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/netdevice.h>
17#include <linux/etherdevice.h>
18#include <linux/skbuff.h>
19#include <linux/dma-mapping.h>
20#include <linux/ethtool.h>
21#include <linux/platform_device.h>
22#include <linux/interrupt.h>
23#include <linux/irq.h>
24#include <linux/of_address.h>
25#include <linux/of_irq.h>
26#include <linux/crc32.h>
27#include <linux/crc32c.h>
28#include <linux/circ_buf.h>
29
30#include "moxart_ether.h"
31
32static inline void moxart_desc_write(u32 data, u32 *desc)
33{
34	*desc = cpu_to_le32(data);
35}
36
37static inline u32 moxart_desc_read(u32 *desc)
38{
39	return le32_to_cpu(*desc);
40}
41
42static inline void moxart_emac_write(struct net_device *ndev,
43				     unsigned int reg, unsigned long value)
44{
45	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
46
47	writel(value, priv->base + reg);
48}
49
50static void moxart_update_mac_address(struct net_device *ndev)
51{
52	moxart_emac_write(ndev, REG_MAC_MS_ADDRESS,
53			  ((ndev->dev_addr[0] << 8) | (ndev->dev_addr[1])));
54	moxart_emac_write(ndev, REG_MAC_MS_ADDRESS + 4,
55			  ((ndev->dev_addr[2] << 24) |
56			   (ndev->dev_addr[3] << 16) |
57			   (ndev->dev_addr[4] << 8) |
58			   (ndev->dev_addr[5])));
59}
60
61static int moxart_set_mac_address(struct net_device *ndev, void *addr)
62{
63	struct sockaddr *address = addr;
64
65	if (!is_valid_ether_addr(address->sa_data))
66		return -EADDRNOTAVAIL;
67
68	memcpy(ndev->dev_addr, address->sa_data, ndev->addr_len);
69	moxart_update_mac_address(ndev);
70
71	return 0;
72}
73
74static void moxart_mac_free_memory(struct net_device *ndev)
75{
76	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
77
78	if (priv->tx_desc_base)
79		dma_free_coherent(&priv->pdev->dev,
80				  TX_REG_DESC_SIZE * TX_DESC_NUM,
81				  priv->tx_desc_base, priv->tx_base);
82
83	if (priv->rx_desc_base)
84		dma_free_coherent(&priv->pdev->dev,
85				  RX_REG_DESC_SIZE * RX_DESC_NUM,
86				  priv->rx_desc_base, priv->rx_base);
87
88	kfree(priv->tx_buf_base);
89	kfree(priv->rx_buf_base);
90}
91
92static void moxart_mac_reset(struct net_device *ndev)
93{
94	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
95
96	writel(SW_RST, priv->base + REG_MAC_CTRL);
97	while (readl(priv->base + REG_MAC_CTRL) & SW_RST)
98		mdelay(10);
99
100	writel(0, priv->base + REG_INTERRUPT_MASK);
101
102	priv->reg_maccr = RX_BROADPKT | FULLDUP | CRC_APD | RX_FTL;
103}
104
105static void moxart_mac_enable(struct net_device *ndev)
106{
107	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
108
109	writel(0x00001010, priv->base + REG_INT_TIMER_CTRL);
110	writel(0x00000001, priv->base + REG_APOLL_TIMER_CTRL);
111	writel(0x00000390, priv->base + REG_DMA_BLEN_CTRL);
112
113	priv->reg_imr |= (RPKT_FINISH_M | XPKT_FINISH_M);
114	writel(priv->reg_imr, priv->base + REG_INTERRUPT_MASK);
115
116	priv->reg_maccr |= (RCV_EN | XMT_EN | RDMA_EN | XDMA_EN);
117	writel(priv->reg_maccr, priv->base + REG_MAC_CTRL);
118}
119
120static void moxart_mac_setup_desc_ring(struct net_device *ndev)
121{
122	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
123	void *desc;
124	int i;
125
126	for (i = 0; i < TX_DESC_NUM; i++) {
127		desc = priv->tx_desc_base + i * TX_REG_DESC_SIZE;
128		memset(desc, 0, TX_REG_DESC_SIZE);
129
130		priv->tx_buf[i] = priv->tx_buf_base + priv->tx_buf_size * i;
131	}
132	moxart_desc_write(TX_DESC1_END, desc + TX_REG_OFFSET_DESC1);
133
134	priv->tx_head = 0;
135	priv->tx_tail = 0;
136
137	for (i = 0; i < RX_DESC_NUM; i++) {
138		desc = priv->rx_desc_base + i * RX_REG_DESC_SIZE;
139		memset(desc, 0, RX_REG_DESC_SIZE);
140		moxart_desc_write(RX_DESC0_DMA_OWN, desc + RX_REG_OFFSET_DESC0);
141		moxart_desc_write(RX_BUF_SIZE & RX_DESC1_BUF_SIZE_MASK,
142		       desc + RX_REG_OFFSET_DESC1);
143
144		priv->rx_buf[i] = priv->rx_buf_base + priv->rx_buf_size * i;
145		priv->rx_mapping[i] = dma_map_single(&priv->pdev->dev,
146						     priv->rx_buf[i],
147						     priv->rx_buf_size,
148						     DMA_FROM_DEVICE);
149		if (dma_mapping_error(&priv->pdev->dev, priv->rx_mapping[i]))
150			netdev_err(ndev, "DMA mapping error\n");
151
152		moxart_desc_write(priv->rx_mapping[i],
153		       desc + RX_REG_OFFSET_DESC2 + RX_DESC2_ADDRESS_PHYS);
154		moxart_desc_write((uintptr_t)priv->rx_buf[i],
155		       desc + RX_REG_OFFSET_DESC2 + RX_DESC2_ADDRESS_VIRT);
156	}
157	moxart_desc_write(RX_DESC1_END, desc + RX_REG_OFFSET_DESC1);
158
159	priv->rx_head = 0;
160
161	/* reset the MAC controller TX/RX descriptor base address */
162	writel(priv->tx_base, priv->base + REG_TXR_BASE_ADDRESS);
163	writel(priv->rx_base, priv->base + REG_RXR_BASE_ADDRESS);
164}
165
166static int moxart_mac_open(struct net_device *ndev)
167{
168	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
169
170	if (!is_valid_ether_addr(ndev->dev_addr))
171		return -EADDRNOTAVAIL;
172
173	napi_enable(&priv->napi);
174
175	moxart_mac_reset(ndev);
176	moxart_update_mac_address(ndev);
177	moxart_mac_setup_desc_ring(ndev);
178	moxart_mac_enable(ndev);
179	netif_start_queue(ndev);
180
181	netdev_dbg(ndev, "%s: IMR=0x%x, MACCR=0x%x\n",
182		   __func__, readl(priv->base + REG_INTERRUPT_MASK),
183		   readl(priv->base + REG_MAC_CTRL));
184
185	return 0;
186}
187
188static int moxart_mac_stop(struct net_device *ndev)
189{
190	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
191	int i;
192
193	napi_disable(&priv->napi);
194
195	netif_stop_queue(ndev);
196
197	/* disable all interrupts */
198	writel(0, priv->base + REG_INTERRUPT_MASK);
199
200	/* disable all functions */
201	writel(0, priv->base + REG_MAC_CTRL);
202
203	/* unmap areas mapped in moxart_mac_setup_desc_ring() */
204	for (i = 0; i < RX_DESC_NUM; i++)
205		dma_unmap_single(&priv->pdev->dev, priv->rx_mapping[i],
206				 priv->rx_buf_size, DMA_FROM_DEVICE);
207
208	return 0;
209}
210
211static int moxart_rx_poll(struct napi_struct *napi, int budget)
212{
213	struct moxart_mac_priv_t *priv = container_of(napi,
214						      struct moxart_mac_priv_t,
215						      napi);
216	struct net_device *ndev = priv->ndev;
217	struct sk_buff *skb;
218	void *desc;
219	unsigned int desc0, len;
220	int rx_head = priv->rx_head;
221	int rx = 0;
222
223	while (rx < budget) {
224		desc = priv->rx_desc_base + (RX_REG_DESC_SIZE * rx_head);
225		desc0 = moxart_desc_read(desc + RX_REG_OFFSET_DESC0);
226		rmb(); /* ensure desc0 is up to date */
227
228		if (desc0 & RX_DESC0_DMA_OWN)
229			break;
230
231		if (desc0 & (RX_DESC0_ERR | RX_DESC0_CRC_ERR | RX_DESC0_FTL |
232			     RX_DESC0_RUNT | RX_DESC0_ODD_NB)) {
233			net_dbg_ratelimited("packet error\n");
234			ndev->stats.rx_dropped++;
235			ndev->stats.rx_errors++;
236			goto rx_next;
237		}
238
239		len = desc0 & RX_DESC0_FRAME_LEN_MASK;
240
241		if (len > RX_BUF_SIZE)
242			len = RX_BUF_SIZE;
243
244		dma_sync_single_for_cpu(&priv->pdev->dev,
245					priv->rx_mapping[rx_head],
246					priv->rx_buf_size, DMA_FROM_DEVICE);
247		skb = netdev_alloc_skb_ip_align(ndev, len);
248
249		if (unlikely(!skb)) {
250			net_dbg_ratelimited("netdev_alloc_skb_ip_align failed\n");
251			ndev->stats.rx_dropped++;
252			ndev->stats.rx_errors++;
253			goto rx_next;
254		}
255
256		memcpy(skb->data, priv->rx_buf[rx_head], len);
257		skb_put(skb, len);
258		skb->protocol = eth_type_trans(skb, ndev);
259		napi_gro_receive(&priv->napi, skb);
260		rx++;
261
262		ndev->stats.rx_packets++;
263		ndev->stats.rx_bytes += len;
264		if (desc0 & RX_DESC0_MULTICAST)
265			ndev->stats.multicast++;
266
267rx_next:
268		wmb(); /* prevent setting ownership back too early */
269		moxart_desc_write(RX_DESC0_DMA_OWN, desc + RX_REG_OFFSET_DESC0);
270
271		rx_head = RX_NEXT(rx_head);
272		priv->rx_head = rx_head;
273	}
274
275	if (rx < budget)
276		napi_complete_done(napi, rx);
277
278	priv->reg_imr |= RPKT_FINISH_M;
279	writel(priv->reg_imr, priv->base + REG_INTERRUPT_MASK);
280
281	return rx;
282}
283
284static int moxart_tx_queue_space(struct net_device *ndev)
285{
286	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
287
288	return CIRC_SPACE(priv->tx_head, priv->tx_tail, TX_DESC_NUM);
289}
290
291static void moxart_tx_finished(struct net_device *ndev)
292{
293	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
294	unsigned int tx_head = priv->tx_head;
295	unsigned int tx_tail = priv->tx_tail;
296
297	while (tx_tail != tx_head) {
298		dma_unmap_single(&priv->pdev->dev, priv->tx_mapping[tx_tail],
299				 priv->tx_len[tx_tail], DMA_TO_DEVICE);
300
301		ndev->stats.tx_packets++;
302		ndev->stats.tx_bytes += priv->tx_skb[tx_tail]->len;
303
304		dev_consume_skb_irq(priv->tx_skb[tx_tail]);
305		priv->tx_skb[tx_tail] = NULL;
306
307		tx_tail = TX_NEXT(tx_tail);
308	}
309	priv->tx_tail = tx_tail;
310	if (netif_queue_stopped(ndev) &&
311	    moxart_tx_queue_space(ndev) >= TX_WAKE_THRESHOLD)
312		netif_wake_queue(ndev);
313}
314
315static irqreturn_t moxart_mac_interrupt(int irq, void *dev_id)
316{
317	struct net_device *ndev = (struct net_device *)dev_id;
318	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
319	unsigned int ists = readl(priv->base + REG_INTERRUPT_STATUS);
320
321	if (ists & XPKT_OK_INT_STS)
322		moxart_tx_finished(ndev);
323
324	if (ists & RPKT_FINISH) {
325		if (napi_schedule_prep(&priv->napi)) {
326			priv->reg_imr &= ~RPKT_FINISH_M;
327			writel(priv->reg_imr, priv->base + REG_INTERRUPT_MASK);
328			__napi_schedule(&priv->napi);
329		}
330	}
331
332	return IRQ_HANDLED;
333}
334
335static netdev_tx_t moxart_mac_start_xmit(struct sk_buff *skb,
336					 struct net_device *ndev)
337{
338	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
339	void *desc;
340	unsigned int len;
341	unsigned int tx_head;
342	u32 txdes1;
343	netdev_tx_t ret = NETDEV_TX_BUSY;
344
345	spin_lock_irq(&priv->txlock);
346
347	tx_head = priv->tx_head;
348	desc = priv->tx_desc_base + (TX_REG_DESC_SIZE * tx_head);
349
350	if (moxart_tx_queue_space(ndev) == 1)
351		netif_stop_queue(ndev);
352
353	if (moxart_desc_read(desc + TX_REG_OFFSET_DESC0) & TX_DESC0_DMA_OWN) {
354		net_dbg_ratelimited("no TX space for packet\n");
355		ndev->stats.tx_dropped++;
356		goto out_unlock;
357	}
358	rmb(); /* ensure data is only read that had TX_DESC0_DMA_OWN cleared */
359
360	len = skb->len > TX_BUF_SIZE ? TX_BUF_SIZE : skb->len;
361
362	priv->tx_mapping[tx_head] = dma_map_single(&priv->pdev->dev, skb->data,
363						   len, DMA_TO_DEVICE);
364	if (dma_mapping_error(&priv->pdev->dev, priv->tx_mapping[tx_head])) {
365		netdev_err(ndev, "DMA mapping error\n");
366		goto out_unlock;
367	}
368
369	priv->tx_len[tx_head] = len;
370	priv->tx_skb[tx_head] = skb;
371
372	moxart_desc_write(priv->tx_mapping[tx_head],
373	       desc + TX_REG_OFFSET_DESC2 + TX_DESC2_ADDRESS_PHYS);
374	moxart_desc_write((uintptr_t)skb->data,
375	       desc + TX_REG_OFFSET_DESC2 + TX_DESC2_ADDRESS_VIRT);
376
377	if (skb->len < ETH_ZLEN) {
378		memset(&skb->data[skb->len],
379		       0, ETH_ZLEN - skb->len);
380		len = ETH_ZLEN;
381	}
382
383	dma_sync_single_for_device(&priv->pdev->dev, priv->tx_mapping[tx_head],
384				   priv->tx_buf_size, DMA_TO_DEVICE);
385
386	txdes1 = TX_DESC1_LTS | TX_DESC1_FTS | (len & TX_DESC1_BUF_SIZE_MASK);
387	if (tx_head == TX_DESC_NUM_MASK)
388		txdes1 |= TX_DESC1_END;
389	moxart_desc_write(txdes1, desc + TX_REG_OFFSET_DESC1);
390	wmb(); /* flush descriptor before transferring ownership */
391	moxart_desc_write(TX_DESC0_DMA_OWN, desc + TX_REG_OFFSET_DESC0);
392
393	/* start to send packet */
394	writel(0xffffffff, priv->base + REG_TX_POLL_DEMAND);
395
396	priv->tx_head = TX_NEXT(tx_head);
397
398	netif_trans_update(ndev);
399	ret = NETDEV_TX_OK;
400out_unlock:
401	spin_unlock_irq(&priv->txlock);
402
403	return ret;
404}
405
406static void moxart_mac_setmulticast(struct net_device *ndev)
407{
408	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
409	struct netdev_hw_addr *ha;
410	int crc_val;
411
412	netdev_for_each_mc_addr(ha, ndev) {
413		crc_val = crc32_le(~0, ha->addr, ETH_ALEN);
414		crc_val = (crc_val >> 26) & 0x3f;
415		if (crc_val >= 32) {
416			writel(readl(priv->base + REG_MCAST_HASH_TABLE1) |
417			       (1UL << (crc_val - 32)),
418			       priv->base + REG_MCAST_HASH_TABLE1);
419		} else {
420			writel(readl(priv->base + REG_MCAST_HASH_TABLE0) |
421			       (1UL << crc_val),
422			       priv->base + REG_MCAST_HASH_TABLE0);
423		}
424	}
425}
426
427static void moxart_mac_set_rx_mode(struct net_device *ndev)
428{
429	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
430
431	spin_lock_irq(&priv->txlock);
432
433	(ndev->flags & IFF_PROMISC) ? (priv->reg_maccr |= RCV_ALL) :
434				      (priv->reg_maccr &= ~RCV_ALL);
435
436	(ndev->flags & IFF_ALLMULTI) ? (priv->reg_maccr |= RX_MULTIPKT) :
437				       (priv->reg_maccr &= ~RX_MULTIPKT);
438
439	if ((ndev->flags & IFF_MULTICAST) && netdev_mc_count(ndev)) {
440		priv->reg_maccr |= HT_MULTI_EN;
441		moxart_mac_setmulticast(ndev);
442	} else {
443		priv->reg_maccr &= ~HT_MULTI_EN;
444	}
445
446	writel(priv->reg_maccr, priv->base + REG_MAC_CTRL);
447
448	spin_unlock_irq(&priv->txlock);
449}
450
451static const struct net_device_ops moxart_netdev_ops = {
452	.ndo_open		= moxart_mac_open,
453	.ndo_stop		= moxart_mac_stop,
454	.ndo_start_xmit		= moxart_mac_start_xmit,
455	.ndo_set_rx_mode	= moxart_mac_set_rx_mode,
456	.ndo_set_mac_address	= moxart_set_mac_address,
457	.ndo_validate_addr	= eth_validate_addr,
458};
459
460static int moxart_mac_probe(struct platform_device *pdev)
461{
462	struct device *p_dev = &pdev->dev;
463	struct device_node *node = p_dev->of_node;
464	struct net_device *ndev;
465	struct moxart_mac_priv_t *priv;
466	struct resource *res;
467	unsigned int irq;
468	int ret;
469
470	ndev = alloc_etherdev(sizeof(struct moxart_mac_priv_t));
471	if (!ndev)
472		return -ENOMEM;
473
474	irq = irq_of_parse_and_map(node, 0);
475	if (irq <= 0) {
476		netdev_err(ndev, "irq_of_parse_and_map failed\n");
477		ret = -EINVAL;
478		goto irq_map_fail;
479	}
480
481	priv = netdev_priv(ndev);
482	priv->ndev = ndev;
483	priv->pdev = pdev;
484
485	priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
486	if (IS_ERR(priv->base)) {
487		dev_err(p_dev, "devm_ioremap_resource failed\n");
488		ret = PTR_ERR(priv->base);
489		goto init_fail;
490	}
491	ndev->base_addr = res->start;
492
493	spin_lock_init(&priv->txlock);
494
495	priv->tx_buf_size = TX_BUF_SIZE;
496	priv->rx_buf_size = RX_BUF_SIZE;
497
498	priv->tx_desc_base = dma_alloc_coherent(p_dev, TX_REG_DESC_SIZE *
499						TX_DESC_NUM, &priv->tx_base,
500						GFP_DMA | GFP_KERNEL);
501	if (!priv->tx_desc_base) {
502		ret = -ENOMEM;
503		goto init_fail;
504	}
505
506	priv->rx_desc_base = dma_alloc_coherent(p_dev, RX_REG_DESC_SIZE *
507						RX_DESC_NUM, &priv->rx_base,
508						GFP_DMA | GFP_KERNEL);
509	if (!priv->rx_desc_base) {
510		ret = -ENOMEM;
511		goto init_fail;
512	}
513
514	priv->tx_buf_base = kmalloc_array(priv->tx_buf_size, TX_DESC_NUM,
515					  GFP_ATOMIC);
516	if (!priv->tx_buf_base) {
517		ret = -ENOMEM;
518		goto init_fail;
519	}
520
521	priv->rx_buf_base = kmalloc_array(priv->rx_buf_size, RX_DESC_NUM,
522					  GFP_ATOMIC);
523	if (!priv->rx_buf_base) {
524		ret = -ENOMEM;
525		goto init_fail;
526	}
527
528	platform_set_drvdata(pdev, ndev);
529
530	ret = devm_request_irq(p_dev, irq, moxart_mac_interrupt, 0,
531			       pdev->name, ndev);
532	if (ret) {
533		netdev_err(ndev, "devm_request_irq failed\n");
534		goto init_fail;
535	}
536
537	ndev->netdev_ops = &moxart_netdev_ops;
538	netif_napi_add(ndev, &priv->napi, moxart_rx_poll, RX_DESC_NUM);
539	ndev->priv_flags |= IFF_UNICAST_FLT;
540	ndev->irq = irq;
541
542	SET_NETDEV_DEV(ndev, &pdev->dev);
543
544	ret = register_netdev(ndev);
545	if (ret)
546		goto init_fail;
547
548	netdev_dbg(ndev, "%s: IRQ=%d address=%pM\n",
549		   __func__, ndev->irq, ndev->dev_addr);
550
551	return 0;
552
553init_fail:
554	netdev_err(ndev, "init failed\n");
555	moxart_mac_free_memory(ndev);
556irq_map_fail:
557	free_netdev(ndev);
558	return ret;
559}
560
561static int moxart_remove(struct platform_device *pdev)
562{
563	struct net_device *ndev = platform_get_drvdata(pdev);
564
565	unregister_netdev(ndev);
566	devm_free_irq(&pdev->dev, ndev->irq, ndev);
567	moxart_mac_free_memory(ndev);
568	free_netdev(ndev);
569
570	return 0;
571}
572
573static const struct of_device_id moxart_mac_match[] = {
574	{ .compatible = "moxa,moxart-mac" },
575	{ }
576};
577MODULE_DEVICE_TABLE(of, moxart_mac_match);
578
579static struct platform_driver moxart_mac_driver = {
580	.probe	= moxart_mac_probe,
581	.remove	= moxart_remove,
582	.driver	= {
583		.name		= "moxart-ethernet",
584		.of_match_table	= moxart_mac_match,
585	},
586};
587module_platform_driver(moxart_mac_driver);
588
589MODULE_DESCRIPTION("MOXART RTL8201CP Ethernet driver");
590MODULE_LICENSE("GPL v2");
591MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
592