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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * LiteX Liteeth Ethernet4 *5 * Copyright 2017 Joel Stanley <joel@jms.id.au>6 *7 */8 9#include <linux/etherdevice.h>10#include <linux/interrupt.h>11#include <linux/litex.h>12#include <linux/module.h>13#include <linux/of_net.h>14#include <linux/platform_device.h>15 16#define LITEETH_WRITER_SLOT 0x0017#define LITEETH_WRITER_LENGTH 0x0418#define LITEETH_WRITER_ERRORS 0x0819#define LITEETH_WRITER_EV_STATUS 0x0C20#define LITEETH_WRITER_EV_PENDING 0x1021#define LITEETH_WRITER_EV_ENABLE 0x1422#define LITEETH_READER_START 0x1823#define LITEETH_READER_READY 0x1C24#define LITEETH_READER_LEVEL 0x2025#define LITEETH_READER_SLOT 0x2426#define LITEETH_READER_LENGTH 0x2827#define LITEETH_READER_EV_STATUS 0x2C28#define LITEETH_READER_EV_PENDING 0x3029#define LITEETH_READER_EV_ENABLE 0x3430#define LITEETH_PREAMBLE_CRC 0x3831#define LITEETH_PREAMBLE_ERRORS 0x3C32#define LITEETH_CRC_ERRORS 0x4033 34#define LITEETH_PHY_CRG_RESET 0x0035#define LITEETH_MDIO_W 0x0436#define LITEETH_MDIO_R 0x0C37 38#define DRV_NAME "liteeth"39 40struct liteeth {41 void __iomem *base;42 struct net_device *netdev;43 struct device *dev;44 u32 slot_size;45 46 /* Tx */47 u32 tx_slot;48 u32 num_tx_slots;49 void __iomem *tx_base;50 51 /* Rx */52 u32 rx_slot;53 u32 num_rx_slots;54 void __iomem *rx_base;55};56 57static int liteeth_rx(struct net_device *netdev)58{59 struct liteeth *priv = netdev_priv(netdev);60 struct sk_buff *skb;61 unsigned char *data;62 u8 rx_slot;63 int len;64 65 rx_slot = litex_read8(priv->base + LITEETH_WRITER_SLOT);66 len = litex_read32(priv->base + LITEETH_WRITER_LENGTH);67 68 if (len == 0 || len > 2048)69 goto rx_drop;70 71 skb = netdev_alloc_skb_ip_align(netdev, len);72 if (!skb) {73 netdev_err(netdev, "couldn't get memory\n");74 goto rx_drop;75 }76 77 data = skb_put(skb, len);78 memcpy_fromio(data, priv->rx_base + rx_slot * priv->slot_size, len);79 skb->protocol = eth_type_trans(skb, netdev);80 81 dev_sw_netstats_rx_add(netdev, len);82 83 return netif_rx(skb);84 85rx_drop:86 netdev->stats.rx_dropped++;87 netdev->stats.rx_errors++;88 89 return NET_RX_DROP;90}91 92static irqreturn_t liteeth_interrupt(int irq, void *dev_id)93{94 struct net_device *netdev = dev_id;95 struct liteeth *priv = netdev_priv(netdev);96 u8 reg;97 98 reg = litex_read8(priv->base + LITEETH_READER_EV_PENDING);99 if (reg) {100 if (netif_queue_stopped(netdev))101 netif_wake_queue(netdev);102 litex_write8(priv->base + LITEETH_READER_EV_PENDING, reg);103 }104 105 reg = litex_read8(priv->base + LITEETH_WRITER_EV_PENDING);106 if (reg) {107 liteeth_rx(netdev);108 litex_write8(priv->base + LITEETH_WRITER_EV_PENDING, reg);109 }110 111 return IRQ_HANDLED;112}113 114static int liteeth_open(struct net_device *netdev)115{116 struct liteeth *priv = netdev_priv(netdev);117 int err;118 119 /* Clear pending events */120 litex_write8(priv->base + LITEETH_WRITER_EV_PENDING, 1);121 litex_write8(priv->base + LITEETH_READER_EV_PENDING, 1);122 123 err = request_irq(netdev->irq, liteeth_interrupt, 0, netdev->name, netdev);124 if (err) {125 netdev_err(netdev, "failed to request irq %d\n", netdev->irq);126 return err;127 }128 129 /* Enable IRQs */130 litex_write8(priv->base + LITEETH_WRITER_EV_ENABLE, 1);131 litex_write8(priv->base + LITEETH_READER_EV_ENABLE, 1);132 133 netif_carrier_on(netdev);134 netif_start_queue(netdev);135 136 return 0;137}138 139static int liteeth_stop(struct net_device *netdev)140{141 struct liteeth *priv = netdev_priv(netdev);142 143 netif_stop_queue(netdev);144 netif_carrier_off(netdev);145 146 litex_write8(priv->base + LITEETH_WRITER_EV_ENABLE, 0);147 litex_write8(priv->base + LITEETH_READER_EV_ENABLE, 0);148 149 free_irq(netdev->irq, netdev);150 151 return 0;152}153 154static netdev_tx_t liteeth_start_xmit(struct sk_buff *skb,155 struct net_device *netdev)156{157 struct liteeth *priv = netdev_priv(netdev);158 void __iomem *txbuffer;159 160 if (!litex_read8(priv->base + LITEETH_READER_READY)) {161 if (net_ratelimit())162 netdev_err(netdev, "LITEETH_READER_READY not ready\n");163 164 netif_stop_queue(netdev);165 166 return NETDEV_TX_BUSY;167 }168 169 /* Reject oversize packets */170 if (unlikely(skb->len > priv->slot_size)) {171 if (net_ratelimit())172 netdev_err(netdev, "tx packet too big\n");173 174 dev_kfree_skb_any(skb);175 netdev->stats.tx_dropped++;176 netdev->stats.tx_errors++;177 178 return NETDEV_TX_OK;179 }180 181 txbuffer = priv->tx_base + priv->tx_slot * priv->slot_size;182 memcpy_toio(txbuffer, skb->data, skb->len);183 litex_write8(priv->base + LITEETH_READER_SLOT, priv->tx_slot);184 litex_write16(priv->base + LITEETH_READER_LENGTH, skb->len);185 litex_write8(priv->base + LITEETH_READER_START, 1);186 187 dev_sw_netstats_tx_add(netdev, 1, skb->len);188 189 priv->tx_slot = (priv->tx_slot + 1) % priv->num_tx_slots;190 dev_kfree_skb_any(skb);191 192 return NETDEV_TX_OK;193}194 195static void196liteeth_get_stats64(struct net_device *netdev, struct rtnl_link_stats64 *stats)197{198 netdev_stats_to_stats64(stats, &netdev->stats);199 dev_fetch_sw_netstats(stats, netdev->tstats);200}201 202static const struct net_device_ops liteeth_netdev_ops = {203 .ndo_open = liteeth_open,204 .ndo_stop = liteeth_stop,205 .ndo_get_stats64 = liteeth_get_stats64,206 .ndo_start_xmit = liteeth_start_xmit,207};208 209static void liteeth_setup_slots(struct liteeth *priv)210{211 struct device_node *np = priv->dev->of_node;212 int err;213 214 err = of_property_read_u32(np, "litex,rx-slots", &priv->num_rx_slots);215 if (err) {216 dev_dbg(priv->dev, "unable to get litex,rx-slots, using 2\n");217 priv->num_rx_slots = 2;218 }219 220 err = of_property_read_u32(np, "litex,tx-slots", &priv->num_tx_slots);221 if (err) {222 dev_dbg(priv->dev, "unable to get litex,tx-slots, using 2\n");223 priv->num_tx_slots = 2;224 }225 226 err = of_property_read_u32(np, "litex,slot-size", &priv->slot_size);227 if (err) {228 dev_dbg(priv->dev, "unable to get litex,slot-size, using 0x800\n");229 priv->slot_size = 0x800;230 }231}232 233static int liteeth_probe(struct platform_device *pdev)234{235 struct net_device *netdev;236 void __iomem *buf_base;237 struct liteeth *priv;238 int irq, err;239 240 netdev = devm_alloc_etherdev(&pdev->dev, sizeof(*priv));241 if (!netdev)242 return -ENOMEM;243 244 SET_NETDEV_DEV(netdev, &pdev->dev);245 platform_set_drvdata(pdev, netdev);246 247 priv = netdev_priv(netdev);248 priv->netdev = netdev;249 priv->dev = &pdev->dev;250 251 netdev->tstats = devm_netdev_alloc_pcpu_stats(&pdev->dev,252 struct pcpu_sw_netstats);253 if (!netdev->tstats)254 return -ENOMEM;255 256 irq = platform_get_irq(pdev, 0);257 if (irq < 0)258 return irq;259 netdev->irq = irq;260 261 priv->base = devm_platform_ioremap_resource_byname(pdev, "mac");262 if (IS_ERR(priv->base))263 return PTR_ERR(priv->base);264 265 buf_base = devm_platform_ioremap_resource_byname(pdev, "buffer");266 if (IS_ERR(buf_base))267 return PTR_ERR(buf_base);268 269 liteeth_setup_slots(priv);270 271 /* Rx slots */272 priv->rx_base = buf_base;273 priv->rx_slot = 0;274 275 /* Tx slots come after Rx slots */276 priv->tx_base = buf_base + priv->num_rx_slots * priv->slot_size;277 priv->tx_slot = 0;278 279 err = of_get_ethdev_address(pdev->dev.of_node, netdev);280 if (err)281 eth_hw_addr_random(netdev);282 283 netdev->netdev_ops = &liteeth_netdev_ops;284 285 err = register_netdev(netdev);286 if (err) {287 dev_err(&pdev->dev, "Failed to register netdev %d\n", err);288 return err;289 }290 291 netdev_info(netdev, "irq %d slots: tx %d rx %d size %d\n",292 netdev->irq, priv->num_tx_slots, priv->num_rx_slots, priv->slot_size);293 294 return 0;295}296 297static void liteeth_remove(struct platform_device *pdev)298{299 struct net_device *netdev = platform_get_drvdata(pdev);300 301 unregister_netdev(netdev);302}303 304static const struct of_device_id liteeth_of_match[] = {305 { .compatible = "litex,liteeth" },306 { }307};308MODULE_DEVICE_TABLE(of, liteeth_of_match);309 310static struct platform_driver liteeth_driver = {311 .probe = liteeth_probe,312 .remove_new = liteeth_remove,313 .driver = {314 .name = DRV_NAME,315 .of_match_table = liteeth_of_match,316 },317};318module_platform_driver(liteeth_driver);319 320MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");321MODULE_DESCRIPTION("LiteX Liteeth Ethernet driver");322MODULE_LICENSE("GPL");323