/* * linux/drivers/char/core.c * * Driver core for serial ports * * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * * Copyright 1999 ARM Limited * Copyright (C) 2000-2001 Deep Blue Solutions Ltd. * * 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 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include #include #include #include #include #include #include #include #include /* for serial_state and serial_icounter_struct */ #include #include #include #include /* * This is used to lock changes in serial line configuration. */ static DEFINE_MUTEX(port_mutex); /* * lockdep: port->lock is initialized in two places, but we * want only one lock-class: */ static struct lock_class_key port_lock_key; #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8) #define uart_users(state) ((state)->count + ((state)->info ? (state)->info->blocked_open : 0)) #ifdef CONFIG_SERIAL_CORE_CONSOLE #define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line) #else #define uart_console(port) (0) #endif static void uart_change_speed(struct uart_state *state, struct ktermios *old_termios); static void uart_wait_until_sent(struct tty_struct *tty, int timeout); static void uart_change_pm(struct uart_state *state, int pm_state); /* * This routine is used by the interrupt handler to schedule processing in * the software interrupt portion of the driver. */ void uart_write_wakeup(struct uart_port *port) { struct uart_info *info = port->info; /* * This means you called this function _after_ the port was * closed. No cookie for you. */ BUG_ON(!info); tasklet_schedule(&info->tlet); } static void uart_stop(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; unsigned long flags; spin_lock_irqsave(&port->lock, flags); port->ops->stop_tx(port); spin_unlock_irqrestore(&port->lock, flags); } static void __uart_start(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf && !tty->stopped && !tty->hw_stopped) port->ops->start_tx(port); } static void uart_start(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; unsigned long flags; spin_lock_irqsave(&port->lock, flags); __uart_start(tty); spin_unlock_irqrestore(&port->lock, flags); } static void uart_tasklet_action(unsigned long data) { struct uart_state *state = (struct uart_state *)data; tty_wakeup(state->info->tty); } static inline void uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear) { unsigned long flags; unsigned int old; spin_lock_irqsave(&port->lock, flags); old = port->mctrl; port->mctrl = (old & ~clear) | set; if (old != port->mctrl) port->ops->set_mctrl(port, port->mctrl); spin_unlock_irqrestore(&port->lock, flags); } #define uart_set_mctrl(port,set) uart_update_mctrl(port,set,0) #define uart_clear_mctrl(port,clear) uart_update_mctrl(port,0,clear) /* * Startup the port. This will be called once per open. All calls * will be serialised by the per-port semaphore. */ static int uart_startup(struct uart_state *state, int init_hw) { struct uart_info *info = state->info; struct uart_port *port = state->port; unsigned long page; int retval = 0; if (info->flags & UIF_INITIALIZED) return 0; /* * Set the TTY IO error marker - we will only clear this * once we have successfully opened the port. Also set * up the tty->alt_speed kludge */ set_bit(TTY_IO_ERROR, &info->tty->flags); if (port->type == PORT_UNKNOWN) return 0; /* * Initialise and allocate the transmit and temporary * buffer. */ if (!info->xmit.buf) { page = get_zeroed_page(GFP_KERNEL); if (!page) return -ENOMEM; info->xmit.buf = (unsigned char *) page; uart_circ_clear(&info->xmit); } retval = port->ops->startup(port); if (retval == 0) { if (init_hw) { /* * Initialise the hardware port settings. */ uart_change_speed(state, NULL); /* * Setup the RTS and DTR signals once the * port is open and ready to respond. */ if (info->tty->termios->c_cflag & CBAUD) uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR); } if (info->flags & UIF_CTS_FLOW) { spin_lock_irq(&port->lock); if (!(port->ops->get_mctrl(port) & TIOCM_CTS)) info->tty->hw_stopped = 1; spin_unlock_irq(&port->lock); } info->flags |= UIF_INITIALIZED; clear_bit(TTY_IO_ERROR, &info->tty->flags); } if (retval && capable(CAP_SYS_ADMIN)) retval = 0; return retval; } /* * This routine will shutdown a serial port; interrupts are disabled, and * DTR is dropped if the hangup on close termio flag is on. Calls to * uart_shutdown are serialised by the per-port semaphore. */ static void uart_shutdown(struct uart_state *state) { struct uart_info *info = state->info; struct uart_port *port = state->port; /* * Set the TTY IO error marker */ if (info->tty) set_bit(TTY_IO_ERROR, &info->tty->flags); if (info->flags & UIF_INITIALIZED) { info->flags &= ~UIF_INITIALIZED; /* * Turn off DTR and RTS early. */ if (!info->tty || (info->tty->termios->c_cflag & HUPCL)) uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS); /* * clear delta_msr_wait queue to avoid mem leaks: we may free * the irq here so the queue might never be woken up. Note * that we won't end up waiting on delta_msr_wait again since * any outstanding file descriptors should be pointing at * hung_up_tty_fops now. */ wake_up_interruptible(&info->delta_msr_wait); /* * Free the IRQ and disable the port. */ port->ops->shutdown(port); /* * Ensure that the IRQ handler isn't running on another CPU. */ synchronize_irq(port->irq); } /* * kill off our tasklet */ tasklet_kill(&info->tlet); /* * Free the transmit buffer page. */ if (info->xmit.buf) { free_page((unsigned long)info->xmit.buf); info->xmit.buf = NULL; } } /** * uart_update_timeout - update per-port FIFO timeout. * @port: uart_port structure describing the port * @cflag: termios cflag value * @baud: speed of the port * * Set the port FIFO timeout value. The @cflag value should * reflect the actual hardware settings. */ void uart_update_timeout(struct uart_port *port, unsigned int cflag, unsigned int baud) { unsigned int bits; /* byte size and parity */ switch (cflag & CSIZE) { case CS5: bits = 7; break; case CS6: bits = 8; break; case CS7: bits = 9; break; default: bits = 10; break; // CS8 } if (cflag & CSTOPB) bits++; if (cflag & PARENB) bits++; /* * The total number of bits to be transmitted in the fifo. */ bits = bits * port->fifosize; /* * Figure the timeout to send the above number of bits. * Add .02 seconds of slop */ port->timeout = (HZ * bits) / baud + HZ/50; } EXPORT_SYMBOL(uart_update_timeout); /** * uart_get_baud_rate - return baud rate for a particular port * @port: uart_port structure describing the port in question. * @termios: desired termios settings. * @old: old termios (or NULL) * @min: minimum acceptable baud rate * @max: maximum acceptable baud rate * * Decode the termios structure into a numeric baud rate, * taking account of the magic 38400 baud rate (with spd_* * flags), and mapping the %B0 rate to 9600 baud. * * If the new baud rate is invalid, try the old termios setting. * If it's still invalid, we try 9600 baud. * * Update the @termios structure to reflect the baud rate * we're actually going to be using. */ unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, struct ktermios *old, unsigned int min, unsigned int max) { unsigned int try, baud, altbaud = 38400; upf_t flags = port->flags & UPF_SPD_MASK; if (flags == UPF_SPD_HI) altbaud = 57600; if (flags == UPF_SPD_VHI) altbaud = 115200; if (flags == UPF_SPD_SHI) altbaud = 230400; if (flags == UPF_SPD_WARP) altbaud = 460800; for (try = 0; try < 2; try++) { baud = tty_termios_baud_rate(termios); /* * The spd_hi, spd_vhi, spd_shi, spd_warp kludge... * Die! Die! Die! */ if (baud == 38400) baud = altbaud; /* * Special case: B0 rate. */ if (baud == 0) baud = 9600; if (baud >= min && baud <= max) return baud; /* * Oops, the quotient was zero. Try again with * the old baud rate if possible. */ termios->c_cflag &= ~CBAUD; if (old) { termios->c_cflag |= old->c_cflag & CBAUD; old = NULL; continue; } /* * As a last resort, if the quotient is zero, * default to 9600 bps */ termios->c_cflag |= B9600; } return 0; } EXPORT_SYMBOL(uart_get_baud_rate); /** * uart_get_divisor - return uart clock divisor * @port: uart_port structure describing the port. * @baud: desired baud rate * * Calculate the uart clock divisor for the port. */ unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud) { unsigned int quot; /* * Old custom speed handling. */ if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) quot = port->custom_divisor; else quot = (port->uartclk + (8 * baud)) / (16 * baud); return quot; } EXPORT_SYMBOL(uart_get_divisor); static void uart_change_speed(struct uart_state *state, struct ktermios *old_termios) { struct tty_struct *tty = state->info->tty; struct uart_port *port = state->port; struct ktermios *termios; /* * If we have no tty, termios, or the port does not exist, * then we can't set the parameters for this port. */ if (!tty || !tty->termios || port->type == PORT_UNKNOWN) return; termios = tty->termios; /* * Set flags based on termios cflag */ if (termios->c_cflag & CRTSCTS) state->info->flags |= UIF_CTS_FLOW; else state->info->flags &= ~UIF_CTS_FLOW; if (termios->c_cflag & CLOCAL) state->info->flags &= ~UIF_CHECK_CD; else state->info->flags |= UIF_CHECK_CD; port->ops->set_termios(port, termios, old_termios); } static inline void __uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c) { unsigned long flags; if (!circ->buf) return; spin_lock_irqsave(&port->lock, flags); if (uart_circ_chars_free(circ) != 0) { circ->buf[circ->head] = c; circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1); } spin_unlock_irqrestore(&port->lock, flags); } static void uart_put_char(struct tty_struct *tty, unsigned char ch) { struct uart_state *state = tty->driver_data; __uart_put_char(state->port, &state->info->xmit, ch); } static void uart_flush_chars(struct tty_struct *tty) { uart_start(tty); } static int uart_write(struct tty_struct *tty, const unsigned char *buf, int count) { struct uart_state *state = tty->driver_data; struct uart_port *port; struct circ_buf *circ; unsigned long flags; int c, ret = 0; /* * This means you called this function _after_ the port was * closed. No cookie for you. */ if (!state || !state->info) { WARN_ON(1); return -EL3HLT; } port = state->port; circ = &state->info->xmit; if (!circ->buf) return 0; spin_lock_irqsave(&port->lock, flags); while (1) { c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE); if (count < c) c = count; if (c <= 0) break; memcpy(circ->buf + circ->head, buf, c); circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1); buf += c; count -= c; ret += c; } spin_unlock_irqrestore(&port->lock, flags); uart_start(tty); return ret; } static int uart_write_room(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; return uart_circ_chars_free(&state->info->xmit); } static int uart_chars_in_buffer(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; return uart_circ_chars_pending(&state->info->xmit); } static void uart_flush_buffer(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; unsigned long flags; /* * This means you called this function _after_ the port was * closed. No cookie for you. */ if (!state || !state->info) { WARN_ON(1); return; } pr_debug("uart_flush_buffer(%d) called\n", tty->index); spin_lock_irqsave(&port->lock, flags); uart_circ_clear(&state->info->xmit); spin_unlock_irqrestore(&port->lock, flags); tty_wakeup(tty); } /* * This function is used to send a high-priority XON/XOFF character to * the device */ static void uart_send_xchar(struct tty_struct *tty, char ch) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; unsigned long flags; if (port->ops->send_xchar) port->ops->send_xchar(port, ch); else { port->x_char = ch; if (ch) { spin_lock_irqsave(&port->lock, flags); port->ops->start_tx(port); spin_unlock_irqrestore(&port->lock, flags); } } } static void uart_throttle(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; if (I_IXOFF(tty)) uart_send_xchar(tty, STOP_CHAR(tty)); if (tty->termios->c_cflag & CRTSCTS) uart_clear_mctrl(state->port, TIOCM_RTS); } static void uart_unthrottle(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; if (I_IXOFF(tty)) { if (port->x_char) port->x_char = 0; else uart_send_xchar(tty, START_CHAR(tty)); } if (tty->termios->c_cflag & CRTSCTS) uart_set_mctrl(port, TIOCM_RTS); } static int uart_get_info(struct uart_state *state, struct serial_struct __user *retinfo) { struct uart_port *port = state->port; struct serial_struct tmp; memset(&tmp, 0, sizeof(tmp)); tmp.type = port->type; tmp.line = port->line; tmp.port = port->iobase; if (HIGH_BITS_OFFSET) tmp.port_high = (long) port->iobase >> HIGH_BITS_OFFSET; tmp.irq = port->irq; tmp.flags = port->flags; tmp.xmit_fifo_size = port->fifosize; tmp.baud_base = port->uartclk / 16; tmp.close_delay = state->close_delay / 10; tmp.closing_wait = state->closing_wait == USF_CLOSING_WAIT_NONE ? ASYNC_CLOSING_WAIT_NONE : state->closing_wait / 10; tmp.custom_divisor = port->custom_divisor; tmp.hub6 = port->hub6; tmp.io_type = port->iotype; tmp.iomem_reg_shift = port->regshift; tmp.iomem_base = (void *)(unsigned long)port->mapbase; if (copy_to_user(retinfo, &tmp, sizeof(*retinfo))) return -EFAULT; return 0; } static int uart_set_info(struct uart_state *state, struct serial_struct __user *newinfo) { struct serial_struct new_serial; struct uart_port *port = state->port; unsigned long new_port; unsigned int change_irq, change_port, closing_wait; unsigned int old_custom_divisor, close_delay; upf_t old_flags, new_flags; int retval = 0; if (copy_from_user(&new_serial, newinfo, sizeof(new_serial))) return -EFAULT; new_port = new_serial.port; if (HIGH_BITS_OFFSET) new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET; new_serial.irq = irq_canonicalize(new_serial.irq); close_delay = new_serial.close_delay * 10; closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ? USF_CLOSING_WAIT_NONE : new_serial.closing_wait * 10; /* * This semaphore protects state->count. It is also * very useful to prevent opens. Also, take the * port configuration semaphore to make sure that a * module insertion/removal doesn't change anything * under us. */ mutex_lock(&state->mutex); change_irq = !(port->flags & UPF_FIXED_PORT) && new_serial.irq != port->irq; /* * Since changing the 'type' of the port changes its resource * allocations, we should treat type changes the same as * IO port changes. */ change_port = !(port->flags & UPF_FIXED_PORT) && (new_port != port->iobase || (unsigned long)new_serial.iomem_base != port->mapbase || new_serial.hub6 != port->hub6 || new_serial.io_type != port->iotype || new_serial.iomem_reg_shift != port->regshift || new_serial.type != port->type); old_flags = port->flags; new_flags = new_serial.flags; old_custom_divisor = port->custom_divisor; if (!capable(CAP_SYS_ADMIN)) { retval = -EPERM; if (change_irq || change_port || (new_serial.baud_base != port->uartclk / 16) || (close_delay != state->close_delay) || (closing_wait != state->closing_wait) || (new_serial.xmit_fifo_size && new_serial.xmit_fifo_size != port->fifosize) || (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0)) goto exit; port->flags = ((port->flags & ~UPF_USR_MASK) | (new_flags & UPF_USR_MASK)); port->custom_divisor = new_serial.custom_divisor; goto check_and_exit; } /* * Ask the low level driver to verify the settings. */ if (port->ops->verify_port) retval = port->ops->verify_port(port, &new_serial); if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) || (new_serial.baud_base < 9600)) retval = -EINVAL; if (retval) goto exit; if (change_port || change_irq) { retval = -EBUSY; /* * Make sure that we are the sole user of this port. */ if (uart_users(state) > 1) goto exit; /* * We need to shutdown the serial port at the old * port/type/irq combination. */ uart_shutdown(state); } if (change_port) { unsigned long old_iobase, old_mapbase; unsigned int old_type, old_iotype, old_hub6, old_shift; old_iobase = port->iobase; old_mapbase = port->mapbase; old_type = port->type; old_hub6 = port->hub6; old_iotype = port->iotype; old_shift = port->regshift; /* * Free and release old regions */ if (old_type != PORT_UNKNOWN) port->ops->release_port(port); port->iobase = new_port; port->type = new_serial.type; port->hub6 = new_serial.hub6; port->iotype = new_serial.io_type; port->regshift = new_serial.iomem_reg_shift; port->mapbase = (unsigned long)new_serial.iomem_base; /* * Claim and map the new regions */ if (port->type != PORT_UNKNOWN) { retval = port->ops->request_port(port); } else { /* Always success - Jean II */ retval = 0; } /* * If we fail to request resources for the * new port, try to restore the old settings. */ if (retval && old_type != PORT_UNKNOWN) { port->iobase = old_iobase; port->type = old_type; port->hub6 = old_hub6; port->iotype = old_iotype; port->regshift = old_shift; port->mapbase = old_mapbase; retval = port->ops->request_port(port); /* * If we failed to restore the old settings, * we fail like this. */ if (retval) port->type = PORT_UNKNOWN; /* * We failed anyway. */ retval = -EBUSY; goto exit; // Added to return the correct error -Ram Gupta } } if (change_irq) port->irq = new_serial.irq; if (!(port->flags & UPF_FIXED_PORT)) port->uartclk = new_serial.baud_base * 16; port->flags = (port->flags & ~UPF_CHANGE_MASK) | (new_flags & UPF_CHANGE_MASK); port->custom_divisor = new_serial.custom_divisor; state->close_delay = close_delay; state->closing_wait = closing_wait; if (new_serial.xmit_fifo_size) port->fifosize = new_serial.xmit_fifo_size; if (state->info->tty) state->info->tty->low_latency = (port->flags & UPF_LOW_LATENCY) ? 1 : 0; check_and_exit: retval = 0; if (port->type == PORT_UNKNOWN) goto exit; if (state->info->flags & UIF_INITIALIZED) { if (((old_flags ^ port->flags) & UPF_SPD_MASK) || old_custom_divisor != port->custom_divisor) { /* * If they're setting up a custom divisor or speed, * instead of clearing it, then bitch about it. No * need to rate-limit; it's CAP_SYS_ADMIN only. */ if (port->flags & UPF_SPD_MASK) { char buf[64]; printk(KERN_NOTICE "%s sets custom speed on %s. This " "is deprecated.\n", current->comm, tty_name(state->info->tty, buf)); } uart_change_speed(state, NULL); } } else retval = uart_startup(state, 1); exit: mutex_unlock(&state->mutex); return retval; } /* * uart_get_lsr_info - get line status register info. * Note: uart_ioctl protects us against hangups. */ static int uart_get_lsr_info(struct uart_state *state, unsigned int __user *value) { struct uart_port *port = state->port; unsigned int result; result = port->ops->tx_empty(port); /* * If we're about to load something into the transmit * register, we'll pretend the transmitter isn't empty to * avoid a race condition (depending on when the transmit * interrupt happens). */ if (port->x_char || ((uart_circ_chars_pending(&state->info->xmit) > 0) && !state->info->tty->stopped && !state->info->tty->hw_stopped)) result &= ~TIOCSER_TEMT; return put_user(result, value); } static int uart_tiocmget(struct tty_struct *tty, struct file *file) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; int result = -EIO; mutex_lock(&state->mutex); if ((!file || !tty_hung_up_p(file)) && !(tty->flags & (1 << TTY_IO_ERROR))) { result = port->mctrl; spin_lock_irq(&port->lock); result |= port->ops->get_mctrl(port); spin_unlock_irq(&port->lock); } mutex_unlock(&state->mutex); return result; } static int uart_tiocmset(struct tty_struct *tty, struct file *file, unsigned int set, unsigned int clear) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; int ret = -EIO; mutex_lock(&state->mutex); if ((!file || !tty_hung_up_p(file)) && !(tty->flags & (1 << TTY_IO_ERROR))) { uart_update_mctrl(port, set, clear); ret = 0; } mutex_unlock(&state->mutex); return ret; } static void uart_break_ctl(struct tty_struct *tty, int break_state) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; BUG_ON(!kernel_locked()); mutex_lock(&state->mutex); if (port->type != PORT_UNKNOWN) port->ops->break_ctl(port, break_state); mutex_unlock(&state->mutex); } static int uart_do_autoconfig(struct uart_state *state) { struct uart_port *port = state->port; int flags, ret; if (!capable(CAP_SYS_ADMIN)) return -EPERM; /* * Take the per-port semaphore. This prevents count from * changing, and hence any extra opens of the port while * we're auto-configuring. */ if (mutex_lock_interruptible(&state->mutex)) return -ERESTARTSYS; ret = -EBUSY; if (uart_users(state) == 1) { uart_shutdown(state); /* * If we already have a port type configured, * we must release its resources. */ if (port->type != PORT_UNKNOWN) port->ops->release_port(port); flags = UART_CONFIG_TYPE; if (port->flags & UPF_AUTO_IRQ) flags |= UART_CONFIG_IRQ; /* * This will claim the ports resources if * a port is found. */ port->ops->config_port(port, flags); ret = uart_startup(state, 1); } mutex_unlock(&state->mutex); return ret; } /* * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change * - mask passed in arg for lines of interest * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking) * Caller should use TIOCGICOUNT to see which one it was */ static int uart_wait_modem_status(struct uart_state *state, unsigned long arg) { struct uart_port *port = state->port; DECLARE_WAITQUEUE(wait, current); struct uart_icount cprev, cnow; int ret; /* * note the counters on entry */ spin_lock_irq(&port->lock); memcpy(&cprev, &port->icount, sizeof(struct uart_icount)); /* * Force modem status interrupts on */ port->ops->enable_ms(port); spin_unlock_irq(&port->lock); add_wait_queue(&state->info->delta_msr_wait, &wait); for (;;) { spin_lock_irq(&port->lock); memcpy(&cnow, &port->icount, sizeof(struct uart_icount)); spin_unlock_irq(&port->lock); set_current_state(TASK_INTERRUPTIBLE); if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) || ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) || ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) || ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) { ret = 0; break; } schedule(); /* see if a signal did it */ if (signal_pending(current)) { ret = -ERESTARTSYS; break; } cprev = cnow; } current->state = TASK_RUNNING; remove_wait_queue(&state->info->delta_msr_wait, &wait); return ret; } /* * Get counter of input serial line interrupts (DCD,RI,DSR,CTS) * Return: write counters to the user passed counter struct * NB: both 1->0 and 0->1 transitions are counted except for * RI where only 0->1 is counted. */ static int uart_get_count(struct uart_state *state, struct serial_icounter_struct __user *icnt) { struct serial_icounter_struct icount; struct uart_icount cnow; struct uart_port *port = state->port; spin_lock_irq(&port->lock); memcpy(&cnow, &port->icount, sizeof(struct uart_icount)); spin_unlock_irq(&port->lock); icount.cts = cnow.cts; icount.dsr = cnow.dsr; icount.rng = cnow.rng; icount.dcd = cnow.dcd; icount.rx = cnow.rx; icount.tx = cnow.tx; icount.frame = cnow.frame; icount.overrun = cnow.overrun; icount.parity = cnow.parity; icount.brk = cnow.brk; icount.buf_overrun = cnow.buf_overrun; return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0; } /* * Called via sys_ioctl under the BKL. We can use spin_lock_irq() here. */ static int uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, unsigned long arg) { struct uart_state *state = tty->driver_data; void __user *uarg = (void __user *)arg; int ret = -ENOIOCTLCMD; BUG_ON(!kernel_locked()); /* * These ioctls don't rely on the hardware to be present. */ switch (cmd) { case TIOCGSERIAL: ret = uart_get_info(state, uarg); break; case TIOCSSERIAL: ret = uart_set_info(state, uarg); break; case TIOCSERCONFIG: ret = uart_do_autoconfig(state); break; case TIOCSERGWILD: /* obsolete */ case TIOCSERSWILD: /* obsolete */ ret = 0; break; } if (ret != -ENOIOCTLCMD) goto out; if (tty->flags & (1 << TTY_IO_ERROR)) { ret = -EIO; goto out; } /* * The following should only be used when hardware is present. */ switch (cmd) { case TIOCMIWAIT: ret = uart_wait_modem_status(state, arg); break; case TIOCGICOUNT: ret = uart_get_count(state, uarg); break; } if (ret != -ENOIOCTLCMD) goto out; mutex_lock(&state->mutex); if (tty_hung_up_p(filp)) { ret = -EIO; goto out_up; } /* * All these rely on hardware being present and need to be * protected against the tty being hung up. */ switch (cmd) { case TIOCSERGETLSR: /* Get line status register */ ret = uart_get_lsr_info(state, uarg); break; default: { struct uart_port *port = state->port; if (port->ops->ioctl) ret = port->ops->ioctl(port, cmd, arg); break; } } out_up: mutex_unlock(&state->mutex); out: return ret; } static void uart_set_termios(struct tty_struct *tty, struct ktermios *old_termios) { struct uart_state *state = tty->driver_data; unsigned long flags; unsigned int cflag = tty->termios->c_cflag; BUG_ON(!kernel_locked()); /* * These are the bits that are used to setup various * flags in the low level driver. We can ignore the Bfoo * bits in c_cflag; c_[io]speed will always be set * appropriately by set_termios() in tty_ioctl.c */ #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK)) if ((cflag ^ old_termios->c_cflag) == 0 && tty->termios->c_ospeed == old_termios->c_ospeed && tty->termios->c_ispeed == old_termios->c_ispeed && RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) return; uart_change_speed(state, old_termios); /* Handle transition to B0 status */ if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) uart_clear_mctrl(state->port, TIOCM_RTS | TIOCM_DTR); /* Handle transition away from B0 status */ if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) { unsigned int mask = TIOCM_DTR; if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags)) mask |= TIOCM_RTS; uart_set_mctrl(state->port, mask); } /* Handle turning off CRTSCTS */ if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) { spin_lock_irqsave(&state->port->lock, flags); tty->hw_stopped = 0; __uart_start(tty); spin_unlock_irqrestore(&state->port->lock, flags); } /* Handle turning on CRTSCTS */ if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) { spin_lock_irqsave(&state->port->lock, flags); if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) { tty->hw_stopped = 1; state->port->ops->stop_tx(state->port); } spin_unlock_irqrestore(&state->port->lock, flags); } #if 0 /* * No need to wake up processes in open wait, since they * sample the CLOCAL flag once, and don't recheck it. * XXX It's not clear whether the current behavior is correct * or not. Hence, this may change..... */ if (!(old_termios->c_cflag & CLOCAL) && (tty->termios->c_cflag & CLOCAL)) wake_up_interruptible(&state->info->open_wait); #endif } /* * In 2.4.5, calls to this will be serialized via the BKL in * linux/drivers/char/tty_io.c:tty_release() * linux/drivers/char/tty_io.c:do_tty_handup() */ static void uart_close(struct tty_struct *tty, struct file *filp) { struct uart_state *state = tty->driver_data; struct uart_port *port; BUG_ON(!kernel_locked()); if (!state || !state->port) return; port = state->port; pr_debug("uart_close(%d) called\n", port->line); mutex_lock(&state->mutex); if (tty_hung_up_p(filp)) goto done; if ((tty->count == 1) && (state->count != 1)) { /* * Uh, oh. tty->count is 1, which means that the tty * structure will be freed. state->count should always * be one in these conditions. If it's greater than * one, we've got real problems, since it means the * serial port won't be shutdown. */ printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, " "state->count is %d\n", state->count); state->count = 1; } if (--state->count < 0) { printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n", tty->name, state->count); state->count = 0; } if (state->count) goto done; /* * Now we wait for the transmit buffer to clear; and we notify * the line discipline to only process XON/XOFF characters by * setting tty->closing. */ tty->closing = 1; if (state->closing_wait != USF_CLOSING_WAIT_NONE) tty_wait_until_sent(tty, msecs_to_jiffies(state->closing_wait)); /* * At this point, we stop accepting input. To do this, we * disable the receive line status interrupts. */ if (state->info->flags & UIF_INITIALIZED) { unsigned long flags; spin_lock_irqsave(&port->lock, flags); port->ops->stop_rx(port); spin_unlock_irqrestore(&port->lock, flags); /* * Before we drop DTR, make sure the UART transmitter * has completely drained; this is especially * important if there is a transmit FIFO! */ uart_wait_until_sent(tty, port->timeout); } uart_shutdown(state); uart_flush_buffer(tty); tty_ldisc_flush(tty); tty->closing = 0; state->info->tty = NULL; if (state->info->blocked_open) { if (state->close_delay) msleep_interruptible(state->close_delay); } else if (!uart_console(port)) { uart_change_pm(state, 3); } /* * Wake up anyone trying to open this port. */ state->info->flags &= ~UIF_NORMAL_ACTIVE; wake_up_interruptible(&state->info->open_wait); done: mutex_unlock(&state->mutex); } static void uart_wait_until_sent(struct tty_struct *tty, int timeout) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; unsigned long char_time, expire; BUG_ON(!kernel_locked()); if (port->type == PORT_UNKNOWN || port->fifosize == 0) return; /* * Set the check interval to be 1/5 of the estimated time to * send a single character, and make it at least 1. The check * interval should also be less than the timeout. * * Note: we have to use pretty tight timings here to satisfy * the NIST-PCTS. */ char_time = (port->timeout - HZ/50) / port->fifosize; char_time = char_time / 5; if (char_time == 0) char_time = 1; if (timeout && timeout < char_time) char_time = timeout; /* * If the transmitter hasn't cleared in twice the approximate * amount of time to send the entire FIFO, it probably won't * ever clear. This assumes the UART isn't doing flow * control, which is currently the case. Hence, if it ever * takes longer than port->timeout, this is probably due to a * UART bug of some kind. So, we clamp the timeout parameter at * 2*port->timeout. */ if (timeout == 0 || timeout > 2 * port->timeout) timeout = 2 * port->timeout; expire = jiffies + timeout; pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n", port->line, jiffies, expire); /* * Check whether the transmitter is empty every 'char_time'. * 'timeout' / 'expire' give us the maximum amount of time * we wait. */ while (!port->ops->tx_empty(port)) { msleep_interruptible(jiffies_to_msecs(char_time)); if (signal_pending(current)) break; if (time_after(jiffies, expire)) break; } set_current_state(TASK_RUNNING); /* might not be needed */ } /* * This is called with the BKL held in * linux/drivers/char/tty_io.c:do_tty_hangup() * We're called from the eventd thread, so we can sleep for * a _short_ time only. */ static void uart_hangup(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; BUG_ON(!kernel_locked()); pr_debug("uart_hangup(%d)\n", state->port->line); mutex_lock(&state->mutex); if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) { uart_flush_buffer(tty); uart_shutdown(state); state->count = 0; state->info->flags &= ~UIF_NORMAL_ACTIVE; state->info->tty = NULL; wake_up_interruptible(&state->info->open_wait); wake_up_interruptible(&state->info->delta_msr_wait); } mutex_unlock(&state->mutex); } /* * Copy across the serial console cflag setting into the termios settings * for the initial open of the port. This allows continuity between the * kernel settings, and the settings init adopts when it opens the port * for the first time. */ static void uart_update_termios(struct uart_state *state) { struct tty_struct *tty = state->info->tty; struct uart_port *port = state->port; if (uart_console(port) && port->cons->cflag) { tty->termios->c_cflag = port->cons->cflag; port->cons->cflag = 0; } /* * If the device failed to grab its irq resources, * or some other error occurred, don't try to talk * to the port hardware. */ if (!(tty->flags & (1 << TTY_IO_ERROR))) { /* * Make termios settings take effect. */ uart_change_speed(state, NULL); /* * And finally enable the RTS and DTR signals. */ if (tty->termios->c_cflag & CBAUD) uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS); } } /* * Block the open until the port is ready. We must be called with * the per-port semaphore held. */ static int uart_block_til_ready(struct file *filp, struct uart_state *state) { DECLARE_WAITQUEUE(wait, current); struct uart_info *info = state->info; struct uart_port *port = state->port; unsigned int mctrl; info->blocked_open++; state->count--; add_wait_queue(&info->open_wait, &wait); while (1) { set_current_state(TASK_INTERRUPTIBLE); /* * If we have been hung up, tell userspace/restart open. */ if (tty_hung_up_p(filp) || info->tty == NULL) break; /* * If the port has been closed, tell userspace/restart open. */ if (!(info->flags & UIF_INITIALIZED)) break; /* * If non-blocking mode is set, or CLOCAL mode is set, * we don't want to wait for the modem status lines to * indicate that the port is ready. * * Also, if the port is not enabled/configured, we want * to allow the open to succeed here. Note that we will * have set TTY_IO_ERROR for a non-existant port. */ if ((filp->f_flags & O_NONBLOCK) || (info->tty->termios->c_cflag & CLOCAL) || (info->tty->flags & (1 << TTY_IO_ERROR))) { break; } /* * Set DTR to allow modem to know we're waiting. Do * not set RTS here - we want to make sure we catch * the data from the modem. */ if (info->tty->termios->c_cflag & CBAUD) uart_set_mctrl(port, TIOCM_DTR); /* * and wait for the carrier to indicate that the * modem is ready for us. */ spin_lock_irq(&port->lock); port->ops->enable_ms(port); mctrl = port->ops->get_mctrl(port); spin_unlock_irq(&port->lock); if (mctrl & TIOCM_CAR) break; mutex_unlock(&state->mutex); schedule(); mutex_lock(&state->mutex); if (signal_pending(current)) break; } set_current_state(TASK_RUNNING); remove_wait_queue(&info->open_wait, &wait); state->count++; info->blocked_open--; if (signal_pending(current)) return -ERESTARTSYS; if (!info->tty || tty_hung_up_p(filp)) return -EAGAIN; return 0; } static struct uart_state *uart_get(struct uart_driver *drv, int line) { struct uart_state *state; int ret = 0; state = drv->state + line; if (mutex_lock_interruptible(&state->mutex)) { ret = -ERESTARTSYS; goto err; } state->count++; if (!state->port || state->port->flags & UPF_DEAD) { ret = -ENXIO; goto err_unlock; } if (!state->info) { state->info = kzalloc(sizeof(struct uart_info), GFP_KERNEL); if (state->info) { init_waitqueue_head(&state->info->open_wait); init_waitqueue_head(&state->info->delta_msr_wait); /* * Link the info into the other structures. */ state->port->info = state->info; tasklet_init(&state->info->tlet, uart_tasklet_action, (unsigned long)state); } else { ret = -ENOMEM; goto err_unlock; } } return state; err_unlock: state->count--; mutex_unlock(&state->mutex); err: return ERR_PTR(ret); } /* * In 2.4.5, calls to uart_open are serialised by the BKL in * linux/fs/devices.c:chrdev_open() * Note that if this fails, then uart_close() _will_ be called. * * In time, we want to scrap the "opening nonpresent ports" * behaviour and implement an alternative way for setserial * to set base addresses/ports/types. This will allow us to * get rid of a certain amount of extra tests. */ static int uart_open(struct tty_struct *tty, struct file *filp) { struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state; struct uart_state *state; int retval, line = tty->index; BUG_ON(!kernel_locked()); pr_debug("uart_open(%d) called\n", line); /* * tty->driver->num won't change, so we won't fail here with * tty->driver_data set to something non-NULL (and therefore * we won't get caught by uart_close()). */ retval = -ENODEV; if (line >= tty->driver->num) goto fail; /* * We take the semaphore inside uart_get to guarantee that we won't * be re-entered while allocating the info structure, or while we * request any IRQs that the driver may need. This also has the nice * side-effect that it delays the action of uart_hangup, so we can * guarantee that info->tty will always contain something reasonable. */ state = uart_get(drv, line); if (IS_ERR(state)) { retval = PTR_ERR(state); goto fail; } /* * Once we set tty->driver_data here, we are guaranteed that * uart_close() will decrement the driver module use count. * Any failures from here onwards should not touch the count. */ tty->driver_data = state; tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0; tty->alt_speed = 0; state->info->tty = tty; /* * If the port is in the middle of closing, bail out now. */ if (tty_hung_up_p(filp)) { retval = -EAGAIN; state->count--; mutex_unlock(&state->mutex); goto fail; } /* * Make sure the device is in D0 state. */ if (state->count == 1) uart_change_pm(state, 0); /* * Start up the serial port. */ retval = uart_startup(state, 0); /* * If we succeeded, wait until the port is ready. */ if (retval == 0) retval = uart_block_til_ready(filp, state); mutex_unlock(&state->mutex); /* * If this is the first open to succeed, adjust things to suit. */ if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) { state->info->flags |= UIF_NORMAL_ACTIVE; uart_update_termios(state); } fail: return retval; } static const char *uart_type(struct uart_port *port) { const char *str = NULL; if (port->ops->type) str = port->ops->type(port); if (!str) str = "unknown"; return str; } #ifdef CONFIG_PROC_FS static int uart_line_info(char *buf, struct uart_driver *drv, int i) { struct uart_state *state = drv->state + i; int pm_state; struct uart_port *port = state->port; char stat_buf[32]; unsigned int status; int mmio, ret; if (!port) return 0; mmio = port->iotype >= UPIO_MEM; ret = sprintf(buf, "%d: uart:%s %s%08llX irq:%d", port->line, uart_type(port), mmio ? "mmio:0x" : "port:", mmio ? (unsigned long long)port->mapbase : (unsigned long long) port->iobase, port->irq); if (port->type == PORT_UNKNOWN) { strcat(buf, "\n"); return ret + 1; } if(capable(CAP_SYS_ADMIN)) { mutex_lock(&state->mutex); pm_state = state->pm_state; if (pm_state) uart_change_pm(state, 0); spin_lock_irq(&port->lock); status = port->ops->get_mctrl(port); spin_unlock_irq(&port->lock); if (pm_state) uart_change_pm(state, pm_state); mutex_unlock(&state->mutex); ret += sprintf(buf + ret, " tx:%d rx:%d", port->icount.tx, port->icount.rx); if (port->icount.frame) ret += sprintf(buf + ret, " fe:%d", port->icount.frame); if (port->icount.parity) ret += sprintf(buf + ret, " pe:%d", port->icount.parity); if (port->icount.brk) ret += sprintf(buf + ret, " brk:%d", port->icount.brk); if (port->icount.overrun) ret += sprintf(buf + ret, " oe:%d", port->icount.overrun); #define INFOBIT(bit,str) \ if (port->mctrl & (bit)) \ strncat(stat_buf, (str), sizeof(stat_buf) - \ strlen(stat_buf) - 2) #define STATBIT(bit,str) \ if (status & (bit)) \ strncat(stat_buf, (str), sizeof(stat_buf) - \ strlen(stat_buf) - 2) stat_buf[0] = '\0'; stat_buf[1] = '\0'; INFOBIT(TIOCM_RTS, "|RTS"); STATBIT(TIOCM_CTS, "|CTS"); INFOBIT(TIOCM_DTR, "|DTR"); STATBIT(TIOCM_DSR, "|DSR"); STATBIT(TIOCM_CAR, "|CD"); STATBIT(TIOCM_RNG, "|RI"); if (stat_buf[0]) stat_buf[0] = ' '; strcat(stat_buf, "\n"); ret += sprintf(buf + ret, stat_buf); } else { strcat(buf, "\n"); ret++; } #undef STATBIT #undef INFOBIT return ret; } static int uart_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data) { struct tty_driver *ttydrv = data; struct uart_driver *drv = ttydrv->driver_state; int i, len = 0, l; off_t begin = 0; len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n", "", "", ""); for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) { l = uart_line_info(page + len, drv, i); len += l; if (len + begin > off + count) goto done; if (len + begin < off) { begin += len; len = 0; } } *eof = 1; done: if (off >= len + begin) return 0; *start = page + (off - begin); return (count < begin + len - off) ? count : (begin + len - off); } #endif #ifdef CONFIG_SERIAL_CORE_CONSOLE /* * uart_console_write - write a console message to a serial port * @port: the port to write the message * @s: array of characters * @count: number of characters in string to write * @write: function to write character to port */ void uart_console_write(struct uart_port *port, const char *s, unsigned int count, void (*putchar)(struct uart_port *, int)) { unsigned int i; for (i = 0; i < count; i++, s++) { if (*s == '\n') putchar(port, '\r'); putchar(port, *s); } } EXPORT_SYMBOL_GPL(uart_console_write); /* * Check whether an invalid uart number has been specified, and * if so, search for the first available port that does have * console support. */ struct uart_port * __init uart_get_console(struct uart_port *ports, int nr, struct console *co) { int idx = co->index; if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 && ports[idx].membase == NULL)) for (idx = 0; idx < nr; idx++) if (ports[idx].iobase != 0 || ports[idx].membase != NULL) break; co->index = idx; return ports + idx; } /** * uart_parse_options - Parse serial port baud/parity/bits/flow contro. * @options: pointer to option string * @baud: pointer to an 'int' variable for the baud rate. * @parity: pointer to an 'int' variable for the parity. * @bits: pointer to an 'int' variable for the number of data bits. * @flow: pointer to an 'int' variable for the flow control character. * * uart_parse_options decodes a string containing the serial console * options. The format of the string is , * eg: 115200n8r */ void __init uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow) { char *s = options; *baud = simple_strtoul(s, NULL, 10); while (*s >= '0' && *s <= '9') s++; if (*s) *parity = *s++; if (*s) *bits = *s++ - '0'; if (*s) *flow = *s; } struct baud_rates { unsigned int rate; unsigned int cflag; }; static const struct baud_rates baud_rates[] = { { 921600, B921600 }, { 460800, B460800 }, { 230400, B230400 }, { 115200, B115200 }, { 57600, B57600 }, { 38400, B38400 }, { 19200, B19200 }, { 9600, B9600 }, { 4800, B4800 }, { 2400, B2400 }, { 1200, B1200 }, { 0, B38400 } }; /** * uart_set_options - setup the serial console parameters * @port: pointer to the serial ports uart_port structure * @co: console pointer * @baud: baud rate * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even) * @bits: number of data bits * @flow: flow control character - 'r' (rts) */ int __init uart_set_options(struct uart_port *port, struct console *co, int baud, int parity, int bits, int flow) { struct ktermios termios; int i; /* * Ensure that the serial console lock is initialised * early. */ spin_lock_init(&port->lock); lockdep_set_class(&port->lock, &port_lock_key); memset(&termios, 0, sizeof(struct ktermios)); termios.c_cflag = CREAD | HUPCL | CLOCAL; /* * Construct a cflag setting. */ for (i = 0; baud_rates[i].rate; i++) if (baud_rates[i].rate <= baud) break; termios.c_cflag |= baud_rates[i].cflag; if (bits == 7) termios.c_cflag |= CS7; else termios.c_cflag |= CS8; switch (parity) { case 'o': case 'O': termios.c_cflag |= PARODD; /*fall through*/ case 'e': case 'E': termios.c_cflag |= PARENB; break; } if (flow == 'r') termios.c_cflag |= CRTSCTS; /* * some uarts on other side don't support no flow control. * So we set * DTR in host uart to make them happy */ port->mctrl |= TIOCM_DTR; port->ops->set_termios(port, &termios, NULL); co->cflag = termios.c_cflag; return 0; } #endif /* CONFIG_SERIAL_CORE_CONSOLE */ static void uart_change_pm(struct uart_state *state, int pm_state) { struct uart_port *port = state->port; if (state->pm_state != pm_state) { if (port->ops->pm) port->ops->pm(port, pm_state, state->pm_state); state->pm_state = pm_state; } } int uart_suspend_port(struct uart_driver *drv, struct uart_port *port) { struct uart_state *state = drv->state + port->line; mutex_lock(&state->mutex); #ifdef CONFIG_DISABLE_CONSOLE_SUSPEND if (uart_console(port)) { mutex_unlock(&state->mutex); return 0; } #endif if (state->info && state->info->flags & UIF_INITIALIZED) { const struct uart_ops *ops = port->ops; state->info->flags = (state->info->flags & ~UIF_INITIALIZED) | UIF_SUSPENDED; spin_lock_irq(&port->lock); ops->stop_tx(port); ops->set_mctrl(port, 0); ops->stop_rx(port); spin_unlock_irq(&port->lock); /* * Wait for the transmitter to empty. */ while (!ops->tx_empty(port)) { msleep(10); } ops->shutdown(port); } /* * Disable the console device before suspending. */ if (uart_console(port)) console_stop(port->cons); uart_change_pm(state, 3); mutex_unlock(&state->mutex); return 0; } int uart_resume_port(struct uart_driver *drv, struct uart_port *port) { struct uart_state *state = drv->state + port->line; mutex_lock(&state->mutex); #ifdef CONFIG_DISABLE_CONSOLE_SUSPEND if (uart_console(port)) { mutex_unlock(&state->mutex); return 0; } #endif uart_change_pm(state, 0); /* * Re-enable the console device after suspending. */ if (uart_console(port)) { struct ktermios termios; /* * First try to use the console cflag setting. */ memset(&termios, 0, sizeof(struct ktermios)); termios.c_cflag = port->cons->cflag; /* * If that's unset, use the tty termios setting. */ if (state->info && state->info->tty && termios.c_cflag == 0) termios = *state->info->tty->termios; port->ops->set_termios(port, &termios, NULL); console_start(port->cons); } if (state->info && state->info->flags & UIF_SUSPENDED) { const struct uart_ops *ops = port->ops; int ret; ops->set_mctrl(port, 0); ret = ops->startup(port); if (ret == 0) { uart_change_speed(state, NULL); spin_lock_irq(&port->lock); ops->set_mctrl(port, port->mctrl); ops->start_tx(port); spin_unlock_irq(&port->lock); state->info->flags |= UIF_INITIALIZED; } else { /* * Failed to resume - maybe hardware went away? * Clear the "initialized" flag so we won't try * to call the low level drivers shutdown method. */ uart_shutdown(state); } state->info->flags &= ~UIF_SUSPENDED; } mutex_unlock(&state->mutex); return 0; } static inline void uart_report_port(struct uart_driver *drv, struct uart_port *port) { char address[64]; switch (port->iotype) { case UPIO_PORT: snprintf(address, sizeof(address), "I/O 0x%x", port->iobase); break; case UPIO_HUB6: snprintf(address, sizeof(address), "I/O 0x%x offset 0x%x", port->iobase, port->hub6); break; case UPIO_MEM: case UPIO_MEM32: case UPIO_AU: case UPIO_TSI: case UPIO_DWAPB: snprintf(address, sizeof(address), "MMIO 0x%llx", (unsigned long long)port->mapbase); break; default: strlcpy(address, "*unknown*", sizeof(address)); break; } printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n", port->dev ? port->dev->bus_id : "", port->dev ? ": " : "", drv->dev_name, port->line, address, port->irq, uart_type(port)); } static void uart_configure_port(struct uart_driver *drv, struct uart_state *state, struct uart_port *port) { unsigned int flags; /* * If there isn't a port here, don't do anything further. */ if (!port->iobase && !port->mapbase && !port->membase) return; /* * Now do the auto configuration stuff. Note that config_port * is expected to claim the resources and map the port for us. */ flags = UART_CONFIG_TYPE; if (port->flags & UPF_AUTO_IRQ) flags |= UART_CONFIG_IRQ; if (port->flags & UPF_BOOT_AUTOCONF) { port->type = PORT_UNKNOWN; port->ops->config_port(port, flags); } if (port->type != PORT_UNKNOWN) { unsigned long flags; uart_report_port(drv, port); /* Power up port for set_mctrl() */ uart_change_pm(state, 0); /* * Ensure that the modem control lines are de-activated. * We probably don't need a spinlock around this, but */ spin_lock_irqsave(&port->lock, flags); port->ops->set_mctrl(port, 0); spin_unlock_irqrestore(&port->lock, flags); /* * Power down all ports by default, except the * console if we have one. */ if (!uart_console(port)) uart_change_pm(state, 3); } } static const struct tty_operations uart_ops = { .open = uart_open, .close = uart_close, .write = uart_write, .put_char = uart_put_char, .flush_chars = uart_flush_chars, .write_room = uart_write_room, .chars_in_buffer= uart_chars_in_buffer, .flush_buffer = uart_flush_buffer, .ioctl = uart_ioctl, .throttle = uart_throttle, .unthrottle = uart_unthrottle, .send_xchar = uart_send_xchar, .set_termios = uart_set_termios, .stop = uart_stop, .start = uart_start, .hangup = uart_hangup, .break_ctl = uart_break_ctl, .wait_until_sent= uart_wait_until_sent, #ifdef CONFIG_PROC_FS .read_proc = uart_read_proc, #endif .tiocmget = uart_tiocmget, .tiocmset = uart_tiocmset, }; /** * uart_register_driver - register a driver with the uart core layer * @drv: low level driver structure * * Register a uart driver with the core driver. We in turn register * with the tty layer, and initialise the core driver per-port state. * * We have a proc file in /proc/tty/driver which is named after the * normal driver. * * drv->port should be NULL, and the per-port structures should be * registered using uart_add_one_port after this call has succeeded. */ int uart_register_driver(struct uart_driver *drv) { struct tty_driver *normal = NULL; int i, retval; BUG_ON(drv->state); /* * Maybe we should be using a slab cache for this, especially if * we have a large number of ports to handle. */ drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL); retval = -ENOMEM; if (!drv->state) goto out; normal = alloc_tty_driver(drv->nr); if (!normal) goto out; drv->tty_driver = normal; normal->owner = drv->owner; normal->driver_name = drv->driver_name; normal->name = drv->dev_name; normal->major = drv->major; normal->minor_start = drv->minor; normal->type = TTY_DRIVER_TYPE_SERIAL; normal->subtype = SERIAL_TYPE_NORMAL; normal->init_termios = tty_std_termios; normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL; normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600; normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; normal->driver_state = drv; tty_set_operations(normal, &uart_ops); /* * Initialise the UART state(s). */ for (i = 0; i < drv->nr; i++) { struct uart_state *state = drv->state + i; state->close_delay = 500; /* .5 seconds */ state->closing_wait = 30000; /* 30 seconds */ mutex_init(&state->mutex); } retval = tty_register_driver(normal); out: if (retval < 0) { put_tty_driver(normal); kfree(drv->state); } return retval; } /** * uart_unregister_driver - remove a driver from the uart core layer * @drv: low level driver structure * * Remove all references to a driver from the core driver. The low * level driver must have removed all its ports via the * uart_remove_one_port() if it registered them with uart_add_one_port(). * (ie, drv->port == NULL) */ void uart_unregister_driver(struct uart_driver *drv) { struct tty_driver *p = drv->tty_driver; tty_unregister_driver(p); put_tty_driver(p); kfree(drv->state); drv->tty_driver = NULL; } struct tty_driver *uart_console_device(struct console *co, int *index) { struct uart_driver *p = co->data; *index = co->index; return p->tty_driver; } /** * uart_add_one_port - attach a driver-defined port structure * @drv: pointer to the uart low level driver structure for this port * @port: uart port structure to use for this port. * * This allows the driver to register its own uart_port structure * with the core driver. The main purpose is to allow the low * level uart drivers to expand uart_port, rather than having yet * more levels of structures. */ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port) { struct uart_state *state; int ret = 0; BUG_ON(in_interrupt()); if (port->line >= drv->nr) return -EINVAL; state = drv->state + port->line; mutex_lock(&port_mutex); mutex_lock(&state->mutex); if (state->port) { ret = -EINVAL; goto out; } state->port = port; port->cons = drv->cons; port->info = state->info; /* * If this port is a console, then the spinlock is already * initialised. */ if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) { spin_lock_init(&port->lock); lockdep_set_class(&port->lock, &port_lock_key); } uart_configure_port(drv, state, port); /* * Register the port whether it's detected or not. This allows * setserial to be used to alter this ports parameters. */ tty_register_device(drv->tty_driver, port->line, port->dev); /* * If this driver supports console, and it hasn't been * successfully registered yet, try to re-register it. * It may be that the port was not available. */ if (port->type != PORT_UNKNOWN && port->cons && !(port->cons->flags & CON_ENABLED)) register_console(port->cons); /* * Ensure UPF_DEAD is not set. */ port->flags &= ~UPF_DEAD; out: mutex_unlock(&state->mutex); mutex_unlock(&port_mutex); return ret; } /** * uart_remove_one_port - detach a driver defined port structure * @drv: pointer to the uart low level driver structure for this port * @port: uart port structure for this port * * This unhooks (and hangs up) the specified port structure from the * core driver. No further calls will be made to the low-level code * for this port. */ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port) { struct uart_state *state = drv->state + port->line; struct uart_info *info; BUG_ON(in_interrupt()); if (state->port != port) printk(KERN_ALERT "Removing wrong port: %p != %p\n", state->port, port); mutex_lock(&port_mutex); /* * Mark the port "dead" - this prevents any opens from * succeeding while we shut down the port. */ mutex_lock(&state->mutex); port->flags |= UPF_DEAD; mutex_unlock(&state->mutex); /* * Remove the devices from the tty layer */ tty_unregister_device(drv->tty_driver, port->line); info = state->info; if (info && info->tty) tty_vhangup(info->tty); /* * All users of this port should now be disconnected from * this driver, and the port shut down. We should be the * only thread fiddling with this port from now on. */ state->info = NULL; /* * Free the port IO and memory resources, if any. */ if (port->type != PORT_UNKNOWN) port->ops->release_port(port); /* * Indicate that there isn't a port here anymore. */ port->type = PORT_UNKNOWN; /* * Kill the tasklet, and free resources. */ if (info) { tasklet_kill(&info->tlet); kfree(info); } state->port = NULL; mutex_unlock(&port_mutex); return 0; } /* * Are the two ports equivalent? */ int uart_match_port(struct uart_port *port1, struct uart_port *port2) { if (port1->iotype != port2->iotype) return 0; switch (port1->iotype) { case UPIO_PORT: return (port1->iobase == port2->iobase); case UPIO_HUB6: return (port1->iobase == port2->iobase) && (port1->hub6 == port2->hub6); case UPIO_MEM: case UPIO_MEM32: case UPIO_AU: case UPIO_TSI: case UPIO_DWAPB: return (port1->mapbase == port2->mapbase); } return 0; } EXPORT_SYMBOL(uart_match_port); EXPORT_SYMBOL(uart_write_wakeup); EXPORT_SYMBOL(uart_register_driver); EXPORT_SYMBOL(uart_unregister_driver); EXPORT_SYMBOL(uart_suspend_port); EXPORT_SYMBOL(uart_resume_port); EXPORT_SYMBOL(uart_add_one_port); EXPORT_SYMBOL(uart_remove_one_port); MODULE_DESCRIPTION("Serial driver core"); MODULE_LICENSE("GPL");