patch-2.2.14 linux/drivers/net/comx-hw-mixcom.c

Next file: linux/drivers/net/comx-proto-fr.c
Previous file: linux/drivers/net/comx-hw-locomx.c
Back to the patch index
Back to the overall index

diff -u --recursive --new-file v2.2.13/linux/drivers/net/comx-hw-mixcom.c linux/drivers/net/comx-hw-mixcom.c
@@ -0,0 +1,945 @@
+/* 
+ * Hardware driver for the MixCom synchronous serial board 
+ *
+ * Author: Gergely Madarasz <gorgo@itc.hu>
+ *
+ * based on skeleton driver code and a preliminary hscx driver by 
+ * Tivadar Szemethy <tiv@itc.hu>
+ *
+ * Copyright (C) 1998-1999 ITConsult-Pro Co. <info@itc.hu>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Version 0.60 (99/06/11):
+ *		- ported to the kernel, now works as builtin code
+ *
+ * Version 0.61 (99/06/11):
+ *		- recognize the one-channel MixCOM card (id byte = 0x13)
+ *		- printk fixes
+ * 
+ * Version 0.62 (99/07/15):
+ *		- fixes according to the new hw docs 
+ *		- report line status when open
+ *
+ * Version 0.63 (99/09/21):
+ *		- line status report fixes
+ */
+
+#define VERSION "0.63"
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/netdevice.h>
+#include <linux/proc_fs.h>
+#include <asm/types.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+
+#include "comx.h"
+#include "mixcom.h"
+#include "hscx.h"
+
+MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
+MODULE_DESCRIPTION("Hardware-level driver for the serial port of the MixCom board");
+
+#define MIXCOM_DATA(d) ((struct mixcom_privdata *)(COMX_CHANNEL(d)-> \
+	HW_privdata))
+
+#define MIXCOM_BOARD_BASE(d) (d->base_addr - MIXCOM_SERIAL_OFFSET - \
+	(1 - MIXCOM_DATA(d)->channel) * MIXCOM_CHANNEL_OFFSET)
+
+#define MIXCOM_DEV_BASE(port,channel) (port + MIXCOM_SERIAL_OFFSET + \
+	(1 - channel) * MIXCOM_CHANNEL_OFFSET)
+
+/* Values used to set the IRQ line */
+static unsigned char mixcom_set_irq[]={0xFF, 0xFF, 0xFF, 0x0, 0xFF, 0x2, 0x4, 0x6, 0xFF, 0xFF, 0x8, 0xA, 0xC, 0xFF, 0xE, 0xFF};
+
+static unsigned char* hscx_versions[]={"A1", NULL, "A2", NULL, "A3", "2.1"};
+
+struct mixcom_privdata {
+	u16	clock;
+	char	channel;
+	char	txbusy;
+	struct sk_buff *sending;
+	unsigned tx_ptr;
+	struct sk_buff *recving;
+	unsigned rx_ptr;
+	unsigned char status;
+	char	card_has_status;
+};
+
+static inline void wr_hscx(struct device *dev, int reg, unsigned char val) 
+{
+	outb(val, dev->base_addr + reg);
+}
+
+static inline unsigned char rd_hscx(struct device *dev, int reg)
+{
+	return inb(dev->base_addr + reg);
+}
+
+static inline void hscx_cmd(struct device *dev, int cmd)
+{
+	unsigned long jiffs = jiffies;
+	unsigned char cec;
+	unsigned delay = 0;
+
+	while ((cec = (rd_hscx(dev, HSCX_STAR) & HSCX_CEC) != 0) && 
+	    (jiffs + HZ > jiffies)) {
+		udelay(1);
+		if (++delay > (100000 / HZ)) break;
+	}
+	if (cec) {
+		printk(KERN_WARNING "%s: CEC stuck, probably no clock!\n",dev->name);
+	} else {
+		wr_hscx(dev, HSCX_CMDR, cmd);
+	}
+}
+
+static inline void hscx_fill_fifo(struct device *dev)
+{
+	struct comx_channel *ch = dev->priv;
+	struct mixcom_privdata *hw = ch->HW_privdata;
+	register word to_send = hw->sending->len - hw->tx_ptr;
+
+
+	outsb(dev->base_addr + HSCX_FIFO,
+        	&(hw->sending->data[hw->tx_ptr]), min(to_send, 32));
+	if (to_send <= 32) {
+        	hscx_cmd(dev, HSCX_XTF | HSCX_XME);
+	        kfree_skb(hw->sending);
+        	hw->sending = NULL; 
+        	hw->tx_ptr = 0;
+        } else {
+	        hscx_cmd(dev, HSCX_XTF);
+        	hw->tx_ptr += 32;
+        }
+}
+
+static inline void hscx_empty_fifo(struct device *dev, int cnt)
+{
+	struct comx_channel *ch = dev->priv;
+	struct mixcom_privdata *hw = ch->HW_privdata;
+
+	if (hw->recving == NULL) {
+        	if (!(hw->recving = dev_alloc_skb(HSCX_MTU + 16))) {
+	                ch->stats.rx_dropped++;
+        	        hscx_cmd(dev, HSCX_RHR);
+                } else {
+	                skb_reserve(hw->recving, 16);
+        	        skb_put(hw->recving, HSCX_MTU);
+                }
+	        hw->rx_ptr = 0;
+        }
+	if (cnt > 32 || !cnt || hw->recving == NULL) {
+        	printk(KERN_ERR "hscx_empty_fifo: cnt is %d, hw->recving %p\n",
+		        cnt, (void *)hw->recving);
+	        return;
+        }
+        
+	insb(dev->base_addr + HSCX_FIFO, &(hw->recving->data[hw->rx_ptr]),cnt);
+	hw->rx_ptr += cnt;
+	hscx_cmd(dev, HSCX_RMC);
+}
+
+
+static int MIXCOM_txe(struct device *dev)
+{
+	struct comx_channel *ch = dev->priv;
+	struct mixcom_privdata *hw = ch->HW_privdata;
+
+	return !test_bit(0, &hw->txbusy);
+}
+
+static int mixcom_probe(struct device *dev)
+{
+	unsigned long flags;
+	int id, vstr, ret=0;
+
+	save_flags(flags); cli();
+
+	id=inb_p(MIXCOM_BOARD_BASE(dev) + MIXCOM_ID_OFFSET);
+
+ 	if (id != MIXCOM_ID ) {
+		ret=-ENODEV;
+		printk(KERN_WARNING "%s: no MixCOM board found at 0x%04lx\n",dev->name, dev->base_addr);
+		goto out;
+	}
+
+	vstr=inb_p(dev->base_addr + HSCX_VSTR) & 0x0f;
+	if(vstr>=sizeof(hscx_versions)/sizeof(char*) || 
+	    hscx_versions[vstr]==NULL) {
+		printk(KERN_WARNING "%s: board found but no HSCX chip detected at 0x%4lx (vstr = 0x%1x)\n",dev->name,dev->base_addr,vstr);
+		ret = -ENODEV;
+	} else {
+		printk(KERN_INFO "%s: HSCX chip version %s\n",dev->name,hscx_versions[vstr]);
+		ret = 0;
+	}
+
+out:
+
+	restore_flags(flags);
+	return ret;
+}
+
+#if 0
+static void MIXCOM_set_clock(struct device *dev)
+{
+	struct comx_channel *ch = dev->priv;
+	struct mixcom_privdata *hw = ch->HW_privdata;
+
+	if (hw->clock) {
+		;
+	} else {
+		;
+	}
+}
+#endif
+
+static void mixcom_board_on(struct device *dev)
+{
+	outb_p(MIXCOM_OFF , MIXCOM_BOARD_BASE(dev) + MIXCOM_IT_OFFSET);
+	udelay(1000);
+	outb_p(mixcom_set_irq[dev->irq] | MIXCOM_ON, 
+		MIXCOM_BOARD_BASE(dev) + MIXCOM_IT_OFFSET);
+	udelay(1000);
+}
+
+static void mixcom_board_off(struct device *dev)
+{
+	outb_p(MIXCOM_OFF , MIXCOM_BOARD_BASE(dev) + MIXCOM_IT_OFFSET);
+	udelay(1000);
+}
+
+static void mixcom_off(struct device *dev)
+{
+	wr_hscx(dev, HSCX_CCR1, 0x0);
+}
+
+static void mixcom_on(struct device *dev)
+{
+	struct comx_channel *ch = dev->priv;
+
+	wr_hscx(dev, HSCX_CCR1, HSCX_PU | HSCX_ODS | HSCX_ITF); // power up, push-pull
+	wr_hscx(dev, HSCX_CCR2, HSCX_CIE /* | HSCX_RIE */ );
+	wr_hscx(dev, HSCX_MODE, HSCX_TRANS | HSCX_ADM8 | HSCX_RAC | HSCX_RTS );
+	wr_hscx(dev, HSCX_RLCR, HSCX_RC | 47); // 1504 bytes
+	wr_hscx(dev, HSCX_MASK, HSCX_RSC | HSCX_TIN );
+	hscx_cmd(dev, HSCX_XRES | HSCX_RHR);
+
+	if (ch->HW_set_clock) ch->HW_set_clock(dev);
+
+}
+
+static int MIXCOM_send_packet(struct device *dev, struct sk_buff *skb) 
+{
+	struct comx_channel *ch = dev->priv;
+	struct mixcom_privdata *hw = ch->HW_privdata;
+	unsigned long flags;
+
+	if (ch->debug_flags & DEBUG_HW_TX) {
+		comx_debug_bytes(dev, skb->data, skb->len, "MIXCOM_send_packet");
+	}
+
+	if (!(ch->line_status & LINE_UP)) {
+		return FRAME_DROPPED;
+	}
+
+	if (skb->len > HSCX_MTU) {
+		ch->stats.tx_errors++;	
+		return FRAME_ERROR;
+	}
+
+	save_flags(flags); cli();
+
+	if (test_and_set_bit(0, &hw->txbusy)) {
+		printk(KERN_ERR "%s: transmitter called while busy... dropping frame (length %d)\n", dev->name, skb->len);
+		restore_flags(flags);
+		return FRAME_DROPPED;
+	}
+
+
+	hw->sending = skb;
+	hw->tx_ptr = 0;
+	hw->txbusy = 1;
+//	atomic_inc(&skb->users);	// save it
+	hscx_fill_fifo(dev);
+	restore_flags(flags);
+
+	ch->stats.tx_packets++;
+	ch->stats.tx_bytes += skb->len; 
+
+	if (ch->debug_flags & DEBUG_HW_TX) {
+		comx_debug(dev, "MIXCOM_send_packet was successful\n\n");
+	}
+
+	return FRAME_ACCEPTED;
+}
+
+static inline void mixcom_receive_frame(struct device *dev) 
+{
+	struct comx_channel *ch=dev->priv;
+	struct mixcom_privdata *hw=ch->HW_privdata;
+	register byte rsta;
+	register word length;
+
+	rsta = rd_hscx(dev, HSCX_RSTA) & (HSCX_VFR | HSCX_RDO | 
+		HSCX_CRC | HSCX_RAB);
+	length = ((rd_hscx(dev, HSCX_RBCH) & 0x0f) << 8) | 
+		rd_hscx(dev, HSCX_RBCL);
+
+	if ( length > hw->rx_ptr ) {
+		hscx_empty_fifo(dev, length - hw->rx_ptr);
+	}
+	
+	if (!(rsta & HSCX_VFR)) {
+		ch->stats.rx_length_errors++;
+	}
+	if (rsta & HSCX_RDO) {
+		ch->stats.rx_over_errors++;
+	}
+	if (!(rsta & HSCX_CRC)) {
+		ch->stats.rx_crc_errors++;
+	}
+	if (rsta & HSCX_RAB) {
+		ch->stats.rx_frame_errors++;
+	}
+	ch->stats.rx_packets++; 
+	ch->stats.rx_bytes += length;
+
+	if (rsta == (HSCX_VFR | HSCX_CRC) && hw->recving) {
+		skb_trim(hw->recving, hw->rx_ptr - 1);
+		if (ch->debug_flags & DEBUG_HW_RX) {
+			comx_debug_skb(dev, hw->recving,
+				"MIXCOM_interrupt receiving");
+		}
+		hw->recving->dev = dev;
+		if (ch->LINE_rx) {
+			ch->LINE_rx(dev, hw->recving);
+		}
+	}
+	else if(hw->recving) {
+		kfree_skb(hw->recving);
+	}
+	hw->recving = NULL; 
+	hw->rx_ptr = 0;
+}
+
+
+static inline void mixcom_extended_interrupt(struct device *dev) 
+{
+	struct comx_channel *ch=dev->priv;
+	struct mixcom_privdata *hw=ch->HW_privdata;
+	register byte exir;
+
+	exir = rd_hscx(dev, HSCX_EXIR) & (HSCX_XDU | HSCX_RFO | HSCX_CSC );
+
+	if (exir & HSCX_RFO) {
+		ch->stats.rx_over_errors++;
+		if (hw->rx_ptr) {
+			kfree_skb(hw->recving);
+			hw->recving = NULL; hw->rx_ptr = 0;
+		}
+		printk(KERN_ERR "MIXCOM: rx overrun\n");
+		hscx_cmd(dev, HSCX_RHR);
+	}
+
+	if (exir & HSCX_XDU) { // xmit underrun
+		ch->stats.tx_errors++;
+		ch->stats.tx_aborted_errors++;
+		if (hw->tx_ptr) {
+			kfree_skb(hw->sending);
+			hw->sending = NULL; 
+			hw->tx_ptr = 0;
+		}
+		hscx_cmd(dev, HSCX_XRES);
+		clear_bit(0, &hw->txbusy);
+		if (ch->LINE_tx) {
+			ch->LINE_tx(dev);
+		}
+		printk(KERN_ERR "MIXCOM: tx underrun\n");
+	}
+
+	if (exir & HSCX_CSC) {        
+		ch->stats.tx_carrier_errors++;
+		if ((rd_hscx(dev, HSCX_STAR) & HSCX_CTS) == 0) { // Vonal le
+			if (test_and_clear_bit(0, &ch->lineup_pending)) {
+               			del_timer(&ch->lineup_timer);
+			} else if (ch->line_status & LINE_UP) {
+        		       	ch->line_status &= ~LINE_UP;
+                		if (ch->LINE_status) {
+                      			ch->LINE_status(dev,ch->line_status);
+                      		}
+		      	}
+		}
+		if (!(ch->line_status & LINE_UP) && (rd_hscx(dev, HSCX_STAR) & 
+		    HSCX_CTS)) { // Vonal fol
+			if (!test_and_set_bit(0,&ch->lineup_pending)) {
+				ch->lineup_timer.function = comx_lineup_func;
+	        	        ch->lineup_timer.data = (unsigned long)dev;
+        	        	ch->lineup_timer.expires = jiffies + HZ * 
+        	        		ch->lineup_delay;
+	                	add_timer(&ch->lineup_timer);
+		                hscx_cmd(dev, HSCX_XRES);
+        		        clear_bit(0, &hw->txbusy);
+                		if (hw->sending) {
+					kfree_skb(hw->sending);
+				}
+				hw->sending=NULL;
+				hw->tx_ptr = 0;
+			}
+		}
+	}
+}
+
+
+static void MIXCOM_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	unsigned long flags;
+	struct device *dev = (struct device *)dev_id;
+	struct comx_channel *ch, *twin_ch;
+	struct mixcom_privdata *hw, *twin_hw;
+	register unsigned char ista;
+
+	if (dev==NULL) {
+		printk(KERN_ERR "comx_interrupt: irq %d for unknown device\n",irq);
+		return;
+	}
+
+	ch = dev->priv; 
+	hw = ch->HW_privdata;
+
+	save_flags(flags); cli(); 
+
+	while((ista = (rd_hscx(dev, HSCX_ISTA) & (HSCX_RME | HSCX_RPF | 
+	    HSCX_XPR | HSCX_EXB | HSCX_EXA | HSCX_ICA)))) {
+		register byte ista2 = 0;
+
+		if (ista & HSCX_RME) {
+			mixcom_receive_frame(dev);
+		}
+		if (ista & HSCX_RPF) {
+			hscx_empty_fifo(dev, 32);
+		}
+		if (ista & HSCX_XPR) {
+			if (hw->tx_ptr) {
+				hscx_fill_fifo(dev);
+			} else {
+				clear_bit(0, &hw->txbusy);
+               			ch->LINE_tx(dev);
+			}
+		}
+		
+		if (ista & HSCX_EXB) {
+			mixcom_extended_interrupt(dev);
+		}
+		
+		if ((ista & HSCX_EXA) && ch->twin)  {
+			mixcom_extended_interrupt(ch->twin);
+		}
+	
+		if ((ista & HSCX_ICA) && ch->twin &&
+		    (ista2 = rd_hscx(ch->twin, HSCX_ISTA) &
+		    (HSCX_RME | HSCX_RPF | HSCX_XPR ))) {
+			if (ista2 & HSCX_RME) {
+				mixcom_receive_frame(ch->twin);
+			}
+			if (ista2 & HSCX_RPF) {
+				hscx_empty_fifo(ch->twin, 32);
+			}
+			if (ista2 & HSCX_XPR) {
+				twin_ch=ch->twin->priv;
+				twin_hw=twin_ch->HW_privdata;
+				if (twin_hw->tx_ptr) {
+					hscx_fill_fifo(ch->twin);
+				} else {
+					clear_bit(0, &twin_hw->txbusy);
+					ch->LINE_tx(ch->twin);
+				}
+			}
+		}
+	}
+
+	restore_flags(flags);
+	return;
+}
+
+static int MIXCOM_open(struct device *dev)
+{
+	struct comx_channel *ch = dev->priv;
+	struct mixcom_privdata *hw = ch->HW_privdata;
+	struct proc_dir_entry *procfile = ch->procdir->subdir;
+	unsigned long flags; 
+
+	if (!dev->base_addr || !dev->irq) return -ENODEV;
+
+
+	if(hw->channel==1) {
+		if(!TWIN(dev) || !(COMX_CHANNEL(TWIN(dev))->init_status & 
+		    IRQ_ALLOCATED)) {
+			printk(KERN_ERR "%s: channel 0 not yet initialized\n",dev->name);
+			return -EAGAIN;
+		}
+	}
+
+
+	/* Is our hw present at all ? Not checking for channel 0 if it is already 
+	   open */
+	if(hw->channel!=0 || !(ch->init_status & IRQ_ALLOCATED)) {
+		if (check_region(dev->base_addr, MIXCOM_IO_EXTENT)) {
+			return -EAGAIN;
+		}
+		if (mixcom_probe(dev)) {
+			return -ENODEV;
+		}
+	}
+
+	save_flags(flags); cli();
+
+	if(hw->channel==1) {
+		request_region(dev->base_addr, MIXCOM_IO_EXTENT, dev->name);
+	} 
+
+	if(hw->channel==0 && !(ch->init_status & IRQ_ALLOCATED)) {
+		if (request_irq(dev->irq, MIXCOM_interrupt, 0, 
+		    dev->name, (void *)dev)) {
+			printk(KERN_ERR "MIXCOM: unable to obtain irq %d\n", dev->irq);
+			return -EAGAIN;
+		}
+		ch->init_status|=IRQ_ALLOCATED;
+		request_region(dev->base_addr, MIXCOM_IO_EXTENT, dev->name);
+		mixcom_board_on(dev);
+	}
+
+	mixcom_on(dev);
+
+	restore_flags(flags);
+
+	hw->status=inb(MIXCOM_BOARD_BASE(dev) + MIXCOM_STATUS_OFFSET);
+	if(hw->status != 0xff) {
+		printk(KERN_DEBUG "%s: board has status register, good\n", dev->name);
+		hw->card_has_status=1;
+	}
+
+	hw->txbusy = 0;
+	ch->init_status |= HW_OPEN;
+	
+	if (rd_hscx(dev, HSCX_STAR) & HSCX_CTS) {
+		ch->line_status |= LINE_UP;
+	} else {
+		ch->line_status &= ~LINE_UP;
+	}
+
+	ch->LINE_status(dev, ch->line_status);
+
+	for (; procfile ; procfile = procfile->next) {
+		if (strcmp(procfile->name, FILENAME_IO) == 0 ||
+		    strcmp(procfile->name, FILENAME_CHANNEL) == 0 ||
+		    strcmp(procfile->name, FILENAME_CLOCK) == 0 ||
+		    strcmp(procfile->name, FILENAME_IRQ) == 0) {
+			procfile->mode = S_IFREG |  0444;
+		}
+	}
+
+	return 0;
+}
+
+static int MIXCOM_close(struct device *dev)
+{
+	struct comx_channel *ch = dev->priv;
+	struct mixcom_privdata *hw = ch->HW_privdata;
+	struct proc_dir_entry *procfile = ch->procdir->subdir;
+	unsigned long flags;
+
+
+	save_flags(flags); cli();
+
+	mixcom_off(dev);
+
+	/* This is channel 0, twin is not open, we can safely turn off everything */
+	if(hw->channel==0 && (!(TWIN(dev)) || 
+	    !(COMX_CHANNEL(TWIN(dev))->init_status & HW_OPEN))) {
+		mixcom_board_off(dev);
+		free_irq(dev->irq, dev);
+		release_region(dev->base_addr, MIXCOM_IO_EXTENT);
+		ch->init_status &= ~IRQ_ALLOCATED;
+	}
+
+	/* This is channel 1, channel 0 has already been shutdown, we can release
+	   this one too */
+	if(hw->channel==1 && !(COMX_CHANNEL(TWIN(dev))->init_status & HW_OPEN)) {
+		if(COMX_CHANNEL(TWIN(dev))->init_status & IRQ_ALLOCATED) {
+			mixcom_board_off(TWIN(dev));
+			free_irq(TWIN(dev)->irq, TWIN(dev));
+			release_region(TWIN(dev)->base_addr, MIXCOM_IO_EXTENT);
+			COMX_CHANNEL(TWIN(dev))->init_status &= ~IRQ_ALLOCATED;
+		}
+	}
+
+	/* the ioports for channel 1 can be safely released */
+	if(hw->channel==1) {
+		release_region(dev->base_addr, MIXCOM_IO_EXTENT);
+	}
+
+	restore_flags(flags);
+
+	/* If we don't hold any hardware open */
+	if(!(ch->init_status & IRQ_ALLOCATED)) {
+		for (; procfile ; procfile = procfile->next) {
+			if (strcmp(procfile->name, FILENAME_IO) == 0 ||
+			    strcmp(procfile->name, FILENAME_CHANNEL) == 0 ||
+			    strcmp(procfile->name, FILENAME_CLOCK) == 0 ||
+			    strcmp(procfile->name, FILENAME_IRQ) == 0) {
+				procfile->mode = S_IFREG |  0644;
+			}
+		}
+	}
+
+	/* channel 0 was only waiting for us to close channel 1 
+	   close it completely */
+   
+	if(hw->channel==1 && !(COMX_CHANNEL(TWIN(dev))->init_status & HW_OPEN)) {
+		for (procfile=COMX_CHANNEL(TWIN(dev))->procdir->subdir; 
+		    procfile ; procfile = procfile->next) {
+			if (strcmp(procfile->name, FILENAME_IO) == 0 ||
+			    strcmp(procfile->name, FILENAME_CHANNEL) == 0 ||
+			    strcmp(procfile->name, FILENAME_CLOCK) == 0 ||
+			    strcmp(procfile->name, FILENAME_IRQ) == 0) {
+				procfile->mode = S_IFREG |  0644;
+			}
+		}
+	}
+	
+	ch->init_status &= ~HW_OPEN;
+	return 0;
+}
+
+static int MIXCOM_statistics(struct device *dev,char *page)
+{
+	struct comx_channel *ch = dev->priv;
+	// struct mixcom_privdata *hw = ch->HW_privdata;
+	int len = 0;
+
+	if(ch->init_status && IRQ_ALLOCATED) {
+		len += sprintf(page + len, "Mixcom board: hardware open\n");
+	}
+
+	return len;
+}
+
+static int MIXCOM_dump(struct device *dev) {
+	return 0;
+}
+
+static int mixcom_read_proc(char *page, char **start, off_t off, int count,
+	int *eof, void *data)
+{
+	struct proc_dir_entry *file = (struct proc_dir_entry *)data;
+	struct device *dev = file->parent->data;
+	struct comx_channel *ch = dev->priv;
+	struct mixcom_privdata *hw = ch->HW_privdata;
+	int len = 0;
+
+	if (strcmp(file->name, FILENAME_IO) == 0) {
+		len = sprintf(page, "0x%x\n", 
+			(unsigned int)MIXCOM_BOARD_BASE(dev));
+	} else if (strcmp(file->name, FILENAME_IRQ) == 0) {
+		len = sprintf(page, "%d\n", (unsigned int)dev->irq);
+	} else if (strcmp(file->name, FILENAME_CLOCK) == 0) {
+		if (hw->clock) len = sprintf(page, "%d\n", hw->clock);
+			else len = sprintf(page, "external\n");
+	} else if (strcmp(file->name, FILENAME_CHANNEL) == 0) {
+		len = sprintf(page, "%01d\n", hw->channel);
+	} else if (strcmp(file->name, FILENAME_TWIN) == 0) {
+		if (ch->twin) {
+			len = sprintf(page, "%s\n",ch->twin->name);
+		} else {
+			len = sprintf(page, "none\n");
+		}
+	} else {
+		printk(KERN_ERR "mixcom_read_proc: internal error, filename %s\n", file->name);
+		return -EBADF;
+	}
+
+	if (off >= len) {
+		*eof = 1;
+		return 0;
+	}
+	*start = page + off;
+	if (count >= len - off) *eof = 1;
+	return ( min(count, len - off) );
+}
+
+
+static struct device *mixcom_twin_check(struct device *dev)
+{
+	struct comx_channel *ch = dev->priv;
+	struct proc_dir_entry *procfile = ch->procdir->parent->subdir;
+	struct mixcom_privdata *hw = ch->HW_privdata;
+
+	struct device *twin;
+	struct comx_channel *ch_twin;
+	struct mixcom_privdata *hw_twin;
+
+
+	for ( ; procfile ; procfile = procfile->next) {
+		if(!S_ISDIR(procfile->mode)) continue;
+                
+        	twin = procfile->data;
+	        ch_twin = twin->priv;
+        	hw_twin = ch_twin->HW_privdata;
+
+
+	        if (twin != dev && dev->irq && dev->base_addr && 
+        	    dev->irq == twin->irq && 
+        	    ch->hardware == ch_twin->hardware &&
+		    dev->base_addr == twin->base_addr + 
+		    (1-2*hw->channel)*MIXCOM_CHANNEL_OFFSET &&
+		    hw->channel == (1 - hw_twin->channel)) {
+	        	if  (!TWIN(twin) || TWIN(twin)==dev) {
+	        		return twin;
+	        	}
+		}
+        }
+	return NULL;
+}
+
+
+static void setup_twin(struct device* dev) 
+{
+
+	if(TWIN(dev) && TWIN(TWIN(dev))) {
+		TWIN(TWIN(dev))=NULL;
+	}
+	if ((TWIN(dev) = mixcom_twin_check(dev)) != NULL) {
+		if (TWIN(TWIN(dev)) && TWIN(TWIN(dev)) != dev) {
+			TWIN(dev)=NULL;
+		} else {
+			TWIN(TWIN(dev))=dev;
+		}
+	}	
+}
+
+static int mixcom_write_proc(struct file *file, const char *buffer,
+	u_long count, void *data)
+{
+	struct proc_dir_entry *entry = (struct proc_dir_entry *)data;
+	struct device *dev = (struct device *)entry->parent->data;
+	struct comx_channel *ch = dev->priv;
+	struct mixcom_privdata *hw = ch->HW_privdata;
+	char *page;
+	int value;
+
+	if (file->f_dentry->d_inode->i_ino != entry->low_ino) {
+		printk(KERN_ERR "mixcom_write_proc: file <-> data internal error\n");
+		return -EIO;
+	}
+
+	if (!(page = (char *)__get_free_page(GFP_KERNEL))) {
+		return -ENOMEM;
+	}
+
+	copy_from_user(page, buffer, count = min(count, PAGE_SIZE));
+	if (*(page + count - 1) == '\n') {
+		*(page + count - 1) = 0;
+	}
+
+	if (strcmp(entry->name, FILENAME_IO) == 0) {
+		value = simple_strtoul(page, NULL, 0);
+		if (value != 0x180 && value != 0x280 && value != 0x380) {
+			printk(KERN_ERR "MIXCOM: incorrect io address!\n");
+		} else {
+			dev->base_addr = MIXCOM_DEV_BASE(value,hw->channel);
+		}
+	} else if (strcmp(entry->name, FILENAME_IRQ) == 0) {
+		value = simple_strtoul(page, NULL, 0); 
+		if (value < 0 || value > 15 || mixcom_set_irq[value]==0xFF) {
+			printk(KERN_ERR "MIXCOM: incorrect irq value!\n");
+		} else {
+			dev->irq = value;	
+		}
+	} else if (strcmp(entry->name, FILENAME_CLOCK) == 0) {
+		if (strncmp("ext", page, 3) == 0) {
+			hw->clock = 0;
+		} else {
+			int kbps;
+
+			kbps = simple_strtoul(page, NULL, 0);
+			if (!kbps) {
+				hw->clock = 0;
+			} else {
+				hw->clock = kbps;
+			}
+			if (hw->clock < 32 || hw->clock > 2000) {
+				hw->clock = 0;
+				printk(KERN_ERR "MIXCOM: invalid clock rate!\n");
+			}
+		}
+		if (ch->init_status & HW_OPEN && ch->HW_set_clock) {
+			ch->HW_set_clock(dev);
+		}
+	} else if (strcmp(entry->name, FILENAME_CHANNEL) == 0) {
+		value = simple_strtoul(page, NULL, 0);
+        	if (value > 2) {
+                	printk(KERN_ERR "Invalid channel number\n");
+	        } else {
+        		dev->base_addr+=(hw->channel - value) * MIXCOM_CHANNEL_OFFSET;
+	        	hw->channel = value;
+		}	        
+	} else {
+		printk(KERN_ERR "hw_read_proc: internal error, filename %s\n", 
+			entry->name);
+		return -EBADF;
+	}
+
+	setup_twin(dev);
+
+	free_page((unsigned long)page);
+	return count;
+}
+
+static int MIXCOM_init(struct device *dev) {
+	struct comx_channel *ch = dev->priv;
+	struct mixcom_privdata *hw;
+	struct proc_dir_entry *new_file;
+
+	if ((ch->HW_privdata = kmalloc(sizeof(struct mixcom_privdata), 
+	    GFP_KERNEL)) == NULL) {
+	    	return -ENOMEM;
+	}
+
+	memset(hw = ch->HW_privdata, 0, sizeof(struct mixcom_privdata));
+
+	if ((new_file = create_proc_entry(FILENAME_IO, S_IFREG | 0644, 
+	    ch->procdir)) == NULL) {
+		return -EIO;
+	}
+	new_file->data = (void *)new_file;
+	new_file->read_proc = &mixcom_read_proc;
+	new_file->write_proc = &mixcom_write_proc;
+	new_file->ops = &comx_normal_inode_ops;
+	new_file->nlink = 1;
+
+	if ((new_file = create_proc_entry(FILENAME_IRQ, S_IFREG | 0644, 
+	    ch->procdir)) == NULL) {
+	    	return -EIO;
+	}
+	new_file->data = (void *)new_file;
+	new_file->read_proc = &mixcom_read_proc;
+	new_file->write_proc = &mixcom_write_proc;
+	new_file->ops = &comx_normal_inode_ops;
+	new_file->nlink = 1;
+
+#if 0
+	if ((new_file = create_proc_entry(FILENAME_CLOCK, S_IFREG | 0644, 
+	    ch->procdir)) == NULL) {
+	    	return -EIO;
+	}
+	new_file->data = (void *)new_file;
+	new_file->read_proc = &mixcom_read_proc;
+	new_file->write_proc = &mixcom_write_proc;
+	new_file->ops = &comx_normal_inode_ops;
+	new_file->nlink = 1;
+#endif
+
+	if ((new_file = create_proc_entry(FILENAME_CHANNEL, S_IFREG | 0644, 
+	    ch->procdir)) == NULL) {
+	    	return -EIO;
+	}
+	new_file->data = (void *)new_file;
+	new_file->read_proc = &mixcom_read_proc;
+	new_file->write_proc = &mixcom_write_proc;
+	new_file->ops = &comx_normal_inode_ops;
+	new_file->nlink = 1;
+
+	if ((new_file = create_proc_entry(FILENAME_TWIN, S_IFREG | 0444, 
+	    ch->procdir)) == NULL) {
+	    	return -EIO;
+	}
+	new_file->data = (void *)new_file;
+	new_file->read_proc = &mixcom_read_proc;
+	new_file->write_proc = &mixcom_write_proc;
+	new_file->ops = &comx_normal_inode_ops;
+	new_file->nlink = 1;
+
+	setup_twin(dev);
+
+	/* Fill in ch_struct hw specific pointers */
+	ch->HW_access_board = NULL;
+	ch->HW_release_board = NULL;
+	ch->HW_txe = MIXCOM_txe;
+	ch->HW_open = MIXCOM_open;
+	ch->HW_close = MIXCOM_close;
+	ch->HW_send_packet = MIXCOM_send_packet;
+	ch->HW_statistics = MIXCOM_statistics;
+	ch->HW_set_clock = NULL;
+
+	dev->base_addr = MIXCOM_DEV_BASE(MIXCOM_DEFAULT_IO,0);
+	dev->irq = MIXCOM_DEFAULT_IRQ;
+
+	MOD_INC_USE_COUNT;
+	return 0;
+}
+
+static int MIXCOM_exit(struct device *dev)
+{
+	struct comx_channel *ch = dev->priv;
+	struct mixcom_privdata *hw = ch->HW_privdata;
+
+	if(hw->channel==0 && TWIN(dev)) {
+		return -EBUSY;
+	}
+
+	if(hw->channel==1 && TWIN(dev)) {
+		TWIN(TWIN(dev))=NULL;
+	}
+
+	kfree(ch->HW_privdata);
+	remove_proc_entry(FILENAME_IO, ch->procdir);
+	remove_proc_entry(FILENAME_IRQ, ch->procdir);
+#if 0
+	remove_proc_entry(FILENAME_CLOCK, ch->procdir);
+#endif
+	remove_proc_entry(FILENAME_CHANNEL, ch->procdir);
+	remove_proc_entry(FILENAME_TWIN, ch->procdir);
+
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
+
+static struct comx_hardware mixcomhw = {
+	"mixcom",
+	VERSION,
+	MIXCOM_init, 
+	MIXCOM_exit,
+	MIXCOM_dump,
+	NULL
+};
+	
+/* Module management */
+
+#ifdef MODULE
+#define comx_hw_mixcom_init init_module
+#endif
+
+__initfunc(int comx_hw_mixcom_init(void))
+{
+	return(comx_register_hardware(&mixcomhw));
+}
+
+#ifdef MODULE
+void
+cleanup_module(void)
+{
+	comx_unregister_hardware("mixcom");
+}
+#endif
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)