patch-2.1.121 linux/drivers/net/z85230.c

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diff -u --recursive --new-file v2.1.120/linux/drivers/net/z85230.c linux/drivers/net/z85230.c
@@ -0,0 +1,1204 @@
+/*
+ *	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.
+ *
+ *	(c) Copyright 1998 Building Number Three Ltd
+ *
+ *	Development of this driver was funded by Equiinet Ltd
+ *			http://www.equiinet.com
+ *
+ *	ChangeLog:
+ *
+ *	Asynchronous mode dropped for 2.2. For 2.3 we will attempt the
+ *	unification of all the Z85x30 asynchronous drivers for real.
+ *
+ *	To Do:
+ *	
+ *	Finish DMA mode support.
+ *
+ *	Performance
+ *
+ *	Z85230:
+ *	Non DMA you want a 486DX50 or better to do 64Kbits. 9600 baud
+ *	X.25 is not unrealistic on all machines. DMA mode can in theory
+ *	handle T1/E1 quite nicely.
+ *
+ *	Z85C30:
+ *	64K will take DMA, 9600 baud X.25 should be ok.
+ *
+ *	Z8530:
+ *	Synchronous mode without DMA is unlikely to pass about 2400 baud.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <asm/dma.h>
+#include <asm/io.h>
+#define RT_LOCK
+#define RT_UNLOCK
+#include <asm/spinlock.h>
+
+#include "z85230.h"
+
+
+static spinlock_t z8530_buffer_lock = SPIN_LOCK_UNLOCKED;
+
+/*
+ *	Provided port access methods. The Comtrol SV11 requires no delays
+ *	between accesses and uses PC I/O. Some drivers may need a 5uS delay
+ */
+
+extern __inline__ int z8530_read_port(int p)
+{
+	u8 r=inb(Z8530_PORT_OF(p));
+	if(p&Z8530_PORT_SLEEP)	/* gcc should figure this out efficiently ! */
+		udelay(5);
+	return r;
+}
+
+extern __inline__ void z8530_write_port(int p, u8 d)
+{
+	outb(d,Z8530_PORT_OF(p));
+	if(p&Z8530_PORT_SLEEP)
+		udelay(5);
+}
+
+
+
+static void z8530_rx_done(struct z8530_channel *c);
+static void z8530_tx_done(struct z8530_channel *c);
+
+
+/*
+ *	Port accesses
+ */
+ 
+extern inline u8 read_zsreg(struct z8530_channel *c, u8 reg)
+{
+	u8 r;
+	unsigned long flags;
+	save_flags(flags);
+	cli();
+	if(reg)
+		z8530_write_port(c->ctrlio, reg);
+	r=z8530_read_port(c->ctrlio);
+	restore_flags(flags);
+	return r;
+}
+
+extern inline u8 read_zsdata(struct z8530_channel *c)
+{
+	u8 r;
+	r=z8530_read_port(c->dataio);
+	return r;
+}
+
+extern inline void write_zsreg(struct z8530_channel *c, u8 reg, u8 val)
+{
+	unsigned long flags;
+	save_flags(flags);
+	cli();
+	if(reg)
+		z8530_write_port(c->ctrlio, reg);
+	z8530_write_port(c->ctrlio, val);
+	restore_flags(flags);
+}
+
+extern inline void write_zsctrl(struct z8530_channel *c, u8 val)
+{
+	z8530_write_port(c->ctrlio, val);
+}
+
+extern inline void write_zsdata(struct z8530_channel *c, u8 val)
+{
+	z8530_write_port(c->dataio, val);
+}
+
+/*
+ *	Register loading parameters for a dead port
+ */
+ 
+u8 z8530_dead_port[]=
+{
+	255
+};
+
+EXPORT_SYMBOL(z8530_dead_port);
+
+/*
+ *	Register loading parameters for currently supported circuit types
+ */
+
+
+/*
+ *	Data clocked by telco end. This is the correct data for the UK
+ *	"kilostream" service, and most other similar services.
+ */
+ 
+u8 z8530_hdlc_kilostream[]=
+{
+	4,	SYNC_ENAB|SDLC|X1CLK,
+	2,	0,	/* No vector */
+	1,	0,
+	3,	ENT_HM|RxCRC_ENAB|Rx8,
+	5,	TxCRC_ENAB|RTS|TxENAB|Tx8|DTR,
+	9,	0,		/* Disable interrupts */
+	7,	FLAG,
+	10,	ABUNDER|MARKIDLE|NRZ|CRCPS,
+	11,	TCTRxCP,
+	14,	DISDPLL,
+	15,	DCDIE|SYNCIE|CTSIE|TxUIE|BRKIE,
+	1,	EXT_INT_ENAB|TxINT_ENAB|INT_ALL_Rx,
+	9,	NV|MIE|NORESET,
+	255
+};
+
+EXPORT_SYMBOL(z8530_hdlc_kilostream);
+
+/*
+ *	As above but for enhanced chips.
+ */
+
+u8 z8530_hdlc_kilostream_85230[]=
+{
+	4,	SYNC_ENAB|SDLC|X1CLK,
+	2,	0,	/* No vector */
+	1,	0,
+	3,	ENT_HM|RxCRC_ENAB|Rx8,
+	5,	TxCRC_ENAB|RTS|TxENAB|Tx8|DTR,
+	9,	0,		/* Disable interrupts */
+	7,	FLAG,
+	10,	ABUNDER|MARKIDLE|NRZ|CRCPS,
+	11,	TCTRxCP,
+	14,	DISDPLL,
+	15,	DCDIE|SYNCIE|CTSIE|TxUIE|BRKIE,
+	1,	EXT_INT_ENAB|TxINT_ENAB|INT_ALL_Rx,
+	9,	NV|MIE|NORESET,
+	23,	3,		/* Extended mode AUTO TX and EOM*/
+	31,	3,		/* Extended mode AUTO TX and EOM*/
+	
+	255
+};
+
+EXPORT_SYMBOL(z8530_hdlc_kilostream_85230);
+
+/*
+ *	Flush the FIFO
+ */
+ 
+static void z8530_flush_fifo(struct z8530_channel *c)
+{
+	read_zsreg(c, R1);
+	read_zsreg(c, R1);
+	read_zsreg(c, R1);
+	read_zsreg(c, R1);
+	if(c->dev->type==Z85230)
+	{
+		read_zsreg(c, R1);
+		read_zsreg(c, R1);
+		read_zsreg(c, R1);
+		read_zsreg(c, R1);
+	}
+}	
+
+/* Sets or clears DTR/RTS on the requested line */
+
+static void z8530_rtsdtr(struct z8530_channel *c, int set)
+{
+	if (set)
+		c->regs[5] |= (RTS | DTR);
+	else
+		c->regs[5] &= ~(RTS | DTR);
+	write_zsreg(c, R5, c->regs[5]);
+}
+
+/*
+ *	Receive handler. This is much like the async one but not quite the
+ *	same or as complex
+ *
+ *	Note: Its intended that this handler can easily be seperated from
+ *	the main code to run realtime. That'll be needed for some machines
+ *	(eg to ever clock 64kbits on a sparc ;)).
+ *
+ *	The RT_LOCK macros don't do anything now. Keep the code covered
+ *	by them as short as possible in all circumstances - clocks cost
+ *	baud. The interrupt handler is assumed to be atomic w.r.t. to
+ *	other code - this is true in the RT case too.
+ *
+ *	We only cover the sync cases for this. If you want 2Mbit async
+ *	do it yourself but consider medical assistance first.
+ *
+ *	This non DMA synchronous mode is portable code.
+ */
+ 
+static void z8530_rx(struct z8530_channel *c)
+{
+	u8 ch,stat;
+	 
+	while(1)
+	{
+		/* FIFO empty ? */
+		if(!(read_zsreg(c, R0)&1))
+			break;
+		ch=read_zsdata(c);
+		stat=read_zsreg(c, R1);
+	
+		/*
+		 *	Overrun ?
+		 */
+		if(c->count < c->max)
+		{
+			*c->dptr++=ch;
+			c->count++;
+		}
+
+		if(stat&END_FR)
+		{
+		
+			/*
+			 *	Error ?
+			 */
+			if(stat&(Rx_OVR|CRC_ERR))
+			{
+				/* Rewind the buffer and return */
+				if(c->skb)
+					c->dptr=c->skb->data;
+				c->count=0;
+				if(stat&Rx_OVR)
+				{
+					printk(KERN_WARNING "%s: overrun\n", c->dev->name);
+					c->rx_overrun++;
+				}
+				if(stat&CRC_ERR)
+				{
+					c->rx_crc_err++;
+					/* printk("crc error\n"); */
+				}
+				/* Shove the frame upstream */
+			}
+			else
+			{
+				z8530_rx_done(c);
+				write_zsctrl(c, RES_Rx_CRC);
+			}
+		}
+	}
+	/*
+	 *	Clear irq
+	 */
+	write_zsctrl(c, ERR_RES);
+	write_zsctrl(c, RES_H_IUS);
+}
+
+
+/*
+ *	Z8530 transmit interrupt handler
+ */
+ 
+static void z8530_tx(struct z8530_channel *c)
+{
+	while(c->txcount)
+	{
+		/* FIFO full ? */
+		if(!(read_zsreg(c, R0)&4))
+			break;
+		c->txcount--;
+		/*
+		 *	Shovel out the byte
+		 */
+		write_zsreg(c, R8, *c->tx_ptr++);
+		write_zsctrl(c, RES_H_IUS);
+		/* We are about to underflow */
+		if(c->txcount==0)
+		{
+			write_zsctrl(c, RES_EOM_L);
+			write_zsreg(c, R10, c->regs[10]&~ABUNDER);
+		}
+		return;
+	}
+	
+	/*
+	 *	End of frame TX - fire another one
+	 */
+	 
+	write_zsctrl(c, RES_Tx_P);
+
+	z8530_tx_done(c);	 
+/*	write_zsreg(c, R8, *c->tx_ptr++); */
+	write_zsctrl(c, RES_H_IUS);
+}
+
+static void z8530_status(struct z8530_channel *chan)
+{
+	u8 status=read_zsreg(chan, R0);
+	u8 altered=chan->status^status;
+	
+	chan->status=status;
+	
+	if(status&TxEOM)
+	{
+/*		printk("%s: Tx underrun.\n", chan->dev->name); */
+		write_zsctrl(chan, ERR_RES);
+		z8530_tx_done(chan);
+	}
+		
+	if(altered&DCD)
+	{
+		if(status&DCD)
+		{
+			printk(KERN_INFO "%s: DCD raised\n", chan->dev->name);
+			write_zsreg(chan, R3, chan->regs[3]|RxENABLE);
+		}
+		else
+		{
+			printk(KERN_INFO "%s: DCD lost\n", chan->dev->name);
+			write_zsreg(chan, R3, chan->regs[3]&~RxENABLE);
+			z8530_flush_fifo(chan);
+		}
+		
+	}	
+	write_zsctrl(chan, RES_EXT_INT);
+	write_zsctrl(chan, RES_H_IUS);
+}
+
+struct z8530_irqhandler z8530_sync=
+{
+	z8530_rx,
+	z8530_tx,
+	z8530_status
+};
+
+EXPORT_SYMBOL(z8530_sync);
+
+/*
+ *	Non bus mastering DMA interfaces for the Z8x30 devices. This
+ *	is really pretty PC specific.
+ */
+ 
+static void z8530_dma_rx(struct z8530_channel *chan)
+{
+	if(chan->rxdma_on)
+	{
+		/* Special condition check only */
+		u8 status=read_zsreg(chan, R1);
+		if(status&END_FR)
+		{
+			z8530_rx_done(chan);	/* Fire up the next one */
+		}		
+		write_zsctrl(chan, ERR_RES);
+		write_zsctrl(chan, RES_H_IUS);
+	}
+	else
+	{
+		/* DMA is off right now, drain the slow way */
+		z8530_rx(chan);
+	}	
+}
+
+static void z8530_dma_tx(struct z8530_channel *chan)
+{
+	if(!chan->txdma_on)
+	{
+		z8530_tx(chan);
+		return;
+	}
+	/* This shouldnt occur in DMA mode */
+	printk(KERN_ERR "DMA tx ??\n");
+	z8530_tx(chan);
+}
+
+static void z8530_dma_status(struct z8530_channel *chan)
+{
+	u8 status=read_zsreg(chan, R0);
+	u8 altered=chan->status^status;
+	
+	chan->status=status;
+
+	if(chan->txdma_on)
+	{
+		if(status&TxEOM)
+		{
+			/* Transmit underrun */
+			disable_dma(chan->txdma);
+			clear_dma_ff(chan->txdma);	
+			chan->txdma_on=0;
+			z8530_tx_done(chan);
+		}
+	}
+	if(altered&DCD)
+	{
+		if(status&DCD)
+		{
+			printk(KERN_INFO "%s: DCD raised\n", chan->dev->name);
+			write_zsreg(chan, R3, chan->regs[3]|RxENABLE);
+		}
+		else
+		{
+			printk(KERN_INFO "%s:DCD lost\n", chan->dev->name);
+			write_zsreg(chan, R3, chan->regs[3]&~RxENABLE);
+			z8530_flush_fifo(chan);
+		}
+	}	
+	write_zsctrl(chan, RES_EXT_INT);
+	write_zsctrl(chan, RES_H_IUS);
+}
+
+struct z8530_irqhandler z8530_dma_sync=
+{
+	z8530_dma_rx,
+	z8530_dma_tx,
+	z8530_dma_status
+};
+
+EXPORT_SYMBOL(z8530_dma_sync);
+
+/*
+ *	Interrupt vectors for a Z8530 that is in 'parked' mode.
+ *	For machines with PCI Z85x30 cards, or level triggered interrupts
+ *	(eg the MacII) we must clear the interrupt cause or die.
+ */
+
+
+static void z8530_rx_clear(struct z8530_channel *c)
+{
+	/*
+	 *	Data and status bytes
+	 */
+	u8 stat;
+
+	read_zsdata(c);
+	stat=read_zsreg(c, R1);
+	
+	if(stat&END_FR)
+		write_zsctrl(c, RES_Rx_CRC);
+	/*
+	 *	Clear irq
+	 */
+	write_zsctrl(c, ERR_RES);
+	write_zsctrl(c, RES_H_IUS);
+}
+
+static void z8530_tx_clear(struct z8530_channel *c)
+{
+	write_zsctrl(c, RES_Tx_P);
+	write_zsctrl(c, RES_H_IUS);
+}
+
+static void z8530_status_clear(struct z8530_channel *chan)
+{
+	u8 status=read_zsreg(chan, R0);
+	if(status&TxEOM)
+		write_zsctrl(chan, ERR_RES);
+	write_zsctrl(chan, RES_EXT_INT);
+	write_zsctrl(chan, RES_H_IUS);
+}
+
+struct z8530_irqhandler z8530_nop=
+{
+	z8530_rx_clear,
+	z8530_tx_clear,
+	z8530_status_clear
+};
+
+
+EXPORT_SYMBOL(z8530_nop);
+
+/*
+ *	A Z85[2]30 device has stuck its hand in the air for attention
+ */
+
+void z8530_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct z8530_dev *dev=dev_id;
+	u8 intr;
+	static volatile int locker=0;
+	int work=0;
+	
+	if(locker)
+	{
+		printk(KERN_ERR "IRQ re-enter\n");
+		return;
+	}
+	locker=1;
+	
+	while(++work<5000)
+	{
+		struct z8530_irqhandler *irqs=dev->chanA.irqs;
+		
+		intr = read_zsreg(&dev->chanA, R3);
+		if(!(intr & (CHARxIP|CHATxIP|CHAEXT|CHBRxIP|CHBTxIP|CHBEXT)))
+			break;
+	
+		/* This holds the IRQ status. On the 8530 you must read it from chan 
+		   A even though it applies to the whole chip */
+		
+		/* Now walk the chip and see what it is wanting - it may be
+		   an IRQ for someone else remember */
+		   
+		if(intr & (CHARxIP|CHATxIP|CHAEXT))
+		{
+			if(intr&CHARxIP)
+				irqs->rx(&dev->chanA);
+			if(intr&CHATxIP)
+				irqs->tx(&dev->chanA);
+			if(intr&CHAEXT)
+				irqs->status(&dev->chanA);
+		}
+
+		irqs=dev->chanB.irqs;
+
+		if(intr & (CHBRxIP|CHBTxIP|CHBEXT))
+		{
+			if(intr&CHBRxIP)
+				irqs->rx(&dev->chanB);
+			if(intr&CHBTxIP)
+				irqs->tx(&dev->chanB);
+			if(intr&CHBEXT)
+				irqs->status(&dev->chanB);
+		}
+	}
+	if(work==200)
+		printk(KERN_ERR "%s: interrupt jammed - abort(0x%X)!\n", dev->name, intr);
+	/* Ok all done */
+	locker=0;
+}
+
+EXPORT_SYMBOL(z8530_interrupt);
+
+static char reg_init[16]=
+{
+	0,0,0,0,
+	0,0,0,0,
+	0,0,0,0,
+	0x55,0,0,0
+};
+
+
+int z8530_sync_open(struct device *dev, struct z8530_channel *c)
+{
+	c->sync = 1;
+	c->mtu = dev->mtu;
+	c->count = 0;
+	c->skb = NULL;
+	c->skb2 = NULL;
+	c->irqs = &z8530_sync;
+	/* This loads the double buffer up */
+	z8530_rx_done(c);	/* Load the frame ring */
+	z8530_rx_done(c);	/* Load the backup frame */
+	z8530_rtsdtr(c,1);
+	write_zsreg(c, R3, c->regs[R3]|RxENABLE);
+	return 0;
+}
+
+
+EXPORT_SYMBOL(z8530_sync_open);
+
+int z8530_sync_close(struct device *dev, struct z8530_channel *c)
+{
+	u8 chk;
+	c->irqs = &z8530_nop;
+	c->max = 0;
+	c->sync = 0;
+	
+	chk=read_zsreg(c,R0);
+	write_zsreg(c, R3, c->regs[R3]);
+	z8530_rtsdtr(c,0);
+	return 0;
+}
+
+EXPORT_SYMBOL(z8530_sync_close);
+
+int z8530_sync_dma_open(struct device *dev, struct z8530_channel *c)
+{
+	c->sync = 1;
+	c->mtu = dev->mtu;
+	c->count = 0;
+	c->skb = NULL;
+	c->skb2 = NULL;
+	/*
+	 *	Load the DMA interfaces up
+	 */
+	c->rxdma_on = 0;
+	c->txdma_on = 0;
+	
+	/*
+	 *	Allocate the DMA flip buffers
+	 */
+	 
+	c->rx_buf[0]=kmalloc(c->mtu, GFP_KERNEL|GFP_DMA);
+	if(c->rx_buf[0]==NULL)
+		return -ENOBUFS;
+	c->rx_buf[1]=kmalloc(c->mtu, GFP_KERNEL|GFP_DMA);
+	if(c->rx_buf[1]==NULL)
+	{
+		kfree(c->rx_buf[0]);
+		c->rx_buf[0]=NULL;
+		return -ENOBUFS;
+	}
+	
+	c->tx_dma_buf[0]=kmalloc(c->mtu, GFP_KERNEL|GFP_DMA);
+	if(c->tx_dma_buf[0]==NULL)
+	{
+		kfree(c->rx_buf[0]);
+		kfree(c->rx_buf[1]);
+		c->rx_buf[0]=NULL;
+		return -ENOBUFS;
+	}
+	c->tx_dma_buf[1]=kmalloc(c->mtu, GFP_KERNEL|GFP_DMA);
+	if(c->tx_dma_buf[1]==NULL)
+	{
+		kfree(c->tx_dma_buf[0]);
+		kfree(c->rx_buf[0]);
+		kfree(c->rx_buf[1]);
+		c->rx_buf[0]=NULL;
+		c->rx_buf[1]=NULL;
+		c->tx_dma_buf[0]=NULL;
+		return -ENOBUFS;
+	}
+	c->tx_dma_used=0;
+	c->dma_num=0;
+	c->dma_ready=1;
+	
+	/*
+	 *	Enable DMA control mode
+	 */
+	 
+	c->regs[R1]|= WT_RDY_RT|WT_FN_RDYFN;
+	c->regs[R1]|= INT_ERR_Rx;
+	write_zsreg(c, R1, c->regs[R1]);
+	c->regs[R1]|= WT_RDY_ENAB;
+	write_zsreg(c, R1, c->regs[R1]);            
+	c->regs[R14]|= DTRREQ;
+	write_zsreg(c, R14, c->regs[R14]);     
+	
+	/*
+	 *	DMA interrupts
+	 */
+	 
+	/*
+	 *	Set up the DMA configuration
+	 */	
+	 
+	disable_dma(c->rxdma);
+	clear_dma_ff(c->rxdma);
+	set_dma_mode(c->rxdma, DMA_MODE_READ);
+	set_dma_addr(c->rxdma, virt_to_bus(c->rx_buf[0]));
+	set_dma_count(c->rxdma, c->mtu);
+	enable_dma(c->rxdma);
+
+	disable_dma(c->txdma);
+	clear_dma_ff(c->txdma);
+	set_dma_mode(c->txdma, DMA_MODE_WRITE);
+	disable_dma(c->txdma);
+	
+	/*
+	 *	Select the DMA interrupt handlers
+	 */
+
+	c->rxdma_on = 1;
+	c->txdma_on = 1;
+	c->tx_dma_used = 1;
+	 
+	c->irqs = &z8530_dma_sync;
+	z8530_rtsdtr(c,1);
+	write_zsreg(c, R3, c->regs[R3]|RxENABLE);
+	return 0;
+}
+
+EXPORT_SYMBOL(z8530_sync_dma_open);
+
+int z8530_sync_dma_close(struct device *dev, struct z8530_channel *c)
+{
+	u8 chk;
+	c->irqs = &z8530_nop;
+	c->max = 0;
+	c->sync = 0;
+	
+	/*
+	 *	Disable the PC DMA channels
+	 */
+	 
+	disable_dma(c->rxdma);
+	clear_dma_ff(c->rxdma);
+	c->rxdma_on = 0;
+	disable_dma(c->txdma);
+	clear_dma_ff(c->txdma);
+	c->txdma_on = 0;
+	c->tx_dma_used = 0;
+
+	/*
+	 *	Disable DMA control mode
+	 */
+	 
+	c->regs[R1]&= ~WT_RDY_ENAB;
+	write_zsreg(c, R1, c->regs[R1]);            
+	c->regs[R1]&= ~(WT_RDY_RT|WT_FN_RDYFN|INT_ERR_Rx);
+	c->regs[R1]|= INT_ALL_Rx;
+	write_zsreg(c, R1, c->regs[R1]);
+	c->regs[R14]&= ~DTRREQ;
+	write_zsreg(c, R14, c->regs[R14]);   
+	
+	if(c->rx_buf[0])
+	{
+		kfree(c->rx_buf[0]);
+		c->rx_buf[0]=NULL;
+	}
+	if(c->rx_buf[1])
+	{
+		kfree(c->rx_buf[1]);
+		c->rx_buf[1]=NULL;
+	}
+	if(c->tx_dma_buf[0])
+	{
+		kfree(c->tx_dma_buf[0]);
+		c->tx_dma_buf[0]=NULL;
+	}
+	if(c->tx_dma_buf[1])
+	{
+		kfree(c->tx_dma_buf[1]);
+		c->tx_dma_buf[1]=NULL;
+	}
+	chk=read_zsreg(c,R0);
+	write_zsreg(c, R3, c->regs[R3]);
+	z8530_rtsdtr(c,0);
+	return 0;
+}
+
+EXPORT_SYMBOL(z8530_sync_dma_close);
+
+/*
+ *	Describe a Z8530 in a standard format. We must pass the I/O as
+ *	the port offset isnt predictable. The main reason for this function
+ *	is to try and get a common format of report.
+ */
+
+static char *z8530_type_name[]={
+	"Z8530",
+	"Z85C30",
+	"Z85230"
+};
+
+void z8530_describe(struct z8530_dev *dev, char *mapping, int io)
+{
+	printk(KERN_INFO "%s: %s found at %s 0x%X, IRQ %d.\n",
+		dev->name, 
+		z8530_type_name[dev->type],
+		mapping,
+		io,
+		dev->irq);
+}
+
+EXPORT_SYMBOL(z8530_describe);
+
+/*
+ *	Configure up a Z8530
+ */
+
+ 
+int z8530_init(struct z8530_dev *dev)
+{
+	/* NOP the interrupt handlers first - we might get a
+	   floating IRQ transition when we reset the chip */
+	dev->chanA.irqs=&z8530_nop;
+	dev->chanB.irqs=&z8530_nop;
+	/* Reset the chip */
+	write_zsreg(&dev->chanA, R9, 0xC0);
+	udelay(100);
+	/* Now check its valid */
+	write_zsreg(&dev->chanA, R12, 0xAA);
+	if(read_zsreg(&dev->chanA, R12)!=0xAA)
+		return -ENODEV;
+	write_zsreg(&dev->chanA, R12, 0x55);
+	if(read_zsreg(&dev->chanA, R12)!=0x55)
+		return -ENODEV;
+		
+	dev->type=Z8530;
+	
+	/*
+	 *	See the application note.
+	 */
+	 
+	write_zsreg(&dev->chanA, R15, 0x01);
+	
+	/*
+	 *	If we can set the low bit of R15 then
+	 *	the chip is enhanced.
+	 */
+	 
+	if(read_zsreg(&dev->chanA, R15)==0x01)
+	{
+		/* This C30 versus 230 detect is from Klaus Kudielka's dmascc */
+		/* Put a char in the fifo */
+		write_zsreg(&dev->chanA, R8, 0);
+		if(read_zsreg(&dev->chanA, R0)&Tx_BUF_EMP)
+			dev->type = Z85230;	/* Has a FIFO */
+		else
+			dev->type = Z85C30;	/* Z85C30, 1 byte FIFO */
+	}
+		
+	/*
+	 *	The code assumes R7' and friends are
+	 *	off. Use write_zsext() for these and keep
+	 *	this bit clear.
+	 */
+	 
+	write_zsreg(&dev->chanA, R15, 0);
+		
+	/*
+	 *	At this point it looks like the chip is behaving
+	 */
+	 
+	memcpy(dev->chanA.regs, reg_init, 16);
+	memcpy(dev->chanB.regs, reg_init ,16);
+	
+	return 0;
+}
+
+
+EXPORT_SYMBOL(z8530_init);
+
+int z8530_shutdown(struct z8530_dev *dev)
+{
+	/* Reset the chip */
+	dev->chanA.irqs=&z8530_nop;
+	dev->chanB.irqs=&z8530_nop;
+	write_zsreg(&dev->chanA, R9, 0xC0);
+	udelay(100);
+	return 0;
+}
+
+EXPORT_SYMBOL(z8530_shutdown);
+
+/*
+ *	Load a Z8530 channel up from the system data
+ *	We use +16 to indicate the 'prime' registers
+ */
+
+int z8530_channel_load(struct z8530_channel *c, u8 *rtable)
+{
+	while(*rtable!=255)
+	{
+		int reg=*rtable++;
+		if(reg>0x0F)
+			write_zsreg(c, R15, c->regs[15]|1);
+		write_zsreg(c, reg&0x0F, *rtable);
+		if(reg>0x0F)
+			write_zsreg(c, R15, c->regs[15]&~1);
+		c->regs[reg]=*rtable++;
+	}
+	c->rx_function=z8530_null_rx;
+	c->skb=NULL;
+	c->tx_skb=NULL;
+	c->tx_next_skb=NULL;
+	c->mtu=1500;
+	c->max=0;
+	c->count=0;
+	c->status=0;	/* Fixme - check DCD now */
+	c->sync=1;
+	write_zsreg(c, R3, c->regs[R3]|RxENABLE);
+	return 0;
+}
+
+EXPORT_SYMBOL(z8530_channel_load);
+
+
+/*
+ *	Higher level shovelling - transmit chains
+ */
+
+static void z8530_tx_begin(struct z8530_channel *c)
+{
+	unsigned long flags;
+	if(c->tx_skb)
+		return;
+		
+	c->tx_skb=c->tx_next_skb;
+	c->tx_next_skb=NULL;
+	c->tx_ptr=c->tx_next_ptr;
+	
+	mark_bh(NET_BH);
+	if(c->tx_skb==NULL)
+	{
+		/* Idle on */
+		disable_dma(c->txdma);
+		c->txcount=0;
+	}
+	else
+	{
+		c->tx_ptr=c->tx_next_ptr;
+		c->txcount=c->tx_skb->len;
+		
+		
+		if(c->tx_dma_used)
+		{
+			/*
+			 *	FIXME. DMA is broken for the non 85230,
+			 *	on the older parts we need to set a flag and
+			 *	wait for a further TX interrupt to fire this
+			 *	stage off	
+			 */
+			disable_dma(c->txdma);
+			clear_dma_ff(c->txdma);
+			set_dma_addr(c->txdma, virt_to_bus(c->tx_ptr));
+			set_dma_count(c->txdma, c->txcount);
+			enable_dma(c->txdma);
+			write_zsreg(c, R5, c->regs[R5]|TxENAB);
+		}
+		else
+		{
+			save_flags(flags);
+			cli();
+			/* ABUNDER off */
+			write_zsreg(c, R10, c->regs[10]);
+			write_zsctrl(c, RES_Tx_CRC);
+			write_zsctrl(c, RES_EOM_L);
+	
+			while(c->txcount && (read_zsreg(c,R0)&Tx_BUF_EMP))
+			{		
+				write_zsreg(c, R8, *c->tx_ptr++);
+				c->txcount--;
+			}
+			restore_flags(flags);
+		}
+	}
+}
+ 
+ 
+static void z8530_tx_done(struct z8530_channel *c)
+{
+	unsigned long flags;
+	struct sk_buff *skb;
+
+	spin_lock_irqsave(&z8530_buffer_lock, flags);
+	c->netdevice->tbusy=0;
+	/* Can't happen */
+	if(c->tx_skb==NULL)
+	{
+		spin_unlock_irqrestore(&z8530_buffer_lock, flags);
+		printk(KERN_WARNING "%s: spurious tx done\n", c->dev->name);
+		return;
+	}
+	skb=c->tx_skb;
+	c->tx_skb=NULL;
+	z8530_tx_begin(c);
+	spin_unlock_irqrestore(&z8530_buffer_lock, flags);
+	dev_kfree_skb(skb);
+}
+
+/*
+ *	Higher level shovelling - receive chains
+ */
+ 
+void z8530_null_rx(struct z8530_channel *c, struct sk_buff *skb)
+{
+	kfree_skb(skb);
+}
+
+EXPORT_SYMBOL(z8530_null_rx);
+
+static void z8530_rx_done(struct z8530_channel *c)
+{
+	struct sk_buff *skb;
+	int ct;
+	
+	/*
+	 *	Is our receive engine in DMA mode
+	 */
+	 
+	if(c->rxdma_on)
+	{
+		/*
+		 *	Save the ready state and the buffer currently
+		 *	being used as the DMA target
+		 */
+		int ready=c->dma_ready;
+		char *rxb=c->rx_buf[c->dma_num];
+		
+		/*
+		 *	Complete this DMA. Neccessary to find the length
+		 */		
+		disable_dma(c->rxdma);
+		clear_dma_ff(c->rxdma);
+		c->rxdma_on=0;
+		ct=c->mtu-get_dma_residue(c->rxdma)-4;
+		if(ct<0)
+			ct=2;	/* Shit happens.. */
+		c->dma_ready=0;
+		
+		/*
+		 *	Normal case: the other slot is free, start the next DMA
+		 *	into it immediately.
+		 */
+		 
+		if(ready)
+		{
+			c->dma_num^=1;
+			set_dma_mode(c->rxdma, DMA_MODE_READ);
+			set_dma_addr(c->rxdma, virt_to_bus(c->rx_buf[c->dma_num]));
+			set_dma_count(c->rxdma, c->mtu);
+			c->rxdma_on = 1;
+			enable_dma(c->rxdma);
+		}
+		else
+			/* Can't occur as we dont reenable the DMA irq until
+			   after the flip is done */
+			printk("DMA flip overrun!\n");
+		
+		/*
+		 *	Shove the old buffer into an sk_buff. We can't DMA
+		 *	directly into one on a PC - it might be above the 16Mb
+		 *	boundary. Optimisation - we could check to see if we
+		 *	can avoid the copy. Optimisation 2 - make the memcpy
+		 *	a copychecksum.
+		 */
+		 
+		skb=dev_alloc_skb(ct);
+		if(skb==NULL)
+			printk("%s: Memory squeeze.\n", c->netdevice->name);
+		else
+		{
+			skb_put(skb, ct);
+			memcpy(skb->data, rxb, ct);
+			skb_pull(skb,2);
+		}
+		c->dma_ready=1;
+	}
+	else
+	{
+		RT_LOCK;	
+		skb=c->skb;
+		
+		/*
+		 *	The game we play for non DMA is similar. We want to
+		 *	get the controller set up for the next packet as fast
+		 *	as possible. We potentially only have one byte + the
+		 *	fifo length for this. Thus we want to flip to the new
+		 *	buffer and then mess around copying and allocating
+		 *	things. For the current case it doesn't matter but
+		 *	if you build a system where the sync irq isnt blocked
+		 *	by the kernel IRQ disable then you need only block the
+		 *	sync IRQ for the RT_LOCK area.
+		 *	
+		 */
+		ct=c->count;
+		
+		c->skb = c->skb2;
+		c->count = 0;
+		c->max = c->mtu;
+		if(c->skb)
+		{
+			c->dptr = c->skb->data;
+			c->max = c->mtu;
+		}
+		else
+		{
+			c->count= 0;
+			c->max = 0;
+		}
+		RT_UNLOCK;
+
+		c->skb2 = dev_alloc_skb(c->mtu);
+		if(c->skb2==NULL)
+			printk(KERN_WARNING "%s: memory squeeze.\n",
+				c->netdevice->name);
+		else
+		{
+			skb_put(c->skb2,c->mtu);
+		}
+	}
+	/*
+	 *	If we received a frame we must now process it.
+	 */
+	if(skb)
+	{
+		skb_trim(skb, ct);
+		c->rx_function(c,skb);
+	}
+	else
+		printk("Lost a frame\n");
+}
+
+
+/*
+ *	Queue a packet for transmission. Because we have rather
+ *	hard to hit interrupt latencies for the Z85230 per packet 
+ *	even in DMA mode we do the flip to DMA buffer if needed here
+ *	not in the IRQ.
+ */
+
+int z8530_queue_xmit(struct z8530_channel *c, struct sk_buff *skb)
+{
+	unsigned long flags;
+	if(c->tx_next_skb)
+	{
+		skb->dev->tbusy=1;
+		return 1;
+	}
+	
+	/* PC SPECIFIC - DMA limits */
+	
+	/*
+	 *	If we will DMA the transmit and its gone over the ISA bus
+	 *	limit, then copy to the flip buffer
+	 */
+	 
+	if(c->dma_tx && (unsigned long)(virt_to_bus(skb->data+skb->len))>=16*1024*1024)
+	{
+		/* 
+		 *	Send the flip buffer, and flip the flippy bit.
+		 *	We don't care which is used when just so long as
+		 *	we never use the same buffer twice in a row. Since
+		 *	only one buffer can be going out at a time the other
+		 *	has to be safe.
+		 */
+		c->tx_next_ptr=c->tx_dma_buf[c->tx_dma_used];
+		c->tx_dma_used^=1;	/* Flip temp buffer */
+		memcpy(c->tx_next_ptr, skb->data, skb->len);
+	}
+	else
+		c->tx_next_ptr=skb->data;	
+	RT_LOCK;
+	c->tx_next_skb=skb;
+	RT_UNLOCK;
+	
+	spin_lock_irqsave(&z8530_buffer_lock, flags);
+	z8530_tx_begin(c);
+	spin_unlock_irqrestore(&z8530_buffer_lock, flags);
+	return 0;
+}
+
+EXPORT_SYMBOL(z8530_queue_xmit);
+
+struct net_device_stats *z8530_get_stats(struct z8530_channel *c)
+{
+	return &c->stats;
+}
+
+EXPORT_SYMBOL(z8530_get_stats);
+
+#ifdef MODULE
+
+/*
+ *	Module support
+ */
+ 
+int init_module(void)
+{
+	printk(KERN_INFO "Generic Z85C30/Z85230 interface driver v0.02\n");
+	return 0;
+}
+
+void cleanup_module(void)
+{
+}
+
+#endif
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