synclink.c

powerpc内核mpc8241linux系统下char驱动程序

	
	/* perform existance check and diagnostics */
	if ( !retval )
		retval = mgsl_adapter_test(info);
		
	if ( retval ) {
#if LINUX_VERSION_CODE >= VERSION(2,1,0)
  		if (capable(CAP_SYS_ADMIN) && info->tty)
#else
  		if (suser() && info->tty)
#endif		
			set_bit(TTY_IO_ERROR, &info->tty->flags);
		mgsl_release_resources(info);
  		return retval;
  	}

	/* program hardware for current parameters */
	mgsl_change_params(info);
	
	if (info->tty)
		clear_bit(TTY_IO_ERROR, &info->tty->flags);

	info->flags |= ASYNC_INITIALIZED;
	
	return 0;
	
}	/* end of startup() */

/* shutdown()
 *
 * Called by mgsl_close() and mgsl_hangup() to shutdown hardware
 *
 * Arguments:		info	pointer to device instance data
 * Return Value:	None
 */
static void shutdown(struct mgsl_struct * info)
{
	unsigned long flags;
	
	if (!(info->flags & ASYNC_INITIALIZED))
		return;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgsl_shutdown(%s)\n",
			 __FILE__,__LINE__, info->device_name );

	/* clear status wait queue because status changes */
	/* can't happen after shutting down the hardware */
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);

	if (info->xmit_buf) {
		free_page((unsigned long) info->xmit_buf);
		info->xmit_buf = 0;
	}

	spin_lock_irqsave(&info->irq_spinlock,flags);
	usc_DisableMasterIrqBit(info);
	usc_stop_receiver(info);
	usc_stop_transmitter(info);
	usc_DisableInterrupts(info,RECEIVE_DATA + RECEIVE_STATUS +
		TRANSMIT_DATA + TRANSMIT_STATUS + IO_PIN + MISC );
	usc_DisableDmaInterrupts(info,DICR_MASTER + DICR_TRANSMIT + DICR_RECEIVE);
	
	/* Disable DMAEN (Port 7, Bit 14) */
	/* This disconnects the DMA request signal from the ISA bus */
	/* on the ISA adapter. This has no effect for the PCI adapter */
	usc_OutReg(info, PCR, (u16)((usc_InReg(info, PCR) | BIT15) | BIT14));
	
	/* Disable INTEN (Port 6, Bit12) */
	/* This disconnects the IRQ request signal to the ISA bus */
	/* on the ISA adapter. This has no effect for the PCI adapter */
	usc_OutReg(info, PCR, (u16)((usc_InReg(info, PCR) | BIT13) | BIT12));
	
 	if (!info->tty || info->tty->termios->c_cflag & HUPCL) {
 		info->serial_signals &= ~(SerialSignal_DTR + SerialSignal_RTS);
		usc_set_serial_signals(info);
	}
	
	spin_unlock_irqrestore(&info->irq_spinlock,flags);

	mgsl_release_resources(info);	
	
	if (info->tty)
		set_bit(TTY_IO_ERROR, &info->tty->flags);

	info->flags &= ~ASYNC_INITIALIZED;
	
}	/* end of shutdown() */

/* mgsl_change_params()
 *
 *	Reconfigure adapter based on new parameters
 *
 * Arguments:		info	pointer to device instance data
 * Return Value:	None
 */
static void mgsl_change_params(struct mgsl_struct *info)
{
	unsigned cflag;
	unsigned long flags;
	int bits_per_char;

	if (!info->tty || !info->tty->termios)
		return;
		
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgsl_change_params(%s)\n",
			 __FILE__,__LINE__, info->device_name );
			 
	cflag = info->tty->termios->c_cflag;

	/* if B0 rate (hangup) specified then negate DTR and RTS */
	/* otherwise assert DTR and RTS */
 	if (cflag & CBAUD)
		info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
	else
		info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
	
	/* byte size and parity */
	
	switch (cflag & CSIZE) {
	      case CS5: info->params.data_bits = 5; break;
	      case CS6: info->params.data_bits = 6; break;
	      case CS7: info->params.data_bits = 7; break;
	      case CS8: info->params.data_bits = 8; break;
	      /* Never happens, but GCC is too dumb to figure it out */
	      default:  info->params.data_bits = 7; break;
	      }
	      
	if (cflag & CSTOPB)
		info->params.stop_bits = 2;
	else
		info->params.stop_bits = 1;

	info->params.parity = ASYNC_PARITY_NONE;
	if (cflag & PARENB) {
		if (cflag & PARODD)
			info->params.parity = ASYNC_PARITY_ODD;
		else
			info->params.parity = ASYNC_PARITY_EVEN;
#ifdef CMSPAR
		if (cflag & CMSPAR)
			info->params.parity = ASYNC_PARITY_SPACE;
#endif
	}

	/* calculate number of jiffies to transmit a full
	 * FIFO (32 bytes) at specified data rate
	 */
	bits_per_char = info->params.data_bits + 
			info->params.stop_bits + 1;

	/* if port data rate is set to 460800 or less then
	 * allow tty settings to override, otherwise keep the
	 * current data rate.
	 */
	if (info->params.data_rate <= 460800) {
#if LINUX_VERSION_CODE >= VERSION(2,1,0)
		info->params.data_rate = tty_get_baud_rate(info->tty);
#else
		int i = cflag & CBAUD;
		if (i & CBAUDEX) {
			i &= ~CBAUDEX;
			if (i < 1 || i > 4) 
				info->tty->termios->c_cflag &= ~CBAUDEX;
			else
				i += 15;
		}
		info->params.data_rate = baud_table[i];
#endif	
	}
	
	if ( info->params.data_rate ) {
		info->timeout = (32*HZ*bits_per_char) / 
				info->params.data_rate;
	}
	info->timeout += HZ/50;		/* Add .02 seconds of slop */

	if (cflag & CRTSCTS)
		info->flags |= ASYNC_CTS_FLOW;
	else
		info->flags &= ~ASYNC_CTS_FLOW;
		
	if (cflag & CLOCAL)
		info->flags &= ~ASYNC_CHECK_CD;
	else
		info->flags |= ASYNC_CHECK_CD;

	/* process tty input control flags */
	
	info->read_status_mask = RXSTATUS_OVERRUN;
	if (I_INPCK(info->tty))
		info->read_status_mask |= RXSTATUS_PARITY_ERROR | RXSTATUS_FRAMING_ERROR;
 	if (I_BRKINT(info->tty) || I_PARMRK(info->tty))
 		info->read_status_mask |= RXSTATUS_BREAK_RECEIVED;
	
	if (I_IGNPAR(info->tty))
		info->ignore_status_mask |= RXSTATUS_PARITY_ERROR | RXSTATUS_FRAMING_ERROR;
	if (I_IGNBRK(info->tty)) {
		info->ignore_status_mask |= RXSTATUS_BREAK_RECEIVED;
		/* If ignoring parity and break indicators, ignore 
		 * overruns too.  (For real raw support).
		 */
		if (I_IGNPAR(info->tty))
			info->ignore_status_mask |= RXSTATUS_OVERRUN;
	}

	/* reprogram the hardware */
	
	spin_lock_irqsave(&info->irq_spinlock,flags);
	
	usc_stop_receiver(info);
	usc_stop_transmitter(info);
	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
	
	if ( info->params.mode == MGSL_MODE_HDLC )
		usc_set_sync_mode(info);
	else
		usc_set_async_mode(info);
		
	usc_set_serial_signals(info);

	/* enable modem signal IRQs and read initial signal states */
	usc_EnableStatusIrqs(info,SICR_CTS+SICR_DSR+SICR_DCD+SICR_RI);		
	usc_EnableInterrupts(info, IO_PIN);
	usc_get_serial_signals(info);
		
	if ( cflag & CREAD )
		usc_start_receiver(info);
		
	spin_unlock_irqrestore(&info->irq_spinlock,flags);

}	/* end of mgsl_change_params() */

/* mgsl_put_char()
 * 
 * 	Add a character to the transmit buffer.
 * 	
 * Arguments:		tty	pointer to tty information structure
 * 			ch	character to add to transmit buffer
 * 		
 * Return Value:	None
 */
static void mgsl_put_char(struct tty_struct *tty, unsigned char ch)
{
	struct mgsl_struct *info = (struct mgsl_struct *)tty->driver_data;
	unsigned long flags;

	if ( debug_level >= DEBUG_LEVEL_INFO ) {
		printk( "%s(%d):mgsl_put_char(%d) on %s\n",
			__FILE__,__LINE__,ch,info->device_name);
	}		
	
	if (mgsl_paranoia_check(info, tty->device, "mgsl_put_char"))
		return;

	if (!tty || !info->xmit_buf)
		return;

	spin_lock_irqsave(&info->irq_spinlock,flags);
	
	if ( (info->params.mode != MGSL_MODE_HDLC) || 
	     !info->tx_active ) {
	
		if (info->xmit_cnt < SERIAL_XMIT_SIZE - 1) {
			info->xmit_buf[info->xmit_head++] = ch;
			info->xmit_head &= SERIAL_XMIT_SIZE-1;
			info->xmit_cnt++;
		}
	}
	
	spin_unlock_irqrestore(&info->irq_spinlock,flags);
	
}	/* end of mgsl_put_char() */

/* mgsl_flush_chars()
 * 
 * 	Enable transmitter so remaining characters in the
 * 	transmit buffer are sent.
 * 	
 * Arguments:		tty	pointer to tty information structure
 * Return Value:	None
 */
static void mgsl_flush_chars(struct tty_struct *tty)
{
	struct mgsl_struct *info = (struct mgsl_struct *)tty->driver_data;
	unsigned long flags;
				
	if ( debug_level >= DEBUG_LEVEL_INFO )
		printk( "%s(%d):mgsl_flush_chars() entry on %s xmit_cnt=%d\n",
			__FILE__,__LINE__,info->device_name,info->xmit_cnt);
	
	if (mgsl_paranoia_check(info, tty->device, "mgsl_flush_chars"))
		return;

	if (info->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
	    !info->xmit_buf)
		return;

	if ( debug_level >= DEBUG_LEVEL_INFO )
		printk( "%s(%d):mgsl_flush_chars() entry on %s starting transmitter\n",
			__FILE__,__LINE__,info->device_name );

	spin_lock_irqsave(&info->irq_spinlock,flags);
	
	if (!info->tx_active) {
		if ( (info->params.mode == MGSL_MODE_HDLC) &&
			info->xmit_cnt ) {
			/* operating in synchronous (frame oriented) mode */
			/* copy data from circular xmit_buf to */
			/* transmit DMA buffer. */
			mgsl_load_tx_dma_buffer(info,
				 info->xmit_buf,info->xmit_cnt);
		}
	 	usc_start_transmitter(info);
	}
	
	spin_unlock_irqrestore(&info->irq_spinlock,flags);
	
}	/* end of mgsl_flush_chars() */

/* mgsl_write()
 * 
 * 	Send a block of data
 * 	
 * Arguments:
 * 
 * 	tty		pointer to tty information structure
 * 	from_user	flag: 1 = from user process
 * 	buf		pointer to buffer containing send data
 * 	count		size of send data in bytes
 * 	
 * Return Value:	number of characters written
 */
static int mgsl_write(struct tty_struct * tty, int from_user,
		    const unsigned char *buf, int count)
{
	int	c, ret = 0, err;
	struct mgsl_struct *info = (struct mgsl_struct *)tty->driver_data;
	unsigned long flags;
	
	if ( debug_level >= DEBUG_LEVEL_INFO )
		printk( "%s(%d):mgsl_write(%s) count=%d\n",
			__FILE__,__LINE__,info->device_name,count);
	
	if (mgsl_paranoia_check(info, tty->device, "mgsl_write"))
		goto cleanup;

	if (!tty || !info->xmit_buf || !tmp_buf)
		goto cleanup;

	if ( info->params.mode == MGSL_MODE_HDLC ) {
		/* operating in synchronous (frame oriented) mode */
	
		if (info->tx_active) {
			ret = 0; goto cleanup; 
		}
		
		if ( info->xmit_cnt ) {
			/* Send accumulated from send_char() calls */
			/* as frame and wait before accepting more data. */
			ret = 0;
				
			/* copy data from circular xmit_buf to */
			/* transmit DMA buffer. */
			mgsl_load_tx_dma_buffer(info,
				info->xmit_buf,info->xmit_cnt);
			if ( debug_level >= DEBUG_LEVEL_INFO )
				printk( "%s(%d):mgsl_write(%s) sync xmit_cnt flushing\n",
					__FILE__,__LINE__,info->device_name);
		} else {
			if ( debug_level >= DEBUG_LEVEL_INFO )
				printk( "%s(%d):mgsl_write(%s) sync transmit accepted\n",
					__FILE__,__LINE__,info->device_name);
			ret = count;
			info->xmit_cnt = count;
			if (from_user) {
				down(&tmp_buf_sem);
				COPY_FROM_USER(err,tmp_buf, buf, count);
				if (err) {
					if ( debug_level >= DEBUG_LEVEL_INFO )
						printk( "%s(%d):mgsl_write(%s) sync user buf copy failed\n",
							__FILE__,__LINE__,info->device_name);
					ret = -EFAULT;
				} else
					mgsl_load_tx_dma_buffer(info,tmp_buf,count);
				up(&tmp_buf_sem);
			}
			else
				mgsl_load_tx_dma_buffer(info,buf,count);
		}
	} else {
		if (from_user) {
			down(&tmp_buf_sem);
			while (1) {
				c = MIN(count,
					MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
					    SERIAL_XMIT_SIZE - info->xmit_head));
				if (c <= 0)
					break;

				COPY_FROM_USER(err,tmp_buf, buf, c);
				c -= err;
				if (!c) {
					if (!ret)
						ret = -EFAULT;
					break;
				}
				spin_lock_irqsave(&info->irq_spinlock,flags);
				c = MIN(c, MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
					       SERIAL_XMIT_SIZE - info->xmit_head));
				memcpy(info->xmit_buf + info->xmit_head, tmp_buf, c);
				info->xmit_head = ((info->xmit_head + c) &
						   (SERIAL_XMIT_SIZE-1));
				info->xmit_cnt += c;
				spin_unlock_irqrestore(&info->irq_spinlock,flags);
				buf += c;
				count -= c;
				ret += c;
			}
			up(&tmp_buf_sem);
		} else {
			while (1) {
				spin_lock_irqsave(&info->irq_spinlock,flags);
				c = MIN(count,
					MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
					    SERIAL_XMIT_SIZE - info->xmit_head));
				if (c <= 0) {
					spin_unlock_irqrestore(&info->irq_spinlock,flags);
					break;
				}
				memcpy(info->xmit_buf + info->xmit_head, buf, c);
				info->xmit_head = ((info->xmit_head + c) &
						   (SERIAL_XMIT_SIZE-1));
				info->xmit_cnt += c;
				spin_unlock_irqrestore(&info->irq_spinlock,flags);
				buf += c;
				count -= c;