| 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file "COPYING" in the main directory of this archive |
| 4 | * for more details. |
| 5 | */ |
| 6 | |
| 7 | #include <linux/init.h> |
| 8 | #include <linux/io.h> |
| 9 | #include <linux/kernel.h> |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/netdevice.h> |
| 12 | #include <linux/etherdevice.h> |
| 13 | #include <linux/platform_device.h> |
| 14 | #include <asm/mips-boards/simint.h> |
| 15 | |
| 16 | #define MIPSNET_VERSION "2007-11-17" |
| 17 | |
| 18 | /* |
| 19 | * Net status/control block as seen by sw in the core. |
| 20 | */ |
| 21 | struct mipsnet_regs { |
| 22 | /* |
| 23 | * Device info for probing, reads as MIPSNET%d where %d is some |
| 24 | * form of version. |
| 25 | */ |
| 26 | u64 devId; /*0x00 */ |
| 27 | |
| 28 | /* |
| 29 | * read only busy flag. |
| 30 | * Set and cleared by the Net Device to indicate that an rx or a tx |
| 31 | * is in progress. |
| 32 | */ |
| 33 | u32 busy; /*0x08 */ |
| 34 | |
| 35 | /* |
| 36 | * Set by the Net Device. |
| 37 | * The device will set it once data has been received. |
| 38 | * The value is the number of bytes that should be read from |
| 39 | * rxDataBuffer. The value will decrease till 0 until all the data |
| 40 | * from rxDataBuffer has been read. |
| 41 | */ |
| 42 | u32 rxDataCount; /*0x0c */ |
| 43 | #define MIPSNET_MAX_RXTX_DATACOUNT (1 << 16) |
| 44 | |
| 45 | /* |
| 46 | * Settable from the MIPS core, cleared by the Net Device. |
| 47 | * The core should set the number of bytes it wants to send, |
| 48 | * then it should write those bytes of data to txDataBuffer. |
| 49 | * The device will clear txDataCount has been processed (not |
| 50 | * necessarily sent). |
| 51 | */ |
| 52 | u32 txDataCount; /*0x10 */ |
| 53 | |
| 54 | /* |
| 55 | * Interrupt control |
| 56 | * |
| 57 | * Used to clear the interrupted generated by this dev. |
| 58 | * Write a 1 to clear the interrupt. (except bit31). |
| 59 | * |
| 60 | * Bit0 is set if it was a tx-done interrupt. |
| 61 | * Bit1 is set when new rx-data is available. |
| 62 | * Until this bit is cleared there will be no other RXs. |
| 63 | * |
| 64 | * Bit31 is used for testing, it clears after a read. |
| 65 | * Writing 1 to this bit will cause an interrupt to be generated. |
| 66 | * To clear the test interrupt, write 0 to this register. |
| 67 | */ |
| 68 | u32 interruptControl; /*0x14 */ |
| 69 | #define MIPSNET_INTCTL_TXDONE (1u << 0) |
| 70 | #define MIPSNET_INTCTL_RXDONE (1u << 1) |
| 71 | #define MIPSNET_INTCTL_TESTBIT (1u << 31) |
| 72 | |
| 73 | /* |
| 74 | * Readonly core-specific interrupt info for the device to signal |
| 75 | * the core. The meaning of the contents of this field might change. |
| 76 | */ |
| 77 | /* XXX: the whole memIntf interrupt scheme is messy: the device |
| 78 | * should have no control what so ever of what VPE/register set is |
| 79 | * being used. |
| 80 | * The MemIntf should only expose interrupt lines, and something in |
| 81 | * the config should be responsible for the line<->core/vpe bindings. |
| 82 | */ |
| 83 | u32 interruptInfo; /*0x18 */ |
| 84 | |
| 85 | /* |
| 86 | * This is where the received data is read out. |
| 87 | * There is more data to read until rxDataReady is 0. |
| 88 | * Only 1 byte at this regs offset is used. |
| 89 | */ |
| 90 | u32 rxDataBuffer; /*0x1c */ |
| 91 | |
| 92 | /* |
| 93 | * This is where the data to transmit is written. |
| 94 | * Data should be written for the amount specified in the |
| 95 | * txDataCount register. |
| 96 | * Only 1 byte at this regs offset is used. |
| 97 | */ |
| 98 | u32 txDataBuffer; /*0x20 */ |
| 99 | }; |
| 100 | |
| 101 | #define regaddr(dev, field) \ |
| 102 | (dev->base_addr + offsetof(struct mipsnet_regs, field)) |
| 103 | |
| 104 | static char mipsnet_string[] = "mipsnet"; |
| 105 | |
| 106 | /* |
| 107 | * Copy data from the MIPSNET rx data port |
| 108 | */ |
| 109 | static int ioiocpy_frommipsnet(struct net_device *dev, unsigned char *kdata, |
| 110 | int len) |
| 111 | { |
| 112 | for (; len > 0; len--, kdata++) |
| 113 | *kdata = inb(regaddr(dev, rxDataBuffer)); |
| 114 | |
| 115 | return inl(regaddr(dev, rxDataCount)); |
| 116 | } |
| 117 | |
| 118 | static inline void mipsnet_put_todevice(struct net_device *dev, |
| 119 | struct sk_buff *skb) |
| 120 | { |
| 121 | int count_to_go = skb->len; |
| 122 | char *buf_ptr = skb->data; |
| 123 | |
| 124 | outl(skb->len, regaddr(dev, txDataCount)); |
| 125 | |
| 126 | for (; count_to_go; buf_ptr++, count_to_go--) |
| 127 | outb(*buf_ptr, regaddr(dev, txDataBuffer)); |
| 128 | |
| 129 | dev->stats.tx_packets++; |
| 130 | dev->stats.tx_bytes += skb->len; |
| 131 | |
| 132 | dev_kfree_skb(skb); |
| 133 | } |
| 134 | |
| 135 | static int mipsnet_xmit(struct sk_buff *skb, struct net_device *dev) |
| 136 | { |
| 137 | /* |
| 138 | * Only one packet at a time. Once TXDONE interrupt is serviced, the |
| 139 | * queue will be restarted. |
| 140 | */ |
| 141 | netif_stop_queue(dev); |
| 142 | mipsnet_put_todevice(dev, skb); |
| 143 | |
| 144 | return NETDEV_TX_OK; |
| 145 | } |
| 146 | |
| 147 | static inline ssize_t mipsnet_get_fromdev(struct net_device *dev, size_t len) |
| 148 | { |
| 149 | struct sk_buff *skb; |
| 150 | |
| 151 | if (!len) |
| 152 | return len; |
| 153 | |
| 154 | skb = dev_alloc_skb(len + NET_IP_ALIGN); |
| 155 | if (!skb) { |
| 156 | dev->stats.rx_dropped++; |
| 157 | return -ENOMEM; |
| 158 | } |
| 159 | |
| 160 | skb_reserve(skb, NET_IP_ALIGN); |
| 161 | if (ioiocpy_frommipsnet(dev, skb_put(skb, len), len)) |
| 162 | return -EFAULT; |
| 163 | |
| 164 | skb->protocol = eth_type_trans(skb, dev); |
| 165 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 166 | |
| 167 | netif_rx(skb); |
| 168 | |
| 169 | dev->stats.rx_packets++; |
| 170 | dev->stats.rx_bytes += len; |
| 171 | |
| 172 | return len; |
| 173 | } |
| 174 | |
| 175 | static irqreturn_t mipsnet_interrupt(int irq, void *dev_id) |
| 176 | { |
| 177 | struct net_device *dev = dev_id; |
| 178 | u32 int_flags; |
| 179 | irqreturn_t ret = IRQ_NONE; |
| 180 | |
| 181 | if (irq != dev->irq) |
| 182 | goto out_badirq; |
| 183 | |
| 184 | /* TESTBIT is cleared on read. */ |
| 185 | int_flags = inl(regaddr(dev, interruptControl)); |
| 186 | if (int_flags & MIPSNET_INTCTL_TESTBIT) { |
| 187 | /* TESTBIT takes effect after a write with 0. */ |
| 188 | outl(0, regaddr(dev, interruptControl)); |
| 189 | ret = IRQ_HANDLED; |
| 190 | } else if (int_flags & MIPSNET_INTCTL_TXDONE) { |
| 191 | /* Only one packet at a time, we are done. */ |
| 192 | dev->stats.tx_packets++; |
| 193 | netif_wake_queue(dev); |
| 194 | outl(MIPSNET_INTCTL_TXDONE, |
| 195 | regaddr(dev, interruptControl)); |
| 196 | ret = IRQ_HANDLED; |
| 197 | } else if (int_flags & MIPSNET_INTCTL_RXDONE) { |
| 198 | mipsnet_get_fromdev(dev, inl(regaddr(dev, rxDataCount))); |
| 199 | outl(MIPSNET_INTCTL_RXDONE, regaddr(dev, interruptControl)); |
| 200 | ret = IRQ_HANDLED; |
| 201 | } |
| 202 | return ret; |
| 203 | |
| 204 | out_badirq: |
| 205 | printk(KERN_INFO "%s: %s(): irq %d for unknown device\n", |
| 206 | dev->name, __func__, irq); |
| 207 | return ret; |
| 208 | } |
| 209 | |
| 210 | static int mipsnet_open(struct net_device *dev) |
| 211 | { |
| 212 | int err; |
| 213 | |
| 214 | err = request_irq(dev->irq, &mipsnet_interrupt, |
| 215 | IRQF_SHARED, dev->name, (void *) dev); |
| 216 | if (err) { |
| 217 | release_region(dev->base_addr, sizeof(struct mipsnet_regs)); |
| 218 | return err; |
| 219 | } |
| 220 | |
| 221 | netif_start_queue(dev); |
| 222 | |
| 223 | /* test interrupt handler */ |
| 224 | outl(MIPSNET_INTCTL_TESTBIT, regaddr(dev, interruptControl)); |
| 225 | |
| 226 | return 0; |
| 227 | } |
| 228 | |
| 229 | static int mipsnet_close(struct net_device *dev) |
| 230 | { |
| 231 | netif_stop_queue(dev); |
| 232 | free_irq(dev->irq, dev); |
| 233 | return 0; |
| 234 | } |
| 235 | |
| 236 | static void mipsnet_set_mclist(struct net_device *dev) |
| 237 | { |
| 238 | } |
| 239 | |
| 240 | static const struct net_device_ops mipsnet_netdev_ops = { |
| 241 | .ndo_open = mipsnet_open, |
| 242 | .ndo_stop = mipsnet_close, |
| 243 | .ndo_start_xmit = mipsnet_xmit, |
| 244 | .ndo_set_multicast_list = mipsnet_set_mclist, |
| 245 | .ndo_change_mtu = eth_change_mtu, |
| 246 | .ndo_validate_addr = eth_validate_addr, |
| 247 | .ndo_set_mac_address = eth_mac_addr, |
| 248 | }; |
| 249 | |
| 250 | static int __init mipsnet_probe(struct platform_device *dev) |
| 251 | { |
| 252 | struct net_device *netdev; |
| 253 | int err; |
| 254 | |
| 255 | netdev = alloc_etherdev(0); |
| 256 | if (!netdev) { |
| 257 | err = -ENOMEM; |
| 258 | goto out; |
| 259 | } |
| 260 | |
| 261 | platform_set_drvdata(dev, netdev); |
| 262 | |
| 263 | netdev->netdev_ops = &mipsnet_netdev_ops; |
| 264 | |
| 265 | /* |
| 266 | * TODO: probe for these or load them from PARAM |
| 267 | */ |
| 268 | netdev->base_addr = 0x4200; |
| 269 | netdev->irq = MIPS_CPU_IRQ_BASE + MIPSCPU_INT_MB0 + |
| 270 | inl(regaddr(netdev, interruptInfo)); |
| 271 | |
| 272 | /* Get the io region now, get irq on open() */ |
| 273 | if (!request_region(netdev->base_addr, sizeof(struct mipsnet_regs), |
| 274 | "mipsnet")) { |
| 275 | err = -EBUSY; |
| 276 | goto out_free_netdev; |
| 277 | } |
| 278 | |
| 279 | /* |
| 280 | * Lacking any better mechanism to allocate a MAC address we use a |
| 281 | * random one ... |
| 282 | */ |
| 283 | random_ether_addr(netdev->dev_addr); |
| 284 | |
| 285 | err = register_netdev(netdev); |
| 286 | if (err) { |
| 287 | printk(KERN_ERR "MIPSNet: failed to register netdev.\n"); |
| 288 | goto out_free_region; |
| 289 | } |
| 290 | |
| 291 | return 0; |
| 292 | |
| 293 | out_free_region: |
| 294 | release_region(netdev->base_addr, sizeof(struct mipsnet_regs)); |
| 295 | |
| 296 | out_free_netdev: |
| 297 | free_netdev(netdev); |
| 298 | |
| 299 | out: |
| 300 | return err; |
| 301 | } |
| 302 | |
| 303 | static int __devexit mipsnet_device_remove(struct platform_device *device) |
| 304 | { |
| 305 | struct net_device *dev = platform_get_drvdata(device); |
| 306 | |
| 307 | unregister_netdev(dev); |
| 308 | release_region(dev->base_addr, sizeof(struct mipsnet_regs)); |
| 309 | free_netdev(dev); |
| 310 | platform_set_drvdata(device, NULL); |
| 311 | |
| 312 | return 0; |
| 313 | } |
| 314 | |
| 315 | static struct platform_driver mipsnet_driver = { |
| 316 | .driver = { |
| 317 | .name = mipsnet_string, |
| 318 | .owner = THIS_MODULE, |
| 319 | }, |
| 320 | .probe = mipsnet_probe, |
| 321 | .remove = __devexit_p(mipsnet_device_remove), |
| 322 | }; |
| 323 | |
| 324 | static int __init mipsnet_init_module(void) |
| 325 | { |
| 326 | int err; |
| 327 | |
| 328 | printk(KERN_INFO "MIPSNet Ethernet driver. Version: %s. " |
| 329 | "(c)2005 MIPS Technologies, Inc.\n", MIPSNET_VERSION); |
| 330 | |
| 331 | err = platform_driver_register(&mipsnet_driver); |
| 332 | if (err) |
| 333 | printk(KERN_ERR "Driver registration failed\n"); |
| 334 | |
| 335 | return err; |
| 336 | } |
| 337 | |
| 338 | static void __exit mipsnet_exit_module(void) |
| 339 | { |
| 340 | platform_driver_unregister(&mipsnet_driver); |
| 341 | } |
| 342 | |
| 343 | module_init(mipsnet_init_module); |
| 344 | module_exit(mipsnet_exit_module); |