1 // SPDX-License-Identifier: GPL-2.0-only
2 /* drivers/net/ethernet/micrel/ks8851.c
3  *
4  * Copyright 2009 Simtec Electronics
5  *	http://www.simtec.co.uk/
6  *	Ben Dooks <ben@simtec.co.uk>
7  */
8 
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <linux/interrupt.h>
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/netdevice.h>
15 #include <linux/etherdevice.h>
16 #include <linux/ethtool.h>
17 #include <linux/cache.h>
18 #include <linux/crc32.h>
19 #include <linux/mii.h>
20 #include <linux/gpio/consumer.h>
21 #include <linux/regulator/consumer.h>
22 
23 #include <linux/of_mdio.h>
24 #include <linux/of_net.h>
25 
26 #include "ks8851.h"
27 
28 /**
29  * ks8851_lock - register access lock
30  * @ks: The chip state
31  * @flags: Spinlock flags
32  *
33  * Claim chip register access lock
34  */
35 static void ks8851_lock(struct ks8851_net *ks, unsigned long *flags)
36 {
37 	ks->lock(ks, flags);
38 }
39 
40 /**
41  * ks8851_unlock - register access unlock
42  * @ks: The chip state
43  * @flags: Spinlock flags
44  *
45  * Release chip register access lock
46  */
47 static void ks8851_unlock(struct ks8851_net *ks, unsigned long *flags)
48 {
49 	ks->unlock(ks, flags);
50 }
51 
52 /**
53  * ks8851_wrreg16 - write 16bit register value to chip
54  * @ks: The chip state
55  * @reg: The register address
56  * @val: The value to write
57  *
58  * Issue a write to put the value @val into the register specified in @reg.
59  */
60 static void ks8851_wrreg16(struct ks8851_net *ks, unsigned int reg,
61 			   unsigned int val)
62 {
63 	ks->wrreg16(ks, reg, val);
64 }
65 
66 /**
67  * ks8851_rdreg16 - read 16 bit register from device
68  * @ks: The chip information
69  * @reg: The register address
70  *
71  * Read a 16bit register from the chip, returning the result
72  */
73 static unsigned int ks8851_rdreg16(struct ks8851_net *ks,
74 				   unsigned int reg)
75 {
76 	return ks->rdreg16(ks, reg);
77 }
78 
79 /**
80  * ks8851_soft_reset - issue one of the soft reset to the device
81  * @ks: The device state.
82  * @op: The bit(s) to set in the GRR
83  *
84  * Issue the relevant soft-reset command to the device's GRR register
85  * specified by @op.
86  *
87  * Note, the delays are in there as a caution to ensure that the reset
88  * has time to take effect and then complete. Since the datasheet does
89  * not currently specify the exact sequence, we have chosen something
90  * that seems to work with our device.
91  */
92 static void ks8851_soft_reset(struct ks8851_net *ks, unsigned op)
93 {
94 	ks8851_wrreg16(ks, KS_GRR, op);
95 	mdelay(1);	/* wait a short time to effect reset */
96 	ks8851_wrreg16(ks, KS_GRR, 0);
97 	mdelay(1);	/* wait for condition to clear */
98 }
99 
100 /**
101  * ks8851_set_powermode - set power mode of the device
102  * @ks: The device state
103  * @pwrmode: The power mode value to write to KS_PMECR.
104  *
105  * Change the power mode of the chip.
106  */
107 static void ks8851_set_powermode(struct ks8851_net *ks, unsigned pwrmode)
108 {
109 	unsigned pmecr;
110 
111 	netif_dbg(ks, hw, ks->netdev, "setting power mode %d\n", pwrmode);
112 
113 	pmecr = ks8851_rdreg16(ks, KS_PMECR);
114 	pmecr &= ~PMECR_PM_MASK;
115 	pmecr |= pwrmode;
116 
117 	ks8851_wrreg16(ks, KS_PMECR, pmecr);
118 }
119 
120 /**
121  * ks8851_write_mac_addr - write mac address to device registers
122  * @dev: The network device
123  *
124  * Update the KS8851 MAC address registers from the address in @dev.
125  *
126  * This call assumes that the chip is not running, so there is no need to
127  * shutdown the RXQ process whilst setting this.
128 */
129 static int ks8851_write_mac_addr(struct net_device *dev)
130 {
131 	struct ks8851_net *ks = netdev_priv(dev);
132 	unsigned long flags;
133 	u16 val;
134 	int i;
135 
136 	ks8851_lock(ks, &flags);
137 
138 	/*
139 	 * Wake up chip in case it was powered off when stopped; otherwise,
140 	 * the first write to the MAC address does not take effect.
141 	 */
142 	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
143 
144 	for (i = 0; i < ETH_ALEN; i += 2) {
145 		val = (dev->dev_addr[i] << 8) | dev->dev_addr[i + 1];
146 		ks8851_wrreg16(ks, KS_MAR(i), val);
147 	}
148 
149 	if (!netif_running(dev))
150 		ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
151 
152 	ks8851_unlock(ks, &flags);
153 
154 	return 0;
155 }
156 
157 /**
158  * ks8851_read_mac_addr - read mac address from device registers
159  * @dev: The network device
160  *
161  * Update our copy of the KS8851 MAC address from the registers of @dev.
162 */
163 static void ks8851_read_mac_addr(struct net_device *dev)
164 {
165 	struct ks8851_net *ks = netdev_priv(dev);
166 	unsigned long flags;
167 	u8 addr[ETH_ALEN];
168 	u16 reg;
169 	int i;
170 
171 	ks8851_lock(ks, &flags);
172 
173 	for (i = 0; i < ETH_ALEN; i += 2) {
174 		reg = ks8851_rdreg16(ks, KS_MAR(i));
175 		addr[i] = reg >> 8;
176 		addr[i + 1] = reg & 0xff;
177 	}
178 	eth_hw_addr_set(dev, addr);
179 
180 	ks8851_unlock(ks, &flags);
181 }
182 
183 /**
184  * ks8851_init_mac - initialise the mac address
185  * @ks: The device structure
186  * @np: The device node pointer
187  *
188  * Get or create the initial mac address for the device and then set that
189  * into the station address register. A mac address supplied in the device
190  * tree takes precedence. Otherwise, if there is an EEPROM present, then
191  * we try that. If no valid mac address is found we use eth_random_addr()
192  * to create a new one.
193  */
194 static void ks8851_init_mac(struct ks8851_net *ks, struct device_node *np)
195 {
196 	struct net_device *dev = ks->netdev;
197 	int ret;
198 
199 	ret = of_get_ethdev_address(np, dev);
200 	if (!ret) {
201 		ks8851_write_mac_addr(dev);
202 		return;
203 	}
204 
205 	if (ks->rc_ccr & CCR_EEPROM) {
206 		ks8851_read_mac_addr(dev);
207 		if (is_valid_ether_addr(dev->dev_addr))
208 			return;
209 
210 		netdev_err(ks->netdev, "invalid mac address read %pM\n",
211 				dev->dev_addr);
212 	}
213 
214 	eth_hw_addr_random(dev);
215 	ks8851_write_mac_addr(dev);
216 }
217 
218 /**
219  * ks8851_dbg_dumpkkt - dump initial packet contents to debug
220  * @ks: The device state
221  * @rxpkt: The data for the received packet
222  *
223  * Dump the initial data from the packet to dev_dbg().
224  */
225 static void ks8851_dbg_dumpkkt(struct ks8851_net *ks, u8 *rxpkt)
226 {
227 	netdev_dbg(ks->netdev,
228 		   "pkt %02x%02x%02x%02x %02x%02x%02x%02x %02x%02x%02x%02x\n",
229 		   rxpkt[4], rxpkt[5], rxpkt[6], rxpkt[7],
230 		   rxpkt[8], rxpkt[9], rxpkt[10], rxpkt[11],
231 		   rxpkt[12], rxpkt[13], rxpkt[14], rxpkt[15]);
232 }
233 
234 /**
235  * ks8851_rx_pkts - receive packets from the host
236  * @ks: The device information.
237  * @rxq: Queue of packets received in this function.
238  *
239  * This is called from the IRQ work queue when the system detects that there
240  * are packets in the receive queue. Find out how many packets there are and
241  * read them from the FIFO.
242  */
243 static void ks8851_rx_pkts(struct ks8851_net *ks, struct sk_buff_head *rxq)
244 {
245 	struct sk_buff *skb;
246 	unsigned rxfc;
247 	unsigned rxlen;
248 	unsigned rxstat;
249 	u8 *rxpkt;
250 
251 	rxfc = (ks8851_rdreg16(ks, KS_RXFCTR) >> 8) & 0xff;
252 
253 	netif_dbg(ks, rx_status, ks->netdev,
254 		  "%s: %d packets\n", __func__, rxfc);
255 
256 	/* Currently we're issuing a read per packet, but we could possibly
257 	 * improve the code by issuing a single read, getting the receive
258 	 * header, allocating the packet and then reading the packet data
259 	 * out in one go.
260 	 *
261 	 * This form of operation would require us to hold the SPI bus'
262 	 * chipselect low during the entie transaction to avoid any
263 	 * reset to the data stream coming from the chip.
264 	 */
265 
266 	for (; rxfc != 0; rxfc--) {
267 		rxstat = ks8851_rdreg16(ks, KS_RXFHSR);
268 		rxlen = ks8851_rdreg16(ks, KS_RXFHBCR) & RXFHBCR_CNT_MASK;
269 
270 		netif_dbg(ks, rx_status, ks->netdev,
271 			  "rx: stat 0x%04x, len 0x%04x\n", rxstat, rxlen);
272 
273 		/* the length of the packet includes the 32bit CRC */
274 
275 		/* set dma read address */
276 		ks8851_wrreg16(ks, KS_RXFDPR, RXFDPR_RXFPAI | 0x00);
277 
278 		/* start DMA access */
279 		ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA);
280 
281 		if (rxlen > 4) {
282 			unsigned int rxalign;
283 
284 			rxlen -= 4;
285 			rxalign = ALIGN(rxlen, 4);
286 			skb = netdev_alloc_skb_ip_align(ks->netdev, rxalign);
287 			if (skb) {
288 
289 				/* 4 bytes of status header + 4 bytes of
290 				 * garbage: we put them before ethernet
291 				 * header, so that they are copied,
292 				 * but ignored.
293 				 */
294 
295 				rxpkt = skb_put(skb, rxlen) - 8;
296 
297 				ks->rdfifo(ks, rxpkt, rxalign + 8);
298 
299 				if (netif_msg_pktdata(ks))
300 					ks8851_dbg_dumpkkt(ks, rxpkt);
301 
302 				skb->protocol = eth_type_trans(skb, ks->netdev);
303 				__skb_queue_tail(rxq, skb);
304 
305 				ks->netdev->stats.rx_packets++;
306 				ks->netdev->stats.rx_bytes += rxlen;
307 			}
308 		}
309 
310 		/* end DMA access and dequeue packet */
311 		ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_RRXEF);
312 	}
313 }
314 
315 /**
316  * ks8851_irq - IRQ handler for dealing with interrupt requests
317  * @irq: IRQ number
318  * @_ks: cookie
319  *
320  * This handler is invoked when the IRQ line asserts to find out what happened.
321  * As we cannot allow ourselves to sleep in HARDIRQ context, this handler runs
322  * in thread context.
323  *
324  * Read the interrupt status, work out what needs to be done and then clear
325  * any of the interrupts that are not needed.
326  */
327 static irqreturn_t ks8851_irq(int irq, void *_ks)
328 {
329 	struct ks8851_net *ks = _ks;
330 	struct sk_buff_head rxq;
331 	unsigned long flags;
332 	unsigned int status;
333 	struct sk_buff *skb;
334 
335 	ks8851_lock(ks, &flags);
336 
337 	status = ks8851_rdreg16(ks, KS_ISR);
338 	ks8851_wrreg16(ks, KS_ISR, status);
339 
340 	netif_dbg(ks, intr, ks->netdev,
341 		  "%s: status 0x%04x\n", __func__, status);
342 
343 	if (status & IRQ_LDI) {
344 		u16 pmecr = ks8851_rdreg16(ks, KS_PMECR);
345 		pmecr &= ~PMECR_WKEVT_MASK;
346 		ks8851_wrreg16(ks, KS_PMECR, pmecr | PMECR_WKEVT_LINK);
347 	}
348 
349 	if (status & IRQ_TXI) {
350 		unsigned short tx_space = ks8851_rdreg16(ks, KS_TXMIR);
351 
352 		netif_dbg(ks, intr, ks->netdev,
353 			  "%s: txspace %d\n", __func__, tx_space);
354 
355 		spin_lock(&ks->statelock);
356 		ks->tx_space = tx_space;
357 		if (netif_queue_stopped(ks->netdev))
358 			netif_wake_queue(ks->netdev);
359 		spin_unlock(&ks->statelock);
360 	}
361 
362 	if (status & IRQ_SPIBEI) {
363 		netdev_err(ks->netdev, "%s: spi bus error\n", __func__);
364 	}
365 
366 	if (status & IRQ_RXI) {
367 		/* the datasheet says to disable the rx interrupt during
368 		 * packet read-out, however we're masking the interrupt
369 		 * from the device so do not bother masking just the RX
370 		 * from the device. */
371 
372 		__skb_queue_head_init(&rxq);
373 		ks8851_rx_pkts(ks, &rxq);
374 	}
375 
376 	/* if something stopped the rx process, probably due to wanting
377 	 * to change the rx settings, then do something about restarting
378 	 * it. */
379 	if (status & IRQ_RXPSI) {
380 		struct ks8851_rxctrl *rxc = &ks->rxctrl;
381 
382 		/* update the multicast hash table */
383 		ks8851_wrreg16(ks, KS_MAHTR0, rxc->mchash[0]);
384 		ks8851_wrreg16(ks, KS_MAHTR1, rxc->mchash[1]);
385 		ks8851_wrreg16(ks, KS_MAHTR2, rxc->mchash[2]);
386 		ks8851_wrreg16(ks, KS_MAHTR3, rxc->mchash[3]);
387 
388 		ks8851_wrreg16(ks, KS_RXCR2, rxc->rxcr2);
389 		ks8851_wrreg16(ks, KS_RXCR1, rxc->rxcr1);
390 	}
391 
392 	ks8851_unlock(ks, &flags);
393 
394 	if (status & IRQ_LCI)
395 		mii_check_link(&ks->mii);
396 
397 	if (status & IRQ_RXI)
398 		while ((skb = __skb_dequeue(&rxq)))
399 			netif_rx(skb);
400 
401 	return IRQ_HANDLED;
402 }
403 
404 /**
405  * ks8851_flush_tx_work - flush outstanding TX work
406  * @ks: The device state
407  */
408 static void ks8851_flush_tx_work(struct ks8851_net *ks)
409 {
410 	if (ks->flush_tx_work)
411 		ks->flush_tx_work(ks);
412 }
413 
414 /**
415  * ks8851_net_open - open network device
416  * @dev: The network device being opened.
417  *
418  * Called when the network device is marked active, such as a user executing
419  * 'ifconfig up' on the device.
420  */
421 static int ks8851_net_open(struct net_device *dev)
422 {
423 	struct ks8851_net *ks = netdev_priv(dev);
424 	unsigned long flags;
425 	int ret;
426 
427 	ret = request_threaded_irq(dev->irq, NULL, ks8851_irq,
428 				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
429 				   dev->name, ks);
430 	if (ret < 0) {
431 		netdev_err(dev, "failed to get irq\n");
432 		return ret;
433 	}
434 
435 	/* lock the card, even if we may not actually be doing anything
436 	 * else at the moment */
437 	ks8851_lock(ks, &flags);
438 
439 	netif_dbg(ks, ifup, ks->netdev, "opening\n");
440 
441 	/* bring chip out of any power saving mode it was in */
442 	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
443 
444 	/* issue a soft reset to the RX/TX QMU to put it into a known
445 	 * state. */
446 	ks8851_soft_reset(ks, GRR_QMU);
447 
448 	/* setup transmission parameters */
449 
450 	ks8851_wrreg16(ks, KS_TXCR, (TXCR_TXE | /* enable transmit process */
451 				     TXCR_TXPE | /* pad to min length */
452 				     TXCR_TXCRC | /* add CRC */
453 				     TXCR_TXFCE)); /* enable flow control */
454 
455 	/* auto-increment tx data, reset tx pointer */
456 	ks8851_wrreg16(ks, KS_TXFDPR, TXFDPR_TXFPAI);
457 
458 	/* setup receiver control */
459 
460 	ks8851_wrreg16(ks, KS_RXCR1, (RXCR1_RXPAFMA | /*  from mac filter */
461 				      RXCR1_RXFCE | /* enable flow control */
462 				      RXCR1_RXBE | /* broadcast enable */
463 				      RXCR1_RXUE | /* unicast enable */
464 				      RXCR1_RXE)); /* enable rx block */
465 
466 	/* transfer entire frames out in one go */
467 	ks8851_wrreg16(ks, KS_RXCR2, RXCR2_SRDBL_FRAME);
468 
469 	/* set receive counter timeouts */
470 	ks8851_wrreg16(ks, KS_RXDTTR, 1000); /* 1ms after first frame to IRQ */
471 	ks8851_wrreg16(ks, KS_RXDBCTR, 4096); /* >4Kbytes in buffer to IRQ */
472 	ks8851_wrreg16(ks, KS_RXFCTR, 10);  /* 10 frames to IRQ */
473 
474 	ks->rc_rxqcr = (RXQCR_RXFCTE |  /* IRQ on frame count exceeded */
475 			RXQCR_RXDBCTE | /* IRQ on byte count exceeded */
476 			RXQCR_RXDTTE);  /* IRQ on time exceeded */
477 
478 	ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr);
479 
480 	/* clear then enable interrupts */
481 	ks8851_wrreg16(ks, KS_ISR, ks->rc_ier);
482 	ks8851_wrreg16(ks, KS_IER, ks->rc_ier);
483 
484 	ks->queued_len = 0;
485 	netif_start_queue(ks->netdev);
486 
487 	netif_dbg(ks, ifup, ks->netdev, "network device up\n");
488 
489 	ks8851_unlock(ks, &flags);
490 	mii_check_link(&ks->mii);
491 	return 0;
492 }
493 
494 /**
495  * ks8851_net_stop - close network device
496  * @dev: The device being closed.
497  *
498  * Called to close down a network device which has been active. Cancell any
499  * work, shutdown the RX and TX process and then place the chip into a low
500  * power state whilst it is not being used.
501  */
502 static int ks8851_net_stop(struct net_device *dev)
503 {
504 	struct ks8851_net *ks = netdev_priv(dev);
505 	unsigned long flags;
506 
507 	netif_info(ks, ifdown, dev, "shutting down\n");
508 
509 	netif_stop_queue(dev);
510 
511 	ks8851_lock(ks, &flags);
512 	/* turn off the IRQs and ack any outstanding */
513 	ks8851_wrreg16(ks, KS_IER, 0x0000);
514 	ks8851_wrreg16(ks, KS_ISR, 0xffff);
515 	ks8851_unlock(ks, &flags);
516 
517 	/* stop any outstanding work */
518 	ks8851_flush_tx_work(ks);
519 	flush_work(&ks->rxctrl_work);
520 
521 	ks8851_lock(ks, &flags);
522 	/* shutdown RX process */
523 	ks8851_wrreg16(ks, KS_RXCR1, 0x0000);
524 
525 	/* shutdown TX process */
526 	ks8851_wrreg16(ks, KS_TXCR, 0x0000);
527 
528 	/* set powermode to soft power down to save power */
529 	ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
530 	ks8851_unlock(ks, &flags);
531 
532 	/* ensure any queued tx buffers are dumped */
533 	while (!skb_queue_empty(&ks->txq)) {
534 		struct sk_buff *txb = skb_dequeue(&ks->txq);
535 
536 		netif_dbg(ks, ifdown, ks->netdev,
537 			  "%s: freeing txb %p\n", __func__, txb);
538 
539 		dev_kfree_skb(txb);
540 	}
541 
542 	free_irq(dev->irq, ks);
543 
544 	return 0;
545 }
546 
547 /**
548  * ks8851_start_xmit - transmit packet
549  * @skb: The buffer to transmit
550  * @dev: The device used to transmit the packet.
551  *
552  * Called by the network layer to transmit the @skb. Queue the packet for
553  * the device and schedule the necessary work to transmit the packet when
554  * it is free.
555  *
556  * We do this to firstly avoid sleeping with the network device locked,
557  * and secondly so we can round up more than one packet to transmit which
558  * means we can try and avoid generating too many transmit done interrupts.
559  */
560 static netdev_tx_t ks8851_start_xmit(struct sk_buff *skb,
561 				     struct net_device *dev)
562 {
563 	struct ks8851_net *ks = netdev_priv(dev);
564 
565 	return ks->start_xmit(skb, dev);
566 }
567 
568 /**
569  * ks8851_rxctrl_work - work handler to change rx mode
570  * @work: The work structure this belongs to.
571  *
572  * Lock the device and issue the necessary changes to the receive mode from
573  * the network device layer. This is done so that we can do this without
574  * having to sleep whilst holding the network device lock.
575  *
576  * Since the recommendation from Micrel is that the RXQ is shutdown whilst the
577  * receive parameters are programmed, we issue a write to disable the RXQ and
578  * then wait for the interrupt handler to be triggered once the RXQ shutdown is
579  * complete. The interrupt handler then writes the new values into the chip.
580  */
581 static void ks8851_rxctrl_work(struct work_struct *work)
582 {
583 	struct ks8851_net *ks = container_of(work, struct ks8851_net, rxctrl_work);
584 	unsigned long flags;
585 
586 	ks8851_lock(ks, &flags);
587 
588 	/* need to shutdown RXQ before modifying filter parameters */
589 	ks8851_wrreg16(ks, KS_RXCR1, 0x00);
590 
591 	ks8851_unlock(ks, &flags);
592 }
593 
594 static void ks8851_set_rx_mode(struct net_device *dev)
595 {
596 	struct ks8851_net *ks = netdev_priv(dev);
597 	struct ks8851_rxctrl rxctrl;
598 
599 	memset(&rxctrl, 0, sizeof(rxctrl));
600 
601 	if (dev->flags & IFF_PROMISC) {
602 		/* interface to receive everything */
603 
604 		rxctrl.rxcr1 = RXCR1_RXAE | RXCR1_RXINVF;
605 	} else if (dev->flags & IFF_ALLMULTI) {
606 		/* accept all multicast packets */
607 
608 		rxctrl.rxcr1 = (RXCR1_RXME | RXCR1_RXAE |
609 				RXCR1_RXPAFMA | RXCR1_RXMAFMA);
610 	} else if (dev->flags & IFF_MULTICAST && !netdev_mc_empty(dev)) {
611 		struct netdev_hw_addr *ha;
612 		u32 crc;
613 
614 		/* accept some multicast */
615 
616 		netdev_for_each_mc_addr(ha, dev) {
617 			crc = ether_crc(ETH_ALEN, ha->addr);
618 			crc >>= (32 - 6);  /* get top six bits */
619 
620 			rxctrl.mchash[crc >> 4] |= (1 << (crc & 0xf));
621 		}
622 
623 		rxctrl.rxcr1 = RXCR1_RXME | RXCR1_RXPAFMA;
624 	} else {
625 		/* just accept broadcast / unicast */
626 		rxctrl.rxcr1 = RXCR1_RXPAFMA;
627 	}
628 
629 	rxctrl.rxcr1 |= (RXCR1_RXUE | /* unicast enable */
630 			 RXCR1_RXBE | /* broadcast enable */
631 			 RXCR1_RXE | /* RX process enable */
632 			 RXCR1_RXFCE); /* enable flow control */
633 
634 	rxctrl.rxcr2 |= RXCR2_SRDBL_FRAME;
635 
636 	/* schedule work to do the actual set of the data if needed */
637 
638 	spin_lock(&ks->statelock);
639 
640 	if (memcmp(&rxctrl, &ks->rxctrl, sizeof(rxctrl)) != 0) {
641 		memcpy(&ks->rxctrl, &rxctrl, sizeof(ks->rxctrl));
642 		schedule_work(&ks->rxctrl_work);
643 	}
644 
645 	spin_unlock(&ks->statelock);
646 }
647 
648 static int ks8851_set_mac_address(struct net_device *dev, void *addr)
649 {
650 	struct sockaddr *sa = addr;
651 
652 	if (netif_running(dev))
653 		return -EBUSY;
654 
655 	if (!is_valid_ether_addr(sa->sa_data))
656 		return -EADDRNOTAVAIL;
657 
658 	eth_hw_addr_set(dev, sa->sa_data);
659 	return ks8851_write_mac_addr(dev);
660 }
661 
662 static int ks8851_net_ioctl(struct net_device *dev, struct ifreq *req, int cmd)
663 {
664 	struct ks8851_net *ks = netdev_priv(dev);
665 
666 	if (!netif_running(dev))
667 		return -EINVAL;
668 
669 	return generic_mii_ioctl(&ks->mii, if_mii(req), cmd, NULL);
670 }
671 
672 static const struct net_device_ops ks8851_netdev_ops = {
673 	.ndo_open		= ks8851_net_open,
674 	.ndo_stop		= ks8851_net_stop,
675 	.ndo_eth_ioctl		= ks8851_net_ioctl,
676 	.ndo_start_xmit		= ks8851_start_xmit,
677 	.ndo_set_mac_address	= ks8851_set_mac_address,
678 	.ndo_set_rx_mode	= ks8851_set_rx_mode,
679 	.ndo_validate_addr	= eth_validate_addr,
680 };
681 
682 /* ethtool support */
683 
684 static void ks8851_get_drvinfo(struct net_device *dev,
685 			       struct ethtool_drvinfo *di)
686 {
687 	strscpy(di->driver, "KS8851", sizeof(di->driver));
688 	strscpy(di->version, "1.00", sizeof(di->version));
689 	strscpy(di->bus_info, dev_name(dev->dev.parent), sizeof(di->bus_info));
690 }
691 
692 static u32 ks8851_get_msglevel(struct net_device *dev)
693 {
694 	struct ks8851_net *ks = netdev_priv(dev);
695 	return ks->msg_enable;
696 }
697 
698 static void ks8851_set_msglevel(struct net_device *dev, u32 to)
699 {
700 	struct ks8851_net *ks = netdev_priv(dev);
701 	ks->msg_enable = to;
702 }
703 
704 static int ks8851_get_link_ksettings(struct net_device *dev,
705 				     struct ethtool_link_ksettings *cmd)
706 {
707 	struct ks8851_net *ks = netdev_priv(dev);
708 
709 	mii_ethtool_get_link_ksettings(&ks->mii, cmd);
710 
711 	return 0;
712 }
713 
714 static int ks8851_set_link_ksettings(struct net_device *dev,
715 				     const struct ethtool_link_ksettings *cmd)
716 {
717 	struct ks8851_net *ks = netdev_priv(dev);
718 	return mii_ethtool_set_link_ksettings(&ks->mii, cmd);
719 }
720 
721 static u32 ks8851_get_link(struct net_device *dev)
722 {
723 	struct ks8851_net *ks = netdev_priv(dev);
724 	return mii_link_ok(&ks->mii);
725 }
726 
727 static int ks8851_nway_reset(struct net_device *dev)
728 {
729 	struct ks8851_net *ks = netdev_priv(dev);
730 	return mii_nway_restart(&ks->mii);
731 }
732 
733 /* EEPROM support */
734 
735 static void ks8851_eeprom_regread(struct eeprom_93cx6 *ee)
736 {
737 	struct ks8851_net *ks = ee->data;
738 	unsigned val;
739 
740 	val = ks8851_rdreg16(ks, KS_EEPCR);
741 
742 	ee->reg_data_out = (val & EEPCR_EESB) ? 1 : 0;
743 	ee->reg_data_clock = (val & EEPCR_EESCK) ? 1 : 0;
744 	ee->reg_chip_select = (val & EEPCR_EECS) ? 1 : 0;
745 }
746 
747 static void ks8851_eeprom_regwrite(struct eeprom_93cx6 *ee)
748 {
749 	struct ks8851_net *ks = ee->data;
750 	unsigned val = EEPCR_EESA;	/* default - eeprom access on */
751 
752 	if (ee->drive_data)
753 		val |= EEPCR_EESRWA;
754 	if (ee->reg_data_in)
755 		val |= EEPCR_EEDO;
756 	if (ee->reg_data_clock)
757 		val |= EEPCR_EESCK;
758 	if (ee->reg_chip_select)
759 		val |= EEPCR_EECS;
760 
761 	ks8851_wrreg16(ks, KS_EEPCR, val);
762 }
763 
764 /**
765  * ks8851_eeprom_claim - claim device EEPROM and activate the interface
766  * @ks: The network device state.
767  *
768  * Check for the presence of an EEPROM, and then activate software access
769  * to the device.
770  */
771 static int ks8851_eeprom_claim(struct ks8851_net *ks)
772 {
773 	/* start with clock low, cs high */
774 	ks8851_wrreg16(ks, KS_EEPCR, EEPCR_EESA | EEPCR_EECS);
775 	return 0;
776 }
777 
778 /**
779  * ks8851_eeprom_release - release the EEPROM interface
780  * @ks: The device state
781  *
782  * Release the software access to the device EEPROM
783  */
784 static void ks8851_eeprom_release(struct ks8851_net *ks)
785 {
786 	unsigned val = ks8851_rdreg16(ks, KS_EEPCR);
787 
788 	ks8851_wrreg16(ks, KS_EEPCR, val & ~EEPCR_EESA);
789 }
790 
791 #define KS_EEPROM_MAGIC (0x00008851)
792 
793 static int ks8851_set_eeprom(struct net_device *dev,
794 			     struct ethtool_eeprom *ee, u8 *data)
795 {
796 	struct ks8851_net *ks = netdev_priv(dev);
797 	int offset = ee->offset;
798 	unsigned long flags;
799 	int len = ee->len;
800 	u16 tmp;
801 
802 	/* currently only support byte writing */
803 	if (len != 1)
804 		return -EINVAL;
805 
806 	if (ee->magic != KS_EEPROM_MAGIC)
807 		return -EINVAL;
808 
809 	if (!(ks->rc_ccr & CCR_EEPROM))
810 		return -ENOENT;
811 
812 	ks8851_lock(ks, &flags);
813 
814 	ks8851_eeprom_claim(ks);
815 
816 	eeprom_93cx6_wren(&ks->eeprom, true);
817 
818 	/* ethtool currently only supports writing bytes, which means
819 	 * we have to read/modify/write our 16bit EEPROMs */
820 
821 	eeprom_93cx6_read(&ks->eeprom, offset/2, &tmp);
822 
823 	if (offset & 1) {
824 		tmp &= 0xff;
825 		tmp |= *data << 8;
826 	} else {
827 		tmp &= 0xff00;
828 		tmp |= *data;
829 	}
830 
831 	eeprom_93cx6_write(&ks->eeprom, offset/2, tmp);
832 	eeprom_93cx6_wren(&ks->eeprom, false);
833 
834 	ks8851_eeprom_release(ks);
835 	ks8851_unlock(ks, &flags);
836 
837 	return 0;
838 }
839 
840 static int ks8851_get_eeprom(struct net_device *dev,
841 			     struct ethtool_eeprom *ee, u8 *data)
842 {
843 	struct ks8851_net *ks = netdev_priv(dev);
844 	int offset = ee->offset;
845 	unsigned long flags;
846 	int len = ee->len;
847 
848 	/* must be 2 byte aligned */
849 	if (len & 1 || offset & 1)
850 		return -EINVAL;
851 
852 	if (!(ks->rc_ccr & CCR_EEPROM))
853 		return -ENOENT;
854 
855 	ks8851_lock(ks, &flags);
856 
857 	ks8851_eeprom_claim(ks);
858 
859 	ee->magic = KS_EEPROM_MAGIC;
860 
861 	eeprom_93cx6_multiread(&ks->eeprom, offset/2, (__le16 *)data, len/2);
862 	ks8851_eeprom_release(ks);
863 	ks8851_unlock(ks, &flags);
864 
865 	return 0;
866 }
867 
868 static int ks8851_get_eeprom_len(struct net_device *dev)
869 {
870 	struct ks8851_net *ks = netdev_priv(dev);
871 
872 	/* currently, we assume it is an 93C46 attached, so return 128 */
873 	return ks->rc_ccr & CCR_EEPROM ? 128 : 0;
874 }
875 
876 static const struct ethtool_ops ks8851_ethtool_ops = {
877 	.get_drvinfo	= ks8851_get_drvinfo,
878 	.get_msglevel	= ks8851_get_msglevel,
879 	.set_msglevel	= ks8851_set_msglevel,
880 	.get_link	= ks8851_get_link,
881 	.nway_reset	= ks8851_nway_reset,
882 	.get_eeprom_len	= ks8851_get_eeprom_len,
883 	.get_eeprom	= ks8851_get_eeprom,
884 	.set_eeprom	= ks8851_set_eeprom,
885 	.get_link_ksettings = ks8851_get_link_ksettings,
886 	.set_link_ksettings = ks8851_set_link_ksettings,
887 };
888 
889 /* MII interface controls */
890 
891 /**
892  * ks8851_phy_reg - convert MII register into a KS8851 register
893  * @reg: MII register number.
894  *
895  * Return the KS8851 register number for the corresponding MII PHY register
896  * if possible. Return zero if the MII register has no direct mapping to the
897  * KS8851 register set.
898  */
899 static int ks8851_phy_reg(int reg)
900 {
901 	switch (reg) {
902 	case MII_BMCR:
903 		return KS_P1MBCR;
904 	case MII_BMSR:
905 		return KS_P1MBSR;
906 	case MII_PHYSID1:
907 		return KS_PHY1ILR;
908 	case MII_PHYSID2:
909 		return KS_PHY1IHR;
910 	case MII_ADVERTISE:
911 		return KS_P1ANAR;
912 	case MII_LPA:
913 		return KS_P1ANLPR;
914 	}
915 
916 	return -EOPNOTSUPP;
917 }
918 
919 static int ks8851_phy_read_common(struct net_device *dev, int phy_addr, int reg)
920 {
921 	struct ks8851_net *ks = netdev_priv(dev);
922 	unsigned long flags;
923 	int result;
924 	int ksreg;
925 
926 	ksreg = ks8851_phy_reg(reg);
927 	if (ksreg < 0)
928 		return ksreg;
929 
930 	ks8851_lock(ks, &flags);
931 	result = ks8851_rdreg16(ks, ksreg);
932 	ks8851_unlock(ks, &flags);
933 
934 	return result;
935 }
936 
937 /**
938  * ks8851_phy_read - MII interface PHY register read.
939  * @dev: The network device the PHY is on.
940  * @phy_addr: Address of PHY (ignored as we only have one)
941  * @reg: The register to read.
942  *
943  * This call reads data from the PHY register specified in @reg. Since the
944  * device does not support all the MII registers, the non-existent values
945  * are always returned as zero.
946  *
947  * We return zero for unsupported registers as the MII code does not check
948  * the value returned for any error status, and simply returns it to the
949  * caller. The mii-tool that the driver was tested with takes any -ve error
950  * as real PHY capabilities, thus displaying incorrect data to the user.
951  */
952 static int ks8851_phy_read(struct net_device *dev, int phy_addr, int reg)
953 {
954 	int ret;
955 
956 	ret = ks8851_phy_read_common(dev, phy_addr, reg);
957 	if (ret < 0)
958 		return 0x0;	/* no error return allowed, so use zero */
959 
960 	return ret;
961 }
962 
963 static void ks8851_phy_write(struct net_device *dev,
964 			     int phy, int reg, int value)
965 {
966 	struct ks8851_net *ks = netdev_priv(dev);
967 	unsigned long flags;
968 	int ksreg;
969 
970 	ksreg = ks8851_phy_reg(reg);
971 	if (ksreg >= 0) {
972 		ks8851_lock(ks, &flags);
973 		ks8851_wrreg16(ks, ksreg, value);
974 		ks8851_unlock(ks, &flags);
975 	}
976 }
977 
978 static int ks8851_mdio_read(struct mii_bus *bus, int phy_id, int reg)
979 {
980 	struct ks8851_net *ks = bus->priv;
981 
982 	if (phy_id != 0)
983 		return -EOPNOTSUPP;
984 
985 	/* KS8851 PHY ID registers are swapped in HW, swap them back. */
986 	if (reg == MII_PHYSID1)
987 		reg = MII_PHYSID2;
988 	else if (reg == MII_PHYSID2)
989 		reg = MII_PHYSID1;
990 
991 	return ks8851_phy_read_common(ks->netdev, phy_id, reg);
992 }
993 
994 static int ks8851_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
995 {
996 	struct ks8851_net *ks = bus->priv;
997 
998 	ks8851_phy_write(ks->netdev, phy_id, reg, val);
999 	return 0;
1000 }
1001 
1002 /**
1003  * ks8851_read_selftest - read the selftest memory info.
1004  * @ks: The device state
1005  *
1006  * Read and check the TX/RX memory selftest information.
1007  */
1008 static void ks8851_read_selftest(struct ks8851_net *ks)
1009 {
1010 	unsigned both_done = MBIR_TXMBF | MBIR_RXMBF;
1011 	unsigned rd;
1012 
1013 	rd = ks8851_rdreg16(ks, KS_MBIR);
1014 
1015 	if ((rd & both_done) != both_done) {
1016 		netdev_warn(ks->netdev, "Memory selftest not finished\n");
1017 		return;
1018 	}
1019 
1020 	if (rd & MBIR_TXMBFA)
1021 		netdev_err(ks->netdev, "TX memory selftest fail\n");
1022 
1023 	if (rd & MBIR_RXMBFA)
1024 		netdev_err(ks->netdev, "RX memory selftest fail\n");
1025 }
1026 
1027 /* driver bus management functions */
1028 
1029 #ifdef CONFIG_PM_SLEEP
1030 
1031 int ks8851_suspend(struct device *dev)
1032 {
1033 	struct ks8851_net *ks = dev_get_drvdata(dev);
1034 	struct net_device *netdev = ks->netdev;
1035 
1036 	if (netif_running(netdev)) {
1037 		netif_device_detach(netdev);
1038 		ks8851_net_stop(netdev);
1039 	}
1040 
1041 	return 0;
1042 }
1043 EXPORT_SYMBOL_GPL(ks8851_suspend);
1044 
1045 int ks8851_resume(struct device *dev)
1046 {
1047 	struct ks8851_net *ks = dev_get_drvdata(dev);
1048 	struct net_device *netdev = ks->netdev;
1049 
1050 	if (netif_running(netdev)) {
1051 		ks8851_net_open(netdev);
1052 		netif_device_attach(netdev);
1053 	}
1054 
1055 	return 0;
1056 }
1057 EXPORT_SYMBOL_GPL(ks8851_resume);
1058 #endif
1059 
1060 static int ks8851_register_mdiobus(struct ks8851_net *ks, struct device *dev)
1061 {
1062 	struct mii_bus *mii_bus;
1063 	int ret;
1064 
1065 	mii_bus = mdiobus_alloc();
1066 	if (!mii_bus)
1067 		return -ENOMEM;
1068 
1069 	mii_bus->name = "ks8851_eth_mii";
1070 	mii_bus->read = ks8851_mdio_read;
1071 	mii_bus->write = ks8851_mdio_write;
1072 	mii_bus->priv = ks;
1073 	mii_bus->parent = dev;
1074 	mii_bus->phy_mask = ~((u32)BIT(0));
1075 	snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
1076 
1077 	ret = mdiobus_register(mii_bus);
1078 	if (ret)
1079 		goto err_mdiobus_register;
1080 
1081 	ks->mii_bus = mii_bus;
1082 
1083 	return 0;
1084 
1085 err_mdiobus_register:
1086 	mdiobus_free(mii_bus);
1087 	return ret;
1088 }
1089 
1090 static void ks8851_unregister_mdiobus(struct ks8851_net *ks)
1091 {
1092 	mdiobus_unregister(ks->mii_bus);
1093 	mdiobus_free(ks->mii_bus);
1094 }
1095 
1096 int ks8851_probe_common(struct net_device *netdev, struct device *dev,
1097 			int msg_en)
1098 {
1099 	struct ks8851_net *ks = netdev_priv(netdev);
1100 	unsigned cider;
1101 	int ret;
1102 
1103 	ks->netdev = netdev;
1104 	ks->tx_space = 6144;
1105 
1106 	ks->gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
1107 	ret = PTR_ERR_OR_ZERO(ks->gpio);
1108 	if (ret) {
1109 		if (ret != -EPROBE_DEFER)
1110 			dev_err(dev, "reset gpio request failed: %d\n", ret);
1111 		return ret;
1112 	}
1113 
1114 	ret = gpiod_set_consumer_name(ks->gpio, "ks8851_rst_n");
1115 	if (ret) {
1116 		dev_err(dev, "failed to set reset gpio name: %d\n", ret);
1117 		return ret;
1118 	}
1119 
1120 	ks->vdd_io = devm_regulator_get(dev, "vdd-io");
1121 	if (IS_ERR(ks->vdd_io)) {
1122 		ret = PTR_ERR(ks->vdd_io);
1123 		goto err_reg_io;
1124 	}
1125 
1126 	ret = regulator_enable(ks->vdd_io);
1127 	if (ret) {
1128 		dev_err(dev, "regulator vdd_io enable fail: %d\n", ret);
1129 		goto err_reg_io;
1130 	}
1131 
1132 	ks->vdd_reg = devm_regulator_get(dev, "vdd");
1133 	if (IS_ERR(ks->vdd_reg)) {
1134 		ret = PTR_ERR(ks->vdd_reg);
1135 		goto err_reg;
1136 	}
1137 
1138 	ret = regulator_enable(ks->vdd_reg);
1139 	if (ret) {
1140 		dev_err(dev, "regulator vdd enable fail: %d\n", ret);
1141 		goto err_reg;
1142 	}
1143 
1144 	if (ks->gpio) {
1145 		usleep_range(10000, 11000);
1146 		gpiod_set_value_cansleep(ks->gpio, 0);
1147 	}
1148 
1149 	spin_lock_init(&ks->statelock);
1150 
1151 	INIT_WORK(&ks->rxctrl_work, ks8851_rxctrl_work);
1152 
1153 	SET_NETDEV_DEV(netdev, dev);
1154 
1155 	/* setup EEPROM state */
1156 	ks->eeprom.data = ks;
1157 	ks->eeprom.width = PCI_EEPROM_WIDTH_93C46;
1158 	ks->eeprom.register_read = ks8851_eeprom_regread;
1159 	ks->eeprom.register_write = ks8851_eeprom_regwrite;
1160 
1161 	/* setup mii state */
1162 	ks->mii.dev		= netdev;
1163 	ks->mii.phy_id		= 1;
1164 	ks->mii.phy_id_mask	= 1;
1165 	ks->mii.reg_num_mask	= 0xf;
1166 	ks->mii.mdio_read	= ks8851_phy_read;
1167 	ks->mii.mdio_write	= ks8851_phy_write;
1168 
1169 	dev_info(dev, "message enable is %d\n", msg_en);
1170 
1171 	ret = ks8851_register_mdiobus(ks, dev);
1172 	if (ret)
1173 		goto err_mdio;
1174 
1175 	/* set the default message enable */
1176 	ks->msg_enable = netif_msg_init(msg_en, NETIF_MSG_DRV |
1177 						NETIF_MSG_PROBE |
1178 						NETIF_MSG_LINK);
1179 
1180 	skb_queue_head_init(&ks->txq);
1181 
1182 	netdev->ethtool_ops = &ks8851_ethtool_ops;
1183 
1184 	dev_set_drvdata(dev, ks);
1185 
1186 	netif_carrier_off(ks->netdev);
1187 	netdev->if_port = IF_PORT_100BASET;
1188 	netdev->netdev_ops = &ks8851_netdev_ops;
1189 
1190 	/* issue a global soft reset to reset the device. */
1191 	ks8851_soft_reset(ks, GRR_GSR);
1192 
1193 	/* simple check for a valid chip being connected to the bus */
1194 	cider = ks8851_rdreg16(ks, KS_CIDER);
1195 	if ((cider & ~CIDER_REV_MASK) != CIDER_ID) {
1196 		dev_err(dev, "failed to read device ID\n");
1197 		ret = -ENODEV;
1198 		goto err_id;
1199 	}
1200 
1201 	/* cache the contents of the CCR register for EEPROM, etc. */
1202 	ks->rc_ccr = ks8851_rdreg16(ks, KS_CCR);
1203 
1204 	ks8851_read_selftest(ks);
1205 	ks8851_init_mac(ks, dev->of_node);
1206 
1207 	ret = register_netdev(netdev);
1208 	if (ret) {
1209 		dev_err(dev, "failed to register network device\n");
1210 		goto err_id;
1211 	}
1212 
1213 	netdev_info(netdev, "revision %d, MAC %pM, IRQ %d, %s EEPROM\n",
1214 		    CIDER_REV_GET(cider), netdev->dev_addr, netdev->irq,
1215 		    ks->rc_ccr & CCR_EEPROM ? "has" : "no");
1216 
1217 	return 0;
1218 
1219 err_id:
1220 	ks8851_unregister_mdiobus(ks);
1221 err_mdio:
1222 	if (ks->gpio)
1223 		gpiod_set_value_cansleep(ks->gpio, 1);
1224 	regulator_disable(ks->vdd_reg);
1225 err_reg:
1226 	regulator_disable(ks->vdd_io);
1227 err_reg_io:
1228 	return ret;
1229 }
1230 EXPORT_SYMBOL_GPL(ks8851_probe_common);
1231 
1232 void ks8851_remove_common(struct device *dev)
1233 {
1234 	struct ks8851_net *priv = dev_get_drvdata(dev);
1235 
1236 	ks8851_unregister_mdiobus(priv);
1237 
1238 	if (netif_msg_drv(priv))
1239 		dev_info(dev, "remove\n");
1240 
1241 	unregister_netdev(priv->netdev);
1242 	if (priv->gpio)
1243 		gpiod_set_value_cansleep(priv->gpio, 1);
1244 	regulator_disable(priv->vdd_reg);
1245 	regulator_disable(priv->vdd_io);
1246 }
1247 EXPORT_SYMBOL_GPL(ks8851_remove_common);
1248 
1249 MODULE_DESCRIPTION("KS8851 Network driver");
1250 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
1251 MODULE_LICENSE("GPL");
1252