1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Microchip ENC28J60 ethernet driver (MAC + PHY)
4  *
5  * Copyright (C) 2007 Eurek srl
6  * Author: Claudio Lanconelli <lanconelli.claudio@eptar.com>
7  * based on enc28j60.c written by David Anders for 2.4 kernel version
8  *
9  * $Id: enc28j60.c,v 1.22 2007/12/20 10:47:01 claudio Exp $
10  */
11 
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/types.h>
15 #include <linux/fcntl.h>
16 #include <linux/interrupt.h>
17 #include <linux/property.h>
18 #include <linux/string.h>
19 #include <linux/errno.h>
20 #include <linux/netdevice.h>
21 #include <linux/etherdevice.h>
22 #include <linux/ethtool.h>
23 #include <linux/tcp.h>
24 #include <linux/skbuff.h>
25 #include <linux/delay.h>
26 #include <linux/spi/spi.h>
27 
28 #include "enc28j60_hw.h"
29 
30 #define DRV_NAME	"enc28j60"
31 #define DRV_VERSION	"1.02"
32 
33 #define SPI_OPLEN	1
34 
35 #define ENC28J60_MSG_DEFAULT	\
36 	(NETIF_MSG_PROBE | NETIF_MSG_IFUP | NETIF_MSG_IFDOWN | NETIF_MSG_LINK)
37 
38 /* Buffer size required for the largest SPI transfer (i.e., reading a
39  * frame).
40  */
41 #define SPI_TRANSFER_BUF_LEN	(4 + MAX_FRAMELEN)
42 
43 #define TX_TIMEOUT		(4 * HZ)
44 
45 /* Max TX retries in case of collision as suggested by errata datasheet */
46 #define MAX_TX_RETRYCOUNT	16
47 
48 enum {
49 	RXFILTER_NORMAL,
50 	RXFILTER_MULTI,
51 	RXFILTER_PROMISC
52 };
53 
54 /* Driver local data */
55 struct enc28j60_net {
56 	struct net_device *netdev;
57 	struct spi_device *spi;
58 	struct mutex lock;
59 	struct sk_buff *tx_skb;
60 	struct work_struct tx_work;
61 	struct work_struct irq_work;
62 	struct work_struct setrx_work;
63 	struct work_struct restart_work;
64 	u8 bank;		/* current register bank selected */
65 	u16 next_pk_ptr;	/* next packet pointer within FIFO */
66 	u16 max_pk_counter;	/* statistics: max packet counter */
67 	u16 tx_retry_count;
68 	bool hw_enable;
69 	bool full_duplex;
70 	int rxfilter;
71 	u32 msg_enable;
72 	u8 spi_transfer_buf[SPI_TRANSFER_BUF_LEN];
73 };
74 
75 /* use ethtool to change the level for any given device */
76 static struct {
77 	u32 msg_enable;
78 } debug = { -1 };
79 
80 /*
81  * SPI read buffer
82  * Wait for the SPI transfer and copy received data to destination.
83  */
84 static int
85 spi_read_buf(struct enc28j60_net *priv, int len, u8 *data)
86 {
87 	struct device *dev = &priv->spi->dev;
88 	u8 *rx_buf = priv->spi_transfer_buf + 4;
89 	u8 *tx_buf = priv->spi_transfer_buf;
90 	struct spi_transfer tx = {
91 		.tx_buf = tx_buf,
92 		.len = SPI_OPLEN,
93 	};
94 	struct spi_transfer rx = {
95 		.rx_buf = rx_buf,
96 		.len = len,
97 	};
98 	struct spi_message msg;
99 	int ret;
100 
101 	tx_buf[0] = ENC28J60_READ_BUF_MEM;
102 
103 	spi_message_init(&msg);
104 	spi_message_add_tail(&tx, &msg);
105 	spi_message_add_tail(&rx, &msg);
106 
107 	ret = spi_sync(priv->spi, &msg);
108 	if (ret == 0) {
109 		memcpy(data, rx_buf, len);
110 		ret = msg.status;
111 	}
112 	if (ret && netif_msg_drv(priv))
113 		dev_printk(KERN_DEBUG, dev, "%s() failed: ret = %d\n",
114 			   __func__, ret);
115 
116 	return ret;
117 }
118 
119 /*
120  * SPI write buffer
121  */
122 static int spi_write_buf(struct enc28j60_net *priv, int len, const u8 *data)
123 {
124 	struct device *dev = &priv->spi->dev;
125 	int ret;
126 
127 	if (len > SPI_TRANSFER_BUF_LEN - 1 || len <= 0)
128 		ret = -EINVAL;
129 	else {
130 		priv->spi_transfer_buf[0] = ENC28J60_WRITE_BUF_MEM;
131 		memcpy(&priv->spi_transfer_buf[1], data, len);
132 		ret = spi_write(priv->spi, priv->spi_transfer_buf, len + 1);
133 		if (ret && netif_msg_drv(priv))
134 			dev_printk(KERN_DEBUG, dev, "%s() failed: ret = %d\n",
135 				   __func__, ret);
136 	}
137 	return ret;
138 }
139 
140 /*
141  * basic SPI read operation
142  */
143 static u8 spi_read_op(struct enc28j60_net *priv, u8 op, u8 addr)
144 {
145 	struct device *dev = &priv->spi->dev;
146 	u8 tx_buf[2];
147 	u8 rx_buf[4];
148 	u8 val = 0;
149 	int ret;
150 	int slen = SPI_OPLEN;
151 
152 	/* do dummy read if needed */
153 	if (addr & SPRD_MASK)
154 		slen++;
155 
156 	tx_buf[0] = op | (addr & ADDR_MASK);
157 	ret = spi_write_then_read(priv->spi, tx_buf, 1, rx_buf, slen);
158 	if (ret)
159 		dev_printk(KERN_DEBUG, dev, "%s() failed: ret = %d\n",
160 			   __func__, ret);
161 	else
162 		val = rx_buf[slen - 1];
163 
164 	return val;
165 }
166 
167 /*
168  * basic SPI write operation
169  */
170 static int spi_write_op(struct enc28j60_net *priv, u8 op, u8 addr, u8 val)
171 {
172 	struct device *dev = &priv->spi->dev;
173 	int ret;
174 
175 	priv->spi_transfer_buf[0] = op | (addr & ADDR_MASK);
176 	priv->spi_transfer_buf[1] = val;
177 	ret = spi_write(priv->spi, priv->spi_transfer_buf, 2);
178 	if (ret && netif_msg_drv(priv))
179 		dev_printk(KERN_DEBUG, dev, "%s() failed: ret = %d\n",
180 			   __func__, ret);
181 	return ret;
182 }
183 
184 static void enc28j60_soft_reset(struct enc28j60_net *priv)
185 {
186 	spi_write_op(priv, ENC28J60_SOFT_RESET, 0, ENC28J60_SOFT_RESET);
187 	/* Errata workaround #1, CLKRDY check is unreliable,
188 	 * delay at least 1 ms instead */
189 	udelay(2000);
190 }
191 
192 /*
193  * select the current register bank if necessary
194  */
195 static void enc28j60_set_bank(struct enc28j60_net *priv, u8 addr)
196 {
197 	u8 b = (addr & BANK_MASK) >> 5;
198 
199 	/* These registers (EIE, EIR, ESTAT, ECON2, ECON1)
200 	 * are present in all banks, no need to switch bank.
201 	 */
202 	if (addr >= EIE && addr <= ECON1)
203 		return;
204 
205 	/* Clear or set each bank selection bit as needed */
206 	if ((b & ECON1_BSEL0) != (priv->bank & ECON1_BSEL0)) {
207 		if (b & ECON1_BSEL0)
208 			spi_write_op(priv, ENC28J60_BIT_FIELD_SET, ECON1,
209 					ECON1_BSEL0);
210 		else
211 			spi_write_op(priv, ENC28J60_BIT_FIELD_CLR, ECON1,
212 					ECON1_BSEL0);
213 	}
214 	if ((b & ECON1_BSEL1) != (priv->bank & ECON1_BSEL1)) {
215 		if (b & ECON1_BSEL1)
216 			spi_write_op(priv, ENC28J60_BIT_FIELD_SET, ECON1,
217 					ECON1_BSEL1);
218 		else
219 			spi_write_op(priv, ENC28J60_BIT_FIELD_CLR, ECON1,
220 					ECON1_BSEL1);
221 	}
222 	priv->bank = b;
223 }
224 
225 /*
226  * Register access routines through the SPI bus.
227  * Every register access comes in two flavours:
228  * - nolock_xxx: caller needs to invoke mutex_lock, usually to access
229  *   atomically more than one register
230  * - locked_xxx: caller doesn't need to invoke mutex_lock, single access
231  *
232  * Some registers can be accessed through the bit field clear and
233  * bit field set to avoid a read modify write cycle.
234  */
235 
236 /*
237  * Register bit field Set
238  */
239 static void nolock_reg_bfset(struct enc28j60_net *priv, u8 addr, u8 mask)
240 {
241 	enc28j60_set_bank(priv, addr);
242 	spi_write_op(priv, ENC28J60_BIT_FIELD_SET, addr, mask);
243 }
244 
245 static void locked_reg_bfset(struct enc28j60_net *priv, u8 addr, u8 mask)
246 {
247 	mutex_lock(&priv->lock);
248 	nolock_reg_bfset(priv, addr, mask);
249 	mutex_unlock(&priv->lock);
250 }
251 
252 /*
253  * Register bit field Clear
254  */
255 static void nolock_reg_bfclr(struct enc28j60_net *priv, u8 addr, u8 mask)
256 {
257 	enc28j60_set_bank(priv, addr);
258 	spi_write_op(priv, ENC28J60_BIT_FIELD_CLR, addr, mask);
259 }
260 
261 static void locked_reg_bfclr(struct enc28j60_net *priv, u8 addr, u8 mask)
262 {
263 	mutex_lock(&priv->lock);
264 	nolock_reg_bfclr(priv, addr, mask);
265 	mutex_unlock(&priv->lock);
266 }
267 
268 /*
269  * Register byte read
270  */
271 static int nolock_regb_read(struct enc28j60_net *priv, u8 address)
272 {
273 	enc28j60_set_bank(priv, address);
274 	return spi_read_op(priv, ENC28J60_READ_CTRL_REG, address);
275 }
276 
277 static int locked_regb_read(struct enc28j60_net *priv, u8 address)
278 {
279 	int ret;
280 
281 	mutex_lock(&priv->lock);
282 	ret = nolock_regb_read(priv, address);
283 	mutex_unlock(&priv->lock);
284 
285 	return ret;
286 }
287 
288 /*
289  * Register word read
290  */
291 static int nolock_regw_read(struct enc28j60_net *priv, u8 address)
292 {
293 	int rl, rh;
294 
295 	enc28j60_set_bank(priv, address);
296 	rl = spi_read_op(priv, ENC28J60_READ_CTRL_REG, address);
297 	rh = spi_read_op(priv, ENC28J60_READ_CTRL_REG, address + 1);
298 
299 	return (rh << 8) | rl;
300 }
301 
302 static int locked_regw_read(struct enc28j60_net *priv, u8 address)
303 {
304 	int ret;
305 
306 	mutex_lock(&priv->lock);
307 	ret = nolock_regw_read(priv, address);
308 	mutex_unlock(&priv->lock);
309 
310 	return ret;
311 }
312 
313 /*
314  * Register byte write
315  */
316 static void nolock_regb_write(struct enc28j60_net *priv, u8 address, u8 data)
317 {
318 	enc28j60_set_bank(priv, address);
319 	spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, address, data);
320 }
321 
322 static void locked_regb_write(struct enc28j60_net *priv, u8 address, u8 data)
323 {
324 	mutex_lock(&priv->lock);
325 	nolock_regb_write(priv, address, data);
326 	mutex_unlock(&priv->lock);
327 }
328 
329 /*
330  * Register word write
331  */
332 static void nolock_regw_write(struct enc28j60_net *priv, u8 address, u16 data)
333 {
334 	enc28j60_set_bank(priv, address);
335 	spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, address, (u8) data);
336 	spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, address + 1,
337 		     (u8) (data >> 8));
338 }
339 
340 static void locked_regw_write(struct enc28j60_net *priv, u8 address, u16 data)
341 {
342 	mutex_lock(&priv->lock);
343 	nolock_regw_write(priv, address, data);
344 	mutex_unlock(&priv->lock);
345 }
346 
347 /*
348  * Buffer memory read
349  * Select the starting address and execute a SPI buffer read.
350  */
351 static void enc28j60_mem_read(struct enc28j60_net *priv, u16 addr, int len,
352 			      u8 *data)
353 {
354 	mutex_lock(&priv->lock);
355 	nolock_regw_write(priv, ERDPTL, addr);
356 #ifdef CONFIG_ENC28J60_WRITEVERIFY
357 	if (netif_msg_drv(priv)) {
358 		struct device *dev = &priv->spi->dev;
359 		u16 reg;
360 
361 		reg = nolock_regw_read(priv, ERDPTL);
362 		if (reg != addr)
363 			dev_printk(KERN_DEBUG, dev,
364 				   "%s() error writing ERDPT (0x%04x - 0x%04x)\n",
365 				   __func__, reg, addr);
366 	}
367 #endif
368 	spi_read_buf(priv, len, data);
369 	mutex_unlock(&priv->lock);
370 }
371 
372 /*
373  * Write packet to enc28j60 TX buffer memory
374  */
375 static void
376 enc28j60_packet_write(struct enc28j60_net *priv, int len, const u8 *data)
377 {
378 	struct device *dev = &priv->spi->dev;
379 
380 	mutex_lock(&priv->lock);
381 	/* Set the write pointer to start of transmit buffer area */
382 	nolock_regw_write(priv, EWRPTL, TXSTART_INIT);
383 #ifdef CONFIG_ENC28J60_WRITEVERIFY
384 	if (netif_msg_drv(priv)) {
385 		u16 reg;
386 		reg = nolock_regw_read(priv, EWRPTL);
387 		if (reg != TXSTART_INIT)
388 			dev_printk(KERN_DEBUG, dev,
389 				   "%s() ERWPT:0x%04x != 0x%04x\n",
390 				   __func__, reg, TXSTART_INIT);
391 	}
392 #endif
393 	/* Set the TXND pointer to correspond to the packet size given */
394 	nolock_regw_write(priv, ETXNDL, TXSTART_INIT + len);
395 	/* write per-packet control byte */
396 	spi_write_op(priv, ENC28J60_WRITE_BUF_MEM, 0, 0x00);
397 	if (netif_msg_hw(priv))
398 		dev_printk(KERN_DEBUG, dev,
399 			   "%s() after control byte ERWPT:0x%04x\n",
400 			   __func__, nolock_regw_read(priv, EWRPTL));
401 	/* copy the packet into the transmit buffer */
402 	spi_write_buf(priv, len, data);
403 	if (netif_msg_hw(priv))
404 		dev_printk(KERN_DEBUG, dev,
405 			   "%s() after write packet ERWPT:0x%04x, len=%d\n",
406 			   __func__, nolock_regw_read(priv, EWRPTL), len);
407 	mutex_unlock(&priv->lock);
408 }
409 
410 static int poll_ready(struct enc28j60_net *priv, u8 reg, u8 mask, u8 val)
411 {
412 	struct device *dev = &priv->spi->dev;
413 	unsigned long timeout = jiffies + msecs_to_jiffies(20);
414 
415 	/* 20 msec timeout read */
416 	while ((nolock_regb_read(priv, reg) & mask) != val) {
417 		if (time_after(jiffies, timeout)) {
418 			if (netif_msg_drv(priv))
419 				dev_dbg(dev, "reg %02x ready timeout!\n", reg);
420 			return -ETIMEDOUT;
421 		}
422 		cpu_relax();
423 	}
424 	return 0;
425 }
426 
427 /*
428  * Wait until the PHY operation is complete.
429  */
430 static int wait_phy_ready(struct enc28j60_net *priv)
431 {
432 	return poll_ready(priv, MISTAT, MISTAT_BUSY, 0) ? 0 : 1;
433 }
434 
435 /*
436  * PHY register read
437  * PHY registers are not accessed directly, but through the MII.
438  */
439 static u16 enc28j60_phy_read(struct enc28j60_net *priv, u8 address)
440 {
441 	u16 ret;
442 
443 	mutex_lock(&priv->lock);
444 	/* set the PHY register address */
445 	nolock_regb_write(priv, MIREGADR, address);
446 	/* start the register read operation */
447 	nolock_regb_write(priv, MICMD, MICMD_MIIRD);
448 	/* wait until the PHY read completes */
449 	wait_phy_ready(priv);
450 	/* quit reading */
451 	nolock_regb_write(priv, MICMD, 0x00);
452 	/* return the data */
453 	ret = nolock_regw_read(priv, MIRDL);
454 	mutex_unlock(&priv->lock);
455 
456 	return ret;
457 }
458 
459 static int enc28j60_phy_write(struct enc28j60_net *priv, u8 address, u16 data)
460 {
461 	int ret;
462 
463 	mutex_lock(&priv->lock);
464 	/* set the PHY register address */
465 	nolock_regb_write(priv, MIREGADR, address);
466 	/* write the PHY data */
467 	nolock_regw_write(priv, MIWRL, data);
468 	/* wait until the PHY write completes and return */
469 	ret = wait_phy_ready(priv);
470 	mutex_unlock(&priv->lock);
471 
472 	return ret;
473 }
474 
475 /*
476  * Program the hardware MAC address from dev->dev_addr.
477  */
478 static int enc28j60_set_hw_macaddr(struct net_device *ndev)
479 {
480 	int ret;
481 	struct enc28j60_net *priv = netdev_priv(ndev);
482 	struct device *dev = &priv->spi->dev;
483 
484 	mutex_lock(&priv->lock);
485 	if (!priv->hw_enable) {
486 		if (netif_msg_drv(priv))
487 			dev_info(dev, "%s: Setting MAC address to %pM\n",
488 				 ndev->name, ndev->dev_addr);
489 		/* NOTE: MAC address in ENC28J60 is byte-backward */
490 		nolock_regb_write(priv, MAADR5, ndev->dev_addr[0]);
491 		nolock_regb_write(priv, MAADR4, ndev->dev_addr[1]);
492 		nolock_regb_write(priv, MAADR3, ndev->dev_addr[2]);
493 		nolock_regb_write(priv, MAADR2, ndev->dev_addr[3]);
494 		nolock_regb_write(priv, MAADR1, ndev->dev_addr[4]);
495 		nolock_regb_write(priv, MAADR0, ndev->dev_addr[5]);
496 		ret = 0;
497 	} else {
498 		if (netif_msg_drv(priv))
499 			dev_printk(KERN_DEBUG, dev,
500 				   "%s() Hardware must be disabled to set Mac address\n",
501 				   __func__);
502 		ret = -EBUSY;
503 	}
504 	mutex_unlock(&priv->lock);
505 	return ret;
506 }
507 
508 /*
509  * Store the new hardware address in dev->dev_addr, and update the MAC.
510  */
511 static int enc28j60_set_mac_address(struct net_device *dev, void *addr)
512 {
513 	struct sockaddr *address = addr;
514 
515 	if (netif_running(dev))
516 		return -EBUSY;
517 	if (!is_valid_ether_addr(address->sa_data))
518 		return -EADDRNOTAVAIL;
519 
520 	eth_hw_addr_set(dev, address->sa_data);
521 	return enc28j60_set_hw_macaddr(dev);
522 }
523 
524 /*
525  * Debug routine to dump useful register contents
526  */
527 static void enc28j60_dump_regs(struct enc28j60_net *priv, const char *msg)
528 {
529 	struct device *dev = &priv->spi->dev;
530 
531 	mutex_lock(&priv->lock);
532 	dev_printk(KERN_DEBUG, dev,
533 		   " %s\n"
534 		   "HwRevID: 0x%02x\n"
535 		   "Cntrl: ECON1 ECON2 ESTAT  EIR  EIE\n"
536 		   "       0x%02x  0x%02x  0x%02x  0x%02x  0x%02x\n"
537 		   "MAC  : MACON1 MACON3 MACON4\n"
538 		   "       0x%02x   0x%02x   0x%02x\n"
539 		   "Rx   : ERXST  ERXND  ERXWRPT ERXRDPT ERXFCON EPKTCNT MAMXFL\n"
540 		   "       0x%04x 0x%04x 0x%04x  0x%04x  "
541 		   "0x%02x    0x%02x    0x%04x\n"
542 		   "Tx   : ETXST  ETXND  MACLCON1 MACLCON2 MAPHSUP\n"
543 		   "       0x%04x 0x%04x 0x%02x     0x%02x     0x%02x\n",
544 		   msg, nolock_regb_read(priv, EREVID),
545 		   nolock_regb_read(priv, ECON1), nolock_regb_read(priv, ECON2),
546 		   nolock_regb_read(priv, ESTAT), nolock_regb_read(priv, EIR),
547 		   nolock_regb_read(priv, EIE), nolock_regb_read(priv, MACON1),
548 		   nolock_regb_read(priv, MACON3), nolock_regb_read(priv, MACON4),
549 		   nolock_regw_read(priv, ERXSTL), nolock_regw_read(priv, ERXNDL),
550 		   nolock_regw_read(priv, ERXWRPTL),
551 		   nolock_regw_read(priv, ERXRDPTL),
552 		   nolock_regb_read(priv, ERXFCON),
553 		   nolock_regb_read(priv, EPKTCNT),
554 		   nolock_regw_read(priv, MAMXFLL), nolock_regw_read(priv, ETXSTL),
555 		   nolock_regw_read(priv, ETXNDL),
556 		   nolock_regb_read(priv, MACLCON1),
557 		   nolock_regb_read(priv, MACLCON2),
558 		   nolock_regb_read(priv, MAPHSUP));
559 	mutex_unlock(&priv->lock);
560 }
561 
562 /*
563  * ERXRDPT need to be set always at odd addresses, refer to errata datasheet
564  */
565 static u16 erxrdpt_workaround(u16 next_packet_ptr, u16 start, u16 end)
566 {
567 	u16 erxrdpt;
568 
569 	if ((next_packet_ptr - 1 < start) || (next_packet_ptr - 1 > end))
570 		erxrdpt = end;
571 	else
572 		erxrdpt = next_packet_ptr - 1;
573 
574 	return erxrdpt;
575 }
576 
577 /*
578  * Calculate wrap around when reading beyond the end of the RX buffer
579  */
580 static u16 rx_packet_start(u16 ptr)
581 {
582 	if (ptr + RSV_SIZE > RXEND_INIT)
583 		return (ptr + RSV_SIZE) - (RXEND_INIT - RXSTART_INIT + 1);
584 	else
585 		return ptr + RSV_SIZE;
586 }
587 
588 static void nolock_rxfifo_init(struct enc28j60_net *priv, u16 start, u16 end)
589 {
590 	struct device *dev = &priv->spi->dev;
591 	u16 erxrdpt;
592 
593 	if (start > 0x1FFF || end > 0x1FFF || start > end) {
594 		if (netif_msg_drv(priv))
595 			dev_err(dev, "%s(%d, %d) RXFIFO bad parameters!\n",
596 				__func__, start, end);
597 		return;
598 	}
599 	/* set receive buffer start + end */
600 	priv->next_pk_ptr = start;
601 	nolock_regw_write(priv, ERXSTL, start);
602 	erxrdpt = erxrdpt_workaround(priv->next_pk_ptr, start, end);
603 	nolock_regw_write(priv, ERXRDPTL, erxrdpt);
604 	nolock_regw_write(priv, ERXNDL, end);
605 }
606 
607 static void nolock_txfifo_init(struct enc28j60_net *priv, u16 start, u16 end)
608 {
609 	struct device *dev = &priv->spi->dev;
610 
611 	if (start > 0x1FFF || end > 0x1FFF || start > end) {
612 		if (netif_msg_drv(priv))
613 			dev_err(dev, "%s(%d, %d) TXFIFO bad parameters!\n",
614 				__func__, start, end);
615 		return;
616 	}
617 	/* set transmit buffer start + end */
618 	nolock_regw_write(priv, ETXSTL, start);
619 	nolock_regw_write(priv, ETXNDL, end);
620 }
621 
622 /*
623  * Low power mode shrinks power consumption about 100x, so we'd like
624  * the chip to be in that mode whenever it's inactive. (However, we
625  * can't stay in low power mode during suspend with WOL active.)
626  */
627 static void enc28j60_lowpower(struct enc28j60_net *priv, bool is_low)
628 {
629 	struct device *dev = &priv->spi->dev;
630 
631 	if (netif_msg_drv(priv))
632 		dev_dbg(dev, "%s power...\n", is_low ? "low" : "high");
633 
634 	mutex_lock(&priv->lock);
635 	if (is_low) {
636 		nolock_reg_bfclr(priv, ECON1, ECON1_RXEN);
637 		poll_ready(priv, ESTAT, ESTAT_RXBUSY, 0);
638 		poll_ready(priv, ECON1, ECON1_TXRTS, 0);
639 		/* ECON2_VRPS was set during initialization */
640 		nolock_reg_bfset(priv, ECON2, ECON2_PWRSV);
641 	} else {
642 		nolock_reg_bfclr(priv, ECON2, ECON2_PWRSV);
643 		poll_ready(priv, ESTAT, ESTAT_CLKRDY, ESTAT_CLKRDY);
644 		/* caller sets ECON1_RXEN */
645 	}
646 	mutex_unlock(&priv->lock);
647 }
648 
649 static int enc28j60_hw_init(struct enc28j60_net *priv)
650 {
651 	struct device *dev = &priv->spi->dev;
652 	u8 reg;
653 
654 	if (netif_msg_drv(priv))
655 		dev_printk(KERN_DEBUG, dev, "%s() - %s\n", __func__,
656 			   priv->full_duplex ? "FullDuplex" : "HalfDuplex");
657 
658 	mutex_lock(&priv->lock);
659 	/* first reset the chip */
660 	enc28j60_soft_reset(priv);
661 	/* Clear ECON1 */
662 	spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, ECON1, 0x00);
663 	priv->bank = 0;
664 	priv->hw_enable = false;
665 	priv->tx_retry_count = 0;
666 	priv->max_pk_counter = 0;
667 	priv->rxfilter = RXFILTER_NORMAL;
668 	/* enable address auto increment and voltage regulator powersave */
669 	nolock_regb_write(priv, ECON2, ECON2_AUTOINC | ECON2_VRPS);
670 
671 	nolock_rxfifo_init(priv, RXSTART_INIT, RXEND_INIT);
672 	nolock_txfifo_init(priv, TXSTART_INIT, TXEND_INIT);
673 	mutex_unlock(&priv->lock);
674 
675 	/*
676 	 * Check the RevID.
677 	 * If it's 0x00 or 0xFF probably the enc28j60 is not mounted or
678 	 * damaged.
679 	 */
680 	reg = locked_regb_read(priv, EREVID);
681 	if (netif_msg_drv(priv))
682 		dev_info(dev, "chip RevID: 0x%02x\n", reg);
683 	if (reg == 0x00 || reg == 0xff) {
684 		if (netif_msg_drv(priv))
685 			dev_printk(KERN_DEBUG, dev, "%s() Invalid RevId %d\n",
686 				   __func__, reg);
687 		return 0;
688 	}
689 
690 	/* default filter mode: (unicast OR broadcast) AND crc valid */
691 	locked_regb_write(priv, ERXFCON,
692 			    ERXFCON_UCEN | ERXFCON_CRCEN | ERXFCON_BCEN);
693 
694 	/* enable MAC receive */
695 	locked_regb_write(priv, MACON1,
696 			    MACON1_MARXEN | MACON1_TXPAUS | MACON1_RXPAUS);
697 	/* enable automatic padding and CRC operations */
698 	if (priv->full_duplex) {
699 		locked_regb_write(priv, MACON3,
700 				    MACON3_PADCFG0 | MACON3_TXCRCEN |
701 				    MACON3_FRMLNEN | MACON3_FULDPX);
702 		/* set inter-frame gap (non-back-to-back) */
703 		locked_regb_write(priv, MAIPGL, 0x12);
704 		/* set inter-frame gap (back-to-back) */
705 		locked_regb_write(priv, MABBIPG, 0x15);
706 	} else {
707 		locked_regb_write(priv, MACON3,
708 				    MACON3_PADCFG0 | MACON3_TXCRCEN |
709 				    MACON3_FRMLNEN);
710 		locked_regb_write(priv, MACON4, 1 << 6);	/* DEFER bit */
711 		/* set inter-frame gap (non-back-to-back) */
712 		locked_regw_write(priv, MAIPGL, 0x0C12);
713 		/* set inter-frame gap (back-to-back) */
714 		locked_regb_write(priv, MABBIPG, 0x12);
715 	}
716 	/*
717 	 * MACLCON1 (default)
718 	 * MACLCON2 (default)
719 	 * Set the maximum packet size which the controller will accept.
720 	 */
721 	locked_regw_write(priv, MAMXFLL, MAX_FRAMELEN);
722 
723 	/* Configure LEDs */
724 	if (!enc28j60_phy_write(priv, PHLCON, ENC28J60_LAMPS_MODE))
725 		return 0;
726 
727 	if (priv->full_duplex) {
728 		if (!enc28j60_phy_write(priv, PHCON1, PHCON1_PDPXMD))
729 			return 0;
730 		if (!enc28j60_phy_write(priv, PHCON2, 0x00))
731 			return 0;
732 	} else {
733 		if (!enc28j60_phy_write(priv, PHCON1, 0x00))
734 			return 0;
735 		if (!enc28j60_phy_write(priv, PHCON2, PHCON2_HDLDIS))
736 			return 0;
737 	}
738 	if (netif_msg_hw(priv))
739 		enc28j60_dump_regs(priv, "Hw initialized.");
740 
741 	return 1;
742 }
743 
744 static void enc28j60_hw_enable(struct enc28j60_net *priv)
745 {
746 	struct device *dev = &priv->spi->dev;
747 
748 	/* enable interrupts */
749 	if (netif_msg_hw(priv))
750 		dev_printk(KERN_DEBUG, dev, "%s() enabling interrupts.\n",
751 			   __func__);
752 
753 	enc28j60_phy_write(priv, PHIE, PHIE_PGEIE | PHIE_PLNKIE);
754 
755 	mutex_lock(&priv->lock);
756 	nolock_reg_bfclr(priv, EIR, EIR_DMAIF | EIR_LINKIF |
757 			 EIR_TXIF | EIR_TXERIF | EIR_RXERIF | EIR_PKTIF);
758 	nolock_regb_write(priv, EIE, EIE_INTIE | EIE_PKTIE | EIE_LINKIE |
759 			  EIE_TXIE | EIE_TXERIE | EIE_RXERIE);
760 
761 	/* enable receive logic */
762 	nolock_reg_bfset(priv, ECON1, ECON1_RXEN);
763 	priv->hw_enable = true;
764 	mutex_unlock(&priv->lock);
765 }
766 
767 static void enc28j60_hw_disable(struct enc28j60_net *priv)
768 {
769 	mutex_lock(&priv->lock);
770 	/* disable interrupts and packet reception */
771 	nolock_regb_write(priv, EIE, 0x00);
772 	nolock_reg_bfclr(priv, ECON1, ECON1_RXEN);
773 	priv->hw_enable = false;
774 	mutex_unlock(&priv->lock);
775 }
776 
777 static int
778 enc28j60_setlink(struct net_device *ndev, u8 autoneg, u16 speed, u8 duplex)
779 {
780 	struct enc28j60_net *priv = netdev_priv(ndev);
781 	int ret = 0;
782 
783 	if (!priv->hw_enable) {
784 		/* link is in low power mode now; duplex setting
785 		 * will take effect on next enc28j60_hw_init().
786 		 */
787 		if (autoneg == AUTONEG_DISABLE && speed == SPEED_10)
788 			priv->full_duplex = (duplex == DUPLEX_FULL);
789 		else {
790 			if (netif_msg_link(priv))
791 				netdev_warn(ndev, "unsupported link setting\n");
792 			ret = -EOPNOTSUPP;
793 		}
794 	} else {
795 		if (netif_msg_link(priv))
796 			netdev_warn(ndev, "Warning: hw must be disabled to set link mode\n");
797 		ret = -EBUSY;
798 	}
799 	return ret;
800 }
801 
802 /*
803  * Read the Transmit Status Vector
804  */
805 static void enc28j60_read_tsv(struct enc28j60_net *priv, u8 tsv[TSV_SIZE])
806 {
807 	struct device *dev = &priv->spi->dev;
808 	int endptr;
809 
810 	endptr = locked_regw_read(priv, ETXNDL);
811 	if (netif_msg_hw(priv))
812 		dev_printk(KERN_DEBUG, dev, "reading TSV at addr:0x%04x\n",
813 			   endptr + 1);
814 	enc28j60_mem_read(priv, endptr + 1, TSV_SIZE, tsv);
815 }
816 
817 static void enc28j60_dump_tsv(struct enc28j60_net *priv, const char *msg,
818 			      u8 tsv[TSV_SIZE])
819 {
820 	struct device *dev = &priv->spi->dev;
821 	u16 tmp1, tmp2;
822 
823 	dev_printk(KERN_DEBUG, dev, "%s - TSV:\n", msg);
824 	tmp1 = tsv[1];
825 	tmp1 <<= 8;
826 	tmp1 |= tsv[0];
827 
828 	tmp2 = tsv[5];
829 	tmp2 <<= 8;
830 	tmp2 |= tsv[4];
831 
832 	dev_printk(KERN_DEBUG, dev,
833 		   "ByteCount: %d, CollisionCount: %d, TotByteOnWire: %d\n",
834 		   tmp1, tsv[2] & 0x0f, tmp2);
835 	dev_printk(KERN_DEBUG, dev,
836 		   "TxDone: %d, CRCErr:%d, LenChkErr: %d, LenOutOfRange: %d\n",
837 		   TSV_GETBIT(tsv, TSV_TXDONE),
838 		   TSV_GETBIT(tsv, TSV_TXCRCERROR),
839 		   TSV_GETBIT(tsv, TSV_TXLENCHKERROR),
840 		   TSV_GETBIT(tsv, TSV_TXLENOUTOFRANGE));
841 	dev_printk(KERN_DEBUG, dev,
842 		   "Multicast: %d, Broadcast: %d, PacketDefer: %d, ExDefer: %d\n",
843 		   TSV_GETBIT(tsv, TSV_TXMULTICAST),
844 		   TSV_GETBIT(tsv, TSV_TXBROADCAST),
845 		   TSV_GETBIT(tsv, TSV_TXPACKETDEFER),
846 		   TSV_GETBIT(tsv, TSV_TXEXDEFER));
847 	dev_printk(KERN_DEBUG, dev,
848 		   "ExCollision: %d, LateCollision: %d, Giant: %d, Underrun: %d\n",
849 		   TSV_GETBIT(tsv, TSV_TXEXCOLLISION),
850 		   TSV_GETBIT(tsv, TSV_TXLATECOLLISION),
851 		   TSV_GETBIT(tsv, TSV_TXGIANT), TSV_GETBIT(tsv, TSV_TXUNDERRUN));
852 	dev_printk(KERN_DEBUG, dev,
853 		   "ControlFrame: %d, PauseFrame: %d, BackPressApp: %d, VLanTagFrame: %d\n",
854 		   TSV_GETBIT(tsv, TSV_TXCONTROLFRAME),
855 		   TSV_GETBIT(tsv, TSV_TXPAUSEFRAME),
856 		   TSV_GETBIT(tsv, TSV_BACKPRESSUREAPP),
857 		   TSV_GETBIT(tsv, TSV_TXVLANTAGFRAME));
858 }
859 
860 /*
861  * Receive Status vector
862  */
863 static void enc28j60_dump_rsv(struct enc28j60_net *priv, const char *msg,
864 			      u16 pk_ptr, int len, u16 sts)
865 {
866 	struct device *dev = &priv->spi->dev;
867 
868 	dev_printk(KERN_DEBUG, dev, "%s - NextPk: 0x%04x - RSV:\n", msg, pk_ptr);
869 	dev_printk(KERN_DEBUG, dev, "ByteCount: %d, DribbleNibble: %d\n",
870 		   len, RSV_GETBIT(sts, RSV_DRIBBLENIBBLE));
871 	dev_printk(KERN_DEBUG, dev,
872 		   "RxOK: %d, CRCErr:%d, LenChkErr: %d, LenOutOfRange: %d\n",
873 		   RSV_GETBIT(sts, RSV_RXOK),
874 		   RSV_GETBIT(sts, RSV_CRCERROR),
875 		   RSV_GETBIT(sts, RSV_LENCHECKERR),
876 		   RSV_GETBIT(sts, RSV_LENOUTOFRANGE));
877 	dev_printk(KERN_DEBUG, dev,
878 		   "Multicast: %d, Broadcast: %d, LongDropEvent: %d, CarrierEvent: %d\n",
879 		   RSV_GETBIT(sts, RSV_RXMULTICAST),
880 		   RSV_GETBIT(sts, RSV_RXBROADCAST),
881 		   RSV_GETBIT(sts, RSV_RXLONGEVDROPEV),
882 		   RSV_GETBIT(sts, RSV_CARRIEREV));
883 	dev_printk(KERN_DEBUG, dev,
884 		   "ControlFrame: %d, PauseFrame: %d, UnknownOp: %d, VLanTagFrame: %d\n",
885 		   RSV_GETBIT(sts, RSV_RXCONTROLFRAME),
886 		   RSV_GETBIT(sts, RSV_RXPAUSEFRAME),
887 		   RSV_GETBIT(sts, RSV_RXUNKNOWNOPCODE),
888 		   RSV_GETBIT(sts, RSV_RXTYPEVLAN));
889 }
890 
891 static void dump_packet(const char *msg, int len, const char *data)
892 {
893 	printk(KERN_DEBUG DRV_NAME ": %s - packet len:%d\n", msg, len);
894 	print_hex_dump(KERN_DEBUG, "pk data: ", DUMP_PREFIX_OFFSET, 16, 1,
895 			data, len, true);
896 }
897 
898 /*
899  * Hardware receive function.
900  * Read the buffer memory, update the FIFO pointer to free the buffer,
901  * check the status vector and decrement the packet counter.
902  */
903 static void enc28j60_hw_rx(struct net_device *ndev)
904 {
905 	struct enc28j60_net *priv = netdev_priv(ndev);
906 	struct device *dev = &priv->spi->dev;
907 	struct sk_buff *skb = NULL;
908 	u16 erxrdpt, next_packet, rxstat;
909 	u8 rsv[RSV_SIZE];
910 	int len;
911 
912 	if (netif_msg_rx_status(priv))
913 		netdev_printk(KERN_DEBUG, ndev, "RX pk_addr:0x%04x\n",
914 			      priv->next_pk_ptr);
915 
916 	if (unlikely(priv->next_pk_ptr > RXEND_INIT)) {
917 		if (netif_msg_rx_err(priv))
918 			netdev_err(ndev, "%s() Invalid packet address!! 0x%04x\n",
919 				   __func__, priv->next_pk_ptr);
920 		/* packet address corrupted: reset RX logic */
921 		mutex_lock(&priv->lock);
922 		nolock_reg_bfclr(priv, ECON1, ECON1_RXEN);
923 		nolock_reg_bfset(priv, ECON1, ECON1_RXRST);
924 		nolock_reg_bfclr(priv, ECON1, ECON1_RXRST);
925 		nolock_rxfifo_init(priv, RXSTART_INIT, RXEND_INIT);
926 		nolock_reg_bfclr(priv, EIR, EIR_RXERIF);
927 		nolock_reg_bfset(priv, ECON1, ECON1_RXEN);
928 		mutex_unlock(&priv->lock);
929 		ndev->stats.rx_errors++;
930 		return;
931 	}
932 	/* Read next packet pointer and rx status vector */
933 	enc28j60_mem_read(priv, priv->next_pk_ptr, sizeof(rsv), rsv);
934 
935 	next_packet = rsv[1];
936 	next_packet <<= 8;
937 	next_packet |= rsv[0];
938 
939 	len = rsv[3];
940 	len <<= 8;
941 	len |= rsv[2];
942 
943 	rxstat = rsv[5];
944 	rxstat <<= 8;
945 	rxstat |= rsv[4];
946 
947 	if (netif_msg_rx_status(priv))
948 		enc28j60_dump_rsv(priv, __func__, next_packet, len, rxstat);
949 
950 	if (!RSV_GETBIT(rxstat, RSV_RXOK) || len > MAX_FRAMELEN) {
951 		if (netif_msg_rx_err(priv))
952 			netdev_err(ndev, "Rx Error (%04x)\n", rxstat);
953 		ndev->stats.rx_errors++;
954 		if (RSV_GETBIT(rxstat, RSV_CRCERROR))
955 			ndev->stats.rx_crc_errors++;
956 		if (RSV_GETBIT(rxstat, RSV_LENCHECKERR))
957 			ndev->stats.rx_frame_errors++;
958 		if (len > MAX_FRAMELEN)
959 			ndev->stats.rx_over_errors++;
960 	} else {
961 		skb = netdev_alloc_skb(ndev, len + NET_IP_ALIGN);
962 		if (!skb) {
963 			if (netif_msg_rx_err(priv))
964 				netdev_err(ndev, "out of memory for Rx'd frame\n");
965 			ndev->stats.rx_dropped++;
966 		} else {
967 			skb_reserve(skb, NET_IP_ALIGN);
968 			/* copy the packet from the receive buffer */
969 			enc28j60_mem_read(priv,
970 				rx_packet_start(priv->next_pk_ptr),
971 				len, skb_put(skb, len));
972 			if (netif_msg_pktdata(priv))
973 				dump_packet(__func__, skb->len, skb->data);
974 			skb->protocol = eth_type_trans(skb, ndev);
975 			/* update statistics */
976 			ndev->stats.rx_packets++;
977 			ndev->stats.rx_bytes += len;
978 			netif_rx(skb);
979 		}
980 	}
981 	/*
982 	 * Move the RX read pointer to the start of the next
983 	 * received packet.
984 	 * This frees the memory we just read out.
985 	 */
986 	erxrdpt = erxrdpt_workaround(next_packet, RXSTART_INIT, RXEND_INIT);
987 	if (netif_msg_hw(priv))
988 		dev_printk(KERN_DEBUG, dev, "%s() ERXRDPT:0x%04x\n",
989 			   __func__, erxrdpt);
990 
991 	mutex_lock(&priv->lock);
992 	nolock_regw_write(priv, ERXRDPTL, erxrdpt);
993 #ifdef CONFIG_ENC28J60_WRITEVERIFY
994 	if (netif_msg_drv(priv)) {
995 		u16 reg;
996 		reg = nolock_regw_read(priv, ERXRDPTL);
997 		if (reg != erxrdpt)
998 			dev_printk(KERN_DEBUG, dev,
999 				   "%s() ERXRDPT verify error (0x%04x - 0x%04x)\n",
1000 				   __func__, reg, erxrdpt);
1001 	}
1002 #endif
1003 	priv->next_pk_ptr = next_packet;
1004 	/* we are done with this packet, decrement the packet counter */
1005 	nolock_reg_bfset(priv, ECON2, ECON2_PKTDEC);
1006 	mutex_unlock(&priv->lock);
1007 }
1008 
1009 /*
1010  * Calculate free space in RxFIFO
1011  */
1012 static int enc28j60_get_free_rxfifo(struct enc28j60_net *priv)
1013 {
1014 	struct net_device *ndev = priv->netdev;
1015 	int epkcnt, erxst, erxnd, erxwr, erxrd;
1016 	int free_space;
1017 
1018 	mutex_lock(&priv->lock);
1019 	epkcnt = nolock_regb_read(priv, EPKTCNT);
1020 	if (epkcnt >= 255)
1021 		free_space = -1;
1022 	else {
1023 		erxst = nolock_regw_read(priv, ERXSTL);
1024 		erxnd = nolock_regw_read(priv, ERXNDL);
1025 		erxwr = nolock_regw_read(priv, ERXWRPTL);
1026 		erxrd = nolock_regw_read(priv, ERXRDPTL);
1027 
1028 		if (erxwr > erxrd)
1029 			free_space = (erxnd - erxst) - (erxwr - erxrd);
1030 		else if (erxwr == erxrd)
1031 			free_space = (erxnd - erxst);
1032 		else
1033 			free_space = erxrd - erxwr - 1;
1034 	}
1035 	mutex_unlock(&priv->lock);
1036 	if (netif_msg_rx_status(priv))
1037 		netdev_printk(KERN_DEBUG, ndev, "%s() free_space = %d\n",
1038 			      __func__, free_space);
1039 	return free_space;
1040 }
1041 
1042 /*
1043  * Access the PHY to determine link status
1044  */
1045 static void enc28j60_check_link_status(struct net_device *ndev)
1046 {
1047 	struct enc28j60_net *priv = netdev_priv(ndev);
1048 	struct device *dev = &priv->spi->dev;
1049 	u16 reg;
1050 	int duplex;
1051 
1052 	reg = enc28j60_phy_read(priv, PHSTAT2);
1053 	if (netif_msg_hw(priv))
1054 		dev_printk(KERN_DEBUG, dev,
1055 			   "%s() PHSTAT1: %04x, PHSTAT2: %04x\n", __func__,
1056 			   enc28j60_phy_read(priv, PHSTAT1), reg);
1057 	duplex = reg & PHSTAT2_DPXSTAT;
1058 
1059 	if (reg & PHSTAT2_LSTAT) {
1060 		netif_carrier_on(ndev);
1061 		if (netif_msg_ifup(priv))
1062 			netdev_info(ndev, "link up - %s\n",
1063 				    duplex ? "Full duplex" : "Half duplex");
1064 	} else {
1065 		if (netif_msg_ifdown(priv))
1066 			netdev_info(ndev, "link down\n");
1067 		netif_carrier_off(ndev);
1068 	}
1069 }
1070 
1071 static void enc28j60_tx_clear(struct net_device *ndev, bool err)
1072 {
1073 	struct enc28j60_net *priv = netdev_priv(ndev);
1074 
1075 	if (err)
1076 		ndev->stats.tx_errors++;
1077 	else
1078 		ndev->stats.tx_packets++;
1079 
1080 	if (priv->tx_skb) {
1081 		if (!err)
1082 			ndev->stats.tx_bytes += priv->tx_skb->len;
1083 		dev_kfree_skb(priv->tx_skb);
1084 		priv->tx_skb = NULL;
1085 	}
1086 	locked_reg_bfclr(priv, ECON1, ECON1_TXRTS);
1087 	netif_wake_queue(ndev);
1088 }
1089 
1090 /*
1091  * RX handler
1092  * Ignore PKTIF because is unreliable! (Look at the errata datasheet)
1093  * Check EPKTCNT is the suggested workaround.
1094  * We don't need to clear interrupt flag, automatically done when
1095  * enc28j60_hw_rx() decrements the packet counter.
1096  * Returns how many packet processed.
1097  */
1098 static int enc28j60_rx_interrupt(struct net_device *ndev)
1099 {
1100 	struct enc28j60_net *priv = netdev_priv(ndev);
1101 	int pk_counter, ret;
1102 
1103 	pk_counter = locked_regb_read(priv, EPKTCNT);
1104 	if (pk_counter && netif_msg_intr(priv))
1105 		netdev_printk(KERN_DEBUG, ndev, "intRX, pk_cnt: %d\n",
1106 			      pk_counter);
1107 	if (pk_counter > priv->max_pk_counter) {
1108 		/* update statistics */
1109 		priv->max_pk_counter = pk_counter;
1110 		if (netif_msg_rx_status(priv) && priv->max_pk_counter > 1)
1111 			netdev_printk(KERN_DEBUG, ndev, "RX max_pk_cnt: %d\n",
1112 				      priv->max_pk_counter);
1113 	}
1114 	ret = pk_counter;
1115 	while (pk_counter-- > 0)
1116 		enc28j60_hw_rx(ndev);
1117 
1118 	return ret;
1119 }
1120 
1121 static void enc28j60_irq_work_handler(struct work_struct *work)
1122 {
1123 	struct enc28j60_net *priv =
1124 		container_of(work, struct enc28j60_net, irq_work);
1125 	struct net_device *ndev = priv->netdev;
1126 	int intflags, loop;
1127 
1128 	/* disable further interrupts */
1129 	locked_reg_bfclr(priv, EIE, EIE_INTIE);
1130 
1131 	do {
1132 		loop = 0;
1133 		intflags = locked_regb_read(priv, EIR);
1134 		/* DMA interrupt handler (not currently used) */
1135 		if ((intflags & EIR_DMAIF) != 0) {
1136 			loop++;
1137 			if (netif_msg_intr(priv))
1138 				netdev_printk(KERN_DEBUG, ndev, "intDMA(%d)\n",
1139 					      loop);
1140 			locked_reg_bfclr(priv, EIR, EIR_DMAIF);
1141 		}
1142 		/* LINK changed handler */
1143 		if ((intflags & EIR_LINKIF) != 0) {
1144 			loop++;
1145 			if (netif_msg_intr(priv))
1146 				netdev_printk(KERN_DEBUG, ndev, "intLINK(%d)\n",
1147 					      loop);
1148 			enc28j60_check_link_status(ndev);
1149 			/* read PHIR to clear the flag */
1150 			enc28j60_phy_read(priv, PHIR);
1151 		}
1152 		/* TX complete handler */
1153 		if (((intflags & EIR_TXIF) != 0) &&
1154 		    ((intflags & EIR_TXERIF) == 0)) {
1155 			bool err = false;
1156 			loop++;
1157 			if (netif_msg_intr(priv))
1158 				netdev_printk(KERN_DEBUG, ndev, "intTX(%d)\n",
1159 					      loop);
1160 			priv->tx_retry_count = 0;
1161 			if (locked_regb_read(priv, ESTAT) & ESTAT_TXABRT) {
1162 				if (netif_msg_tx_err(priv))
1163 					netdev_err(ndev, "Tx Error (aborted)\n");
1164 				err = true;
1165 			}
1166 			if (netif_msg_tx_done(priv)) {
1167 				u8 tsv[TSV_SIZE];
1168 				enc28j60_read_tsv(priv, tsv);
1169 				enc28j60_dump_tsv(priv, "Tx Done", tsv);
1170 			}
1171 			enc28j60_tx_clear(ndev, err);
1172 			locked_reg_bfclr(priv, EIR, EIR_TXIF);
1173 		}
1174 		/* TX Error handler */
1175 		if ((intflags & EIR_TXERIF) != 0) {
1176 			u8 tsv[TSV_SIZE];
1177 
1178 			loop++;
1179 			if (netif_msg_intr(priv))
1180 				netdev_printk(KERN_DEBUG, ndev, "intTXErr(%d)\n",
1181 					      loop);
1182 			locked_reg_bfclr(priv, ECON1, ECON1_TXRTS);
1183 			enc28j60_read_tsv(priv, tsv);
1184 			if (netif_msg_tx_err(priv))
1185 				enc28j60_dump_tsv(priv, "Tx Error", tsv);
1186 			/* Reset TX logic */
1187 			mutex_lock(&priv->lock);
1188 			nolock_reg_bfset(priv, ECON1, ECON1_TXRST);
1189 			nolock_reg_bfclr(priv, ECON1, ECON1_TXRST);
1190 			nolock_txfifo_init(priv, TXSTART_INIT, TXEND_INIT);
1191 			mutex_unlock(&priv->lock);
1192 			/* Transmit Late collision check for retransmit */
1193 			if (TSV_GETBIT(tsv, TSV_TXLATECOLLISION)) {
1194 				if (netif_msg_tx_err(priv))
1195 					netdev_printk(KERN_DEBUG, ndev,
1196 						      "LateCollision TXErr (%d)\n",
1197 						      priv->tx_retry_count);
1198 				if (priv->tx_retry_count++ < MAX_TX_RETRYCOUNT)
1199 					locked_reg_bfset(priv, ECON1,
1200 							   ECON1_TXRTS);
1201 				else
1202 					enc28j60_tx_clear(ndev, true);
1203 			} else
1204 				enc28j60_tx_clear(ndev, true);
1205 			locked_reg_bfclr(priv, EIR, EIR_TXERIF | EIR_TXIF);
1206 		}
1207 		/* RX Error handler */
1208 		if ((intflags & EIR_RXERIF) != 0) {
1209 			loop++;
1210 			if (netif_msg_intr(priv))
1211 				netdev_printk(KERN_DEBUG, ndev, "intRXErr(%d)\n",
1212 					      loop);
1213 			/* Check free FIFO space to flag RX overrun */
1214 			if (enc28j60_get_free_rxfifo(priv) <= 0) {
1215 				if (netif_msg_rx_err(priv))
1216 					netdev_printk(KERN_DEBUG, ndev, "RX Overrun\n");
1217 				ndev->stats.rx_dropped++;
1218 			}
1219 			locked_reg_bfclr(priv, EIR, EIR_RXERIF);
1220 		}
1221 		/* RX handler */
1222 		if (enc28j60_rx_interrupt(ndev))
1223 			loop++;
1224 	} while (loop);
1225 
1226 	/* re-enable interrupts */
1227 	locked_reg_bfset(priv, EIE, EIE_INTIE);
1228 }
1229 
1230 /*
1231  * Hardware transmit function.
1232  * Fill the buffer memory and send the contents of the transmit buffer
1233  * onto the network
1234  */
1235 static void enc28j60_hw_tx(struct enc28j60_net *priv)
1236 {
1237 	struct net_device *ndev = priv->netdev;
1238 
1239 	BUG_ON(!priv->tx_skb);
1240 
1241 	if (netif_msg_tx_queued(priv))
1242 		netdev_printk(KERN_DEBUG, ndev, "Tx Packet Len:%d\n",
1243 			      priv->tx_skb->len);
1244 
1245 	if (netif_msg_pktdata(priv))
1246 		dump_packet(__func__,
1247 			    priv->tx_skb->len, priv->tx_skb->data);
1248 	enc28j60_packet_write(priv, priv->tx_skb->len, priv->tx_skb->data);
1249 
1250 #ifdef CONFIG_ENC28J60_WRITEVERIFY
1251 	/* readback and verify written data */
1252 	if (netif_msg_drv(priv)) {
1253 		struct device *dev = &priv->spi->dev;
1254 		int test_len, k;
1255 		u8 test_buf[64]; /* limit the test to the first 64 bytes */
1256 		int okflag;
1257 
1258 		test_len = priv->tx_skb->len;
1259 		if (test_len > sizeof(test_buf))
1260 			test_len = sizeof(test_buf);
1261 
1262 		/* + 1 to skip control byte */
1263 		enc28j60_mem_read(priv, TXSTART_INIT + 1, test_len, test_buf);
1264 		okflag = 1;
1265 		for (k = 0; k < test_len; k++) {
1266 			if (priv->tx_skb->data[k] != test_buf[k]) {
1267 				dev_printk(KERN_DEBUG, dev,
1268 					   "Error, %d location differ: 0x%02x-0x%02x\n",
1269 					   k, priv->tx_skb->data[k], test_buf[k]);
1270 				okflag = 0;
1271 			}
1272 		}
1273 		if (!okflag)
1274 			dev_printk(KERN_DEBUG, dev, "Tx write buffer, verify ERROR!\n");
1275 	}
1276 #endif
1277 	/* set TX request flag */
1278 	locked_reg_bfset(priv, ECON1, ECON1_TXRTS);
1279 }
1280 
1281 static netdev_tx_t enc28j60_send_packet(struct sk_buff *skb,
1282 					struct net_device *dev)
1283 {
1284 	struct enc28j60_net *priv = netdev_priv(dev);
1285 
1286 	/* If some error occurs while trying to transmit this
1287 	 * packet, you should return '1' from this function.
1288 	 * In such a case you _may not_ do anything to the
1289 	 * SKB, it is still owned by the network queueing
1290 	 * layer when an error is returned. This means you
1291 	 * may not modify any SKB fields, you may not free
1292 	 * the SKB, etc.
1293 	 */
1294 	netif_stop_queue(dev);
1295 
1296 	/* Remember the skb for deferred processing */
1297 	priv->tx_skb = skb;
1298 	schedule_work(&priv->tx_work);
1299 
1300 	return NETDEV_TX_OK;
1301 }
1302 
1303 static void enc28j60_tx_work_handler(struct work_struct *work)
1304 {
1305 	struct enc28j60_net *priv =
1306 		container_of(work, struct enc28j60_net, tx_work);
1307 
1308 	/* actual delivery of data */
1309 	enc28j60_hw_tx(priv);
1310 }
1311 
1312 static irqreturn_t enc28j60_irq(int irq, void *dev_id)
1313 {
1314 	struct enc28j60_net *priv = dev_id;
1315 
1316 	/*
1317 	 * Can't do anything in interrupt context because we need to
1318 	 * block (spi_sync() is blocking) so fire of the interrupt
1319 	 * handling workqueue.
1320 	 * Remember that we access enc28j60 registers through SPI bus
1321 	 * via spi_sync() call.
1322 	 */
1323 	schedule_work(&priv->irq_work);
1324 
1325 	return IRQ_HANDLED;
1326 }
1327 
1328 static void enc28j60_tx_timeout(struct net_device *ndev, unsigned int txqueue)
1329 {
1330 	struct enc28j60_net *priv = netdev_priv(ndev);
1331 
1332 	if (netif_msg_timer(priv))
1333 		netdev_err(ndev, "tx timeout\n");
1334 
1335 	ndev->stats.tx_errors++;
1336 	/* can't restart safely under softirq */
1337 	schedule_work(&priv->restart_work);
1338 }
1339 
1340 /*
1341  * Open/initialize the board. This is called (in the current kernel)
1342  * sometime after booting when the 'ifconfig' program is run.
1343  *
1344  * This routine should set everything up anew at each open, even
1345  * registers that "should" only need to be set once at boot, so that
1346  * there is non-reboot way to recover if something goes wrong.
1347  */
1348 static int enc28j60_net_open(struct net_device *dev)
1349 {
1350 	struct enc28j60_net *priv = netdev_priv(dev);
1351 
1352 	if (!is_valid_ether_addr(dev->dev_addr)) {
1353 		if (netif_msg_ifup(priv))
1354 			netdev_err(dev, "invalid MAC address %pM\n", dev->dev_addr);
1355 		return -EADDRNOTAVAIL;
1356 	}
1357 	/* Reset the hardware here (and take it out of low power mode) */
1358 	enc28j60_lowpower(priv, false);
1359 	enc28j60_hw_disable(priv);
1360 	if (!enc28j60_hw_init(priv)) {
1361 		if (netif_msg_ifup(priv))
1362 			netdev_err(dev, "hw_reset() failed\n");
1363 		return -EINVAL;
1364 	}
1365 	/* Update the MAC address (in case user has changed it) */
1366 	enc28j60_set_hw_macaddr(dev);
1367 	/* Enable interrupts */
1368 	enc28j60_hw_enable(priv);
1369 	/* check link status */
1370 	enc28j60_check_link_status(dev);
1371 	/* We are now ready to accept transmit requests from
1372 	 * the queueing layer of the networking.
1373 	 */
1374 	netif_start_queue(dev);
1375 
1376 	return 0;
1377 }
1378 
1379 /* The inverse routine to net_open(). */
1380 static int enc28j60_net_close(struct net_device *dev)
1381 {
1382 	struct enc28j60_net *priv = netdev_priv(dev);
1383 
1384 	enc28j60_hw_disable(priv);
1385 	enc28j60_lowpower(priv, true);
1386 	netif_stop_queue(dev);
1387 
1388 	return 0;
1389 }
1390 
1391 /*
1392  * Set or clear the multicast filter for this adapter
1393  * num_addrs == -1	Promiscuous mode, receive all packets
1394  * num_addrs == 0	Normal mode, filter out multicast packets
1395  * num_addrs > 0	Multicast mode, receive normal and MC packets
1396  */
1397 static void enc28j60_set_multicast_list(struct net_device *dev)
1398 {
1399 	struct enc28j60_net *priv = netdev_priv(dev);
1400 	int oldfilter = priv->rxfilter;
1401 
1402 	if (dev->flags & IFF_PROMISC) {
1403 		if (netif_msg_link(priv))
1404 			netdev_info(dev, "promiscuous mode\n");
1405 		priv->rxfilter = RXFILTER_PROMISC;
1406 	} else if ((dev->flags & IFF_ALLMULTI) || !netdev_mc_empty(dev)) {
1407 		if (netif_msg_link(priv))
1408 			netdev_info(dev, "%smulticast mode\n",
1409 				    (dev->flags & IFF_ALLMULTI) ? "all-" : "");
1410 		priv->rxfilter = RXFILTER_MULTI;
1411 	} else {
1412 		if (netif_msg_link(priv))
1413 			netdev_info(dev, "normal mode\n");
1414 		priv->rxfilter = RXFILTER_NORMAL;
1415 	}
1416 
1417 	if (oldfilter != priv->rxfilter)
1418 		schedule_work(&priv->setrx_work);
1419 }
1420 
1421 static void enc28j60_setrx_work_handler(struct work_struct *work)
1422 {
1423 	struct enc28j60_net *priv =
1424 		container_of(work, struct enc28j60_net, setrx_work);
1425 	struct device *dev = &priv->spi->dev;
1426 
1427 	if (priv->rxfilter == RXFILTER_PROMISC) {
1428 		if (netif_msg_drv(priv))
1429 			dev_printk(KERN_DEBUG, dev, "promiscuous mode\n");
1430 		locked_regb_write(priv, ERXFCON, 0x00);
1431 	} else if (priv->rxfilter == RXFILTER_MULTI) {
1432 		if (netif_msg_drv(priv))
1433 			dev_printk(KERN_DEBUG, dev, "multicast mode\n");
1434 		locked_regb_write(priv, ERXFCON,
1435 					ERXFCON_UCEN | ERXFCON_CRCEN |
1436 					ERXFCON_BCEN | ERXFCON_MCEN);
1437 	} else {
1438 		if (netif_msg_drv(priv))
1439 			dev_printk(KERN_DEBUG, dev, "normal mode\n");
1440 		locked_regb_write(priv, ERXFCON,
1441 					ERXFCON_UCEN | ERXFCON_CRCEN |
1442 					ERXFCON_BCEN);
1443 	}
1444 }
1445 
1446 static void enc28j60_restart_work_handler(struct work_struct *work)
1447 {
1448 	struct enc28j60_net *priv =
1449 			container_of(work, struct enc28j60_net, restart_work);
1450 	struct net_device *ndev = priv->netdev;
1451 	int ret;
1452 
1453 	rtnl_lock();
1454 	if (netif_running(ndev)) {
1455 		enc28j60_net_close(ndev);
1456 		ret = enc28j60_net_open(ndev);
1457 		if (unlikely(ret)) {
1458 			netdev_info(ndev, "could not restart %d\n", ret);
1459 			dev_close(ndev);
1460 		}
1461 	}
1462 	rtnl_unlock();
1463 }
1464 
1465 /* ......................... ETHTOOL SUPPORT ........................... */
1466 
1467 static void
1468 enc28j60_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1469 {
1470 	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1471 	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
1472 	strlcpy(info->bus_info,
1473 		dev_name(dev->dev.parent), sizeof(info->bus_info));
1474 }
1475 
1476 static int
1477 enc28j60_get_link_ksettings(struct net_device *dev,
1478 			    struct ethtool_link_ksettings *cmd)
1479 {
1480 	struct enc28j60_net *priv = netdev_priv(dev);
1481 
1482 	ethtool_link_ksettings_zero_link_mode(cmd, supported);
1483 	ethtool_link_ksettings_add_link_mode(cmd, supported, 10baseT_Half);
1484 	ethtool_link_ksettings_add_link_mode(cmd, supported, 10baseT_Full);
1485 	ethtool_link_ksettings_add_link_mode(cmd, supported, TP);
1486 
1487 	cmd->base.speed = SPEED_10;
1488 	cmd->base.duplex = priv->full_duplex ? DUPLEX_FULL : DUPLEX_HALF;
1489 	cmd->base.port	= PORT_TP;
1490 	cmd->base.autoneg = AUTONEG_DISABLE;
1491 
1492 	return 0;
1493 }
1494 
1495 static int
1496 enc28j60_set_link_ksettings(struct net_device *dev,
1497 			    const struct ethtool_link_ksettings *cmd)
1498 {
1499 	return enc28j60_setlink(dev, cmd->base.autoneg,
1500 				cmd->base.speed, cmd->base.duplex);
1501 }
1502 
1503 static u32 enc28j60_get_msglevel(struct net_device *dev)
1504 {
1505 	struct enc28j60_net *priv = netdev_priv(dev);
1506 	return priv->msg_enable;
1507 }
1508 
1509 static void enc28j60_set_msglevel(struct net_device *dev, u32 val)
1510 {
1511 	struct enc28j60_net *priv = netdev_priv(dev);
1512 	priv->msg_enable = val;
1513 }
1514 
1515 static const struct ethtool_ops enc28j60_ethtool_ops = {
1516 	.get_drvinfo	= enc28j60_get_drvinfo,
1517 	.get_msglevel	= enc28j60_get_msglevel,
1518 	.set_msglevel	= enc28j60_set_msglevel,
1519 	.get_link_ksettings = enc28j60_get_link_ksettings,
1520 	.set_link_ksettings = enc28j60_set_link_ksettings,
1521 };
1522 
1523 static int enc28j60_chipset_init(struct net_device *dev)
1524 {
1525 	struct enc28j60_net *priv = netdev_priv(dev);
1526 
1527 	return enc28j60_hw_init(priv);
1528 }
1529 
1530 static const struct net_device_ops enc28j60_netdev_ops = {
1531 	.ndo_open		= enc28j60_net_open,
1532 	.ndo_stop		= enc28j60_net_close,
1533 	.ndo_start_xmit		= enc28j60_send_packet,
1534 	.ndo_set_rx_mode	= enc28j60_set_multicast_list,
1535 	.ndo_set_mac_address	= enc28j60_set_mac_address,
1536 	.ndo_tx_timeout		= enc28j60_tx_timeout,
1537 	.ndo_validate_addr	= eth_validate_addr,
1538 };
1539 
1540 static int enc28j60_probe(struct spi_device *spi)
1541 {
1542 	struct net_device *dev;
1543 	struct enc28j60_net *priv;
1544 	int ret = 0;
1545 
1546 	if (netif_msg_drv(&debug))
1547 		dev_info(&spi->dev, "Ethernet driver %s loaded\n", DRV_VERSION);
1548 
1549 	dev = alloc_etherdev(sizeof(struct enc28j60_net));
1550 	if (!dev) {
1551 		ret = -ENOMEM;
1552 		goto error_alloc;
1553 	}
1554 	priv = netdev_priv(dev);
1555 
1556 	priv->netdev = dev;	/* priv to netdev reference */
1557 	priv->spi = spi;	/* priv to spi reference */
1558 	priv->msg_enable = netif_msg_init(debug.msg_enable, ENC28J60_MSG_DEFAULT);
1559 	mutex_init(&priv->lock);
1560 	INIT_WORK(&priv->tx_work, enc28j60_tx_work_handler);
1561 	INIT_WORK(&priv->setrx_work, enc28j60_setrx_work_handler);
1562 	INIT_WORK(&priv->irq_work, enc28j60_irq_work_handler);
1563 	INIT_WORK(&priv->restart_work, enc28j60_restart_work_handler);
1564 	spi_set_drvdata(spi, priv);	/* spi to priv reference */
1565 	SET_NETDEV_DEV(dev, &spi->dev);
1566 
1567 	if (!enc28j60_chipset_init(dev)) {
1568 		if (netif_msg_probe(priv))
1569 			dev_info(&spi->dev, "chip not found\n");
1570 		ret = -EIO;
1571 		goto error_irq;
1572 	}
1573 
1574 	if (device_get_ethdev_address(&spi->dev, dev))
1575 		eth_hw_addr_random(dev);
1576 	enc28j60_set_hw_macaddr(dev);
1577 
1578 	/* Board setup must set the relevant edge trigger type;
1579 	 * level triggers won't currently work.
1580 	 */
1581 	ret = request_irq(spi->irq, enc28j60_irq, 0, DRV_NAME, priv);
1582 	if (ret < 0) {
1583 		if (netif_msg_probe(priv))
1584 			dev_err(&spi->dev, "request irq %d failed (ret = %d)\n",
1585 				spi->irq, ret);
1586 		goto error_irq;
1587 	}
1588 
1589 	dev->if_port = IF_PORT_10BASET;
1590 	dev->irq = spi->irq;
1591 	dev->netdev_ops = &enc28j60_netdev_ops;
1592 	dev->watchdog_timeo = TX_TIMEOUT;
1593 	dev->ethtool_ops = &enc28j60_ethtool_ops;
1594 
1595 	enc28j60_lowpower(priv, true);
1596 
1597 	ret = register_netdev(dev);
1598 	if (ret) {
1599 		if (netif_msg_probe(priv))
1600 			dev_err(&spi->dev, "register netdev failed (ret = %d)\n",
1601 				ret);
1602 		goto error_register;
1603 	}
1604 
1605 	return 0;
1606 
1607 error_register:
1608 	free_irq(spi->irq, priv);
1609 error_irq:
1610 	free_netdev(dev);
1611 error_alloc:
1612 	return ret;
1613 }
1614 
1615 static void enc28j60_remove(struct spi_device *spi)
1616 {
1617 	struct enc28j60_net *priv = spi_get_drvdata(spi);
1618 
1619 	unregister_netdev(priv->netdev);
1620 	free_irq(spi->irq, priv);
1621 	free_netdev(priv->netdev);
1622 }
1623 
1624 static const struct of_device_id enc28j60_dt_ids[] = {
1625 	{ .compatible = "microchip,enc28j60" },
1626 	{ /* sentinel */ }
1627 };
1628 MODULE_DEVICE_TABLE(of, enc28j60_dt_ids);
1629 
1630 static struct spi_driver enc28j60_driver = {
1631 	.driver = {
1632 		.name = DRV_NAME,
1633 		.of_match_table = enc28j60_dt_ids,
1634 	 },
1635 	.probe = enc28j60_probe,
1636 	.remove = enc28j60_remove,
1637 };
1638 module_spi_driver(enc28j60_driver);
1639 
1640 MODULE_DESCRIPTION(DRV_NAME " ethernet driver");
1641 MODULE_AUTHOR("Claudio Lanconelli <lanconelli.claudio@eptar.com>");
1642 MODULE_LICENSE("GPL");
1643 module_param_named(debug, debug.msg_enable, int, 0);
1644 MODULE_PARM_DESC(debug, "Debug verbosity level in amount of bits set (0=none, ..., 31=all)");
1645 MODULE_ALIAS("spi:" DRV_NAME);
1646