1 /* MOXA ART Ethernet (RTL8201CP) driver.
2  *
3  * Copyright (C) 2013 Jonas Jensen
4  *
5  * Jonas Jensen <jonas.jensen@gmail.com>
6  *
7  * Based on code from
8  * Moxa Technology Co., Ltd. <www.moxa.com>
9  *
10  * This file is licensed under the terms of the GNU General Public
11  * License version 2.  This program is licensed "as is" without any
12  * warranty of any kind, whether express or implied.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/netdevice.h>
18 #include <linux/etherdevice.h>
19 #include <linux/skbuff.h>
20 #include <linux/dma-mapping.h>
21 #include <linux/ethtool.h>
22 #include <linux/platform_device.h>
23 #include <linux/interrupt.h>
24 #include <linux/irq.h>
25 #include <linux/of_address.h>
26 #include <linux/of_irq.h>
27 #include <linux/crc32.h>
28 #include <linux/crc32c.h>
29 #include <linux/dma-mapping.h>
30 
31 #include "moxart_ether.h"
32 
33 static inline void moxart_emac_write(struct net_device *ndev,
34 				     unsigned int reg, unsigned long value)
35 {
36 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
37 
38 	writel(value, priv->base + reg);
39 }
40 
41 static void moxart_update_mac_address(struct net_device *ndev)
42 {
43 	moxart_emac_write(ndev, REG_MAC_MS_ADDRESS,
44 			  ((ndev->dev_addr[0] << 8) | (ndev->dev_addr[1])));
45 	moxart_emac_write(ndev, REG_MAC_MS_ADDRESS + 4,
46 			  ((ndev->dev_addr[2] << 24) |
47 			   (ndev->dev_addr[3] << 16) |
48 			   (ndev->dev_addr[4] << 8) |
49 			   (ndev->dev_addr[5])));
50 }
51 
52 static int moxart_set_mac_address(struct net_device *ndev, void *addr)
53 {
54 	struct sockaddr *address = addr;
55 
56 	if (!is_valid_ether_addr(address->sa_data))
57 		return -EADDRNOTAVAIL;
58 
59 	memcpy(ndev->dev_addr, address->sa_data, ndev->addr_len);
60 	moxart_update_mac_address(ndev);
61 
62 	return 0;
63 }
64 
65 static void moxart_mac_free_memory(struct net_device *ndev)
66 {
67 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
68 	int i;
69 
70 	for (i = 0; i < RX_DESC_NUM; i++)
71 		dma_unmap_single(&ndev->dev, priv->rx_mapping[i],
72 				 priv->rx_buf_size, DMA_FROM_DEVICE);
73 
74 	if (priv->tx_desc_base)
75 		dma_free_coherent(NULL, TX_REG_DESC_SIZE * TX_DESC_NUM,
76 				  priv->tx_desc_base, priv->tx_base);
77 
78 	if (priv->rx_desc_base)
79 		dma_free_coherent(NULL, RX_REG_DESC_SIZE * RX_DESC_NUM,
80 				  priv->rx_desc_base, priv->rx_base);
81 
82 	kfree(priv->tx_buf_base);
83 	kfree(priv->rx_buf_base);
84 }
85 
86 static void moxart_mac_reset(struct net_device *ndev)
87 {
88 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
89 
90 	writel(SW_RST, priv->base + REG_MAC_CTRL);
91 	while (readl(priv->base + REG_MAC_CTRL) & SW_RST)
92 		mdelay(10);
93 
94 	writel(0, priv->base + REG_INTERRUPT_MASK);
95 
96 	priv->reg_maccr = RX_BROADPKT | FULLDUP | CRC_APD | RX_FTL;
97 }
98 
99 static void moxart_mac_enable(struct net_device *ndev)
100 {
101 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
102 
103 	writel(0x00001010, priv->base + REG_INT_TIMER_CTRL);
104 	writel(0x00000001, priv->base + REG_APOLL_TIMER_CTRL);
105 	writel(0x00000390, priv->base + REG_DMA_BLEN_CTRL);
106 
107 	priv->reg_imr |= (RPKT_FINISH_M | XPKT_FINISH_M);
108 	writel(priv->reg_imr, priv->base + REG_INTERRUPT_MASK);
109 
110 	priv->reg_maccr |= (RCV_EN | XMT_EN | RDMA_EN | XDMA_EN);
111 	writel(priv->reg_maccr, priv->base + REG_MAC_CTRL);
112 }
113 
114 static void moxart_mac_setup_desc_ring(struct net_device *ndev)
115 {
116 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
117 	void __iomem *desc;
118 	int i;
119 
120 	for (i = 0; i < TX_DESC_NUM; i++) {
121 		desc = priv->tx_desc_base + i * TX_REG_DESC_SIZE;
122 		memset(desc, 0, TX_REG_DESC_SIZE);
123 
124 		priv->tx_buf[i] = priv->tx_buf_base + priv->tx_buf_size * i;
125 	}
126 	writel(TX_DESC1_END, desc + TX_REG_OFFSET_DESC1);
127 
128 	priv->tx_head = 0;
129 	priv->tx_tail = 0;
130 
131 	for (i = 0; i < RX_DESC_NUM; i++) {
132 		desc = priv->rx_desc_base + i * RX_REG_DESC_SIZE;
133 		memset(desc, 0, RX_REG_DESC_SIZE);
134 		writel(RX_DESC0_DMA_OWN, desc + RX_REG_OFFSET_DESC0);
135 		writel(RX_BUF_SIZE & RX_DESC1_BUF_SIZE_MASK,
136 		       desc + RX_REG_OFFSET_DESC1);
137 
138 		priv->rx_buf[i] = priv->rx_buf_base + priv->rx_buf_size * i;
139 		priv->rx_mapping[i] = dma_map_single(&ndev->dev,
140 						     priv->rx_buf[i],
141 						     priv->rx_buf_size,
142 						     DMA_FROM_DEVICE);
143 		if (dma_mapping_error(&ndev->dev, priv->rx_mapping[i]))
144 			netdev_err(ndev, "DMA mapping error\n");
145 
146 		writel(priv->rx_mapping[i],
147 		       desc + RX_REG_OFFSET_DESC2 + RX_DESC2_ADDRESS_PHYS);
148 		writel(priv->rx_buf[i],
149 		       desc + RX_REG_OFFSET_DESC2 + RX_DESC2_ADDRESS_VIRT);
150 	}
151 	writel(RX_DESC1_END, desc + RX_REG_OFFSET_DESC1);
152 
153 	priv->rx_head = 0;
154 
155 	/* reset the MAC controler TX/RX desciptor base address */
156 	writel(priv->tx_base, priv->base + REG_TXR_BASE_ADDRESS);
157 	writel(priv->rx_base, priv->base + REG_RXR_BASE_ADDRESS);
158 }
159 
160 static int moxart_mac_open(struct net_device *ndev)
161 {
162 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
163 
164 	if (!is_valid_ether_addr(ndev->dev_addr))
165 		return -EADDRNOTAVAIL;
166 
167 	napi_enable(&priv->napi);
168 
169 	moxart_mac_reset(ndev);
170 	moxart_update_mac_address(ndev);
171 	moxart_mac_setup_desc_ring(ndev);
172 	moxart_mac_enable(ndev);
173 	netif_start_queue(ndev);
174 
175 	netdev_dbg(ndev, "%s: IMR=0x%x, MACCR=0x%x\n",
176 		   __func__, readl(priv->base + REG_INTERRUPT_MASK),
177 		   readl(priv->base + REG_MAC_CTRL));
178 
179 	return 0;
180 }
181 
182 static int moxart_mac_stop(struct net_device *ndev)
183 {
184 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
185 
186 	napi_disable(&priv->napi);
187 
188 	netif_stop_queue(ndev);
189 
190 	/* disable all interrupts */
191 	writel(0, priv->base + REG_INTERRUPT_MASK);
192 
193 	/* disable all functions */
194 	writel(0, priv->base + REG_MAC_CTRL);
195 
196 	return 0;
197 }
198 
199 static int moxart_rx_poll(struct napi_struct *napi, int budget)
200 {
201 	struct moxart_mac_priv_t *priv = container_of(napi,
202 						      struct moxart_mac_priv_t,
203 						      napi);
204 	struct net_device *ndev = priv->ndev;
205 	struct sk_buff *skb;
206 	void __iomem *desc;
207 	unsigned int desc0, len;
208 	int rx_head = priv->rx_head;
209 	int rx = 0;
210 
211 	while (1) {
212 		desc = priv->rx_desc_base + (RX_REG_DESC_SIZE * rx_head);
213 		desc0 = readl(desc + RX_REG_OFFSET_DESC0);
214 
215 		if (desc0 & RX_DESC0_DMA_OWN)
216 			break;
217 
218 		if (desc0 & (RX_DESC0_ERR | RX_DESC0_CRC_ERR | RX_DESC0_FTL |
219 			     RX_DESC0_RUNT | RX_DESC0_ODD_NB)) {
220 			net_dbg_ratelimited("packet error\n");
221 			priv->stats.rx_dropped++;
222 			priv->stats.rx_errors++;
223 			continue;
224 		}
225 
226 		len = desc0 & RX_DESC0_FRAME_LEN_MASK;
227 
228 		if (len > RX_BUF_SIZE)
229 			len = RX_BUF_SIZE;
230 
231 		skb = build_skb(priv->rx_buf[rx_head], priv->rx_buf_size);
232 		if (unlikely(!skb)) {
233 			net_dbg_ratelimited("build_skb failed\n");
234 			priv->stats.rx_dropped++;
235 			priv->stats.rx_errors++;
236 		}
237 
238 		skb_put(skb, len);
239 		skb->protocol = eth_type_trans(skb, ndev);
240 		napi_gro_receive(&priv->napi, skb);
241 		rx++;
242 
243 		ndev->last_rx = jiffies;
244 		priv->stats.rx_packets++;
245 		priv->stats.rx_bytes += len;
246 		if (desc0 & RX_DESC0_MULTICAST)
247 			priv->stats.multicast++;
248 
249 		writel(RX_DESC0_DMA_OWN, desc + RX_REG_OFFSET_DESC0);
250 
251 		rx_head = RX_NEXT(rx_head);
252 		priv->rx_head = rx_head;
253 
254 		if (rx >= budget)
255 			break;
256 	}
257 
258 	if (rx < budget) {
259 		napi_gro_flush(napi, false);
260 		__napi_complete(napi);
261 	}
262 
263 	priv->reg_imr |= RPKT_FINISH_M;
264 	writel(priv->reg_imr, priv->base + REG_INTERRUPT_MASK);
265 
266 	return rx;
267 }
268 
269 static void moxart_tx_finished(struct net_device *ndev)
270 {
271 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
272 	unsigned tx_head = priv->tx_head;
273 	unsigned tx_tail = priv->tx_tail;
274 
275 	while (tx_tail != tx_head) {
276 		dma_unmap_single(&ndev->dev, priv->tx_mapping[tx_tail],
277 				 priv->tx_len[tx_tail], DMA_TO_DEVICE);
278 
279 		priv->stats.tx_packets++;
280 		priv->stats.tx_bytes += priv->tx_skb[tx_tail]->len;
281 
282 		dev_kfree_skb_irq(priv->tx_skb[tx_tail]);
283 		priv->tx_skb[tx_tail] = NULL;
284 
285 		tx_tail = TX_NEXT(tx_tail);
286 	}
287 	priv->tx_tail = tx_tail;
288 }
289 
290 static irqreturn_t moxart_mac_interrupt(int irq, void *dev_id)
291 {
292 	struct net_device *ndev = (struct net_device *) dev_id;
293 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
294 	unsigned int ists = readl(priv->base + REG_INTERRUPT_STATUS);
295 
296 	if (ists & XPKT_OK_INT_STS)
297 		moxart_tx_finished(ndev);
298 
299 	if (ists & RPKT_FINISH) {
300 		if (napi_schedule_prep(&priv->napi)) {
301 			priv->reg_imr &= ~RPKT_FINISH_M;
302 			writel(priv->reg_imr, priv->base + REG_INTERRUPT_MASK);
303 			__napi_schedule(&priv->napi);
304 		}
305 	}
306 
307 	return IRQ_HANDLED;
308 }
309 
310 static int moxart_mac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
311 {
312 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
313 	void __iomem *desc;
314 	unsigned int len;
315 	unsigned int tx_head = priv->tx_head;
316 	u32 txdes1;
317 	int ret = NETDEV_TX_BUSY;
318 
319 	desc = priv->tx_desc_base + (TX_REG_DESC_SIZE * tx_head);
320 
321 	spin_lock_irq(&priv->txlock);
322 	if (readl(desc + TX_REG_OFFSET_DESC0) & TX_DESC0_DMA_OWN) {
323 		net_dbg_ratelimited("no TX space for packet\n");
324 		priv->stats.tx_dropped++;
325 		goto out_unlock;
326 	}
327 
328 	len = skb->len > TX_BUF_SIZE ? TX_BUF_SIZE : skb->len;
329 
330 	priv->tx_mapping[tx_head] = dma_map_single(&ndev->dev, skb->data,
331 						   len, DMA_TO_DEVICE);
332 	if (dma_mapping_error(&ndev->dev, priv->tx_mapping[tx_head])) {
333 		netdev_err(ndev, "DMA mapping error\n");
334 		goto out_unlock;
335 	}
336 
337 	priv->tx_len[tx_head] = len;
338 	priv->tx_skb[tx_head] = skb;
339 
340 	writel(priv->tx_mapping[tx_head],
341 	       desc + TX_REG_OFFSET_DESC2 + TX_DESC2_ADDRESS_PHYS);
342 	writel(skb->data,
343 	       desc + TX_REG_OFFSET_DESC2 + TX_DESC2_ADDRESS_VIRT);
344 
345 	if (skb->len < ETH_ZLEN) {
346 		memset(&skb->data[skb->len],
347 		       0, ETH_ZLEN - skb->len);
348 		len = ETH_ZLEN;
349 	}
350 
351 	txdes1 = readl(desc + TX_REG_OFFSET_DESC1);
352 	txdes1 |= TX_DESC1_LTS | TX_DESC1_FTS;
353 	txdes1 &= ~(TX_DESC1_FIFO_COMPLETE | TX_DESC1_INTR_COMPLETE);
354 	txdes1 |= (len & TX_DESC1_BUF_SIZE_MASK);
355 	writel(txdes1, desc + TX_REG_OFFSET_DESC1);
356 	writel(TX_DESC0_DMA_OWN, desc + TX_REG_OFFSET_DESC0);
357 
358 	/* start to send packet */
359 	writel(0xffffffff, priv->base + REG_TX_POLL_DEMAND);
360 
361 	priv->tx_head = TX_NEXT(tx_head);
362 
363 	ndev->trans_start = jiffies;
364 	ret = NETDEV_TX_OK;
365 out_unlock:
366 	spin_unlock_irq(&priv->txlock);
367 
368 	return ret;
369 }
370 
371 static struct net_device_stats *moxart_mac_get_stats(struct net_device *ndev)
372 {
373 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
374 
375 	return &priv->stats;
376 }
377 
378 static void moxart_mac_setmulticast(struct net_device *ndev)
379 {
380 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
381 	struct netdev_hw_addr *ha;
382 	int crc_val;
383 
384 	netdev_for_each_mc_addr(ha, ndev) {
385 		crc_val = crc32_le(~0, ha->addr, ETH_ALEN);
386 		crc_val = (crc_val >> 26) & 0x3f;
387 		if (crc_val >= 32) {
388 			writel(readl(priv->base + REG_MCAST_HASH_TABLE1) |
389 			       (1UL << (crc_val - 32)),
390 			       priv->base + REG_MCAST_HASH_TABLE1);
391 		} else {
392 			writel(readl(priv->base + REG_MCAST_HASH_TABLE0) |
393 			       (1UL << crc_val),
394 			       priv->base + REG_MCAST_HASH_TABLE0);
395 		}
396 	}
397 }
398 
399 static void moxart_mac_set_rx_mode(struct net_device *ndev)
400 {
401 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
402 
403 	spin_lock_irq(&priv->txlock);
404 
405 	(ndev->flags & IFF_PROMISC) ? (priv->reg_maccr |= RCV_ALL) :
406 				      (priv->reg_maccr &= ~RCV_ALL);
407 
408 	(ndev->flags & IFF_ALLMULTI) ? (priv->reg_maccr |= RX_MULTIPKT) :
409 				       (priv->reg_maccr &= ~RX_MULTIPKT);
410 
411 	if ((ndev->flags & IFF_MULTICAST) && netdev_mc_count(ndev)) {
412 		priv->reg_maccr |= HT_MULTI_EN;
413 		moxart_mac_setmulticast(ndev);
414 	} else {
415 		priv->reg_maccr &= ~HT_MULTI_EN;
416 	}
417 
418 	writel(priv->reg_maccr, priv->base + REG_MAC_CTRL);
419 
420 	spin_unlock_irq(&priv->txlock);
421 }
422 
423 static struct net_device_ops moxart_netdev_ops = {
424 	.ndo_open		= moxart_mac_open,
425 	.ndo_stop		= moxart_mac_stop,
426 	.ndo_start_xmit		= moxart_mac_start_xmit,
427 	.ndo_get_stats		= moxart_mac_get_stats,
428 	.ndo_set_rx_mode	= moxart_mac_set_rx_mode,
429 	.ndo_set_mac_address	= moxart_set_mac_address,
430 	.ndo_validate_addr	= eth_validate_addr,
431 	.ndo_change_mtu		= eth_change_mtu,
432 };
433 
434 static int moxart_mac_probe(struct platform_device *pdev)
435 {
436 	struct device *p_dev = &pdev->dev;
437 	struct device_node *node = p_dev->of_node;
438 	struct net_device *ndev;
439 	struct moxart_mac_priv_t *priv;
440 	struct resource *res;
441 	unsigned int irq;
442 	int ret;
443 
444 	ndev = alloc_etherdev(sizeof(struct moxart_mac_priv_t));
445 	if (!ndev)
446 		return -ENOMEM;
447 
448 	irq = irq_of_parse_and_map(node, 0);
449 	if (irq <= 0) {
450 		netdev_err(ndev, "irq_of_parse_and_map failed\n");
451 		return -EINVAL;
452 	}
453 
454 	priv = netdev_priv(ndev);
455 	priv->ndev = ndev;
456 
457 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
458 	ndev->base_addr = res->start;
459 	priv->base = devm_ioremap_resource(p_dev, res);
460 	ret = IS_ERR(priv->base);
461 	if (ret) {
462 		dev_err(p_dev, "devm_ioremap_resource failed\n");
463 		goto init_fail;
464 	}
465 
466 	spin_lock_init(&priv->txlock);
467 
468 	priv->tx_buf_size = TX_BUF_SIZE;
469 	priv->rx_buf_size = RX_BUF_SIZE +
470 			    SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
471 
472 	priv->tx_desc_base = dma_alloc_coherent(NULL, TX_REG_DESC_SIZE *
473 						TX_DESC_NUM, &priv->tx_base,
474 						GFP_DMA | GFP_KERNEL);
475 	if (priv->tx_desc_base == NULL)
476 		goto init_fail;
477 
478 	priv->rx_desc_base = dma_alloc_coherent(NULL, RX_REG_DESC_SIZE *
479 						RX_DESC_NUM, &priv->rx_base,
480 						GFP_DMA | GFP_KERNEL);
481 	if (priv->rx_desc_base == NULL)
482 		goto init_fail;
483 
484 	priv->tx_buf_base = kmalloc(priv->tx_buf_size * TX_DESC_NUM,
485 				    GFP_ATOMIC);
486 	if (!priv->tx_buf_base)
487 		goto init_fail;
488 
489 	priv->rx_buf_base = kmalloc(priv->rx_buf_size * RX_DESC_NUM,
490 				    GFP_ATOMIC);
491 	if (!priv->rx_buf_base)
492 		goto init_fail;
493 
494 	platform_set_drvdata(pdev, ndev);
495 
496 	ret = devm_request_irq(p_dev, irq, moxart_mac_interrupt, 0,
497 			       pdev->name, ndev);
498 	if (ret) {
499 		netdev_err(ndev, "devm_request_irq failed\n");
500 		goto init_fail;
501 	}
502 
503 	ether_setup(ndev);
504 	ndev->netdev_ops = &moxart_netdev_ops;
505 	netif_napi_add(ndev, &priv->napi, moxart_rx_poll, RX_DESC_NUM);
506 	ndev->priv_flags |= IFF_UNICAST_FLT;
507 	ndev->irq = irq;
508 
509 	SET_NETDEV_DEV(ndev, &pdev->dev);
510 
511 	ret = register_netdev(ndev);
512 	if (ret) {
513 		free_netdev(ndev);
514 		goto init_fail;
515 	}
516 
517 	netdev_dbg(ndev, "%s: IRQ=%d address=%pM\n",
518 		   __func__, ndev->irq, ndev->dev_addr);
519 
520 	return 0;
521 
522 init_fail:
523 	netdev_err(ndev, "init failed\n");
524 	moxart_mac_free_memory(ndev);
525 
526 	return ret;
527 }
528 
529 static int moxart_remove(struct platform_device *pdev)
530 {
531 	struct net_device *ndev = platform_get_drvdata(pdev);
532 
533 	unregister_netdev(ndev);
534 	free_irq(ndev->irq, ndev);
535 	moxart_mac_free_memory(ndev);
536 	free_netdev(ndev);
537 
538 	return 0;
539 }
540 
541 static const struct of_device_id moxart_mac_match[] = {
542 	{ .compatible = "moxa,moxart-mac" },
543 	{ }
544 };
545 
546 struct __initdata platform_driver moxart_mac_driver = {
547 	.probe	= moxart_mac_probe,
548 	.remove	= moxart_remove,
549 	.driver	= {
550 		.name		= "moxart-ethernet",
551 		.owner		= THIS_MODULE,
552 		.of_match_table	= moxart_mac_match,
553 	},
554 };
555 module_platform_driver(moxart_mac_driver);
556 
557 MODULE_DESCRIPTION("MOXART RTL8201CP Ethernet driver");
558 MODULE_LICENSE("GPL v2");
559 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
560