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/regulator/consumer.h>
21 
22 #include <linux/gpio.h>
23 #include <linux/of_gpio.h>
24 #include <linux/of_mdio.h>
25 #include <linux/of_net.h>
26 
27 #include "ks8851.h"
28 
29 /**
30  * ks8851_lock - register access lock
31  * @ks: The chip state
32  * @flags: Spinlock flags
33  *
34  * Claim chip register access lock
35  */
36 static void ks8851_lock(struct ks8851_net *ks, unsigned long *flags)
37 {
38 	ks->lock(ks, flags);
39 }
40 
41 /**
42  * ks8851_unlock - register access unlock
43  * @ks: The chip state
44  * @flags: Spinlock flags
45  *
46  * Release chip register access lock
47  */
48 static void ks8851_unlock(struct ks8851_net *ks, unsigned long *flags)
49 {
50 	ks->unlock(ks, flags);
51 }
52 
53 /**
54  * ks8851_wrreg16 - write 16bit register value to chip
55  * @ks: The chip state
56  * @reg: The register address
57  * @val: The value to write
58  *
59  * Issue a write to put the value @val into the register specified in @reg.
60  */
61 static void ks8851_wrreg16(struct ks8851_net *ks, unsigned int reg,
62 			   unsigned int val)
63 {
64 	ks->wrreg16(ks, reg, val);
65 }
66 
67 /**
68  * ks8851_rdreg16 - read 16 bit register from device
69  * @ks: The chip information
70  * @reg: The register address
71  *
72  * Read a 16bit register from the chip, returning the result
73  */
74 static unsigned int ks8851_rdreg16(struct ks8851_net *ks,
75 				   unsigned int reg)
76 {
77 	return ks->rdreg16(ks, reg);
78 }
79 
80 /**
81  * ks8851_soft_reset - issue one of the soft reset to the device
82  * @ks: The device state.
83  * @op: The bit(s) to set in the GRR
84  *
85  * Issue the relevant soft-reset command to the device's GRR register
86  * specified by @op.
87  *
88  * Note, the delays are in there as a caution to ensure that the reset
89  * has time to take effect and then complete. Since the datasheet does
90  * not currently specify the exact sequence, we have chosen something
91  * that seems to work with our device.
92  */
93 static void ks8851_soft_reset(struct ks8851_net *ks, unsigned op)
94 {
95 	ks8851_wrreg16(ks, KS_GRR, op);
96 	mdelay(1);	/* wait a short time to effect reset */
97 	ks8851_wrreg16(ks, KS_GRR, 0);
98 	mdelay(1);	/* wait for condition to clear */
99 }
100 
101 /**
102  * ks8851_set_powermode - set power mode of the device
103  * @ks: The device state
104  * @pwrmode: The power mode value to write to KS_PMECR.
105  *
106  * Change the power mode of the chip.
107  */
108 static void ks8851_set_powermode(struct ks8851_net *ks, unsigned pwrmode)
109 {
110 	unsigned pmecr;
111 
112 	netif_dbg(ks, hw, ks->netdev, "setting power mode %d\n", pwrmode);
113 
114 	pmecr = ks8851_rdreg16(ks, KS_PMECR);
115 	pmecr &= ~PMECR_PM_MASK;
116 	pmecr |= pwrmode;
117 
118 	ks8851_wrreg16(ks, KS_PMECR, pmecr);
119 }
120 
121 /**
122  * ks8851_write_mac_addr - write mac address to device registers
123  * @dev: The network device
124  *
125  * Update the KS8851 MAC address registers from the address in @dev.
126  *
127  * This call assumes that the chip is not running, so there is no need to
128  * shutdown the RXQ process whilst setting this.
129 */
130 static int ks8851_write_mac_addr(struct net_device *dev)
131 {
132 	struct ks8851_net *ks = netdev_priv(dev);
133 	unsigned long flags;
134 	u16 val;
135 	int i;
136 
137 	ks8851_lock(ks, &flags);
138 
139 	/*
140 	 * Wake up chip in case it was powered off when stopped; otherwise,
141 	 * the first write to the MAC address does not take effect.
142 	 */
143 	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
144 
145 	for (i = 0; i < ETH_ALEN; i += 2) {
146 		val = (dev->dev_addr[i] << 8) | dev->dev_addr[i + 1];
147 		ks8851_wrreg16(ks, KS_MAR(i), val);
148 	}
149 
150 	if (!netif_running(dev))
151 		ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
152 
153 	ks8851_unlock(ks, &flags);
154 
155 	return 0;
156 }
157 
158 /**
159  * ks8851_read_mac_addr - read mac address from device registers
160  * @dev: The network device
161  *
162  * Update our copy of the KS8851 MAC address from the registers of @dev.
163 */
164 static void ks8851_read_mac_addr(struct net_device *dev)
165 {
166 	struct ks8851_net *ks = netdev_priv(dev);
167 	unsigned long flags;
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 		dev->dev_addr[i] = reg >> 8;
176 		dev->dev_addr[i + 1] = reg & 0xff;
177 	}
178 
179 	ks8851_unlock(ks, &flags);
180 }
181 
182 /**
183  * ks8851_init_mac - initialise the mac address
184  * @ks: The device structure
185  * @np: The device node pointer
186  *
187  * Get or create the initial mac address for the device and then set that
188  * into the station address register. A mac address supplied in the device
189  * tree takes precedence. Otherwise, if there is an EEPROM present, then
190  * we try that. If no valid mac address is found we use eth_random_addr()
191  * to create a new one.
192  */
193 static void ks8851_init_mac(struct ks8851_net *ks, struct device_node *np)
194 {
195 	struct net_device *dev = ks->netdev;
196 	int ret;
197 
198 	ret = of_get_mac_address(np, dev->dev_addr);
199 	if (!ret) {
200 		ks8851_write_mac_addr(dev);
201 		return;
202 	}
203 
204 	if (ks->rc_ccr & CCR_EEPROM) {
205 		ks8851_read_mac_addr(dev);
206 		if (is_valid_ether_addr(dev->dev_addr))
207 			return;
208 
209 		netdev_err(ks->netdev, "invalid mac address read %pM\n",
210 				dev->dev_addr);
211 	}
212 
213 	eth_hw_addr_random(dev);
214 	ks8851_write_mac_addr(dev);
215 }
216 
217 /**
218  * ks8851_dbg_dumpkkt - dump initial packet contents to debug
219  * @ks: The device state
220  * @rxpkt: The data for the received packet
221  *
222  * Dump the initial data from the packet to dev_dbg().
223  */
224 static void ks8851_dbg_dumpkkt(struct ks8851_net *ks, u8 *rxpkt)
225 {
226 	netdev_dbg(ks->netdev,
227 		   "pkt %02x%02x%02x%02x %02x%02x%02x%02x %02x%02x%02x%02x\n",
228 		   rxpkt[4], rxpkt[5], rxpkt[6], rxpkt[7],
229 		   rxpkt[8], rxpkt[9], rxpkt[10], rxpkt[11],
230 		   rxpkt[12], rxpkt[13], rxpkt[14], rxpkt[15]);
231 }
232 
233 /**
234  * ks8851_rx_skb - receive skbuff
235  * @ks: The device state.
236  * @skb: The skbuff
237  */
238 static void ks8851_rx_skb(struct ks8851_net *ks, struct sk_buff *skb)
239 {
240 	ks->rx_skb(ks, skb);
241 }
242 
243 /**
244  * ks8851_rx_pkts - receive packets from the host
245  * @ks: The device information.
246  *
247  * This is called from the IRQ work queue when the system detects that there
248  * are packets in the receive queue. Find out how many packets there are and
249  * read them from the FIFO.
250  */
251 static void ks8851_rx_pkts(struct ks8851_net *ks)
252 {
253 	struct sk_buff *skb;
254 	unsigned rxfc;
255 	unsigned rxlen;
256 	unsigned rxstat;
257 	u8 *rxpkt;
258 
259 	rxfc = (ks8851_rdreg16(ks, KS_RXFCTR) >> 8) & 0xff;
260 
261 	netif_dbg(ks, rx_status, ks->netdev,
262 		  "%s: %d packets\n", __func__, rxfc);
263 
264 	/* Currently we're issuing a read per packet, but we could possibly
265 	 * improve the code by issuing a single read, getting the receive
266 	 * header, allocating the packet and then reading the packet data
267 	 * out in one go.
268 	 *
269 	 * This form of operation would require us to hold the SPI bus'
270 	 * chipselect low during the entie transaction to avoid any
271 	 * reset to the data stream coming from the chip.
272 	 */
273 
274 	for (; rxfc != 0; rxfc--) {
275 		rxstat = ks8851_rdreg16(ks, KS_RXFHSR);
276 		rxlen = ks8851_rdreg16(ks, KS_RXFHBCR) & RXFHBCR_CNT_MASK;
277 
278 		netif_dbg(ks, rx_status, ks->netdev,
279 			  "rx: stat 0x%04x, len 0x%04x\n", rxstat, rxlen);
280 
281 		/* the length of the packet includes the 32bit CRC */
282 
283 		/* set dma read address */
284 		ks8851_wrreg16(ks, KS_RXFDPR, RXFDPR_RXFPAI | 0x00);
285 
286 		/* start DMA access */
287 		ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA);
288 
289 		if (rxlen > 4) {
290 			unsigned int rxalign;
291 
292 			rxlen -= 4;
293 			rxalign = ALIGN(rxlen, 4);
294 			skb = netdev_alloc_skb_ip_align(ks->netdev, rxalign);
295 			if (skb) {
296 
297 				/* 4 bytes of status header + 4 bytes of
298 				 * garbage: we put them before ethernet
299 				 * header, so that they are copied,
300 				 * but ignored.
301 				 */
302 
303 				rxpkt = skb_put(skb, rxlen) - 8;
304 
305 				ks->rdfifo(ks, rxpkt, rxalign + 8);
306 
307 				if (netif_msg_pktdata(ks))
308 					ks8851_dbg_dumpkkt(ks, rxpkt);
309 
310 				skb->protocol = eth_type_trans(skb, ks->netdev);
311 				ks8851_rx_skb(ks, skb);
312 
313 				ks->netdev->stats.rx_packets++;
314 				ks->netdev->stats.rx_bytes += rxlen;
315 			}
316 		}
317 
318 		/* end DMA access and dequeue packet */
319 		ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_RRXEF);
320 	}
321 }
322 
323 /**
324  * ks8851_irq - IRQ handler for dealing with interrupt requests
325  * @irq: IRQ number
326  * @_ks: cookie
327  *
328  * This handler is invoked when the IRQ line asserts to find out what happened.
329  * As we cannot allow ourselves to sleep in HARDIRQ context, this handler runs
330  * in thread context.
331  *
332  * Read the interrupt status, work out what needs to be done and then clear
333  * any of the interrupts that are not needed.
334  */
335 static irqreturn_t ks8851_irq(int irq, void *_ks)
336 {
337 	struct ks8851_net *ks = _ks;
338 	unsigned handled = 0;
339 	unsigned long flags;
340 	unsigned int status;
341 
342 	ks8851_lock(ks, &flags);
343 
344 	status = ks8851_rdreg16(ks, KS_ISR);
345 
346 	netif_dbg(ks, intr, ks->netdev,
347 		  "%s: status 0x%04x\n", __func__, status);
348 
349 	if (status & IRQ_LCI)
350 		handled |= IRQ_LCI;
351 
352 	if (status & IRQ_LDI) {
353 		u16 pmecr = ks8851_rdreg16(ks, KS_PMECR);
354 		pmecr &= ~PMECR_WKEVT_MASK;
355 		ks8851_wrreg16(ks, KS_PMECR, pmecr | PMECR_WKEVT_LINK);
356 
357 		handled |= IRQ_LDI;
358 	}
359 
360 	if (status & IRQ_RXPSI)
361 		handled |= IRQ_RXPSI;
362 
363 	if (status & IRQ_TXI) {
364 		handled |= IRQ_TXI;
365 
366 		/* no lock here, tx queue should have been stopped */
367 
368 		/* update our idea of how much tx space is available to the
369 		 * system */
370 		ks->tx_space = ks8851_rdreg16(ks, KS_TXMIR);
371 
372 		netif_dbg(ks, intr, ks->netdev,
373 			  "%s: txspace %d\n", __func__, ks->tx_space);
374 	}
375 
376 	if (status & IRQ_RXI)
377 		handled |= IRQ_RXI;
378 
379 	if (status & IRQ_SPIBEI) {
380 		netdev_err(ks->netdev, "%s: spi bus error\n", __func__);
381 		handled |= IRQ_SPIBEI;
382 	}
383 
384 	ks8851_wrreg16(ks, KS_ISR, handled);
385 
386 	if (status & IRQ_RXI) {
387 		/* the datasheet says to disable the rx interrupt during
388 		 * packet read-out, however we're masking the interrupt
389 		 * from the device so do not bother masking just the RX
390 		 * from the device. */
391 
392 		ks8851_rx_pkts(ks);
393 	}
394 
395 	/* if something stopped the rx process, probably due to wanting
396 	 * to change the rx settings, then do something about restarting
397 	 * it. */
398 	if (status & IRQ_RXPSI) {
399 		struct ks8851_rxctrl *rxc = &ks->rxctrl;
400 
401 		/* update the multicast hash table */
402 		ks8851_wrreg16(ks, KS_MAHTR0, rxc->mchash[0]);
403 		ks8851_wrreg16(ks, KS_MAHTR1, rxc->mchash[1]);
404 		ks8851_wrreg16(ks, KS_MAHTR2, rxc->mchash[2]);
405 		ks8851_wrreg16(ks, KS_MAHTR3, rxc->mchash[3]);
406 
407 		ks8851_wrreg16(ks, KS_RXCR2, rxc->rxcr2);
408 		ks8851_wrreg16(ks, KS_RXCR1, rxc->rxcr1);
409 	}
410 
411 	ks8851_unlock(ks, &flags);
412 
413 	if (status & IRQ_LCI)
414 		mii_check_link(&ks->mii);
415 
416 	if (status & IRQ_TXI)
417 		netif_wake_queue(ks->netdev);
418 
419 	return IRQ_HANDLED;
420 }
421 
422 /**
423  * ks8851_flush_tx_work - flush outstanding TX work
424  * @ks: The device state
425  */
426 static void ks8851_flush_tx_work(struct ks8851_net *ks)
427 {
428 	if (ks->flush_tx_work)
429 		ks->flush_tx_work(ks);
430 }
431 
432 /**
433  * ks8851_net_open - open network device
434  * @dev: The network device being opened.
435  *
436  * Called when the network device is marked active, such as a user executing
437  * 'ifconfig up' on the device.
438  */
439 static int ks8851_net_open(struct net_device *dev)
440 {
441 	struct ks8851_net *ks = netdev_priv(dev);
442 	unsigned long flags;
443 	int ret;
444 
445 	ret = request_threaded_irq(dev->irq, NULL, ks8851_irq,
446 				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
447 				   dev->name, ks);
448 	if (ret < 0) {
449 		netdev_err(dev, "failed to get irq\n");
450 		return ret;
451 	}
452 
453 	/* lock the card, even if we may not actually be doing anything
454 	 * else at the moment */
455 	ks8851_lock(ks, &flags);
456 
457 	netif_dbg(ks, ifup, ks->netdev, "opening\n");
458 
459 	/* bring chip out of any power saving mode it was in */
460 	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
461 
462 	/* issue a soft reset to the RX/TX QMU to put it into a known
463 	 * state. */
464 	ks8851_soft_reset(ks, GRR_QMU);
465 
466 	/* setup transmission parameters */
467 
468 	ks8851_wrreg16(ks, KS_TXCR, (TXCR_TXE | /* enable transmit process */
469 				     TXCR_TXPE | /* pad to min length */
470 				     TXCR_TXCRC | /* add CRC */
471 				     TXCR_TXFCE)); /* enable flow control */
472 
473 	/* auto-increment tx data, reset tx pointer */
474 	ks8851_wrreg16(ks, KS_TXFDPR, TXFDPR_TXFPAI);
475 
476 	/* setup receiver control */
477 
478 	ks8851_wrreg16(ks, KS_RXCR1, (RXCR1_RXPAFMA | /*  from mac filter */
479 				      RXCR1_RXFCE | /* enable flow control */
480 				      RXCR1_RXBE | /* broadcast enable */
481 				      RXCR1_RXUE | /* unicast enable */
482 				      RXCR1_RXE)); /* enable rx block */
483 
484 	/* transfer entire frames out in one go */
485 	ks8851_wrreg16(ks, KS_RXCR2, RXCR2_SRDBL_FRAME);
486 
487 	/* set receive counter timeouts */
488 	ks8851_wrreg16(ks, KS_RXDTTR, 1000); /* 1ms after first frame to IRQ */
489 	ks8851_wrreg16(ks, KS_RXDBCTR, 4096); /* >4Kbytes in buffer to IRQ */
490 	ks8851_wrreg16(ks, KS_RXFCTR, 10);  /* 10 frames to IRQ */
491 
492 	ks->rc_rxqcr = (RXQCR_RXFCTE |  /* IRQ on frame count exceeded */
493 			RXQCR_RXDBCTE | /* IRQ on byte count exceeded */
494 			RXQCR_RXDTTE);  /* IRQ on time exceeded */
495 
496 	ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr);
497 
498 	/* clear then enable interrupts */
499 	ks8851_wrreg16(ks, KS_ISR, ks->rc_ier);
500 	ks8851_wrreg16(ks, KS_IER, ks->rc_ier);
501 
502 	netif_start_queue(ks->netdev);
503 
504 	netif_dbg(ks, ifup, ks->netdev, "network device up\n");
505 
506 	ks8851_unlock(ks, &flags);
507 	mii_check_link(&ks->mii);
508 	return 0;
509 }
510 
511 /**
512  * ks8851_net_stop - close network device
513  * @dev: The device being closed.
514  *
515  * Called to close down a network device which has been active. Cancell any
516  * work, shutdown the RX and TX process and then place the chip into a low
517  * power state whilst it is not being used.
518  */
519 static int ks8851_net_stop(struct net_device *dev)
520 {
521 	struct ks8851_net *ks = netdev_priv(dev);
522 	unsigned long flags;
523 
524 	netif_info(ks, ifdown, dev, "shutting down\n");
525 
526 	netif_stop_queue(dev);
527 
528 	ks8851_lock(ks, &flags);
529 	/* turn off the IRQs and ack any outstanding */
530 	ks8851_wrreg16(ks, KS_IER, 0x0000);
531 	ks8851_wrreg16(ks, KS_ISR, 0xffff);
532 	ks8851_unlock(ks, &flags);
533 
534 	/* stop any outstanding work */
535 	ks8851_flush_tx_work(ks);
536 	flush_work(&ks->rxctrl_work);
537 
538 	ks8851_lock(ks, &flags);
539 	/* shutdown RX process */
540 	ks8851_wrreg16(ks, KS_RXCR1, 0x0000);
541 
542 	/* shutdown TX process */
543 	ks8851_wrreg16(ks, KS_TXCR, 0x0000);
544 
545 	/* set powermode to soft power down to save power */
546 	ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
547 	ks8851_unlock(ks, &flags);
548 
549 	/* ensure any queued tx buffers are dumped */
550 	while (!skb_queue_empty(&ks->txq)) {
551 		struct sk_buff *txb = skb_dequeue(&ks->txq);
552 
553 		netif_dbg(ks, ifdown, ks->netdev,
554 			  "%s: freeing txb %p\n", __func__, txb);
555 
556 		dev_kfree_skb(txb);
557 	}
558 
559 	free_irq(dev->irq, ks);
560 
561 	return 0;
562 }
563 
564 /**
565  * ks8851_start_xmit - transmit packet
566  * @skb: The buffer to transmit
567  * @dev: The device used to transmit the packet.
568  *
569  * Called by the network layer to transmit the @skb. Queue the packet for
570  * the device and schedule the necessary work to transmit the packet when
571  * it is free.
572  *
573  * We do this to firstly avoid sleeping with the network device locked,
574  * and secondly so we can round up more than one packet to transmit which
575  * means we can try and avoid generating too many transmit done interrupts.
576  */
577 static netdev_tx_t ks8851_start_xmit(struct sk_buff *skb,
578 				     struct net_device *dev)
579 {
580 	struct ks8851_net *ks = netdev_priv(dev);
581 
582 	return ks->start_xmit(skb, dev);
583 }
584 
585 /**
586  * ks8851_rxctrl_work - work handler to change rx mode
587  * @work: The work structure this belongs to.
588  *
589  * Lock the device and issue the necessary changes to the receive mode from
590  * the network device layer. This is done so that we can do this without
591  * having to sleep whilst holding the network device lock.
592  *
593  * Since the recommendation from Micrel is that the RXQ is shutdown whilst the
594  * receive parameters are programmed, we issue a write to disable the RXQ and
595  * then wait for the interrupt handler to be triggered once the RXQ shutdown is
596  * complete. The interrupt handler then writes the new values into the chip.
597  */
598 static void ks8851_rxctrl_work(struct work_struct *work)
599 {
600 	struct ks8851_net *ks = container_of(work, struct ks8851_net, rxctrl_work);
601 	unsigned long flags;
602 
603 	ks8851_lock(ks, &flags);
604 
605 	/* need to shutdown RXQ before modifying filter parameters */
606 	ks8851_wrreg16(ks, KS_RXCR1, 0x00);
607 
608 	ks8851_unlock(ks, &flags);
609 }
610 
611 static void ks8851_set_rx_mode(struct net_device *dev)
612 {
613 	struct ks8851_net *ks = netdev_priv(dev);
614 	struct ks8851_rxctrl rxctrl;
615 
616 	memset(&rxctrl, 0, sizeof(rxctrl));
617 
618 	if (dev->flags & IFF_PROMISC) {
619 		/* interface to receive everything */
620 
621 		rxctrl.rxcr1 = RXCR1_RXAE | RXCR1_RXINVF;
622 	} else if (dev->flags & IFF_ALLMULTI) {
623 		/* accept all multicast packets */
624 
625 		rxctrl.rxcr1 = (RXCR1_RXME | RXCR1_RXAE |
626 				RXCR1_RXPAFMA | RXCR1_RXMAFMA);
627 	} else if (dev->flags & IFF_MULTICAST && !netdev_mc_empty(dev)) {
628 		struct netdev_hw_addr *ha;
629 		u32 crc;
630 
631 		/* accept some multicast */
632 
633 		netdev_for_each_mc_addr(ha, dev) {
634 			crc = ether_crc(ETH_ALEN, ha->addr);
635 			crc >>= (32 - 6);  /* get top six bits */
636 
637 			rxctrl.mchash[crc >> 4] |= (1 << (crc & 0xf));
638 		}
639 
640 		rxctrl.rxcr1 = RXCR1_RXME | RXCR1_RXPAFMA;
641 	} else {
642 		/* just accept broadcast / unicast */
643 		rxctrl.rxcr1 = RXCR1_RXPAFMA;
644 	}
645 
646 	rxctrl.rxcr1 |= (RXCR1_RXUE | /* unicast enable */
647 			 RXCR1_RXBE | /* broadcast enable */
648 			 RXCR1_RXE | /* RX process enable */
649 			 RXCR1_RXFCE); /* enable flow control */
650 
651 	rxctrl.rxcr2 |= RXCR2_SRDBL_FRAME;
652 
653 	/* schedule work to do the actual set of the data if needed */
654 
655 	spin_lock(&ks->statelock);
656 
657 	if (memcmp(&rxctrl, &ks->rxctrl, sizeof(rxctrl)) != 0) {
658 		memcpy(&ks->rxctrl, &rxctrl, sizeof(ks->rxctrl));
659 		schedule_work(&ks->rxctrl_work);
660 	}
661 
662 	spin_unlock(&ks->statelock);
663 }
664 
665 static int ks8851_set_mac_address(struct net_device *dev, void *addr)
666 {
667 	struct sockaddr *sa = addr;
668 
669 	if (netif_running(dev))
670 		return -EBUSY;
671 
672 	if (!is_valid_ether_addr(sa->sa_data))
673 		return -EADDRNOTAVAIL;
674 
675 	memcpy(dev->dev_addr, sa->sa_data, ETH_ALEN);
676 	return ks8851_write_mac_addr(dev);
677 }
678 
679 static int ks8851_net_ioctl(struct net_device *dev, struct ifreq *req, int cmd)
680 {
681 	struct ks8851_net *ks = netdev_priv(dev);
682 
683 	if (!netif_running(dev))
684 		return -EINVAL;
685 
686 	return generic_mii_ioctl(&ks->mii, if_mii(req), cmd, NULL);
687 }
688 
689 static const struct net_device_ops ks8851_netdev_ops = {
690 	.ndo_open		= ks8851_net_open,
691 	.ndo_stop		= ks8851_net_stop,
692 	.ndo_do_ioctl		= ks8851_net_ioctl,
693 	.ndo_start_xmit		= ks8851_start_xmit,
694 	.ndo_set_mac_address	= ks8851_set_mac_address,
695 	.ndo_set_rx_mode	= ks8851_set_rx_mode,
696 	.ndo_validate_addr	= eth_validate_addr,
697 };
698 
699 /* ethtool support */
700 
701 static void ks8851_get_drvinfo(struct net_device *dev,
702 			       struct ethtool_drvinfo *di)
703 {
704 	strlcpy(di->driver, "KS8851", sizeof(di->driver));
705 	strlcpy(di->version, "1.00", sizeof(di->version));
706 	strlcpy(di->bus_info, dev_name(dev->dev.parent), sizeof(di->bus_info));
707 }
708 
709 static u32 ks8851_get_msglevel(struct net_device *dev)
710 {
711 	struct ks8851_net *ks = netdev_priv(dev);
712 	return ks->msg_enable;
713 }
714 
715 static void ks8851_set_msglevel(struct net_device *dev, u32 to)
716 {
717 	struct ks8851_net *ks = netdev_priv(dev);
718 	ks->msg_enable = to;
719 }
720 
721 static int ks8851_get_link_ksettings(struct net_device *dev,
722 				     struct ethtool_link_ksettings *cmd)
723 {
724 	struct ks8851_net *ks = netdev_priv(dev);
725 
726 	mii_ethtool_get_link_ksettings(&ks->mii, cmd);
727 
728 	return 0;
729 }
730 
731 static int ks8851_set_link_ksettings(struct net_device *dev,
732 				     const struct ethtool_link_ksettings *cmd)
733 {
734 	struct ks8851_net *ks = netdev_priv(dev);
735 	return mii_ethtool_set_link_ksettings(&ks->mii, cmd);
736 }
737 
738 static u32 ks8851_get_link(struct net_device *dev)
739 {
740 	struct ks8851_net *ks = netdev_priv(dev);
741 	return mii_link_ok(&ks->mii);
742 }
743 
744 static int ks8851_nway_reset(struct net_device *dev)
745 {
746 	struct ks8851_net *ks = netdev_priv(dev);
747 	return mii_nway_restart(&ks->mii);
748 }
749 
750 /* EEPROM support */
751 
752 static void ks8851_eeprom_regread(struct eeprom_93cx6 *ee)
753 {
754 	struct ks8851_net *ks = ee->data;
755 	unsigned val;
756 
757 	val = ks8851_rdreg16(ks, KS_EEPCR);
758 
759 	ee->reg_data_out = (val & EEPCR_EESB) ? 1 : 0;
760 	ee->reg_data_clock = (val & EEPCR_EESCK) ? 1 : 0;
761 	ee->reg_chip_select = (val & EEPCR_EECS) ? 1 : 0;
762 }
763 
764 static void ks8851_eeprom_regwrite(struct eeprom_93cx6 *ee)
765 {
766 	struct ks8851_net *ks = ee->data;
767 	unsigned val = EEPCR_EESA;	/* default - eeprom access on */
768 
769 	if (ee->drive_data)
770 		val |= EEPCR_EESRWA;
771 	if (ee->reg_data_in)
772 		val |= EEPCR_EEDO;
773 	if (ee->reg_data_clock)
774 		val |= EEPCR_EESCK;
775 	if (ee->reg_chip_select)
776 		val |= EEPCR_EECS;
777 
778 	ks8851_wrreg16(ks, KS_EEPCR, val);
779 }
780 
781 /**
782  * ks8851_eeprom_claim - claim device EEPROM and activate the interface
783  * @ks: The network device state.
784  *
785  * Check for the presence of an EEPROM, and then activate software access
786  * to the device.
787  */
788 static int ks8851_eeprom_claim(struct ks8851_net *ks)
789 {
790 	/* start with clock low, cs high */
791 	ks8851_wrreg16(ks, KS_EEPCR, EEPCR_EESA | EEPCR_EECS);
792 	return 0;
793 }
794 
795 /**
796  * ks8851_eeprom_release - release the EEPROM interface
797  * @ks: The device state
798  *
799  * Release the software access to the device EEPROM
800  */
801 static void ks8851_eeprom_release(struct ks8851_net *ks)
802 {
803 	unsigned val = ks8851_rdreg16(ks, KS_EEPCR);
804 
805 	ks8851_wrreg16(ks, KS_EEPCR, val & ~EEPCR_EESA);
806 }
807 
808 #define KS_EEPROM_MAGIC (0x00008851)
809 
810 static int ks8851_set_eeprom(struct net_device *dev,
811 			     struct ethtool_eeprom *ee, u8 *data)
812 {
813 	struct ks8851_net *ks = netdev_priv(dev);
814 	int offset = ee->offset;
815 	unsigned long flags;
816 	int len = ee->len;
817 	u16 tmp;
818 
819 	/* currently only support byte writing */
820 	if (len != 1)
821 		return -EINVAL;
822 
823 	if (ee->magic != KS_EEPROM_MAGIC)
824 		return -EINVAL;
825 
826 	if (!(ks->rc_ccr & CCR_EEPROM))
827 		return -ENOENT;
828 
829 	ks8851_lock(ks, &flags);
830 
831 	ks8851_eeprom_claim(ks);
832 
833 	eeprom_93cx6_wren(&ks->eeprom, true);
834 
835 	/* ethtool currently only supports writing bytes, which means
836 	 * we have to read/modify/write our 16bit EEPROMs */
837 
838 	eeprom_93cx6_read(&ks->eeprom, offset/2, &tmp);
839 
840 	if (offset & 1) {
841 		tmp &= 0xff;
842 		tmp |= *data << 8;
843 	} else {
844 		tmp &= 0xff00;
845 		tmp |= *data;
846 	}
847 
848 	eeprom_93cx6_write(&ks->eeprom, offset/2, tmp);
849 	eeprom_93cx6_wren(&ks->eeprom, false);
850 
851 	ks8851_eeprom_release(ks);
852 	ks8851_unlock(ks, &flags);
853 
854 	return 0;
855 }
856 
857 static int ks8851_get_eeprom(struct net_device *dev,
858 			     struct ethtool_eeprom *ee, u8 *data)
859 {
860 	struct ks8851_net *ks = netdev_priv(dev);
861 	int offset = ee->offset;
862 	unsigned long flags;
863 	int len = ee->len;
864 
865 	/* must be 2 byte aligned */
866 	if (len & 1 || offset & 1)
867 		return -EINVAL;
868 
869 	if (!(ks->rc_ccr & CCR_EEPROM))
870 		return -ENOENT;
871 
872 	ks8851_lock(ks, &flags);
873 
874 	ks8851_eeprom_claim(ks);
875 
876 	ee->magic = KS_EEPROM_MAGIC;
877 
878 	eeprom_93cx6_multiread(&ks->eeprom, offset/2, (__le16 *)data, len/2);
879 	ks8851_eeprom_release(ks);
880 	ks8851_unlock(ks, &flags);
881 
882 	return 0;
883 }
884 
885 static int ks8851_get_eeprom_len(struct net_device *dev)
886 {
887 	struct ks8851_net *ks = netdev_priv(dev);
888 
889 	/* currently, we assume it is an 93C46 attached, so return 128 */
890 	return ks->rc_ccr & CCR_EEPROM ? 128 : 0;
891 }
892 
893 static const struct ethtool_ops ks8851_ethtool_ops = {
894 	.get_drvinfo	= ks8851_get_drvinfo,
895 	.get_msglevel	= ks8851_get_msglevel,
896 	.set_msglevel	= ks8851_set_msglevel,
897 	.get_link	= ks8851_get_link,
898 	.nway_reset	= ks8851_nway_reset,
899 	.get_eeprom_len	= ks8851_get_eeprom_len,
900 	.get_eeprom	= ks8851_get_eeprom,
901 	.set_eeprom	= ks8851_set_eeprom,
902 	.get_link_ksettings = ks8851_get_link_ksettings,
903 	.set_link_ksettings = ks8851_set_link_ksettings,
904 };
905 
906 /* MII interface controls */
907 
908 /**
909  * ks8851_phy_reg - convert MII register into a KS8851 register
910  * @reg: MII register number.
911  *
912  * Return the KS8851 register number for the corresponding MII PHY register
913  * if possible. Return zero if the MII register has no direct mapping to the
914  * KS8851 register set.
915  */
916 static int ks8851_phy_reg(int reg)
917 {
918 	switch (reg) {
919 	case MII_BMCR:
920 		return KS_P1MBCR;
921 	case MII_BMSR:
922 		return KS_P1MBSR;
923 	case MII_PHYSID1:
924 		return KS_PHY1ILR;
925 	case MII_PHYSID2:
926 		return KS_PHY1IHR;
927 	case MII_ADVERTISE:
928 		return KS_P1ANAR;
929 	case MII_LPA:
930 		return KS_P1ANLPR;
931 	}
932 
933 	return -EOPNOTSUPP;
934 }
935 
936 static int ks8851_phy_read_common(struct net_device *dev, int phy_addr, int reg)
937 {
938 	struct ks8851_net *ks = netdev_priv(dev);
939 	unsigned long flags;
940 	int result;
941 	int ksreg;
942 
943 	ksreg = ks8851_phy_reg(reg);
944 	if (ksreg < 0)
945 		return ksreg;
946 
947 	ks8851_lock(ks, &flags);
948 	result = ks8851_rdreg16(ks, ksreg);
949 	ks8851_unlock(ks, &flags);
950 
951 	return result;
952 }
953 
954 /**
955  * ks8851_phy_read - MII interface PHY register read.
956  * @dev: The network device the PHY is on.
957  * @phy_addr: Address of PHY (ignored as we only have one)
958  * @reg: The register to read.
959  *
960  * This call reads data from the PHY register specified in @reg. Since the
961  * device does not support all the MII registers, the non-existent values
962  * are always returned as zero.
963  *
964  * We return zero for unsupported registers as the MII code does not check
965  * the value returned for any error status, and simply returns it to the
966  * caller. The mii-tool that the driver was tested with takes any -ve error
967  * as real PHY capabilities, thus displaying incorrect data to the user.
968  */
969 static int ks8851_phy_read(struct net_device *dev, int phy_addr, int reg)
970 {
971 	int ret;
972 
973 	ret = ks8851_phy_read_common(dev, phy_addr, reg);
974 	if (ret < 0)
975 		return 0x0;	/* no error return allowed, so use zero */
976 
977 	return ret;
978 }
979 
980 static void ks8851_phy_write(struct net_device *dev,
981 			     int phy, int reg, int value)
982 {
983 	struct ks8851_net *ks = netdev_priv(dev);
984 	unsigned long flags;
985 	int ksreg;
986 
987 	ksreg = ks8851_phy_reg(reg);
988 	if (ksreg >= 0) {
989 		ks8851_lock(ks, &flags);
990 		ks8851_wrreg16(ks, ksreg, value);
991 		ks8851_unlock(ks, &flags);
992 	}
993 }
994 
995 static int ks8851_mdio_read(struct mii_bus *bus, int phy_id, int reg)
996 {
997 	struct ks8851_net *ks = bus->priv;
998 
999 	if (phy_id != 0)
1000 		return -EOPNOTSUPP;
1001 
1002 	/* KS8851 PHY ID registers are swapped in HW, swap them back. */
1003 	if (reg == MII_PHYSID1)
1004 		reg = MII_PHYSID2;
1005 	else if (reg == MII_PHYSID2)
1006 		reg = MII_PHYSID1;
1007 
1008 	return ks8851_phy_read_common(ks->netdev, phy_id, reg);
1009 }
1010 
1011 static int ks8851_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
1012 {
1013 	struct ks8851_net *ks = bus->priv;
1014 
1015 	ks8851_phy_write(ks->netdev, phy_id, reg, val);
1016 	return 0;
1017 }
1018 
1019 /**
1020  * ks8851_read_selftest - read the selftest memory info.
1021  * @ks: The device state
1022  *
1023  * Read and check the TX/RX memory selftest information.
1024  */
1025 static int ks8851_read_selftest(struct ks8851_net *ks)
1026 {
1027 	unsigned both_done = MBIR_TXMBF | MBIR_RXMBF;
1028 	int ret = 0;
1029 	unsigned rd;
1030 
1031 	rd = ks8851_rdreg16(ks, KS_MBIR);
1032 
1033 	if ((rd & both_done) != both_done) {
1034 		netdev_warn(ks->netdev, "Memory selftest not finished\n");
1035 		return 0;
1036 	}
1037 
1038 	if (rd & MBIR_TXMBFA) {
1039 		netdev_err(ks->netdev, "TX memory selftest fail\n");
1040 		ret |= 1;
1041 	}
1042 
1043 	if (rd & MBIR_RXMBFA) {
1044 		netdev_err(ks->netdev, "RX memory selftest fail\n");
1045 		ret |= 2;
1046 	}
1047 
1048 	return 0;
1049 }
1050 
1051 /* driver bus management functions */
1052 
1053 #ifdef CONFIG_PM_SLEEP
1054 
1055 int ks8851_suspend(struct device *dev)
1056 {
1057 	struct ks8851_net *ks = dev_get_drvdata(dev);
1058 	struct net_device *netdev = ks->netdev;
1059 
1060 	if (netif_running(netdev)) {
1061 		netif_device_detach(netdev);
1062 		ks8851_net_stop(netdev);
1063 	}
1064 
1065 	return 0;
1066 }
1067 
1068 int ks8851_resume(struct device *dev)
1069 {
1070 	struct ks8851_net *ks = dev_get_drvdata(dev);
1071 	struct net_device *netdev = ks->netdev;
1072 
1073 	if (netif_running(netdev)) {
1074 		ks8851_net_open(netdev);
1075 		netif_device_attach(netdev);
1076 	}
1077 
1078 	return 0;
1079 }
1080 #endif
1081 
1082 static int ks8851_register_mdiobus(struct ks8851_net *ks, struct device *dev)
1083 {
1084 	struct mii_bus *mii_bus;
1085 	int ret;
1086 
1087 	mii_bus = mdiobus_alloc();
1088 	if (!mii_bus)
1089 		return -ENOMEM;
1090 
1091 	mii_bus->name = "ks8851_eth_mii";
1092 	mii_bus->read = ks8851_mdio_read;
1093 	mii_bus->write = ks8851_mdio_write;
1094 	mii_bus->priv = ks;
1095 	mii_bus->parent = dev;
1096 	mii_bus->phy_mask = ~((u32)BIT(0));
1097 	snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
1098 
1099 	ret = mdiobus_register(mii_bus);
1100 	if (ret)
1101 		goto err_mdiobus_register;
1102 
1103 	ks->mii_bus = mii_bus;
1104 
1105 	return 0;
1106 
1107 err_mdiobus_register:
1108 	mdiobus_free(mii_bus);
1109 	return ret;
1110 }
1111 
1112 static void ks8851_unregister_mdiobus(struct ks8851_net *ks)
1113 {
1114 	mdiobus_unregister(ks->mii_bus);
1115 	mdiobus_free(ks->mii_bus);
1116 }
1117 
1118 int ks8851_probe_common(struct net_device *netdev, struct device *dev,
1119 			int msg_en)
1120 {
1121 	struct ks8851_net *ks = netdev_priv(netdev);
1122 	unsigned cider;
1123 	int gpio;
1124 	int ret;
1125 
1126 	ks->netdev = netdev;
1127 	ks->tx_space = 6144;
1128 
1129 	gpio = of_get_named_gpio_flags(dev->of_node, "reset-gpios", 0, NULL);
1130 	if (gpio == -EPROBE_DEFER)
1131 		return gpio;
1132 
1133 	ks->gpio = gpio;
1134 	if (gpio_is_valid(gpio)) {
1135 		ret = devm_gpio_request_one(dev, gpio,
1136 					    GPIOF_OUT_INIT_LOW, "ks8851_rst_n");
1137 		if (ret) {
1138 			dev_err(dev, "reset gpio request failed\n");
1139 			return ret;
1140 		}
1141 	}
1142 
1143 	ks->vdd_io = devm_regulator_get(dev, "vdd-io");
1144 	if (IS_ERR(ks->vdd_io)) {
1145 		ret = PTR_ERR(ks->vdd_io);
1146 		goto err_reg_io;
1147 	}
1148 
1149 	ret = regulator_enable(ks->vdd_io);
1150 	if (ret) {
1151 		dev_err(dev, "regulator vdd_io enable fail: %d\n", ret);
1152 		goto err_reg_io;
1153 	}
1154 
1155 	ks->vdd_reg = devm_regulator_get(dev, "vdd");
1156 	if (IS_ERR(ks->vdd_reg)) {
1157 		ret = PTR_ERR(ks->vdd_reg);
1158 		goto err_reg;
1159 	}
1160 
1161 	ret = regulator_enable(ks->vdd_reg);
1162 	if (ret) {
1163 		dev_err(dev, "regulator vdd enable fail: %d\n", ret);
1164 		goto err_reg;
1165 	}
1166 
1167 	if (gpio_is_valid(gpio)) {
1168 		usleep_range(10000, 11000);
1169 		gpio_set_value(gpio, 1);
1170 	}
1171 
1172 	spin_lock_init(&ks->statelock);
1173 
1174 	INIT_WORK(&ks->rxctrl_work, ks8851_rxctrl_work);
1175 
1176 	SET_NETDEV_DEV(netdev, dev);
1177 
1178 	/* setup EEPROM state */
1179 	ks->eeprom.data = ks;
1180 	ks->eeprom.width = PCI_EEPROM_WIDTH_93C46;
1181 	ks->eeprom.register_read = ks8851_eeprom_regread;
1182 	ks->eeprom.register_write = ks8851_eeprom_regwrite;
1183 
1184 	/* setup mii state */
1185 	ks->mii.dev		= netdev;
1186 	ks->mii.phy_id		= 1;
1187 	ks->mii.phy_id_mask	= 1;
1188 	ks->mii.reg_num_mask	= 0xf;
1189 	ks->mii.mdio_read	= ks8851_phy_read;
1190 	ks->mii.mdio_write	= ks8851_phy_write;
1191 
1192 	dev_info(dev, "message enable is %d\n", msg_en);
1193 
1194 	ret = ks8851_register_mdiobus(ks, dev);
1195 	if (ret)
1196 		goto err_mdio;
1197 
1198 	/* set the default message enable */
1199 	ks->msg_enable = netif_msg_init(msg_en, NETIF_MSG_DRV |
1200 						NETIF_MSG_PROBE |
1201 						NETIF_MSG_LINK);
1202 
1203 	skb_queue_head_init(&ks->txq);
1204 
1205 	netdev->ethtool_ops = &ks8851_ethtool_ops;
1206 
1207 	dev_set_drvdata(dev, ks);
1208 
1209 	netif_carrier_off(ks->netdev);
1210 	netdev->if_port = IF_PORT_100BASET;
1211 	netdev->netdev_ops = &ks8851_netdev_ops;
1212 
1213 	/* issue a global soft reset to reset the device. */
1214 	ks8851_soft_reset(ks, GRR_GSR);
1215 
1216 	/* simple check for a valid chip being connected to the bus */
1217 	cider = ks8851_rdreg16(ks, KS_CIDER);
1218 	if ((cider & ~CIDER_REV_MASK) != CIDER_ID) {
1219 		dev_err(dev, "failed to read device ID\n");
1220 		ret = -ENODEV;
1221 		goto err_id;
1222 	}
1223 
1224 	/* cache the contents of the CCR register for EEPROM, etc. */
1225 	ks->rc_ccr = ks8851_rdreg16(ks, KS_CCR);
1226 
1227 	ks8851_read_selftest(ks);
1228 	ks8851_init_mac(ks, dev->of_node);
1229 
1230 	ret = register_netdev(netdev);
1231 	if (ret) {
1232 		dev_err(dev, "failed to register network device\n");
1233 		goto err_id;
1234 	}
1235 
1236 	netdev_info(netdev, "revision %d, MAC %pM, IRQ %d, %s EEPROM\n",
1237 		    CIDER_REV_GET(cider), netdev->dev_addr, netdev->irq,
1238 		    ks->rc_ccr & CCR_EEPROM ? "has" : "no");
1239 
1240 	return 0;
1241 
1242 err_id:
1243 	ks8851_unregister_mdiobus(ks);
1244 err_mdio:
1245 	if (gpio_is_valid(gpio))
1246 		gpio_set_value(gpio, 0);
1247 	regulator_disable(ks->vdd_reg);
1248 err_reg:
1249 	regulator_disable(ks->vdd_io);
1250 err_reg_io:
1251 	return ret;
1252 }
1253 
1254 int ks8851_remove_common(struct device *dev)
1255 {
1256 	struct ks8851_net *priv = dev_get_drvdata(dev);
1257 
1258 	ks8851_unregister_mdiobus(priv);
1259 
1260 	if (netif_msg_drv(priv))
1261 		dev_info(dev, "remove\n");
1262 
1263 	unregister_netdev(priv->netdev);
1264 	if (gpio_is_valid(priv->gpio))
1265 		gpio_set_value(priv->gpio, 0);
1266 	regulator_disable(priv->vdd_reg);
1267 	regulator_disable(priv->vdd_io);
1268 
1269 	return 0;
1270 }
1271