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 55 struct 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 65 struct 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 77 static u32 xrx200_pmac_r32(struct xrx200_priv *priv, u32 offset) 78 { 79 return __raw_readl(priv->pmac_reg + offset); 80 } 81 82 static void xrx200_pmac_w32(struct xrx200_priv *priv, u32 val, u32 offset) 83 { 84 __raw_writel(val, priv->pmac_reg + offset); 85 } 86 87 static 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 */ 98 static 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 } 114 115 static 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 } 139 140 static 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 } 154 155 static 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 } 175 176 skip: 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 } 183 184 static 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 } 211 212 static 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 } 239 240 static 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 } 278 279 static 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; 324 325 err_drop: 326 dev_kfree_skb(skb); 327 net_dev->stats.tx_dropped++; 328 net_dev->stats.tx_errors++; 329 return NETDEV_TX_OK; 330 } 331 332 static 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 }; 339 340 static 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 } 351 352 static 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; 395 396 tx_free: 397 ltq_dma_free(&ch_tx->dma); 398 399 rx_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 } 405 406 rx_free: 407 ltq_dma_free(&ch_rx->dma); 408 return ret; 409 } 410 411 static 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 } 422 423 static 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; 510 511 err_unprepare_clk: 512 clk_disable_unprepare(priv->clk); 513 514 err_uninit_dma: 515 xrx200_hw_cleanup(priv); 516 517 return err; 518 } 519 520 static 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 } 541 542 static const struct of_device_id xrx200_match[] = { 543 { .compatible = "lantiq,xrx200-net" }, 544 {}, 545 }; 546 MODULE_DEVICE_TABLE(of, xrx200_match); 547 548 static 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 }; 556 557 module_platform_driver(xrx200_driver); 558 559 MODULE_AUTHOR("John Crispin <john@phrozen.org>"); 560 MODULE_DESCRIPTION("Lantiq SoC XRX200 ethernet"); 561 MODULE_LICENSE("GPL"); 562