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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [lib/] [libc/] [termios.c] - Rev 751
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/* * TERMIOS serial line support * * Author: * W. Eric Norum * Saskatchewan Accelerator Laboratory * University of Saskatchewan * Saskatoon, Saskatchewan, CANADA * eric@skatter.usask.ca * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at * http://www.OARcorp.com/rtems/license.html. * * $Id: termios.c,v 1.2 2001-09-27 12:01:15 chris Exp $ */ #include <rtems.h> #include <rtems/libio.h> #include <ctype.h> #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <termios.h> #include <unistd.h> /* * FreeBSD does not support a full POSIX termios so we have to help it out */ #if defined(__FreeBSD__) #define XTABS 0 #define ONLRET 0 #define ONOCR 0 #define TABDLY 0 #define OLCUC 0 #define ILCUC 0 #define OCRNL 0 #define IUCLC 0 #endif /* * Cygwin does not define these */ #if defined(__CYGWIN__) #define ECHOPRT 0 #endif /* * The size of the cooked buffer */ #define CBUFSIZE 256 /* * The sizes of the raw message buffers. * On most architectures it is quite a bit more * efficient if these are powers of two. */ #define RAW_INPUT_BUFFER_SIZE 128 #define RAW_OUTPUT_BUFFER_SIZE 64 /* * Variables associated with each termios instance. * One structure for each hardware I/O device. */ struct rtems_termios_tty { /* * Linked-list of active TERMIOS devices */ struct rtems_termios_tty *forw; struct rtems_termios_tty *back; /* * How many times has this device been opened */ int refcount; /* * This device */ rtems_device_major_number major; rtems_device_major_number minor; /* * Mutual-exclusion semaphores */ rtems_id isem; rtems_id osem; /* * The canonical (cooked) character buffer */ char cbuf[CBUFSIZE]; int ccount; int cindex; /* * Keep track of cursor (printhead) position */ int column; int read_start_column; /* * The ioctl settings */ struct termios termios; rtems_interval vtimeTicks; /* * Raw input character buffer */ volatile char rawInBuf[RAW_INPUT_BUFFER_SIZE]; volatile unsigned int rawInBufHead; volatile unsigned int rawInBufTail; rtems_id rawInBufSemaphore; rtems_unsigned32 rawInBufSemaphoreOptions; rtems_interval rawInBufSemaphoreTimeout; rtems_interval rawInBufSemaphoreFirstTimeout; unsigned int rawInBufDropped; /* Statistics */ /* * Raw output character buffer */ volatile char rawOutBuf[RAW_OUTPUT_BUFFER_SIZE]; volatile unsigned int rawOutBufHead; volatile unsigned int rawOutBufTail; rtems_id rawOutBufSemaphore; enum {rob_idle, rob_busy, rob_wait } rawOutBufState; /* * Callbacks to device-specific routines */ rtems_termios_callbacks device; volatile unsigned int flow_ctrl; unsigned int lowwater,highwater; }; /* fields for "flow_ctrl" status */ #define FL_IREQXOF 1 /* input queue requests stop of incoming data */ #define FL_ISNTXOF 2 /* XOFF has been sent to other side of line */ #define FL_IRTSOFF 4 /* RTS has been turned off for other side.. */ #define FL_ORCVXOF 0x10 /* XOFF has been received */ #define FL_OSTOP 0x20 /* output has been stopped due to XOFF */ #define FL_MDRTS 0x100 /* input controlled with RTS/CTS handshake */ #define FL_MDXON 0x200 /* input controlled with XON/XOFF protocol */ #define FL_MDXOF 0x400 /* output controlled with XON/XOFF protocol */ extern struct rtems_termios_tty *rtems_termios_ttyHead; extern struct rtems_termios_tty *rtems_termios_ttyTail; extern rtems_id rtems_termios_ttyMutex; /* * Open a termios device */ rtems_status_code rtems_termios_open ( rtems_device_major_number major, rtems_device_minor_number minor, void *arg, const rtems_termios_callbacks *callbacks ) { rtems_status_code sc; rtems_libio_open_close_args_t *args = arg; struct rtems_termios_tty *tty; /* * See if the device has already been opened */ sc = rtems_semaphore_obtain (rtems_termios_ttyMutex, RTEMS_WAIT, RTEMS_NO_TIMEOUT); if (sc != RTEMS_SUCCESSFUL) return sc; for (tty = rtems_termios_ttyHead ; tty != NULL ; tty = tty->forw) { if ((tty->major == major) && (tty->minor == minor)) break; } if (tty == NULL) { static char c = 'a'; /* * Create a new device */ tty = calloc (1, sizeof (struct rtems_termios_tty)); if (tty == NULL) { rtems_semaphore_release (rtems_termios_ttyMutex); return RTEMS_NO_MEMORY; } if (rtems_termios_ttyHead) rtems_termios_ttyHead->back = tty; tty->forw = rtems_termios_ttyHead; rtems_termios_ttyHead = tty; if (rtems_termios_ttyTail == NULL) rtems_termios_ttyTail = tty; tty->minor = minor; tty->major = major; /* * Set up mutex semaphores */ sc = rtems_semaphore_create ( rtems_build_name ('T', 'R', 'i', c), 1, RTEMS_BINARY_SEMAPHORE | RTEMS_INHERIT_PRIORITY | RTEMS_PRIORITY, RTEMS_NO_PRIORITY, &tty->isem); if (sc != RTEMS_SUCCESSFUL) rtems_fatal_error_occurred (sc); sc = rtems_semaphore_create ( rtems_build_name ('T', 'R', 'o', c), 1, RTEMS_BINARY_SEMAPHORE | RTEMS_INHERIT_PRIORITY | RTEMS_PRIORITY, RTEMS_NO_PRIORITY, &tty->osem); if (sc != RTEMS_SUCCESSFUL) rtems_fatal_error_occurred (sc); sc = rtems_semaphore_create ( rtems_build_name ('T', 'R', 'x', c), 0, RTEMS_COUNTING_SEMAPHORE | RTEMS_PRIORITY, RTEMS_NO_PRIORITY, &tty->rawOutBufSemaphore); if (sc != RTEMS_SUCCESSFUL) rtems_fatal_error_occurred (sc); tty->rawOutBufState = rob_idle; /* * Set callbacks */ tty->device = *callbacks; if (!tty->device.pollRead) { sc = rtems_semaphore_create ( rtems_build_name ('T', 'R', 'r', c), 0, RTEMS_COUNTING_SEMAPHORE | RTEMS_PRIORITY, RTEMS_NO_PRIORITY, &tty->rawInBufSemaphore); if (sc != RTEMS_SUCCESSFUL) rtems_fatal_error_occurred (sc); } /* * Set default parameters */ tty->termios.c_iflag = BRKINT | ICRNL | IMAXBEL; tty->termios.c_oflag = OPOST | ONLCR | XTABS; tty->termios.c_cflag = B9600 | CS8 | CREAD | CLOCAL; tty->termios.c_lflag = ISIG | ICANON | IEXTEN | ECHO | ECHOK | ECHOE | ECHOCTL; tty->termios.c_cc[VINTR] = '\003'; tty->termios.c_cc[VQUIT] = '\034'; tty->termios.c_cc[VERASE] = '\177'; tty->termios.c_cc[VKILL] = '\025'; tty->termios.c_cc[VEOF] = '\004'; tty->termios.c_cc[VEOL] = '\000'; tty->termios.c_cc[VEOL2] = '\000'; tty->termios.c_cc[VSTART] = '\021'; tty->termios.c_cc[VSTOP] = '\023'; tty->termios.c_cc[VSUSP] = '\032'; tty->termios.c_cc[VREPRINT] = '\022'; tty->termios.c_cc[VDISCARD] = '\017'; tty->termios.c_cc[VWERASE] = '\027'; tty->termios.c_cc[VLNEXT] = '\026'; /* start with no flow control, clear flow control flags */ tty->flow_ctrl = 0; /* * set low/highwater mark for XON/XOFF support */ tty->lowwater = RAW_INPUT_BUFFER_SIZE * 1/2; tty->highwater = RAW_INPUT_BUFFER_SIZE * 3/4; /* * Bump name characer */ if (c++ == 'z') c = 'a'; } args->iop->data1 = tty; if (!tty->refcount++ && tty->device.firstOpen) (*tty->device.firstOpen)(major, minor, arg); rtems_semaphore_release (rtems_termios_ttyMutex); return RTEMS_SUCCESSFUL; } /* * Drain output queue */ static void drainOutput (struct rtems_termios_tty *tty) { rtems_interrupt_level level; rtems_status_code sc; if (tty->device.outputUsesInterrupts) { rtems_interrupt_disable (level); while (tty->rawOutBufTail != tty->rawOutBufHead) { tty->rawOutBufState = rob_wait; rtems_interrupt_enable (level); sc = rtems_semaphore_obtain (tty->rawOutBufSemaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT); if (sc != RTEMS_SUCCESSFUL) rtems_fatal_error_occurred (sc); rtems_interrupt_disable (level); } rtems_interrupt_enable (level); } } rtems_status_code rtems_termios_close (void *arg) { rtems_libio_open_close_args_t *args = arg; struct rtems_termios_tty *tty = args->iop->data1; rtems_status_code sc; sc = rtems_semaphore_obtain (rtems_termios_ttyMutex, RTEMS_WAIT, RTEMS_NO_TIMEOUT); if (sc != RTEMS_SUCCESSFUL) rtems_fatal_error_occurred (sc); if (--tty->refcount == 0) { drainOutput (tty); if (tty->device.lastClose) (*tty->device.lastClose)(tty->major, tty->minor, arg); if (tty->forw == NULL) rtems_termios_ttyTail = tty->back; else tty->forw->back = tty->back; if (tty->back == NULL) rtems_termios_ttyHead = tty->forw; else tty->back->forw = tty->forw; rtems_semaphore_delete (tty->isem); rtems_semaphore_delete (tty->osem); rtems_semaphore_delete (tty->rawOutBufSemaphore); if (!tty->device.pollRead) rtems_semaphore_delete (tty->rawInBufSemaphore); free (tty); } rtems_semaphore_release (rtems_termios_ttyMutex); return RTEMS_SUCCESSFUL; } static void termios_set_flowctrl(struct rtems_termios_tty *tty) { rtems_interrupt_level level; /* * check for flow control options to be switched off */ /* check for outgoing XON/XOFF flow control switched off */ if (( tty->flow_ctrl & FL_MDXON) && !(tty->termios.c_iflag & IXON)) { /* clear related flags in flow_ctrl */ tty->flow_ctrl &= ~(FL_MDXON | FL_ORCVXOF); /* has output been stopped due to received XOFF? */ if (tty->flow_ctrl & FL_OSTOP) { /* disable interrupts */ rtems_interrupt_disable(level); tty->flow_ctrl &= ~FL_OSTOP; /* check for chars in output buffer (or rob_state?) */ if (tty->rawOutBufState != rob_idle) { /* if chars available, call write function... */ (*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[tty->rawOutBufTail], 1); } /* reenable interrupts */ rtems_interrupt_enable(level); } } /* check for incoming XON/XOFF flow control switched off */ if (( tty->flow_ctrl & FL_MDXOF) && !(tty->termios.c_iflag & IXOFF)) { /* clear related flags in flow_ctrl */ tty->flow_ctrl &= ~(FL_MDXOF); /* FIXME: what happens, if we had sent XOFF but not yet XON? */ tty->flow_ctrl &= ~(FL_ISNTXOF); } /* check for incoming RTS/CTS flow control switched off */ if (( tty->flow_ctrl & FL_MDRTS) && !(tty->termios.c_cflag & CRTSCTS)) { /* clear related flags in flow_ctrl */ tty->flow_ctrl &= ~(FL_MDRTS); /* restart remote Tx, if it was stopped */ if ((tty->flow_ctrl & FL_IRTSOFF) && (tty->device.startRemoteTx != NULL)) { tty->device.startRemoteTx(tty->minor); } tty->flow_ctrl &= ~(FL_IRTSOFF); } /* * check for flow control options to be switched on */ /* check for incoming RTS/CTS flow control switched on */ if (tty->termios.c_cflag & CRTSCTS) { tty->flow_ctrl |= FL_MDRTS; } /* check for incoming XON/XOF flow control switched on */ if (tty->termios.c_iflag & IXOFF) { tty->flow_ctrl |= FL_MDXOF; } /* check for outgoing XON/XOF flow control switched on */ if (tty->termios.c_iflag & IXON) { tty->flow_ctrl |= FL_MDXON; } } rtems_status_code rtems_termios_ioctl (void *arg) { rtems_libio_ioctl_args_t *args = arg; struct rtems_termios_tty *tty = args->iop->data1; rtems_status_code sc; args->ioctl_return = 0; sc = rtems_semaphore_obtain (tty->osem, RTEMS_WAIT, RTEMS_NO_TIMEOUT); if (sc != RTEMS_SUCCESSFUL) { args->ioctl_return = sc; return sc; } switch (args->command) { default: sc = RTEMS_INVALID_NUMBER; break; case RTEMS_IO_GET_ATTRIBUTES: *(struct termios *)args->buffer = tty->termios; break; case RTEMS_IO_SET_ATTRIBUTES: tty->termios = *(struct termios *)args->buffer; /* check for and process change in flow control options */ termios_set_flowctrl(tty); if (tty->termios.c_lflag & ICANON) { tty->rawInBufSemaphoreOptions = RTEMS_WAIT; tty->rawInBufSemaphoreTimeout = RTEMS_NO_TIMEOUT; tty->rawInBufSemaphoreFirstTimeout = RTEMS_NO_TIMEOUT; } else { rtems_interval ticksPerSecond; rtems_clock_get (RTEMS_CLOCK_GET_TICKS_PER_SECOND, &ticksPerSecond); tty->vtimeTicks = tty->termios.c_cc[VTIME] * ticksPerSecond / 10; if (tty->termios.c_cc[VTIME]) { tty->rawInBufSemaphoreOptions = RTEMS_WAIT; tty->rawInBufSemaphoreTimeout = tty->vtimeTicks; if (tty->termios.c_cc[VMIN]) tty->rawInBufSemaphoreFirstTimeout = RTEMS_NO_TIMEOUT; else tty->rawInBufSemaphoreFirstTimeout = tty->vtimeTicks; } else { if (tty->termios.c_cc[VMIN]) { tty->rawInBufSemaphoreOptions = RTEMS_WAIT; tty->rawInBufSemaphoreTimeout = RTEMS_NO_TIMEOUT; tty->rawInBufSemaphoreFirstTimeout = RTEMS_NO_TIMEOUT; } else { tty->rawInBufSemaphoreOptions = RTEMS_NO_WAIT; } } } if (tty->device.setAttributes) (*tty->device.setAttributes)(tty->minor, &tty->termios); break; case RTEMS_IO_TCDRAIN: drainOutput (tty); break; } rtems_semaphore_release (tty->osem); args->ioctl_return = sc; return sc; } /* * Send characters to device-specific code */ static void osend (const char *buf, int len, struct rtems_termios_tty *tty) { unsigned int newHead; rtems_interrupt_level level; rtems_status_code sc; if (!tty->device.outputUsesInterrupts) { (*tty->device.write)(tty->minor, buf, len); return; } newHead = tty->rawOutBufHead; while (len) { /* * Performance improvement could be made here. * Copy multiple bytes to raw buffer: * if (len > 1) && (space to buffer end, or tail > 1) * ncopy = MIN (len, space to buffer end or tail) * memcpy (raw buffer, buf, ncopy) * buf += ncopy * len -= ncopy * * To minimize latency, the memcpy should be done * with interrupts enabled. */ newHead = (newHead + 1) % RAW_OUTPUT_BUFFER_SIZE; rtems_interrupt_disable (level); while (newHead == tty->rawOutBufTail) { tty->rawOutBufState = rob_wait; rtems_interrupt_enable (level); sc = rtems_semaphore_obtain (tty->rawOutBufSemaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT); if (sc != RTEMS_SUCCESSFUL) rtems_fatal_error_occurred (sc); rtems_interrupt_disable (level); } tty->rawOutBuf[tty->rawOutBufHead] = *buf++; tty->rawOutBufHead = newHead; if (tty->rawOutBufState == rob_idle) { /* check, whether XOFF has been received */ if (!(tty->flow_ctrl & FL_ORCVXOF)) { (*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[tty->rawOutBufTail],1); } else { /* remember that output has been stopped due to flow ctrl*/ tty->flow_ctrl |= FL_OSTOP; } tty->rawOutBufState = rob_busy; } rtems_interrupt_enable (level); len--; } } /* * Handle output processing */ static void oproc (unsigned char c, struct rtems_termios_tty *tty) { int i; if (tty->termios.c_oflag & OPOST) { switch (c) { case '\n': if (tty->termios.c_oflag & ONLRET) tty->column = 0; if (tty->termios.c_oflag & ONLCR) { osend ("\r", 1, tty); tty->column = 0; } break; case '\r': if ((tty->termios.c_oflag & ONOCR) && (tty->column == 0)) return; if (tty->termios.c_oflag & OCRNL) { c = '\n'; if (tty->termios.c_oflag & ONLRET) tty->column = 0; break; } tty->column = 0; break; case '\t': i = 8 - (tty->column & 7); if ((tty->termios.c_oflag & TABDLY) == XTABS) { tty->column += i; osend ( " ", i, tty); return; } tty->column += i; break; case '\b': if (tty->column > 0) tty->column--; break; default: if (tty->termios.c_oflag & OLCUC) c = toupper(c); if (!iscntrl(c)) tty->column++; break; } } osend (&c, 1, tty); } rtems_status_code rtems_termios_write (void *arg) { rtems_libio_rw_args_t *args = arg; struct rtems_termios_tty *tty = args->iop->data1; rtems_status_code sc; sc = rtems_semaphore_obtain (tty->osem, RTEMS_WAIT, RTEMS_NO_TIMEOUT); if (sc != RTEMS_SUCCESSFUL) return sc; if (tty->termios.c_oflag & OPOST) { unsigned32 count = args->count; unsigned8 *buffer = args->buffer; while (count--) oproc (*buffer++, tty); args->bytes_moved = args->count; } else { osend (args->buffer, args->count, tty); args->bytes_moved = args->count; } rtems_semaphore_release (tty->osem); return sc; } /* * Echo a typed character */ static void echo (unsigned char c, struct rtems_termios_tty *tty) { if ((tty->termios.c_lflag & ECHOCTL) && iscntrl(c) && (c != '\t') && (c != '\n')) { char echobuf[2]; echobuf[0] = '^'; echobuf[1] = c ^ 0x40; osend (echobuf, 2, tty); tty->column += 2; } else { oproc (c, tty); } } /* * Erase a character or line * FIXME: Needs support for WERASE and ECHOPRT. * FIXME: Some of the tests should check for IEXTEN, too. */ static void erase (struct rtems_termios_tty *tty, int lineFlag) { if (tty->ccount == 0) return; if (lineFlag) { if (!(tty->termios.c_lflag & ECHO)) { tty->ccount = 0; return; } if (!(tty->termios.c_lflag & ECHOE)) { tty->ccount = 0; echo (tty->termios.c_cc[VKILL], tty); if (tty->termios.c_lflag & ECHOK) echo ('\n', tty); return; } } while (tty->ccount) { unsigned char c = tty->cbuf[--tty->ccount]; if (tty->termios.c_lflag & ECHO) { if (!lineFlag && !(tty->termios.c_lflag & ECHOE)) { echo (tty->termios.c_cc[VERASE], tty); } else if (c == '\t') { int col = tty->read_start_column; int i = 0; /* * Find the character before the tab */ while (i != tty->ccount) { c = tty->cbuf[i++]; if (c == '\t') { col = (col | 7) + 1; } else if (iscntrl (c)) { if (tty->termios.c_lflag & ECHOCTL) col += 2; } else { col++; } } /* * Back up over the tab */ while (tty->column > col) { osend ("\b", 1, tty); tty->column--; } } else { if (iscntrl (c) && (tty->termios.c_lflag & ECHOCTL)) { osend ("\b \b", 3, tty); if (tty->column) tty->column--; } if (!iscntrl (c) || (tty->termios.c_lflag & ECHOCTL)) { osend ("\b \b", 3, tty); if (tty->column) tty->column--; } } } if (!lineFlag) break; } } /* * Process a single input character */ static int iproc (unsigned char c, struct rtems_termios_tty *tty) { if (tty->termios.c_iflag & ISTRIP) c &= 0x7f; if (tty->termios.c_iflag & IUCLC) c = tolower (c); if (c == '\r') { if (tty->termios.c_iflag & IGNCR) return 0; if (tty->termios.c_iflag & ICRNL) c = '\n'; } else if ((c == '\n') && (tty->termios.c_iflag & INLCR)) { c = '\r'; } if ((c != '\0') && (tty->termios.c_lflag & ICANON)) { if (c == tty->termios.c_cc[VERASE]) { erase (tty, 0); return 0; } else if (c == tty->termios.c_cc[VKILL]) { erase (tty, 1); return 0; } else if (c == tty->termios.c_cc[VEOF]) { return 1; } else if (c == '\n') { if (tty->termios.c_lflag & (ECHO | ECHONL)) echo (c, tty); tty->cbuf[tty->ccount++] = c; return 1; } else if ((c == tty->termios.c_cc[VEOL]) || (c == tty->termios.c_cc[VEOL2])) { if (tty->termios.c_lflag & ECHO) echo (c, tty); tty->cbuf[tty->ccount++] = c; return 1; } } /* * FIXME: Should do IMAXBEL handling somehow */ if (tty->ccount < (CBUFSIZE-1)) { if (tty->termios.c_lflag & ECHO) echo (c, tty); tty->cbuf[tty->ccount++] = c; } return 0; } /* * Process input character, with semaphore. */ static int siproc (unsigned char c, struct rtems_termios_tty *tty) { int i; /* * Obtain output semaphore if character will be echoed */ if (tty->termios.c_lflag & (ECHO|ECHOE|ECHOK|ECHONL|ECHOPRT|ECHOCTL|ECHOKE)) { rtems_semaphore_obtain (tty->osem, RTEMS_WAIT, RTEMS_NO_TIMEOUT); i = iproc (c, tty); rtems_semaphore_release (tty->osem); } else { i = iproc (c, tty); } return i; } /* * Fill the input buffer by polling the device */ static rtems_status_code fillBufferPoll (struct rtems_termios_tty *tty) { int n; if (tty->termios.c_lflag & ICANON) { for (;;) { n = (*tty->device.pollRead)(tty->minor); if (n < 0) { rtems_task_wake_after (1); } else { if (siproc (n, tty)) break; } } } else { rtems_interval then, now; if (!tty->termios.c_cc[VMIN] && tty->termios.c_cc[VTIME]) rtems_clock_get (RTEMS_CLOCK_GET_TICKS_SINCE_BOOT, &then); for (;;) { n = (*tty->device.pollRead)(tty->minor); if (n < 0) { if (tty->termios.c_cc[VMIN]) { if (tty->termios.c_cc[VTIME] && tty->ccount) { rtems_clock_get (RTEMS_CLOCK_GET_TICKS_SINCE_BOOT, &now); if ((now - then) > tty->vtimeTicks) { break; } } } else { if (!tty->termios.c_cc[VTIME]) break; rtems_clock_get (RTEMS_CLOCK_GET_TICKS_SINCE_BOOT, &now); if ((now - then) > tty->vtimeTicks) { break; } } rtems_task_wake_after (1); } else { siproc (n, tty); if (tty->ccount >= tty->termios.c_cc[VMIN]) break; if (tty->termios.c_cc[VMIN] && tty->termios.c_cc[VTIME]) rtems_clock_get (RTEMS_CLOCK_GET_TICKS_SINCE_BOOT, &then); } } } return RTEMS_SUCCESSFUL; } /* * Fill the input buffer from the raw input queue */ static rtems_status_code fillBufferQueue (struct rtems_termios_tty *tty) { rtems_interval timeout = tty->rawInBufSemaphoreFirstTimeout; rtems_status_code sc; for (;;) { /* * Process characters read from raw queue */ while (tty->rawInBufHead != tty->rawInBufTail) { unsigned char c; unsigned int newHead; newHead = (tty->rawInBufHead + 1) % RAW_INPUT_BUFFER_SIZE; c = tty->rawInBuf[newHead]; tty->rawInBufHead = newHead; if(((tty->rawInBufTail-newHead+RAW_INPUT_BUFFER_SIZE) % RAW_INPUT_BUFFER_SIZE) < tty->lowwater) { tty->flow_ctrl &= ~FL_IREQXOF; /* if tx stopped and XON should be sent... */ if (((tty->flow_ctrl & (FL_MDXON | FL_ISNTXOF)) == (FL_MDXON | FL_ISNTXOF)) && ((tty->rawOutBufState == rob_idle) || (tty->flow_ctrl & FL_OSTOP))) { /* XON should be sent now... */ (*tty->device.write)(tty->minor, &(tty->termios.c_cc[VSTART]), 1); } else if (tty->flow_ctrl & FL_MDRTS) { tty->flow_ctrl &= ~FL_IRTSOFF; /* activate RTS line */ if (tty->device.startRemoteTx != NULL) { tty->device.startRemoteTx(tty->minor); } } } /* continue processing new character */ if (tty->termios.c_lflag & ICANON) { if (siproc (c, tty)) return RTEMS_SUCCESSFUL; } else { siproc (c, tty); if (tty->ccount >= tty->termios.c_cc[VMIN]) return RTEMS_SUCCESSFUL; } timeout = tty->rawInBufSemaphoreTimeout; } /* * Wait for characters */ sc = rtems_semaphore_obtain (tty->rawInBufSemaphore, tty->rawInBufSemaphoreOptions, timeout); if (sc != RTEMS_SUCCESSFUL) break; } return RTEMS_SUCCESSFUL; } rtems_status_code rtems_termios_read (void *arg) { rtems_libio_rw_args_t *args = arg; struct rtems_termios_tty *tty = args->iop->data1; unsigned32 count = args->count; unsigned8 *buffer = args->buffer; rtems_status_code sc; sc = rtems_semaphore_obtain (tty->isem, RTEMS_WAIT, RTEMS_NO_TIMEOUT); if (sc != RTEMS_SUCCESSFUL) return sc; if (tty->cindex == tty->ccount) { tty->cindex = tty->ccount = 0; tty->read_start_column = tty->column; if (tty->device.pollRead) sc = fillBufferPoll (tty); else sc = fillBufferQueue (tty); if (sc != RTEMS_SUCCESSFUL) tty->cindex = tty->ccount = 0; } while (count && (tty->cindex < tty->ccount)) { *buffer++ = tty->cbuf[tty->cindex++]; count--; } args->bytes_moved = args->count - count; rtems_semaphore_release (tty->isem); return sc; } /* * Place characters on raw queue. * NOTE: This routine runs in the context of the * device receive interrupt handler. * Returns the number of characters dropped because of overflow. */ int rtems_termios_enqueue_raw_characters (void *ttyp, char *buf, int len) { struct rtems_termios_tty *tty = ttyp; unsigned int newTail; char c; int dropped = 0; boolean flow_rcv = FALSE; /* TRUE, if flow control char received */ rtems_interrupt_level level; while (len--) { c = *buf++; /* FIXME: implement IXANY: any character restarts output */ /* if incoming XON/XOFF controls outgoing stream: */ if (tty->flow_ctrl & FL_MDXON) { /* if received char is V_STOP and V_START (both are equal value) */ if (c == tty->termios.c_cc[VSTOP]) { if (c == tty->termios.c_cc[VSTART]) { /* received VSTOP and VSTART==VSTOP? */ /* then toggle "stop output" status */ tty->flow_ctrl = tty->flow_ctrl ^ FL_ORCVXOF; } else { /* VSTOP received (other code than VSTART) */ /* stop output */ tty->flow_ctrl |= FL_ORCVXOF; } flow_rcv = TRUE; } else if (c == tty->termios.c_cc[VSTART]) { /* VSTART received */ /* restart output */ tty->flow_ctrl &= ~FL_ORCVXOF; flow_rcv = TRUE; } } if (flow_rcv) { /* restart output according to FL_ORCVXOF flag */ if ((tty->flow_ctrl & (FL_ORCVXOF | FL_OSTOP)) == FL_OSTOP) { /* disable interrupts */ rtems_interrupt_disable(level); tty->flow_ctrl &= ~FL_OSTOP; /* check for chars in output buffer (or rob_state?) */ if (tty->rawOutBufState != rob_idle) { /* if chars available, call write function... */ (*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[tty->rawOutBufTail], 1); } /* reenable interrupts */ rtems_interrupt_enable(level); } } else { newTail = (tty->rawInBufTail + 1) % RAW_INPUT_BUFFER_SIZE; /* if chars_in_buffer > highwater */ rtems_interrupt_disable(level); if ((((newTail - tty->rawInBufHead + RAW_INPUT_BUFFER_SIZE) % RAW_INPUT_BUFFER_SIZE) > tty->highwater) && !(tty->flow_ctrl & FL_IREQXOF)) { /* incoming data stream should be stopped */ tty->flow_ctrl |= FL_IREQXOF; if ((tty->flow_ctrl & (FL_MDXOF | FL_ISNTXOF)) == (FL_MDXOF ) ){ if ((tty->flow_ctrl & FL_OSTOP) || (tty->rawOutBufState == rob_idle)) { /* if tx is stopped due to XOFF or out of data */ /* call write function here */ tty->flow_ctrl |= FL_ISNTXOF; (*tty->device.write)(tty->minor, &(tty->termios.c_cc[VSTOP]), 1); } } else if ((tty->flow_ctrl & (FL_MDRTS | FL_IRTSOFF)) == (FL_MDRTS ) ) { tty->flow_ctrl |= FL_IRTSOFF; /* deactivate RTS line */ if (tty->device.stopRemoteTx != NULL) { tty->device.stopRemoteTx(tty->minor); } } } /* reenable interrupts */ rtems_interrupt_enable(level); if (newTail == tty->rawInBufHead) { dropped++; } else { tty->rawInBuf[newTail] = c; tty->rawInBufTail = newTail; } } } tty->rawInBufDropped += dropped; rtems_semaphore_release (tty->rawInBufSemaphore); return dropped; } /* * Characters have been transmitted * NOTE: This routine runs in the context of the * device transmit interrupt handler. * The second argument is the number of characters transmitted so far. * This value will always be 1 for devices which generate an interrupt * for each transmitted character. * It returns number of characters left to transmit */ int rtems_termios_dequeue_characters (void *ttyp, int len) { struct rtems_termios_tty *tty = ttyp; unsigned int newTail; int nToSend; /* check for XOF/XON to send */ if ((tty->flow_ctrl & (FL_MDXOF | FL_IREQXOF | FL_ISNTXOF)) == (FL_MDXOF | FL_IREQXOF)) { /* XOFF should be sent now... */ (*tty->device.write)(tty->minor, &(tty->termios.c_cc[VSTOP]), 1); tty->flow_ctrl |= FL_ISNTXOF; nToSend = 1; } else if ((tty->flow_ctrl & (FL_IREQXOF | FL_ISNTXOF)) == FL_ISNTXOF) { /* NOTE: send XON even, if no longer in XON/XOFF mode... */ /* XON should be sent now... */ (*tty->device.write)(tty->minor, &(tty->termios.c_cc[VSTART]), 1); tty->flow_ctrl &= ~FL_ISNTXOF; nToSend = 1; } else { if (tty->rawOutBufState == rob_wait) rtems_semaphore_release (tty->rawOutBufSemaphore); if ( tty->rawOutBufHead == tty->rawOutBufTail ) return 0; newTail = (tty->rawOutBufTail + len) % RAW_OUTPUT_BUFFER_SIZE; if (newTail == tty->rawOutBufHead) { /* * Buffer empty */ tty->rawOutBufState = rob_idle; nToSend = 0; } /* check, whether output should stop due to received XOFF */ else if ((tty->flow_ctrl & (FL_MDXON | FL_ORCVXOF)) == (FL_MDXON | FL_ORCVXOF)) { /* Buffer not empty, but output stops due to XOFF */ /* set flag, that output has been stopped */ tty->flow_ctrl |= FL_OSTOP; nToSend = 0; } else { /* * Buffer not empty, start tranmitter */ if (newTail > tty->rawOutBufHead) nToSend = RAW_OUTPUT_BUFFER_SIZE - newTail; else nToSend = tty->rawOutBufHead - newTail; /* when flow control XON or XOF, don't send blocks of data */ /* to allow fast reaction on incoming flow ctrl and low latency*/ /* for outgoing flow control */ if (tty->flow_ctrl & (FL_MDXON | FL_MDXOF)) { nToSend = 1; } (*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[newTail], nToSend); tty->rawOutBufState = rob_busy; } tty->rawOutBufTail = newTail; } return nToSend; }
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