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 	const u8 *mac_addr;
197 
198 	mac_addr = of_get_mac_address(np);
199 	if (!IS_ERR(mac_addr)) {
200 		ether_addr_copy(dev->dev_addr, mac_addr);
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_skb - receive skbuff
236  * @ks: The device state.
237  * @skb: The skbuff
238  */
239 static void ks8851_rx_skb(struct ks8851_net *ks, struct sk_buff *skb)
240 {
241 	ks->rx_skb(ks, skb);
242 }
243 
244 /**
245  * ks8851_rx_pkts - receive packets from the host
246  * @ks: The device information.
247  *
248  * This is called from the IRQ work queue when the system detects that there
249  * are packets in the receive queue. Find out how many packets there are and
250  * read them from the FIFO.
251  */
252 static void ks8851_rx_pkts(struct ks8851_net *ks)
253 {
254 	struct sk_buff *skb;
255 	unsigned rxfc;
256 	unsigned rxlen;
257 	unsigned rxstat;
258 	u8 *rxpkt;
259 
260 	rxfc = (ks8851_rdreg16(ks, KS_RXFCTR) >> 8) & 0xff;
261 
262 	netif_dbg(ks, rx_status, ks->netdev,
263 		  "%s: %d packets\n", __func__, rxfc);
264 
265 	/* Currently we're issuing a read per packet, but we could possibly
266 	 * improve the code by issuing a single read, getting the receive
267 	 * header, allocating the packet and then reading the packet data
268 	 * out in one go.
269 	 *
270 	 * This form of operation would require us to hold the SPI bus'
271 	 * chipselect low during the entie transaction to avoid any
272 	 * reset to the data stream coming from the chip.
273 	 */
274 
275 	for (; rxfc != 0; rxfc--) {
276 		rxstat = ks8851_rdreg16(ks, KS_RXFHSR);
277 		rxlen = ks8851_rdreg16(ks, KS_RXFHBCR) & RXFHBCR_CNT_MASK;
278 
279 		netif_dbg(ks, rx_status, ks->netdev,
280 			  "rx: stat 0x%04x, len 0x%04x\n", rxstat, rxlen);
281 
282 		/* the length of the packet includes the 32bit CRC */
283 
284 		/* set dma read address */
285 		ks8851_wrreg16(ks, KS_RXFDPR, RXFDPR_RXFPAI | 0x00);
286 
287 		/* start DMA access */
288 		ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA);
289 
290 		if (rxlen > 4) {
291 			unsigned int rxalign;
292 
293 			rxlen -= 4;
294 			rxalign = ALIGN(rxlen, 4);
295 			skb = netdev_alloc_skb_ip_align(ks->netdev, rxalign);
296 			if (skb) {
297 
298 				/* 4 bytes of status header + 4 bytes of
299 				 * garbage: we put them before ethernet
300 				 * header, so that they are copied,
301 				 * but ignored.
302 				 */
303 
304 				rxpkt = skb_put(skb, rxlen) - 8;
305 
306 				ks->rdfifo(ks, rxpkt, rxalign + 8);
307 
308 				if (netif_msg_pktdata(ks))
309 					ks8851_dbg_dumpkkt(ks, rxpkt);
310 
311 				skb->protocol = eth_type_trans(skb, ks->netdev);
312 				ks8851_rx_skb(ks, skb);
313 
314 				ks->netdev->stats.rx_packets++;
315 				ks->netdev->stats.rx_bytes += rxlen;
316 			}
317 		}
318 
319 		/* end DMA access and dequeue packet */
320 		ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_RRXEF);
321 	}
322 }
323 
324 /**
325  * ks8851_irq - IRQ handler for dealing with interrupt requests
326  * @irq: IRQ number
327  * @_ks: cookie
328  *
329  * This handler is invoked when the IRQ line asserts to find out what happened.
330  * As we cannot allow ourselves to sleep in HARDIRQ context, this handler runs
331  * in thread context.
332  *
333  * Read the interrupt status, work out what needs to be done and then clear
334  * any of the interrupts that are not needed.
335  */
336 static irqreturn_t ks8851_irq(int irq, void *_ks)
337 {
338 	struct ks8851_net *ks = _ks;
339 	unsigned handled = 0;
340 	unsigned long flags;
341 	unsigned int status;
342 
343 	ks8851_lock(ks, &flags);
344 
345 	status = ks8851_rdreg16(ks, KS_ISR);
346 
347 	netif_dbg(ks, intr, ks->netdev,
348 		  "%s: status 0x%04x\n", __func__, status);
349 
350 	if (status & IRQ_LCI)
351 		handled |= IRQ_LCI;
352 
353 	if (status & IRQ_LDI) {
354 		u16 pmecr = ks8851_rdreg16(ks, KS_PMECR);
355 		pmecr &= ~PMECR_WKEVT_MASK;
356 		ks8851_wrreg16(ks, KS_PMECR, pmecr | PMECR_WKEVT_LINK);
357 
358 		handled |= IRQ_LDI;
359 	}
360 
361 	if (status & IRQ_RXPSI)
362 		handled |= IRQ_RXPSI;
363 
364 	if (status & IRQ_TXI) {
365 		handled |= IRQ_TXI;
366 
367 		/* no lock here, tx queue should have been stopped */
368 
369 		/* update our idea of how much tx space is available to the
370 		 * system */
371 		ks->tx_space = ks8851_rdreg16(ks, KS_TXMIR);
372 
373 		netif_dbg(ks, intr, ks->netdev,
374 			  "%s: txspace %d\n", __func__, ks->tx_space);
375 	}
376 
377 	if (status & IRQ_RXI)
378 		handled |= IRQ_RXI;
379 
380 	if (status & IRQ_SPIBEI) {
381 		netdev_err(ks->netdev, "%s: spi bus error\n", __func__);
382 		handled |= IRQ_SPIBEI;
383 	}
384 
385 	ks8851_wrreg16(ks, KS_ISR, handled);
386 
387 	if (status & IRQ_RXI) {
388 		/* the datasheet says to disable the rx interrupt during
389 		 * packet read-out, however we're masking the interrupt
390 		 * from the device so do not bother masking just the RX
391 		 * from the device. */
392 
393 		ks8851_rx_pkts(ks);
394 	}
395 
396 	/* if something stopped the rx process, probably due to wanting
397 	 * to change the rx settings, then do something about restarting
398 	 * it. */
399 	if (status & IRQ_RXPSI) {
400 		struct ks8851_rxctrl *rxc = &ks->rxctrl;
401 
402 		/* update the multicast hash table */
403 		ks8851_wrreg16(ks, KS_MAHTR0, rxc->mchash[0]);
404 		ks8851_wrreg16(ks, KS_MAHTR1, rxc->mchash[1]);
405 		ks8851_wrreg16(ks, KS_MAHTR2, rxc->mchash[2]);
406 		ks8851_wrreg16(ks, KS_MAHTR3, rxc->mchash[3]);
407 
408 		ks8851_wrreg16(ks, KS_RXCR2, rxc->rxcr2);
409 		ks8851_wrreg16(ks, KS_RXCR1, rxc->rxcr1);
410 	}
411 
412 	ks8851_unlock(ks, &flags);
413 
414 	if (status & IRQ_LCI)
415 		mii_check_link(&ks->mii);
416 
417 	if (status & IRQ_TXI)
418 		netif_wake_queue(ks->netdev);
419 
420 	return IRQ_HANDLED;
421 }
422 
423 /**
424  * ks8851_flush_tx_work - flush outstanding TX work
425  * @ks: The device state
426  */
427 static void ks8851_flush_tx_work(struct ks8851_net *ks)
428 {
429 	if (ks->flush_tx_work)
430 		ks->flush_tx_work(ks);
431 }
432 
433 /**
434  * ks8851_net_open - open network device
435  * @dev: The network device being opened.
436  *
437  * Called when the network device is marked active, such as a user executing
438  * 'ifconfig up' on the device.
439  */
440 static int ks8851_net_open(struct net_device *dev)
441 {
442 	struct ks8851_net *ks = netdev_priv(dev);
443 	unsigned long flags;
444 	int ret;
445 
446 	ret = request_threaded_irq(dev->irq, NULL, ks8851_irq,
447 				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
448 				   dev->name, ks);
449 	if (ret < 0) {
450 		netdev_err(dev, "failed to get irq\n");
451 		return ret;
452 	}
453 
454 	/* lock the card, even if we may not actually be doing anything
455 	 * else at the moment */
456 	ks8851_lock(ks, &flags);
457 
458 	netif_dbg(ks, ifup, ks->netdev, "opening\n");
459 
460 	/* bring chip out of any power saving mode it was in */
461 	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
462 
463 	/* issue a soft reset to the RX/TX QMU to put it into a known
464 	 * state. */
465 	ks8851_soft_reset(ks, GRR_QMU);
466 
467 	/* setup transmission parameters */
468 
469 	ks8851_wrreg16(ks, KS_TXCR, (TXCR_TXE | /* enable transmit process */
470 				     TXCR_TXPE | /* pad to min length */
471 				     TXCR_TXCRC | /* add CRC */
472 				     TXCR_TXFCE)); /* enable flow control */
473 
474 	/* auto-increment tx data, reset tx pointer */
475 	ks8851_wrreg16(ks, KS_TXFDPR, TXFDPR_TXFPAI);
476 
477 	/* setup receiver control */
478 
479 	ks8851_wrreg16(ks, KS_RXCR1, (RXCR1_RXPAFMA | /*  from mac filter */
480 				      RXCR1_RXFCE | /* enable flow control */
481 				      RXCR1_RXBE | /* broadcast enable */
482 				      RXCR1_RXUE | /* unicast enable */
483 				      RXCR1_RXE)); /* enable rx block */
484 
485 	/* transfer entire frames out in one go */
486 	ks8851_wrreg16(ks, KS_RXCR2, RXCR2_SRDBL_FRAME);
487 
488 	/* set receive counter timeouts */
489 	ks8851_wrreg16(ks, KS_RXDTTR, 1000); /* 1ms after first frame to IRQ */
490 	ks8851_wrreg16(ks, KS_RXDBCTR, 4096); /* >4Kbytes in buffer to IRQ */
491 	ks8851_wrreg16(ks, KS_RXFCTR, 10);  /* 10 frames to IRQ */
492 
493 	ks->rc_rxqcr = (RXQCR_RXFCTE |  /* IRQ on frame count exceeded */
494 			RXQCR_RXDBCTE | /* IRQ on byte count exceeded */
495 			RXQCR_RXDTTE);  /* IRQ on time exceeded */
496 
497 	ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr);
498 
499 	/* clear then enable interrupts */
500 	ks8851_wrreg16(ks, KS_ISR, ks->rc_ier);
501 	ks8851_wrreg16(ks, KS_IER, ks->rc_ier);
502 
503 	netif_start_queue(ks->netdev);
504 
505 	netif_dbg(ks, ifup, ks->netdev, "network device up\n");
506 
507 	ks8851_unlock(ks, &flags);
508 	mii_check_link(&ks->mii);
509 	return 0;
510 }
511 
512 /**
513  * ks8851_net_stop - close network device
514  * @dev: The device being closed.
515  *
516  * Called to close down a network device which has been active. Cancell any
517  * work, shutdown the RX and TX process and then place the chip into a low
518  * power state whilst it is not being used.
519  */
520 static int ks8851_net_stop(struct net_device *dev)
521 {
522 	struct ks8851_net *ks = netdev_priv(dev);
523 	unsigned long flags;
524 
525 	netif_info(ks, ifdown, dev, "shutting down\n");
526 
527 	netif_stop_queue(dev);
528 
529 	ks8851_lock(ks, &flags);
530 	/* turn off the IRQs and ack any outstanding */
531 	ks8851_wrreg16(ks, KS_IER, 0x0000);
532 	ks8851_wrreg16(ks, KS_ISR, 0xffff);
533 	ks8851_unlock(ks, &flags);
534 
535 	/* stop any outstanding work */
536 	ks8851_flush_tx_work(ks);
537 	flush_work(&ks->rxctrl_work);
538 
539 	ks8851_lock(ks, &flags);
540 	/* shutdown RX process */
541 	ks8851_wrreg16(ks, KS_RXCR1, 0x0000);
542 
543 	/* shutdown TX process */
544 	ks8851_wrreg16(ks, KS_TXCR, 0x0000);
545 
546 	/* set powermode to soft power down to save power */
547 	ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
548 	ks8851_unlock(ks, &flags);
549 
550 	/* ensure any queued tx buffers are dumped */
551 	while (!skb_queue_empty(&ks->txq)) {
552 		struct sk_buff *txb = skb_dequeue(&ks->txq);
553 
554 		netif_dbg(ks, ifdown, ks->netdev,
555 			  "%s: freeing txb %p\n", __func__, txb);
556 
557 		dev_kfree_skb(txb);
558 	}
559 
560 	free_irq(dev->irq, ks);
561 
562 	return 0;
563 }
564 
565 /**
566  * ks8851_start_xmit - transmit packet
567  * @skb: The buffer to transmit
568  * @dev: The device used to transmit the packet.
569  *
570  * Called by the network layer to transmit the @skb. Queue the packet for
571  * the device and schedule the necessary work to transmit the packet when
572  * it is free.
573  *
574  * We do this to firstly avoid sleeping with the network device locked,
575  * and secondly so we can round up more than one packet to transmit which
576  * means we can try and avoid generating too many transmit done interrupts.
577  */
578 static netdev_tx_t ks8851_start_xmit(struct sk_buff *skb,
579 				     struct net_device *dev)
580 {
581 	struct ks8851_net *ks = netdev_priv(dev);
582 
583 	return ks->start_xmit(skb, dev);
584 }
585 
586 /**
587  * ks8851_rxctrl_work - work handler to change rx mode
588  * @work: The work structure this belongs to.
589  *
590  * Lock the device and issue the necessary changes to the receive mode from
591  * the network device layer. This is done so that we can do this without
592  * having to sleep whilst holding the network device lock.
593  *
594  * Since the recommendation from Micrel is that the RXQ is shutdown whilst the
595  * receive parameters are programmed, we issue a write to disable the RXQ and
596  * then wait for the interrupt handler to be triggered once the RXQ shutdown is
597  * complete. The interrupt handler then writes the new values into the chip.
598  */
599 static void ks8851_rxctrl_work(struct work_struct *work)
600 {
601 	struct ks8851_net *ks = container_of(work, struct ks8851_net, rxctrl_work);
602 	unsigned long flags;
603 
604 	ks8851_lock(ks, &flags);
605 
606 	/* need to shutdown RXQ before modifying filter parameters */
607 	ks8851_wrreg16(ks, KS_RXCR1, 0x00);
608 
609 	ks8851_unlock(ks, &flags);
610 }
611 
612 static void ks8851_set_rx_mode(struct net_device *dev)
613 {
614 	struct ks8851_net *ks = netdev_priv(dev);
615 	struct ks8851_rxctrl rxctrl;
616 
617 	memset(&rxctrl, 0, sizeof(rxctrl));
618 
619 	if (dev->flags & IFF_PROMISC) {
620 		/* interface to receive everything */
621 
622 		rxctrl.rxcr1 = RXCR1_RXAE | RXCR1_RXINVF;
623 	} else if (dev->flags & IFF_ALLMULTI) {
624 		/* accept all multicast packets */
625 
626 		rxctrl.rxcr1 = (RXCR1_RXME | RXCR1_RXAE |
627 				RXCR1_RXPAFMA | RXCR1_RXMAFMA);
628 	} else if (dev->flags & IFF_MULTICAST && !netdev_mc_empty(dev)) {
629 		struct netdev_hw_addr *ha;
630 		u32 crc;
631 
632 		/* accept some multicast */
633 
634 		netdev_for_each_mc_addr(ha, dev) {
635 			crc = ether_crc(ETH_ALEN, ha->addr);
636 			crc >>= (32 - 6);  /* get top six bits */
637 
638 			rxctrl.mchash[crc >> 4] |= (1 << (crc & 0xf));
639 		}
640 
641 		rxctrl.rxcr1 = RXCR1_RXME | RXCR1_RXPAFMA;
642 	} else {
643 		/* just accept broadcast / unicast */
644 		rxctrl.rxcr1 = RXCR1_RXPAFMA;
645 	}
646 
647 	rxctrl.rxcr1 |= (RXCR1_RXUE | /* unicast enable */
648 			 RXCR1_RXBE | /* broadcast enable */
649 			 RXCR1_RXE | /* RX process enable */
650 			 RXCR1_RXFCE); /* enable flow control */
651 
652 	rxctrl.rxcr2 |= RXCR2_SRDBL_FRAME;
653 
654 	/* schedule work to do the actual set of the data if needed */
655 
656 	spin_lock(&ks->statelock);
657 
658 	if (memcmp(&rxctrl, &ks->rxctrl, sizeof(rxctrl)) != 0) {
659 		memcpy(&ks->rxctrl, &rxctrl, sizeof(ks->rxctrl));
660 		schedule_work(&ks->rxctrl_work);
661 	}
662 
663 	spin_unlock(&ks->statelock);
664 }
665 
666 static int ks8851_set_mac_address(struct net_device *dev, void *addr)
667 {
668 	struct sockaddr *sa = addr;
669 
670 	if (netif_running(dev))
671 		return -EBUSY;
672 
673 	if (!is_valid_ether_addr(sa->sa_data))
674 		return -EADDRNOTAVAIL;
675 
676 	memcpy(dev->dev_addr, sa->sa_data, ETH_ALEN);
677 	return ks8851_write_mac_addr(dev);
678 }
679 
680 static int ks8851_net_ioctl(struct net_device *dev, struct ifreq *req, int cmd)
681 {
682 	struct ks8851_net *ks = netdev_priv(dev);
683 
684 	if (!netif_running(dev))
685 		return -EINVAL;
686 
687 	return generic_mii_ioctl(&ks->mii, if_mii(req), cmd, NULL);
688 }
689 
690 static const struct net_device_ops ks8851_netdev_ops = {
691 	.ndo_open		= ks8851_net_open,
692 	.ndo_stop		= ks8851_net_stop,
693 	.ndo_do_ioctl		= ks8851_net_ioctl,
694 	.ndo_start_xmit		= ks8851_start_xmit,
695 	.ndo_set_mac_address	= ks8851_set_mac_address,
696 	.ndo_set_rx_mode	= ks8851_set_rx_mode,
697 	.ndo_validate_addr	= eth_validate_addr,
698 };
699 
700 /* ethtool support */
701 
702 static void ks8851_get_drvinfo(struct net_device *dev,
703 			       struct ethtool_drvinfo *di)
704 {
705 	strlcpy(di->driver, "KS8851", sizeof(di->driver));
706 	strlcpy(di->version, "1.00", sizeof(di->version));
707 	strlcpy(di->bus_info, dev_name(dev->dev.parent), sizeof(di->bus_info));
708 }
709 
710 static u32 ks8851_get_msglevel(struct net_device *dev)
711 {
712 	struct ks8851_net *ks = netdev_priv(dev);
713 	return ks->msg_enable;
714 }
715 
716 static void ks8851_set_msglevel(struct net_device *dev, u32 to)
717 {
718 	struct ks8851_net *ks = netdev_priv(dev);
719 	ks->msg_enable = to;
720 }
721 
722 static int ks8851_get_link_ksettings(struct net_device *dev,
723 				     struct ethtool_link_ksettings *cmd)
724 {
725 	struct ks8851_net *ks = netdev_priv(dev);
726 
727 	mii_ethtool_get_link_ksettings(&ks->mii, cmd);
728 
729 	return 0;
730 }
731 
732 static int ks8851_set_link_ksettings(struct net_device *dev,
733 				     const struct ethtool_link_ksettings *cmd)
734 {
735 	struct ks8851_net *ks = netdev_priv(dev);
736 	return mii_ethtool_set_link_ksettings(&ks->mii, cmd);
737 }
738 
739 static u32 ks8851_get_link(struct net_device *dev)
740 {
741 	struct ks8851_net *ks = netdev_priv(dev);
742 	return mii_link_ok(&ks->mii);
743 }
744 
745 static int ks8851_nway_reset(struct net_device *dev)
746 {
747 	struct ks8851_net *ks = netdev_priv(dev);
748 	return mii_nway_restart(&ks->mii);
749 }
750 
751 /* EEPROM support */
752 
753 static void ks8851_eeprom_regread(struct eeprom_93cx6 *ee)
754 {
755 	struct ks8851_net *ks = ee->data;
756 	unsigned val;
757 
758 	val = ks8851_rdreg16(ks, KS_EEPCR);
759 
760 	ee->reg_data_out = (val & EEPCR_EESB) ? 1 : 0;
761 	ee->reg_data_clock = (val & EEPCR_EESCK) ? 1 : 0;
762 	ee->reg_chip_select = (val & EEPCR_EECS) ? 1 : 0;
763 }
764 
765 static void ks8851_eeprom_regwrite(struct eeprom_93cx6 *ee)
766 {
767 	struct ks8851_net *ks = ee->data;
768 	unsigned val = EEPCR_EESA;	/* default - eeprom access on */
769 
770 	if (ee->drive_data)
771 		val |= EEPCR_EESRWA;
772 	if (ee->reg_data_in)
773 		val |= EEPCR_EEDO;
774 	if (ee->reg_data_clock)
775 		val |= EEPCR_EESCK;
776 	if (ee->reg_chip_select)
777 		val |= EEPCR_EECS;
778 
779 	ks8851_wrreg16(ks, KS_EEPCR, val);
780 }
781 
782 /**
783  * ks8851_eeprom_claim - claim device EEPROM and activate the interface
784  * @ks: The network device state.
785  *
786  * Check for the presence of an EEPROM, and then activate software access
787  * to the device.
788  */
789 static int ks8851_eeprom_claim(struct ks8851_net *ks)
790 {
791 	/* start with clock low, cs high */
792 	ks8851_wrreg16(ks, KS_EEPCR, EEPCR_EESA | EEPCR_EECS);
793 	return 0;
794 }
795 
796 /**
797  * ks8851_eeprom_release - release the EEPROM interface
798  * @ks: The device state
799  *
800  * Release the software access to the device EEPROM
801  */
802 static void ks8851_eeprom_release(struct ks8851_net *ks)
803 {
804 	unsigned val = ks8851_rdreg16(ks, KS_EEPCR);
805 
806 	ks8851_wrreg16(ks, KS_EEPCR, val & ~EEPCR_EESA);
807 }
808 
809 #define KS_EEPROM_MAGIC (0x00008851)
810 
811 static int ks8851_set_eeprom(struct net_device *dev,
812 			     struct ethtool_eeprom *ee, u8 *data)
813 {
814 	struct ks8851_net *ks = netdev_priv(dev);
815 	int offset = ee->offset;
816 	unsigned long flags;
817 	int len = ee->len;
818 	u16 tmp;
819 
820 	/* currently only support byte writing */
821 	if (len != 1)
822 		return -EINVAL;
823 
824 	if (ee->magic != KS_EEPROM_MAGIC)
825 		return -EINVAL;
826 
827 	if (!(ks->rc_ccr & CCR_EEPROM))
828 		return -ENOENT;
829 
830 	ks8851_lock(ks, &flags);
831 
832 	ks8851_eeprom_claim(ks);
833 
834 	eeprom_93cx6_wren(&ks->eeprom, true);
835 
836 	/* ethtool currently only supports writing bytes, which means
837 	 * we have to read/modify/write our 16bit EEPROMs */
838 
839 	eeprom_93cx6_read(&ks->eeprom, offset/2, &tmp);
840 
841 	if (offset & 1) {
842 		tmp &= 0xff;
843 		tmp |= *data << 8;
844 	} else {
845 		tmp &= 0xff00;
846 		tmp |= *data;
847 	}
848 
849 	eeprom_93cx6_write(&ks->eeprom, offset/2, tmp);
850 	eeprom_93cx6_wren(&ks->eeprom, false);
851 
852 	ks8851_eeprom_release(ks);
853 	ks8851_unlock(ks, &flags);
854 
855 	return 0;
856 }
857 
858 static int ks8851_get_eeprom(struct net_device *dev,
859 			     struct ethtool_eeprom *ee, u8 *data)
860 {
861 	struct ks8851_net *ks = netdev_priv(dev);
862 	int offset = ee->offset;
863 	unsigned long flags;
864 	int len = ee->len;
865 
866 	/* must be 2 byte aligned */
867 	if (len & 1 || offset & 1)
868 		return -EINVAL;
869 
870 	if (!(ks->rc_ccr & CCR_EEPROM))
871 		return -ENOENT;
872 
873 	ks8851_lock(ks, &flags);
874 
875 	ks8851_eeprom_claim(ks);
876 
877 	ee->magic = KS_EEPROM_MAGIC;
878 
879 	eeprom_93cx6_multiread(&ks->eeprom, offset/2, (__le16 *)data, len/2);
880 	ks8851_eeprom_release(ks);
881 	ks8851_unlock(ks, &flags);
882 
883 	return 0;
884 }
885 
886 static int ks8851_get_eeprom_len(struct net_device *dev)
887 {
888 	struct ks8851_net *ks = netdev_priv(dev);
889 
890 	/* currently, we assume it is an 93C46 attached, so return 128 */
891 	return ks->rc_ccr & CCR_EEPROM ? 128 : 0;
892 }
893 
894 static const struct ethtool_ops ks8851_ethtool_ops = {
895 	.get_drvinfo	= ks8851_get_drvinfo,
896 	.get_msglevel	= ks8851_get_msglevel,
897 	.set_msglevel	= ks8851_set_msglevel,
898 	.get_link	= ks8851_get_link,
899 	.nway_reset	= ks8851_nway_reset,
900 	.get_eeprom_len	= ks8851_get_eeprom_len,
901 	.get_eeprom	= ks8851_get_eeprom,
902 	.set_eeprom	= ks8851_set_eeprom,
903 	.get_link_ksettings = ks8851_get_link_ksettings,
904 	.set_link_ksettings = ks8851_set_link_ksettings,
905 };
906 
907 /* MII interface controls */
908 
909 /**
910  * ks8851_phy_reg - convert MII register into a KS8851 register
911  * @reg: MII register number.
912  *
913  * Return the KS8851 register number for the corresponding MII PHY register
914  * if possible. Return zero if the MII register has no direct mapping to the
915  * KS8851 register set.
916  */
917 static int ks8851_phy_reg(int reg)
918 {
919 	switch (reg) {
920 	case MII_BMCR:
921 		return KS_P1MBCR;
922 	case MII_BMSR:
923 		return KS_P1MBSR;
924 	case MII_PHYSID1:
925 		return KS_PHY1ILR;
926 	case MII_PHYSID2:
927 		return KS_PHY1IHR;
928 	case MII_ADVERTISE:
929 		return KS_P1ANAR;
930 	case MII_LPA:
931 		return KS_P1ANLPR;
932 	}
933 
934 	return -EOPNOTSUPP;
935 }
936 
937 static int ks8851_phy_read_common(struct net_device *dev, int phy_addr, int reg)
938 {
939 	struct ks8851_net *ks = netdev_priv(dev);
940 	unsigned long flags;
941 	int result;
942 	int ksreg;
943 
944 	ksreg = ks8851_phy_reg(reg);
945 	if (ksreg < 0)
946 		return ksreg;
947 
948 	ks8851_lock(ks, &flags);
949 	result = ks8851_rdreg16(ks, ksreg);
950 	ks8851_unlock(ks, &flags);
951 
952 	return result;
953 }
954 
955 /**
956  * ks8851_phy_read - MII interface PHY register read.
957  * @dev: The network device the PHY is on.
958  * @phy_addr: Address of PHY (ignored as we only have one)
959  * @reg: The register to read.
960  *
961  * This call reads data from the PHY register specified in @reg. Since the
962  * device does not support all the MII registers, the non-existent values
963  * are always returned as zero.
964  *
965  * We return zero for unsupported registers as the MII code does not check
966  * the value returned for any error status, and simply returns it to the
967  * caller. The mii-tool that the driver was tested with takes any -ve error
968  * as real PHY capabilities, thus displaying incorrect data to the user.
969  */
970 static int ks8851_phy_read(struct net_device *dev, int phy_addr, int reg)
971 {
972 	int ret;
973 
974 	ret = ks8851_phy_read_common(dev, phy_addr, reg);
975 	if (ret < 0)
976 		return 0x0;	/* no error return allowed, so use zero */
977 
978 	return ret;
979 }
980 
981 static void ks8851_phy_write(struct net_device *dev,
982 			     int phy, int reg, int value)
983 {
984 	struct ks8851_net *ks = netdev_priv(dev);
985 	unsigned long flags;
986 	int ksreg;
987 
988 	ksreg = ks8851_phy_reg(reg);
989 	if (ksreg >= 0) {
990 		ks8851_lock(ks, &flags);
991 		ks8851_wrreg16(ks, ksreg, value);
992 		ks8851_unlock(ks, &flags);
993 	}
994 }
995 
996 static int ks8851_mdio_read(struct mii_bus *bus, int phy_id, int reg)
997 {
998 	struct ks8851_net *ks = bus->priv;
999 
1000 	if (phy_id != 0)
1001 		return -EOPNOTSUPP;
1002 
1003 	/* KS8851 PHY ID registers are swapped in HW, swap them back. */
1004 	if (reg == MII_PHYSID1)
1005 		reg = MII_PHYSID2;
1006 	else if (reg == MII_PHYSID2)
1007 		reg = MII_PHYSID1;
1008 
1009 	return ks8851_phy_read_common(ks->netdev, phy_id, reg);
1010 }
1011 
1012 static int ks8851_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
1013 {
1014 	struct ks8851_net *ks = bus->priv;
1015 
1016 	ks8851_phy_write(ks->netdev, phy_id, reg, val);
1017 	return 0;
1018 }
1019 
1020 /**
1021  * ks8851_read_selftest - read the selftest memory info.
1022  * @ks: The device state
1023  *
1024  * Read and check the TX/RX memory selftest information.
1025  */
1026 static int ks8851_read_selftest(struct ks8851_net *ks)
1027 {
1028 	unsigned both_done = MBIR_TXMBF | MBIR_RXMBF;
1029 	int ret = 0;
1030 	unsigned rd;
1031 
1032 	rd = ks8851_rdreg16(ks, KS_MBIR);
1033 
1034 	if ((rd & both_done) != both_done) {
1035 		netdev_warn(ks->netdev, "Memory selftest not finished\n");
1036 		return 0;
1037 	}
1038 
1039 	if (rd & MBIR_TXMBFA) {
1040 		netdev_err(ks->netdev, "TX memory selftest fail\n");
1041 		ret |= 1;
1042 	}
1043 
1044 	if (rd & MBIR_RXMBFA) {
1045 		netdev_err(ks->netdev, "RX memory selftest fail\n");
1046 		ret |= 2;
1047 	}
1048 
1049 	return 0;
1050 }
1051 
1052 /* driver bus management functions */
1053 
1054 #ifdef CONFIG_PM_SLEEP
1055 
1056 int ks8851_suspend(struct device *dev)
1057 {
1058 	struct ks8851_net *ks = dev_get_drvdata(dev);
1059 	struct net_device *netdev = ks->netdev;
1060 
1061 	if (netif_running(netdev)) {
1062 		netif_device_detach(netdev);
1063 		ks8851_net_stop(netdev);
1064 	}
1065 
1066 	return 0;
1067 }
1068 
1069 int ks8851_resume(struct device *dev)
1070 {
1071 	struct ks8851_net *ks = dev_get_drvdata(dev);
1072 	struct net_device *netdev = ks->netdev;
1073 
1074 	if (netif_running(netdev)) {
1075 		ks8851_net_open(netdev);
1076 		netif_device_attach(netdev);
1077 	}
1078 
1079 	return 0;
1080 }
1081 #endif
1082 
1083 static int ks8851_register_mdiobus(struct ks8851_net *ks, struct device *dev)
1084 {
1085 	struct mii_bus *mii_bus;
1086 	int ret;
1087 
1088 	mii_bus = mdiobus_alloc();
1089 	if (!mii_bus)
1090 		return -ENOMEM;
1091 
1092 	mii_bus->name = "ks8851_eth_mii";
1093 	mii_bus->read = ks8851_mdio_read;
1094 	mii_bus->write = ks8851_mdio_write;
1095 	mii_bus->priv = ks;
1096 	mii_bus->parent = dev;
1097 	mii_bus->phy_mask = ~((u32)BIT(0));
1098 	snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
1099 
1100 	ret = mdiobus_register(mii_bus);
1101 	if (ret)
1102 		goto err_mdiobus_register;
1103 
1104 	ks->mii_bus = mii_bus;
1105 
1106 	return 0;
1107 
1108 err_mdiobus_register:
1109 	mdiobus_free(mii_bus);
1110 	return ret;
1111 }
1112 
1113 static void ks8851_unregister_mdiobus(struct ks8851_net *ks)
1114 {
1115 	mdiobus_unregister(ks->mii_bus);
1116 	mdiobus_free(ks->mii_bus);
1117 }
1118 
1119 int ks8851_probe_common(struct net_device *netdev, struct device *dev,
1120 			int msg_en)
1121 {
1122 	struct ks8851_net *ks = netdev_priv(netdev);
1123 	unsigned cider;
1124 	int gpio;
1125 	int ret;
1126 
1127 	ks->netdev = netdev;
1128 	ks->tx_space = 6144;
1129 
1130 	gpio = of_get_named_gpio_flags(dev->of_node, "reset-gpios", 0, NULL);
1131 	if (gpio == -EPROBE_DEFER)
1132 		return gpio;
1133 
1134 	ks->gpio = gpio;
1135 	if (gpio_is_valid(gpio)) {
1136 		ret = devm_gpio_request_one(dev, gpio,
1137 					    GPIOF_OUT_INIT_LOW, "ks8851_rst_n");
1138 		if (ret) {
1139 			dev_err(dev, "reset gpio request failed\n");
1140 			return ret;
1141 		}
1142 	}
1143 
1144 	ks->vdd_io = devm_regulator_get(dev, "vdd-io");
1145 	if (IS_ERR(ks->vdd_io)) {
1146 		ret = PTR_ERR(ks->vdd_io);
1147 		goto err_reg_io;
1148 	}
1149 
1150 	ret = regulator_enable(ks->vdd_io);
1151 	if (ret) {
1152 		dev_err(dev, "regulator vdd_io enable fail: %d\n", ret);
1153 		goto err_reg_io;
1154 	}
1155 
1156 	ks->vdd_reg = devm_regulator_get(dev, "vdd");
1157 	if (IS_ERR(ks->vdd_reg)) {
1158 		ret = PTR_ERR(ks->vdd_reg);
1159 		goto err_reg;
1160 	}
1161 
1162 	ret = regulator_enable(ks->vdd_reg);
1163 	if (ret) {
1164 		dev_err(dev, "regulator vdd enable fail: %d\n", ret);
1165 		goto err_reg;
1166 	}
1167 
1168 	if (gpio_is_valid(gpio)) {
1169 		usleep_range(10000, 11000);
1170 		gpio_set_value(gpio, 1);
1171 	}
1172 
1173 	spin_lock_init(&ks->statelock);
1174 
1175 	INIT_WORK(&ks->rxctrl_work, ks8851_rxctrl_work);
1176 
1177 	SET_NETDEV_DEV(netdev, dev);
1178 
1179 	/* setup EEPROM state */
1180 	ks->eeprom.data = ks;
1181 	ks->eeprom.width = PCI_EEPROM_WIDTH_93C46;
1182 	ks->eeprom.register_read = ks8851_eeprom_regread;
1183 	ks->eeprom.register_write = ks8851_eeprom_regwrite;
1184 
1185 	/* setup mii state */
1186 	ks->mii.dev		= netdev;
1187 	ks->mii.phy_id		= 1;
1188 	ks->mii.phy_id_mask	= 1;
1189 	ks->mii.reg_num_mask	= 0xf;
1190 	ks->mii.mdio_read	= ks8851_phy_read;
1191 	ks->mii.mdio_write	= ks8851_phy_write;
1192 
1193 	dev_info(dev, "message enable is %d\n", msg_en);
1194 
1195 	ret = ks8851_register_mdiobus(ks, dev);
1196 	if (ret)
1197 		goto err_mdio;
1198 
1199 	/* set the default message enable */
1200 	ks->msg_enable = netif_msg_init(msg_en, NETIF_MSG_DRV |
1201 						NETIF_MSG_PROBE |
1202 						NETIF_MSG_LINK);
1203 
1204 	skb_queue_head_init(&ks->txq);
1205 
1206 	netdev->ethtool_ops = &ks8851_ethtool_ops;
1207 
1208 	dev_set_drvdata(dev, ks);
1209 
1210 	netif_carrier_off(ks->netdev);
1211 	netdev->if_port = IF_PORT_100BASET;
1212 	netdev->netdev_ops = &ks8851_netdev_ops;
1213 
1214 	/* issue a global soft reset to reset the device. */
1215 	ks8851_soft_reset(ks, GRR_GSR);
1216 
1217 	/* simple check for a valid chip being connected to the bus */
1218 	cider = ks8851_rdreg16(ks, KS_CIDER);
1219 	if ((cider & ~CIDER_REV_MASK) != CIDER_ID) {
1220 		dev_err(dev, "failed to read device ID\n");
1221 		ret = -ENODEV;
1222 		goto err_id;
1223 	}
1224 
1225 	/* cache the contents of the CCR register for EEPROM, etc. */
1226 	ks->rc_ccr = ks8851_rdreg16(ks, KS_CCR);
1227 
1228 	ks8851_read_selftest(ks);
1229 	ks8851_init_mac(ks, dev->of_node);
1230 
1231 	ret = register_netdev(netdev);
1232 	if (ret) {
1233 		dev_err(dev, "failed to register network device\n");
1234 		goto err_id;
1235 	}
1236 
1237 	netdev_info(netdev, "revision %d, MAC %pM, IRQ %d, %s EEPROM\n",
1238 		    CIDER_REV_GET(cider), netdev->dev_addr, netdev->irq,
1239 		    ks->rc_ccr & CCR_EEPROM ? "has" : "no");
1240 
1241 	return 0;
1242 
1243 err_id:
1244 	ks8851_unregister_mdiobus(ks);
1245 err_mdio:
1246 	if (gpio_is_valid(gpio))
1247 		gpio_set_value(gpio, 0);
1248 	regulator_disable(ks->vdd_reg);
1249 err_reg:
1250 	regulator_disable(ks->vdd_io);
1251 err_reg_io:
1252 	return ret;
1253 }
1254 
1255 int ks8851_remove_common(struct device *dev)
1256 {
1257 	struct ks8851_net *priv = dev_get_drvdata(dev);
1258 
1259 	ks8851_unregister_mdiobus(priv);
1260 
1261 	if (netif_msg_drv(priv))
1262 		dev_info(dev, "remove\n");
1263 
1264 	unregister_netdev(priv->netdev);
1265 	if (gpio_is_valid(priv->gpio))
1266 		gpio_set_value(priv->gpio, 0);
1267 	regulator_disable(priv->vdd_reg);
1268 	regulator_disable(priv->vdd_io);
1269 
1270 	return 0;
1271 }
1272