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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)4 *5 * Driver for the ARC EMAC 10100 (hardware revision 5)6 *7 * Contributors:8 * Amit Bhor9 * Sameer Dhavale10 * Vineet Gupta11 */12 13#include <linux/crc32.h>14#include <linux/etherdevice.h>15#include <linux/interrupt.h>16#include <linux/io.h>17#include <linux/module.h>18#include <linux/of.h>19#include <linux/of_address.h>20#include <linux/of_irq.h>21#include <linux/of_mdio.h>22#include <linux/of_net.h>23 24#include "emac.h"25 26static void arc_emac_restart(struct net_device *ndev);27 28/**29 * arc_emac_tx_avail - Return the number of available slots in the tx ring.30 * @priv: Pointer to ARC EMAC private data structure.31 *32 * returns: the number of slots available for transmission in tx the ring.33 */34static inline int arc_emac_tx_avail(struct arc_emac_priv *priv)35{36 return (priv->txbd_dirty + TX_BD_NUM - priv->txbd_curr - 1) % TX_BD_NUM;37}38 39/**40 * arc_emac_adjust_link - Adjust the PHY link duplex.41 * @ndev: Pointer to the net_device structure.42 *43 * This function is called to change the duplex setting after auto negotiation44 * is done by the PHY.45 */46static void arc_emac_adjust_link(struct net_device *ndev)47{48 struct arc_emac_priv *priv = netdev_priv(ndev);49 struct phy_device *phy_dev = ndev->phydev;50 unsigned int reg, state_changed = 0;51 52 if (priv->link != phy_dev->link) {53 priv->link = phy_dev->link;54 state_changed = 1;55 }56 57 if (priv->speed != phy_dev->speed) {58 priv->speed = phy_dev->speed;59 state_changed = 1;60 if (priv->set_mac_speed)61 priv->set_mac_speed(priv, priv->speed);62 }63 64 if (priv->duplex != phy_dev->duplex) {65 reg = arc_reg_get(priv, R_CTRL);66 67 if (phy_dev->duplex == DUPLEX_FULL)68 reg |= ENFL_MASK;69 else70 reg &= ~ENFL_MASK;71 72 arc_reg_set(priv, R_CTRL, reg);73 priv->duplex = phy_dev->duplex;74 state_changed = 1;75 }76 77 if (state_changed)78 phy_print_status(phy_dev);79}80 81/**82 * arc_emac_get_drvinfo - Get EMAC driver information.83 * @ndev: Pointer to net_device structure.84 * @info: Pointer to ethtool_drvinfo structure.85 *86 * This implements ethtool command for getting the driver information.87 * Issue "ethtool -i ethX" under linux prompt to execute this function.88 */89static void arc_emac_get_drvinfo(struct net_device *ndev,90 struct ethtool_drvinfo *info)91{92 struct arc_emac_priv *priv = netdev_priv(ndev);93 94 strscpy(info->driver, priv->drv_name, sizeof(info->driver));95}96 97static const struct ethtool_ops arc_emac_ethtool_ops = {98 .get_drvinfo = arc_emac_get_drvinfo,99 .get_link = ethtool_op_get_link,100 .get_link_ksettings = phy_ethtool_get_link_ksettings,101 .set_link_ksettings = phy_ethtool_set_link_ksettings,102};103 104#define FIRST_OR_LAST_MASK (FIRST_MASK | LAST_MASK)105 106/**107 * arc_emac_tx_clean - clears processed by EMAC Tx BDs.108 * @ndev: Pointer to the network device.109 */110static void arc_emac_tx_clean(struct net_device *ndev)111{112 struct arc_emac_priv *priv = netdev_priv(ndev);113 struct net_device_stats *stats = &ndev->stats;114 struct device *dev = ndev->dev.parent;115 unsigned int i;116 117 for (i = 0; i < TX_BD_NUM; i++) {118 unsigned int *txbd_dirty = &priv->txbd_dirty;119 struct arc_emac_bd *txbd = &priv->txbd[*txbd_dirty];120 struct buffer_state *tx_buff = &priv->tx_buff[*txbd_dirty];121 struct sk_buff *skb = tx_buff->skb;122 unsigned int info = le32_to_cpu(txbd->info);123 124 if ((info & FOR_EMAC) || !txbd->data || !skb)125 break;126 127 if (unlikely(info & (DROP | DEFR | LTCL | UFLO))) {128 stats->tx_errors++;129 stats->tx_dropped++;130 131 if (info & DEFR)132 stats->tx_carrier_errors++;133 134 if (info & LTCL)135 stats->collisions++;136 137 if (info & UFLO)138 stats->tx_fifo_errors++;139 } else if (likely(info & FIRST_OR_LAST_MASK)) {140 stats->tx_packets++;141 stats->tx_bytes += skb->len;142 }143 144 dma_unmap_single(dev, dma_unmap_addr(tx_buff, addr),145 dma_unmap_len(tx_buff, len), DMA_TO_DEVICE);146 147 /* return the sk_buff to system */148 dev_consume_skb_irq(skb);149 150 txbd->data = 0;151 txbd->info = 0;152 tx_buff->skb = NULL;153 154 *txbd_dirty = (*txbd_dirty + 1) % TX_BD_NUM;155 }156 157 /* Ensure that txbd_dirty is visible to tx() before checking158 * for queue stopped.159 */160 smp_mb();161 162 if (netif_queue_stopped(ndev) && arc_emac_tx_avail(priv))163 netif_wake_queue(ndev);164}165 166/**167 * arc_emac_rx - processing of Rx packets.168 * @ndev: Pointer to the network device.169 * @budget: How many BDs to process on 1 call.170 *171 * returns: Number of processed BDs172 *173 * Iterate through Rx BDs and deliver received packages to upper layer.174 */175static int arc_emac_rx(struct net_device *ndev, int budget)176{177 struct arc_emac_priv *priv = netdev_priv(ndev);178 struct device *dev = ndev->dev.parent;179 unsigned int work_done;180 181 for (work_done = 0; work_done < budget; work_done++) {182 unsigned int *last_rx_bd = &priv->last_rx_bd;183 struct net_device_stats *stats = &ndev->stats;184 struct buffer_state *rx_buff = &priv->rx_buff[*last_rx_bd];185 struct arc_emac_bd *rxbd = &priv->rxbd[*last_rx_bd];186 unsigned int pktlen, info = le32_to_cpu(rxbd->info);187 struct sk_buff *skb;188 dma_addr_t addr;189 190 if (unlikely((info & OWN_MASK) == FOR_EMAC))191 break;192 193 /* Make a note that we saw a packet at this BD.194 * So next time, driver starts from this + 1195 */196 *last_rx_bd = (*last_rx_bd + 1) % RX_BD_NUM;197 198 if (unlikely((info & FIRST_OR_LAST_MASK) !=199 FIRST_OR_LAST_MASK)) {200 /* We pre-allocate buffers of MTU size so incoming201 * packets won't be split/chained.202 */203 if (net_ratelimit())204 netdev_err(ndev, "incomplete packet received\n");205 206 /* Return ownership to EMAC */207 rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);208 stats->rx_errors++;209 stats->rx_length_errors++;210 continue;211 }212 213 /* Prepare the BD for next cycle. netif_receive_skb()214 * only if new skb was allocated and mapped to avoid holes215 * in the RX fifo.216 */217 skb = netdev_alloc_skb_ip_align(ndev, EMAC_BUFFER_SIZE);218 if (unlikely(!skb)) {219 if (net_ratelimit())220 netdev_err(ndev, "cannot allocate skb\n");221 /* Return ownership to EMAC */222 rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);223 stats->rx_errors++;224 stats->rx_dropped++;225 continue;226 }227 228 addr = dma_map_single(dev, (void *)skb->data,229 EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);230 if (dma_mapping_error(dev, addr)) {231 if (net_ratelimit())232 netdev_err(ndev, "cannot map dma buffer\n");233 dev_kfree_skb(skb);234 /* Return ownership to EMAC */235 rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);236 stats->rx_errors++;237 stats->rx_dropped++;238 continue;239 }240 241 /* unmap previosly mapped skb */242 dma_unmap_single(dev, dma_unmap_addr(rx_buff, addr),243 dma_unmap_len(rx_buff, len), DMA_FROM_DEVICE);244 245 pktlen = info & LEN_MASK;246 stats->rx_packets++;247 stats->rx_bytes += pktlen;248 skb_put(rx_buff->skb, pktlen);249 rx_buff->skb->dev = ndev;250 rx_buff->skb->protocol = eth_type_trans(rx_buff->skb, ndev);251 252 netif_receive_skb(rx_buff->skb);253 254 rx_buff->skb = skb;255 dma_unmap_addr_set(rx_buff, addr, addr);256 dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE);257 258 rxbd->data = cpu_to_le32(addr);259 260 /* Make sure pointer to data buffer is set */261 wmb();262 263 /* Return ownership to EMAC */264 rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);265 }266 267 return work_done;268}269 270/**271 * arc_emac_rx_miss_handle - handle R_MISS register272 * @ndev: Pointer to the net_device structure.273 */274static void arc_emac_rx_miss_handle(struct net_device *ndev)275{276 struct arc_emac_priv *priv = netdev_priv(ndev);277 struct net_device_stats *stats = &ndev->stats;278 unsigned int miss;279 280 miss = arc_reg_get(priv, R_MISS);281 if (miss) {282 stats->rx_errors += miss;283 stats->rx_missed_errors += miss;284 priv->rx_missed_errors += miss;285 }286}287 288/**289 * arc_emac_rx_stall_check - check RX stall290 * @ndev: Pointer to the net_device structure.291 * @budget: How many BDs requested to process on 1 call.292 * @work_done: How many BDs processed293 *294 * Under certain conditions EMAC stop reception of incoming packets and295 * continuously increment R_MISS register instead of saving data into296 * provided buffer. This function detect that condition and restart297 * EMAC.298 */299static void arc_emac_rx_stall_check(struct net_device *ndev,300 int budget, unsigned int work_done)301{302 struct arc_emac_priv *priv = netdev_priv(ndev);303 struct arc_emac_bd *rxbd;304 305 if (work_done)306 priv->rx_missed_errors = 0;307 308 if (priv->rx_missed_errors && budget) {309 rxbd = &priv->rxbd[priv->last_rx_bd];310 if (le32_to_cpu(rxbd->info) & FOR_EMAC) {311 arc_emac_restart(ndev);312 priv->rx_missed_errors = 0;313 }314 }315}316 317/**318 * arc_emac_poll - NAPI poll handler.319 * @napi: Pointer to napi_struct structure.320 * @budget: How many BDs to process on 1 call.321 *322 * returns: Number of processed BDs323 */324static int arc_emac_poll(struct napi_struct *napi, int budget)325{326 struct net_device *ndev = napi->dev;327 struct arc_emac_priv *priv = netdev_priv(ndev);328 unsigned int work_done;329 330 arc_emac_tx_clean(ndev);331 arc_emac_rx_miss_handle(ndev);332 333 work_done = arc_emac_rx(ndev, budget);334 if (work_done < budget) {335 napi_complete_done(napi, work_done);336 arc_reg_or(priv, R_ENABLE, RXINT_MASK | TXINT_MASK);337 }338 339 arc_emac_rx_stall_check(ndev, budget, work_done);340 341 return work_done;342}343 344/**345 * arc_emac_intr - Global interrupt handler for EMAC.346 * @irq: irq number.347 * @dev_instance: device instance.348 *349 * returns: IRQ_HANDLED for all cases.350 *351 * ARC EMAC has only 1 interrupt line, and depending on bits raised in352 * STATUS register we may tell what is a reason for interrupt to fire.353 */354static irqreturn_t arc_emac_intr(int irq, void *dev_instance)355{356 struct net_device *ndev = dev_instance;357 struct arc_emac_priv *priv = netdev_priv(ndev);358 struct net_device_stats *stats = &ndev->stats;359 unsigned int status;360 361 status = arc_reg_get(priv, R_STATUS);362 status &= ~MDIO_MASK;363 364 /* Reset all flags except "MDIO complete" */365 arc_reg_set(priv, R_STATUS, status);366 367 if (status & (RXINT_MASK | TXINT_MASK)) {368 if (likely(napi_schedule_prep(&priv->napi))) {369 arc_reg_clr(priv, R_ENABLE, RXINT_MASK | TXINT_MASK);370 __napi_schedule(&priv->napi);371 }372 }373 374 if (status & ERR_MASK) {375 /* MSER/RXCR/RXFR/RXFL interrupt fires on corresponding376 * 8-bit error counter overrun.377 */378 379 if (status & MSER_MASK) {380 stats->rx_missed_errors += 0x100;381 stats->rx_errors += 0x100;382 priv->rx_missed_errors += 0x100;383 napi_schedule(&priv->napi);384 }385 386 if (status & RXCR_MASK) {387 stats->rx_crc_errors += 0x100;388 stats->rx_errors += 0x100;389 }390 391 if (status & RXFR_MASK) {392 stats->rx_frame_errors += 0x100;393 stats->rx_errors += 0x100;394 }395 396 if (status & RXFL_MASK) {397 stats->rx_over_errors += 0x100;398 stats->rx_errors += 0x100;399 }400 }401 402 return IRQ_HANDLED;403}404 405#ifdef CONFIG_NET_POLL_CONTROLLER406static void arc_emac_poll_controller(struct net_device *dev)407{408 disable_irq(dev->irq);409 arc_emac_intr(dev->irq, dev);410 enable_irq(dev->irq);411}412#endif413 414/**415 * arc_emac_open - Open the network device.416 * @ndev: Pointer to the network device.417 *418 * returns: 0, on success or non-zero error value on failure.419 *420 * This function sets the MAC address, requests and enables an IRQ421 * for the EMAC device and starts the Tx queue.422 * It also connects to the phy device.423 */424static int arc_emac_open(struct net_device *ndev)425{426 struct arc_emac_priv *priv = netdev_priv(ndev);427 struct phy_device *phy_dev = ndev->phydev;428 struct device *dev = ndev->dev.parent;429 int i;430 431 phy_dev->autoneg = AUTONEG_ENABLE;432 phy_dev->speed = 0;433 phy_dev->duplex = 0;434 linkmode_and(phy_dev->advertising, phy_dev->advertising,435 phy_dev->supported);436 437 priv->last_rx_bd = 0;438 439 /* Allocate and set buffers for Rx BD's */440 for (i = 0; i < RX_BD_NUM; i++) {441 dma_addr_t addr;442 unsigned int *last_rx_bd = &priv->last_rx_bd;443 struct arc_emac_bd *rxbd = &priv->rxbd[*last_rx_bd];444 struct buffer_state *rx_buff = &priv->rx_buff[*last_rx_bd];445 446 rx_buff->skb = netdev_alloc_skb_ip_align(ndev,447 EMAC_BUFFER_SIZE);448 if (unlikely(!rx_buff->skb))449 return -ENOMEM;450 451 addr = dma_map_single(dev, (void *)rx_buff->skb->data,452 EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);453 if (dma_mapping_error(dev, addr)) {454 netdev_err(ndev, "cannot dma map\n");455 dev_kfree_skb(rx_buff->skb);456 return -ENOMEM;457 }458 dma_unmap_addr_set(rx_buff, addr, addr);459 dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE);460 461 rxbd->data = cpu_to_le32(addr);462 463 /* Make sure pointer to data buffer is set */464 wmb();465 466 /* Return ownership to EMAC */467 rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);468 469 *last_rx_bd = (*last_rx_bd + 1) % RX_BD_NUM;470 }471 472 priv->txbd_curr = 0;473 priv->txbd_dirty = 0;474 475 /* Clean Tx BD's */476 memset(priv->txbd, 0, TX_RING_SZ);477 478 /* Initialize logical address filter */479 arc_reg_set(priv, R_LAFL, 0);480 arc_reg_set(priv, R_LAFH, 0);481 482 /* Set BD ring pointers for device side */483 arc_reg_set(priv, R_RX_RING, (unsigned int)priv->rxbd_dma);484 arc_reg_set(priv, R_TX_RING, (unsigned int)priv->txbd_dma);485 486 /* Enable interrupts */487 arc_reg_set(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);488 489 /* Set CONTROL */490 arc_reg_set(priv, R_CTRL,491 (RX_BD_NUM << 24) | /* RX BD table length */492 (TX_BD_NUM << 16) | /* TX BD table length */493 TXRN_MASK | RXRN_MASK);494 495 napi_enable(&priv->napi);496 497 /* Enable EMAC */498 arc_reg_or(priv, R_CTRL, EN_MASK);499 500 phy_start(ndev->phydev);501 502 netif_start_queue(ndev);503 504 return 0;505}506 507/**508 * arc_emac_set_rx_mode - Change the receive filtering mode.509 * @ndev: Pointer to the network device.510 *511 * This function enables/disables promiscuous or all-multicast mode512 * and updates the multicast filtering list of the network device.513 */514static void arc_emac_set_rx_mode(struct net_device *ndev)515{516 struct arc_emac_priv *priv = netdev_priv(ndev);517 518 if (ndev->flags & IFF_PROMISC) {519 arc_reg_or(priv, R_CTRL, PROM_MASK);520 } else {521 arc_reg_clr(priv, R_CTRL, PROM_MASK);522 523 if (ndev->flags & IFF_ALLMULTI) {524 arc_reg_set(priv, R_LAFL, ~0);525 arc_reg_set(priv, R_LAFH, ~0);526 } else if (ndev->flags & IFF_MULTICAST) {527 struct netdev_hw_addr *ha;528 unsigned int filter[2] = { 0, 0 };529 int bit;530 531 netdev_for_each_mc_addr(ha, ndev) {532 bit = ether_crc_le(ETH_ALEN, ha->addr) >> 26;533 filter[bit >> 5] |= 1 << (bit & 31);534 }535 536 arc_reg_set(priv, R_LAFL, filter[0]);537 arc_reg_set(priv, R_LAFH, filter[1]);538 } else {539 arc_reg_set(priv, R_LAFL, 0);540 arc_reg_set(priv, R_LAFH, 0);541 }542 }543}544 545/**546 * arc_free_tx_queue - free skb from tx queue547 * @ndev: Pointer to the network device.548 *549 * This function must be called while EMAC disable550 */551static void arc_free_tx_queue(struct net_device *ndev)552{553 struct arc_emac_priv *priv = netdev_priv(ndev);554 struct device *dev = ndev->dev.parent;555 unsigned int i;556 557 for (i = 0; i < TX_BD_NUM; i++) {558 struct arc_emac_bd *txbd = &priv->txbd[i];559 struct buffer_state *tx_buff = &priv->tx_buff[i];560 561 if (tx_buff->skb) {562 dma_unmap_single(dev,563 dma_unmap_addr(tx_buff, addr),564 dma_unmap_len(tx_buff, len),565 DMA_TO_DEVICE);566 567 /* return the sk_buff to system */568 dev_kfree_skb_irq(tx_buff->skb);569 }570 571 txbd->info = 0;572 txbd->data = 0;573 tx_buff->skb = NULL;574 }575}576 577/**578 * arc_free_rx_queue - free skb from rx queue579 * @ndev: Pointer to the network device.580 *581 * This function must be called while EMAC disable582 */583static void arc_free_rx_queue(struct net_device *ndev)584{585 struct arc_emac_priv *priv = netdev_priv(ndev);586 struct device *dev = ndev->dev.parent;587 unsigned int i;588 589 for (i = 0; i < RX_BD_NUM; i++) {590 struct arc_emac_bd *rxbd = &priv->rxbd[i];591 struct buffer_state *rx_buff = &priv->rx_buff[i];592 593 if (rx_buff->skb) {594 dma_unmap_single(dev,595 dma_unmap_addr(rx_buff, addr),596 dma_unmap_len(rx_buff, len),597 DMA_FROM_DEVICE);598 599 /* return the sk_buff to system */600 dev_kfree_skb_irq(rx_buff->skb);601 }602 603 rxbd->info = 0;604 rxbd->data = 0;605 rx_buff->skb = NULL;606 }607}608 609/**610 * arc_emac_stop - Close the network device.611 * @ndev: Pointer to the network device.612 *613 * This function stops the Tx queue, disables interrupts and frees the IRQ for614 * the EMAC device.615 * It also disconnects the PHY device associated with the EMAC device.616 */617static int arc_emac_stop(struct net_device *ndev)618{619 struct arc_emac_priv *priv = netdev_priv(ndev);620 621 napi_disable(&priv->napi);622 netif_stop_queue(ndev);623 624 phy_stop(ndev->phydev);625 626 /* Disable interrupts */627 arc_reg_clr(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);628 629 /* Disable EMAC */630 arc_reg_clr(priv, R_CTRL, EN_MASK);631 632 /* Return the sk_buff to system */633 arc_free_tx_queue(ndev);634 arc_free_rx_queue(ndev);635 636 return 0;637}638 639/**640 * arc_emac_stats - Get system network statistics.641 * @ndev: Pointer to net_device structure.642 *643 * Returns the address of the device statistics structure.644 * Statistics are updated in interrupt handler.645 */646static struct net_device_stats *arc_emac_stats(struct net_device *ndev)647{648 struct arc_emac_priv *priv = netdev_priv(ndev);649 struct net_device_stats *stats = &ndev->stats;650 unsigned long miss, rxerr;651 u8 rxcrc, rxfram, rxoflow;652 653 rxerr = arc_reg_get(priv, R_RXERR);654 miss = arc_reg_get(priv, R_MISS);655 656 rxcrc = rxerr;657 rxfram = rxerr >> 8;658 rxoflow = rxerr >> 16;659 660 stats->rx_errors += miss;661 stats->rx_errors += rxcrc + rxfram + rxoflow;662 663 stats->rx_over_errors += rxoflow;664 stats->rx_frame_errors += rxfram;665 stats->rx_crc_errors += rxcrc;666 stats->rx_missed_errors += miss;667 668 return stats;669}670 671/**672 * arc_emac_tx - Starts the data transmission.673 * @skb: sk_buff pointer that contains data to be Transmitted.674 * @ndev: Pointer to net_device structure.675 *676 * returns: NETDEV_TX_OK, on success677 * NETDEV_TX_BUSY, if any of the descriptors are not free.678 *679 * This function is invoked from upper layers to initiate transmission.680 */681static netdev_tx_t arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)682{683 struct arc_emac_priv *priv = netdev_priv(ndev);684 unsigned int len, *txbd_curr = &priv->txbd_curr;685 struct net_device_stats *stats = &ndev->stats;686 __le32 *info = &priv->txbd[*txbd_curr].info;687 struct device *dev = ndev->dev.parent;688 dma_addr_t addr;689 690 if (skb_padto(skb, ETH_ZLEN))691 return NETDEV_TX_OK;692 693 len = max_t(unsigned int, ETH_ZLEN, skb->len);694 695 if (unlikely(!arc_emac_tx_avail(priv))) {696 netif_stop_queue(ndev);697 netdev_err(ndev, "BUG! Tx Ring full when queue awake!\n");698 return NETDEV_TX_BUSY;699 }700 701 addr = dma_map_single(dev, (void *)skb->data, len, DMA_TO_DEVICE);702 703 if (unlikely(dma_mapping_error(dev, addr))) {704 stats->tx_dropped++;705 stats->tx_errors++;706 dev_kfree_skb_any(skb);707 return NETDEV_TX_OK;708 }709 dma_unmap_addr_set(&priv->tx_buff[*txbd_curr], addr, addr);710 dma_unmap_len_set(&priv->tx_buff[*txbd_curr], len, len);711 712 priv->txbd[*txbd_curr].data = cpu_to_le32(addr);713 714 /* Make sure pointer to data buffer is set */715 wmb();716 717 skb_tx_timestamp(skb);718 719 *info = cpu_to_le32(FOR_EMAC | FIRST_OR_LAST_MASK | len);720 721 /* Make sure info word is set */722 wmb();723 724 priv->tx_buff[*txbd_curr].skb = skb;725 726 /* Increment index to point to the next BD */727 *txbd_curr = (*txbd_curr + 1) % TX_BD_NUM;728 729 /* Ensure that tx_clean() sees the new txbd_curr before730 * checking the queue status. This prevents an unneeded wake731 * of the queue in tx_clean().732 */733 smp_mb();734 735 if (!arc_emac_tx_avail(priv)) {736 netif_stop_queue(ndev);737 /* Refresh tx_dirty */738 smp_mb();739 if (arc_emac_tx_avail(priv))740 netif_start_queue(ndev);741 }742 743 arc_reg_set(priv, R_STATUS, TXPL_MASK);744 745 return NETDEV_TX_OK;746}747 748static void arc_emac_set_address_internal(struct net_device *ndev)749{750 struct arc_emac_priv *priv = netdev_priv(ndev);751 unsigned int addr_low, addr_hi;752 753 addr_low = le32_to_cpu(*(__le32 *)&ndev->dev_addr[0]);754 addr_hi = le16_to_cpu(*(__le16 *)&ndev->dev_addr[4]);755 756 arc_reg_set(priv, R_ADDRL, addr_low);757 arc_reg_set(priv, R_ADDRH, addr_hi);758}759 760/**761 * arc_emac_set_address - Set the MAC address for this device.762 * @ndev: Pointer to net_device structure.763 * @p: 6 byte Address to be written as MAC address.764 *765 * This function copies the HW address from the sockaddr structure to the766 * net_device structure and updates the address in HW.767 *768 * returns: -EBUSY if the net device is busy or 0 if the address is set769 * successfully.770 */771static int arc_emac_set_address(struct net_device *ndev, void *p)772{773 struct sockaddr *addr = p;774 775 if (netif_running(ndev))776 return -EBUSY;777 778 if (!is_valid_ether_addr(addr->sa_data))779 return -EADDRNOTAVAIL;780 781 eth_hw_addr_set(ndev, addr->sa_data);782 783 arc_emac_set_address_internal(ndev);784 785 return 0;786}787 788/**789 * arc_emac_restart - Restart EMAC790 * @ndev: Pointer to net_device structure.791 *792 * This function do hardware reset of EMAC in order to restore793 * network packets reception.794 */795static void arc_emac_restart(struct net_device *ndev)796{797 struct arc_emac_priv *priv = netdev_priv(ndev);798 struct net_device_stats *stats = &ndev->stats;799 int i;800 801 if (net_ratelimit())802 netdev_warn(ndev, "restarting stalled EMAC\n");803 804 netif_stop_queue(ndev);805 806 /* Disable interrupts */807 arc_reg_clr(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);808 809 /* Disable EMAC */810 arc_reg_clr(priv, R_CTRL, EN_MASK);811 812 /* Return the sk_buff to system */813 arc_free_tx_queue(ndev);814 815 /* Clean Tx BD's */816 priv->txbd_curr = 0;817 priv->txbd_dirty = 0;818 memset(priv->txbd, 0, TX_RING_SZ);819 820 for (i = 0; i < RX_BD_NUM; i++) {821 struct arc_emac_bd *rxbd = &priv->rxbd[i];822 unsigned int info = le32_to_cpu(rxbd->info);823 824 if (!(info & FOR_EMAC)) {825 stats->rx_errors++;826 stats->rx_dropped++;827 }828 /* Return ownership to EMAC */829 rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);830 }831 priv->last_rx_bd = 0;832 833 /* Make sure info is visible to EMAC before enable */834 wmb();835 836 /* Enable interrupts */837 arc_reg_set(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);838 839 /* Enable EMAC */840 arc_reg_or(priv, R_CTRL, EN_MASK);841 842 netif_start_queue(ndev);843}844 845static const struct net_device_ops arc_emac_netdev_ops = {846 .ndo_open = arc_emac_open,847 .ndo_stop = arc_emac_stop,848 .ndo_start_xmit = arc_emac_tx,849 .ndo_set_mac_address = arc_emac_set_address,850 .ndo_get_stats = arc_emac_stats,851 .ndo_set_rx_mode = arc_emac_set_rx_mode,852 .ndo_eth_ioctl = phy_do_ioctl_running,853#ifdef CONFIG_NET_POLL_CONTROLLER854 .ndo_poll_controller = arc_emac_poll_controller,855#endif856};857 858int arc_emac_probe(struct net_device *ndev, int interface)859{860 struct device *dev = ndev->dev.parent;861 struct resource res_regs;862 struct device_node *phy_node;863 struct phy_device *phydev = NULL;864 struct arc_emac_priv *priv;865 unsigned int id, clock_frequency, irq;866 int err;867 868 /* Get PHY from device tree */869 phy_node = of_parse_phandle(dev->of_node, "phy", 0);870 if (!phy_node) {871 dev_err(dev, "failed to retrieve phy description from device tree\n");872 return -ENODEV;873 }874 875 /* Get EMAC registers base address from device tree */876 err = of_address_to_resource(dev->of_node, 0, &res_regs);877 if (err) {878 dev_err(dev, "failed to retrieve registers base from device tree\n");879 err = -ENODEV;880 goto out_put_node;881 }882 883 /* Get IRQ from device tree */884 irq = irq_of_parse_and_map(dev->of_node, 0);885 if (!irq) {886 dev_err(dev, "failed to retrieve <irq> value from device tree\n");887 err = -ENODEV;888 goto out_put_node;889 }890 891 ndev->netdev_ops = &arc_emac_netdev_ops;892 ndev->ethtool_ops = &arc_emac_ethtool_ops;893 ndev->watchdog_timeo = TX_TIMEOUT;894 895 priv = netdev_priv(ndev);896 priv->dev = dev;897 898 priv->regs = devm_ioremap_resource(dev, &res_regs);899 if (IS_ERR(priv->regs)) {900 err = PTR_ERR(priv->regs);901 goto out_put_node;902 }903 904 dev_dbg(dev, "Registers base address is 0x%p\n", priv->regs);905 906 if (priv->clk) {907 err = clk_prepare_enable(priv->clk);908 if (err) {909 dev_err(dev, "failed to enable clock\n");910 goto out_put_node;911 }912 913 clock_frequency = clk_get_rate(priv->clk);914 } else {915 /* Get CPU clock frequency from device tree */916 if (of_property_read_u32(dev->of_node, "clock-frequency",917 &clock_frequency)) {918 dev_err(dev, "failed to retrieve <clock-frequency> from device tree\n");919 err = -EINVAL;920 goto out_put_node;921 }922 }923 924 id = arc_reg_get(priv, R_ID);925 926 /* Check for EMAC revision 5 or 7, magic number */927 if (!(id == 0x0005fd02 || id == 0x0007fd02)) {928 dev_err(dev, "ARC EMAC not detected, id=0x%x\n", id);929 err = -ENODEV;930 goto out_clken;931 }932 dev_info(dev, "ARC EMAC detected with id: 0x%x\n", id);933 934 /* Set poll rate so that it polls every 1 ms */935 arc_reg_set(priv, R_POLLRATE, clock_frequency / 1000000);936 937 ndev->irq = irq;938 dev_info(dev, "IRQ is %d\n", ndev->irq);939 940 /* Register interrupt handler for device */941 err = devm_request_irq(dev, ndev->irq, arc_emac_intr, 0,942 ndev->name, ndev);943 if (err) {944 dev_err(dev, "could not allocate IRQ\n");945 goto out_clken;946 }947 948 /* Get MAC address from device tree */949 err = of_get_ethdev_address(dev->of_node, ndev);950 if (err)951 eth_hw_addr_random(ndev);952 953 arc_emac_set_address_internal(ndev);954 dev_info(dev, "MAC address is now %pM\n", ndev->dev_addr);955 956 /* Do 1 allocation instead of 2 separate ones for Rx and Tx BD rings */957 priv->rxbd = dmam_alloc_coherent(dev, RX_RING_SZ + TX_RING_SZ,958 &priv->rxbd_dma, GFP_KERNEL);959 960 if (!priv->rxbd) {961 dev_err(dev, "failed to allocate data buffers\n");962 err = -ENOMEM;963 goto out_clken;964 }965 966 priv->txbd = priv->rxbd + RX_BD_NUM;967 968 priv->txbd_dma = priv->rxbd_dma + RX_RING_SZ;969 dev_dbg(dev, "EMAC Device addr: Rx Ring [0x%x], Tx Ring[%x]\n",970 (unsigned int)priv->rxbd_dma, (unsigned int)priv->txbd_dma);971 972 err = arc_mdio_probe(priv);973 if (err) {974 dev_err(dev, "failed to probe MII bus\n");975 goto out_clken;976 }977 978 phydev = of_phy_connect(ndev, phy_node, arc_emac_adjust_link, 0,979 interface);980 if (!phydev) {981 dev_err(dev, "of_phy_connect() failed\n");982 err = -ENODEV;983 goto out_mdio;984 }985 986 dev_info(dev, "connected to %s phy with id 0x%x\n",987 phydev->drv->name, phydev->phy_id);988 989 netif_napi_add_weight(ndev, &priv->napi, arc_emac_poll,990 ARC_EMAC_NAPI_WEIGHT);991 992 err = register_netdev(ndev);993 if (err) {994 dev_err(dev, "failed to register network device\n");995 goto out_netif_api;996 }997 998 of_node_put(phy_node);999 return 0;1000 1001out_netif_api:1002 netif_napi_del(&priv->napi);1003 phy_disconnect(phydev);1004out_mdio:1005 arc_mdio_remove(priv);1006out_clken:1007 if (priv->clk)1008 clk_disable_unprepare(priv->clk);1009out_put_node:1010 of_node_put(phy_node);1011 1012 return err;1013}1014EXPORT_SYMBOL_GPL(arc_emac_probe);1015 1016void arc_emac_remove(struct net_device *ndev)1017{1018 struct arc_emac_priv *priv = netdev_priv(ndev);1019 1020 phy_disconnect(ndev->phydev);1021 arc_mdio_remove(priv);1022 unregister_netdev(ndev);1023 netif_napi_del(&priv->napi);1024 1025 if (!IS_ERR(priv->clk))1026 clk_disable_unprepare(priv->clk);1027}1028EXPORT_SYMBOL_GPL(arc_emac_remove);1029 1030MODULE_AUTHOR("Alexey Brodkin <abrodkin@synopsys.com>");1031MODULE_DESCRIPTION("ARC EMAC driver");1032MODULE_LICENSE("GPL");1033