xref: /openbmc/u-boot/drivers/net/dm9000x.c (revision 461fa68d)
1 /*
2   dm9000.c: Version 1.2 12/15/2003
3 
4 	A Davicom DM9000 ISA NIC fast Ethernet driver for Linux.
5 	Copyright (C) 1997  Sten Wang
6 
7 	This program is free software; you can redistribute it and/or
8 	modify it under the terms of the GNU General Public License
9 	as published by the Free Software Foundation; either version 2
10 	of the License, or (at your option) any later version.
11 
12 	This program is distributed in the hope that it will be useful,
13 	but WITHOUT ANY WARRANTY; without even the implied warranty of
14 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 	GNU General Public License for more details.
16 
17   (C)Copyright 1997-1998 DAVICOM Semiconductor,Inc. All Rights Reserved.
18 
19 V0.11	06/20/2001	REG_0A bit3=1, default enable BP with DA match
20 	06/22/2001	Support DM9801 progrmming
21 			E3: R25 = ((R24 + NF) & 0x00ff) | 0xf000
22 			E4: R25 = ((R24 + NF) & 0x00ff) | 0xc200
23 		R17 = (R17 & 0xfff0) | NF + 3
24 			E5: R25 = ((R24 + NF - 3) & 0x00ff) | 0xc200
25 		R17 = (R17 & 0xfff0) | NF
26 
27 v1.00			modify by simon 2001.9.5
28 	                change for kernel 2.4.x
29 
30 v1.1   11/09/2001	fix force mode bug
31 
32 v1.2   03/18/2003       Weilun Huang <weilun_huang@davicom.com.tw>:
33 			Fixed phy reset.
34 			Added tx/rx 32 bit mode.
35 			Cleaned up for kernel merge.
36 
37 --------------------------------------
38 
39        12/15/2003       Initial port to u-boot by
40        			Sascha Hauer <saschahauer@web.de>
41 
42        06/03/2008	Remy Bohmer <linux@bohmer.net>
43 			- Fixed the driver to work with DM9000A.
44 			  (check on ISR receive status bit before reading the
45 			  FIFO as described in DM9000 programming guide and
46 			  application notes)
47 			- Added autodetect of databus width.
48 			- Made debug code compile again.
49 			- Adapt eth_send such that it matches the DM9000*
50 			  application notes. Needed to make it work properly
51 			  for DM9000A.
52 			- Adapted reset procedure to match DM9000 application
53 			  notes (i.e. double reset)
54 			- some minor code cleanups
55 			These changes are tested with DM9000{A,EP,E} together
56 			with a 200MHz Atmel AT91SAM92161 core
57 
58 TODO: Homerun NIC and longrun NIC are not functional, only internal at the
59       moment.
60 */
61 
62 #include <common.h>
63 #include <command.h>
64 #include <net.h>
65 #include <asm/io.h>
66 
67 #include "dm9000x.h"
68 
69 /* Board/System/Debug information/definition ---------------- */
70 
71 #define DM9801_NOISE_FLOOR	0x08
72 #define DM9802_NOISE_FLOOR	0x05
73 
74 /* #define CONFIG_DM9000_DEBUG */
75 
76 #ifdef CONFIG_DM9000_DEBUG
77 #define DM9000_DBG(fmt,args...) printf(fmt, ##args)
78 #define DM9000_DMP_PACKET(func,packet,length)  \
79 	do { \
80 		int i; 							\
81 		printf(func ": length: %d\n", length);			\
82 		for (i = 0; i < length; i++) {				\
83 			if (i % 8 == 0)					\
84 				printf("\n%s: %02x: ", func, i);	\
85 			printf("%02x ", ((unsigned char *) packet)[i]);	\
86 		} printf("\n");						\
87 	} while(0)
88 #else
89 #define DM9000_DBG(fmt,args...)
90 #define DM9000_DMP_PACKET(func,packet,length)
91 #endif
92 
93 enum DM9000_PHY_mode { DM9000_10MHD = 0, DM9000_100MHD =
94 	    1, DM9000_10MFD = 4, DM9000_100MFD = 5, DM9000_AUTO =
95 	    8, DM9000_1M_HPNA = 0x10
96 };
97 enum DM9000_NIC_TYPE { FASTETHER_NIC = 0, HOMERUN_NIC = 1, LONGRUN_NIC = 2
98 };
99 
100 /* Structure/enum declaration ------------------------------- */
101 typedef struct board_info {
102 	u32 runt_length_counter;	/* counter: RX length < 64byte */
103 	u32 long_length_counter;	/* counter: RX length > 1514byte */
104 	u32 reset_counter;	/* counter: RESET */
105 	u32 reset_tx_timeout;	/* RESET caused by TX Timeout */
106 	u32 reset_rx_status;	/* RESET caused by RX Statsus wrong */
107 	u16 tx_pkt_cnt;
108 	u16 queue_start_addr;
109 	u16 dbug_cnt;
110 	u8 phy_addr;
111 	u8 device_wait_reset;	/* device state */
112 	u8 nic_type;		/* NIC type */
113 	unsigned char srom[128];
114 	void (*outblk)(volatile void *data_ptr, int count);
115 	void (*inblk)(void *data_ptr, int count);
116 	void (*rx_status)(u16 *RxStatus, u16 *RxLen);
117 } board_info_t;
118 static board_info_t dm9000_info;
119 
120 /* For module input parameter */
121 static int media_mode = DM9000_AUTO;
122 static u8 nfloor = 0;
123 
124 /* function declaration ------------------------------------- */
125 int eth_init(bd_t * bd);
126 int eth_send(volatile void *, int);
127 int eth_rx(void);
128 void eth_halt(void);
129 static int dm9000_probe(void);
130 static u16 phy_read(int);
131 static void phy_write(int, u16);
132 u16 read_srom_word(int);
133 static u8 DM9000_ior(int);
134 static void DM9000_iow(int reg, u8 value);
135 
136 /* DM9000 network board routine ---------------------------- */
137 
138 #define DM9000_outb(d,r) ( *(volatile u8 *)r = d )
139 #define DM9000_outw(d,r) ( *(volatile u16 *)r = d )
140 #define DM9000_outl(d,r) ( *(volatile u32 *)r = d )
141 #define DM9000_inb(r) (*(volatile u8 *)r)
142 #define DM9000_inw(r) (*(volatile u16 *)r)
143 #define DM9000_inl(r) (*(volatile u32 *)r)
144 
145 #ifdef CONFIG_DM9000_DEBUG
146 static void
147 dump_regs(void)
148 {
149 	DM9000_DBG("\n");
150 	DM9000_DBG("NCR   (0x00): %02x\n", DM9000_ior(0));
151 	DM9000_DBG("NSR   (0x01): %02x\n", DM9000_ior(1));
152 	DM9000_DBG("TCR   (0x02): %02x\n", DM9000_ior(2));
153 	DM9000_DBG("TSRI  (0x03): %02x\n", DM9000_ior(3));
154 	DM9000_DBG("TSRII (0x04): %02x\n", DM9000_ior(4));
155 	DM9000_DBG("RCR   (0x05): %02x\n", DM9000_ior(5));
156 	DM9000_DBG("RSR   (0x06): %02x\n", DM9000_ior(6));
157 	DM9000_DBG("ISR   (0xFE): %02x\n", DM9000_ior(DM9000_ISR));
158 	DM9000_DBG("\n");
159 }
160 #endif
161 
162 static void dm9000_outblk_8bit(volatile void *data_ptr, int count)
163 {
164 	int i;
165 	for (i = 0; i < count; i++)
166 		DM9000_outb((((u8 *) data_ptr)[i] & 0xff), DM9000_DATA);
167 }
168 
169 static void dm9000_outblk_16bit(volatile void *data_ptr, int count)
170 {
171 	int i;
172 	u32 tmplen = (count + 1) / 2;
173 
174 	for (i = 0; i < tmplen; i++)
175 		DM9000_outw(((u16 *) data_ptr)[i], DM9000_DATA);
176 }
177 static void dm9000_outblk_32bit(volatile void *data_ptr, int count)
178 {
179 	int i;
180 	u32 tmplen = (count + 3) / 4;
181 
182 	for (i = 0; i < tmplen; i++)
183 		DM9000_outl(((u32 *) data_ptr)[i], DM9000_DATA);
184 }
185 
186 static void dm9000_inblk_8bit(void *data_ptr, int count)
187 {
188 	int i;
189 	for (i = 0; i < count; i++)
190 		((u8 *) data_ptr)[i] = DM9000_inb(DM9000_DATA);
191 }
192 
193 static void dm9000_inblk_16bit(void *data_ptr, int count)
194 {
195 	int i;
196 	u32 tmplen = (count + 1) / 2;
197 
198 	for (i = 0; i < tmplen; i++)
199 		((u16 *) data_ptr)[i] = DM9000_inw(DM9000_DATA);
200 }
201 static void dm9000_inblk_32bit(void *data_ptr, int count)
202 {
203 	int i;
204 	u32 tmplen = (count + 3) / 4;
205 
206 	for (i = 0; i < tmplen; i++)
207 		((u32 *) data_ptr)[i] = DM9000_inl(DM9000_DATA);
208 }
209 
210 static void dm9000_rx_status_32bit(u16 *RxStatus, u16 *RxLen)
211 {
212 	u32 tmpdata;
213 
214 	DM9000_outb(DM9000_MRCMD, DM9000_IO);
215 
216 	tmpdata = DM9000_inl(DM9000_DATA);
217 	*RxStatus = tmpdata;
218 	*RxLen = tmpdata >> 16;
219 }
220 
221 static void dm9000_rx_status_16bit(u16 *RxStatus, u16 *RxLen)
222 {
223 	DM9000_outb(DM9000_MRCMD, DM9000_IO);
224 
225 	*RxStatus = DM9000_inw(DM9000_DATA);
226 	*RxLen = DM9000_inw(DM9000_DATA);
227 }
228 
229 static void dm9000_rx_status_8bit(u16 *RxStatus, u16 *RxLen)
230 {
231 	DM9000_outb(DM9000_MRCMD, DM9000_IO);
232 
233 	*RxStatus = DM9000_inb(DM9000_DATA) + (DM9000_inb(DM9000_DATA) << 8);
234 	*RxLen = DM9000_inb(DM9000_DATA) + (DM9000_inb(DM9000_DATA) << 8);
235 }
236 
237 /*
238   Search DM9000 board, allocate space and register it
239 */
240 int
241 dm9000_probe(void)
242 {
243 	u32 id_val;
244 	id_val = DM9000_ior(DM9000_VIDL);
245 	id_val |= DM9000_ior(DM9000_VIDH) << 8;
246 	id_val |= DM9000_ior(DM9000_PIDL) << 16;
247 	id_val |= DM9000_ior(DM9000_PIDH) << 24;
248 	if (id_val == DM9000_ID) {
249 		printf("dm9000 i/o: 0x%x, id: 0x%x \n", CONFIG_DM9000_BASE,
250 		       id_val);
251 		return 0;
252 	} else {
253 		printf("dm9000 not found at 0x%08x id: 0x%08x\n",
254 		       CONFIG_DM9000_BASE, id_val);
255 		return -1;
256 	}
257 }
258 
259 /* Set PHY operationg mode
260 */
261 static void
262 set_PHY_mode(void)
263 {
264 	u16 phy_reg4 = 0x01e1, phy_reg0 = 0x1000;
265 	if (!(media_mode & DM9000_AUTO)) {
266 		switch (media_mode) {
267 		case DM9000_10MHD:
268 			phy_reg4 = 0x21;
269 			phy_reg0 = 0x0000;
270 			break;
271 		case DM9000_10MFD:
272 			phy_reg4 = 0x41;
273 			phy_reg0 = 0x1100;
274 			break;
275 		case DM9000_100MHD:
276 			phy_reg4 = 0x81;
277 			phy_reg0 = 0x2000;
278 			break;
279 		case DM9000_100MFD:
280 			phy_reg4 = 0x101;
281 			phy_reg0 = 0x3100;
282 			break;
283 		}
284 		phy_write(4, phy_reg4);	/* Set PHY media mode */
285 		phy_write(0, phy_reg0);	/*  Tmp */
286 	}
287 	DM9000_iow(DM9000_GPCR, 0x01);	/* Let GPIO0 output */
288 	DM9000_iow(DM9000_GPR, 0x00);	/* Enable PHY */
289 }
290 
291 /*
292 	Init HomeRun DM9801
293 */
294 static void
295 program_dm9801(u16 HPNA_rev)
296 {
297 	__u16 reg16, reg17, reg24, reg25;
298 	if (!nfloor)
299 		nfloor = DM9801_NOISE_FLOOR;
300 	reg16 = phy_read(16);
301 	reg17 = phy_read(17);
302 	reg24 = phy_read(24);
303 	reg25 = phy_read(25);
304 	switch (HPNA_rev) {
305 	case 0xb900:		/* DM9801 E3 */
306 		reg16 |= 0x1000;
307 		reg25 = ((reg24 + nfloor) & 0x00ff) | 0xf000;
308 		break;
309 	case 0xb901:		/* DM9801 E4 */
310 		reg25 = ((reg24 + nfloor) & 0x00ff) | 0xc200;
311 		reg17 = (reg17 & 0xfff0) + nfloor + 3;
312 		break;
313 	case 0xb902:		/* DM9801 E5 */
314 	case 0xb903:		/* DM9801 E6 */
315 	default:
316 		reg16 |= 0x1000;
317 		reg25 = ((reg24 + nfloor - 3) & 0x00ff) | 0xc200;
318 		reg17 = (reg17 & 0xfff0) + nfloor;
319 	}
320 	phy_write(16, reg16);
321 	phy_write(17, reg17);
322 	phy_write(25, reg25);
323 }
324 
325 /*
326 	Init LongRun DM9802
327 */
328 static void
329 program_dm9802(void)
330 {
331 	__u16 reg25;
332 	if (!nfloor)
333 		nfloor = DM9802_NOISE_FLOOR;
334 	reg25 = phy_read(25);
335 	reg25 = (reg25 & 0xff00) + nfloor;
336 	phy_write(25, reg25);
337 }
338 
339 /* Identify NIC type
340 */
341 static void
342 identify_nic(void)
343 {
344 	struct board_info *db = &dm9000_info;
345 	u16 phy_reg3;
346 	DM9000_iow(DM9000_NCR, NCR_EXT_PHY);
347 	phy_reg3 = phy_read(3);
348 	switch (phy_reg3 & 0xfff0) {
349 	case 0xb900:
350 		if (phy_read(31) == 0x4404) {
351 			db->nic_type = HOMERUN_NIC;
352 			program_dm9801(phy_reg3);
353 			DM9000_DBG("found homerun NIC\n");
354 		} else {
355 			db->nic_type = LONGRUN_NIC;
356 			DM9000_DBG("found longrun NIC\n");
357 			program_dm9802();
358 		}
359 		break;
360 	default:
361 		db->nic_type = FASTETHER_NIC;
362 		break;
363 	}
364 	DM9000_iow(DM9000_NCR, 0);
365 }
366 
367 /* General Purpose dm9000 reset routine */
368 static void
369 dm9000_reset(void)
370 {
371 	DM9000_DBG("resetting DM9000\n");
372 
373 	/* Reset DM9000,
374 	   see DM9000 Application Notes V1.22 Jun 11, 2004 page 29 */
375 
376 	/* DEBUG: Make all GPIO pins outputs */
377 	DM9000_iow(DM9000_GPCR, 0x0F);
378 	/* Step 1: Power internal PHY by writing 0 to GPIO0 pin */
379 	DM9000_iow(DM9000_GPR, 0);
380 	/* Step 2: Software reset */
381 	DM9000_iow(DM9000_NCR, 3);
382 
383 	do {
384 		DM9000_DBG("resetting the DM9000, 1st reset\n");
385 		udelay(25); /* Wait at least 20 us */
386 	} while (DM9000_ior(DM9000_NCR) & 1);
387 
388 	DM9000_iow(DM9000_NCR, 0);
389 	DM9000_iow(DM9000_NCR, 3); /* Issue a second reset */
390 
391 	do {
392 		DM9000_DBG("resetting the DM9000, 2nd reset\n");
393 		udelay(25); /* Wait at least 20 us */
394 	} while (DM9000_ior(DM9000_NCR) & 1);
395 
396 	/* Check whether the ethernet controller is present */
397 	if ((DM9000_ior(DM9000_PIDL) != 0x0) ||
398 	    (DM9000_ior(DM9000_PIDH) != 0x90))
399 		printf("ERROR: resetting DM9000 -> not responding\n");
400 }
401 
402 /* Initilize dm9000 board
403 */
404 int
405 eth_init(bd_t * bd)
406 {
407 	int i, oft, lnk;
408 	u8 io_mode;
409 	struct board_info *db = &dm9000_info;
410 
411 	DM9000_DBG("eth_init()\n");
412 
413 	/* RESET device */
414 	dm9000_reset();
415 	dm9000_probe();
416 
417 	/* Auto-detect 8/16/32 bit mode, ISR Bit 6+7 indicate bus width */
418 	io_mode = DM9000_ior(DM9000_ISR) >> 6;
419 
420 	switch (io_mode) {
421 	case 0x0:  /* 16-bit mode */
422 		printf("DM9000: running in 16 bit mode\n");
423 		db->outblk    = dm9000_outblk_16bit;
424 		db->inblk     = dm9000_inblk_16bit;
425 		db->rx_status = dm9000_rx_status_16bit;
426 		break;
427 	case 0x01:  /* 32-bit mode */
428 		printf("DM9000: running in 32 bit mode\n");
429 		db->outblk    = dm9000_outblk_32bit;
430 		db->inblk     = dm9000_inblk_32bit;
431 		db->rx_status = dm9000_rx_status_32bit;
432 		break;
433 	case 0x02: /* 8 bit mode */
434 		printf("DM9000: running in 8 bit mode\n");
435 		db->outblk    = dm9000_outblk_8bit;
436 		db->inblk     = dm9000_inblk_8bit;
437 		db->rx_status = dm9000_rx_status_8bit;
438 		break;
439 	default:
440 		/* Assume 8 bit mode, will probably not work anyway */
441 		printf("DM9000: Undefined IO-mode:0x%x\n", io_mode);
442 		db->outblk    = dm9000_outblk_8bit;
443 		db->inblk     = dm9000_inblk_8bit;
444 		db->rx_status = dm9000_rx_status_8bit;
445 		break;
446 	}
447 
448 	/* NIC Type: FASTETHER, HOMERUN, LONGRUN */
449 	identify_nic();
450 
451 	/* GPIO0 on pre-activate PHY */
452 	DM9000_iow(DM9000_GPR, 0x00);	/*REG_1F bit0 activate phyxcer */
453 
454 	/* Set PHY */
455 	set_PHY_mode();
456 
457 	/* Program operating register, only intern phy supported by now */
458 	DM9000_iow(DM9000_NCR, 0x0);
459 	/* TX Polling clear */
460 	DM9000_iow(DM9000_TCR, 0);
461 	/* Less 3Kb, 200us */
462 	DM9000_iow(DM9000_BPTR, 0x3f);
463 	/* Flow Control : High/Low Water */
464 	DM9000_iow(DM9000_FCTR, FCTR_HWOT(3) | FCTR_LWOT(8));
465 	/* SH FIXME: This looks strange! Flow Control */
466 	DM9000_iow(DM9000_FCR, 0x0);
467 	/* Special Mode */
468 	DM9000_iow(DM9000_SMCR, 0);
469 	/* clear TX status */
470 	DM9000_iow(DM9000_NSR, NSR_WAKEST | NSR_TX2END | NSR_TX1END);
471 	/* Clear interrupt status */
472 	DM9000_iow(DM9000_ISR, 0x0f);
473 
474 	/* Set Node address */
475 #ifndef CONFIG_AT91SAM9261EK
476 	for (i = 0; i < 6; i++)
477 		((u16 *) bd->bi_enetaddr)[i] = read_srom_word(i);
478 #endif
479 
480 	if (is_zero_ether_addr(bd->bi_enetaddr) ||
481 	    is_multicast_ether_addr(bd->bi_enetaddr)) {
482 		/* try reading from environment */
483 		u8 i;
484 		char *s, *e;
485 		s = getenv ("ethaddr");
486 		for (i = 0; i < 6; ++i) {
487 			bd->bi_enetaddr[i] = s ?
488 				simple_strtoul (s, &e, 16) : 0;
489 			if (s)
490 				s = (*e) ? e + 1 : e;
491 		}
492 	}
493 
494 	printf("MAC: %02x:%02x:%02x:%02x:%02x:%02x\n", bd->bi_enetaddr[0],
495 	       bd->bi_enetaddr[1], bd->bi_enetaddr[2], bd->bi_enetaddr[3],
496 	       bd->bi_enetaddr[4], bd->bi_enetaddr[5]);
497 	for (i = 0, oft = 0x10; i < 6; i++, oft++)
498 		DM9000_iow(oft, bd->bi_enetaddr[i]);
499 	for (i = 0, oft = 0x16; i < 8; i++, oft++)
500 		DM9000_iow(oft, 0xff);
501 
502 	/* read back mac, just to be sure */
503 	for (i = 0, oft = 0x10; i < 6; i++, oft++)
504 		DM9000_DBG("%02x:", DM9000_ior(oft));
505 	DM9000_DBG("\n");
506 
507 	/* Activate DM9000 */
508 	/* RX enable */
509 	DM9000_iow(DM9000_RCR, RCR_DIS_LONG | RCR_DIS_CRC | RCR_RXEN);
510 	/* Enable TX/RX interrupt mask */
511 	DM9000_iow(DM9000_IMR, IMR_PAR);
512 
513 	i = 0;
514 	while (!(phy_read(1) & 0x20)) {	/* autonegation complete bit */
515 		udelay(1000);
516 		i++;
517 		if (i == 10000) {
518 			printf("could not establish link\n");
519 			return 0;
520 		}
521 	}
522 
523 	/* see what we've got */
524 	lnk = phy_read(17) >> 12;
525 	printf("operating at ");
526 	switch (lnk) {
527 	case 1:
528 		printf("10M half duplex ");
529 		break;
530 	case 2:
531 		printf("10M full duplex ");
532 		break;
533 	case 4:
534 		printf("100M half duplex ");
535 		break;
536 	case 8:
537 		printf("100M full duplex ");
538 		break;
539 	default:
540 		printf("unknown: %d ", lnk);
541 		break;
542 	}
543 	printf("mode\n");
544 	return 0;
545 }
546 
547 /*
548   Hardware start transmission.
549   Send a packet to media from the upper layer.
550 */
551 int
552 eth_send(volatile void *packet, int length)
553 {
554 	int tmo;
555 	struct board_info *db = &dm9000_info;
556 
557 	DM9000_DMP_PACKET("eth_send", packet, length);
558 
559 	DM9000_iow(DM9000_ISR, IMR_PTM); /* Clear Tx bit in ISR */
560 
561 	/* Move data to DM9000 TX RAM */
562 	DM9000_outb(DM9000_MWCMD, DM9000_IO); /* Prepare for TX-data */
563 
564 	/* push the data to the TX-fifo */
565 	(db->outblk)(packet, length);
566 
567 	/* Set TX length to DM9000 */
568 	DM9000_iow(DM9000_TXPLL, length & 0xff);
569 	DM9000_iow(DM9000_TXPLH, (length >> 8) & 0xff);
570 
571 	/* Issue TX polling command */
572 	DM9000_iow(DM9000_TCR, TCR_TXREQ); /* Cleared after TX complete */
573 
574 	/* wait for end of transmission */
575 	tmo = get_timer(0) + 5 * CFG_HZ;
576 	while ( !(DM9000_ior(DM9000_NSR) & (NSR_TX1END | NSR_TX2END)) ||
577 		!(DM9000_ior(DM9000_ISR) & IMR_PTM) ) {
578 		if (get_timer(0) >= tmo) {
579 			printf("transmission timeout\n");
580 			break;
581 		}
582 	}
583 	DM9000_iow(DM9000_ISR, IMR_PTM); /* Clear Tx bit in ISR */
584 
585 	DM9000_DBG("transmit done\n\n");
586 	return 0;
587 }
588 
589 /*
590   Stop the interface.
591   The interface is stopped when it is brought.
592 */
593 void
594 eth_halt(void)
595 {
596 	DM9000_DBG("eth_halt\n");
597 
598 	/* RESET devie */
599 	phy_write(0, 0x8000);	/* PHY RESET */
600 	DM9000_iow(DM9000_GPR, 0x01);	/* Power-Down PHY */
601 	DM9000_iow(DM9000_IMR, 0x80);	/* Disable all interrupt */
602 	DM9000_iow(DM9000_RCR, 0x00);	/* Disable RX */
603 }
604 
605 /*
606   Received a packet and pass to upper layer
607 */
608 int
609 eth_rx(void)
610 {
611 	u8 rxbyte, *rdptr = (u8 *) NetRxPackets[0];
612 	u16 RxStatus, RxLen = 0;
613 	struct board_info *db = &dm9000_info;
614 
615 	/* Check packet ready or not, we must check
616 	   the ISR status first for DM9000A */
617 	if (!(DM9000_ior(DM9000_ISR) & 0x01)) /* Rx-ISR bit must be set. */
618 		return 0;
619 
620 	DM9000_iow(DM9000_ISR, 0x01); /* clear PR status latched in bit 0 */
621 
622 	/* There is _at least_ 1 package in the fifo, read them all */
623 	for (;;) {
624 		DM9000_ior(DM9000_MRCMDX);	/* Dummy read */
625 
626 		/* Get most updated data,
627 		   only look at bits 0:1, See application notes DM9000 */
628 		rxbyte = DM9000_inb(DM9000_DATA) & 0x03;
629 
630 		/* Status check: this byte must be 0 or 1 */
631 		if (rxbyte > DM9000_PKT_RDY) {
632 			DM9000_iow(DM9000_RCR, 0x00);	/* Stop Device */
633 			DM9000_iow(DM9000_ISR, 0x80);	/* Stop INT request */
634 			printf("DM9000 error: status check fail: 0x%x\n",
635 				rxbyte);
636 			return 0;
637 		}
638 
639 		if (rxbyte != DM9000_PKT_RDY)
640 			return 0; /* No packet received, ignore */
641 
642 		DM9000_DBG("receiving packet\n");
643 
644 		/* A packet ready now  & Get status/length */
645 		(db->rx_status)(&RxStatus, &RxLen);
646 
647 		DM9000_DBG("rx status: 0x%04x rx len: %d\n", RxStatus, RxLen);
648 
649 		/* Move data from DM9000 */
650 		/* Read received packet from RX SRAM */
651 		(db->inblk)(rdptr, RxLen);
652 
653 		if ((RxStatus & 0xbf00) || (RxLen < 0x40)
654 			|| (RxLen > DM9000_PKT_MAX)) {
655 			if (RxStatus & 0x100) {
656 				printf("rx fifo error\n");
657 			}
658 			if (RxStatus & 0x200) {
659 				printf("rx crc error\n");
660 			}
661 			if (RxStatus & 0x8000) {
662 				printf("rx length error\n");
663 			}
664 			if (RxLen > DM9000_PKT_MAX) {
665 				printf("rx length too big\n");
666 				dm9000_reset();
667 			}
668 		} else {
669 			DM9000_DMP_PACKET("eth_rx", rdptr, RxLen);
670 
671 			DM9000_DBG("passing packet to upper layer\n");
672 			NetReceive(NetRxPackets[0], RxLen);
673 		}
674 	}
675 	return 0;
676 }
677 
678 /*
679   Read a word data from SROM
680 */
681 u16
682 read_srom_word(int offset)
683 {
684 	DM9000_iow(DM9000_EPAR, offset);
685 	DM9000_iow(DM9000_EPCR, 0x4);
686 	udelay(8000);
687 	DM9000_iow(DM9000_EPCR, 0x0);
688 	return (DM9000_ior(DM9000_EPDRL) + (DM9000_ior(DM9000_EPDRH) << 8));
689 }
690 
691 void
692 write_srom_word(int offset, u16 val)
693 {
694 	DM9000_iow(DM9000_EPAR, offset);
695 	DM9000_iow(DM9000_EPDRH, ((val >> 8) & 0xff));
696 	DM9000_iow(DM9000_EPDRL, (val & 0xff));
697 	DM9000_iow(DM9000_EPCR, 0x12);
698 	udelay(8000);
699 	DM9000_iow(DM9000_EPCR, 0);
700 }
701 
702 
703 /*
704    Read a byte from I/O port
705 */
706 static u8
707 DM9000_ior(int reg)
708 {
709 	DM9000_outb(reg, DM9000_IO);
710 	return DM9000_inb(DM9000_DATA);
711 }
712 
713 /*
714    Write a byte to I/O port
715 */
716 static void
717 DM9000_iow(int reg, u8 value)
718 {
719 	DM9000_outb(reg, DM9000_IO);
720 	DM9000_outb(value, DM9000_DATA);
721 }
722 
723 /*
724    Read a word from phyxcer
725 */
726 static u16
727 phy_read(int reg)
728 {
729 	u16 val;
730 
731 	/* Fill the phyxcer register into REG_0C */
732 	DM9000_iow(DM9000_EPAR, DM9000_PHY | reg);
733 	DM9000_iow(DM9000_EPCR, 0xc);	/* Issue phyxcer read command */
734 	udelay(100);			/* Wait read complete */
735 	DM9000_iow(DM9000_EPCR, 0x0);	/* Clear phyxcer read command */
736 	val = (DM9000_ior(DM9000_EPDRH) << 8) | DM9000_ior(DM9000_EPDRL);
737 
738 	/* The read data keeps on REG_0D & REG_0E */
739 	DM9000_DBG("phy_read(0x%x): 0x%x\n", reg, val);
740 	return val;
741 }
742 
743 /*
744    Write a word to phyxcer
745 */
746 static void
747 phy_write(int reg, u16 value)
748 {
749 
750 	/* Fill the phyxcer register into REG_0C */
751 	DM9000_iow(DM9000_EPAR, DM9000_PHY | reg);
752 
753 	/* Fill the written data into REG_0D & REG_0E */
754 	DM9000_iow(DM9000_EPDRL, (value & 0xff));
755 	DM9000_iow(DM9000_EPDRH, ((value >> 8) & 0xff));
756 	DM9000_iow(DM9000_EPCR, 0xa);	/* Issue phyxcer write command */
757 	udelay(500);			/* Wait write complete */
758 	DM9000_iow(DM9000_EPCR, 0x0);	/* Clear phyxcer write command */
759 	DM9000_DBG("phy_write(reg:0x%x, value:0x%x)\n", reg, value);
760 }
761