cosa.c

优龙2410linux2.6.8内核源代码

	 * The following loop is indexed through i (instead of id)
	 * to avoid looping forever when for any reason
	 * the port returns '\r', '\n' or '\x2e' permanently.
	 */
	for (i=0; i<COSA_MAX_ID_STRING-1; i++, prev=curr) {
		if ((curr = get_wait_data(cosa)) == -1) {
			return -1;
		}
		curr &= 0xff;
		if (curr != '\r' && curr != '\n' && curr != 0x2e)
			idstring[id++] = curr;
		if (curr == 0x2e && prev == '\n')
			break;
	}
	/* Perhaps we should fail when i==COSA_MAX_ID_STRING-1 ? */
	idstring[id] = '\0';
	return id;
}


/* ---------- Auxiliary routines for COSA/SRP monitor ---------- */

/*
 * This routine gets the data byte from the card waiting for the SR_RX_RDY
 * bit to be set in a loop. It should be used in the exceptional cases
 * only (for example when resetting the card or downloading the firmware.
 */
static int get_wait_data(struct cosa_data *cosa)
{
	int retries = 1000;

	while (--retries) {
		/* read data and return them */
		if (cosa_getstatus(cosa) & SR_RX_RDY) {
			short r;
			r = cosa_getdata8(cosa);
#if 0
			printk(KERN_INFO "cosa: get_wait_data returning after %d retries\n", 999-retries);
#endif
			return r;
		}
		/* sleep if not ready to read */
		current->state = TASK_INTERRUPTIBLE;
		schedule_timeout(1);
	}
	printk(KERN_INFO "cosa: timeout in get_wait_data (status 0x%x)\n",
		cosa_getstatus(cosa));
	return -1;
}

/*
 * This routine puts the data byte to the card waiting for the SR_TX_RDY
 * bit to be set in a loop. It should be used in the exceptional cases
 * only (for example when resetting the card or downloading the firmware).
 */
static int put_wait_data(struct cosa_data *cosa, int data)
{
	int retries = 1000;
	while (--retries) {
		/* read data and return them */
		if (cosa_getstatus(cosa) & SR_TX_RDY) {
			cosa_putdata8(cosa, data);
#if 0
			printk(KERN_INFO "Putdata: %d retries\n", 999-retries);
#endif
			return 0;
		}
#if 0
		/* sleep if not ready to read */
		current->state = TASK_INTERRUPTIBLE;
		schedule_timeout(1);
#endif
	}
	printk(KERN_INFO "cosa%d: timeout in put_wait_data (status 0x%x)\n",
		cosa->num, cosa_getstatus(cosa));
	return -1;
}
	
/* 
 * The following routine puts the hexadecimal number into the SRP monitor
 * and verifies the proper echo of the sent bytes. Returns 0 on success,
 * negative number on failure (-1,-3,-5,-7) means that put_wait_data() failed,
 * (-2,-4,-6,-8) means that reading echo failed.
 */
static int puthexnumber(struct cosa_data *cosa, int number)
{
	char temp[5];
	int i;

	/* Well, I should probably replace this by something faster. */
	sprintf(temp, "%04X", number);
	for (i=0; i<4; i++) {
		if (put_wait_data(cosa, temp[i]) == -1) {
			printk(KERN_NOTICE "cosa%d: puthexnumber failed to write byte %d\n",
				cosa->num, i);
			return -1-2*i;
		}
		if (get_wait_data(cosa) != temp[i]) {
			printk(KERN_NOTICE "cosa%d: puthexhumber failed to read echo of byte %d\n",
				cosa->num, i);
			return -2-2*i;
		}
	}
	return 0;
}


/* ---------- Interrupt routines ---------- */

/*
 * There are three types of interrupt:
 * At the beginning of transmit - this handled is in tx_interrupt(),
 * at the beginning of receive - it is in rx_interrupt() and
 * at the end of transmit/receive - it is the eot_interrupt() function.
 * These functions are multiplexed by cosa_interrupt() according to the
 * COSA status byte. I have moved the rx/tx/eot interrupt handling into
 * separate functions to make it more readable. These functions are inline,
 * so there should be no overhead of function call.
 * 
 * In the COSA bus-master mode, we need to tell the card the address of a
 * buffer. Unfortunately, COSA may be too slow for us, so we must busy-wait.
 * It's time to use the bottom half :-(
 */

/*
 * Transmit interrupt routine - called when COSA is willing to obtain
 * data from the OS. The most tricky part of the routine is selection
 * of channel we (OS) want to send packet for. For SRP we should probably
 * use the round-robin approach. The newer COSA firmwares have a simple
 * flow-control - in the status word has bits 2 and 3 set to 1 means that the
 * channel 0 or 1 doesn't want to receive data.
 *
 * It seems there is a bug in COSA firmware (need to trace it further):
 * When the driver status says that the kernel has no more data for transmit
 * (e.g. at the end of TX DMA) and then the kernel changes its mind
 * (e.g. new packet is queued to hard_start_xmit()), the card issues
 * the TX interrupt but does not mark the channel as ready-to-transmit.
 * The fix seems to be to push the packet to COSA despite its request.
 * We first try to obey the card's opinion, and then fall back to forced TX.
 */
static inline void tx_interrupt(struct cosa_data *cosa, int status)
{
	unsigned long flags, flags1;
#ifdef DEBUG_IRQS
	printk(KERN_INFO "cosa%d: SR_DOWN_REQUEST status=0x%04x\n",
		cosa->num, status);
#endif
	spin_lock_irqsave(&cosa->lock, flags);
	set_bit(TXBIT, &cosa->rxtx);
	if (!test_bit(IRQBIT, &cosa->rxtx)) {
		/* flow control, see the comment above */
		int i=0;
		if (!cosa->txbitmap) {
			printk(KERN_WARNING "%s: No channel wants data "
				"in TX IRQ. Expect DMA timeout.",
				cosa->name);
			put_driver_status_nolock(cosa);
			clear_bit(TXBIT, &cosa->rxtx);
			spin_unlock_irqrestore(&cosa->lock, flags);
			return;
		}
		while(1) {
			cosa->txchan++;
			i++;
			if (cosa->txchan >= cosa->nchannels)
				cosa->txchan = 0;
			if (!(cosa->txbitmap & (1<<cosa->txchan)))
				continue;
			if (~status & (1 << (cosa->txchan+DRIVER_TXMAP_SHIFT)))
				break;
			/* in second pass, accept first ready-to-TX channel */
			if (i > cosa->nchannels) {
				/* Can be safely ignored */
#ifdef DEBUG_IRQS
				printk(KERN_DEBUG "%s: Forcing TX "
					"to not-ready channel %d\n",
					cosa->name, cosa->txchan);
#endif
				break;
			}
		}

		cosa->txsize = cosa->chan[cosa->txchan].txsize;
		if (cosa_dma_able(cosa->chan+cosa->txchan,
			cosa->chan[cosa->txchan].txbuf, cosa->txsize)) {
			cosa->txbuf = cosa->chan[cosa->txchan].txbuf;
		} else {
			memcpy(cosa->bouncebuf, cosa->chan[cosa->txchan].txbuf,
				cosa->txsize);
			cosa->txbuf = cosa->bouncebuf;
		}
	}

	if (is_8bit(cosa)) {
		if (!test_bit(IRQBIT, &cosa->rxtx)) {
			cosa_putstatus(cosa, SR_TX_INT_ENA);
			cosa_putdata8(cosa, ((cosa->txchan << 5) & 0xe0)|
				((cosa->txsize >> 8) & 0x1f));
#ifdef DEBUG_IO
			debug_status_out(cosa, SR_TX_INT_ENA);
			debug_data_out(cosa, ((cosa->txchan << 5) & 0xe0)|
                                ((cosa->txsize >> 8) & 0x1f));
			debug_data_in(cosa, cosa_getdata8(cosa));
#else
			cosa_getdata8(cosa);
#endif
			set_bit(IRQBIT, &cosa->rxtx);
			spin_unlock_irqrestore(&cosa->lock, flags);
			return;
		} else {
			clear_bit(IRQBIT, &cosa->rxtx);
			cosa_putstatus(cosa, 0);
			cosa_putdata8(cosa, cosa->txsize&0xff);
#ifdef DEBUG_IO
			debug_status_out(cosa, 0);
			debug_data_out(cosa, cosa->txsize&0xff);
#endif
		}
	} else {
		cosa_putstatus(cosa, SR_TX_INT_ENA);
		cosa_putdata16(cosa, ((cosa->txchan<<13) & 0xe000)
			| (cosa->txsize & 0x1fff));
#ifdef DEBUG_IO
		debug_status_out(cosa, SR_TX_INT_ENA);
		debug_data_out(cosa, ((cosa->txchan<<13) & 0xe000)
                        | (cosa->txsize & 0x1fff));
		debug_data_in(cosa, cosa_getdata8(cosa));
		debug_status_out(cosa, 0);
#else
		cosa_getdata8(cosa);
#endif
		cosa_putstatus(cosa, 0);
	}

	if (cosa->busmaster) {
		unsigned long addr = virt_to_bus(cosa->txbuf);
		int count=0;
		printk(KERN_INFO "busmaster IRQ\n");
		while (!(cosa_getstatus(cosa)&SR_TX_RDY)) {
			count++;
			udelay(10);
			if (count > 1000) break;
		}
		printk(KERN_INFO "status %x\n", cosa_getstatus(cosa));
		printk(KERN_INFO "ready after %d loops\n", count);
		cosa_putdata16(cosa, (addr >> 16)&0xffff);

		count = 0;
		while (!(cosa_getstatus(cosa)&SR_TX_RDY)) {
			count++;
			if (count > 1000) break;
			udelay(10);
		}
		printk(KERN_INFO "ready after %d loops\n", count);
		cosa_putdata16(cosa, addr &0xffff);
		flags1 = claim_dma_lock();
		set_dma_mode(cosa->dma, DMA_MODE_CASCADE);
		enable_dma(cosa->dma);
		release_dma_lock(flags1);
	} else {
		/* start the DMA */
		flags1 = claim_dma_lock();
		disable_dma(cosa->dma);
		clear_dma_ff(cosa->dma);
		set_dma_mode(cosa->dma, DMA_MODE_WRITE);
		set_dma_addr(cosa->dma, virt_to_bus(cosa->txbuf));
		set_dma_count(cosa->dma, cosa->txsize);
		enable_dma(cosa->dma);
		release_dma_lock(flags1);
	}
	cosa_putstatus(cosa, SR_TX_DMA_ENA|SR_USR_INT_ENA);
#ifdef DEBUG_IO
	debug_status_out(cosa, SR_TX_DMA_ENA|SR_USR_INT_ENA);
#endif
	spin_unlock_irqrestore(&cosa->lock, flags);
}

static inline void rx_interrupt(struct cosa_data *cosa, int status)
{
	unsigned long flags;
#ifdef DEBUG_IRQS
	printk(KERN_INFO "cosa%d: SR_UP_REQUEST\n", cosa->num);
#endif

	spin_lock_irqsave(&cosa->lock, flags);
	set_bit(RXBIT, &cosa->rxtx);

	if (is_8bit(cosa)) {
		if (!test_bit(IRQBIT, &cosa->rxtx)) {
			set_bit(IRQBIT, &cosa->rxtx);
			put_driver_status_nolock(cosa);
			cosa->rxsize = cosa_getdata8(cosa) <<8;
#ifdef DEBUG_IO
			debug_data_in(cosa, cosa->rxsize >> 8);
#endif
			spin_unlock_irqrestore(&cosa->lock, flags);
			return;
		} else {
			clear_bit(IRQBIT, &cosa->rxtx);
			cosa->rxsize |= cosa_getdata8(cosa) & 0xff;
#ifdef DEBUG_IO
			debug_data_in(cosa, cosa->rxsize & 0xff);
#endif
#if 0
			printk(KERN_INFO "cosa%d: receive rxsize = (0x%04x).\n",
				cosa->num, cosa->rxsize);
#endif
		}
	} else {
		cosa->rxsize = cosa_getdata16(cosa);
#ifdef DEBUG_IO
		debug_data_in(cosa, cosa->rxsize);
#endif
#if 0
		printk(KERN_INFO "cosa%d: receive rxsize = (0x%04x).\n",
			cosa->num, cosa->rxsize);
#endif
	}
	if (((cosa->rxsize & 0xe000) >> 13) >= cosa->nchannels) {
		printk(KERN_WARNING "%s: rx for unknown channel (0x%04x)\n",
			cosa->name, cosa->rxsize);
		spin_unlock_irqrestore(&cosa->lock, flags);
		goto reject;
	}
	cosa->rxchan = cosa->chan + ((cosa->rxsize & 0xe000) >> 13);
	cosa->rxsize &= 0x1fff;
	spin_unlock_irqrestore(&cosa->lock, flags);

	cosa->rxbuf = NULL;
	if (cosa->rxchan->setup_rx)
		cosa->rxbuf = cosa->rxchan->setup_rx(cosa->rxchan, cosa->rxsize);

	if (!cosa->rxbuf) {
reject:		/* Reject the packet */
		printk(KERN_INFO "cosa%d: rejecting packet on channel %d\n",
			cosa->num, cosa->rxchan->num);
		cosa->rxbuf = cosa->bouncebuf;
	}

	/* start the DMA */
	flags = claim_dma_lock();
	disable_dma(cosa->dma);
	clear_dma_ff(cosa->dma);
	set_dma_mode(cosa->dma, DMA_MODE_READ);
	if (cosa_dma_able(cosa->rxchan, cosa->rxbuf, cosa->rxsize & 0x1fff)) {
		set_dma_addr(cosa->dma, virt_to_bus(cosa->rxbuf));
	} else {
		set_dma_addr(cosa->dma, virt_to_bus(cosa->bouncebuf));
	}
	set_dma_count(cosa->dma, (cosa->rxsize&0x1fff));
	enable_dma(cosa->dma);
	release_dma_lock(flags);
	spin_lock_irqsave(&cosa->lock, flags);
	cosa_putstatus(cosa, SR_RX_DMA_ENA|SR_USR_INT_ENA);
	if (!is_8bit(cosa) && (status & SR_TX_RDY))
		cosa_putdata8(cosa, DRIVER_RX_READY);
#ifdef DEBUG_IO
	debug_status_out(cosa, SR_RX_DMA_ENA|SR_USR_INT_ENA);
	if (!is_8bit(cosa) && (status & SR_TX_RDY))
		debug_data_cmd(cosa, DRIVER_RX_READY);
#endif
	spin_unlock_irqrestore(&cosa->lock, flags);
}

static inline void eot_interrupt(struct cosa_data *cosa, int status)
{
	unsigned long flags, flags1;
	spin_lock_irqsave(&cosa->lock, flags);
	flags1 = claim_dma_lock();
	disable_dma(cosa->dma);
	clear_dma_ff(cosa->dma);
	release_dma_lock(flags1);
	if (test_bit(TXBIT, &cosa->rxtx)) {
		struct channel_data *chan = cosa->chan+cosa->txchan;
		if (chan->tx_done)
			if (chan->tx_done(chan, cosa->txsize))
				clear_bit(chan->num, &cosa->txbitmap);
	} else if (test_bit(RXBIT, &cosa->rxtx)) {
#ifdef DEBUG_DATA
	{
		int i;
		printk(KERN_INFO "cosa%dc%d: done rx(0x%x)", cosa->num, 
			cosa->rxchan->num, cosa->rxsize);
		for (i=0; i<cosa->rxsize; i++)
			printk (" %02x", cosa->rxbuf[i]&0xff);
		printk("\n");
	}
#endif
		/* Packet for unknown channel? */
		if (cosa->rxbuf == cosa->bouncebuf)
			goto out;
		if (!cosa_dma_able(cosa->rxchan, cosa->rxbuf, cosa->rxsize))
			memcpy(cosa->rxbuf, cosa->bouncebuf, cosa->rxsize);
		if (cosa->rxchan->rx_done)
			if (cosa->rxchan->rx_done(cosa->rxchan))
				clear_bit(cosa->rxchan->num, &cosa->rxbitmap);
	} else {
		printk(KERN_NOTICE "cosa%d: unexpected EOT interrupt\n",
			cosa->num);
	}
	/*
	 * Clear the RXBIT, TXBIT and IRQBIT (the latest should be
	 * cleared anyway). We should do it as soon as possible
	 * so that we can tell the COSA we are done and to give it a time
	 * for recovery.
	 */
out:
	cosa->rxtx = 0;
	put_driver_status_nolock(cosa);
	spin_unlock_irqrestore(&cosa->lock, flags);
}

static irqreturn_t cosa_interrupt(int irq, void *cosa_, struct pt_regs *regs)
{
	unsigned status;
	int count = 0;
	struct cosa_data *cosa = cosa_;
again:
	status = cosa_getstatus(cosa);
#ifdef DEBUG_IRQS
	printk(KERN_INFO "cosa%d: got IRQ, status 0x%02x\n", cosa->num,
		status & 0xff);
#endif
#ifdef DEBUG_IO
	debug_status_in(cosa, status);
#endif
	switch (status & SR_CMD_FROM_SRP_MASK) {
	case SR_DOWN_REQUEST:
		tx_interrupt(cosa, status);
		break;
	case SR_UP_REQUEST:
		rx_interrupt(cosa, status);
		break;
	case SR_END_OF_TRANSFER:
		eot_interrupt(cosa, status);
		break;
	default:
		/* We may be too fast for SRP. Try to wait a bit more. */
		if (count++ < 100) {
			udelay(100);
			goto again;
		}
		printk(KERN_INFO "cosa%d: unknown status 0x%02x in IRQ after %d retries\n",
			cosa->num, status & 0xff, count);
	}
#ifdef DEBUG_IRQS
	if (count)
		printk(KERN_INFO "%s: %d-times got unknown status in IRQ\n",
			cosa->name, count);
	else
		printk(KERN_INFO "%s: returning from IRQ\n", cosa->name);
#endif
	return IRQ_HANDLED;
}


/* ---------- I/O debugging routines ---------- */
/*
 * These routines can be used to monitor COSA/SRP I/O and to printk()
 * the data being transferred on the data and status I/O port in a
 * readable way.
 */

#ifdef DEBUG_IO
static void debug_status_in(struct cosa_data *cosa, int status)
{
	char *s;
	switch(status & SR_CMD_FROM_SRP_MASK) {
	case SR_UP_REQUEST:
		s = "RX_REQ";
		break;
	case SR_DOWN_REQUEST:
		s = "TX_REQ";
		break;
	case SR_END_OF_TRANSFER:
		s = "ET_REQ";
		break;
	default:
		s = "NO_REQ";
		break;
	}
	printk(KERN_INFO "%s: IO: status -> 0x%02x (%s%s%s%s)\n",
		cosa->name,
		status,
		status & SR_USR_RQ ? "USR_RQ|":"",
		status & SR_TX_RDY ? "TX_RDY|":"",
		status & SR_RX_RDY ? "RX_RDY|":"",
		s);
}

static void debug_status_out(struct cosa_data *cosa, int status)
{
	printk(KERN_INFO "%s: IO: status <- 0x%02x (%s%s%s%s%s%s)\n",
		cosa->name,
		status,
		status & SR_RX_DMA_ENA  ? "RXDMA|":"!rxdma|",
		status & SR_TX_DMA_ENA  ? "TXDMA|":"!txdma|",
		status & SR_RST         ? "RESET|":"",
		status & SR_USR_INT_ENA ? "USRINT|":"!usrint|",
		status & SR_TX_INT_ENA  ? "TXINT|":"!txint|",
		status & SR_RX_INT_ENA  ? "RXINT":"!rxint");
}

static void debug_data_in(struct cosa_data *cosa, int data)
{
	printk(KERN_INFO "%s: IO: data -> 0x%04x\n", cosa->name, data);
}

static void debug_data_out(struct cosa_data *cosa, int data)
{
	printk(KERN_INFO "%s: IO: data <- 0x%04x\n", cosa->name, data);
}

static void debug_data_cmd(struct cosa_data *cosa, int data)
{
	printk(KERN_INFO "%s: IO: data <- 0x%04x (%s|%s)\n",
		cosa->name, data,
		data & SR_RDY_RCV ? "RX_RDY" : "!rx_rdy",
		data & SR_RDY_SND ? "TX_RDY" : "!tx_rdy");
}
#endif

/* EOF -- this file has not been truncated */