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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 napi_complete(&ch->napi);
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 while (pkts < budget) {
249 struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->tx_free];
250
251 if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
252 struct sk_buff *skb = ch->skb[ch->tx_free];
253
254 pkts++;
255 bytes += skb->len;
256 ch->skb[ch->tx_free] = NULL;
257 consume_skb(skb);
258 memset(&ch->dma.desc_base[ch->tx_free], 0,
259 sizeof(struct ltq_dma_desc));
260 ch->tx_free++;
261 ch->tx_free %= LTQ_DESC_NUM;
262 } else {
263 break;
264 }
265 }
266
267 net_dev->stats.tx_packets += pkts;
268 net_dev->stats.tx_bytes += bytes;
269 netdev_completed_queue(ch->priv->net_dev, pkts, bytes);
270
271 if (pkts < budget) {
272 napi_complete(&ch->napi);
273 ltq_dma_enable_irq(&ch->dma);
274 }
275
276 return pkts;
277}
278
279static int xrx200_start_xmit(struct sk_buff *skb, struct net_device *net_dev)
280{
281 struct xrx200_priv *priv = netdev_priv(net_dev);
282 struct xrx200_chan *ch = &priv->chan_tx;
283 struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
284 u32 byte_offset;
285 dma_addr_t mapping;
286 int len;
287
288 skb->dev = net_dev;
289 if (skb_put_padto(skb, ETH_ZLEN)) {
290 net_dev->stats.tx_dropped++;
291 return NETDEV_TX_OK;
292 }
293
294 len = skb->len;
295
296 if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) || ch->skb[ch->dma.desc]) {
297 netdev_err(net_dev, "tx ring full\n");
298 netif_stop_queue(net_dev);
299 return NETDEV_TX_BUSY;
300 }
301
302 ch->skb[ch->dma.desc] = skb;
303
304 mapping = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);
305 if (unlikely(dma_mapping_error(priv->dev, mapping)))
306 goto err_drop;
307
308 /* dma needs to start on a 16 byte aligned address */
309 byte_offset = mapping % 16;
310
311 desc->addr = mapping - byte_offset;
312 /* Make sure the address is written before we give it to HW */
313 wmb();
314 desc->ctl = LTQ_DMA_OWN | LTQ_DMA_SOP | LTQ_DMA_EOP |
315 LTQ_DMA_TX_OFFSET(byte_offset) | (len & LTQ_DMA_SIZE_MASK);
316 ch->dma.desc++;
317 ch->dma.desc %= LTQ_DESC_NUM;
318 if (ch->dma.desc == ch->tx_free)
319 netif_stop_queue(net_dev);
320
321 netdev_sent_queue(net_dev, len);
322
323 return NETDEV_TX_OK;
324
325err_drop:
326 dev_kfree_skb(skb);
327 net_dev->stats.tx_dropped++;
328 net_dev->stats.tx_errors++;
329 return NETDEV_TX_OK;
330}
331
332static const struct net_device_ops xrx200_netdev_ops = {
333 .ndo_open = xrx200_open,
334 .ndo_stop = xrx200_close,
335 .ndo_start_xmit = xrx200_start_xmit,
336 .ndo_set_mac_address = eth_mac_addr,
337 .ndo_validate_addr = eth_validate_addr,
338};
339
340static irqreturn_t xrx200_dma_irq(int irq, void *ptr)
341{
342 struct xrx200_chan *ch = ptr;
343
344 ltq_dma_disable_irq(&ch->dma);
345 ltq_dma_ack_irq(&ch->dma);
346
347 napi_schedule(&ch->napi);
348
349 return IRQ_HANDLED;
350}
351
352static int xrx200_dma_init(struct xrx200_priv *priv)
353{
354 struct xrx200_chan *ch_rx = &priv->chan_rx;
355 struct xrx200_chan *ch_tx = &priv->chan_tx;
356 int ret = 0;
357 int i;
358
359 ltq_dma_init_port(DMA_PORT_ETOP);
360
361 ch_rx->dma.nr = XRX200_DMA_RX;
362 ch_rx->dma.dev = priv->dev;
363 ch_rx->priv = priv;
364
365 ltq_dma_alloc_rx(&ch_rx->dma);
366 for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
367 ch_rx->dma.desc++) {
368 ret = xrx200_alloc_skb(ch_rx);
369 if (ret)
370 goto rx_free;
371 }
372 ch_rx->dma.desc = 0;
373 ret = devm_request_irq(priv->dev, ch_rx->dma.irq, xrx200_dma_irq, 0,
374 "xrx200_net_rx", &priv->chan_rx);
375 if (ret) {
376 dev_err(priv->dev, "failed to request RX irq %d\n",
377 ch_rx->dma.irq);
378 goto rx_ring_free;
379 }
380
381 ch_tx->dma.nr = XRX200_DMA_TX;
382 ch_tx->dma.dev = priv->dev;
383 ch_tx->priv = priv;
384
385 ltq_dma_alloc_tx(&ch_tx->dma);
386 ret = devm_request_irq(priv->dev, ch_tx->dma.irq, xrx200_dma_irq, 0,
387 "xrx200_net_tx", &priv->chan_tx);
388 if (ret) {
389 dev_err(priv->dev, "failed to request TX irq %d\n",
390 ch_tx->dma.irq);
391 goto tx_free;
392 }
393
394 return ret;
395
396tx_free:
397 ltq_dma_free(&ch_tx->dma);
398
399rx_ring_free:
400 /* free the allocated RX ring */
401 for (i = 0; i < LTQ_DESC_NUM; i++) {
402 if (priv->chan_rx.skb[i])
403 dev_kfree_skb_any(priv->chan_rx.skb[i]);
404 }
405
406rx_free:
407 ltq_dma_free(&ch_rx->dma);
408 return ret;
409}
410
411static void xrx200_hw_cleanup(struct xrx200_priv *priv)
412{
413 int i;
414
415 ltq_dma_free(&priv->chan_tx.dma);
416 ltq_dma_free(&priv->chan_rx.dma);
417
418 /* free the allocated RX ring */
419 for (i = 0; i < LTQ_DESC_NUM; i++)
420 dev_kfree_skb_any(priv->chan_rx.skb[i]);
421}
422
423static int xrx200_probe(struct platform_device *pdev)
424{
425 struct device *dev = &pdev->dev;
426 struct device_node *np = dev->of_node;
427 struct resource *res;
428 struct xrx200_priv *priv;
429 struct net_device *net_dev;
430 const u8 *mac;
431 int err;
432
433 /* alloc the network device */
434 net_dev = devm_alloc_etherdev(dev, sizeof(struct xrx200_priv));
435 if (!net_dev)
436 return -ENOMEM;
437
438 priv = netdev_priv(net_dev);
439 priv->net_dev = net_dev;
440 priv->dev = dev;
441
442 net_dev->netdev_ops = &xrx200_netdev_ops;
443 SET_NETDEV_DEV(net_dev, dev);
444 net_dev->min_mtu = ETH_ZLEN;
445 net_dev->max_mtu = XRX200_DMA_DATA_LEN;
446
447 /* load the memory ranges */
448 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
449 if (!res) {
450 dev_err(dev, "failed to get resources\n");
451 return -ENOENT;
452 }
453
454 priv->pmac_reg = devm_ioremap_resource(dev, res);
455 if (IS_ERR(priv->pmac_reg)) {
456 dev_err(dev, "failed to request and remap io ranges\n");
457 return PTR_ERR(priv->pmac_reg);
458 }
459
460 priv->chan_rx.dma.irq = platform_get_irq_byname(pdev, "rx");
461 if (priv->chan_rx.dma.irq < 0)
462 return -ENOENT;
463 priv->chan_tx.dma.irq = platform_get_irq_byname(pdev, "tx");
464 if (priv->chan_tx.dma.irq < 0)
465 return -ENOENT;
466
467 /* get the clock */
468 priv->clk = devm_clk_get(dev, NULL);
469 if (IS_ERR(priv->clk)) {
470 dev_err(dev, "failed to get clock\n");
471 return PTR_ERR(priv->clk);
472 }
473
474 mac = of_get_mac_address(np);
475 if (!IS_ERR(mac))
476 ether_addr_copy(net_dev->dev_addr, mac);
477 else
478 eth_hw_addr_random(net_dev);
479
480 /* bring up the dma engine and IP core */
481 err = xrx200_dma_init(priv);
482 if (err)
483 return err;
484
485 /* enable clock gate */
486 err = clk_prepare_enable(priv->clk);
487 if (err)
488 goto err_uninit_dma;
489
490 /* set IPG to 12 */
491 xrx200_pmac_mask(priv, PMAC_RX_IPG_MASK, 0xb, PMAC_RX_IPG);
492
493 /* enable status header, enable CRC */
494 xrx200_pmac_mask(priv, 0,
495 PMAC_HD_CTL_RST | PMAC_HD_CTL_AST | PMAC_HD_CTL_RXSH |
496 PMAC_HD_CTL_AS | PMAC_HD_CTL_AC | PMAC_HD_CTL_RC,
497 PMAC_HD_CTL);
498
499 /* setup NAPI */
500 netif_napi_add(net_dev, &priv->chan_rx.napi, xrx200_poll_rx, 32);
501 netif_napi_add(net_dev, &priv->chan_tx.napi, xrx200_tx_housekeeping, 32);
502
503 platform_set_drvdata(pdev, priv);
504
505 err = register_netdev(net_dev);
506 if (err)
507 goto err_unprepare_clk;
508
509 return 0;
510
511err_unprepare_clk:
512 clk_disable_unprepare(priv->clk);
513
514err_uninit_dma:
515 xrx200_hw_cleanup(priv);
516
517 return err;
518}
519
520static int xrx200_remove(struct platform_device *pdev)
521{
522 struct xrx200_priv *priv = platform_get_drvdata(pdev);
523 struct net_device *net_dev = priv->net_dev;
524
525 /* free stack related instances */
526 netif_stop_queue(net_dev);
527 netif_napi_del(&priv->chan_tx.napi);
528 netif_napi_del(&priv->chan_rx.napi);
529
530 /* remove the actual device */
531 unregister_netdev(net_dev);
532
533 /* release the clock */
534 clk_disable_unprepare(priv->clk);
535
536 /* shut down hardware */
537 xrx200_hw_cleanup(priv);
538
539 return 0;
540}
541
542static const struct of_device_id xrx200_match[] = {
543 { .compatible = "lantiq,xrx200-net" },
544 {},
545};
546MODULE_DEVICE_TABLE(of, xrx200_match);
547
548static struct platform_driver xrx200_driver = {
549 .probe = xrx200_probe,
550 .remove = xrx200_remove,
551 .driver = {
552 .name = "lantiq,xrx200-net",
553 .of_match_table = xrx200_match,
554 },
555};
556
557module_platform_driver(xrx200_driver);
558
559MODULE_AUTHOR("John Crispin <john@phrozen.org>");
560MODULE_DESCRIPTION("Lantiq SoC XRX200 ethernet");
561MODULE_LICENSE("GPL");