2310 lines
55 KiB
C
2310 lines
55 KiB
C
/*
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* linux/drivers/char/core.c
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*
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* Driver core for serial ports
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*
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* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
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*
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* Copyright 1999 ARM Limited
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* Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/tty.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/console.h>
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#include <linux/serial_core.h>
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#include <linux/smp_lock.h>
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#include <linux/device.h>
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#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
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#include <linux/delay.h>
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#include <asm/irq.h>
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#include <asm/uaccess.h>
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#undef DEBUG
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#ifdef DEBUG
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#define DPRINTK(x...) printk(x)
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#else
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#define DPRINTK(x...) do { } while (0)
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#endif
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/*
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* This is used to lock changes in serial line configuration.
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*/
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static DECLARE_MUTEX(port_sem);
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#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
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#define uart_users(state) ((state)->count + ((state)->info ? (state)->info->blocked_open : 0))
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#ifdef CONFIG_SERIAL_CORE_CONSOLE
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#define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
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#else
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#define uart_console(port) (0)
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#endif
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static void uart_change_speed(struct uart_state *state, struct termios *old_termios);
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static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
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static void uart_change_pm(struct uart_state *state, int pm_state);
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/*
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* This routine is used by the interrupt handler to schedule processing in
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* the software interrupt portion of the driver.
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*/
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void uart_write_wakeup(struct uart_port *port)
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{
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struct uart_info *info = port->info;
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tasklet_schedule(&info->tlet);
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}
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static void uart_stop(struct tty_struct *tty)
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{
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struct uart_state *state = tty->driver_data;
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struct uart_port *port = state->port;
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unsigned long flags;
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spin_lock_irqsave(&port->lock, flags);
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port->ops->stop_tx(port);
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spin_unlock_irqrestore(&port->lock, flags);
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}
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static void __uart_start(struct tty_struct *tty)
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{
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struct uart_state *state = tty->driver_data;
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struct uart_port *port = state->port;
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if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf &&
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!tty->stopped && !tty->hw_stopped)
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port->ops->start_tx(port);
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}
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static void uart_start(struct tty_struct *tty)
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{
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struct uart_state *state = tty->driver_data;
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struct uart_port *port = state->port;
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unsigned long flags;
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spin_lock_irqsave(&port->lock, flags);
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__uart_start(tty);
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spin_unlock_irqrestore(&port->lock, flags);
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}
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static void uart_tasklet_action(unsigned long data)
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{
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struct uart_state *state = (struct uart_state *)data;
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tty_wakeup(state->info->tty);
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}
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static inline void
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uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
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{
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unsigned long flags;
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unsigned int old;
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spin_lock_irqsave(&port->lock, flags);
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old = port->mctrl;
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port->mctrl = (old & ~clear) | set;
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if (old != port->mctrl)
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port->ops->set_mctrl(port, port->mctrl);
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spin_unlock_irqrestore(&port->lock, flags);
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}
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#define uart_set_mctrl(port,set) uart_update_mctrl(port,set,0)
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#define uart_clear_mctrl(port,clear) uart_update_mctrl(port,0,clear)
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/*
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* Startup the port. This will be called once per open. All calls
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* will be serialised by the per-port semaphore.
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*/
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static int uart_startup(struct uart_state *state, int init_hw)
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{
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struct uart_info *info = state->info;
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struct uart_port *port = state->port;
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unsigned long page;
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int retval = 0;
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if (info->flags & UIF_INITIALIZED)
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return 0;
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/*
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* Set the TTY IO error marker - we will only clear this
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* once we have successfully opened the port. Also set
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* up the tty->alt_speed kludge
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*/
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if (info->tty)
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set_bit(TTY_IO_ERROR, &info->tty->flags);
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if (port->type == PORT_UNKNOWN)
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return 0;
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/*
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* Initialise and allocate the transmit and temporary
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* buffer.
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*/
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if (!info->xmit.buf) {
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page = get_zeroed_page(GFP_KERNEL);
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if (!page)
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return -ENOMEM;
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info->xmit.buf = (unsigned char *) page;
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uart_circ_clear(&info->xmit);
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}
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retval = port->ops->startup(port);
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if (retval == 0) {
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if (init_hw) {
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/*
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* Initialise the hardware port settings.
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*/
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uart_change_speed(state, NULL);
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/*
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* Setup the RTS and DTR signals once the
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* port is open and ready to respond.
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*/
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if (info->tty->termios->c_cflag & CBAUD)
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uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
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}
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if (info->flags & UIF_CTS_FLOW) {
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spin_lock_irq(&port->lock);
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if (!(port->ops->get_mctrl(port) & TIOCM_CTS))
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info->tty->hw_stopped = 1;
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spin_unlock_irq(&port->lock);
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}
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info->flags |= UIF_INITIALIZED;
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clear_bit(TTY_IO_ERROR, &info->tty->flags);
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}
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if (retval && capable(CAP_SYS_ADMIN))
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retval = 0;
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return retval;
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}
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/*
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* This routine will shutdown a serial port; interrupts are disabled, and
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* DTR is dropped if the hangup on close termio flag is on. Calls to
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* uart_shutdown are serialised by the per-port semaphore.
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*/
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static void uart_shutdown(struct uart_state *state)
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{
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struct uart_info *info = state->info;
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struct uart_port *port = state->port;
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if (!(info->flags & UIF_INITIALIZED))
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return;
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/*
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* Turn off DTR and RTS early.
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*/
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if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
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uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
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/*
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* clear delta_msr_wait queue to avoid mem leaks: we may free
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* the irq here so the queue might never be woken up. Note
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* that we won't end up waiting on delta_msr_wait again since
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* any outstanding file descriptors should be pointing at
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* hung_up_tty_fops now.
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*/
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wake_up_interruptible(&info->delta_msr_wait);
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/*
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* Free the IRQ and disable the port.
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*/
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port->ops->shutdown(port);
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/*
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* Ensure that the IRQ handler isn't running on another CPU.
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*/
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synchronize_irq(port->irq);
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/*
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* Free the transmit buffer page.
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*/
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if (info->xmit.buf) {
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free_page((unsigned long)info->xmit.buf);
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info->xmit.buf = NULL;
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}
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/*
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* kill off our tasklet
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*/
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tasklet_kill(&info->tlet);
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if (info->tty)
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set_bit(TTY_IO_ERROR, &info->tty->flags);
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info->flags &= ~UIF_INITIALIZED;
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}
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/**
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* uart_update_timeout - update per-port FIFO timeout.
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* @port: uart_port structure describing the port
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* @cflag: termios cflag value
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* @baud: speed of the port
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*
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* Set the port FIFO timeout value. The @cflag value should
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* reflect the actual hardware settings.
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*/
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void
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uart_update_timeout(struct uart_port *port, unsigned int cflag,
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unsigned int baud)
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{
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unsigned int bits;
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/* byte size and parity */
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switch (cflag & CSIZE) {
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case CS5:
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bits = 7;
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break;
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case CS6:
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bits = 8;
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break;
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case CS7:
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bits = 9;
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break;
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default:
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bits = 10;
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break; // CS8
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}
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if (cflag & CSTOPB)
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bits++;
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if (cflag & PARENB)
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bits++;
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/*
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* The total number of bits to be transmitted in the fifo.
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*/
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bits = bits * port->fifosize;
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/*
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* Figure the timeout to send the above number of bits.
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* Add .02 seconds of slop
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*/
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port->timeout = (HZ * bits) / baud + HZ/50;
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}
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EXPORT_SYMBOL(uart_update_timeout);
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/**
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* uart_get_baud_rate - return baud rate for a particular port
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* @port: uart_port structure describing the port in question.
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* @termios: desired termios settings.
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* @old: old termios (or NULL)
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* @min: minimum acceptable baud rate
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* @max: maximum acceptable baud rate
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*
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* Decode the termios structure into a numeric baud rate,
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* taking account of the magic 38400 baud rate (with spd_*
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* flags), and mapping the %B0 rate to 9600 baud.
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*
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* If the new baud rate is invalid, try the old termios setting.
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* If it's still invalid, we try 9600 baud.
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*
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* Update the @termios structure to reflect the baud rate
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* we're actually going to be using.
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*/
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unsigned int
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uart_get_baud_rate(struct uart_port *port, struct termios *termios,
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struct termios *old, unsigned int min, unsigned int max)
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{
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unsigned int try, baud, altbaud = 38400;
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unsigned int flags = port->flags & UPF_SPD_MASK;
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if (flags == UPF_SPD_HI)
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altbaud = 57600;
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if (flags == UPF_SPD_VHI)
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altbaud = 115200;
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if (flags == UPF_SPD_SHI)
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altbaud = 230400;
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if (flags == UPF_SPD_WARP)
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altbaud = 460800;
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for (try = 0; try < 2; try++) {
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baud = tty_termios_baud_rate(termios);
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/*
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* The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
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* Die! Die! Die!
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*/
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if (baud == 38400)
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baud = altbaud;
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/*
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* Special case: B0 rate.
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*/
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if (baud == 0)
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baud = 9600;
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if (baud >= min && baud <= max)
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return baud;
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/*
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* Oops, the quotient was zero. Try again with
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* the old baud rate if possible.
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*/
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termios->c_cflag &= ~CBAUD;
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if (old) {
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termios->c_cflag |= old->c_cflag & CBAUD;
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old = NULL;
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continue;
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}
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/*
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* As a last resort, if the quotient is zero,
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* default to 9600 bps
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*/
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termios->c_cflag |= B9600;
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}
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return 0;
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}
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EXPORT_SYMBOL(uart_get_baud_rate);
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/**
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* uart_get_divisor - return uart clock divisor
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* @port: uart_port structure describing the port.
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* @baud: desired baud rate
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*
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* Calculate the uart clock divisor for the port.
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*/
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unsigned int
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uart_get_divisor(struct uart_port *port, unsigned int baud)
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{
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unsigned int quot;
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/*
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* Old custom speed handling.
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*/
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if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
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quot = port->custom_divisor;
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else
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quot = (port->uartclk + (8 * baud)) / (16 * baud);
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return quot;
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}
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EXPORT_SYMBOL(uart_get_divisor);
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static void
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uart_change_speed(struct uart_state *state, struct termios *old_termios)
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{
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struct tty_struct *tty = state->info->tty;
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struct uart_port *port = state->port;
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struct termios *termios;
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/*
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* If we have no tty, termios, or the port does not exist,
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* then we can't set the parameters for this port.
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*/
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if (!tty || !tty->termios || port->type == PORT_UNKNOWN)
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return;
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termios = tty->termios;
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/*
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* Set flags based on termios cflag
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*/
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if (termios->c_cflag & CRTSCTS)
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state->info->flags |= UIF_CTS_FLOW;
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else
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state->info->flags &= ~UIF_CTS_FLOW;
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if (termios->c_cflag & CLOCAL)
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state->info->flags &= ~UIF_CHECK_CD;
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else
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state->info->flags |= UIF_CHECK_CD;
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port->ops->set_termios(port, termios, old_termios);
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}
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static inline void
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__uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
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{
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unsigned long flags;
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if (!circ->buf)
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return;
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spin_lock_irqsave(&port->lock, flags);
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if (uart_circ_chars_free(circ) != 0) {
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circ->buf[circ->head] = c;
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circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
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}
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spin_unlock_irqrestore(&port->lock, flags);
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}
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static void uart_put_char(struct tty_struct *tty, unsigned char ch)
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{
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struct uart_state *state = tty->driver_data;
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__uart_put_char(state->port, &state->info->xmit, ch);
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}
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static void uart_flush_chars(struct tty_struct *tty)
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{
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uart_start(tty);
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}
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static int
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uart_write(struct tty_struct *tty, const unsigned char * buf, int count)
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{
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struct uart_state *state = tty->driver_data;
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struct uart_port *port = state->port;
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struct circ_buf *circ = &state->info->xmit;
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unsigned long flags;
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int c, ret = 0;
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if (!circ->buf)
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return 0;
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spin_lock_irqsave(&port->lock, flags);
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while (1) {
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c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
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if (count < c)
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c = count;
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if (c <= 0)
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break;
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memcpy(circ->buf + circ->head, buf, c);
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circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
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buf += c;
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count -= c;
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ret += c;
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}
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spin_unlock_irqrestore(&port->lock, flags);
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uart_start(tty);
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return ret;
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}
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static int uart_write_room(struct tty_struct *tty)
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{
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struct uart_state *state = tty->driver_data;
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return uart_circ_chars_free(&state->info->xmit);
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}
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static int uart_chars_in_buffer(struct tty_struct *tty)
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{
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struct uart_state *state = tty->driver_data;
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return uart_circ_chars_pending(&state->info->xmit);
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}
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static void uart_flush_buffer(struct tty_struct *tty)
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{
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struct uart_state *state = tty->driver_data;
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struct uart_port *port = state->port;
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unsigned long flags;
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DPRINTK("uart_flush_buffer(%d) called\n", tty->index);
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spin_lock_irqsave(&port->lock, flags);
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uart_circ_clear(&state->info->xmit);
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spin_unlock_irqrestore(&port->lock, flags);
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tty_wakeup(tty);
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}
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/*
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* This function is used to send a high-priority XON/XOFF character to
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* the device
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*/
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static void uart_send_xchar(struct tty_struct *tty, char ch)
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{
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struct uart_state *state = tty->driver_data;
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struct uart_port *port = state->port;
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unsigned long flags;
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if (port->ops->send_xchar)
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port->ops->send_xchar(port, ch);
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else {
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port->x_char = ch;
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|
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 *)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, old_flags, closing_wait;
|
|
unsigned int old_custom_divisor, close_delay;
|
|
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.
|
|
*/
|
|
down(&state->sem);
|
|
|
|
change_irq = 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 = 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;
|
|
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 != port->fifosize) ||
|
|
(((new_serial.flags ^ old_flags) & ~UPF_USR_MASK) != 0))
|
|
goto exit;
|
|
port->flags = ((port->flags & ~UPF_USR_MASK) |
|
|
(new_serial.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;
|
|
}
|
|
}
|
|
|
|
port->irq = new_serial.irq;
|
|
port->uartclk = new_serial.baud_base * 16;
|
|
port->flags = (port->flags & ~UPF_CHANGE_MASK) |
|
|
(new_serial.flags & UPF_CHANGE_MASK);
|
|
port->custom_divisor = new_serial.custom_divisor;
|
|
state->close_delay = close_delay;
|
|
state->closing_wait = closing_wait;
|
|
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:
|
|
up(&state->sem);
|
|
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;
|
|
|
|
down(&state->sem);
|
|
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);
|
|
}
|
|
up(&state->sem);
|
|
|
|
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;
|
|
|
|
down(&state->sem);
|
|
if ((!file || !tty_hung_up_p(file)) &&
|
|
!(tty->flags & (1 << TTY_IO_ERROR))) {
|
|
uart_update_mctrl(port, set, clear);
|
|
ret = 0;
|
|
}
|
|
up(&state->sem);
|
|
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());
|
|
|
|
down(&state->sem);
|
|
|
|
if (port->type != PORT_UNKNOWN)
|
|
port->ops->break_ctl(port, break_state);
|
|
|
|
up(&state->sem);
|
|
}
|
|
|
|
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 (down_interruptible(&state->sem))
|
|
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);
|
|
}
|
|
up(&state->sem);
|
|
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;
|
|
|
|
down(&state->sem);
|
|
|
|
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:
|
|
up(&state->sem);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static void uart_set_termios(struct tty_struct *tty, struct termios *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.
|
|
*/
|
|
#define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
|
|
|
|
if ((cflag ^ old_termios->c_cflag) == 0 &&
|
|
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;
|
|
|
|
DPRINTK("uart_close(%d) called\n", port->line);
|
|
|
|
down(&state->sem);
|
|
|
|
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:
|
|
up(&state->sem);
|
|
}
|
|
|
|
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;
|
|
|
|
DPRINTK("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());
|
|
DPRINTK("uart_hangup(%d)\n", state->port->line);
|
|
|
|
down(&state->sem);
|
|
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);
|
|
}
|
|
up(&state->sem);
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
mctrl = port->ops->get_mctrl(port);
|
|
spin_unlock_irq(&port->lock);
|
|
if (mctrl & TIOCM_CAR)
|
|
break;
|
|
|
|
up(&state->sem);
|
|
schedule();
|
|
down(&state->sem);
|
|
|
|
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;
|
|
|
|
down(&port_sem);
|
|
state = drv->state + line;
|
|
if (down_interruptible(&state->sem)) {
|
|
state = ERR_PTR(-ERESTARTSYS);
|
|
goto out;
|
|
}
|
|
|
|
state->count++;
|
|
if (!state->port) {
|
|
state->count--;
|
|
up(&state->sem);
|
|
state = ERR_PTR(-ENXIO);
|
|
goto out;
|
|
}
|
|
|
|
if (!state->info) {
|
|
state->info = kmalloc(sizeof(struct uart_info), GFP_KERNEL);
|
|
if (state->info) {
|
|
memset(state->info, 0, sizeof(struct uart_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 {
|
|
state->count--;
|
|
up(&state->sem);
|
|
state = ERR_PTR(-ENOMEM);
|
|
}
|
|
}
|
|
|
|
out:
|
|
up(&port_sem);
|
|
return state;
|
|
}
|
|
|
|
/*
|
|
* 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());
|
|
DPRINTK("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--;
|
|
up(&state->sem);
|
|
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);
|
|
up(&state->sem);
|
|
|
|
/*
|
|
* 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;
|
|
struct uart_port *port = state->port;
|
|
char stat_buf[32];
|
|
unsigned int status;
|
|
int ret;
|
|
|
|
if (!port)
|
|
return 0;
|
|
|
|
ret = sprintf(buf, "%d: uart:%s %s%08lX irq:%d",
|
|
port->line, uart_type(port),
|
|
port->iotype == UPIO_MEM ? "mmio:0x" : "port:",
|
|
port->iotype == UPIO_MEM ? port->mapbase :
|
|
(unsigned long) port->iobase,
|
|
port->irq);
|
|
|
|
if (port->type == PORT_UNKNOWN) {
|
|
strcat(buf, "\n");
|
|
return ret + 1;
|
|
}
|
|
|
|
if(capable(CAP_SYS_ADMIN))
|
|
{
|
|
spin_lock_irq(&port->lock);
|
|
status = port->ops->get_mctrl(port);
|
|
spin_unlock_irq(&port->lock);
|
|
|
|
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
|
|
/*
|
|
* 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 <baud><parity><bits><flow>,
|
|
* 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 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 termios termios;
|
|
int i;
|
|
|
|
/*
|
|
* Ensure that the serial console lock is initialised
|
|
* early.
|
|
*/
|
|
spin_lock_init(&port->lock);
|
|
|
|
memset(&termios, 0, sizeof(struct termios));
|
|
|
|
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;
|
|
|
|
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 (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;
|
|
|
|
down(&state->sem);
|
|
|
|
if (state->info && state->info->flags & UIF_INITIALIZED) {
|
|
struct uart_ops *ops = port->ops;
|
|
|
|
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);
|
|
|
|
up(&state->sem);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
|
|
{
|
|
struct uart_state *state = drv->state + port->line;
|
|
|
|
down(&state->sem);
|
|
|
|
uart_change_pm(state, 0);
|
|
|
|
/*
|
|
* Re-enable the console device after suspending.
|
|
*/
|
|
if (uart_console(port)) {
|
|
struct termios termios;
|
|
|
|
/*
|
|
* First try to use the console cflag setting.
|
|
*/
|
|
memset(&termios, 0, sizeof(struct termios));
|
|
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_INITIALIZED) {
|
|
struct uart_ops *ops = port->ops;
|
|
|
|
ops->set_mctrl(port, 0);
|
|
ops->startup(port);
|
|
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);
|
|
}
|
|
|
|
up(&state->sem);
|
|
|
|
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:
|
|
snprintf(address, sizeof(address),
|
|
"MMIO 0x%lx", port->mapbase);
|
|
break;
|
|
default:
|
|
strlcpy(address, "*unknown*", sizeof(address));
|
|
break;
|
|
}
|
|
|
|
printk(KERN_INFO "%s%d at %s (irq = %d) is a %s\n",
|
|
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);
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This reverses the effects of uart_configure_port, hanging up the
|
|
* port before removal.
|
|
*/
|
|
static void
|
|
uart_unconfigure_port(struct uart_driver *drv, struct uart_state *state)
|
|
{
|
|
struct uart_port *port = state->port;
|
|
struct uart_info *info = state->info;
|
|
|
|
if (info && info->tty)
|
|
tty_vhangup(info->tty);
|
|
|
|
down(&state->sem);
|
|
|
|
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);
|
|
}
|
|
|
|
up(&state->sem);
|
|
}
|
|
|
|
static 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 = kmalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
|
|
retval = -ENOMEM;
|
|
if (!drv->state)
|
|
goto out;
|
|
|
|
memset(drv->state, 0, sizeof(struct uart_state) * drv->nr);
|
|
|
|
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->devfs_name = drv->devfs_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->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
|
|
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 */
|
|
|
|
init_MUTEX(&state->sem);
|
|
}
|
|
|
|
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;
|
|
|
|
down(&port_sem);
|
|
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))
|
|
spin_lock_init(&port->lock);
|
|
|
|
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);
|
|
|
|
out:
|
|
up(&port_sem);
|
|
|
|
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;
|
|
|
|
BUG_ON(in_interrupt());
|
|
|
|
if (state->port != port)
|
|
printk(KERN_ALERT "Removing wrong port: %p != %p\n",
|
|
state->port, port);
|
|
|
|
down(&port_sem);
|
|
|
|
/*
|
|
* Remove the devices from devfs
|
|
*/
|
|
tty_unregister_device(drv->tty_driver, port->line);
|
|
|
|
uart_unconfigure_port(drv, state);
|
|
state->port = NULL;
|
|
up(&port_sem);
|
|
|
|
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:
|
|
return (port1->membase == port2->membase);
|
|
}
|
|
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");
|