xref: /rk3399_rockchip-uboot/drivers/net/enc28j60.c (revision 4e0fbb98fcca8cee2995debc554fa98d59adefb0)
1 /*
2  * (C) Copyright 2010
3  * Reinhard Meyer, EMK Elektronik, reinhard.meyer@emk-elektronik.de
4  * Martin Krause, Martin.Krause@tqs.de
5  * reworked original enc28j60.c
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 as
9  * published by the Free Software Foundation; either version 2 of
10  * 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  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
20  * MA 02111-1307 USA
21  */
22 
23 #include <common.h>
24 #include <net.h>
25 #include <spi.h>
26 #include <malloc.h>
27 #include <netdev.h>
28 #include <miiphy.h>
29 #include "enc28j60.h"
30 
31 /*
32  * IMPORTANT: spi_claim_bus() and spi_release_bus()
33  * are called at begin and end of each of the following functions:
34  * enc_miiphy_read(), enc_miiphy_write(), enc_write_hwaddr(),
35  * enc_init(), enc_recv(), enc_send(), enc_halt()
36  * ALL other functions assume that the bus has already been claimed!
37  * Since NetReceive() might call enc_send() in return, the bus must be
38  * released, NetReceive() called and claimed again.
39  */
40 
41 /*
42  * Controller memory layout.
43  * We only allow 1 frame for transmission and reserve the rest
44  * for reception to handle as many broadcast packets as possible.
45  * Also use the memory from 0x0000 for receiver buffer. See errata pt. 5
46  * 0x0000 - 0x19ff 6656 bytes receive buffer
47  * 0x1a00 - 0x1fff 1536 bytes transmit buffer =
48  * control(1)+frame(1518)+status(7)+reserve(10).
49  */
50 #define ENC_RX_BUF_START	0x0000
51 #define ENC_RX_BUF_END		0x19ff
52 #define ENC_TX_BUF_START	0x1a00
53 #define ENC_TX_BUF_END		0x1fff
54 #define ENC_MAX_FRM_LEN		1518
55 #define RX_RESET_COUNTER	1000
56 
57 /*
58  * For non data transfer functions, like phy read/write, set hwaddr, init
59  * we do not need a full, time consuming init including link ready wait.
60  * This enum helps to bring the chip through the minimum necessary inits.
61  */
62 enum enc_initstate {none=0, setupdone, linkready};
63 typedef struct enc_device {
64 	struct eth_device	*dev;	/* back pointer */
65 	struct spi_slave	*slave;
66 	int			rx_reset_counter;
67 	u16			next_pointer;
68 	u8			bank;	/* current bank in enc28j60 */
69 	enum enc_initstate	initstate;
70 } enc_dev_t;
71 
72 /*
73  * enc_bset:		set bits in a common register
74  * enc_bclr:		clear bits in a common register
75  *
76  * making the reg parameter u8 will give a compile time warning if the
77  * functions are called with a register not accessible in all Banks
78  */
79 static void enc_bset(enc_dev_t *enc, const u8 reg, const u8 data)
80 {
81 	u8 dout[2];
82 
83 	dout[0] = CMD_BFS(reg);
84 	dout[1] = data;
85 	spi_xfer(enc->slave, 2 * 8, dout, NULL,
86 		SPI_XFER_BEGIN | SPI_XFER_END);
87 }
88 
89 static void enc_bclr(enc_dev_t *enc, const u8 reg, const u8 data)
90 {
91 	u8 dout[2];
92 
93 	dout[0] = CMD_BFC(reg);
94 	dout[1] = data;
95 	spi_xfer(enc->slave, 2 * 8, dout, NULL,
96 		SPI_XFER_BEGIN | SPI_XFER_END);
97 }
98 
99 /*
100  * high byte of the register contains bank number:
101  * 0: no bank switch necessary
102  * 1: switch to bank 0
103  * 2: switch to bank 1
104  * 3: switch to bank 2
105  * 4: switch to bank 3
106  */
107 static void enc_set_bank(enc_dev_t *enc, const u16 reg)
108 {
109 	u8 newbank = reg >> 8;
110 
111 	if (newbank == 0 || newbank == enc->bank)
112 		return;
113 	switch (newbank) {
114 	case 1:
115 		enc_bclr(enc, CTL_REG_ECON1,
116 			ENC_ECON1_BSEL0 | ENC_ECON1_BSEL1);
117 		break;
118 	case 2:
119 		enc_bset(enc, CTL_REG_ECON1, ENC_ECON1_BSEL0);
120 		enc_bclr(enc, CTL_REG_ECON1, ENC_ECON1_BSEL1);
121 		break;
122 	case 3:
123 		enc_bclr(enc, CTL_REG_ECON1, ENC_ECON1_BSEL0);
124 		enc_bset(enc, CTL_REG_ECON1, ENC_ECON1_BSEL1);
125 		break;
126 	case 4:
127 		enc_bset(enc, CTL_REG_ECON1,
128 			ENC_ECON1_BSEL0 | ENC_ECON1_BSEL1);
129 		break;
130 	}
131 	enc->bank = newbank;
132 }
133 
134 /*
135  * local functions to access SPI
136  *
137  * reg: register inside ENC28J60
138  * data: 8/16 bits to write
139  * c: number of retries
140  *
141  * enc_r8:		read 8 bits
142  * enc_r16:		read 16 bits
143  * enc_w8:		write 8 bits
144  * enc_w16:		write 16 bits
145  * enc_w8_retry:	write 8 bits, verify and retry
146  * enc_rbuf:		read from ENC28J60 into buffer
147  * enc_wbuf:		write from buffer into ENC28J60
148  */
149 
150 /*
151  * MAC and MII registers need a 3 byte SPI transfer to read,
152  * all other registers need a 2 byte SPI transfer.
153  */
154 static int enc_reg2nbytes(const u16 reg)
155 {
156 	/* check if MAC or MII register */
157 	return ((reg >= CTL_REG_MACON1 && reg <= CTL_REG_MIRDH) ||
158 		(reg >= CTL_REG_MAADR1 && reg <= CTL_REG_MAADR4) ||
159 		(reg == CTL_REG_MISTAT)) ? 3 : 2;
160 }
161 
162 /*
163  * Read a byte register
164  */
165 static u8 enc_r8(enc_dev_t *enc, const u16 reg)
166 {
167 	u8 dout[3];
168 	u8 din[3];
169 	int nbytes = enc_reg2nbytes(reg);
170 
171 	enc_set_bank(enc, reg);
172 	dout[0] = CMD_RCR(reg);
173 	spi_xfer(enc->slave, nbytes * 8, dout, din,
174 		SPI_XFER_BEGIN | SPI_XFER_END);
175 	return din[nbytes-1];
176 }
177 
178 /*
179  * Read a L/H register pair and return a word.
180  * Must be called with the L register's address.
181  */
182 static u16 enc_r16(enc_dev_t *enc, const u16 reg)
183 {
184 	u8 dout[3];
185 	u8 din[3];
186 	u16 result;
187 	int nbytes = enc_reg2nbytes(reg);
188 
189 	enc_set_bank(enc, reg);
190 	dout[0] = CMD_RCR(reg);
191 	spi_xfer(enc->slave, nbytes * 8, dout, din,
192 		SPI_XFER_BEGIN | SPI_XFER_END);
193 	result = din[nbytes-1];
194 	dout[0]++; /* next register */
195 	spi_xfer(enc->slave, nbytes * 8, dout, din,
196 		SPI_XFER_BEGIN | SPI_XFER_END);
197 	result |= din[nbytes-1] << 8;
198 	return result;
199 }
200 
201 /*
202  * Write a byte register
203  */
204 static void enc_w8(enc_dev_t *enc, const u16 reg, const u8 data)
205 {
206 	u8 dout[2];
207 
208 	enc_set_bank(enc, reg);
209 	dout[0] = CMD_WCR(reg);
210 	dout[1] = data;
211 	spi_xfer(enc->slave, 2 * 8, dout, NULL,
212 		SPI_XFER_BEGIN | SPI_XFER_END);
213 }
214 
215 /*
216  * Write a L/H register pair.
217  * Must be called with the L register's address.
218  */
219 static void enc_w16(enc_dev_t *enc, const u16 reg, const u16 data)
220 {
221 	u8 dout[2];
222 
223 	enc_set_bank(enc, reg);
224 	dout[0] = CMD_WCR(reg);
225 	dout[1] = data;
226 	spi_xfer(enc->slave, 2 * 8, dout, NULL,
227 		SPI_XFER_BEGIN | SPI_XFER_END);
228 	dout[0]++; /* next register */
229 	dout[1] = data >> 8;
230 	spi_xfer(enc->slave, 2 * 8, dout, NULL,
231 		SPI_XFER_BEGIN | SPI_XFER_END);
232 }
233 
234 /*
235  * Write a byte register, verify and retry
236  */
237 static void enc_w8_retry(enc_dev_t *enc, const u16 reg, const u8 data, const int c)
238 {
239 	u8 dout[2];
240 	u8 readback;
241 	int i;
242 
243 	enc_set_bank(enc, reg);
244 	for (i = 0; i < c; i++) {
245 		dout[0] = CMD_WCR(reg);
246 		dout[1] = data;
247 		spi_xfer(enc->slave, 2 * 8, dout, NULL,
248 			SPI_XFER_BEGIN | SPI_XFER_END);
249 		readback = enc_r8(enc, reg);
250 		if (readback == data)
251 			break;
252 		/* wait 1ms */
253 		udelay(1000);
254 	}
255 	if (i == c) {
256 		printf("%s: write reg 0x%03x failed\n", enc->dev->name, reg);
257 	}
258 }
259 
260 /*
261  * Read ENC RAM into buffer
262  */
263 static void enc_rbuf(enc_dev_t *enc, const u16 length, u8 *buf)
264 {
265 	u8 dout[1];
266 
267 	dout[0] = CMD_RBM;
268 	spi_xfer(enc->slave, 8, dout, NULL, SPI_XFER_BEGIN);
269 	spi_xfer(enc->slave, length * 8, NULL, buf, SPI_XFER_END);
270 #ifdef DEBUG
271 	puts("Rx:\n");
272 	print_buffer(0, buf, 1, length, 0);
273 #endif
274 }
275 
276 /*
277  * Write buffer into ENC RAM
278  */
279 static void enc_wbuf(enc_dev_t *enc, const u16 length, const u8 *buf, const u8 control)
280 {
281 	u8 dout[2];
282 	dout[0] = CMD_WBM;
283 	dout[1] = control;
284 	spi_xfer(enc->slave, 2 * 8, dout, NULL, SPI_XFER_BEGIN);
285 	spi_xfer(enc->slave, length * 8, buf, NULL, SPI_XFER_END);
286 #ifdef DEBUG
287 	puts("Tx:\n");
288 	print_buffer(0, buf, 1, length, 0);
289 #endif
290 }
291 
292 /*
293  * Try to claim the SPI bus.
294  * Print error message on failure.
295  */
296 static int enc_claim_bus(enc_dev_t *enc)
297 {
298 	int rc = spi_claim_bus(enc->slave);
299 	if (rc)
300 		printf("%s: failed to claim SPI bus\n", enc->dev->name);
301 	return rc;
302 }
303 
304 /*
305  * Release previously claimed SPI bus.
306  * This function is mainly for symmetry to enc_claim_bus().
307  * Let the toolchain decide to inline it...
308  */
309 static void enc_release_bus(enc_dev_t *enc)
310 {
311 	spi_release_bus(enc->slave);
312 }
313 
314 /*
315  * Read PHY register
316  */
317 static u16 enc_phy_read(enc_dev_t *enc, const u8 addr)
318 {
319 	uint64_t etime;
320 	u8 status;
321 
322 	enc_w8(enc, CTL_REG_MIREGADR, addr);
323 	enc_w8(enc, CTL_REG_MICMD, ENC_MICMD_MIIRD);
324 	/* 1 second timeout - only happens on hardware problem */
325 	etime = get_ticks() + get_tbclk();
326 	/* poll MISTAT.BUSY bit until operation is complete */
327 	do
328 	{
329 		status = enc_r8(enc, CTL_REG_MISTAT);
330 	} while (get_ticks() <= etime && (status & ENC_MISTAT_BUSY));
331 	if (status & ENC_MISTAT_BUSY) {
332 		printf("%s: timeout reading phy\n", enc->dev->name);
333 		return 0;
334 	}
335 	enc_w8(enc, CTL_REG_MICMD, 0);
336 	return enc_r16(enc, CTL_REG_MIRDL);
337 }
338 
339 /*
340  * Write PHY register
341  */
342 static void enc_phy_write(enc_dev_t *enc, const u8 addr, const u16 data)
343 {
344 	uint64_t etime;
345 	u8 status;
346 
347 	enc_w8(enc, CTL_REG_MIREGADR, addr);
348 	enc_w16(enc, CTL_REG_MIWRL, data);
349 	/* 1 second timeout - only happens on hardware problem */
350 	etime = get_ticks() + get_tbclk();
351 	/* poll MISTAT.BUSY bit until operation is complete */
352 	do
353 	{
354 		status = enc_r8(enc, CTL_REG_MISTAT);
355 	} while (get_ticks() <= etime && (status & ENC_MISTAT_BUSY));
356 	if (status & ENC_MISTAT_BUSY) {
357 		printf("%s: timeout writing phy\n", enc->dev->name);
358 		return;
359 	}
360 }
361 
362 /*
363  * Verify link status, wait if necessary
364  *
365  * Note: with a 10 MBit/s only PHY there is no autonegotiation possible,
366  * half/full duplex is a pure setup matter. For the time being, this driver
367  * will setup in half duplex mode only.
368  */
369 static int enc_phy_link_wait(enc_dev_t *enc)
370 {
371 	u16 status;
372 	int duplex;
373 	uint64_t etime;
374 
375 #ifdef CONFIG_ENC_SILENTLINK
376 	/* check if we have a link, then just return */
377 	status = enc_phy_read(enc, PHY_REG_PHSTAT1);
378 	if (status & ENC_PHSTAT1_LLSTAT)
379 		return 0;
380 #endif
381 
382 	/* wait for link with 1 second timeout */
383 	etime = get_ticks() + get_tbclk();
384 	while (get_ticks() <= etime) {
385 		status = enc_phy_read(enc, PHY_REG_PHSTAT1);
386 		if (status & ENC_PHSTAT1_LLSTAT) {
387 			/* now we have a link */
388 			status = enc_phy_read(enc, PHY_REG_PHSTAT2);
389 			duplex = (status & ENC_PHSTAT2_DPXSTAT) ? 1 : 0;
390 			printf("%s: link up, 10Mbps %s-duplex\n",
391 				enc->dev->name, duplex ? "full" : "half");
392 			return 0;
393 		}
394 		udelay(1000);
395 	}
396 
397 	/* timeout occured */
398 	printf("%s: link down\n", enc->dev->name);
399 	return 1;
400 }
401 
402 /*
403  * This function resets the receiver only.
404  */
405 static void enc_reset_rx(enc_dev_t *enc)
406 {
407 	u8 econ1;
408 
409 	econ1 = enc_r8(enc, CTL_REG_ECON1);
410 	if ((econ1 & ENC_ECON1_RXRST) == 0) {
411 		enc_bset(enc, CTL_REG_ECON1, ENC_ECON1_RXRST);
412 		enc->rx_reset_counter = RX_RESET_COUNTER;
413 	}
414 }
415 
416 /*
417  * Reset receiver and reenable it.
418  */
419 static void enc_reset_rx_call(enc_dev_t *enc)
420 {
421 	enc_bclr(enc, CTL_REG_ECON1, ENC_ECON1_RXRST);
422 	enc_bset(enc, CTL_REG_ECON1, ENC_ECON1_RXEN);
423 }
424 
425 /*
426  * Copy a packet from the receive ring and forward it to
427  * the protocol stack.
428  */
429 static void enc_receive(enc_dev_t *enc)
430 {
431 	u8 *packet = (u8 *)NetRxPackets[0];
432 	u16 pkt_len;
433 	u16 copy_len;
434 	u16 status;
435 	u8 eir_reg;
436 	u8 pkt_cnt = 0;
437 	u16 rxbuf_rdpt;
438 	u8 hbuf[6];
439 
440 	enc_w16(enc, CTL_REG_ERDPTL, enc->next_pointer);
441 	do {
442 		enc_rbuf(enc, 6, hbuf);
443 		enc->next_pointer = hbuf[0] | (hbuf[1] << 8);
444 		pkt_len = hbuf[2] | (hbuf[3] << 8);
445 		status = hbuf[4] | (hbuf[5] << 8);
446 		debug("next_pointer=$%04x pkt_len=%u status=$%04x\n",
447 			enc->next_pointer, pkt_len, status);
448 		if (pkt_len <= ENC_MAX_FRM_LEN)
449 			copy_len = pkt_len;
450 		else
451 			copy_len = 0;
452 		if ((status & (1L << 7)) == 0) /* check Received Ok bit */
453 			copy_len = 0;
454 		/* check if next pointer is resonable */
455 		if (enc->next_pointer >= ENC_TX_BUF_START)
456 			copy_len = 0;
457 		if (copy_len > 0) {
458 			enc_rbuf(enc, copy_len, packet);
459 		}
460 		/* advance read pointer to next pointer */
461 		enc_w16(enc, CTL_REG_ERDPTL, enc->next_pointer);
462 		/* decrease packet counter */
463 		enc_bset(enc, CTL_REG_ECON2, ENC_ECON2_PKTDEC);
464 		/*
465 		 * Only odd values should be written to ERXRDPTL,
466 		 * see errata B4 pt.13
467 		 */
468 		rxbuf_rdpt = enc->next_pointer - 1;
469 		if ((rxbuf_rdpt < enc_r16(enc, CTL_REG_ERXSTL)) ||
470 			(rxbuf_rdpt > enc_r16(enc, CTL_REG_ERXNDL))) {
471 			enc_w16(enc, CTL_REG_ERXRDPTL,
472 				enc_r16(enc, CTL_REG_ERXNDL));
473 		} else {
474 			enc_w16(enc, CTL_REG_ERXRDPTL, rxbuf_rdpt);
475 		}
476 		/* read pktcnt */
477 		pkt_cnt = enc_r8(enc, CTL_REG_EPKTCNT);
478 		if (copy_len == 0) {
479 			eir_reg = enc_r8(enc, CTL_REG_EIR);
480 			enc_reset_rx(enc);
481 			printf("%s: receive copy_len=0\n", enc->dev->name);
482 			continue;
483 		}
484 		/*
485 		 * Because NetReceive() might call enc_send(), we need to
486 		 * release the SPI bus, call NetReceive(), reclaim the bus
487 		 */
488 		enc_release_bus(enc);
489 		NetReceive(packet, pkt_len);
490 		if (enc_claim_bus(enc))
491 			return;
492 		eir_reg = enc_r8(enc, CTL_REG_EIR);
493 	} while (pkt_cnt);
494 	/* Use EPKTCNT not EIR.PKTIF flag, see errata pt. 6 */
495 }
496 
497 /*
498  * Poll for completely received packets.
499  */
500 static void enc_poll(enc_dev_t *enc)
501 {
502 	u8 eir_reg;
503 	u8 estat_reg;
504 	u8 pkt_cnt;
505 
506 #ifdef CONFIG_USE_IRQ
507 	/* clear global interrupt enable bit in enc28j60 */
508 	enc_bclr(enc, CTL_REG_EIE, ENC_EIE_INTIE);
509 #endif
510 	estat_reg = enc_r8(enc, CTL_REG_ESTAT);
511 	eir_reg = enc_r8(enc, CTL_REG_EIR);
512 	if (eir_reg & ENC_EIR_TXIF) {
513 		/* clear TXIF bit in EIR */
514 		enc_bclr(enc, CTL_REG_EIR, ENC_EIR_TXIF);
515 	}
516 	/* We have to use pktcnt and not pktif bit, see errata pt. 6 */
517 	pkt_cnt = enc_r8(enc, CTL_REG_EPKTCNT);
518 	if (pkt_cnt > 0) {
519 		if ((eir_reg & ENC_EIR_PKTIF) == 0) {
520 			debug("enc_poll: pkt cnt > 0, but pktif not set\n");
521 		}
522 		enc_receive(enc);
523 		/*
524 		 * clear PKTIF bit in EIR, this should not need to be done
525 		 * but it seems like we get problems if we do not
526 		 */
527 		enc_bclr(enc, CTL_REG_EIR, ENC_EIR_PKTIF);
528 	}
529 	if (eir_reg & ENC_EIR_RXERIF) {
530 		printf("%s: rx error\n", enc->dev->name);
531 		enc_bclr(enc, CTL_REG_EIR, ENC_EIR_RXERIF);
532 	}
533 	if (eir_reg & ENC_EIR_TXERIF) {
534 		printf("%s: tx error\n", enc->dev->name);
535 		enc_bclr(enc, CTL_REG_EIR, ENC_EIR_TXERIF);
536 	}
537 #ifdef CONFIG_USE_IRQ
538 	/* set global interrupt enable bit in enc28j60 */
539 	enc_bset(enc, CTL_REG_EIE, ENC_EIE_INTIE);
540 #endif
541 }
542 
543 /*
544  * Completely Reset the ENC
545  */
546 static void enc_reset(enc_dev_t *enc)
547 {
548 	u8 dout[1];
549 
550 	dout[0] = CMD_SRC;
551 	spi_xfer(enc->slave, 8, dout, NULL,
552 		SPI_XFER_BEGIN | SPI_XFER_END);
553 	/* sleep 1 ms. See errata pt. 2 */
554 	udelay(1000);
555 }
556 
557 /*
558  * Initialisation data for most of the ENC registers
559  */
560 static const u16 enc_initdata[] = {
561 	/*
562 	 * Setup the buffer space. The reset values are valid for the
563 	 * other pointers.
564 	 *
565 	 * We shall not write to ERXST, see errata pt. 5. Instead we
566 	 * have to make sure that ENC_RX_BUS_START is 0.
567 	 */
568 	CTL_REG_ERXSTL, ENC_RX_BUF_START,
569 	CTL_REG_ERXSTH, ENC_RX_BUF_START >> 8,
570 	CTL_REG_ERXNDL, ENC_RX_BUF_END,
571 	CTL_REG_ERXNDH, ENC_RX_BUF_END >> 8,
572 	CTL_REG_ERDPTL, ENC_RX_BUF_START,
573 	CTL_REG_ERDPTH, ENC_RX_BUF_START >> 8,
574 	/*
575 	 * Set the filter to receive only good-CRC, unicast and broadcast
576 	 * frames.
577 	 * Note: some DHCP servers return their answers as broadcasts!
578 	 * So its unwise to remove broadcast from this. This driver
579 	 * might incur receiver overruns with packet loss on a broadcast
580 	 * flooded network.
581 	 */
582 	CTL_REG_ERXFCON, ENC_RFR_BCEN | ENC_RFR_UCEN | ENC_RFR_CRCEN,
583 
584 	/* enable MAC to receive frames */
585 	CTL_REG_MACON1,
586 		ENC_MACON1_MARXEN | ENC_MACON1_TXPAUS | ENC_MACON1_RXPAUS,
587 
588 	/* configure pad, tx-crc and duplex */
589 	CTL_REG_MACON3,
590 		ENC_MACON3_PADCFG0 | ENC_MACON3_TXCRCEN |
591 		ENC_MACON3_FRMLNEN,
592 
593 	/* Allow infinite deferals if the medium is continously busy */
594 	CTL_REG_MACON4, ENC_MACON4_DEFER,
595 
596 	/* Late collisions occur beyond 63 bytes */
597 	CTL_REG_MACLCON2, 63,
598 
599 	/*
600 	 * Set (low byte) Non-Back-to_Back Inter-Packet Gap.
601 	 * Recommended 0x12
602 	 */
603 	CTL_REG_MAIPGL, 0x12,
604 
605 	/*
606 	 * Set (high byte) Non-Back-to_Back Inter-Packet Gap.
607 	 * Recommended 0x0c for half-duplex. Nothing for full-duplex
608 	 */
609 	CTL_REG_MAIPGH, 0x0C,
610 
611 	/* set maximum frame length */
612 	CTL_REG_MAMXFLL, ENC_MAX_FRM_LEN,
613 	CTL_REG_MAMXFLH, ENC_MAX_FRM_LEN >> 8,
614 
615 	/*
616 	 * Set MAC back-to-back inter-packet gap.
617 	 * Recommended 0x12 for half duplex
618 	 * and 0x15 for full duplex.
619 	 */
620 	CTL_REG_MABBIPG, 0x12,
621 
622 	/* end of table */
623 	0xffff
624 };
625 
626 /*
627  * Wait for the XTAL oscillator to become ready
628  */
629 static int enc_clock_wait(enc_dev_t *enc)
630 {
631 	uint64_t etime;
632 
633 	/* one second timeout */
634 	etime = get_ticks() + get_tbclk();
635 
636 	/*
637 	 * Wait for CLKRDY to become set (i.e., check that we can
638 	 * communicate with the ENC)
639 	 */
640 	do
641 	{
642 		if (enc_r8(enc, CTL_REG_ESTAT) & ENC_ESTAT_CLKRDY)
643 			return 0;
644 	} while (get_ticks() <= etime);
645 
646 	printf("%s: timeout waiting for CLKRDY\n", enc->dev->name);
647 	return -1;
648 }
649 
650 /*
651  * Write the MAC address into the ENC
652  */
653 static int enc_write_macaddr(enc_dev_t *enc)
654 {
655 	unsigned char *p = enc->dev->enetaddr;
656 
657 	enc_w8_retry(enc, CTL_REG_MAADR5, *p++, 5);
658 	enc_w8_retry(enc, CTL_REG_MAADR4, *p++, 5);
659 	enc_w8_retry(enc, CTL_REG_MAADR3, *p++, 5);
660 	enc_w8_retry(enc, CTL_REG_MAADR2, *p++, 5);
661 	enc_w8_retry(enc, CTL_REG_MAADR1, *p++, 5);
662 	enc_w8_retry(enc, CTL_REG_MAADR0, *p, 5);
663 	return 0;
664 }
665 
666 /*
667  * Setup most of the ENC registers
668  */
669 static int enc_setup(enc_dev_t *enc)
670 {
671 	u16 phid1 = 0;
672 	u16 phid2 = 0;
673 	const u16 *tp;
674 
675 	/* reset enc struct values */
676 	enc->next_pointer = ENC_RX_BUF_START;
677 	enc->rx_reset_counter = RX_RESET_COUNTER;
678 	enc->bank = 0xff;	/* invalidate current bank in enc28j60 */
679 
680 	/* verify PHY identification */
681 	phid1 = enc_phy_read(enc, PHY_REG_PHID1);
682 	phid2 = enc_phy_read(enc, PHY_REG_PHID2) & ENC_PHID2_MASK;
683 	if (phid1 != ENC_PHID1_VALUE || phid2 != ENC_PHID2_VALUE) {
684 		printf("%s: failed to identify PHY. Found %04x:%04x\n",
685 			enc->dev->name, phid1, phid2);
686 		return -1;
687 	}
688 
689 	/* now program registers */
690 	for (tp = enc_initdata; *tp != 0xffff; tp += 2)
691 		enc_w8_retry(enc, tp[0], tp[1], 10);
692 
693 	/*
694 	 * Prevent automatic loopback of data beeing transmitted by setting
695 	 * ENC_PHCON2_HDLDIS
696 	 */
697 	enc_phy_write(enc, PHY_REG_PHCON2, (1<<8));
698 
699 	/*
700 	 * LEDs configuration
701 	 * LEDA: LACFG = 0100 -> display link status
702 	 * LEDB: LBCFG = 0111 -> display TX & RX activity
703 	 * STRCH = 1 -> LED pulses
704 	 */
705 	enc_phy_write(enc, PHY_REG_PHLCON, 0x0472);
706 
707 	/* Reset PDPXMD-bit => half duplex */
708 	enc_phy_write(enc, PHY_REG_PHCON1, 0);
709 
710 #ifdef CONFIG_USE_IRQ
711 	/* enable interrupts */
712 	enc_bset(enc, CTL_REG_EIE, ENC_EIE_PKTIE);
713 	enc_bset(enc, CTL_REG_EIE, ENC_EIE_TXIE);
714 	enc_bset(enc, CTL_REG_EIE, ENC_EIE_RXERIE);
715 	enc_bset(enc, CTL_REG_EIE, ENC_EIE_TXERIE);
716 	enc_bset(enc, CTL_REG_EIE, ENC_EIE_INTIE);
717 #endif
718 
719 	return 0;
720 }
721 
722 /*
723  * Check if ENC has been initialized.
724  * If not, try to initialize it.
725  * Remember initialized state in struct.
726  */
727 static int enc_initcheck(enc_dev_t *enc, const enum enc_initstate requiredstate)
728 {
729 	if (enc->initstate >= requiredstate)
730 		return 0;
731 
732 	if (enc->initstate < setupdone) {
733 		/* Initialize the ENC only */
734 		enc_reset(enc);
735 		/* if any of functions fails, skip the rest and return an error */
736 		if (enc_clock_wait(enc) || enc_setup(enc) || enc_write_macaddr(enc)) {
737 			return -1;
738 		}
739 		enc->initstate = setupdone;
740 	}
741 	/* if that's all we need, return here */
742 	if (enc->initstate >= requiredstate)
743 		return 0;
744 
745 	/* now wait for link ready condition */
746 	if (enc_phy_link_wait(enc)) {
747 		return -1;
748 	}
749 	enc->initstate = linkready;
750 	return 0;
751 }
752 
753 #if defined(CONFIG_CMD_MII)
754 /*
755  * Read a PHY register.
756  *
757  * This function is registered with miiphy_register().
758  */
759 int enc_miiphy_read(const char *devname, u8 phy_adr, u8 reg, u16 *value)
760 {
761 	struct eth_device *dev = eth_get_dev_by_name(devname);
762 	enc_dev_t *enc;
763 
764 	if (!dev || phy_adr != 0)
765 		return -1;
766 
767 	enc = dev->priv;
768 	if (enc_claim_bus(enc))
769 		return -1;
770 	if (enc_initcheck(enc, setupdone)) {
771 		enc_release_bus(enc);
772 		return -1;
773 	}
774 	*value = enc_phy_read(enc, reg);
775 	enc_release_bus(enc);
776 	return 0;
777 }
778 
779 /*
780  * Write a PHY register.
781  *
782  * This function is registered with miiphy_register().
783  */
784 int enc_miiphy_write(const char *devname, u8 phy_adr, u8 reg, u16 value)
785 {
786 	struct eth_device *dev = eth_get_dev_by_name(devname);
787 	enc_dev_t *enc;
788 
789 	if (!dev || phy_adr != 0)
790 		return -1;
791 
792 	enc = dev->priv;
793 	if (enc_claim_bus(enc))
794 		return -1;
795 	if (enc_initcheck(enc, setupdone)) {
796 		enc_release_bus(enc);
797 		return -1;
798 	}
799 	enc_phy_write(enc, reg, value);
800 	enc_release_bus(enc);
801 	return 0;
802 }
803 #endif
804 
805 /*
806  * Write hardware (MAC) address.
807  *
808  * This function entered into eth_device structure.
809  */
810 static int enc_write_hwaddr(struct eth_device *dev)
811 {
812 	enc_dev_t *enc = dev->priv;
813 
814 	if (enc_claim_bus(enc))
815 		return -1;
816 	if (enc_initcheck(enc, setupdone)) {
817 		enc_release_bus(enc);
818 		return -1;
819 	}
820 	enc_release_bus(enc);
821 	return 0;
822 }
823 
824 /*
825  * Initialize ENC28J60 for use.
826  *
827  * This function entered into eth_device structure.
828  */
829 static int enc_init(struct eth_device *dev, bd_t *bis)
830 {
831 	enc_dev_t *enc = dev->priv;
832 
833 	if (enc_claim_bus(enc))
834 		return -1;
835 	if (enc_initcheck(enc, linkready)) {
836 		enc_release_bus(enc);
837 		return -1;
838 	}
839 	/* enable receive */
840 	enc_bset(enc, CTL_REG_ECON1, ENC_ECON1_RXEN);
841 	enc_release_bus(enc);
842 	return 0;
843 }
844 
845 /*
846  * Check for received packets.
847  *
848  * This function entered into eth_device structure.
849  */
850 static int enc_recv(struct eth_device *dev)
851 {
852 	enc_dev_t *enc = dev->priv;
853 
854 	if (enc_claim_bus(enc))
855 		return -1;
856 	if (enc_initcheck(enc, linkready)) {
857 		enc_release_bus(enc);
858 		return -1;
859 	}
860 	/* Check for dead receiver */
861 	if (enc->rx_reset_counter > 0)
862 		enc->rx_reset_counter--;
863 	else
864 		enc_reset_rx_call(enc);
865 	enc_poll(enc);
866 	enc_release_bus(enc);
867 	return 0;
868 }
869 
870 /*
871  * Send a packet.
872  *
873  * This function entered into eth_device structure.
874  *
875  * Should we wait here until we have a Link? Or shall we leave that to
876  * protocol retries?
877  */
878 static int enc_send(
879 	struct eth_device *dev,
880 	volatile void *packet,
881 	int length)
882 {
883 	enc_dev_t *enc = dev->priv;
884 
885 	if (enc_claim_bus(enc))
886 		return -1;
887 	if (enc_initcheck(enc, linkready)) {
888 		enc_release_bus(enc);
889 		return -1;
890 	}
891 	/* setup transmit pointers */
892 	enc_w16(enc, CTL_REG_EWRPTL, ENC_TX_BUF_START);
893 	enc_w16(enc, CTL_REG_ETXNDL, length + ENC_TX_BUF_START);
894 	enc_w16(enc, CTL_REG_ETXSTL, ENC_TX_BUF_START);
895 	/* write packet to ENC */
896 	enc_wbuf(enc, length, (u8 *) packet, 0x00);
897 	/*
898 	 * Check that the internal transmit logic has not been altered
899 	 * by excessive collisions. Reset transmitter if so.
900 	 * See Errata B4 12 and 14.
901 	 */
902 	if (enc_r8(enc, CTL_REG_EIR) & ENC_EIR_TXERIF) {
903 		enc_bset(enc, CTL_REG_ECON1, ENC_ECON1_TXRST);
904 		enc_bclr(enc, CTL_REG_ECON1, ENC_ECON1_TXRST);
905 	}
906 	enc_bclr(enc, CTL_REG_EIR, (ENC_EIR_TXERIF | ENC_EIR_TXIF));
907 	/* start transmitting */
908 	enc_bset(enc, CTL_REG_ECON1, ENC_ECON1_TXRTS);
909 	enc_release_bus(enc);
910 	return 0;
911 }
912 
913 /*
914  * Finish use of ENC.
915  *
916  * This function entered into eth_device structure.
917  */
918 static void enc_halt(struct eth_device *dev)
919 {
920 	enc_dev_t *enc = dev->priv;
921 
922 	if (enc_claim_bus(enc))
923 		return;
924 	/* Just disable receiver */
925 	enc_bclr(enc, CTL_REG_ECON1, ENC_ECON1_RXEN);
926 	enc_release_bus(enc);
927 }
928 
929 /*
930  * This is the only exported function.
931  *
932  * It may be called several times with different bus:cs combinations.
933  */
934 int enc28j60_initialize(unsigned int bus, unsigned int cs,
935 	unsigned int max_hz, unsigned int mode)
936 {
937 	struct eth_device *dev;
938 	enc_dev_t *enc;
939 
940 	/* try to allocate, check and clear eth_device object */
941 	dev = malloc(sizeof(*dev));
942 	if (!dev) {
943 		return -1;
944 	}
945 	memset(dev, 0, sizeof(*dev));
946 
947 	/* try to allocate, check and clear enc_dev_t object */
948 	enc = malloc(sizeof(*enc));
949 	if (!enc) {
950 		free(dev);
951 		return -1;
952 	}
953 	memset(enc, 0, sizeof(*enc));
954 
955 	/* try to setup the SPI slave */
956 	enc->slave = spi_setup_slave(bus, cs, max_hz, mode);
957 	if (!enc->slave) {
958 		printf("enc28j60: invalid SPI device %i:%i\n", bus, cs);
959 		free(enc);
960 		free(dev);
961 		return -1;
962 	}
963 
964 	enc->dev = dev;
965 	/* now fill the eth_device object */
966 	dev->priv = enc;
967 	dev->init = enc_init;
968 	dev->halt = enc_halt;
969 	dev->send = enc_send;
970 	dev->recv = enc_recv;
971 	dev->write_hwaddr = enc_write_hwaddr;
972 	sprintf(dev->name, "enc%i.%i", bus, cs);
973 	eth_register(dev);
974 #if defined(CONFIG_CMD_MII)
975 	miiphy_register(dev->name, enc_miiphy_read, enc_miiphy_write);
976 #endif
977 	return 0;
978 }
979