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