart = vaddr + (brd->bd_uart_offset * i);
+ else
+ ch->ch_cls_uart = vaddr + (brd->bd_uart_offset * i);
+
+ ch->ch_bd = brd;
+ ch->ch_portnum = i;
+ ch->ch_digi = dgnc_digi_init;
+
+ /* .25 second delay */
+ ch->ch_close_delay = 250;
+
+ init_waitqueue_head(&ch->ch_flags_wait);
+ init_waitqueue_head(&ch->ch_tun.un_flags_wait);
+ init_waitqueue_head(&ch->ch_pun.un_flags_wait);
+
+ {
+ struct device *classp;
+
+ classp = tty_register_device(&brd->SerialDriver, i,
+ &(ch->ch_bd->pdev->dev));
+ ch->ch_tun.un_sysfs = classp;
+ dgnc_create_tty_sysfs(&ch->ch_tun, classp);
+
+ classp = tty_register_device(&brd->PrintDriver, i,
+ &(ch->ch_bd->pdev->dev));
+ ch->ch_pun.un_sysfs = classp;
+ dgnc_create_tty_sysfs(&ch->ch_pun, classp);
+ }
+
+ }
+
+ return 0;
+}
+
+
+/*
+ * dgnc_tty_post_uninit()
+ *
+ * UnInitialize any global tty related data.
+ */
+void dgnc_tty_post_uninit(void)
+{
+ kfree(dgnc_TmpWriteBuf);
+ dgnc_TmpWriteBuf = NULL;
+}
+
+
+/*
+ * dgnc_tty_uninit()
+ *
+ * Uninitialize the TTY portion of this driver. Free all memory and
+ * resources.
+ */
+void dgnc_tty_uninit(struct dgnc_board *brd)
+{
+ int i = 0;
+
+ if (brd->dgnc_Major_Serial_Registered) {
+ dgnc_BoardsByMajor[brd->SerialDriver.major] = NULL;
+ brd->dgnc_Serial_Major = 0;
+ for (i = 0; i < brd->nasync; i++) {
+ dgnc_remove_tty_sysfs(brd->channels[i]->ch_tun.un_sysfs);
+ tty_unregister_device(&brd->SerialDriver, i);
+ }
+ tty_unregister_driver(&brd->SerialDriver);
+ brd->dgnc_Major_Serial_Registered = false;
+ }
+
+ if (brd->dgnc_Major_TransparentPrint_Registered) {
+ dgnc_BoardsByMajor[brd->PrintDriver.major] = NULL;
+ brd->dgnc_TransparentPrint_Major = 0;
+ for (i = 0; i < brd->nasync; i++) {
+ dgnc_remove_tty_sysfs(brd->channels[i]->ch_pun.un_sysfs);
+ tty_unregister_device(&brd->PrintDriver, i);
+ }
+ tty_unregister_driver(&brd->PrintDriver);
+ brd->dgnc_Major_TransparentPrint_Registered = false;
+ }
+
+ kfree(brd->SerialDriver.ttys);
+ brd->SerialDriver.ttys = NULL;
+ kfree(brd->PrintDriver.ttys);
+ brd->PrintDriver.ttys = NULL;
+}
+
+
+#define TMPBUFLEN (1024)
+
+/*=======================================================================
+ *
+ * dgnc_wmove - Write data to transmit queue.
+ *
+ * ch - Pointer to channel structure.
+ * buf - Poiter to characters to be moved.
+ * n - Number of characters to move.
+ *
+ *=======================================================================*/
+static void dgnc_wmove(struct channel_t *ch, char *buf, uint n)
+{
+ int remain;
+ uint head;
+
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ head = ch->ch_w_head & WQUEUEMASK;
+
+ /*
+ * If the write wraps over the top of the circular buffer,
+ * move the portion up to the wrap point, and reset the
+ * pointers to the bottom.
+ */
+ remain = WQUEUESIZE - head;
+
+ if (n >= remain) {
+ n -= remain;
+ memcpy(ch->ch_wqueue + head, buf, remain);
+ head = 0;
+ buf += remain;
+ }
+
+ if (n > 0) {
+ /*
+ * Move rest of data.
+ */
+ remain = n;
+ memcpy(ch->ch_wqueue + head, buf, remain);
+ head += remain;
+ }
+
+ head &= WQUEUEMASK;
+ ch->ch_w_head = head;
+}
+
+
+
+
+/*=======================================================================
+ *
+ * dgnc_input - Process received data.
+ *
+ * ch - Pointer to channel structure.
+ *
+ *=======================================================================*/
+void dgnc_input(struct channel_t *ch)
+{
+ struct dgnc_board *bd;
+ struct tty_struct *tp;
+ struct tty_ldisc *ld = NULL;
+ uint rmask;
+ ushort head;
+ ushort tail;
+ int data_len;
+ unsigned long flags;
+ int flip_len;
+ int len = 0;
+ int n = 0;
+ int s = 0;
+ int i = 0;
+
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ tp = ch->ch_tun.un_tty;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ /*
+ * Figure the number of characters in the buffer.
+ * Exit immediately if none.
+ */
+ rmask = RQUEUEMASK;
+ head = ch->ch_r_head & rmask;
+ tail = ch->ch_r_tail & rmask;
+ data_len = (head - tail) & rmask;
+
+ if (data_len == 0)
+ goto exit_unlock;
+
+ /*
+ * If the device is not open, or CREAD is off,
+ * flush input data and return immediately.
+ */
+ if (!tp || (tp->magic != TTY_MAGIC) || !(ch->ch_tun.un_flags & UN_ISOPEN) ||
+ !(tp->termios.c_cflag & CREAD) || (ch->ch_tun.un_flags & UN_CLOSING)) {
+
+ ch->ch_r_head = tail;
+
+ /* Force queue flow control to be released, if needed */
+ dgnc_check_queue_flow_control(ch);
+
+ goto exit_unlock;
+ }
+
+ /*
+ * If we are throttled, simply don't read any data.
+ */
+ if (ch->ch_flags & CH_FORCED_STOPI)
+ goto exit_unlock;
+
+ flip_len = TTY_FLIPBUF_SIZE;
+
+ /* Chop down the length, if needed */
+ len = min(data_len, flip_len);
+ len = min(len, (N_TTY_BUF_SIZE - 1));
+
+ ld = tty_ldisc_ref(tp);
+
+#ifdef TTY_DONT_FLIP
+ /*
+ * If the DONT_FLIP flag is on, don't flush our buffer, and act
+ * like the ld doesn't have any space to put the data right now.
+ */
+ if (test_bit(TTY_DONT_FLIP, &tp->flags))
+ len = 0;
+#endif
+
+ /*
+ * If we were unable to get a reference to the ld,
+ * don't flush our buffer, and act like the ld doesn't
+ * have any space to put the data right now.
+ */
+ if (!ld) {
+ len = 0;
+ } else {
+ /*
+ * If ld doesn't have a pointer to a receive_buf function,
+ * flush the data, then act like the ld doesn't have any
+ * space to put the data right now.
+ */
+ if (!ld->ops->receive_buf) {
+ ch->ch_r_head = ch->ch_r_tail;
+ len = 0;
+ }
+ }
+
+ if (len <= 0)
+ goto exit_unlock;
+
+ /*
+ * The tty layer in the kernel has changed in 2.6.16+.
+ *
+ * The flip buffers in the tty structure are no longer exposed,
+ * and probably will be going away eventually.
+ *
+ * If we are completely raw, we don't need to go through a lot
+ * of the tty layers that exist.
+ * In this case, we take the shortest and fastest route we
+ * can to relay the data to the user.
+ *
+ * On the other hand, if we are not raw, we need to go through
+ * the new 2.6.16+ tty layer, which has its API more well defined.
+ */
+ len = tty_buffer_request_room(tp->port, len);
+ n = len;
+
+ /*
+ * n now contains the most amount of data we can copy,
+ * bounded either by how much the Linux tty layer can handle,
+ * or the amount of data the card actually has pending...
+ */
+ while (n) {
+ s = ((head >= tail) ? head : RQUEUESIZE) - tail;
+ s = min(s, n);
+
+ if (s <= 0)
+ break;
+
+ /*
+ * If conditions are such that ld needs to see all
+ * UART errors, we will have to walk each character
+ * and error byte and send them to the buffer one at
+ * a time.
+ */
+ if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
+ for (i = 0; i < s; i++) {
+ if (*(ch->ch_equeue + tail + i) & UART_LSR_BI)
+ tty_insert_flip_char(tp->port, *(ch->ch_rqueue + tail + i), TTY_BREAK);
+ else if (*(ch->ch_equeue + tail + i) & UART_LSR_PE)
+ tty_insert_flip_char(tp->port, *(ch->ch_rqueue + tail + i), TTY_PARITY);
+ else if (*(ch->ch_equeue + tail + i) & UART_LSR_FE)
+ tty_insert_flip_char(tp->port, *(ch->ch_rqueue + tail + i), TTY_FRAME);
+ else
+ tty_insert_flip_char(tp->port, *(ch->ch_rqueue + tail + i), TTY_NORMAL);
+ }
+ } else {
+ tty_insert_flip_string(tp->port, ch->ch_rqueue + tail, s);
+ }
+
+ tail += s;
+ n -= s;
+ /* Flip queue if needed */
+ tail &= rmask;
+ }
+
+ ch->ch_r_tail = tail & rmask;
+ ch->ch_e_tail = tail & rmask;
+ dgnc_check_queue_flow_control(ch);
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ /* Tell the tty layer its okay to "eat" the data now */
+ tty_flip_buffer_push(tp->port);
+
+ if (ld)
+ tty_ldisc_deref(ld);
+ return;
+
+exit_unlock:
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ if (ld)
+ tty_ldisc_deref(ld);
+}
+
+
+/************************************************************************
+ * Determines when CARRIER changes state and takes appropriate
+ * action.
+ ************************************************************************/
+void dgnc_carrier(struct channel_t *ch)
+{
+ struct dgnc_board *bd;
+
+ int virt_carrier = 0;
+ int phys_carrier = 0;
+
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ bd = ch->ch_bd;
+
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return;
+
+ if (ch->ch_mistat & UART_MSR_DCD)
+ phys_carrier = 1;
+
+ if (ch->ch_digi.digi_flags & DIGI_FORCEDCD)
+ virt_carrier = 1;
+
+ if (ch->ch_c_cflag & CLOCAL)
+ virt_carrier = 1;
+
+ /*
+ * Test for a VIRTUAL carrier transition to HIGH.
+ */
+ if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
+
+ /*
+ * When carrier rises, wake any threads waiting
+ * for carrier in the open routine.
+ */
+
+ if (waitqueue_active(&(ch->ch_flags_wait)))
+ wake_up_interruptible(&ch->ch_flags_wait);
+ }
+
+ /*
+ * Test for a PHYSICAL carrier transition to HIGH.
+ */
+ if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
+
+ /*
+ * When carrier rises, wake any threads waiting
+ * for carrier in the open routine.
+ */
+
+ if (waitqueue_active(&(ch->ch_flags_wait)))
+ wake_up_interruptible(&ch->ch_flags_wait);
+ }
+
+ /*
+ * Test for a PHYSICAL transition to low, so long as we aren't
+ * currently ignoring physical transitions (which is what "virtual
+ * carrier" indicates).
+ *
+ * The transition of the virtual carrier to low really doesn't
+ * matter... it really only means "ignore carrier state", not
+ * "make pretend that carrier is there".
+ */
+ if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0) &&
+ (phys_carrier == 0)) {
+
+ /*
+ * When carrier drops:
+ *
+ * Drop carrier on all open units.
+ *
+ * Flush queues, waking up any task waiting in the
+ * line discipline.
+ *
+ * Send a hangup to the control terminal.
+ *
+ * Enable all select calls.
+ */
+ if (waitqueue_active(&(ch->ch_flags_wait)))
+ wake_up_interruptible(&ch->ch_flags_wait);
+
+ if (ch->ch_tun.un_open_count > 0)
+ tty_hangup(ch->ch_tun.un_tty);
+
+ if (ch->ch_pun.un_open_count > 0)
+ tty_hangup(ch->ch_pun.un_tty);
+ }
+
+ /*
+ * Make sure that our cached values reflect the current reality.
+ */
+ if (virt_carrier == 1)
+ ch->ch_flags |= CH_FCAR;
+ else
+ ch->ch_flags &= ~CH_FCAR;
+
+ if (phys_carrier == 1)
+ ch->ch_flags |= CH_CD;
+ else
+ ch->ch_flags &= ~CH_CD;
+}
+
+/*
+ * Assign the custom baud rate to the channel structure
+ */
+static void dgnc_set_custom_speed(struct channel_t *ch, uint newrate)
+{
+ int testdiv;
+ int testrate_high;
+ int testrate_low;
+ int deltahigh;
+ int deltalow;
+
+ if (newrate <= 0) {
+ ch->ch_custom_speed = 0;
+ return;
+ }
+
+ /*
+ * Since the divisor is stored in a 16-bit integer, we make sure
+ * we don't allow any rates smaller than a 16-bit integer would allow.
+ * And of course, rates above the dividend won't fly.
+ */
+ if (newrate && newrate < ((ch->ch_bd->bd_dividend / 0xFFFF) + 1))
+ newrate = ((ch->ch_bd->bd_dividend / 0xFFFF) + 1);
+
+ if (newrate && newrate > ch->ch_bd->bd_dividend)
+ newrate = ch->ch_bd->bd_dividend;
+
+ if (newrate > 0) {
+ testdiv = ch->ch_bd->bd_dividend / newrate;
+
+ /*
+ * If we try to figure out what rate the board would use
+ * with the test divisor, it will be either equal or higher
+ * than the requested baud rate. If we then determine the
+ * rate with a divisor one higher, we will get the next lower
+ * supported rate below the requested.
+ */
+ testrate_high = ch->ch_bd->bd_dividend / testdiv;
+ testrate_low = ch->ch_bd->bd_dividend / (testdiv + 1);
+
+ /*
+ * If the rate for the requested divisor is correct, just
+ * use it and be done.
+ */
+ if (testrate_high != newrate) {
+ /*
+ * Otherwise, pick the rate that is closer (i.e. whichever rate
+ * has a smaller delta).
+ */
+ deltahigh = testrate_high - newrate;
+ deltalow = newrate - testrate_low;
+
+ if (deltahigh < deltalow)
+ newrate = testrate_high;
+ else
+ newrate = testrate_low;
+ }
+ }
+
+ ch->ch_custom_speed = newrate;
+}
+
+
+void dgnc_check_queue_flow_control(struct channel_t *ch)
+{
+ int qleft = 0;
+
+ /* Store how much space we have left in the queue */
+ qleft = ch->ch_r_tail - ch->ch_r_head - 1;
+ if (qleft < 0)
+ qleft += RQUEUEMASK + 1;
+
+ /*
+ * Check to see if we should enforce flow control on our queue because
+ * the ld (or user) isn't reading data out of our queue fast enuf.
+ *
+ * NOTE: This is done based on what the current flow control of the
+ * port is set for.
+ *
+ * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
+ * This will cause the UART's FIFO to back up, and force
+ * the RTS signal to be dropped.
+ * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
+ * the other side, in hopes it will stop sending data to us.
+ * 3) NONE - Nothing we can do. We will simply drop any extra data
+ * that gets sent into us when the queue fills up.
+ */
+ if (qleft < 256) {
+ /* HWFLOW */
+ if (ch->ch_digi.digi_flags & CTSPACE || ch->ch_c_cflag & CRTSCTS) {
+ if (!(ch->ch_flags & CH_RECEIVER_OFF)) {
+ ch->ch_bd->bd_ops->disable_receiver(ch);
+ ch->ch_flags |= (CH_RECEIVER_OFF);
+ }
+ }
+ /* SWFLOW */
+ else if (ch->ch_c_iflag & IXOFF) {
+ if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
+ ch->ch_bd->bd_ops->send_stop_character(ch);
+ ch->ch_stops_sent++;
+ }
+ }
+ }
+
+ /*
+ * Check to see if we should unenforce flow control because
+ * ld (or user) finally read enuf data out of our queue.
+ *
+ * NOTE: This is done based on what the current flow control of the
+ * port is set for.
+ *
+ * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
+ * This will cause the UART's FIFO to raise RTS back up,
+ * which will allow the other side to start sending data again.
+ * 2) SWFLOW (IXOFF) - Send a start character to
+ * the other side, so it will start sending data to us again.
+ * 3) NONE - Do nothing. Since we didn't do anything to turn off the
+ * other side, we don't need to do anything now.
+ */
+ if (qleft > (RQUEUESIZE / 2)) {
+ /* HWFLOW */
+ if (ch->ch_digi.digi_flags & RTSPACE || ch->ch_c_cflag & CRTSCTS) {
+ if (ch->ch_flags & CH_RECEIVER_OFF) {
+ ch->ch_bd->bd_ops->enable_receiver(ch);
+ ch->ch_flags &= ~(CH_RECEIVER_OFF);
+ }
+ }
+ /* SWFLOW */
+ else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
+ ch->ch_stops_sent = 0;
+ ch->ch_bd->bd_ops->send_start_character(ch);
+ }
+ /* No FLOW */
+ else {
+ /* Nothing needed. */
+ }
+ }
+}
+
+
+void dgnc_wakeup_writes(struct channel_t *ch)
+{
+ int qlen = 0;
+ unsigned long flags;
+
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ /*
+ * If channel now has space, wake up anyone waiting on the condition.
+ */
+ qlen = ch->ch_w_head - ch->ch_w_tail;
+ if (qlen < 0)
+ qlen += WQUEUESIZE;
+
+ if (qlen >= (WQUEUESIZE - 256)) {
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return;
+ }
+
+ if (ch->ch_tun.un_flags & UN_ISOPEN) {
+ if ((ch->ch_tun.un_tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
+ ch->ch_tun.un_tty->ldisc->ops->write_wakeup) {
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ (ch->ch_tun.un_tty->ldisc->ops->write_wakeup)(ch->ch_tun.un_tty);
+ spin_lock_irqsave(&ch->ch_lock, flags);
+ }
+
+ wake_up_interruptible(&ch->ch_tun.un_tty->write_wait);
+
+ /*
+ * If unit is set to wait until empty, check to make sure
+ * the queue AND FIFO are both empty.
+ */
+ if (ch->ch_tun.un_flags & UN_EMPTY) {
+ if ((qlen == 0) && (ch->ch_bd->bd_ops->get_uart_bytes_left(ch) == 0)) {
+ ch->ch_tun.un_flags &= ~(UN_EMPTY);
+
+ /*
+ * If RTS Toggle mode is on, whenever
+ * the queue and UART is empty, keep RTS low.
+ */
+ if (ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE) {
+ ch->ch_mostat &= ~(UART_MCR_RTS);
+ ch->ch_bd->bd_ops->assert_modem_signals(ch);
+ }
+
+ /*
+ * If DTR Toggle mode is on, whenever
+ * the queue and UART is empty, keep DTR low.
+ */
+ if (ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE) {
+ ch->ch_mostat &= ~(UART_MCR_DTR);
+ ch->ch_bd->bd_ops->assert_modem_signals(ch);
+ }
+ }
+ }
+
+ wake_up_interruptible(&ch->ch_tun.un_flags_wait);
+ }
+
+ if (ch->ch_pun.un_flags & UN_ISOPEN) {
+ if ((ch->ch_pun.un_tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
+ ch->ch_pun.un_tty->ldisc->ops->write_wakeup) {
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ (ch->ch_pun.un_tty->ldisc->ops->write_wakeup)(ch->ch_pun.un_tty);
+ spin_lock_irqsave(&ch->ch_lock, flags);
+ }
+
+ wake_up_interruptible(&ch->ch_pun.un_tty->write_wait);
+
+ /*
+ * If unit is set to wait until empty, check to make sure
+ * the queue AND FIFO are both empty.
+ */
+ if (ch->ch_pun.un_flags & UN_EMPTY) {
+ if ((qlen == 0) && (ch->ch_bd->bd_ops->get_uart_bytes_left(ch) == 0))
+ ch->ch_pun.un_flags &= ~(UN_EMPTY);
+ }
+
+ wake_up_interruptible(&ch->ch_pun.un_flags_wait);
+ }
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+}
+
+
+
+/************************************************************************
+ *
+ * TTY Entry points and helper functions
+ *
+ ************************************************************************/
+
+/*
+ * dgnc_tty_open()
+ *
+ */
+static int dgnc_tty_open(struct tty_struct *tty, struct file *file)
+{
+ struct dgnc_board *brd;
+ struct channel_t *ch;
+ struct un_t *un;
+ uint major = 0;
+ uint minor = 0;
+ int rc = 0;
+ unsigned long flags;
+
+ rc = 0;
+
+ major = MAJOR(tty_devnum(tty));
+ minor = MINOR(tty_devnum(tty));
+
+ if (major > 255)
+ return -ENXIO;
+
+ /* Get board pointer from our array of majors we have allocated */
+ brd = dgnc_BoardsByMajor[major];
+ if (!brd)
+ return -ENXIO;
+
+ /*
+ * If board is not yet up to a state of READY, go to
+ * sleep waiting for it to happen or they cancel the open.
+ */
+ rc = wait_event_interruptible(brd->state_wait,
+ (brd->state & BOARD_READY));
+
+ if (rc)
+ return rc;
+
+ spin_lock_irqsave(&brd->bd_lock, flags);
+
+ /* If opened device is greater than our number of ports, bail. */
+ if (PORT_NUM(minor) >= brd->nasync) {
+ spin_unlock_irqrestore(&brd->bd_lock, flags);
+ return -ENXIO;
+ }
+
+ ch = brd->channels[PORT_NUM(minor)];
+ if (!ch) {
+ spin_unlock_irqrestore(&brd->bd_lock, flags);
+ return -ENXIO;
+ }
+
+ /* Drop board lock */
+ spin_unlock_irqrestore(&brd->bd_lock, flags);
+
+ /* Grab channel lock */
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ /* Figure out our type */
+ if (!IS_PRINT(minor)) {
+ un = &brd->channels[PORT_NUM(minor)]->ch_tun;
+ un->un_type = DGNC_SERIAL;
+ } else if (IS_PRINT(minor)) {
+ un = &brd->channels[PORT_NUM(minor)]->ch_pun;
+ un->un_type = DGNC_PRINT;
+ } else {
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return -ENXIO;
+ }
+
+ /*
+ * If the port is still in a previous open, and in a state
+ * where we simply cannot safely keep going, wait until the
+ * state clears.
+ */
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ rc = wait_event_interruptible(ch->ch_flags_wait, ((ch->ch_flags & CH_OPENING) == 0));
+
+ /* If ret is non-zero, user ctrl-c'ed us */
+ if (rc)
+ return -EINTR;
+
+ /*
+ * If either unit is in the middle of the fragile part of close,
+ * we just cannot touch the channel safely.
+ * Go to sleep, knowing that when the channel can be
+ * touched safely, the close routine will signal the
+ * ch_flags_wait to wake us back up.
+ */
+ rc = wait_event_interruptible(ch->ch_flags_wait,
+ (((ch->ch_tun.un_flags | ch->ch_pun.un_flags) & UN_CLOSING) == 0));
+
+ /* If ret is non-zero, user ctrl-c'ed us */
+ if (rc)
+ return -EINTR;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+
+ /* Store our unit into driver_data, so we always have it available. */
+ tty->driver_data = un;
+
+
+ /*
+ * Initialize tty's
+ */
+ if (!(un->un_flags & UN_ISOPEN)) {
+ /* Store important variables. */
+ un->un_tty = tty;
+
+ /* Maybe do something here to the TTY struct as well? */
+ }
+
+
+ /*
+ * Allocate channel buffers for read/write/error.
+ * Set flag, so we don't get trounced on.
+ */
+ ch->ch_flags |= (CH_OPENING);
+
+ /* Drop locks, as malloc with GFP_KERNEL can sleep */
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ if (!ch->ch_rqueue)
+ ch->ch_rqueue = kzalloc(RQUEUESIZE, GFP_KERNEL);
+ if (!ch->ch_equeue)
+ ch->ch_equeue = kzalloc(EQUEUESIZE, GFP_KERNEL);
+ if (!ch->ch_wqueue)
+ ch->ch_wqueue = kzalloc(WQUEUESIZE, GFP_KERNEL);
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_flags &= ~(CH_OPENING);
+ wake_up_interruptible(&ch->ch_flags_wait);
+
+ /*
+ * Initialize if neither terminal or printer is open.
+ */
+ if (!((ch->ch_tun.un_flags | ch->ch_pun.un_flags) & UN_ISOPEN)) {
+
+ /*
+ * Flush input queues.
+ */
+ ch->ch_r_head = 0;
+ ch->ch_r_tail = 0;
+ ch->ch_e_head = 0;
+ ch->ch_e_tail = 0;
+ ch->ch_w_head = 0;
+ ch->ch_w_tail = 0;
+
+ brd->bd_ops->flush_uart_write(ch);
+ brd->bd_ops->flush_uart_read(ch);
+
+ ch->ch_flags = 0;
+ ch->ch_cached_lsr = 0;
+ ch->ch_stop_sending_break = 0;
+ ch->ch_stops_sent = 0;
+
+ ch->ch_c_cflag = tty->termios.c_cflag;
+ ch->ch_c_iflag = tty->termios.c_iflag;
+ ch->ch_c_oflag = tty->termios.c_oflag;
+ ch->ch_c_lflag = tty->termios.c_lflag;
+ ch->ch_startc = tty->termios.c_cc[VSTART];
+ ch->ch_stopc = tty->termios.c_cc[VSTOP];
+
+ /*
+ * Bring up RTS and DTR...
+ * Also handle RTS or DTR toggle if set.
+ */
+ if (!(ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE))
+ ch->ch_mostat |= (UART_MCR_RTS);
+ if (!(ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE))
+ ch->ch_mostat |= (UART_MCR_DTR);
+
+ /* Tell UART to init itself */
+ brd->bd_ops->uart_init(ch);
+ }
+
+ /*
+ * Run param in case we changed anything
+ */
+ brd->bd_ops->param(tty);
+
+ dgnc_carrier(ch);
+
+ /*
+ * follow protocol for opening port
+ */
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ rc = dgnc_block_til_ready(tty, file, ch);
+
+ /* No going back now, increment our unit and channel counters */
+ spin_lock_irqsave(&ch->ch_lock, flags);
+ ch->ch_open_count++;
+ un->un_open_count++;
+ un->un_flags |= (UN_ISOPEN);
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ return rc;
+}
+
+
+/*
+ * dgnc_block_til_ready()
+ *
+ * Wait for DCD, if needed.
+ */
+static int dgnc_block_til_ready(struct tty_struct *tty, struct file *file, struct channel_t *ch)
+{
+ int retval = 0;
+ struct un_t *un = NULL;
+ unsigned long flags;
+ uint old_flags = 0;
+ int sleep_on_un_flags = 0;
+
+ if (!tty || tty->magic != TTY_MAGIC || !file || !ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return -ENXIO;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return -ENXIO;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_wopen++;
+
+ /* Loop forever */
+ while (1) {
+
+ sleep_on_un_flags = 0;
+
+ /*
+ * If board has failed somehow during our sleep, bail with error.
+ */
+ if (ch->ch_bd->state == BOARD_FAILED) {
+ retval = -ENXIO;
+ break;
+ }
+
+ /* If tty was hung up, break out of loop and set error. */
+ if (tty_hung_up_p(file)) {
+ retval = -EAGAIN;
+ break;
+ }
+
+ /*
+ * If either unit is in the middle of the fragile part of close,
+ * we just cannot touch the channel safely.
+ * Go back to sleep, knowing that when the channel can be
+ * touched safely, the close routine will signal the
+ * ch_wait_flags to wake us back up.
+ */
+ if (!((ch->ch_tun.un_flags | ch->ch_pun.un_flags) & UN_CLOSING)) {
+
+ /*
+ * Our conditions to leave cleanly and happily:
+ * 1) NONBLOCKING on the tty is set.
+ * 2) CLOCAL is set.
+ * 3) DCD (fake or real) is active.
+ */
+
+ if (file->f_flags & O_NONBLOCK)
+ break;
+
+ if (tty->flags & (1 << TTY_IO_ERROR)) {
+ retval = -EIO;
+ break;
+ }
+
+ if (ch->ch_flags & CH_CD)
+ break;
+
+ if (ch->ch_flags & CH_FCAR)
+ break;
+ } else {
+ sleep_on_un_flags = 1;
+ }
+
+ /*
+ * If there is a signal pending, the user probably
+ * interrupted (ctrl-c) us.
+ * Leave loop with error set.
+ */
+ if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ break;
+ }
+
+ /*
+ * Store the flags before we let go of channel lock
+ */
+ if (sleep_on_un_flags)
+ old_flags = ch->ch_tun.un_flags | ch->ch_pun.un_flags;
+ else
+ old_flags = ch->ch_flags;
+
+ /*
+ * Let go of channel lock before calling schedule.
+ * Our poller will get any FEP events and wake us up when DCD
+ * eventually goes active.
+ */
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ /*
+ * Wait for something in the flags to change from the current value.
+ */
+ if (sleep_on_un_flags)
+ retval = wait_event_interruptible(un->un_flags_wait,
+ (old_flags != (ch->ch_tun.un_flags | ch->ch_pun.un_flags)));
+ else
+ retval = wait_event_interruptible(ch->ch_flags_wait,
+ (old_flags != ch->ch_flags));
+
+ /*
+ * We got woken up for some reason.
+ * Before looping around, grab our channel lock.
+ */
+ spin_lock_irqsave(&ch->ch_lock, flags);
+ }
+
+ ch->ch_wopen--;
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ if (retval)
+ return retval;
+
+ return 0;
+}
+
+
+/*
+ * dgnc_tty_hangup()
+ *
+ * Hangup the port. Like a close, but don't wait for output to drain.
+ */
+static void dgnc_tty_hangup(struct tty_struct *tty)
+{
+ struct un_t *un;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return;
+
+ /* flush the transmit queues */
+ dgnc_tty_flush_buffer(tty);
+
+}
+
+
+/*
+ * dgnc_tty_close()
+ *
+ */
+static void dgnc_tty_close(struct tty_struct *tty, struct file *file)
+{
+ struct ktermios *ts;
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ unsigned long flags;
+ int rc = 0;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return;
+
+ ts = &tty->termios;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ /*
+ * Determine if this is the last close or not - and if we agree about
+ * which type of close it is with the Line Discipline
+ */
+ if ((tty->count == 1) && (un->un_open_count != 1)) {
+ /*
+ * Uh, oh. tty->count is 1, which means that the tty
+ * structure will be freed. un_open_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.
+ */
+ dev_dbg(tty->dev,
+ "tty->count is 1, un open count is %d\n",
+ un->un_open_count);
+ un->un_open_count = 1;
+ }
+
+ if (un->un_open_count)
+ un->un_open_count--;
+ else
+ dev_dbg(tty->dev,
+ "bad serial port open count of %d\n",
+ un->un_open_count);
+
+ ch->ch_open_count--;
+
+ if (ch->ch_open_count && un->un_open_count) {
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return;
+ }
+
+ /* OK, its the last close on the unit */
+ un->un_flags |= UN_CLOSING;
+
+ tty->closing = 1;
+
+
+ /*
+ * Only officially close channel if count is 0 and
+ * DIGI_PRINTER bit is not set.
+ */
+ if ((ch->ch_open_count == 0) && !(ch->ch_digi.digi_flags & DIGI_PRINTER)) {
+
+ ch->ch_flags &= ~(CH_STOPI | CH_FORCED_STOPI);
+
+ /*
+ * turn off print device when closing print device.
+ */
+ if ((un->un_type == DGNC_PRINT) && (ch->ch_flags & CH_PRON)) {
+ dgnc_wmove(ch, ch->ch_digi.digi_offstr,
+ (int) ch->ch_digi.digi_offlen);
+ ch->ch_flags &= ~CH_PRON;
+ }
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ /* wait for output to drain */
+ /* This will also return if we take an interrupt */
+
+ rc = bd->bd_ops->drain(tty, 0);
+
+ dgnc_tty_flush_buffer(tty);
+ tty_ldisc_flush(tty);
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ tty->closing = 0;
+
+ /*
+ * If we have HUPCL set, lower DTR and RTS
+ */
+ if (ch->ch_c_cflag & HUPCL) {
+
+ /* Drop RTS/DTR */
+ ch->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS);
+ bd->bd_ops->assert_modem_signals(ch);
+
+ /*
+ * Go to sleep to ensure RTS/DTR
+ * have been dropped for modems to see it.
+ */
+ if (ch->ch_close_delay) {
+ spin_unlock_irqrestore(&ch->ch_lock,
+ flags);
+ dgnc_ms_sleep(ch->ch_close_delay);
+ spin_lock_irqsave(&ch->ch_lock, flags);
+ }
+ }
+
+ ch->ch_old_baud = 0;
+
+ /* Turn off UART interrupts for this port */
+ ch->ch_bd->bd_ops->uart_off(ch);
+ } else {
+ /*
+ * turn off print device when closing print device.
+ */
+ if ((un->un_type == DGNC_PRINT) && (ch->ch_flags & CH_PRON)) {
+ dgnc_wmove(ch, ch->ch_digi.digi_offstr,
+ (int) ch->ch_digi.digi_offlen);
+ ch->ch_flags &= ~CH_PRON;
+ }
+ }
+
+ un->un_tty = NULL;
+ un->un_flags &= ~(UN_ISOPEN | UN_CLOSING);
+
+ wake_up_interruptible(&ch->ch_flags_wait);
+ wake_up_interruptible(&un->un_flags_wait);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+}
+
+
+/*
+ * dgnc_tty_chars_in_buffer()
+ *
+ * Return number of characters that have not been transmitted yet.
+ *
+ * This routine is used by the line discipline to determine if there
+ * is data waiting to be transmitted/drained/flushed or not.
+ */
+static int dgnc_tty_chars_in_buffer(struct tty_struct *tty)
+{
+ struct channel_t *ch = NULL;
+ struct un_t *un = NULL;
+ ushort thead;
+ ushort ttail;
+ uint tmask;
+ uint chars = 0;
+ unsigned long flags;
+
+ if (tty == NULL)
+ return 0;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return 0;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return 0;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ tmask = WQUEUEMASK;
+ thead = ch->ch_w_head & tmask;
+ ttail = ch->ch_w_tail & tmask;
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ if (ttail == thead) {
+ chars = 0;
+ } else {
+ if (thead >= ttail)
+ chars = thead - ttail;
+ else
+ chars = thead - ttail + WQUEUESIZE;
+ }
+
+ return chars;
+}
+
+
+/*
+ * dgnc_maxcps_room
+ *
+ * Reduces bytes_available to the max number of characters
+ * that can be sent currently given the maxcps value, and
+ * returns the new bytes_available. This only affects printer
+ * output.
+ */
+static int dgnc_maxcps_room(struct tty_struct *tty, int bytes_available)
+{
+ struct channel_t *ch = NULL;
+ struct un_t *un = NULL;
+
+ if (!tty)
+ return bytes_available;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return bytes_available;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return bytes_available;
+
+ /*
+ * If its not the Transparent print device, return
+ * the full data amount.
+ */
+ if (un->un_type != DGNC_PRINT)
+ return bytes_available;
+
+ if (ch->ch_digi.digi_maxcps > 0 && ch->ch_digi.digi_bufsize > 0) {
+ int cps_limit = 0;
+ unsigned long current_time = jiffies;
+ unsigned long buffer_time = current_time +
+ (HZ * ch->ch_digi.digi_bufsize) / ch->ch_digi.digi_maxcps;
+
+ if (ch->ch_cpstime < current_time) {
+ /* buffer is empty */
+ ch->ch_cpstime = current_time; /* reset ch_cpstime */
+ cps_limit = ch->ch_digi.digi_bufsize;
+ } else if (ch->ch_cpstime < buffer_time) {
+ /* still room in the buffer */
+ cps_limit = ((buffer_time - ch->ch_cpstime) * ch->ch_digi.digi_maxcps) / HZ;
+ } else {
+ /* no room in the buffer */
+ cps_limit = 0;
+ }
+
+ bytes_available = min(cps_limit, bytes_available);
+ }
+
+ return bytes_available;
+}
+
+
+/*
+ * dgnc_tty_write_room()
+ *
+ * Return space available in Tx buffer
+ */
+static int dgnc_tty_write_room(struct tty_struct *tty)
+{
+ struct channel_t *ch = NULL;
+ struct un_t *un = NULL;
+ ushort head;
+ ushort tail;
+ ushort tmask;
+ int ret = 0;
+ unsigned long flags;
+
+ if (tty == NULL || dgnc_TmpWriteBuf == NULL)
+ return 0;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return 0;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return 0;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ tmask = WQUEUEMASK;
+ head = (ch->ch_w_head) & tmask;
+ tail = (ch->ch_w_tail) & tmask;
+
+ ret = tail - head - 1;
+ if (ret < 0)
+ ret += WQUEUESIZE;
+
+ /* Limit printer to maxcps */
+ ret = dgnc_maxcps_room(tty, ret);
+
+ /*
+ * If we are printer device, leave space for
+ * possibly both the on and off strings.
+ */
+ if (un->un_type == DGNC_PRINT) {
+ if (!(ch->ch_flags & CH_PRON))
+ ret -= ch->ch_digi.digi_onlen;
+ ret -= ch->ch_digi.digi_offlen;
+ } else {
+ if (ch->ch_flags & CH_PRON)
+ ret -= ch->ch_digi.digi_offlen;
+ }
+
+ if (ret < 0)
+ ret = 0;
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ return ret;
+}
+
+
+/*
+ * dgnc_tty_put_char()
+ *
+ * Put a character into ch->ch_buf
+ *
+ * - used by the line discipline for OPOST processing
+ */
+static int dgnc_tty_put_char(struct tty_struct *tty, unsigned char c)
+{
+ /*
+ * Simply call tty_write.
+ */
+ dgnc_tty_write(tty, &c, 1);
+ return 1;
+}
+
+
+/*
+ * dgnc_tty_write()
+ *
+ * Take data from the user or kernel and send it out to the FEP.
+ * In here exists all the Transparent Print magic as well.
+ */
+static int dgnc_tty_write(struct tty_struct *tty,
+ const unsigned char *buf, int count)
+{
+ struct channel_t *ch = NULL;
+ struct un_t *un = NULL;
+ int bufcount = 0, n = 0;
+ int orig_count = 0;
+ unsigned long flags;
+ ushort head;
+ ushort tail;
+ ushort tmask;
+ uint remain;
+ int from_user = 0;
+
+ if (tty == NULL || dgnc_TmpWriteBuf == NULL)
+ return 0;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return 0;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return 0;
+
+ if (!count)
+ return 0;
+
+ /*
+ * Store original amount of characters passed in.
+ * This helps to figure out if we should ask the FEP
+ * to send us an event when it has more space available.
+ */
+ orig_count = count;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ /* Get our space available for the channel from the board */
+ tmask = WQUEUEMASK;
+ head = (ch->ch_w_head) & tmask;
+ tail = (ch->ch_w_tail) & tmask;
+
+ bufcount = tail - head - 1;
+ if (bufcount < 0)
+ bufcount += WQUEUESIZE;
+
+ /*
+ * Limit printer output to maxcps overall, with bursts allowed
+ * up to bufsize characters.
+ */
+ bufcount = dgnc_maxcps_room(tty, bufcount);
+
+ /*
+ * Take minimum of what the user wants to send, and the
+ * space available in the FEP buffer.
+ */
+ count = min(count, bufcount);
+
+ /*
+ * Bail if no space left.
+ */
+ if (count <= 0)
+ goto exit_retry;
+
+ /*
+ * Output the printer ON string, if we are in terminal mode, but
+ * need to be in printer mode.
+ */
+ if ((un->un_type == DGNC_PRINT) && !(ch->ch_flags & CH_PRON)) {
+ dgnc_wmove(ch, ch->ch_digi.digi_onstr,
+ (int) ch->ch_digi.digi_onlen);
+ head = (ch->ch_w_head) & tmask;
+ ch->ch_flags |= CH_PRON;
+ }
+
+ /*
+ * On the other hand, output the printer OFF string, if we are
+ * currently in printer mode, but need to output to the terminal.
+ */
+ if ((un->un_type != DGNC_PRINT) && (ch->ch_flags & CH_PRON)) {
+ dgnc_wmove(ch, ch->ch_digi.digi_offstr,
+ (int) ch->ch_digi.digi_offlen);
+ head = (ch->ch_w_head) & tmask;
+ ch->ch_flags &= ~CH_PRON;
+ }
+
+ /*
+ * If there is nothing left to copy, or I can't handle any more data, leave.
+ */
+ if (count <= 0)
+ goto exit_retry;
+
+ if (from_user) {
+
+ count = min(count, WRITEBUFLEN);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ /*
+ * If data is coming from user space, copy it into a temporary
+ * buffer so we don't get swapped out while doing the copy to
+ * the board.
+ */
+ /* we're allowed to block if it's from_user */
+ if (down_interruptible(&dgnc_TmpWriteSem))
+ return -EINTR;
+
+ /*
+ * copy_from_user() returns the number
+ * of bytes that could *NOT* be copied.
+ */
+ count -= copy_from_user(dgnc_TmpWriteBuf, (const unsigned char __user *) buf, count);
+
+ if (!count) {
+ up(&dgnc_TmpWriteSem);
+ return -EFAULT;
+ }
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ buf = dgnc_TmpWriteBuf;
+
+ }
+
+ n = count;
+
+ /*
+ * If the write wraps over the top of the circular buffer,
+ * move the portion up to the wrap point, and reset the
+ * pointers to the bottom.
+ */
+ remain = WQUEUESIZE - head;
+
+ if (n >= remain) {
+ n -= remain;
+ memcpy(ch->ch_wqueue + head, buf, remain);
+ head = 0;
+ buf += remain;
+ }
+
+ if (n > 0) {
+ /*
+ * Move rest of data.
+ */
+ remain = n;
+ memcpy(ch->ch_wqueue + head, buf, remain);
+ head += remain;
+ }
+
+ if (count) {
+ head &= tmask;
+ ch->ch_w_head = head;
+ }
+
+ /* Update printer buffer empty time. */
+ if ((un->un_type == DGNC_PRINT) && (ch->ch_digi.digi_maxcps > 0)
+ && (ch->ch_digi.digi_bufsize > 0)) {
+ ch->ch_cpstime += (HZ * count) / ch->ch_digi.digi_maxcps;
+ }
+
+ if (from_user) {
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ up(&dgnc_TmpWriteSem);
+ } else {
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ }
+
+ if (count) {
+ /*
+ * Channel lock is grabbed and then released
+ * inside this routine.
+ */
+ ch->ch_bd->bd_ops->copy_data_from_queue_to_uart(ch);
+ }
+
+ return count;
+
+exit_retry:
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return 0;
+}
+
+
+/*
+ * Return modem signals to ld.
+ */
+
+static int dgnc_tty_tiocmget(struct tty_struct *tty)
+{
+ struct channel_t *ch;
+ struct un_t *un;
+ int result = -EIO;
+ unsigned char mstat = 0;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return result;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return result;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return result;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ mstat = (ch->ch_mostat | ch->ch_mistat);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ result = 0;
+
+ if (mstat & UART_MCR_DTR)
+ result |= TIOCM_DTR;
+ if (mstat & UART_MCR_RTS)
+ result |= TIOCM_RTS;
+ if (mstat & UART_MSR_CTS)
+ result |= TIOCM_CTS;
+ if (mstat & UART_MSR_DSR)
+ result |= TIOCM_DSR;
+ if (mstat & UART_MSR_RI)
+ result |= TIOCM_RI;
+ if (mstat & UART_MSR_DCD)
+ result |= TIOCM_CD;
+
+ return result;
+}
+
+
+/*
+ * dgnc_tty_tiocmset()
+ *
+ * Set modem signals, called by ld.
+ */
+
+static int dgnc_tty_tiocmset(struct tty_struct *tty,
+ unsigned int set, unsigned int clear)
+{
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ int ret = -EIO;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return ret;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return ret;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return ret;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return ret;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ if (set & TIOCM_RTS)
+ ch->ch_mostat |= UART_MCR_RTS;
+
+ if (set & TIOCM_DTR)
+ ch->ch_mostat |= UART_MCR_DTR;
+
+ if (clear & TIOCM_RTS)
+ ch->ch_mostat &= ~(UART_MCR_RTS);
+
+ if (clear & TIOCM_DTR)
+ ch->ch_mostat &= ~(UART_MCR_DTR);
+
+ ch->ch_bd->bd_ops->assert_modem_signals(ch);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ return 0;
+}
+
+
+/*
+ * dgnc_tty_send_break()
+ *
+ * Send a Break, called by ld.
+ */
+static int dgnc_tty_send_break(struct tty_struct *tty, int msec)
+{
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ int ret = -EIO;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return ret;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return ret;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return ret;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return ret;
+
+ switch (msec) {
+ case -1:
+ msec = 0xFFFF;
+ break;
+ case 0:
+ msec = 0;
+ break;
+ default:
+ break;
+ }
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_bd->bd_ops->send_break(ch, msec);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ return 0;
+
+}
+
+
+/*
+ * dgnc_tty_wait_until_sent()
+ *
+ * wait until data has been transmitted, called by ld.
+ */
+static void dgnc_tty_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ int rc;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return;
+
+ rc = bd->bd_ops->drain(tty, 0);
+}
+
+
+/*
+ * dgnc_send_xchar()
+ *
+ * send a high priority character, called by ld.
+ */
+static void dgnc_tty_send_xchar(struct tty_struct *tty, char c)
+{
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return;
+
+ dev_dbg(tty->dev, "dgnc_tty_send_xchar start\n");
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+ bd->bd_ops->send_immediate_char(ch, c);
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ dev_dbg(tty->dev, "dgnc_tty_send_xchar finish\n");
+}
+
+
+
+
+/*
+ * Return modem signals to ld.
+ */
+static inline int dgnc_get_mstat(struct channel_t *ch)
+{
+ unsigned char mstat;
+ int result = -EIO;
+ unsigned long flags;
+
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return -ENXIO;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ mstat = (ch->ch_mostat | ch->ch_mistat);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ result = 0;
+
+ if (mstat & UART_MCR_DTR)
+ result |= TIOCM_DTR;
+ if (mstat & UART_MCR_RTS)
+ result |= TIOCM_RTS;
+ if (mstat & UART_MSR_CTS)
+ result |= TIOCM_CTS;
+ if (mstat & UART_MSR_DSR)
+ result |= TIOCM_DSR;
+ if (mstat & UART_MSR_RI)
+ result |= TIOCM_RI;
+ if (mstat & UART_MSR_DCD)
+ result |= TIOCM_CD;
+
+ return result;
+}
+
+
+
+/*
+ * Return modem signals to ld.
+ */
+static int dgnc_get_modem_info(struct channel_t *ch, unsigned int __user *value)
+{
+ int result;
+
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return -ENXIO;
+
+ result = dgnc_get_mstat(ch);
+
+ if (result < 0)
+ return -ENXIO;
+
+ return put_user(result, value);
+}
+
+
+/*
+ * dgnc_set_modem_info()
+ *
+ * Set modem signals, called by ld.
+ */
+static int dgnc_set_modem_info(struct tty_struct *tty, unsigned int command, unsigned int __user *value)
+{
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ int ret = -ENXIO;
+ unsigned int arg = 0;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return ret;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return ret;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return ret;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return ret;
+
+ ret = get_user(arg, value);
+ if (ret)
+ return ret;
+
+ switch (command) {
+ case TIOCMBIS:
+ if (arg & TIOCM_RTS)
+ ch->ch_mostat |= UART_MCR_RTS;
+
+ if (arg & TIOCM_DTR)
+ ch->ch_mostat |= UART_MCR_DTR;
+
+ break;
+
+ case TIOCMBIC:
+ if (arg & TIOCM_RTS)
+ ch->ch_mostat &= ~(UART_MCR_RTS);
+
+ if (arg & TIOCM_DTR)
+ ch->ch_mostat &= ~(UART_MCR_DTR);
+
+ break;
+
+ case TIOCMSET:
+
+ if (arg & TIOCM_RTS)
+ ch->ch_mostat |= UART_MCR_RTS;
+ else
+ ch->ch_mostat &= ~(UART_MCR_RTS);
+
+ if (arg & TIOCM_DTR)
+ ch->ch_mostat |= UART_MCR_DTR;
+ else
+ ch->ch_mostat &= ~(UART_MCR_DTR);
+
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_bd->bd_ops->assert_modem_signals(ch);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ return 0;
+}
+
+
+/*
+ * dgnc_tty_digigeta()
+ *
+ * Ioctl to get the information for ditty.
+ *
+ *
+ *
+ */
+static int dgnc_tty_digigeta(struct tty_struct *tty, struct digi_t __user *retinfo)
+{
+ struct channel_t *ch;
+ struct un_t *un;
+ struct digi_t tmp;
+ unsigned long flags;
+
+ if (!retinfo)
+ return -EFAULT;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return -EFAULT;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return -EFAULT;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return -EFAULT;
+
+ memset(&tmp, 0, sizeof(tmp));
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+ memcpy(&tmp, &ch->ch_digi, sizeof(tmp));
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
+ return -EFAULT;
+
+ return 0;
+}
+
+
+/*
+ * dgnc_tty_digiseta()
+ *
+ * Ioctl to set the information for ditty.
+ *
+ *
+ *
+ */
+static int dgnc_tty_digiseta(struct tty_struct *tty, struct digi_t __user *new_info)
+{
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ struct digi_t new_digi;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return -EFAULT;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return -EFAULT;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return -EFAULT;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return -EFAULT;
+
+ if (copy_from_user(&new_digi, new_info, sizeof(new_digi)))
+ return -EFAULT;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ /*
+ * Handle transistions to and from RTS Toggle.
+ */
+ if (!(ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE) && (new_digi.digi_flags & DIGI_RTS_TOGGLE))
+ ch->ch_mostat &= ~(UART_MCR_RTS);
+ if ((ch->ch_digi.digi_flags & DIGI_RTS_TOGGLE) && !(new_digi.digi_flags & DIGI_RTS_TOGGLE))
+ ch->ch_mostat |= (UART_MCR_RTS);
+
+ /*
+ * Handle transistions to and from DTR Toggle.
+ */
+ if (!(ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE) && (new_digi.digi_flags & DIGI_DTR_TOGGLE))
+ ch->ch_mostat &= ~(UART_MCR_DTR);
+ if ((ch->ch_digi.digi_flags & DIGI_DTR_TOGGLE) && !(new_digi.digi_flags & DIGI_DTR_TOGGLE))
+ ch->ch_mostat |= (UART_MCR_DTR);
+
+ memcpy(&ch->ch_digi, &new_digi, sizeof(new_digi));
+
+ if (ch->ch_digi.digi_maxcps < 1)
+ ch->ch_digi.digi_maxcps = 1;
+
+ if (ch->ch_digi.digi_maxcps > 10000)
+ ch->ch_digi.digi_maxcps = 10000;
+
+ if (ch->ch_digi.digi_bufsize < 10)
+ ch->ch_digi.digi_bufsize = 10;
+
+ if (ch->ch_digi.digi_maxchar < 1)
+ ch->ch_digi.digi_maxchar = 1;
+
+ if (ch->ch_digi.digi_maxchar > ch->ch_digi.digi_bufsize)
+ ch->ch_digi.digi_maxchar = ch->ch_digi.digi_bufsize;
+
+ if (ch->ch_digi.digi_onlen > DIGI_PLEN)
+ ch->ch_digi.digi_onlen = DIGI_PLEN;
+
+ if (ch->ch_digi.digi_offlen > DIGI_PLEN)
+ ch->ch_digi.digi_offlen = DIGI_PLEN;
+
+ ch->ch_bd->bd_ops->param(tty);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ return 0;
+}
+
+
+/*
+ * dgnc_set_termios()
+ */
+static void dgnc_tty_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
+{
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_c_cflag = tty->termios.c_cflag;
+ ch->ch_c_iflag = tty->termios.c_iflag;
+ ch->ch_c_oflag = tty->termios.c_oflag;
+ ch->ch_c_lflag = tty->termios.c_lflag;
+ ch->ch_startc = tty->termios.c_cc[VSTART];
+ ch->ch_stopc = tty->termios.c_cc[VSTOP];
+
+ ch->ch_bd->bd_ops->param(tty);
+ dgnc_carrier(ch);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+}
+
+
+static void dgnc_tty_throttle(struct tty_struct *tty)
+{
+ struct channel_t *ch;
+ struct un_t *un;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_flags |= (CH_FORCED_STOPI);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+}
+
+
+static void dgnc_tty_unthrottle(struct tty_struct *tty)
+{
+ struct channel_t *ch;
+ struct un_t *un;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_flags &= ~(CH_FORCED_STOPI);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+}
+
+
+static void dgnc_tty_start(struct tty_struct *tty)
+{
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_flags &= ~(CH_FORCED_STOP);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+}
+
+
+static void dgnc_tty_stop(struct tty_struct *tty)
+{
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_flags |= (CH_FORCED_STOP);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+}
+
+
+/*
+ * dgnc_tty_flush_chars()
+ *
+ * Flush the cook buffer
+ *
+ * Note to self, and any other poor souls who venture here:
+ *
+ * flush in this case DOES NOT mean dispose of the data.
+ * instead, it means "stop buffering and send it if you
+ * haven't already." Just guess how I figured that out... SRW 2-Jun-98
+ *
+ * It is also always called in interrupt context - JAR 8-Sept-99
+ */
+static void dgnc_tty_flush_chars(struct tty_struct *tty)
+{
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ /* Do something maybe here */
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+}
+
+
+
+/*
+ * dgnc_tty_flush_buffer()
+ *
+ * Flush Tx buffer (make in == out)
+ */
+static void dgnc_tty_flush_buffer(struct tty_struct *tty)
+{
+ struct channel_t *ch;
+ struct un_t *un;
+ unsigned long flags;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_flags &= ~CH_STOP;
+
+ /* Flush our write queue */
+ ch->ch_w_head = ch->ch_w_tail;
+
+ /* Flush UARTs transmit FIFO */
+ ch->ch_bd->bd_ops->flush_uart_write(ch);
+
+ if (ch->ch_tun.un_flags & (UN_LOW|UN_EMPTY)) {
+ ch->ch_tun.un_flags &= ~(UN_LOW|UN_EMPTY);
+ wake_up_interruptible(&ch->ch_tun.un_flags_wait);
+ }
+ if (ch->ch_pun.un_flags & (UN_LOW|UN_EMPTY)) {
+ ch->ch_pun.un_flags &= ~(UN_LOW|UN_EMPTY);
+ wake_up_interruptible(&ch->ch_pun.un_flags_wait);
+ }
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+}
+
+
+
+/*****************************************************************************
+ *
+ * The IOCTL function and all of its helpers
+ *
+ *****************************************************************************/
+
+/*
+ * dgnc_tty_ioctl()
+ *
+ * The usual assortment of ioctl's
+ */
+static int dgnc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
+ unsigned long arg)
+{
+ struct dgnc_board *bd;
+ struct channel_t *ch;
+ struct un_t *un;
+ int rc;
+ unsigned long flags;
+ void __user *uarg = (void __user *) arg;
+
+ if (!tty || tty->magic != TTY_MAGIC)
+ return -ENODEV;
+
+ un = tty->driver_data;
+ if (!un || un->magic != DGNC_UNIT_MAGIC)
+ return -ENODEV;
+
+ ch = un->un_ch;
+ if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
+ return -ENODEV;
+
+ bd = ch->ch_bd;
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return -ENODEV;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ if (un->un_open_count <= 0) {
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return -EIO;
+ }
+
+ switch (cmd) {
+
+ /* Here are all the standard ioctl's that we MUST implement */
+
+ case TCSBRK:
+ /*
+ * TCSBRK is SVID version: non-zero arg --> no break
+ * this behaviour is exploited by tcdrain().
+ *
+ * According to POSIX.1 spec (7.2.2.1.2) breaks should be
+ * between 0.25 and 0.5 seconds so we'll ask for something
+ * in the middle: 0.375 seconds.
+ */
+ rc = tty_check_change(tty);
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ if (rc)
+ return rc;
+
+ rc = ch->ch_bd->bd_ops->drain(tty, 0);
+
+ if (rc)
+ return -EINTR;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ if (((cmd == TCSBRK) && (!arg)) || (cmd == TCSBRKP))
+ ch->ch_bd->bd_ops->send_break(ch, 250);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ return 0;
+
+
+ case TCSBRKP:
+ /* support for POSIX tcsendbreak()
+ * According to POSIX.1 spec (7.2.2.1.2) breaks should be
+ * between 0.25 and 0.5 seconds so we'll ask for something
+ * in the middle: 0.375 seconds.
+ */
+ rc = tty_check_change(tty);
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ if (rc)
+ return rc;
+
+ rc = ch->ch_bd->bd_ops->drain(tty, 0);
+ if (rc)
+ return -EINTR;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_bd->bd_ops->send_break(ch, 250);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ return 0;
+
+ case TIOCSBRK:
+ rc = tty_check_change(tty);
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ if (rc)
+ return rc;
+
+ rc = ch->ch_bd->bd_ops->drain(tty, 0);
+ if (rc)
+ return -EINTR;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ ch->ch_bd->bd_ops->send_break(ch, 250);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ return 0;
+
+ case TIOCCBRK:
+ /* Do Nothing */
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return 0;
+
+ case TIOCGSOFTCAR:
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ rc = put_user(C_CLOCAL(tty) ? 1 : 0, (unsigned long __user *) arg);
+ return rc;
+
+ case TIOCSSOFTCAR:
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ rc = get_user(arg, (unsigned long __user *) arg);
+ if (rc)
+ return rc;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+ tty->termios.c_cflag = ((tty->termios.c_cflag & ~CLOCAL) | (arg ? CLOCAL : 0));
+ ch->ch_bd->bd_ops->param(tty);
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ return 0;
+
+ case TIOCMGET:
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return dgnc_get_modem_info(ch, uarg);
+
+ case TIOCMBIS:
+ case TIOCMBIC:
+ case TIOCMSET:
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return dgnc_set_modem_info(tty, cmd, uarg);
+
+ /*
+ * Here are any additional ioctl's that we want to implement
+ */
+
+ case TCFLSH:
+ /*
+ * The linux tty driver doesn't have a flush
+ * input routine for the driver, assuming all backed
+ * up data is in the line disc. buffers. However,
+ * we all know that's not the case. Here, we
+ * act on the ioctl, but then lie and say we didn't
+ * so the line discipline will process the flush
+ * also.
+ */
+ rc = tty_check_change(tty);
+ if (rc) {
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return rc;
+ }
+
+ if ((arg == TCIFLUSH) || (arg == TCIOFLUSH)) {
+ ch->ch_r_head = ch->ch_r_tail;
+ ch->ch_bd->bd_ops->flush_uart_read(ch);
+ /* Force queue flow control to be released, if needed */
+ dgnc_check_queue_flow_control(ch);
+ }
+
+ if ((arg == TCOFLUSH) || (arg == TCIOFLUSH)) {
+ if (!(un->un_type == DGNC_PRINT)) {
+ ch->ch_w_head = ch->ch_w_tail;
+ ch->ch_bd->bd_ops->flush_uart_write(ch);
+
+ if (ch->ch_tun.un_flags & (UN_LOW|UN_EMPTY)) {
+ ch->ch_tun.un_flags &= ~(UN_LOW|UN_EMPTY);
+ wake_up_interruptible(&ch->ch_tun.un_flags_wait);
+ }
+
+ if (ch->ch_pun.un_flags & (UN_LOW|UN_EMPTY)) {
+ ch->ch_pun.un_flags &= ~(UN_LOW|UN_EMPTY);
+ wake_up_interruptible(&ch->ch_pun.un_flags_wait);
+ }
+
+ }
+ }
+
+ /* pretend we didn't recognize this IOCTL */
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return -ENOIOCTLCMD;
+ case TCSETSF:
+ case TCSETSW:
+ /*
+ * The linux tty driver doesn't have a flush
+ * input routine for the driver, assuming all backed
+ * up data is in the line disc. buffers. However,
+ * we all know that's not the case. Here, we
+ * act on the ioctl, but then lie and say we didn't
+ * so the line discipline will process the flush
+ * also.
+ */
+ if (cmd == TCSETSF) {
+ /* flush rx */
+ ch->ch_flags &= ~CH_STOP;
+ ch->ch_r_head = ch->ch_r_tail;
+ ch->ch_bd->bd_ops->flush_uart_read(ch);
+ /* Force queue flow control to be released, if needed */
+ dgnc_check_queue_flow_control(ch);
+ }
+
+ /* now wait for all the output to drain */
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ rc = ch->ch_bd->bd_ops->drain(tty, 0);
+ if (rc)
+ return -EINTR;
+
+ /* pretend we didn't recognize this */
+ return -ENOIOCTLCMD;
+
+ case TCSETAW:
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ rc = ch->ch_bd->bd_ops->drain(tty, 0);
+ if (rc)
+ return -EINTR;
+
+ /* pretend we didn't recognize this */
+ return -ENOIOCTLCMD;
+
+ case TCXONC:
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ /* Make the ld do it */
+ return -ENOIOCTLCMD;
+
+ case DIGI_GETA:
+ /* get information for ditty */
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return dgnc_tty_digigeta(tty, uarg);
+
+ case DIGI_SETAW:
+ case DIGI_SETAF:
+
+ /* set information for ditty */
+ if (cmd == (DIGI_SETAW)) {
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ rc = ch->ch_bd->bd_ops->drain(tty, 0);
+
+ if (rc)
+ return -EINTR;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+ } else {
+ tty_ldisc_flush(tty);
+ }
+ /* fall thru */
+
+ case DIGI_SETA:
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return dgnc_tty_digiseta(tty, uarg);
+
+ case DIGI_LOOPBACK:
+ {
+ uint loopback = 0;
+ /* Let go of locks when accessing user space, could sleep */
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ rc = get_user(loopback, (unsigned int __user *) arg);
+ if (rc)
+ return rc;
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ /* Enable/disable internal loopback for this port */
+ if (loopback)
+ ch->ch_flags |= CH_LOOPBACK;
+ else
+ ch->ch_flags &= ~(CH_LOOPBACK);
+
+ ch->ch_bd->bd_ops->param(tty);
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return 0;
+ }
+
+ case DIGI_GETCUSTOMBAUD:
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ rc = put_user(ch->ch_custom_speed, (unsigned int __user *) arg);
+ return rc;
+
+ case DIGI_SETCUSTOMBAUD:
+ {
+ int new_rate;
+ /* Let go of locks when accessing user space, could sleep */
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ rc = get_user(new_rate, (int __user *) arg);
+ if (rc)
+ return rc;
+ spin_lock_irqsave(&ch->ch_lock, flags);
+ dgnc_set_custom_speed(ch, new_rate);
+ ch->ch_bd->bd_ops->param(tty);
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return 0;
+ }
+
+ /*
+ * This ioctl allows insertion of a character into the front
+ * of any pending data to be transmitted.
+ *
+ * This ioctl is to satify the "Send Character Immediate"
+ * call that the RealPort protocol spec requires.
+ */
+ case DIGI_REALPORT_SENDIMMEDIATE:
+ {
+ unsigned char c;
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ rc = get_user(c, (unsigned char __user *) arg);
+ if (rc)
+ return rc;
+ spin_lock_irqsave(&ch->ch_lock, flags);
+ ch->ch_bd->bd_ops->send_immediate_char(ch, c);
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ return 0;
+ }
+
+ /*
+ * This ioctl returns all the current counts for the port.
+ *
+ * This ioctl is to satify the "Line Error Counters"
+ * call that the RealPort protocol spec requires.
+ */
+ case DIGI_REALPORT_GETCOUNTERS:
+ {
+ struct digi_getcounter buf;
+
+ buf.norun = ch->ch_err_overrun;
+ buf.noflow = 0; /* The driver doesn't keep this stat */
+ buf.nframe = ch->ch_err_frame;
+ buf.nparity = ch->ch_err_parity;
+ buf.nbreak = ch->ch_err_break;
+ buf.rbytes = ch->ch_rxcount;
+ buf.tbytes = ch->ch_txcount;
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ if (copy_to_user(uarg, &buf, sizeof(buf)))
+ return -EFAULT;
+
+ return 0;
+ }
+
+ /*
+ * This ioctl returns all current events.
+ *
+ * This ioctl is to satify the "Event Reporting"
+ * call that the RealPort protocol spec requires.
+ */
+ case DIGI_REALPORT_GETEVENTS:
+ {
+ unsigned int events = 0;
+
+ /* NOTE: MORE EVENTS NEEDS TO BE ADDED HERE */
+ if (ch->ch_flags & CH_BREAK_SENDING)
+ events |= EV_TXB;
+ if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_FORCED_STOP))
+ events |= (EV_OPU | EV_OPS);
+
+ if ((ch->ch_flags & CH_STOPI) || (ch->ch_flags & CH_FORCED_STOPI))
+ events |= (EV_IPU | EV_IPS);
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+ rc = put_user(events, (unsigned int __user *) arg);
+ return rc;
+ }
+
+ /*
+ * This ioctl returns TOUT and TIN counters based
+ * upon the values passed in by the RealPort Server.
+ * It also passes back whether the UART Transmitter is
+ * empty as well.
+ */
+ case DIGI_REALPORT_GETBUFFERS:
+ {
+ struct digi_getbuffer buf;
+ int tdist;
+ int count;
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ /*
+ * Get data from user first.
+ */
+ if (copy_from_user(&buf, uarg, sizeof(buf)))
+ return -EFAULT;
+
+ spin_lock_irqsave(&ch->ch_lock, flags);
+
+ /*
+ * Figure out how much data is in our RX and TX queues.
+ */
+ buf.rxbuf = (ch->ch_r_head - ch->ch_r_tail) & RQUEUEMASK;
+ buf.txbuf = (ch->ch_w_head - ch->ch_w_tail) & WQUEUEMASK;
+
+ /*
+ * Is the UART empty? Add that value to whats in our TX queue.
+ */
+ count = buf.txbuf + ch->ch_bd->bd_ops->get_uart_bytes_left(ch);
+
+ /*
+ * Figure out how much data the RealPort Server believes should
+ * be in our TX queue.
+ */
+ tdist = (buf.tIn - buf.tOut) & 0xffff;
+
+ /*
+ * If we have more data than the RealPort Server believes we
+ * should have, reduce our count to its amount.
+ *
+ * This count difference CAN happen because the Linux LD can
+ * insert more characters into our queue for OPOST processing
+ * that the RealPort Server doesn't know about.
+ */
+ if (buf.txbuf > tdist)
+ buf.txbuf = tdist;
+
+ /*
+ * Report whether our queue and UART TX are completely empty.
+ */
+ if (count)
+ buf.txdone = 0;
+ else
+ buf.txdone = 1;
+
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ if (copy_to_user(uarg, &buf, sizeof(buf)))
+ return -EFAULT;
+
+ return 0;
+ }
+ default:
+ spin_unlock_irqrestore(&ch->ch_lock, flags);
+
+ return -ENOIOCTLCMD;
+ }
+}
Code Review / kvmfornfv.git / blobdiff