xref: /openbmc/u-boot/drivers/net/armada100_fec.c (revision bfc325ed)
1 /*
2  * (C) Copyright 2011
3  * eInfochips Ltd. <www.einfochips.com>
4  * Written-by: Ajay Bhargav <ajay.bhargav@einfochips.com>
5  *
6  * (C) Copyright 2010
7  * Marvell Semiconductor <www.marvell.com>
8  * Contributor: Mahavir Jain <mjain@marvell.com>
9  *
10  * See file CREDITS for list of people who contributed to this
11  * project.
12  *
13  * This program is free software; you can redistribute it and/or
14  * modify it under the terms of the GNU General Public License as
15  * published by the Free Software Foundation; either version 2 of
16  * the License, or (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
26  * MA 02110-1301 USA
27  */
28 
29 #include <common.h>
30 #include <net.h>
31 #include <malloc.h>
32 #include <miiphy.h>
33 #include <netdev.h>
34 #include <asm/types.h>
35 #include <asm/byteorder.h>
36 #include <linux/err.h>
37 #include <linux/mii.h>
38 #include <asm/io.h>
39 #include <asm/arch/armada100.h>
40 #include "armada100_fec.h"
41 
42 #define  PHY_ADR_REQ     0xFF	/* Magic number to read/write PHY address */
43 
44 #ifdef DEBUG
45 static int eth_dump_regs(struct eth_device *dev)
46 {
47 	struct armdfec_device *darmdfec = to_darmdfec(dev);
48 	struct armdfec_reg *regs = darmdfec->regs;
49 	unsigned int i = 0;
50 
51 	printf("\noffset: phy_adr, value: 0x%x\n", readl(&regs->phyadr));
52 	printf("offset: smi, value: 0x%x\n", readl(&regs->smi));
53 	for (i = 0x400; i <= 0x4e4; i += 4)
54 		printf("offset: 0x%x, value: 0x%x\n",
55 			i, readl(ARMD1_FEC_BASE + i));
56 	return 0;
57 }
58 #endif
59 
60 static int armdfec_phy_timeout(u32 *reg, u32 flag, int cond)
61 {
62 	u32 timeout = PHY_WAIT_ITERATIONS;
63 	u32 reg_val;
64 
65 	while (--timeout) {
66 		reg_val = readl(reg);
67 		if (cond && (reg_val & flag))
68 			break;
69 		else if (!cond && !(reg_val & flag))
70 			break;
71 		udelay(PHY_WAIT_MICRO_SECONDS);
72 	}
73 	return !timeout;
74 }
75 
76 static int smi_reg_read(const char *devname, u8 phy_addr, u8 phy_reg,
77 			u16 *value)
78 {
79 	struct eth_device *dev = eth_get_dev_by_name(devname);
80 	struct armdfec_device *darmdfec = to_darmdfec(dev);
81 	struct armdfec_reg *regs = darmdfec->regs;
82 	u32 val;
83 
84 	if (phy_addr == PHY_ADR_REQ && phy_reg == PHY_ADR_REQ) {
85 		val = readl(&regs->phyadr);
86 		*value = val & 0x1f;
87 		return 0;
88 	}
89 
90 	/* check parameters */
91 	if (phy_addr > PHY_MASK) {
92 		printf("ARMD100 FEC: (%s) Invalid phy address: 0x%X\n",
93 				__func__, phy_addr);
94 		return -EINVAL;
95 	}
96 	if (phy_reg > PHY_MASK) {
97 		printf("ARMD100 FEC: (%s) Invalid register offset: 0x%X\n",
98 				__func__, phy_reg);
99 		return -EINVAL;
100 	}
101 
102 	/* wait for the SMI register to become available */
103 	if (armdfec_phy_timeout(&regs->smi, SMI_BUSY, FALSE)) {
104 		printf("ARMD100 FEC: (%s) PHY busy timeout\n",	__func__);
105 		return -1;
106 	}
107 
108 	writel((phy_addr << 16) | (phy_reg << 21) | SMI_OP_R, &regs->smi);
109 
110 	/* now wait for the data to be valid */
111 	if (armdfec_phy_timeout(&regs->smi, SMI_R_VALID, TRUE)) {
112 		val = readl(&regs->smi);
113 		printf("ARMD100 FEC: (%s) PHY Read timeout, val=0x%x\n",
114 				__func__, val);
115 		return -1;
116 	}
117 	val = readl(&regs->smi);
118 	*value = val & 0xffff;
119 
120 	return 0;
121 }
122 
123 static int smi_reg_write(const char *devname,
124 	 u8 phy_addr, u8 phy_reg, u16 value)
125 {
126 	struct eth_device *dev = eth_get_dev_by_name(devname);
127 	struct armdfec_device *darmdfec = to_darmdfec(dev);
128 	struct armdfec_reg *regs = darmdfec->regs;
129 
130 	if (phy_addr == PHY_ADR_REQ && phy_reg == PHY_ADR_REQ) {
131 		clrsetbits_le32(&regs->phyadr, 0x1f, value & 0x1f);
132 		return 0;
133 	}
134 
135 	/* check parameters */
136 	if (phy_addr > PHY_MASK) {
137 		printf("ARMD100 FEC: (%s) Invalid phy address\n", __func__);
138 		return -EINVAL;
139 	}
140 	if (phy_reg > PHY_MASK) {
141 		printf("ARMD100 FEC: (%s) Invalid register offset\n", __func__);
142 		return -EINVAL;
143 	}
144 
145 	/* wait for the SMI register to become available */
146 	if (armdfec_phy_timeout(&regs->smi, SMI_BUSY, FALSE)) {
147 		printf("ARMD100 FEC: (%s) PHY busy timeout\n",	__func__);
148 		return -1;
149 	}
150 
151 	writel((phy_addr << 16) | (phy_reg << 21) | SMI_OP_W | (value & 0xffff),
152 			&regs->smi);
153 	return 0;
154 }
155 
156 /*
157  * Abort any transmit and receive operations and put DMA
158  * in idle state. AT and AR bits are cleared upon entering
159  * in IDLE state. So poll those bits to verify operation.
160  */
161 static void abortdma(struct eth_device *dev)
162 {
163 	struct armdfec_device *darmdfec = to_darmdfec(dev);
164 	struct armdfec_reg *regs = darmdfec->regs;
165 	int delay;
166 	int maxretries = 40;
167 	u32 tmp;
168 
169 	while (--maxretries) {
170 		writel(SDMA_CMD_AR | SDMA_CMD_AT, &regs->sdma_cmd);
171 		udelay(100);
172 
173 		delay = 10;
174 		while (--delay) {
175 			tmp = readl(&regs->sdma_cmd);
176 			if (!(tmp & (SDMA_CMD_AR | SDMA_CMD_AT)))
177 				break;
178 			udelay(10);
179 		}
180 		if (delay)
181 			break;
182 	}
183 
184 	if (!maxretries)
185 		printf("ARMD100 FEC: (%s) DMA Stuck\n", __func__);
186 }
187 
188 static inline u32 nibble_swapping_32_bit(u32 x)
189 {
190 	return ((x & 0xf0f0f0f0) >> 4) | ((x & 0x0f0f0f0f) << 4);
191 }
192 
193 static inline u32 nibble_swapping_16_bit(u32 x)
194 {
195 	return ((x & 0x0000f0f0) >> 4) | ((x & 0x00000f0f) << 4);
196 }
197 
198 static inline u32 flip_4_bits(u32 x)
199 {
200 	return ((x & 0x01) << 3) | ((x & 0x002) << 1)
201 		| ((x & 0x04) >> 1) | ((x & 0x008) >> 3);
202 }
203 
204 /*
205  * This function will calculate the hash function of the address.
206  * depends on the hash mode and hash size.
207  * Inputs
208  * mach             - the 2 most significant bytes of the MAC address.
209  * macl             - the 4 least significant bytes of the MAC address.
210  * Outputs
211  * return the calculated entry.
212  */
213 static u32 hash_function(u32 mach, u32 macl)
214 {
215 	u32 hashresult;
216 	u32 addrh;
217 	u32 addrl;
218 	u32 addr0;
219 	u32 addr1;
220 	u32 addr2;
221 	u32 addr3;
222 	u32 addrhswapped;
223 	u32 addrlswapped;
224 
225 	addrh = nibble_swapping_16_bit(mach);
226 	addrl = nibble_swapping_32_bit(macl);
227 
228 	addrhswapped = flip_4_bits(addrh & 0xf)
229 		+ ((flip_4_bits((addrh >> 4) & 0xf)) << 4)
230 		+ ((flip_4_bits((addrh >> 8) & 0xf)) << 8)
231 		+ ((flip_4_bits((addrh >> 12) & 0xf)) << 12);
232 
233 	addrlswapped = flip_4_bits(addrl & 0xf)
234 		+ ((flip_4_bits((addrl >> 4) & 0xf)) << 4)
235 		+ ((flip_4_bits((addrl >> 8) & 0xf)) << 8)
236 		+ ((flip_4_bits((addrl >> 12) & 0xf)) << 12)
237 		+ ((flip_4_bits((addrl >> 16) & 0xf)) << 16)
238 		+ ((flip_4_bits((addrl >> 20) & 0xf)) << 20)
239 		+ ((flip_4_bits((addrl >> 24) & 0xf)) << 24)
240 		+ ((flip_4_bits((addrl >> 28) & 0xf)) << 28);
241 
242 	addrh = addrhswapped;
243 	addrl = addrlswapped;
244 
245 	addr0 = (addrl >> 2) & 0x03f;
246 	addr1 = (addrl & 0x003) | (((addrl >> 8) & 0x7f) << 2);
247 	addr2 = (addrl >> 15) & 0x1ff;
248 	addr3 = ((addrl >> 24) & 0x0ff) | ((addrh & 1) << 8);
249 
250 	hashresult = (addr0 << 9) | (addr1 ^ addr2 ^ addr3);
251 	hashresult = hashresult & 0x07ff;
252 	return hashresult;
253 }
254 
255 /*
256  * This function will add an entry to the address table.
257  * depends on the hash mode and hash size that was initialized.
258  * Inputs
259  * mach - the 2 most significant bytes of the MAC address.
260  * macl - the 4 least significant bytes of the MAC address.
261  * skip - if 1, skip this address.
262  * rd   - the RD field in the address table.
263  * Outputs
264  * address table entry is added.
265  * 0 if success.
266  * -ENOSPC if table full
267  */
268 static int add_del_hash_entry(struct armdfec_device *darmdfec, u32 mach,
269 			      u32 macl, u32 rd, u32 skip, int del)
270 {
271 	struct addr_table_entry_t *entry, *start;
272 	u32 newhi;
273 	u32 newlo;
274 	u32 i;
275 
276 	newlo = (((mach >> 4) & 0xf) << 15)
277 		| (((mach >> 0) & 0xf) << 11)
278 		| (((mach >> 12) & 0xf) << 7)
279 		| (((mach >> 8) & 0xf) << 3)
280 		| (((macl >> 20) & 0x1) << 31)
281 		| (((macl >> 16) & 0xf) << 27)
282 		| (((macl >> 28) & 0xf) << 23)
283 		| (((macl >> 24) & 0xf) << 19)
284 		| (skip << HTESKIP) | (rd << HTERDBIT)
285 		| HTEVALID;
286 
287 	newhi = (((macl >> 4) & 0xf) << 15)
288 		| (((macl >> 0) & 0xf) << 11)
289 		| (((macl >> 12) & 0xf) << 7)
290 		| (((macl >> 8) & 0xf) << 3)
291 		| (((macl >> 21) & 0x7) << 0);
292 
293 	/*
294 	 * Pick the appropriate table, start scanning for free/reusable
295 	 * entries at the index obtained by hashing the specified MAC address
296 	 */
297 	start = (struct addr_table_entry_t *)(darmdfec->htpr);
298 	entry = start + hash_function(mach, macl);
299 	for (i = 0; i < HOP_NUMBER; i++) {
300 		if (!(entry->lo & HTEVALID)) {
301 			break;
302 		} else {
303 			/* if same address put in same position */
304 			if (((entry->lo & 0xfffffff8) == (newlo & 0xfffffff8))
305 					&& (entry->hi == newhi))
306 				break;
307 		}
308 		if (entry == start + 0x7ff)
309 			entry = start;
310 		else
311 			entry++;
312 	}
313 
314 	if (((entry->lo & 0xfffffff8) != (newlo & 0xfffffff8)) &&
315 		(entry->hi != newhi) && del)
316 		return 0;
317 
318 	if (i == HOP_NUMBER) {
319 		if (!del) {
320 			printf("ARMD100 FEC: (%s) table section is full\n",
321 					__func__);
322 			return -ENOSPC;
323 		} else {
324 			return 0;
325 		}
326 	}
327 
328 	/*
329 	 * Update the selected entry
330 	 */
331 	if (del) {
332 		entry->hi = 0;
333 		entry->lo = 0;
334 	} else {
335 		entry->hi = newhi;
336 		entry->lo = newlo;
337 	}
338 
339 	return 0;
340 }
341 
342 /*
343  *  Create an addressTable entry from MAC address info
344  *  found in the specifed net_device struct
345  *
346  *  Input : pointer to ethernet interface network device structure
347  *  Output : N/A
348  */
349 static void update_hash_table_mac_address(struct armdfec_device *darmdfec,
350 					  u8 *oaddr, u8 *addr)
351 {
352 	u32 mach;
353 	u32 macl;
354 
355 	/* Delete old entry */
356 	if (oaddr) {
357 		mach = (oaddr[0] << 8) | oaddr[1];
358 		macl = (oaddr[2] << 24) | (oaddr[3] << 16) |
359 			(oaddr[4] << 8) | oaddr[5];
360 		add_del_hash_entry(darmdfec, mach, macl, 1, 0, HASH_DELETE);
361 	}
362 
363 	/* Add new entry */
364 	mach = (addr[0] << 8) | addr[1];
365 	macl = (addr[2] << 24) | (addr[3] << 16) | (addr[4] << 8) | addr[5];
366 	add_del_hash_entry(darmdfec, mach, macl, 1, 0, HASH_ADD);
367 }
368 
369 /* Address Table Initialization */
370 static void init_hashtable(struct eth_device *dev)
371 {
372 	struct armdfec_device *darmdfec = to_darmdfec(dev);
373 	struct armdfec_reg *regs = darmdfec->regs;
374 	memset(darmdfec->htpr, 0, HASH_ADDR_TABLE_SIZE);
375 	writel((u32)darmdfec->htpr, &regs->htpr);
376 }
377 
378 /*
379  * This detects PHY chip from address 0-31 by reading PHY status
380  * registers. PHY chip can be connected at any of this address.
381  */
382 static int ethernet_phy_detect(struct eth_device *dev)
383 {
384 	u32 val;
385 	u16 tmp, mii_status;
386 	u8 addr;
387 
388 	for (addr = 0; addr < 32; addr++) {
389 		if (miiphy_read(dev->name, addr, MII_BMSR, &mii_status)	!= 0)
390 			/* try next phy */
391 			continue;
392 
393 		/* invalid MII status. More validation required here... */
394 		if (mii_status == 0 || mii_status == 0xffff)
395 			/* try next phy */
396 			continue;
397 
398 		if (miiphy_read(dev->name, addr, MII_PHYSID1, &tmp) != 0)
399 			/* try next phy */
400 			continue;
401 
402 		val = tmp << 16;
403 		if (miiphy_read(dev->name, addr, MII_PHYSID2, &tmp) != 0)
404 			/* try next phy */
405 			continue;
406 
407 		val |= tmp;
408 
409 		if ((val & 0xfffffff0) != 0)
410 			return addr;
411 	}
412 	return -1;
413 }
414 
415 static void armdfec_init_rx_desc_ring(struct armdfec_device *darmdfec)
416 {
417 	struct rx_desc *p_rx_desc;
418 	int i;
419 
420 	/* initialize the Rx descriptors ring */
421 	p_rx_desc = darmdfec->p_rxdesc;
422 	for (i = 0; i < RINGSZ; i++) {
423 		p_rx_desc->cmd_sts = BUF_OWNED_BY_DMA | RX_EN_INT;
424 		p_rx_desc->buf_size = PKTSIZE_ALIGN;
425 		p_rx_desc->byte_cnt = 0;
426 		p_rx_desc->buf_ptr = darmdfec->p_rxbuf + i * PKTSIZE_ALIGN;
427 		if (i == (RINGSZ - 1)) {
428 			p_rx_desc->nxtdesc_p = darmdfec->p_rxdesc;
429 		} else {
430 			p_rx_desc->nxtdesc_p = (struct rx_desc *)
431 			    ((u32)p_rx_desc + ARMDFEC_RXQ_DESC_ALIGNED_SIZE);
432 			p_rx_desc = p_rx_desc->nxtdesc_p;
433 		}
434 	}
435 	darmdfec->p_rxdesc_curr = darmdfec->p_rxdesc;
436 }
437 
438 static int armdfec_init(struct eth_device *dev, bd_t *bd)
439 {
440 	struct armdfec_device *darmdfec = to_darmdfec(dev);
441 	struct armdfec_reg *regs = darmdfec->regs;
442 	int phy_adr;
443 	u32 temp;
444 
445 	armdfec_init_rx_desc_ring(darmdfec);
446 
447 	/* Disable interrupts */
448 	writel(0, &regs->im);
449 	writel(0, &regs->ic);
450 	/* Write to ICR to clear interrupts. */
451 	writel(0, &regs->iwc);
452 
453 	/*
454 	 * Abort any transmit and receive operations and put DMA
455 	 * in idle state.
456 	 */
457 	abortdma(dev);
458 
459 	/* Initialize address hash table */
460 	init_hashtable(dev);
461 
462 	/* SDMA configuration */
463 	writel(SDCR_BSZ8 |	/* Burst size = 32 bytes */
464 		SDCR_RIFB |	/* Rx interrupt on frame */
465 		SDCR_BLMT |	/* Little endian transmit */
466 		SDCR_BLMR |	/* Little endian receive */
467 		SDCR_RC_MAX_RETRANS,	/* Max retransmit count */
468 		&regs->sdma_conf);
469 	/* Port Configuration */
470 	writel(PCR_HS, &regs->pconf);	/* Hash size is 1/2kb */
471 
472 	/* Set extended port configuration */
473 	writel(PCXR_2BSM |		/* Two byte suffix aligns IP hdr */
474 		PCXR_DSCP_EN |		/* Enable DSCP in IP */
475 		PCXR_MFL_1536 |		/* Set MTU = 1536 */
476 		PCXR_FLP |		/* do not force link pass */
477 		PCXR_TX_HIGH_PRI,	/* Transmit - high priority queue */
478 		&regs->pconf_ext);
479 
480 	update_hash_table_mac_address(darmdfec, NULL, dev->enetaddr);
481 
482 	/* Update TX and RX queue descriptor register */
483 	temp = (u32)&regs->txcdp[TXQ];
484 	writel((u32)darmdfec->p_txdesc, temp);
485 	temp = (u32)&regs->rxfdp[RXQ];
486 	writel((u32)darmdfec->p_rxdesc, temp);
487 	temp = (u32)&regs->rxcdp[RXQ];
488 	writel((u32)darmdfec->p_rxdesc_curr, temp);
489 
490 	/* Enable Interrupts */
491 	writel(ALL_INTS, &regs->im);
492 
493 	/* Enable Ethernet Port */
494 	setbits_le32(&regs->pconf, PCR_EN);
495 
496 	/* Enable RX DMA engine */
497 	setbits_le32(&regs->sdma_cmd, SDMA_CMD_ERD);
498 
499 #ifdef DEBUG
500 	eth_dump_regs(dev);
501 #endif
502 
503 #if (defined(CONFIG_MII) || defined(CONFIG_CMD_MII))
504 
505 #if defined(CONFIG_PHY_BASE_ADR)
506 	miiphy_write(dev->name, PHY_ADR_REQ, PHY_ADR_REQ, CONFIG_PHY_BASE_ADR);
507 #else
508 	/* Search phy address from range 0-31 */
509 	phy_adr = ethernet_phy_detect(dev);
510 	if (phy_adr < 0) {
511 		printf("ARMD100 FEC: PHY not detected at address range 0-31\n");
512 		return -1;
513 	} else {
514 		debug("ARMD100 FEC: PHY detected at addr %d\n", phy_adr);
515 		miiphy_write(dev->name, PHY_ADR_REQ, PHY_ADR_REQ, phy_adr);
516 	}
517 #endif
518 
519 #if defined(CONFIG_SYS_FAULT_ECHO_LINK_DOWN)
520 	/* Wait up to 5s for the link status */
521 	for (i = 0; i < 5; i++) {
522 		u16 phy_adr;
523 
524 		miiphy_read(dev->name, 0xFF, 0xFF, &phy_adr);
525 		/* Return if we get link up */
526 		if (miiphy_link(dev->name, phy_adr))
527 			return 0;
528 		udelay(1000000);
529 	}
530 
531 	printf("ARMD100 FEC: No link on %s\n", dev->name);
532 	return -1;
533 #endif
534 #endif
535 	return 0;
536 }
537 
538 static void armdfec_halt(struct eth_device *dev)
539 {
540 	struct armdfec_device *darmdfec = to_darmdfec(dev);
541 	struct armdfec_reg *regs = darmdfec->regs;
542 
543 	/* Stop RX DMA */
544 	clrbits_le32(&regs->sdma_cmd, SDMA_CMD_ERD);
545 
546 	/*
547 	 * Abort any transmit and receive operations and put DMA
548 	 * in idle state.
549 	 */
550 	abortdma(dev);
551 
552 	/* Disable interrupts */
553 	writel(0, &regs->im);
554 	writel(0, &regs->ic);
555 	writel(0, &regs->iwc);
556 
557 	/* Disable Port */
558 	clrbits_le32(&regs->pconf, PCR_EN);
559 }
560 
561 static int armdfec_send(struct eth_device *dev, void *dataptr, int datasize)
562 {
563 	struct armdfec_device *darmdfec = to_darmdfec(dev);
564 	struct armdfec_reg *regs = darmdfec->regs;
565 	struct tx_desc *p_txdesc = darmdfec->p_txdesc;
566 	void *p = (void *)dataptr;
567 	int retry = PHY_WAIT_ITERATIONS * PHY_WAIT_MICRO_SECONDS;
568 	u32 cmd_sts;
569 
570 	/* Copy buffer if it's misaligned */
571 	if ((u32)dataptr & 0x07) {
572 		if (datasize > PKTSIZE_ALIGN) {
573 			printf("ARMD100 FEC: Non-aligned data too large (%d)\n",
574 					datasize);
575 			return -1;
576 		}
577 		memcpy(darmdfec->p_aligned_txbuf, p, datasize);
578 		p = darmdfec->p_aligned_txbuf;
579 	}
580 
581 	p_txdesc->cmd_sts = TX_ZERO_PADDING | TX_GEN_CRC;
582 	p_txdesc->cmd_sts |= TX_FIRST_DESC | TX_LAST_DESC;
583 	p_txdesc->cmd_sts |= BUF_OWNED_BY_DMA;
584 	p_txdesc->cmd_sts |= TX_EN_INT;
585 	p_txdesc->buf_ptr = p;
586 	p_txdesc->byte_cnt = datasize;
587 
588 	/* Apply send command using high priority TX queue */
589 	writel((u32)p_txdesc, &regs->txcdp[TXQ]);
590 	writel(SDMA_CMD_TXDL | SDMA_CMD_TXDH | SDMA_CMD_ERD, &regs->sdma_cmd);
591 
592 	/*
593 	 * wait for packet xmit completion
594 	 */
595 	cmd_sts = readl(&p_txdesc->cmd_sts);
596 	while (cmd_sts & BUF_OWNED_BY_DMA) {
597 		/* return fail if error is detected */
598 		if ((cmd_sts & (TX_ERROR | TX_LAST_DESC)) ==
599 			(TX_ERROR | TX_LAST_DESC)) {
600 			printf("ARMD100 FEC: (%s) in xmit packet\n", __func__);
601 			return -1;
602 		}
603 		cmd_sts = readl(&p_txdesc->cmd_sts);
604 		if (!(retry--)) {
605 			printf("ARMD100 FEC: (%s) xmit packet timeout!\n",
606 					__func__);
607 			return -1;
608 		}
609 	}
610 
611 	return 0;
612 }
613 
614 static int armdfec_recv(struct eth_device *dev)
615 {
616 	struct armdfec_device *darmdfec = to_darmdfec(dev);
617 	struct rx_desc *p_rxdesc_curr = darmdfec->p_rxdesc_curr;
618 	u32 cmd_sts;
619 	u32 timeout = 0;
620 	u32 temp;
621 
622 	/* wait untill rx packet available or timeout */
623 	do {
624 		if (timeout < PHY_WAIT_ITERATIONS * PHY_WAIT_MICRO_SECONDS) {
625 			timeout++;
626 		} else {
627 			debug("ARMD100 FEC: %s time out...\n", __func__);
628 			return -1;
629 		}
630 	} while (readl(&p_rxdesc_curr->cmd_sts) & BUF_OWNED_BY_DMA);
631 
632 	if (p_rxdesc_curr->byte_cnt != 0) {
633 		debug("ARMD100 FEC: %s: Received %d byte Packet @ 0x%x"
634 				"(cmd_sts= %08x)\n", __func__,
635 				(u32)p_rxdesc_curr->byte_cnt,
636 				(u32)p_rxdesc_curr->buf_ptr,
637 				(u32)p_rxdesc_curr->cmd_sts);
638 	}
639 
640 	/*
641 	 * In case received a packet without first/last bits on
642 	 * OR the error summary bit is on,
643 	 * the packets needs to be dropeed.
644 	 */
645 	cmd_sts = readl(&p_rxdesc_curr->cmd_sts);
646 
647 	if ((cmd_sts & (RX_FIRST_DESC | RX_LAST_DESC)) !=
648 			(RX_FIRST_DESC | RX_LAST_DESC)) {
649 		printf("ARMD100 FEC: (%s) Dropping packet spread on"
650 			" multiple descriptors\n", __func__);
651 	} else if (cmd_sts & RX_ERROR) {
652 		printf("ARMD100 FEC: (%s) Dropping packet with errors\n",
653 				__func__);
654 	} else {
655 		/* !!! call higher layer processing */
656 		debug("ARMD100 FEC: (%s) Sending Received packet to"
657 			" upper layer (NetReceive)\n", __func__);
658 
659 		/*
660 		 * let the upper layer handle the packet, subtract offset
661 		 * as two dummy bytes are added in received buffer see
662 		 * PORT_CONFIG_EXT register bit TWO_Byte_Stuff_Mode bit.
663 		 */
664 		NetReceive((p_rxdesc_curr->buf_ptr + RX_BUF_OFFSET),
665 			   (int)(p_rxdesc_curr->byte_cnt - RX_BUF_OFFSET));
666 	}
667 	/*
668 	 * free these descriptors and point next in the ring
669 	 */
670 	p_rxdesc_curr->cmd_sts = BUF_OWNED_BY_DMA | RX_EN_INT;
671 	p_rxdesc_curr->buf_size = PKTSIZE_ALIGN;
672 	p_rxdesc_curr->byte_cnt = 0;
673 
674 	temp = (u32)&darmdfec->p_rxdesc_curr;
675 	writel((u32)p_rxdesc_curr->nxtdesc_p, temp);
676 
677 	return 0;
678 }
679 
680 int armada100_fec_register(unsigned long base_addr)
681 {
682 	struct armdfec_device *darmdfec;
683 	struct eth_device *dev;
684 
685 	darmdfec = malloc(sizeof(struct armdfec_device));
686 	if (!darmdfec)
687 		goto error;
688 
689 	memset(darmdfec, 0, sizeof(struct armdfec_device));
690 
691 	darmdfec->htpr = memalign(8, HASH_ADDR_TABLE_SIZE);
692 	if (!darmdfec->htpr)
693 		goto error1;
694 
695 	darmdfec->p_rxdesc = memalign(PKTALIGN,
696 			ARMDFEC_RXQ_DESC_ALIGNED_SIZE * RINGSZ + 1);
697 
698 	if (!darmdfec->p_rxdesc)
699 		goto error1;
700 
701 	darmdfec->p_rxbuf = memalign(PKTALIGN, RINGSZ * PKTSIZE_ALIGN + 1);
702 	if (!darmdfec->p_rxbuf)
703 		goto error1;
704 
705 	darmdfec->p_aligned_txbuf = memalign(8, PKTSIZE_ALIGN);
706 	if (!darmdfec->p_aligned_txbuf)
707 		goto error1;
708 
709 	darmdfec->p_txdesc = memalign(PKTALIGN, sizeof(struct tx_desc) + 1);
710 	if (!darmdfec->p_txdesc)
711 		goto error1;
712 
713 	dev = &darmdfec->dev;
714 	/* Assign ARMADA100 Fast Ethernet Controller Base Address */
715 	darmdfec->regs = (void *)base_addr;
716 
717 	/* must be less than sizeof(dev->name) */
718 	strcpy(dev->name, "armd-fec0");
719 
720 	dev->init = armdfec_init;
721 	dev->halt = armdfec_halt;
722 	dev->send = armdfec_send;
723 	dev->recv = armdfec_recv;
724 
725 	eth_register(dev);
726 
727 #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
728 	miiphy_register(dev->name, smi_reg_read, smi_reg_write);
729 #endif
730 	return 0;
731 
732 error1:
733 	free(darmdfec->p_aligned_txbuf);
734 	free(darmdfec->p_rxbuf);
735 	free(darmdfec->p_rxdesc);
736 	free(darmdfec->htpr);
737 error:
738 	free(darmdfec);
739 	printf("AMD100 FEC: (%s) Failed to allocate memory\n", __func__);
740 	return -1;
741 }
742