1 /*
2  *	Driver for the Macintosh 68K onboard MACE controller with PSC
3  *	driven DMA. The MACE driver code is derived from mace.c. The
4  *	Mac68k theory of operation is courtesy of the MacBSD wizards.
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License
8  *	as published by the Free Software Foundation; either version
9  *	2 of the License, or (at your option) any later version.
10  *
11  *	Copyright (C) 1996 Paul Mackerras.
12  *	Copyright (C) 1998 Alan Cox <alan@lxorguk.ukuu.org.uk>
13  *
14  *	Modified heavily by Joshua M. Thompson based on Dave Huang's NetBSD driver
15  *
16  *	Copyright (C) 2007 Finn Thain
17  *
18  *	Converted to DMA API, converted to unified driver model,
19  *	sync'd some routines with mace.c and fixed various bugs.
20  */
21 
22 
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/netdevice.h>
26 #include <linux/etherdevice.h>
27 #include <linux/delay.h>
28 #include <linux/string.h>
29 #include <linux/crc32.h>
30 #include <linux/bitrev.h>
31 #include <linux/dma-mapping.h>
32 #include <linux/platform_device.h>
33 #include <linux/gfp.h>
34 #include <linux/interrupt.h>
35 #include <asm/io.h>
36 #include <asm/macints.h>
37 #include <asm/mac_psc.h>
38 #include <asm/page.h>
39 #include "mace.h"
40 
41 static char mac_mace_string[] = "macmace";
42 
43 #define N_TX_BUFF_ORDER	0
44 #define N_TX_RING	(1 << N_TX_BUFF_ORDER)
45 #define N_RX_BUFF_ORDER	3
46 #define N_RX_RING	(1 << N_RX_BUFF_ORDER)
47 
48 #define TX_TIMEOUT	HZ
49 
50 #define MACE_BUFF_SIZE	0x800
51 
52 /* Chip rev needs workaround on HW & multicast addr change */
53 #define BROKEN_ADDRCHG_REV	0x0941
54 
55 /* The MACE is simply wired down on a Mac68K box */
56 
57 #define MACE_BASE	(void *)(0x50F1C000)
58 #define MACE_PROM	(void *)(0x50F08001)
59 
60 struct mace_data {
61 	volatile struct mace *mace;
62 	unsigned char *tx_ring;
63 	dma_addr_t tx_ring_phys;
64 	unsigned char *rx_ring;
65 	dma_addr_t rx_ring_phys;
66 	int dma_intr;
67 	int rx_slot, rx_tail;
68 	int tx_slot, tx_sloti, tx_count;
69 	int chipid;
70 	struct device *device;
71 };
72 
73 struct mace_frame {
74 	u8	rcvcnt;
75 	u8	pad1;
76 	u8	rcvsts;
77 	u8	pad2;
78 	u8	rntpc;
79 	u8	pad3;
80 	u8	rcvcc;
81 	u8	pad4;
82 	u32	pad5;
83 	u32	pad6;
84 	u8	data[1];
85 	/* And frame continues.. */
86 };
87 
88 #define PRIV_BYTES	sizeof(struct mace_data)
89 
90 static int mace_open(struct net_device *dev);
91 static int mace_close(struct net_device *dev);
92 static int mace_xmit_start(struct sk_buff *skb, struct net_device *dev);
93 static void mace_set_multicast(struct net_device *dev);
94 static int mace_set_address(struct net_device *dev, void *addr);
95 static void mace_reset(struct net_device *dev);
96 static irqreturn_t mace_interrupt(int irq, void *dev_id);
97 static irqreturn_t mace_dma_intr(int irq, void *dev_id);
98 static void mace_tx_timeout(struct net_device *dev);
99 static void __mace_set_address(struct net_device *dev, void *addr);
100 
101 /*
102  * Load a receive DMA channel with a base address and ring length
103  */
104 
105 static void mace_load_rxdma_base(struct net_device *dev, int set)
106 {
107 	struct mace_data *mp = netdev_priv(dev);
108 
109 	psc_write_word(PSC_ENETRD_CMD + set, 0x0100);
110 	psc_write_long(PSC_ENETRD_ADDR + set, (u32) mp->rx_ring_phys);
111 	psc_write_long(PSC_ENETRD_LEN + set, N_RX_RING);
112 	psc_write_word(PSC_ENETRD_CMD + set, 0x9800);
113 	mp->rx_tail = 0;
114 }
115 
116 /*
117  * Reset the receive DMA subsystem
118  */
119 
120 static void mace_rxdma_reset(struct net_device *dev)
121 {
122 	struct mace_data *mp = netdev_priv(dev);
123 	volatile struct mace *mace = mp->mace;
124 	u8 maccc = mace->maccc;
125 
126 	mace->maccc = maccc & ~ENRCV;
127 
128 	psc_write_word(PSC_ENETRD_CTL, 0x8800);
129 	mace_load_rxdma_base(dev, 0x00);
130 	psc_write_word(PSC_ENETRD_CTL, 0x0400);
131 
132 	psc_write_word(PSC_ENETRD_CTL, 0x8800);
133 	mace_load_rxdma_base(dev, 0x10);
134 	psc_write_word(PSC_ENETRD_CTL, 0x0400);
135 
136 	mace->maccc = maccc;
137 	mp->rx_slot = 0;
138 
139 	psc_write_word(PSC_ENETRD_CMD + PSC_SET0, 0x9800);
140 	psc_write_word(PSC_ENETRD_CMD + PSC_SET1, 0x9800);
141 }
142 
143 /*
144  * Reset the transmit DMA subsystem
145  */
146 
147 static void mace_txdma_reset(struct net_device *dev)
148 {
149 	struct mace_data *mp = netdev_priv(dev);
150 	volatile struct mace *mace = mp->mace;
151 	u8 maccc;
152 
153 	psc_write_word(PSC_ENETWR_CTL, 0x8800);
154 
155 	maccc = mace->maccc;
156 	mace->maccc = maccc & ~ENXMT;
157 
158 	mp->tx_slot = mp->tx_sloti = 0;
159 	mp->tx_count = N_TX_RING;
160 
161 	psc_write_word(PSC_ENETWR_CTL, 0x0400);
162 	mace->maccc = maccc;
163 }
164 
165 /*
166  * Disable DMA
167  */
168 
169 static void mace_dma_off(struct net_device *dev)
170 {
171 	psc_write_word(PSC_ENETRD_CTL, 0x8800);
172 	psc_write_word(PSC_ENETRD_CTL, 0x1000);
173 	psc_write_word(PSC_ENETRD_CMD + PSC_SET0, 0x1100);
174 	psc_write_word(PSC_ENETRD_CMD + PSC_SET1, 0x1100);
175 
176 	psc_write_word(PSC_ENETWR_CTL, 0x8800);
177 	psc_write_word(PSC_ENETWR_CTL, 0x1000);
178 	psc_write_word(PSC_ENETWR_CMD + PSC_SET0, 0x1100);
179 	psc_write_word(PSC_ENETWR_CMD + PSC_SET1, 0x1100);
180 }
181 
182 static const struct net_device_ops mace_netdev_ops = {
183 	.ndo_open		= mace_open,
184 	.ndo_stop		= mace_close,
185 	.ndo_start_xmit		= mace_xmit_start,
186 	.ndo_tx_timeout		= mace_tx_timeout,
187 	.ndo_set_rx_mode	= mace_set_multicast,
188 	.ndo_set_mac_address	= mace_set_address,
189 	.ndo_change_mtu		= eth_change_mtu,
190 	.ndo_validate_addr	= eth_validate_addr,
191 };
192 
193 /*
194  * Not really much of a probe. The hardware table tells us if this
195  * model of Macintrash has a MACE (AV macintoshes)
196  */
197 
198 static int mace_probe(struct platform_device *pdev)
199 {
200 	int j;
201 	struct mace_data *mp;
202 	unsigned char *addr;
203 	struct net_device *dev;
204 	unsigned char checksum = 0;
205 	int err;
206 
207 	dev = alloc_etherdev(PRIV_BYTES);
208 	if (!dev)
209 		return -ENOMEM;
210 
211 	mp = netdev_priv(dev);
212 
213 	mp->device = &pdev->dev;
214 	platform_set_drvdata(pdev, dev);
215 	SET_NETDEV_DEV(dev, &pdev->dev);
216 
217 	dev->base_addr = (u32)MACE_BASE;
218 	mp->mace = MACE_BASE;
219 
220 	dev->irq = IRQ_MAC_MACE;
221 	mp->dma_intr = IRQ_MAC_MACE_DMA;
222 
223 	mp->chipid = mp->mace->chipid_hi << 8 | mp->mace->chipid_lo;
224 
225 	/*
226 	 * The PROM contains 8 bytes which total 0xFF when XOR'd
227 	 * together. Due to the usual peculiar apple brain damage
228 	 * the bytes are spaced out in a strange boundary and the
229 	 * bits are reversed.
230 	 */
231 
232 	addr = MACE_PROM;
233 
234 	for (j = 0; j < 6; ++j) {
235 		u8 v = bitrev8(addr[j<<4]);
236 		checksum ^= v;
237 		dev->dev_addr[j] = v;
238 	}
239 	for (; j < 8; ++j) {
240 		checksum ^= bitrev8(addr[j<<4]);
241 	}
242 
243 	if (checksum != 0xFF) {
244 		free_netdev(dev);
245 		return -ENODEV;
246 	}
247 
248 	dev->netdev_ops		= &mace_netdev_ops;
249 	dev->watchdog_timeo	= TX_TIMEOUT;
250 
251 	printk(KERN_INFO "%s: 68K MACE, hardware address %pM\n",
252 	       dev->name, dev->dev_addr);
253 
254 	err = register_netdev(dev);
255 	if (!err)
256 		return 0;
257 
258 	free_netdev(dev);
259 	return err;
260 }
261 
262 /*
263  * Reset the chip.
264  */
265 
266 static void mace_reset(struct net_device *dev)
267 {
268 	struct mace_data *mp = netdev_priv(dev);
269 	volatile struct mace *mb = mp->mace;
270 	int i;
271 
272 	/* soft-reset the chip */
273 	i = 200;
274 	while (--i) {
275 		mb->biucc = SWRST;
276 		if (mb->biucc & SWRST) {
277 			udelay(10);
278 			continue;
279 		}
280 		break;
281 	}
282 	if (!i) {
283 		printk(KERN_ERR "macmace: cannot reset chip!\n");
284 		return;
285 	}
286 
287 	mb->maccc = 0;	/* turn off tx, rx */
288 	mb->imr = 0xFF;	/* disable all intrs for now */
289 	i = mb->ir;
290 
291 	mb->biucc = XMTSP_64;
292 	mb->utr = RTRD;
293 	mb->fifocc = XMTFW_8 | RCVFW_64 | XMTFWU | RCVFWU;
294 
295 	mb->xmtfc = AUTO_PAD_XMIT; /* auto-pad short frames */
296 	mb->rcvfc = 0;
297 
298 	/* load up the hardware address */
299 	__mace_set_address(dev, dev->dev_addr);
300 
301 	/* clear the multicast filter */
302 	if (mp->chipid == BROKEN_ADDRCHG_REV)
303 		mb->iac = LOGADDR;
304 	else {
305 		mb->iac = ADDRCHG | LOGADDR;
306 		while ((mb->iac & ADDRCHG) != 0)
307 			;
308 	}
309 	for (i = 0; i < 8; ++i)
310 		mb->ladrf = 0;
311 
312 	/* done changing address */
313 	if (mp->chipid != BROKEN_ADDRCHG_REV)
314 		mb->iac = 0;
315 
316 	mb->plscc = PORTSEL_AUI;
317 }
318 
319 /*
320  * Load the address on a mace controller.
321  */
322 
323 static void __mace_set_address(struct net_device *dev, void *addr)
324 {
325 	struct mace_data *mp = netdev_priv(dev);
326 	volatile struct mace *mb = mp->mace;
327 	unsigned char *p = addr;
328 	int i;
329 
330 	/* load up the hardware address */
331 	if (mp->chipid == BROKEN_ADDRCHG_REV)
332 		mb->iac = PHYADDR;
333 	else {
334 		mb->iac = ADDRCHG | PHYADDR;
335 		while ((mb->iac & ADDRCHG) != 0)
336 			;
337 	}
338 	for (i = 0; i < 6; ++i)
339 		mb->padr = dev->dev_addr[i] = p[i];
340 	if (mp->chipid != BROKEN_ADDRCHG_REV)
341 		mb->iac = 0;
342 }
343 
344 static int mace_set_address(struct net_device *dev, void *addr)
345 {
346 	struct mace_data *mp = netdev_priv(dev);
347 	volatile struct mace *mb = mp->mace;
348 	unsigned long flags;
349 	u8 maccc;
350 
351 	local_irq_save(flags);
352 
353 	maccc = mb->maccc;
354 
355 	__mace_set_address(dev, addr);
356 
357 	mb->maccc = maccc;
358 
359 	local_irq_restore(flags);
360 
361 	return 0;
362 }
363 
364 /*
365  * Open the Macintosh MACE. Most of this is playing with the DMA
366  * engine. The ethernet chip is quite friendly.
367  */
368 
369 static int mace_open(struct net_device *dev)
370 {
371 	struct mace_data *mp = netdev_priv(dev);
372 	volatile struct mace *mb = mp->mace;
373 
374 	/* reset the chip */
375 	mace_reset(dev);
376 
377 	if (request_irq(dev->irq, mace_interrupt, 0, dev->name, dev)) {
378 		printk(KERN_ERR "%s: can't get irq %d\n", dev->name, dev->irq);
379 		return -EAGAIN;
380 	}
381 	if (request_irq(mp->dma_intr, mace_dma_intr, 0, dev->name, dev)) {
382 		printk(KERN_ERR "%s: can't get irq %d\n", dev->name, mp->dma_intr);
383 		free_irq(dev->irq, dev);
384 		return -EAGAIN;
385 	}
386 
387 	/* Allocate the DMA ring buffers */
388 
389 	mp->tx_ring = dma_alloc_coherent(mp->device,
390 					 N_TX_RING * MACE_BUFF_SIZE,
391 					 &mp->tx_ring_phys, GFP_KERNEL);
392 	if (mp->tx_ring == NULL)
393 		goto out1;
394 
395 	mp->rx_ring = dma_alloc_coherent(mp->device,
396 					 N_RX_RING * MACE_BUFF_SIZE,
397 					 &mp->rx_ring_phys, GFP_KERNEL);
398 	if (mp->rx_ring == NULL)
399 		goto out2;
400 
401 	mace_dma_off(dev);
402 
403 	/* Not sure what these do */
404 
405 	psc_write_word(PSC_ENETWR_CTL, 0x9000);
406 	psc_write_word(PSC_ENETRD_CTL, 0x9000);
407 	psc_write_word(PSC_ENETWR_CTL, 0x0400);
408 	psc_write_word(PSC_ENETRD_CTL, 0x0400);
409 
410 	mace_rxdma_reset(dev);
411 	mace_txdma_reset(dev);
412 
413 	/* turn it on! */
414 	mb->maccc = ENXMT | ENRCV;
415 	/* enable all interrupts except receive interrupts */
416 	mb->imr = RCVINT;
417 	return 0;
418 
419 out2:
420 	dma_free_coherent(mp->device, N_TX_RING * MACE_BUFF_SIZE,
421 	                  mp->tx_ring, mp->tx_ring_phys);
422 out1:
423 	free_irq(dev->irq, dev);
424 	free_irq(mp->dma_intr, dev);
425 	return -ENOMEM;
426 }
427 
428 /*
429  * Shut down the mace and its interrupt channel
430  */
431 
432 static int mace_close(struct net_device *dev)
433 {
434 	struct mace_data *mp = netdev_priv(dev);
435 	volatile struct mace *mb = mp->mace;
436 
437 	mb->maccc = 0;		/* disable rx and tx	 */
438 	mb->imr = 0xFF;		/* disable all irqs	 */
439 	mace_dma_off(dev);	/* disable rx and tx dma */
440 
441 	return 0;
442 }
443 
444 /*
445  * Transmit a frame
446  */
447 
448 static int mace_xmit_start(struct sk_buff *skb, struct net_device *dev)
449 {
450 	struct mace_data *mp = netdev_priv(dev);
451 	unsigned long flags;
452 
453 	/* Stop the queue since there's only the one buffer */
454 
455 	local_irq_save(flags);
456 	netif_stop_queue(dev);
457 	if (!mp->tx_count) {
458 		printk(KERN_ERR "macmace: tx queue running but no free buffers.\n");
459 		local_irq_restore(flags);
460 		return NETDEV_TX_BUSY;
461 	}
462 	mp->tx_count--;
463 	local_irq_restore(flags);
464 
465 	dev->stats.tx_packets++;
466 	dev->stats.tx_bytes += skb->len;
467 
468 	/* We need to copy into our xmit buffer to take care of alignment and caching issues */
469 	skb_copy_from_linear_data(skb, mp->tx_ring, skb->len);
470 
471 	/* load the Tx DMA and fire it off */
472 
473 	psc_write_long(PSC_ENETWR_ADDR + mp->tx_slot, (u32)  mp->tx_ring_phys);
474 	psc_write_long(PSC_ENETWR_LEN + mp->tx_slot, skb->len);
475 	psc_write_word(PSC_ENETWR_CMD + mp->tx_slot, 0x9800);
476 
477 	mp->tx_slot ^= 0x10;
478 
479 	dev_kfree_skb(skb);
480 
481 	return NETDEV_TX_OK;
482 }
483 
484 static void mace_set_multicast(struct net_device *dev)
485 {
486 	struct mace_data *mp = netdev_priv(dev);
487 	volatile struct mace *mb = mp->mace;
488 	int i;
489 	u32 crc;
490 	u8 maccc;
491 	unsigned long flags;
492 
493 	local_irq_save(flags);
494 	maccc = mb->maccc;
495 	mb->maccc &= ~PROM;
496 
497 	if (dev->flags & IFF_PROMISC) {
498 		mb->maccc |= PROM;
499 	} else {
500 		unsigned char multicast_filter[8];
501 		struct netdev_hw_addr *ha;
502 
503 		if (dev->flags & IFF_ALLMULTI) {
504 			for (i = 0; i < 8; i++) {
505 				multicast_filter[i] = 0xFF;
506 			}
507 		} else {
508 			for (i = 0; i < 8; i++)
509 				multicast_filter[i] = 0;
510 			netdev_for_each_mc_addr(ha, dev) {
511 				crc = ether_crc_le(6, ha->addr);
512 				/* bit number in multicast_filter */
513 				i = crc >> 26;
514 				multicast_filter[i >> 3] |= 1 << (i & 7);
515 			}
516 		}
517 
518 		if (mp->chipid == BROKEN_ADDRCHG_REV)
519 			mb->iac = LOGADDR;
520 		else {
521 			mb->iac = ADDRCHG | LOGADDR;
522 			while ((mb->iac & ADDRCHG) != 0)
523 				;
524 		}
525 		for (i = 0; i < 8; ++i)
526 			mb->ladrf = multicast_filter[i];
527 		if (mp->chipid != BROKEN_ADDRCHG_REV)
528 			mb->iac = 0;
529 	}
530 
531 	mb->maccc = maccc;
532 	local_irq_restore(flags);
533 }
534 
535 static void mace_handle_misc_intrs(struct net_device *dev, int intr)
536 {
537 	struct mace_data *mp = netdev_priv(dev);
538 	volatile struct mace *mb = mp->mace;
539 	static int mace_babbles, mace_jabbers;
540 
541 	if (intr & MPCO)
542 		dev->stats.rx_missed_errors += 256;
543 	dev->stats.rx_missed_errors += mb->mpc;   /* reading clears it */
544 	if (intr & RNTPCO)
545 		dev->stats.rx_length_errors += 256;
546 	dev->stats.rx_length_errors += mb->rntpc; /* reading clears it */
547 	if (intr & CERR)
548 		++dev->stats.tx_heartbeat_errors;
549 	if (intr & BABBLE)
550 		if (mace_babbles++ < 4)
551 			printk(KERN_DEBUG "macmace: babbling transmitter\n");
552 	if (intr & JABBER)
553 		if (mace_jabbers++ < 4)
554 			printk(KERN_DEBUG "macmace: jabbering transceiver\n");
555 }
556 
557 static irqreturn_t mace_interrupt(int irq, void *dev_id)
558 {
559 	struct net_device *dev = (struct net_device *) dev_id;
560 	struct mace_data *mp = netdev_priv(dev);
561 	volatile struct mace *mb = mp->mace;
562 	int intr, fs;
563 	unsigned long flags;
564 
565 	/* don't want the dma interrupt handler to fire */
566 	local_irq_save(flags);
567 
568 	intr = mb->ir; /* read interrupt register */
569 	mace_handle_misc_intrs(dev, intr);
570 
571 	if (intr & XMTINT) {
572 		fs = mb->xmtfs;
573 		if ((fs & XMTSV) == 0) {
574 			printk(KERN_ERR "macmace: xmtfs not valid! (fs=%x)\n", fs);
575 			mace_reset(dev);
576 			/*
577 			 * XXX mace likes to hang the machine after a xmtfs error.
578 			 * This is hard to reproduce, resetting *may* help
579 			 */
580 		}
581 		/* dma should have finished */
582 		if (!mp->tx_count) {
583 			printk(KERN_DEBUG "macmace: tx ring ran out? (fs=%x)\n", fs);
584 		}
585 		/* Update stats */
586 		if (fs & (UFLO|LCOL|LCAR|RTRY)) {
587 			++dev->stats.tx_errors;
588 			if (fs & LCAR)
589 				++dev->stats.tx_carrier_errors;
590 			else if (fs & (UFLO|LCOL|RTRY)) {
591 				++dev->stats.tx_aborted_errors;
592 				if (mb->xmtfs & UFLO) {
593 					printk(KERN_ERR "%s: DMA underrun.\n", dev->name);
594 					dev->stats.tx_fifo_errors++;
595 					mace_txdma_reset(dev);
596 				}
597 			}
598 		}
599 	}
600 
601 	if (mp->tx_count)
602 		netif_wake_queue(dev);
603 
604 	local_irq_restore(flags);
605 
606 	return IRQ_HANDLED;
607 }
608 
609 static void mace_tx_timeout(struct net_device *dev)
610 {
611 	struct mace_data *mp = netdev_priv(dev);
612 	volatile struct mace *mb = mp->mace;
613 	unsigned long flags;
614 
615 	local_irq_save(flags);
616 
617 	/* turn off both tx and rx and reset the chip */
618 	mb->maccc = 0;
619 	printk(KERN_ERR "macmace: transmit timeout - resetting\n");
620 	mace_txdma_reset(dev);
621 	mace_reset(dev);
622 
623 	/* restart rx dma */
624 	mace_rxdma_reset(dev);
625 
626 	mp->tx_count = N_TX_RING;
627 	netif_wake_queue(dev);
628 
629 	/* turn it on! */
630 	mb->maccc = ENXMT | ENRCV;
631 	/* enable all interrupts except receive interrupts */
632 	mb->imr = RCVINT;
633 
634 	local_irq_restore(flags);
635 }
636 
637 /*
638  * Handle a newly arrived frame
639  */
640 
641 static void mace_dma_rx_frame(struct net_device *dev, struct mace_frame *mf)
642 {
643 	struct sk_buff *skb;
644 	unsigned int frame_status = mf->rcvsts;
645 
646 	if (frame_status & (RS_OFLO | RS_CLSN | RS_FRAMERR | RS_FCSERR)) {
647 		dev->stats.rx_errors++;
648 		if (frame_status & RS_OFLO) {
649 			printk(KERN_DEBUG "%s: fifo overflow.\n", dev->name);
650 			dev->stats.rx_fifo_errors++;
651 		}
652 		if (frame_status & RS_CLSN)
653 			dev->stats.collisions++;
654 		if (frame_status & RS_FRAMERR)
655 			dev->stats.rx_frame_errors++;
656 		if (frame_status & RS_FCSERR)
657 			dev->stats.rx_crc_errors++;
658 	} else {
659 		unsigned int frame_length = mf->rcvcnt + ((frame_status & 0x0F) << 8 );
660 
661 		skb = netdev_alloc_skb(dev, frame_length + 2);
662 		if (!skb) {
663 			dev->stats.rx_dropped++;
664 			return;
665 		}
666 		skb_reserve(skb, 2);
667 		memcpy(skb_put(skb, frame_length), mf->data, frame_length);
668 
669 		skb->protocol = eth_type_trans(skb, dev);
670 		netif_rx(skb);
671 		dev->stats.rx_packets++;
672 		dev->stats.rx_bytes += frame_length;
673 	}
674 }
675 
676 /*
677  * The PSC has passed us a DMA interrupt event.
678  */
679 
680 static irqreturn_t mace_dma_intr(int irq, void *dev_id)
681 {
682 	struct net_device *dev = (struct net_device *) dev_id;
683 	struct mace_data *mp = netdev_priv(dev);
684 	int left, head;
685 	u16 status;
686 	u32 baka;
687 
688 	/* Not sure what this does */
689 
690 	while ((baka = psc_read_long(PSC_MYSTERY)) != psc_read_long(PSC_MYSTERY));
691 	if (!(baka & 0x60000000)) return IRQ_NONE;
692 
693 	/*
694 	 * Process the read queue
695 	 */
696 
697 	status = psc_read_word(PSC_ENETRD_CTL);
698 
699 	if (status & 0x2000) {
700 		mace_rxdma_reset(dev);
701 	} else if (status & 0x0100) {
702 		psc_write_word(PSC_ENETRD_CMD + mp->rx_slot, 0x1100);
703 
704 		left = psc_read_long(PSC_ENETRD_LEN + mp->rx_slot);
705 		head = N_RX_RING - left;
706 
707 		/* Loop through the ring buffer and process new packages */
708 
709 		while (mp->rx_tail < head) {
710 			mace_dma_rx_frame(dev, (struct mace_frame*) (mp->rx_ring
711 				+ (mp->rx_tail * MACE_BUFF_SIZE)));
712 			mp->rx_tail++;
713 		}
714 
715 		/* If we're out of buffers in this ring then switch to */
716 		/* the other set, otherwise just reactivate this one.  */
717 
718 		if (!left) {
719 			mace_load_rxdma_base(dev, mp->rx_slot);
720 			mp->rx_slot ^= 0x10;
721 		} else {
722 			psc_write_word(PSC_ENETRD_CMD + mp->rx_slot, 0x9800);
723 		}
724 	}
725 
726 	/*
727 	 * Process the write queue
728 	 */
729 
730 	status = psc_read_word(PSC_ENETWR_CTL);
731 
732 	if (status & 0x2000) {
733 		mace_txdma_reset(dev);
734 	} else if (status & 0x0100) {
735 		psc_write_word(PSC_ENETWR_CMD + mp->tx_sloti, 0x0100);
736 		mp->tx_sloti ^= 0x10;
737 		mp->tx_count++;
738 	}
739 	return IRQ_HANDLED;
740 }
741 
742 MODULE_LICENSE("GPL");
743 MODULE_DESCRIPTION("Macintosh MACE ethernet driver");
744 MODULE_ALIAS("platform:macmace");
745 
746 static int mac_mace_device_remove(struct platform_device *pdev)
747 {
748 	struct net_device *dev = platform_get_drvdata(pdev);
749 	struct mace_data *mp = netdev_priv(dev);
750 
751 	unregister_netdev(dev);
752 
753 	free_irq(dev->irq, dev);
754 	free_irq(IRQ_MAC_MACE_DMA, dev);
755 
756 	dma_free_coherent(mp->device, N_RX_RING * MACE_BUFF_SIZE,
757 	                  mp->rx_ring, mp->rx_ring_phys);
758 	dma_free_coherent(mp->device, N_TX_RING * MACE_BUFF_SIZE,
759 	                  mp->tx_ring, mp->tx_ring_phys);
760 
761 	free_netdev(dev);
762 
763 	return 0;
764 }
765 
766 static struct platform_driver mac_mace_driver = {
767 	.probe  = mace_probe,
768 	.remove = mac_mace_device_remove,
769 	.driver	= {
770 		.name	= mac_mace_string,
771 	},
772 };
773 
774 static int __init mac_mace_init_module(void)
775 {
776 	if (!MACH_IS_MAC)
777 		return -ENODEV;
778 
779 	return platform_driver_register(&mac_mace_driver);
780 }
781 
782 static void __exit mac_mace_cleanup_module(void)
783 {
784 	platform_driver_unregister(&mac_mace_driver);
785 }
786 
787 module_init(mac_mace_init_module);
788 module_exit(mac_mace_cleanup_module);
789