xref: /openbmc/u-boot/drivers/net/fec_mxc.c (revision 25ceb277)
1 /*
2  * (C) Copyright 2009 Ilya Yanok, Emcraft Systems Ltd <yanok@emcraft.com>
3  * (C) Copyright 2008,2009 Eric Jarrige <eric.jarrige@armadeus.org>
4  * (C) Copyright 2008 Armadeus Systems nc
5  * (C) Copyright 2007 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
6  * (C) Copyright 2007 Pengutronix, Juergen Beisert <j.beisert@pengutronix.de>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 #include <common.h>
25 #include <malloc.h>
26 #include <net.h>
27 #include <miiphy.h>
28 #include "fec_mxc.h"
29 
30 #include <asm/arch/clock.h>
31 #include <asm/arch/imx-regs.h>
32 #include <asm/io.h>
33 #include <asm/errno.h>
34 
35 DECLARE_GLOBAL_DATA_PTR;
36 
37 #ifndef CONFIG_MII
38 #error "CONFIG_MII has to be defined!"
39 #endif
40 
41 #ifndef	CONFIG_FEC_XCV_TYPE
42 #define	CONFIG_FEC_XCV_TYPE	MII100
43 #endif
44 
45 #undef DEBUG
46 
47 struct nbuf {
48 	uint8_t data[1500];	/**< actual data */
49 	int length;		/**< actual length */
50 	int used;		/**< buffer in use or not */
51 	uint8_t head[16];	/**< MAC header(6 + 6 + 2) + 2(aligned) */
52 };
53 
54 /*
55  * MII-interface related functions
56  */
57 static int fec_miiphy_read(const char *dev, uint8_t phyAddr, uint8_t regAddr,
58 		uint16_t *retVal)
59 {
60 	struct eth_device *edev = eth_get_dev_by_name(dev);
61 	struct fec_priv *fec = (struct fec_priv *)edev->priv;
62 	struct ethernet_regs *eth = fec->eth;
63 
64 	uint32_t reg;		/* convenient holder for the PHY register */
65 	uint32_t phy;		/* convenient holder for the PHY */
66 	uint32_t start;
67 
68 	/*
69 	 * reading from any PHY's register is done by properly
70 	 * programming the FEC's MII data register.
71 	 */
72 	writel(FEC_IEVENT_MII, &eth->ievent);
73 	reg = regAddr << FEC_MII_DATA_RA_SHIFT;
74 	phy = phyAddr << FEC_MII_DATA_PA_SHIFT;
75 
76 	writel(FEC_MII_DATA_ST | FEC_MII_DATA_OP_RD | FEC_MII_DATA_TA |
77 			phy | reg, &eth->mii_data);
78 
79 	/*
80 	 * wait for the related interrupt
81 	 */
82 	start = get_timer(0);
83 	while (!(readl(&eth->ievent) & FEC_IEVENT_MII)) {
84 		if (get_timer(start) > (CONFIG_SYS_HZ / 1000)) {
85 			printf("Read MDIO failed...\n");
86 			return -1;
87 		}
88 	}
89 
90 	/*
91 	 * clear mii interrupt bit
92 	 */
93 	writel(FEC_IEVENT_MII, &eth->ievent);
94 
95 	/*
96 	 * it's now safe to read the PHY's register
97 	 */
98 	*retVal = readl(&eth->mii_data);
99 	debug("fec_miiphy_read: phy: %02x reg:%02x val:%#x\n", phyAddr,
100 			regAddr, *retVal);
101 	return 0;
102 }
103 
104 static void fec_mii_setspeed(struct fec_priv *fec)
105 {
106 	/*
107 	 * Set MII_SPEED = (1/(mii_speed * 2)) * System Clock
108 	 * and do not drop the Preamble.
109 	 */
110 	writel((((imx_get_fecclk() / 1000000) + 2) / 5) << 1,
111 			&fec->eth->mii_speed);
112 	debug("fec_init: mii_speed %#lx\n",
113 			readl(&fec->eth->mii_speed));
114 }
115 static int fec_miiphy_write(const char *dev, uint8_t phyAddr, uint8_t regAddr,
116 		uint16_t data)
117 {
118 	struct eth_device *edev = eth_get_dev_by_name(dev);
119 	struct fec_priv *fec = (struct fec_priv *)edev->priv;
120 	struct ethernet_regs *eth = fec->eth;
121 
122 	uint32_t reg;		/* convenient holder for the PHY register */
123 	uint32_t phy;		/* convenient holder for the PHY */
124 	uint32_t start;
125 
126 	reg = regAddr << FEC_MII_DATA_RA_SHIFT;
127 	phy = phyAddr << FEC_MII_DATA_PA_SHIFT;
128 
129 	writel(FEC_MII_DATA_ST | FEC_MII_DATA_OP_WR |
130 		FEC_MII_DATA_TA | phy | reg | data, &eth->mii_data);
131 
132 	/*
133 	 * wait for the MII interrupt
134 	 */
135 	start = get_timer(0);
136 	while (!(readl(&eth->ievent) & FEC_IEVENT_MII)) {
137 		if (get_timer(start) > (CONFIG_SYS_HZ / 1000)) {
138 			printf("Write MDIO failed...\n");
139 			return -1;
140 		}
141 	}
142 
143 	/*
144 	 * clear MII interrupt bit
145 	 */
146 	writel(FEC_IEVENT_MII, &eth->ievent);
147 	debug("fec_miiphy_write: phy: %02x reg:%02x val:%#x\n", phyAddr,
148 			regAddr, data);
149 
150 	return 0;
151 }
152 
153 static int miiphy_restart_aneg(struct eth_device *dev)
154 {
155 	struct fec_priv *fec = (struct fec_priv *)dev->priv;
156 	int ret = 0;
157 
158 	/*
159 	 * Wake up from sleep if necessary
160 	 * Reset PHY, then delay 300ns
161 	 */
162 #ifdef CONFIG_MX27
163 	miiphy_write(dev->name, fec->phy_id, MII_DCOUNTER, 0x00FF);
164 #endif
165 	miiphy_write(dev->name, fec->phy_id, MII_BMCR,
166 			BMCR_RESET);
167 	udelay(1000);
168 
169 	/*
170 	 * Set the auto-negotiation advertisement register bits
171 	 */
172 	miiphy_write(dev->name, fec->phy_id, MII_ADVERTISE,
173 			LPA_100FULL | LPA_100HALF | LPA_10FULL |
174 			LPA_10HALF | PHY_ANLPAR_PSB_802_3);
175 	miiphy_write(dev->name, fec->phy_id, MII_BMCR,
176 			BMCR_ANENABLE | BMCR_ANRESTART);
177 
178 	if (fec->mii_postcall)
179 		ret = fec->mii_postcall(fec->phy_id);
180 
181 	return ret;
182 }
183 
184 static int miiphy_wait_aneg(struct eth_device *dev)
185 {
186 	uint32_t start;
187 	uint16_t status;
188 	struct fec_priv *fec = (struct fec_priv *)dev->priv;
189 
190 	/*
191 	 * Wait for AN completion
192 	 */
193 	start = get_timer(0);
194 	do {
195 		if (get_timer(start) > (CONFIG_SYS_HZ * 5)) {
196 			printf("%s: Autonegotiation timeout\n", dev->name);
197 			return -1;
198 		}
199 
200 		if (miiphy_read(dev->name, fec->phy_id,
201 					MII_BMSR, &status)) {
202 			printf("%s: Autonegotiation failed. status: 0x%04x\n",
203 					dev->name, status);
204 			return -1;
205 		}
206 	} while (!(status & BMSR_LSTATUS));
207 
208 	return 0;
209 }
210 static int fec_rx_task_enable(struct fec_priv *fec)
211 {
212 	writel(1 << 24, &fec->eth->r_des_active);
213 	return 0;
214 }
215 
216 static int fec_rx_task_disable(struct fec_priv *fec)
217 {
218 	return 0;
219 }
220 
221 static int fec_tx_task_enable(struct fec_priv *fec)
222 {
223 	writel(1 << 24, &fec->eth->x_des_active);
224 	return 0;
225 }
226 
227 static int fec_tx_task_disable(struct fec_priv *fec)
228 {
229 	return 0;
230 }
231 
232 /**
233  * Initialize receive task's buffer descriptors
234  * @param[in] fec all we know about the device yet
235  * @param[in] count receive buffer count to be allocated
236  * @param[in] size size of each receive buffer
237  * @return 0 on success
238  *
239  * For this task we need additional memory for the data buffers. And each
240  * data buffer requires some alignment. Thy must be aligned to a specific
241  * boundary each (DB_DATA_ALIGNMENT).
242  */
243 static int fec_rbd_init(struct fec_priv *fec, int count, int size)
244 {
245 	int ix;
246 	uint32_t p = 0;
247 
248 	/* reserve data memory and consider alignment */
249 	if (fec->rdb_ptr == NULL)
250 		fec->rdb_ptr = malloc(size * count + DB_DATA_ALIGNMENT);
251 	p = (uint32_t)fec->rdb_ptr;
252 	if (!p) {
253 		puts("fec_mxc: not enough malloc memory\n");
254 		return -ENOMEM;
255 	}
256 	memset((void *)p, 0, size * count + DB_DATA_ALIGNMENT);
257 	p += DB_DATA_ALIGNMENT-1;
258 	p &= ~(DB_DATA_ALIGNMENT-1);
259 
260 	for (ix = 0; ix < count; ix++) {
261 		writel(p, &fec->rbd_base[ix].data_pointer);
262 		p += size;
263 		writew(FEC_RBD_EMPTY, &fec->rbd_base[ix].status);
264 		writew(0, &fec->rbd_base[ix].data_length);
265 	}
266 	/*
267 	 * mark the last RBD to close the ring
268 	 */
269 	writew(FEC_RBD_WRAP | FEC_RBD_EMPTY, &fec->rbd_base[ix - 1].status);
270 	fec->rbd_index = 0;
271 
272 	return 0;
273 }
274 
275 /**
276  * Initialize transmit task's buffer descriptors
277  * @param[in] fec all we know about the device yet
278  *
279  * Transmit buffers are created externally. We only have to init the BDs here.\n
280  * Note: There is a race condition in the hardware. When only one BD is in
281  * use it must be marked with the WRAP bit to use it for every transmitt.
282  * This bit in combination with the READY bit results into double transmit
283  * of each data buffer. It seems the state machine checks READY earlier then
284  * resetting it after the first transfer.
285  * Using two BDs solves this issue.
286  */
287 static void fec_tbd_init(struct fec_priv *fec)
288 {
289 	writew(0x0000, &fec->tbd_base[0].status);
290 	writew(FEC_TBD_WRAP, &fec->tbd_base[1].status);
291 	fec->tbd_index = 0;
292 }
293 
294 /**
295  * Mark the given read buffer descriptor as free
296  * @param[in] last 1 if this is the last buffer descriptor in the chain, else 0
297  * @param[in] pRbd buffer descriptor to mark free again
298  */
299 static void fec_rbd_clean(int last, struct fec_bd *pRbd)
300 {
301 	/*
302 	 * Reset buffer descriptor as empty
303 	 */
304 	if (last)
305 		writew(FEC_RBD_WRAP | FEC_RBD_EMPTY, &pRbd->status);
306 	else
307 		writew(FEC_RBD_EMPTY, &pRbd->status);
308 	/*
309 	 * no data in it
310 	 */
311 	writew(0, &pRbd->data_length);
312 }
313 
314 static int fec_get_hwaddr(struct eth_device *dev, unsigned char *mac)
315 {
316 	imx_get_mac_from_fuse(mac);
317 	return !is_valid_ether_addr(mac);
318 }
319 
320 static int fec_set_hwaddr(struct eth_device *dev)
321 {
322 	uchar *mac = dev->enetaddr;
323 	struct fec_priv *fec = (struct fec_priv *)dev->priv;
324 
325 	writel(0, &fec->eth->iaddr1);
326 	writel(0, &fec->eth->iaddr2);
327 	writel(0, &fec->eth->gaddr1);
328 	writel(0, &fec->eth->gaddr2);
329 
330 	/*
331 	 * Set physical address
332 	 */
333 	writel((mac[0] << 24) + (mac[1] << 16) + (mac[2] << 8) + mac[3],
334 			&fec->eth->paddr1);
335 	writel((mac[4] << 24) + (mac[5] << 16) + 0x8808, &fec->eth->paddr2);
336 
337 	return 0;
338 }
339 
340 /**
341  * Start the FEC engine
342  * @param[in] dev Our device to handle
343  */
344 static int fec_open(struct eth_device *edev)
345 {
346 	struct fec_priv *fec = (struct fec_priv *)edev->priv;
347 
348 	debug("fec_open: fec_open(dev)\n");
349 	/* full-duplex, heartbeat disabled */
350 	writel(1 << 2, &fec->eth->x_cntrl);
351 	fec->rbd_index = 0;
352 
353 	/*
354 	 * Enable FEC-Lite controller
355 	 */
356 	writel(readl(&fec->eth->ecntrl) | FEC_ECNTRL_ETHER_EN,
357 		&fec->eth->ecntrl);
358 #if defined(CONFIG_MX25) || defined(CONFIG_MX53)
359 	udelay(100);
360 	/*
361 	 * setup the MII gasket for RMII mode
362 	 */
363 
364 	/* disable the gasket */
365 	writew(0, &fec->eth->miigsk_enr);
366 
367 	/* wait for the gasket to be disabled */
368 	while (readw(&fec->eth->miigsk_enr) & MIIGSK_ENR_READY)
369 		udelay(2);
370 
371 	/* configure gasket for RMII, 50 MHz, no loopback, and no echo */
372 	writew(MIIGSK_CFGR_IF_MODE_RMII, &fec->eth->miigsk_cfgr);
373 
374 	/* re-enable the gasket */
375 	writew(MIIGSK_ENR_EN, &fec->eth->miigsk_enr);
376 
377 	/* wait until MII gasket is ready */
378 	int max_loops = 10;
379 	while ((readw(&fec->eth->miigsk_enr) & MIIGSK_ENR_READY) == 0) {
380 		if (--max_loops <= 0) {
381 			printf("WAIT for MII Gasket ready timed out\n");
382 			break;
383 		}
384 	}
385 #endif
386 
387 	miiphy_wait_aneg(edev);
388 	miiphy_speed(edev->name, fec->phy_id);
389 	miiphy_duplex(edev->name, fec->phy_id);
390 
391 	/*
392 	 * Enable SmartDMA receive task
393 	 */
394 	fec_rx_task_enable(fec);
395 
396 	udelay(100000);
397 	return 0;
398 }
399 
400 static int fec_init(struct eth_device *dev, bd_t* bd)
401 {
402 	uint32_t base;
403 	struct fec_priv *fec = (struct fec_priv *)dev->priv;
404 	uint32_t mib_ptr = (uint32_t)&fec->eth->rmon_t_drop;
405 	uint32_t rcntrl;
406 	int i;
407 
408 	/* Initialize MAC address */
409 	fec_set_hwaddr(dev);
410 
411 	/*
412 	 * reserve memory for both buffer descriptor chains at once
413 	 * Datasheet forces the startaddress of each chain is 16 byte
414 	 * aligned
415 	 */
416 	if (fec->base_ptr == NULL)
417 		fec->base_ptr = malloc((2 + FEC_RBD_NUM) *
418 				sizeof(struct fec_bd) + DB_ALIGNMENT);
419 	base = (uint32_t)fec->base_ptr;
420 	if (!base) {
421 		puts("fec_mxc: not enough malloc memory\n");
422 		return -ENOMEM;
423 	}
424 	memset((void *)base, 0, (2 + FEC_RBD_NUM) *
425 			sizeof(struct fec_bd) + DB_ALIGNMENT);
426 	base += (DB_ALIGNMENT-1);
427 	base &= ~(DB_ALIGNMENT-1);
428 
429 	fec->rbd_base = (struct fec_bd *)base;
430 
431 	base += FEC_RBD_NUM * sizeof(struct fec_bd);
432 
433 	fec->tbd_base = (struct fec_bd *)base;
434 
435 	/*
436 	 * Set interrupt mask register
437 	 */
438 	writel(0x00000000, &fec->eth->imask);
439 
440 	/*
441 	 * Clear FEC-Lite interrupt event register(IEVENT)
442 	 */
443 	writel(0xffffffff, &fec->eth->ievent);
444 
445 
446 	/*
447 	 * Set FEC-Lite receive control register(R_CNTRL):
448 	 */
449 
450 	/* Start with frame length = 1518, common for all modes. */
451 	rcntrl = PKTSIZE << FEC_RCNTRL_MAX_FL_SHIFT;
452 	if (fec->xcv_type == SEVENWIRE)
453 		rcntrl |= FEC_RCNTRL_FCE;
454 	else if (fec->xcv_type == RMII)
455 		rcntrl |= FEC_RCNTRL_RMII;
456 	else	/* MII mode */
457 		rcntrl |= FEC_RCNTRL_FCE | FEC_RCNTRL_MII_MODE;
458 
459 	writel(rcntrl, &fec->eth->r_cntrl);
460 
461 	if (fec->xcv_type == MII10 || fec->xcv_type == MII100)
462 		fec_mii_setspeed(fec);
463 
464 	/*
465 	 * Set Opcode/Pause Duration Register
466 	 */
467 	writel(0x00010020, &fec->eth->op_pause);	/* FIXME 0xffff0020; */
468 	writel(0x2, &fec->eth->x_wmrk);
469 	/*
470 	 * Set multicast address filter
471 	 */
472 	writel(0x00000000, &fec->eth->gaddr1);
473 	writel(0x00000000, &fec->eth->gaddr2);
474 
475 
476 	/* clear MIB RAM */
477 	for (i = mib_ptr; i <= mib_ptr + 0xfc; i += 4)
478 		writel(0, i);
479 
480 	/* FIFO receive start register */
481 	writel(0x520, &fec->eth->r_fstart);
482 
483 	/* size and address of each buffer */
484 	writel(FEC_MAX_PKT_SIZE, &fec->eth->emrbr);
485 	writel((uint32_t)fec->tbd_base, &fec->eth->etdsr);
486 	writel((uint32_t)fec->rbd_base, &fec->eth->erdsr);
487 
488 	/*
489 	 * Initialize RxBD/TxBD rings
490 	 */
491 	if (fec_rbd_init(fec, FEC_RBD_NUM, FEC_MAX_PKT_SIZE) < 0) {
492 		free(fec->base_ptr);
493 		fec->base_ptr = NULL;
494 		return -ENOMEM;
495 	}
496 	fec_tbd_init(fec);
497 
498 
499 	if (fec->xcv_type != SEVENWIRE)
500 		miiphy_restart_aneg(dev);
501 
502 	fec_open(dev);
503 	return 0;
504 }
505 
506 /**
507  * Halt the FEC engine
508  * @param[in] dev Our device to handle
509  */
510 static void fec_halt(struct eth_device *dev)
511 {
512 	struct fec_priv *fec = (struct fec_priv *)dev->priv;
513 	int counter = 0xffff;
514 
515 	/*
516 	 * issue graceful stop command to the FEC transmitter if necessary
517 	 */
518 	writel(FEC_TCNTRL_GTS | readl(&fec->eth->x_cntrl),
519 			&fec->eth->x_cntrl);
520 
521 	debug("eth_halt: wait for stop regs\n");
522 	/*
523 	 * wait for graceful stop to register
524 	 */
525 	while ((counter--) && (!(readl(&fec->eth->ievent) & FEC_IEVENT_GRA)))
526 		udelay(1);
527 
528 	/*
529 	 * Disable SmartDMA tasks
530 	 */
531 	fec_tx_task_disable(fec);
532 	fec_rx_task_disable(fec);
533 
534 	/*
535 	 * Disable the Ethernet Controller
536 	 * Note: this will also reset the BD index counter!
537 	 */
538 	writel(readl(&fec->eth->ecntrl) & ~FEC_ECNTRL_ETHER_EN,
539 			&fec->eth->ecntrl);
540 	fec->rbd_index = 0;
541 	fec->tbd_index = 0;
542 	debug("eth_halt: done\n");
543 }
544 
545 /**
546  * Transmit one frame
547  * @param[in] dev Our ethernet device to handle
548  * @param[in] packet Pointer to the data to be transmitted
549  * @param[in] length Data count in bytes
550  * @return 0 on success
551  */
552 static int fec_send(struct eth_device *dev, volatile void* packet, int length)
553 {
554 	unsigned int status;
555 
556 	/*
557 	 * This routine transmits one frame.  This routine only accepts
558 	 * 6-byte Ethernet addresses.
559 	 */
560 	struct fec_priv *fec = (struct fec_priv *)dev->priv;
561 
562 	/*
563 	 * Check for valid length of data.
564 	 */
565 	if ((length > 1500) || (length <= 0)) {
566 		printf("Payload (%d) too large\n", length);
567 		return -1;
568 	}
569 
570 	/*
571 	 * Setup the transmit buffer
572 	 * Note: We are always using the first buffer for transmission,
573 	 * the second will be empty and only used to stop the DMA engine
574 	 */
575 	writew(length, &fec->tbd_base[fec->tbd_index].data_length);
576 	writel((uint32_t)packet, &fec->tbd_base[fec->tbd_index].data_pointer);
577 	/*
578 	 * update BD's status now
579 	 * This block:
580 	 * - is always the last in a chain (means no chain)
581 	 * - should transmitt the CRC
582 	 * - might be the last BD in the list, so the address counter should
583 	 *   wrap (-> keep the WRAP flag)
584 	 */
585 	status = readw(&fec->tbd_base[fec->tbd_index].status) & FEC_TBD_WRAP;
586 	status |= FEC_TBD_LAST | FEC_TBD_TC | FEC_TBD_READY;
587 	writew(status, &fec->tbd_base[fec->tbd_index].status);
588 
589 	/*
590 	 * Enable SmartDMA transmit task
591 	 */
592 	fec_tx_task_enable(fec);
593 
594 	/*
595 	 * wait until frame is sent .
596 	 */
597 	while (readw(&fec->tbd_base[fec->tbd_index].status) & FEC_TBD_READY) {
598 		udelay(1);
599 	}
600 	debug("fec_send: status 0x%x index %d\n",
601 			readw(&fec->tbd_base[fec->tbd_index].status),
602 			fec->tbd_index);
603 	/* for next transmission use the other buffer */
604 	if (fec->tbd_index)
605 		fec->tbd_index = 0;
606 	else
607 		fec->tbd_index = 1;
608 
609 	return 0;
610 }
611 
612 /**
613  * Pull one frame from the card
614  * @param[in] dev Our ethernet device to handle
615  * @return Length of packet read
616  */
617 static int fec_recv(struct eth_device *dev)
618 {
619 	struct fec_priv *fec = (struct fec_priv *)dev->priv;
620 	struct fec_bd *rbd = &fec->rbd_base[fec->rbd_index];
621 	unsigned long ievent;
622 	int frame_length, len = 0;
623 	struct nbuf *frame;
624 	uint16_t bd_status;
625 	uchar buff[FEC_MAX_PKT_SIZE];
626 
627 	/*
628 	 * Check if any critical events have happened
629 	 */
630 	ievent = readl(&fec->eth->ievent);
631 	writel(ievent, &fec->eth->ievent);
632 	debug("fec_recv: ievent 0x%x\n", ievent);
633 	if (ievent & FEC_IEVENT_BABR) {
634 		fec_halt(dev);
635 		fec_init(dev, fec->bd);
636 		printf("some error: 0x%08lx\n", ievent);
637 		return 0;
638 	}
639 	if (ievent & FEC_IEVENT_HBERR) {
640 		/* Heartbeat error */
641 		writel(0x00000001 | readl(&fec->eth->x_cntrl),
642 				&fec->eth->x_cntrl);
643 	}
644 	if (ievent & FEC_IEVENT_GRA) {
645 		/* Graceful stop complete */
646 		if (readl(&fec->eth->x_cntrl) & 0x00000001) {
647 			fec_halt(dev);
648 			writel(~0x00000001 & readl(&fec->eth->x_cntrl),
649 					&fec->eth->x_cntrl);
650 			fec_init(dev, fec->bd);
651 		}
652 	}
653 
654 	/*
655 	 * ensure reading the right buffer status
656 	 */
657 	bd_status = readw(&rbd->status);
658 	debug("fec_recv: status 0x%x\n", bd_status);
659 
660 	if (!(bd_status & FEC_RBD_EMPTY)) {
661 		if ((bd_status & FEC_RBD_LAST) && !(bd_status & FEC_RBD_ERR) &&
662 			((readw(&rbd->data_length) - 4) > 14)) {
663 			/*
664 			 * Get buffer address and size
665 			 */
666 			frame = (struct nbuf *)readl(&rbd->data_pointer);
667 			frame_length = readw(&rbd->data_length) - 4;
668 			/*
669 			 *  Fill the buffer and pass it to upper layers
670 			 */
671 			memcpy(buff, frame->data, frame_length);
672 			NetReceive(buff, frame_length);
673 			len = frame_length;
674 		} else {
675 			if (bd_status & FEC_RBD_ERR)
676 				printf("error frame: 0x%08lx 0x%08x\n",
677 						(ulong)rbd->data_pointer,
678 						bd_status);
679 		}
680 		/*
681 		 * free the current buffer, restart the engine
682 		 * and move forward to the next buffer
683 		 */
684 		fec_rbd_clean(fec->rbd_index == (FEC_RBD_NUM - 1) ? 1 : 0, rbd);
685 		fec_rx_task_enable(fec);
686 		fec->rbd_index = (fec->rbd_index + 1) % FEC_RBD_NUM;
687 	}
688 	debug("fec_recv: stop\n");
689 
690 	return len;
691 }
692 
693 static int fec_probe(bd_t *bd, int dev_id, int phy_id, uint32_t base_addr)
694 {
695 	struct eth_device *edev;
696 	struct fec_priv *fec;
697 	unsigned char ethaddr[6];
698 	uint32_t start;
699 	int ret = 0;
700 
701 	/* create and fill edev struct */
702 	edev = (struct eth_device *)malloc(sizeof(struct eth_device));
703 	if (!edev) {
704 		puts("fec_mxc: not enough malloc memory for eth_device\n");
705 		ret = -ENOMEM;
706 		goto err1;
707 	}
708 
709 	fec = (struct fec_priv *)malloc(sizeof(struct fec_priv));
710 	if (!fec) {
711 		puts("fec_mxc: not enough malloc memory for fec_priv\n");
712 		ret = -ENOMEM;
713 		goto err2;
714 	}
715 
716 	memset(edev, 0, sizeof(*edev));
717 	memset(fec, 0, sizeof(*fec));
718 
719 	edev->priv = fec;
720 	edev->init = fec_init;
721 	edev->send = fec_send;
722 	edev->recv = fec_recv;
723 	edev->halt = fec_halt;
724 	edev->write_hwaddr = fec_set_hwaddr;
725 
726 	fec->eth = (struct ethernet_regs *)base_addr;
727 	fec->bd = bd;
728 
729 	fec->xcv_type = CONFIG_FEC_XCV_TYPE;
730 
731 	/* Reset chip. */
732 	writel(readl(&fec->eth->ecntrl) | FEC_ECNTRL_RESET, &fec->eth->ecntrl);
733 	start = get_timer(0);
734 	while (readl(&fec->eth->ecntrl) & FEC_ECNTRL_RESET) {
735 		if (get_timer(start) > (CONFIG_SYS_HZ * 5)) {
736 			printf("FEC MXC: Timeout reseting chip\n");
737 			goto err3;
738 		}
739 		udelay(10);
740 	}
741 
742 	/*
743 	 * Set interrupt mask register
744 	 */
745 	writel(0x00000000, &fec->eth->imask);
746 
747 	/*
748 	 * Clear FEC-Lite interrupt event register(IEVENT)
749 	 */
750 	writel(0xffffffff, &fec->eth->ievent);
751 
752 	/*
753 	 * Set FEC-Lite receive control register(R_CNTRL):
754 	 */
755 	/*
756 	 * Frame length=1518; MII mode;
757 	 */
758 	writel((PKTSIZE << FEC_RCNTRL_MAX_FL_SHIFT) | FEC_RCNTRL_FCE |
759 		FEC_RCNTRL_MII_MODE, &fec->eth->r_cntrl);
760 	fec_mii_setspeed(fec);
761 
762 	if (dev_id == -1) {
763 		sprintf(edev->name, "FEC");
764 		fec->dev_id = 0;
765 	} else {
766 		sprintf(edev->name, "FEC%i", dev_id);
767 		fec->dev_id = dev_id;
768 	}
769 	fec->phy_id = phy_id;
770 
771 	miiphy_register(edev->name, fec_miiphy_read, fec_miiphy_write);
772 
773 	eth_register(edev);
774 
775 	if (fec_get_hwaddr(edev, ethaddr) == 0) {
776 		debug("got MAC address from fuse: %pM\n", ethaddr);
777 		memcpy(edev->enetaddr, ethaddr, 6);
778 	}
779 
780 	return ret;
781 
782 err3:
783 	free(fec);
784 err2:
785 	free(edev);
786 err1:
787 	return ret;
788 }
789 
790 #ifndef	CONFIG_FEC_MXC_MULTI
791 int fecmxc_initialize(bd_t *bd)
792 {
793 	int lout = 1;
794 
795 	debug("eth_init: fec_probe(bd)\n");
796 	lout = fec_probe(bd, -1, CONFIG_FEC_MXC_PHYADDR, IMX_FEC_BASE);
797 
798 	return lout;
799 }
800 #endif
801 
802 int fecmxc_initialize_multi(bd_t *bd, int dev_id, int phy_id, uint32_t addr)
803 {
804 	int lout = 1;
805 
806 	debug("eth_init: fec_probe(bd, %i, %i) @ %08x\n", dev_id, phy_id, addr);
807 	lout = fec_probe(bd, dev_id, phy_id, addr);
808 
809 	return lout;
810 }
811 
812 int fecmxc_register_mii_postcall(struct eth_device *dev, int (*cb)(int))
813 {
814 	struct fec_priv *fec = (struct fec_priv *)dev->priv;
815 	fec->mii_postcall = cb;
816 	return 0;
817 }
818