drivers/net/mipsnet.c

   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 #define DEBUG
   8
   9 #include <linux/init.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/etherdevice.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/platform_device.h>
  16 #include <asm/io.h>
  17 #include <asm/mips-boards/simint.h>
  18
  19 #include "mipsnet.h"            /* actual device IO mapping */
  20
  21 #define MIPSNET_VERSION "2005-06-20"
  22
  23 #define mipsnet_reg_address(dev, field) (dev->base_addr + field_offset(field))
  24
  25 struct mipsnet_priv {
  26         struct net_device_stats stats;
  27 };
  28
  29 static char mipsnet_string[] = "mipsnet";
  30
  31 /*
  32  * Copy data from the MIPSNET rx data port
  33  */
  34 static int ioiocpy_frommipsnet(struct net_device *dev, unsigned char *kdata,
  35                         int len)
  36 {
  37         uint32_t available_len = inl(mipsnet_reg_address(dev, rxDataCount));
  38         if (available_len < len)
  39                 return -EFAULT;
  40
  41         for (; len > 0; len--, kdata++) {
  42                 *kdata = inb(mipsnet_reg_address(dev, rxDataBuffer));
  43         }
  44
  45         return inl(mipsnet_reg_address(dev, rxDataCount));
  46 }
  47
  48 static inline ssize_t mipsnet_put_todevice(struct net_device *dev,
  49         struct sk_buff *skb)
  50 {
  51         int count_to_go = skb->len;
  52         char *buf_ptr = skb->data;
  53         struct mipsnet_priv *mp = netdev_priv(dev);
  54
  55         pr_debug("%s: %s(): telling MIPSNET txDataCount(%d)\n",
  56                  dev->name, __FUNCTION__, skb->len);
  57
  58         outl(skb->len, mipsnet_reg_address(dev, txDataCount));
  59
  60         pr_debug("%s: %s(): sending data to MIPSNET txDataBuffer(%d)\n",
  61                  dev->name, __FUNCTION__, skb->len);
  62
  63         for (; count_to_go; buf_ptr++, count_to_go--) {
  64                 outb(*buf_ptr, mipsnet_reg_address(dev, txDataBuffer));
  65         }
  66
  67         mp->stats.tx_packets++;
  68         mp->stats.tx_bytes += skb->len;
  69
  70         return skb->len;
  71 }
  72
  73 static int mipsnet_xmit(struct sk_buff *skb, struct net_device *dev)
  74 {
  75         pr_debug("%s:%s(): transmitting %d bytes\n",
  76                  dev->name, __FUNCTION__, skb->len);
  77
  78         /* Only one packet at a time. Once TXDONE interrupt is serviced, the
  79          * queue will be restarted.
  80          */
  81         netif_stop_queue(dev);
  82         mipsnet_put_todevice(dev, skb);
  83
  84         return 0;
  85 }
  86
  87 static inline ssize_t mipsnet_get_fromdev(struct net_device *dev, size_t count)
  88 {
  89         struct sk_buff *skb;
  90         size_t len = count;
  91         struct mipsnet_priv *mp = netdev_priv(dev);
  92
  93         if (!(skb = alloc_skb(len + 2, GFP_KERNEL))) {
  94                 mp->stats.rx_dropped++;
  95                 return -ENOMEM;
  96         }
  97
  98         skb_reserve(skb, 2);
  99         if (ioiocpy_frommipsnet(dev, skb_put(skb, len), len))
 100                 return -EFAULT;
 101
 102         skb->protocol = eth_type_trans(skb, dev);
 103         skb->ip_summed = CHECKSUM_UNNECESSARY;
 104
 105         pr_debug("%s:%s(): pushing RXed data to kernel\n",
 106                  dev->name, __FUNCTION__);
 107         netif_rx(skb);
 108
 109         mp->stats.rx_packets++;
 110         mp->stats.rx_bytes += len;
 111
 112         return count;
 113 }
 114
 115 static irqreturn_t mipsnet_interrupt(int irq, void *dev_id)
 116 {
 117         struct net_device *dev = dev_id;
 118
 119         irqreturn_t retval = IRQ_NONE;
 120         uint64_t interruptFlags;
 121
 122         if (irq == dev->irq) {
 123                 pr_debug("%s:%s(): irq %d for device\n",
 124                          dev->name, __FUNCTION__, irq);
 125
 126                 retval = IRQ_HANDLED;
 127
 128                 interruptFlags =
 129                     inl(mipsnet_reg_address(dev, interruptControl));
 130                 pr_debug("%s:%s(): intCtl=0x%016llx\n", dev->name,
 131                          __FUNCTION__, interruptFlags);
 132
 133                 if (interruptFlags & MIPSNET_INTCTL_TXDONE) {
 134                         pr_debug("%s:%s(): got TXDone\n",
 135                                  dev->name, __FUNCTION__);
 136                         outl(MIPSNET_INTCTL_TXDONE,
 137                              mipsnet_reg_address(dev, interruptControl));
 138                         // only one packet at a time, we are done.
 139                         netif_wake_queue(dev);
 140                 } else if (interruptFlags & MIPSNET_INTCTL_RXDONE) {
 141                         pr_debug("%s:%s(): got RX data\n",
 142                                  dev->name, __FUNCTION__);
 143                         mipsnet_get_fromdev(dev,
 144                                     inl(mipsnet_reg_address(dev, rxDataCount)));
 145                         pr_debug("%s:%s(): clearing RX int\n",
 146                                  dev->name, __FUNCTION__);
 147                         outl(MIPSNET_INTCTL_RXDONE,
 148                              mipsnet_reg_address(dev, interruptControl));
 149
 150                 } else if (interruptFlags & MIPSNET_INTCTL_TESTBIT) {
 151                         pr_debug("%s:%s(): got test interrupt\n",
 152                                  dev->name, __FUNCTION__);
 153                         // TESTBIT is cleared on read.
 154                         //    And takes effect after a write with 0
 155                         outl(0, mipsnet_reg_address(dev, interruptControl));
 156                 } else {
 157                         pr_debug("%s:%s(): no valid fags 0x%016llx\n",
 158                                  dev->name, __FUNCTION__, interruptFlags);
 159                         // Maybe shared IRQ, just ignore, no clearing.
 160                         retval = IRQ_NONE;
 161                 }
 162
 163         } else {
 164                 printk(KERN_INFO "%s: %s(): irq %d for unknown device\n",
 165                        dev->name, __FUNCTION__, irq);
 166                 retval = IRQ_NONE;
 167         }
 168         return retval;
 169 }                               //mipsnet_interrupt()
 170
 171 static int mipsnet_open(struct net_device *dev)
 172 {
 173         int err;
 174         pr_debug("%s: mipsnet_open\n", dev->name);
 175
 176         err = request_irq(dev->irq, &mipsnet_interrupt,
 177                           IRQF_SHARED, dev->name, (void *) dev);
 178
 179         if (err) {
 180                 pr_debug("%s: %s(): can't get irq %d\n",
 181                          dev->name, __FUNCTION__, dev->irq);
 182                 release_region(dev->base_addr, MIPSNET_IO_EXTENT);
 183                 return err;
 184         }
 185
 186         pr_debug("%s: %s(): got IO region at 0x%04lx and irq %d for dev.\n",
 187                  dev->name, __FUNCTION__, dev->base_addr, dev->irq);
 188
 189
 190         netif_start_queue(dev);
 191
 192         // test interrupt handler
 193         outl(MIPSNET_INTCTL_TESTBIT,
 194              mipsnet_reg_address(dev, interruptControl));
 195
 196
 197         return 0;
 198 }
 199
 200 static int mipsnet_close(struct net_device *dev)
 201 {
 202         pr_debug("%s: %s()\n", dev->name, __FUNCTION__);
 203         netif_stop_queue(dev);
 204         return 0;
 205 }
 206
 207 static struct net_device_stats *mipsnet_get_stats(struct net_device *dev)
 208 {
 209         struct mipsnet_priv *mp = netdev_priv(dev);
 210
 211         return &mp->stats;
 212 }
 213
 214 static void mipsnet_set_mclist(struct net_device *dev)
 215 {
 216         // we don't do anything
 217         return;
 218 }
 219
 220 static int __init mipsnet_probe(struct device *dev)
 221 {
 222         struct net_device *netdev;
 223         int err;
 224
 225         netdev = alloc_etherdev(sizeof(struct mipsnet_priv));
 226         if (!netdev) {
 227                 err = -ENOMEM;
 228                 goto out;
 229         }
 230
 231         dev_set_drvdata(dev, netdev);
 232
 233         netdev->open                    = mipsnet_open;
 234         netdev->stop                    = mipsnet_close;
 235         netdev->hard_start_xmit         = mipsnet_xmit;
 236         netdev->get_stats               = mipsnet_get_stats;
 237         netdev->set_multicast_list      = mipsnet_set_mclist;
 238
 239         /*
 240          * TODO: probe for these or load them from PARAM
 241          */
 242         netdev->base_addr = 0x4200;
 243         netdev->irq = MIPS_CPU_IRQ_BASE + MIPSCPU_INT_MB0 +
 244                       inl(mipsnet_reg_address(netdev, interruptInfo));
 245
 246         // Get the io region now, get irq on open()
 247         if (!request_region(netdev->base_addr, MIPSNET_IO_EXTENT, "mipsnet")) {
 248                 pr_debug("%s: %s(): IO region {start: 0x%04lux, len: %d} "
 249                          "for dev is not availble.\n", netdev->name,
 250                          __FUNCTION__, netdev->base_addr, MIPSNET_IO_EXTENT);
 251                 err = -EBUSY;
 252                 goto out_free_netdev;
 253         }
 254
 255         /*
 256          * Lacking any better mechanism to allocate a MAC address we use a
 257          * random one ...
 258          */
 259         random_ether_addr(netdev->dev_addr);
 260
 261         err = register_netdev(netdev);
 262         if (err) {
 263                 printk(KERN_ERR "MIPSNet: failed to register netdev.\n");
 264                 goto out_free_region;
 265         }
 266
 267         return 0;
 268
 269 out_free_region:
 270         release_region(netdev->base_addr, MIPSNET_IO_EXTENT);
 271
 272 out_free_netdev:
 273         free_netdev(netdev);
 274
 275 out:
 276         return err;
 277 }
 278
 279 static int __devexit mipsnet_device_remove(struct device *device)
 280 {
 281         struct net_device *dev = dev_get_drvdata(device);
 282
 283         unregister_netdev(dev);
 284         release_region(dev->base_addr, MIPSNET_IO_EXTENT);
 285         free_netdev(dev);
 286         dev_set_drvdata(device, NULL);
 287
 288         return 0;
 289 }
 290
 291 static struct device_driver mipsnet_driver = {
 292         .name   = mipsnet_string,
 293         .bus    = &platform_bus_type,
 294         .probe  = mipsnet_probe,
 295         .remove = __devexit_p(mipsnet_device_remove),
 296 };
 297
 298 static int __init mipsnet_init_module(void)
 299 {
 300         int err;
 301
 302         printk(KERN_INFO "MIPSNet Ethernet driver. Version: %s. "
 303                "(c)2005 MIPS Technologies, Inc.\n", MIPSNET_VERSION);
 304
 305         err = driver_register(&mipsnet_driver);
 306         if (err)
 307                 printk(KERN_ERR "Driver registration failed\n");
 308
 309         return err;
 310 }
 311
 312 static void __exit mipsnet_exit_module(void)
 313 {
 314         pr_debug("MIPSNet Ethernet driver exiting\n");
 315
 316         driver_unregister(&mipsnet_driver);
 317 }
 318
 319 module_init(mipsnet_init_module);
 320 module_exit(mipsnet_exit_module);