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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Lantiq / Intel PMAC driver for XRX200 SoCs
4 *
5 * Copyright (C) 2010 Lantiq Deutschland
6 * Copyright (C) 2012 John Crispin <john@phrozen.org>
7 * Copyright (C) 2017 - 2018 Hauke Mehrtens <hauke@hauke-m.de>
8 */
9
10#include <linux/etherdevice.h>
11#include <linux/module.h>
12#include <linux/platform_device.h>
13#include <linux/interrupt.h>
14#include <linux/clk.h>
15#include <linux/delay.h>
16
17#include <linux/of_net.h>
18#include <linux/of_platform.h>
19
20#include <xway_dma.h>
21
22/* DMA */
23#define XRX200_DMA_DATA_LEN 0x600
24#define XRX200_DMA_RX 0
25#define XRX200_DMA_TX 1
26
27/* cpu port mac */
28#define PMAC_RX_IPG 0x0024
29#define PMAC_RX_IPG_MASK 0xf
30
31#define PMAC_HD_CTL 0x0000
32/* Add Ethernet header to packets from DMA to PMAC */
33#define PMAC_HD_CTL_ADD BIT(0)
34/* Add VLAN tag to Packets from DMA to PMAC */
35#define PMAC_HD_CTL_TAG BIT(1)
36/* Add CRC to packets from DMA to PMAC */
37#define PMAC_HD_CTL_AC BIT(2)
38/* Add status header to packets from PMAC to DMA */
39#define PMAC_HD_CTL_AS BIT(3)
40/* Remove CRC from packets from PMAC to DMA */
41#define PMAC_HD_CTL_RC BIT(4)
42/* Remove Layer-2 header from packets from PMAC to DMA */
43#define PMAC_HD_CTL_RL2 BIT(5)
44/* Status header is present from DMA to PMAC */
45#define PMAC_HD_CTL_RXSH BIT(6)
46/* Add special tag from PMAC to switch */
47#define PMAC_HD_CTL_AST BIT(7)
48/* Remove specail Tag from PMAC to DMA */
49#define PMAC_HD_CTL_RST BIT(8)
50/* Check CRC from DMA to PMAC */
51#define PMAC_HD_CTL_CCRC BIT(9)
52/* Enable reaction to Pause frames in the PMAC */
53#define PMAC_HD_CTL_FC BIT(10)
54
55struct xrx200_chan {
56 int tx_free;
57
58 struct napi_struct napi;
59 struct ltq_dma_channel dma;
60 struct sk_buff *skb[LTQ_DESC_NUM];
61
62 struct xrx200_priv *priv;
63};
64
65struct xrx200_priv {
66 struct clk *clk;
67
68 struct xrx200_chan chan_tx;
69 struct xrx200_chan chan_rx;
70
71 struct net_device *net_dev;
72 struct device *dev;
73
74 __iomem void *pmac_reg;
75};
76
77static u32 xrx200_pmac_r32(struct xrx200_priv *priv, u32 offset)
78{
79 return __raw_readl(priv->pmac_reg + offset);
80}
81
82static void xrx200_pmac_w32(struct xrx200_priv *priv, u32 val, u32 offset)
83{
84 __raw_writel(val, priv->pmac_reg + offset);
85}
86
87static void xrx200_pmac_mask(struct xrx200_priv *priv, u32 clear, u32 set,
88 u32 offset)
89{
90 u32 val = xrx200_pmac_r32(priv, offset);
91
92 val &= ~(clear);
93 val |= set;
94 xrx200_pmac_w32(priv, val, offset);
95}
96
97/* drop all the packets from the DMA ring */
98static void xrx200_flush_dma(struct xrx200_chan *ch)
99{
100 int i;
101
102 for (i = 0; i < LTQ_DESC_NUM; i++) {
103 struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
104
105 if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) != LTQ_DMA_C)
106 break;
107
108 desc->ctl = LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
109 XRX200_DMA_DATA_LEN;
110 ch->dma.desc++;
111 ch->dma.desc %= LTQ_DESC_NUM;
112 }
113}
114
115static int xrx200_open(struct net_device *net_dev)
116{
117 struct xrx200_priv *priv = netdev_priv(net_dev);
118
119 napi_enable(&priv->chan_tx.napi);
120 ltq_dma_open(&priv->chan_tx.dma);
121 ltq_dma_enable_irq(&priv->chan_tx.dma);
122
123 napi_enable(&priv->chan_rx.napi);
124 ltq_dma_open(&priv->chan_rx.dma);
125 /* The boot loader does not always deactivate the receiving of frames
126 * on the ports and then some packets queue up in the PPE buffers.
127 * They already passed the PMAC so they do not have the tags
128 * configured here. Read the these packets here and drop them.
129 * The HW should have written them into memory after 10us
130 */
131 usleep_range(20, 40);
132 xrx200_flush_dma(&priv->chan_rx);
133 ltq_dma_enable_irq(&priv->chan_rx.dma);
134
135 netif_wake_queue(net_dev);
136
137 return 0;
138}
139
140static int xrx200_close(struct net_device *net_dev)
141{
142 struct xrx200_priv *priv = netdev_priv(net_dev);
143
144 netif_stop_queue(net_dev);
145
146 napi_disable(&priv->chan_rx.napi);
147 ltq_dma_close(&priv->chan_rx.dma);
148
149 napi_disable(&priv->chan_tx.napi);
150 ltq_dma_close(&priv->chan_tx.dma);
151
152 return 0;
153}
154
155static int xrx200_alloc_skb(struct xrx200_chan *ch)
156{
157 int ret = 0;
158
159 ch->skb[ch->dma.desc] = netdev_alloc_skb_ip_align(ch->priv->net_dev,
160 XRX200_DMA_DATA_LEN);
161 if (!ch->skb[ch->dma.desc]) {
162 ret = -ENOMEM;
163 goto skip;
164 }
165
166 ch->dma.desc_base[ch->dma.desc].addr = dma_map_single(ch->priv->dev,
167 ch->skb[ch->dma.desc]->data, XRX200_DMA_DATA_LEN,
168 DMA_FROM_DEVICE);
169 if (unlikely(dma_mapping_error(ch->priv->dev,
170 ch->dma.desc_base[ch->dma.desc].addr))) {
171 dev_kfree_skb_any(ch->skb[ch->dma.desc]);
172 ret = -ENOMEM;
173 goto skip;
174 }
175
176skip:
177 ch->dma.desc_base[ch->dma.desc].ctl =
178 LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
179 XRX200_DMA_DATA_LEN;
180
181 return ret;
182}
183
184static int xrx200_hw_receive(struct xrx200_chan *ch)
185{
186 struct xrx200_priv *priv = ch->priv;
187 struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
188 struct sk_buff *skb = ch->skb[ch->dma.desc];
189 int len = (desc->ctl & LTQ_DMA_SIZE_MASK);
190 struct net_device *net_dev = priv->net_dev;
191 int ret;
192
193 ret = xrx200_alloc_skb(ch);
194
195 ch->dma.desc++;
196 ch->dma.desc %= LTQ_DESC_NUM;
197
198 if (ret) {
199 netdev_err(net_dev, "failed to allocate new rx buffer\n");
200 return ret;
201 }
202
203 skb_put(skb, len);
204 skb->protocol = eth_type_trans(skb, net_dev);
205 netif_receive_skb(skb);
206 net_dev->stats.rx_packets++;
207 net_dev->stats.rx_bytes += len - ETH_FCS_LEN;
208
209 return 0;
210}
211
212static int xrx200_poll_rx(struct napi_struct *napi, int budget)
213{
214 struct xrx200_chan *ch = container_of(napi,
215 struct xrx200_chan, napi);
216 int rx = 0;
217 int ret;
218
219 while (rx < budget) {
220 struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
221
222 if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
223 ret = xrx200_hw_receive(ch);
224 if (ret)
225 return ret;
226 rx++;
227 } else {
228 break;
229 }
230 }
231
232 if (rx < budget) {
233 if (napi_complete_done(&ch->napi, rx))
234 ltq_dma_enable_irq(&ch->dma);
235 }
236
237 return rx;
238}
239
240static int xrx200_tx_housekeeping(struct napi_struct *napi, int budget)
241{
242 struct xrx200_chan *ch = container_of(napi,
243 struct xrx200_chan, napi);
244 struct net_device *net_dev = ch->priv->net_dev;
245 int pkts = 0;
246 int bytes = 0;
247
248 netif_tx_lock(net_dev);
249 while (pkts < budget) {
250 struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->tx_free];
251
252 if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
253 struct sk_buff *skb = ch->skb[ch->tx_free];
254
255 pkts++;
256 bytes += skb->len;
257 ch->skb[ch->tx_free] = NULL;
258 consume_skb(skb);
259 memset(&ch->dma.desc_base[ch->tx_free], 0,
260 sizeof(struct ltq_dma_desc));
261 ch->tx_free++;
262 ch->tx_free %= LTQ_DESC_NUM;
263 } else {
264 break;
265 }
266 }
267
268 net_dev->stats.tx_packets += pkts;
269 net_dev->stats.tx_bytes += bytes;
270 netdev_completed_queue(ch->priv->net_dev, pkts, bytes);
271
272 netif_tx_unlock(net_dev);
273 if (netif_queue_stopped(net_dev))
274 netif_wake_queue(net_dev);
275
276 if (pkts < budget) {
277 if (napi_complete_done(&ch->napi, pkts))
278 ltq_dma_enable_irq(&ch->dma);
279 }
280
281 return pkts;
282}
283
284static netdev_tx_t xrx200_start_xmit(struct sk_buff *skb,
285 struct net_device *net_dev)
286{
287 struct xrx200_priv *priv = netdev_priv(net_dev);
288 struct xrx200_chan *ch = &priv->chan_tx;
289 struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
290 u32 byte_offset;
291 dma_addr_t mapping;
292 int len;
293
294 skb->dev = net_dev;
295 if (skb_put_padto(skb, ETH_ZLEN)) {
296 net_dev->stats.tx_dropped++;
297 return NETDEV_TX_OK;
298 }
299
300 len = skb->len;
301
302 if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) || ch->skb[ch->dma.desc]) {
303 netdev_err(net_dev, "tx ring full\n");
304 netif_stop_queue(net_dev);
305 return NETDEV_TX_BUSY;
306 }
307
308 ch->skb[ch->dma.desc] = skb;
309
310 mapping = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);
311 if (unlikely(dma_mapping_error(priv->dev, mapping)))
312 goto err_drop;
313
314 /* dma needs to start on a 16 byte aligned address */
315 byte_offset = mapping % 16;
316
317 desc->addr = mapping - byte_offset;
318 /* Make sure the address is written before we give it to HW */
319 wmb();
320 desc->ctl = LTQ_DMA_OWN | LTQ_DMA_SOP | LTQ_DMA_EOP |
321 LTQ_DMA_TX_OFFSET(byte_offset) | (len & LTQ_DMA_SIZE_MASK);
322 ch->dma.desc++;
323 ch->dma.desc %= LTQ_DESC_NUM;
324 if (ch->dma.desc == ch->tx_free)
325 netif_stop_queue(net_dev);
326
327 netdev_sent_queue(net_dev, len);
328
329 return NETDEV_TX_OK;
330
331err_drop:
332 dev_kfree_skb(skb);
333 net_dev->stats.tx_dropped++;
334 net_dev->stats.tx_errors++;
335 return NETDEV_TX_OK;
336}
337
338static const struct net_device_ops xrx200_netdev_ops = {
339 .ndo_open = xrx200_open,
340 .ndo_stop = xrx200_close,
341 .ndo_start_xmit = xrx200_start_xmit,
342 .ndo_set_mac_address = eth_mac_addr,
343 .ndo_validate_addr = eth_validate_addr,
344};
345
346static irqreturn_t xrx200_dma_irq(int irq, void *ptr)
347{
348 struct xrx200_chan *ch = ptr;
349
350 if (napi_schedule_prep(&ch->napi)) {
351 __napi_schedule(&ch->napi);
352 ltq_dma_disable_irq(&ch->dma);
353 }
354
355 ltq_dma_ack_irq(&ch->dma);
356
357 return IRQ_HANDLED;
358}
359
360static int xrx200_dma_init(struct xrx200_priv *priv)
361{
362 struct xrx200_chan *ch_rx = &priv->chan_rx;
363 struct xrx200_chan *ch_tx = &priv->chan_tx;
364 int ret = 0;
365 int i;
366
367 ltq_dma_init_port(DMA_PORT_ETOP);
368
369 ch_rx->dma.nr = XRX200_DMA_RX;
370 ch_rx->dma.dev = priv->dev;
371 ch_rx->priv = priv;
372
373 ltq_dma_alloc_rx(&ch_rx->dma);
374 for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
375 ch_rx->dma.desc++) {
376 ret = xrx200_alloc_skb(ch_rx);
377 if (ret)
378 goto rx_free;
379 }
380 ch_rx->dma.desc = 0;
381 ret = devm_request_irq(priv->dev, ch_rx->dma.irq, xrx200_dma_irq, 0,
382 "xrx200_net_rx", &priv->chan_rx);
383 if (ret) {
384 dev_err(priv->dev, "failed to request RX irq %d\n",
385 ch_rx->dma.irq);
386 goto rx_ring_free;
387 }
388
389 ch_tx->dma.nr = XRX200_DMA_TX;
390 ch_tx->dma.dev = priv->dev;
391 ch_tx->priv = priv;
392
393 ltq_dma_alloc_tx(&ch_tx->dma);
394 ret = devm_request_irq(priv->dev, ch_tx->dma.irq, xrx200_dma_irq, 0,
395 "xrx200_net_tx", &priv->chan_tx);
396 if (ret) {
397 dev_err(priv->dev, "failed to request TX irq %d\n",
398 ch_tx->dma.irq);
399 goto tx_free;
400 }
401
402 return ret;
403
404tx_free:
405 ltq_dma_free(&ch_tx->dma);
406
407rx_ring_free:
408 /* free the allocated RX ring */
409 for (i = 0; i < LTQ_DESC_NUM; i++) {
410 if (priv->chan_rx.skb[i])
411 dev_kfree_skb_any(priv->chan_rx.skb[i]);
412 }
413
414rx_free:
415 ltq_dma_free(&ch_rx->dma);
416 return ret;
417}
418
419static void xrx200_hw_cleanup(struct xrx200_priv *priv)
420{
421 int i;
422
423 ltq_dma_free(&priv->chan_tx.dma);
424 ltq_dma_free(&priv->chan_rx.dma);
425
426 /* free the allocated RX ring */
427 for (i = 0; i < LTQ_DESC_NUM; i++)
428 dev_kfree_skb_any(priv->chan_rx.skb[i]);
429}
430
431static int xrx200_probe(struct platform_device *pdev)
432{
433 struct device *dev = &pdev->dev;
434 struct device_node *np = dev->of_node;
435 struct resource *res;
436 struct xrx200_priv *priv;
437 struct net_device *net_dev;
438 const u8 *mac;
439 int err;
440
441 /* alloc the network device */
442 net_dev = devm_alloc_etherdev(dev, sizeof(struct xrx200_priv));
443 if (!net_dev)
444 return -ENOMEM;
445
446 priv = netdev_priv(net_dev);
447 priv->net_dev = net_dev;
448 priv->dev = dev;
449
450 net_dev->netdev_ops = &xrx200_netdev_ops;
451 SET_NETDEV_DEV(net_dev, dev);
452 net_dev->min_mtu = ETH_ZLEN;
453 net_dev->max_mtu = XRX200_DMA_DATA_LEN;
454
455 /* load the memory ranges */
456 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
457 if (!res) {
458 dev_err(dev, "failed to get resources\n");
459 return -ENOENT;
460 }
461
462 priv->pmac_reg = devm_ioremap_resource(dev, res);
463 if (IS_ERR(priv->pmac_reg)) {
464 dev_err(dev, "failed to request and remap io ranges\n");
465 return PTR_ERR(priv->pmac_reg);
466 }
467
468 priv->chan_rx.dma.irq = platform_get_irq_byname(pdev, "rx");
469 if (priv->chan_rx.dma.irq < 0)
470 return -ENOENT;
471 priv->chan_tx.dma.irq = platform_get_irq_byname(pdev, "tx");
472 if (priv->chan_tx.dma.irq < 0)
473 return -ENOENT;
474
475 /* get the clock */
476 priv->clk = devm_clk_get(dev, NULL);
477 if (IS_ERR(priv->clk)) {
478 dev_err(dev, "failed to get clock\n");
479 return PTR_ERR(priv->clk);
480 }
481
482 mac = of_get_mac_address(np);
483 if (!IS_ERR(mac))
484 ether_addr_copy(net_dev->dev_addr, mac);
485 else
486 eth_hw_addr_random(net_dev);
487
488 /* bring up the dma engine and IP core */
489 err = xrx200_dma_init(priv);
490 if (err)
491 return err;
492
493 /* enable clock gate */
494 err = clk_prepare_enable(priv->clk);
495 if (err)
496 goto err_uninit_dma;
497
498 /* set IPG to 12 */
499 xrx200_pmac_mask(priv, PMAC_RX_IPG_MASK, 0xb, PMAC_RX_IPG);
500
501 /* enable status header, enable CRC */
502 xrx200_pmac_mask(priv, 0,
503 PMAC_HD_CTL_RST | PMAC_HD_CTL_AST | PMAC_HD_CTL_RXSH |
504 PMAC_HD_CTL_AS | PMAC_HD_CTL_AC | PMAC_HD_CTL_RC,
505 PMAC_HD_CTL);
506
507 /* setup NAPI */
508 netif_napi_add(net_dev, &priv->chan_rx.napi, xrx200_poll_rx, 32);
509 netif_tx_napi_add(net_dev, &priv->chan_tx.napi, xrx200_tx_housekeeping, 32);
510
511 platform_set_drvdata(pdev, priv);
512
513 err = register_netdev(net_dev);
514 if (err)
515 goto err_unprepare_clk;
516
517 return 0;
518
519err_unprepare_clk:
520 clk_disable_unprepare(priv->clk);
521
522err_uninit_dma:
523 xrx200_hw_cleanup(priv);
524
525 return err;
526}
527
528static int xrx200_remove(struct platform_device *pdev)
529{
530 struct xrx200_priv *priv = platform_get_drvdata(pdev);
531 struct net_device *net_dev = priv->net_dev;
532
533 /* free stack related instances */
534 netif_stop_queue(net_dev);
535 netif_napi_del(&priv->chan_tx.napi);
536 netif_napi_del(&priv->chan_rx.napi);
537
538 /* remove the actual device */
539 unregister_netdev(net_dev);
540
541 /* release the clock */
542 clk_disable_unprepare(priv->clk);
543
544 /* shut down hardware */
545 xrx200_hw_cleanup(priv);
546
547 return 0;
548}
549
550static const struct of_device_id xrx200_match[] = {
551 { .compatible = "lantiq,xrx200-net" },
552 {},
553};
554MODULE_DEVICE_TABLE(of, xrx200_match);
555
556static struct platform_driver xrx200_driver = {
557 .probe = xrx200_probe,
558 .remove = xrx200_remove,
559 .driver = {
560 .name = "lantiq,xrx200-net",
561 .of_match_table = xrx200_match,
562 },
563};
564
565module_platform_driver(xrx200_driver);
566
567MODULE_AUTHOR("John Crispin <john@phrozen.org>");
568MODULE_DESCRIPTION("Lantiq SoC XRX200 ethernet");
569MODULE_LICENSE("GPL");