diff options
Diffstat (limited to 'kernel/drivers/net/wan/z85230.c')
| -rw-r--r-- | kernel/drivers/net/wan/z85230.c | 1795 |
1 files changed, 1795 insertions, 0 deletions
diff --git a/kernel/drivers/net/wan/z85230.c b/kernel/drivers/net/wan/z85230.c new file mode 100644 index 000000000..feacc3b99 --- /dev/null +++ b/kernel/drivers/net/wan/z85230.c @@ -0,0 +1,1795 @@ +/* + * 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 Alan Cox <alan@lxorguk.ukuu.org.uk> + * (c) Copyright 2000, 2001 Red Hat Inc + * + * Development of this driver was funded by Equiinet Ltd + * http://www.equiinet.com + * + * ChangeLog: + * + * Asynchronous mode dropped for 2.2. For 2.5 we will attempt the + * unification of all the Z85x30 asynchronous drivers for real. + * + * DMA now uses get_free_page as kmalloc buffers may span a 64K + * boundary. + * + * Modified for SMP safety and SMP locking by Alan Cox + * <alan@lxorguk.ukuu.org.uk> + * + * 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. In practice the limit seems to be about + * 512Kbit->1Mbit depending on motherboard. + * + * Z85C30: + * 64K will take DMA, 9600 baud X.25 should be ok. + * + * Z8530: + * Synchronous mode without DMA is unlikely to pass about 2400 baud. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#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/hdlc.h> +#include <linux/ioport.h> +#include <linux/init.h> +#include <linux/gfp.h> +#include <asm/dma.h> +#include <asm/io.h> +#define RT_LOCK +#define RT_UNLOCK +#include <linux/spinlock.h> + +#include "z85230.h" + + +/** + * z8530_read_port - Architecture specific interface function + * @p: port to read + * + * Provided port access methods. The Comtrol SV11 requires no delays + * between accesses and uses PC I/O. Some drivers may need a 5uS delay + * + * In the longer term this should become an architecture specific + * section so that this can become a generic driver interface for all + * platforms. For now we only handle PC I/O ports with or without the + * dread 5uS sanity delay. + * + * The caller must hold sufficient locks to avoid violating the horrible + * 5uS delay rule. + */ + +static inline int z8530_read_port(unsigned long p) +{ + u8 r=inb(Z8530_PORT_OF(p)); + if(p&Z8530_PORT_SLEEP) /* gcc should figure this out efficiently ! */ + udelay(5); + return r; +} + +/** + * z8530_write_port - Architecture specific interface function + * @p: port to write + * @d: value to write + * + * Write a value to a port with delays if need be. Note that the + * caller must hold locks to avoid read/writes from other contexts + * violating the 5uS rule + * + * In the longer term this should become an architecture specific + * section so that this can become a generic driver interface for all + * platforms. For now we only handle PC I/O ports with or without the + * dread 5uS sanity delay. + */ + + +static inline void z8530_write_port(unsigned long 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); + + +/** + * read_zsreg - Read a register from a Z85230 + * @c: Z8530 channel to read from (2 per chip) + * @reg: Register to read + * FIXME: Use a spinlock. + * + * Most of the Z8530 registers are indexed off the control registers. + * A read is done by writing to the control register and reading the + * register back. The caller must hold the lock + */ + +static inline u8 read_zsreg(struct z8530_channel *c, u8 reg) +{ + if(reg) + z8530_write_port(c->ctrlio, reg); + return z8530_read_port(c->ctrlio); +} + +/** + * read_zsdata - Read the data port of a Z8530 channel + * @c: The Z8530 channel to read the data port from + * + * The data port provides fast access to some things. We still + * have all the 5uS delays to worry about. + */ + +static inline u8 read_zsdata(struct z8530_channel *c) +{ + u8 r; + r=z8530_read_port(c->dataio); + return r; +} + +/** + * write_zsreg - Write to a Z8530 channel register + * @c: The Z8530 channel + * @reg: Register number + * @val: Value to write + * + * Write a value to an indexed register. The caller must hold the lock + * to honour the irritating delay rules. We know about register 0 + * being fast to access. + * + * Assumes c->lock is held. + */ +static inline void write_zsreg(struct z8530_channel *c, u8 reg, u8 val) +{ + if(reg) + z8530_write_port(c->ctrlio, reg); + z8530_write_port(c->ctrlio, val); + +} + +/** + * write_zsctrl - Write to a Z8530 control register + * @c: The Z8530 channel + * @val: Value to write + * + * Write directly to the control register on the Z8530 + */ + +static inline void write_zsctrl(struct z8530_channel *c, u8 val) +{ + z8530_write_port(c->ctrlio, val); +} + +/** + * write_zsdata - Write to a Z8530 control register + * @c: The Z8530 channel + * @val: Value to write + * + * Write directly to the data register on the Z8530 + */ + + +static 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 */ + 6, 0xFF, + 7, FLAG, + 10, ABUNDER|NRZ|CRCPS,/*MARKIDLE ??*/ + 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 */ + 6, 0xFF, + 7, FLAG, + 10, ABUNDER|NRZ|CRCPS, /* MARKIDLE?? */ + 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*/ + + 255 +}; + +EXPORT_SYMBOL(z8530_hdlc_kilostream_85230); + +/** + * z8530_flush_fifo - Flush on chip RX FIFO + * @c: Channel to flush + * + * Flush the receive FIFO. There is no specific option for this, we + * blindly read bytes and discard them. Reading when there is no data + * is harmless. The 8530 has a 4 byte FIFO, the 85230 has 8 bytes. + * + * All locking is handled for the caller. On return data may still be + * present if it arrived during the flush. + */ + +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); + } +} + +/** + * z8530_rtsdtr - Control the outgoing DTS/RTS line + * @c: The Z8530 channel to control; + * @set: 1 to set, 0 to clear + * + * Sets or clears DTR/RTS on the requested line. All locking is handled + * by the caller. For now we assume all boards use the actual RTS/DTR + * on the chip. Apparently one or two don't. We'll scream about them + * later. + */ + +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]); +} + +/** + * z8530_rx - Handle a PIO receive event + * @c: Z8530 channel to process + * + * Receive handler for receiving in PIO mode. This is much like the + * async one but not quite the same or as complex + * + * Note: Its intended that this handler can easily be separated 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. The DMA mode assumes PCI like + * ISA DMA + * + * Called with the device lock held + */ + +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) + { + pr_warn("%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 + { + /* + * Drop the lock for RX processing, or + * there are deadlocks + */ + z8530_rx_done(c); + write_zsctrl(c, RES_Rx_CRC); + } + } + } + /* + * Clear irq + */ + write_zsctrl(c, ERR_RES); + write_zsctrl(c, RES_H_IUS); +} + + +/** + * z8530_tx - Handle a PIO transmit event + * @c: Z8530 channel to process + * + * Z8530 transmit interrupt handler for the PIO mode. The basic + * idea is to attempt to keep the FIFO fed. We fill as many bytes + * in as possible, its quite possible that we won't keep up with the + * data rate otherwise. + */ + +static void z8530_tx(struct z8530_channel *c) +{ + while(c->txcount) { + /* FIFO full ? */ + if(!(read_zsreg(c, R0)&4)) + return; + 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); + } + } + + + /* + * End of frame TX - fire another one + */ + + write_zsctrl(c, RES_Tx_P); + + z8530_tx_done(c); + write_zsctrl(c, RES_H_IUS); +} + +/** + * z8530_status - Handle a PIO status exception + * @chan: Z8530 channel to process + * + * A status event occurred in PIO synchronous mode. There are several + * reasons the chip will bother us here. A transmit underrun means we + * failed to feed the chip fast enough and just broke a packet. A DCD + * change is a line up or down. + */ + +static void z8530_status(struct z8530_channel *chan) +{ + u8 status, altered; + + status = read_zsreg(chan, R0); + altered = chan->status ^ status; + + chan->status = status; + + if (status & TxEOM) { +/* printk("%s: Tx underrun.\n", chan->dev->name); */ + chan->netdevice->stats.tx_fifo_errors++; + write_zsctrl(chan, ERR_RES); + z8530_tx_done(chan); + } + + if (altered & chan->dcdcheck) + { + if (status & chan->dcdcheck) { + pr_info("%s: DCD raised\n", chan->dev->name); + write_zsreg(chan, R3, chan->regs[3] | RxENABLE); + if (chan->netdevice) + netif_carrier_on(chan->netdevice); + } else { + pr_info("%s: DCD lost\n", chan->dev->name); + write_zsreg(chan, R3, chan->regs[3] & ~RxENABLE); + z8530_flush_fifo(chan); + if (chan->netdevice) + netif_carrier_off(chan->netdevice); + } + + } + 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); + +/** + * z8530_dma_rx - Handle a DMA RX event + * @chan: Channel to handle + * + * Non bus mastering DMA interfaces for the Z8x30 devices. This + * is really pretty PC specific. The DMA mode means that most receive + * events are handled by the DMA hardware. We get a kick here only if + * a frame ended. + */ + +static void z8530_dma_rx(struct z8530_channel *chan) +{ + if(chan->rxdma_on) + { + /* Special condition check only */ + u8 status; + + read_zsreg(chan, R7); + read_zsreg(chan, R6); + + 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); + } +} + +/** + * z8530_dma_tx - Handle a DMA TX event + * @chan: The Z8530 channel to handle + * + * We have received an interrupt while doing DMA transmissions. It + * shouldn't happen. Scream loudly if it does. + */ + +static void z8530_dma_tx(struct z8530_channel *chan) +{ + if(!chan->dma_tx) + { + pr_warn("Hey who turned the DMA off?\n"); + z8530_tx(chan); + return; + } + /* This shouldn't occur in DMA mode */ + pr_err("DMA tx - bogus event!\n"); + z8530_tx(chan); +} + +/** + * z8530_dma_status - Handle a DMA status exception + * @chan: Z8530 channel to process + * + * A status event occurred on the Z8530. We receive these for two reasons + * when in DMA mode. Firstly if we finished a packet transfer we get one + * and kick the next packet out. Secondly we may see a DCD change. + * + */ + +static void z8530_dma_status(struct z8530_channel *chan) +{ + u8 status, altered; + + status=read_zsreg(chan, R0); + altered=chan->status^status; + + chan->status=status; + + + if(chan->dma_tx) + { + if(status&TxEOM) + { + unsigned long flags; + + flags=claim_dma_lock(); + disable_dma(chan->txdma); + clear_dma_ff(chan->txdma); + chan->txdma_on=0; + release_dma_lock(flags); + z8530_tx_done(chan); + } + } + + if (altered & chan->dcdcheck) + { + if (status & chan->dcdcheck) { + pr_info("%s: DCD raised\n", chan->dev->name); + write_zsreg(chan, R3, chan->regs[3] | RxENABLE); + if (chan->netdevice) + netif_carrier_on(chan->netdevice); + } else { + pr_info("%s: DCD lost\n", chan->dev->name); + write_zsreg(chan, R3, chan->regs[3] & ~RxENABLE); + z8530_flush_fifo(chan); + if (chan->netdevice) + netif_carrier_off(chan->netdevice); + } + } + + write_zsctrl(chan, RES_EXT_INT); + write_zsctrl(chan, RES_H_IUS); +} + +static struct z8530_irqhandler z8530_dma_sync = { + z8530_dma_rx, + z8530_dma_tx, + z8530_dma_status +}; + +static struct z8530_irqhandler z8530_txdma_sync = { + z8530_rx, + z8530_dma_tx, + z8530_dma_status +}; + +/** + * z8530_rx_clear - Handle RX events from a stopped chip + * @c: Z8530 channel to shut up + * + * Receive 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); +} + +/** + * z8530_tx_clear - Handle TX events from a stopped chip + * @c: Z8530 channel to shut up + * + * Transmit 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_tx_clear(struct z8530_channel *c) +{ + write_zsctrl(c, RES_Tx_P); + write_zsctrl(c, RES_H_IUS); +} + +/** + * z8530_status_clear - Handle status events from a stopped chip + * @chan: Z8530 channel to shut up + * + * Status 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_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); + +/** + * z8530_interrupt - Handle an interrupt from a Z8530 + * @irq: Interrupt number + * @dev_id: The Z8530 device that is interrupting. + * + * A Z85[2]30 device has stuck its hand in the air for attention. + * We scan both the channels on the chip for events and then call + * the channel specific call backs for each channel that has events. + * We have to use callback functions because the two channels can be + * in different modes. + * + * Locking is done for the handlers. Note that locking is done + * at the chip level (the 5uS delay issue is per chip not per + * channel). c->lock for both channels points to dev->lock + */ + +irqreturn_t z8530_interrupt(int irq, void *dev_id) +{ + struct z8530_dev *dev=dev_id; + u8 uninitialized_var(intr); + static volatile int locker=0; + int work=0; + struct z8530_irqhandler *irqs; + + if(locker) + { + pr_err("IRQ re-enter\n"); + return IRQ_NONE; + } + locker=1; + + spin_lock(&dev->lock); + + while(++work<5000) + { + + 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 */ + + irqs=dev->chanA.irqs; + + 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); + } + } + spin_unlock(&dev->lock); + if(work==5000) + pr_err("%s: interrupt jammed - abort(0x%X)!\n", + dev->name, intr); + /* Ok all done */ + locker=0; + return IRQ_HANDLED; +} + +EXPORT_SYMBOL(z8530_interrupt); + +static const u8 reg_init[16]= +{ + 0,0,0,0, + 0,0,0,0, + 0,0,0,0, + 0x55,0,0,0 +}; + + +/** + * z8530_sync_open - Open a Z8530 channel for PIO + * @dev: The network interface we are using + * @c: The Z8530 channel to open in synchronous PIO mode + * + * Switch a Z8530 into synchronous mode without DMA assist. We + * raise the RTS/DTR and commence network operation. + */ + +int z8530_sync_open(struct net_device *dev, struct z8530_channel *c) +{ + unsigned long flags; + + spin_lock_irqsave(c->lock, flags); + + c->sync = 1; + c->mtu = dev->mtu+64; + 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); + c->dma_tx = 0; + c->regs[R1]|=TxINT_ENAB; + write_zsreg(c, R1, c->regs[R1]); + write_zsreg(c, R3, c->regs[R3]|RxENABLE); + + spin_unlock_irqrestore(c->lock, flags); + return 0; +} + + +EXPORT_SYMBOL(z8530_sync_open); + +/** + * z8530_sync_close - Close a PIO Z8530 channel + * @dev: Network device to close + * @c: Z8530 channel to disassociate and move to idle + * + * Close down a Z8530 interface and switch its interrupt handlers + * to discard future events. + */ + +int z8530_sync_close(struct net_device *dev, struct z8530_channel *c) +{ + u8 chk; + unsigned long flags; + + spin_lock_irqsave(c->lock, flags); + 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); + + spin_unlock_irqrestore(c->lock, flags); + return 0; +} + +EXPORT_SYMBOL(z8530_sync_close); + +/** + * z8530_sync_dma_open - Open a Z8530 for DMA I/O + * @dev: The network device to attach + * @c: The Z8530 channel to configure in sync DMA mode. + * + * Set up a Z85x30 device for synchronous DMA in both directions. Two + * ISA DMA channels must be available for this to work. We assume ISA + * DMA driven I/O and PC limits on access. + */ + +int z8530_sync_dma_open(struct net_device *dev, struct z8530_channel *c) +{ + unsigned long cflags, dflags; + + c->sync = 1; + c->mtu = dev->mtu+64; + 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. Limit by page size. + * Everyone runs 1500 mtu or less on wan links so this + * should be fine. + */ + + if(c->mtu > PAGE_SIZE/2) + return -EMSGSIZE; + + c->rx_buf[0]=(void *)get_zeroed_page(GFP_KERNEL|GFP_DMA); + if(c->rx_buf[0]==NULL) + return -ENOBUFS; + c->rx_buf[1]=c->rx_buf[0]+PAGE_SIZE/2; + + c->tx_dma_buf[0]=(void *)get_zeroed_page(GFP_KERNEL|GFP_DMA); + if(c->tx_dma_buf[0]==NULL) + { + free_page((unsigned long)c->rx_buf[0]); + c->rx_buf[0]=NULL; + return -ENOBUFS; + } + c->tx_dma_buf[1]=c->tx_dma_buf[0]+PAGE_SIZE/2; + + c->tx_dma_used=0; + c->dma_tx = 1; + c->dma_num=0; + c->dma_ready=1; + + /* + * Enable DMA control mode + */ + + spin_lock_irqsave(c->lock, cflags); + + /* + * TX DMA via DIR/REQ + */ + + c->regs[R14]|= DTRREQ; + write_zsreg(c, R14, c->regs[R14]); + + c->regs[R1]&= ~TxINT_ENAB; + write_zsreg(c, R1, c->regs[R1]); + + /* + * RX DMA via W/Req + */ + + c->regs[R1]|= WT_FN_RDYFN; + c->regs[R1]|= WT_RDY_RT; + c->regs[R1]|= INT_ERR_Rx; + c->regs[R1]&= ~TxINT_ENAB; + write_zsreg(c, R1, c->regs[R1]); + c->regs[R1]|= WT_RDY_ENAB; + write_zsreg(c, R1, c->regs[R1]); + + /* + * DMA interrupts + */ + + /* + * Set up the DMA configuration + */ + + dflags=claim_dma_lock(); + + disable_dma(c->rxdma); + clear_dma_ff(c->rxdma); + set_dma_mode(c->rxdma, DMA_MODE_READ|0x10); + 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); + + release_dma_lock(dflags); + + /* + * 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); + + spin_unlock_irqrestore(c->lock, cflags); + + return 0; +} + +EXPORT_SYMBOL(z8530_sync_dma_open); + +/** + * z8530_sync_dma_close - Close down DMA I/O + * @dev: Network device to detach + * @c: Z8530 channel to move into discard mode + * + * Shut down a DMA mode synchronous interface. Halt the DMA, and + * free the buffers. + */ + +int z8530_sync_dma_close(struct net_device *dev, struct z8530_channel *c) +{ + u8 chk; + unsigned long flags; + + c->irqs = &z8530_nop; + c->max = 0; + c->sync = 0; + + /* + * Disable the PC DMA channels + */ + + flags=claim_dma_lock(); + disable_dma(c->rxdma); + clear_dma_ff(c->rxdma); + + c->rxdma_on = 0; + + disable_dma(c->txdma); + clear_dma_ff(c->txdma); + release_dma_lock(flags); + + c->txdma_on = 0; + c->tx_dma_used = 0; + + spin_lock_irqsave(c->lock, flags); + + /* + * 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]) + { + free_page((unsigned long)c->rx_buf[0]); + c->rx_buf[0]=NULL; + } + if(c->tx_dma_buf[0]) + { + free_page((unsigned long)c->tx_dma_buf[0]); + c->tx_dma_buf[0]=NULL; + } + chk=read_zsreg(c,R0); + write_zsreg(c, R3, c->regs[R3]); + z8530_rtsdtr(c,0); + + spin_unlock_irqrestore(c->lock, flags); + + return 0; +} + +EXPORT_SYMBOL(z8530_sync_dma_close); + +/** + * z8530_sync_txdma_open - Open a Z8530 for TX driven DMA + * @dev: The network device to attach + * @c: The Z8530 channel to configure in sync DMA mode. + * + * Set up a Z85x30 device for synchronous DMA tranmission. One + * ISA DMA channel must be available for this to work. The receive + * side is run in PIO mode, but then it has the bigger FIFO. + */ + +int z8530_sync_txdma_open(struct net_device *dev, struct z8530_channel *c) +{ + unsigned long cflags, dflags; + + printk("Opening sync interface for TX-DMA\n"); + c->sync = 1; + c->mtu = dev->mtu+64; + c->count = 0; + c->skb = NULL; + c->skb2 = NULL; + + /* + * Allocate the DMA flip buffers. Limit by page size. + * Everyone runs 1500 mtu or less on wan links so this + * should be fine. + */ + + if(c->mtu > PAGE_SIZE/2) + return -EMSGSIZE; + + c->tx_dma_buf[0]=(void *)get_zeroed_page(GFP_KERNEL|GFP_DMA); + if(c->tx_dma_buf[0]==NULL) + return -ENOBUFS; + + c->tx_dma_buf[1] = c->tx_dma_buf[0] + PAGE_SIZE/2; + + + spin_lock_irqsave(c->lock, cflags); + + /* + * Load the PIO receive ring + */ + + z8530_rx_done(c); + z8530_rx_done(c); + + /* + * Load the DMA interfaces up + */ + + c->rxdma_on = 0; + c->txdma_on = 0; + + c->tx_dma_used=0; + c->dma_num=0; + c->dma_ready=1; + c->dma_tx = 1; + + /* + * Enable DMA control mode + */ + + /* + * TX DMA via DIR/REQ + */ + c->regs[R14]|= DTRREQ; + write_zsreg(c, R14, c->regs[R14]); + + c->regs[R1]&= ~TxINT_ENAB; + write_zsreg(c, R1, c->regs[R1]); + + /* + * Set up the DMA configuration + */ + + dflags = claim_dma_lock(); + + disable_dma(c->txdma); + clear_dma_ff(c->txdma); + set_dma_mode(c->txdma, DMA_MODE_WRITE); + disable_dma(c->txdma); + + release_dma_lock(dflags); + + /* + * Select the DMA interrupt handlers + */ + + c->rxdma_on = 0; + c->txdma_on = 1; + c->tx_dma_used = 1; + + c->irqs = &z8530_txdma_sync; + z8530_rtsdtr(c,1); + write_zsreg(c, R3, c->regs[R3]|RxENABLE); + spin_unlock_irqrestore(c->lock, cflags); + + return 0; +} + +EXPORT_SYMBOL(z8530_sync_txdma_open); + +/** + * z8530_sync_txdma_close - Close down a TX driven DMA channel + * @dev: Network device to detach + * @c: Z8530 channel to move into discard mode + * + * Shut down a DMA/PIO split mode synchronous interface. Halt the DMA, + * and free the buffers. + */ + +int z8530_sync_txdma_close(struct net_device *dev, struct z8530_channel *c) +{ + unsigned long dflags, cflags; + u8 chk; + + + spin_lock_irqsave(c->lock, cflags); + + c->irqs = &z8530_nop; + c->max = 0; + c->sync = 0; + + /* + * Disable the PC DMA channels + */ + + dflags = claim_dma_lock(); + + disable_dma(c->txdma); + clear_dma_ff(c->txdma); + c->txdma_on = 0; + c->tx_dma_used = 0; + + release_dma_lock(dflags); + + /* + * 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->tx_dma_buf[0]) + { + free_page((unsigned long)c->tx_dma_buf[0]); + c->tx_dma_buf[0]=NULL; + } + chk=read_zsreg(c,R0); + write_zsreg(c, R3, c->regs[R3]); + z8530_rtsdtr(c,0); + + spin_unlock_irqrestore(c->lock, cflags); + return 0; +} + + +EXPORT_SYMBOL(z8530_sync_txdma_close); + + +/* + * Name strings for Z8530 chips. SGI claim to have a 130, Zilog deny + * it exists... + */ + +static const char *z8530_type_name[]={ + "Z8530", + "Z85C30", + "Z85230" +}; + +/** + * z8530_describe - Uniformly describe a Z8530 port + * @dev: Z8530 device to describe + * @mapping: string holding mapping type (eg "I/O" or "Mem") + * @io: the port value in question + * + * Describe a Z8530 in a standard format. We must pass the I/O as + * the port offset isn't predictable. The main reason for this function + * is to try and get a common format of report. + */ + +void z8530_describe(struct z8530_dev *dev, char *mapping, unsigned long io) +{ + pr_info("%s: %s found at %s 0x%lX, IRQ %d\n", + dev->name, + z8530_type_name[dev->type], + mapping, + Z8530_PORT_OF(io), + dev->irq); +} + +EXPORT_SYMBOL(z8530_describe); + +/* + * Locked operation part of the z8530 init code + */ + +static inline int do_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; + dev->chanA.dcdcheck=DCD; + dev->chanB.dcdcheck=DCD; + + /* Reset the chip */ + write_zsreg(&dev->chanA, R9, 0xC0); + udelay(200); + /* 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; +} + +/** + * z8530_init - Initialise a Z8530 device + * @dev: Z8530 device to initialise. + * + * Configure up a Z8530/Z85C30 or Z85230 chip. We check the device + * is present, identify the type and then program it to hopefully + * keep quite and behave. This matters a lot, a Z8530 in the wrong + * state will sometimes get into stupid modes generating 10Khz + * interrupt streams and the like. + * + * We set the interrupt handler up to discard any events, in case + * we get them during reset or setp. + * + * Return 0 for success, or a negative value indicating the problem + * in errno form. + */ + +int z8530_init(struct z8530_dev *dev) +{ + unsigned long flags; + int ret; + + /* Set up the chip level lock */ + spin_lock_init(&dev->lock); + dev->chanA.lock = &dev->lock; + dev->chanB.lock = &dev->lock; + + spin_lock_irqsave(&dev->lock, flags); + ret = do_z8530_init(dev); + spin_unlock_irqrestore(&dev->lock, flags); + + return ret; +} + + +EXPORT_SYMBOL(z8530_init); + +/** + * z8530_shutdown - Shutdown a Z8530 device + * @dev: The Z8530 chip to shutdown + * + * We set the interrupt handlers to silence any interrupts. We then + * reset the chip and wait 100uS to be sure the reset completed. Just + * in case the caller then tries to do stuff. + * + * This is called without the lock held + */ + +int z8530_shutdown(struct z8530_dev *dev) +{ + unsigned long flags; + /* Reset the chip */ + + spin_lock_irqsave(&dev->lock, flags); + dev->chanA.irqs=&z8530_nop; + dev->chanB.irqs=&z8530_nop; + write_zsreg(&dev->chanA, R9, 0xC0); + /* We must lock the udelay, the chip is offlimits here */ + udelay(100); + spin_unlock_irqrestore(&dev->lock, flags); + return 0; +} + +EXPORT_SYMBOL(z8530_shutdown); + +/** + * z8530_channel_load - Load channel data + * @c: Z8530 channel to configure + * @rtable: table of register, value pairs + * FIXME: ioctl to allow user uploaded tables + * + * Load a Z8530 channel up from the system data. We use +16 to + * indicate the "prime" registers. The value 255 terminates the + * table. + */ + +int z8530_channel_load(struct z8530_channel *c, u8 *rtable) +{ + unsigned long flags; + + spin_lock_irqsave(c->lock, flags); + + 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=read_zsreg(c, R0); + c->sync=1; + write_zsreg(c, R3, c->regs[R3]|RxENABLE); + + spin_unlock_irqrestore(c->lock, flags); + return 0; +} + +EXPORT_SYMBOL(z8530_channel_load); + + +/** + * z8530_tx_begin - Begin packet transmission + * @c: The Z8530 channel to kick + * + * This is the speed sensitive side of transmission. If we are called + * and no buffer is being transmitted we commence the next buffer. If + * nothing is queued we idle the sync. + * + * Note: We are handling this code path in the interrupt path, keep it + * fast or bad things will happen. + * + * Called with the lock held. + */ + +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; + + if(c->tx_skb==NULL) + { + /* Idle on */ + if(c->dma_tx) + { + flags=claim_dma_lock(); + disable_dma(c->txdma); + /* + * Check if we crapped out. + */ + if (get_dma_residue(c->txdma)) + { + c->netdevice->stats.tx_dropped++; + c->netdevice->stats.tx_fifo_errors++; + } + release_dma_lock(flags); + } + c->txcount=0; + } + else + { + c->txcount=c->tx_skb->len; + + + if(c->dma_tx) + { + /* + * FIXME. DMA is broken for the original 8530, + * on the older parts we need to set a flag and + * wait for a further TX interrupt to fire this + * stage off + */ + + flags=claim_dma_lock(); + disable_dma(c->txdma); + + /* + * These two are needed by the 8530/85C30 + * and must be issued when idling. + */ + + if(c->dev->type!=Z85230) + { + write_zsctrl(c, RES_Tx_CRC); + write_zsctrl(c, RES_EOM_L); + } + write_zsreg(c, R10, c->regs[10]&~ABUNDER); + 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); + release_dma_lock(flags); + write_zsctrl(c, RES_EOM_L); + write_zsreg(c, R5, c->regs[R5]|TxENAB); + } + else + { + + /* ABUNDER off */ + write_zsreg(c, R10, c->regs[10]); + write_zsctrl(c, RES_Tx_CRC); + + while(c->txcount && (read_zsreg(c,R0)&Tx_BUF_EMP)) + { + write_zsreg(c, R8, *c->tx_ptr++); + c->txcount--; + } + + } + } + /* + * Since we emptied tx_skb we can ask for more + */ + netif_wake_queue(c->netdevice); +} + +/** + * z8530_tx_done - TX complete callback + * @c: The channel that completed a transmit. + * + * This is called when we complete a packet send. We wake the queue, + * start the next packet going and then free the buffer of the existing + * packet. This code is fairly timing sensitive. + * + * Called with the register lock held. + */ + +static void z8530_tx_done(struct z8530_channel *c) +{ + struct sk_buff *skb; + + /* Actually this can happen.*/ + if (c->tx_skb == NULL) + return; + + skb = c->tx_skb; + c->tx_skb = NULL; + z8530_tx_begin(c); + c->netdevice->stats.tx_packets++; + c->netdevice->stats.tx_bytes += skb->len; + dev_kfree_skb_irq(skb); +} + +/** + * z8530_null_rx - Discard a packet + * @c: The channel the packet arrived on + * @skb: The buffer + * + * We point the receive handler at this function when idle. Instead + * of processing the frames we get to throw them away. + */ + +void z8530_null_rx(struct z8530_channel *c, struct sk_buff *skb) +{ + dev_kfree_skb_any(skb); +} + +EXPORT_SYMBOL(z8530_null_rx); + +/** + * z8530_rx_done - Receive completion callback + * @c: The channel that completed a receive + * + * A new packet is complete. Our goal here is to get back into receive + * mode as fast as possible. On the Z85230 we could change to using + * ESCC mode, but on the older chips we have no choice. We flip to the + * new buffer immediately in DMA mode so that the DMA of the next + * frame can occur while we are copying the previous buffer to an sk_buff + * + * Called with the lock held + */ + +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; + unsigned char *rxb=c->rx_buf[c->dma_num]; + unsigned long flags; + + /* + * Complete this DMA. Necessary to find the length + */ + + flags=claim_dma_lock(); + + disable_dma(c->rxdma); + clear_dma_ff(c->rxdma); + c->rxdma_on=0; + ct=c->mtu-get_dma_residue(c->rxdma); + 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|0x10); + 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); + /* Stop any frames that we missed the head of + from passing */ + write_zsreg(c, R0, RES_Rx_CRC); + } + else + /* Can't occur as we dont reenable the DMA irq until + after the flip is done */ + netdev_warn(c->netdevice, "DMA flip overrun!\n"); + + release_dma_lock(flags); + + /* + * 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) { + c->netdevice->stats.rx_dropped++; + netdev_warn(c->netdevice, "Memory squeeze\n"); + } else { + skb_put(skb, ct); + skb_copy_to_linear_data(skb, rxb, ct); + c->netdevice->stats.rx_packets++; + c->netdevice->stats.rx_bytes += ct; + } + 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 isn't 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) + netdev_warn(c->netdevice, "memory squeeze\n"); + else + skb_put(c->skb2, c->mtu); + c->netdevice->stats.rx_packets++; + c->netdevice->stats.rx_bytes += ct; + } + /* + * If we received a frame we must now process it. + */ + if (skb) { + skb_trim(skb, ct); + c->rx_function(c, skb); + } else { + c->netdevice->stats.rx_dropped++; + netdev_err(c->netdevice, "Lost a frame\n"); + } +} + +/** + * spans_boundary - Check a packet can be ISA DMA'd + * @skb: The buffer to check + * + * Returns true if the buffer cross a DMA boundary on a PC. The poor + * thing can only DMA within a 64K block not across the edges of it. + */ + +static inline int spans_boundary(struct sk_buff *skb) +{ + unsigned long a=(unsigned long)skb->data; + a^=(a+skb->len); + if(a&0x00010000) /* If the 64K bit is different.. */ + return 1; + return 0; +} + +/** + * z8530_queue_xmit - Queue a packet + * @c: The channel to use + * @skb: The packet to kick down the channel + * + * 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. + * + * Called from the network code. The lock is not held at this + * point. + */ + +netdev_tx_t z8530_queue_xmit(struct z8530_channel *c, struct sk_buff *skb) +{ + unsigned long flags; + + netif_stop_queue(c->netdevice); + if(c->tx_next_skb) + return NETDEV_TX_BUSY; + + + /* 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 || spans_boundary(skb))) + { + /* + * 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 */ + skb_copy_from_linear_data(skb, c->tx_next_ptr, skb->len); + } + else + c->tx_next_ptr=skb->data; + RT_LOCK; + c->tx_next_skb=skb; + RT_UNLOCK; + + spin_lock_irqsave(c->lock, flags); + z8530_tx_begin(c); + spin_unlock_irqrestore(c->lock, flags); + + return NETDEV_TX_OK; +} + +EXPORT_SYMBOL(z8530_queue_xmit); + +/* + * Module support + */ +static const char banner[] __initconst = + KERN_INFO "Generic Z85C30/Z85230 interface driver v0.02\n"; + +static int __init z85230_init_driver(void) +{ + printk(banner); + return 0; +} +module_init(z85230_init_driver); + +static void __exit z85230_cleanup_driver(void) +{ +} +module_exit(z85230_cleanup_driver); + +MODULE_AUTHOR("Red Hat Inc."); +MODULE_DESCRIPTION("Z85x30 synchronous driver core"); +MODULE_LICENSE("GPL"); |