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 struct platform_device *mips_plat_dev;
  30
  31 static char mipsnet_string[] = "mipsnet";
  32
  33 /*
  34  * Copy data from the MIPSNET rx data port
  35  */
  36 static int ioiocpy_frommipsnet(struct net_device *dev, unsigned char *kdata,
  37                         int len)
  38 {
  39         uint32_t available_len = inl(mipsnet_reg_address(dev, rxDataCount));
  40         if (available_len < len)
  41                 return -EFAULT;
  42
  43         for (; len > 0; len--, kdata++) {
  44                 *kdata = inb(mipsnet_reg_address(dev, rxDataBuffer));
  45         }
  46
  47         return inl(mipsnet_reg_address(dev, rxDataCount));
  48 }
  49
  50 static inline ssize_t mipsnet_put_todevice(struct net_device *dev,
  51         struct sk_buff *skb)
  52 {
  53         int count_to_go = skb->len;
  54         char *buf_ptr = skb->data;
  55         struct mipsnet_priv *mp = netdev_priv(dev);
  56
  57         pr_debug("%s: %s(): telling MIPSNET txDataCount(%d)\n",
  58                  dev->name, __FUNCTION__, skb->len);
  59
  60         outl(skb->len, mipsnet_reg_address(dev, txDataCount));
  61
  62         pr_debug("%s: %s(): sending data to MIPSNET txDataBuffer(%d)\n",
  63                  dev->name, __FUNCTION__, skb->len);
  64
  65         for (; count_to_go; buf_ptr++, count_to_go--) {
  66                 outb(*buf_ptr, mipsnet_reg_address(dev, txDataBuffer));
  67         }
  68
  69         mp->stats.tx_packets++;
  70         mp->stats.tx_bytes += skb->len;
  71
  72         return skb->len;
  73 }
  74
  75 static int mipsnet_xmit(struct sk_buff *skb, struct net_device *dev)
  76 {
  77         pr_debug("%s:%s(): transmitting %d bytes\n",
  78                  dev->name, __FUNCTION__, skb->len);
  79
  80         /* Only one packet at a time. Once TXDONE interrupt is serviced, the
  81          * queue will be restarted.
  82          */
  83         netif_stop_queue(dev);
  84         mipsnet_put_todevice(dev, skb);
  85
  86         return 0;
  87 }
  88
  89 static inline ssize_t mipsnet_get_fromdev(struct net_device *dev, size_t count)
  90 {
  91         struct sk_buff *skb;
  92         size_t len = count;
  93         struct mipsnet_priv *mp = netdev_priv(dev);
  94
  95         if (!(skb = alloc_skb(len + 2, GFP_KERNEL))) {
  96                 mp->stats.rx_dropped++;
  97                 return -ENOMEM;
  98         }
  99
 100         skb_reserve(skb, 2);
 101         if (ioiocpy_frommipsnet(dev, skb_put(skb, len), len))
 102                 return -EFAULT;
 103
 104         skb->dev = dev;
 105         skb->protocol = eth_type_trans(skb, dev);
 106         skb->ip_summed = CHECKSUM_UNNECESSARY;
 107
 108         pr_debug("%s:%s(): pushing RXed data to kernel\n",
 109                  dev->name, __FUNCTION__);
 110         netif_rx(skb);
 111
 112         mp->stats.rx_packets++;
 113         mp->stats.rx_bytes += len;
 114
 115         return count;
 116 }
 117
 118 static irqreturn_t mipsnet_interrupt(int irq, void *dev_id)
 119 {
 120         struct net_device *dev = dev_id;
 121
 122         irqreturn_t retval = IRQ_NONE;
 123         uint64_t interruptFlags;
 124
 125         if (irq == dev->irq) {
 126                 pr_debug("%s:%s(): irq %d for device\n",
 127                          dev->name, __FUNCTION__, irq);
 128
 129                 retval = IRQ_HANDLED;
 130
 131                 interruptFlags =
 132                     inl(mipsnet_reg_address(dev, interruptControl));
 133                 pr_debug("%s:%s(): intCtl=0x%016llx\n", dev->name,
 134                          __FUNCTION__, interruptFlags);
 135
 136                 if (interruptFlags & MIPSNET_INTCTL_TXDONE) {
 137                         pr_debug("%s:%s(): got TXDone\n",
 138                                  dev->name, __FUNCTION__);
 139                         outl(MIPSNET_INTCTL_TXDONE,
 140                              mipsnet_reg_address(dev, interruptControl));
 141                         // only one packet at a time, we are done.
 142                         netif_wake_queue(dev);
 143                 } else if (interruptFlags & MIPSNET_INTCTL_RXDONE) {
 144                         pr_debug("%s:%s(): got RX data\n",
 145                                  dev->name, __FUNCTION__);
 146                         mipsnet_get_fromdev(dev,
 147                                     inl(mipsnet_reg_address(dev, rxDataCount)));
 148                         pr_debug("%s:%s(): clearing RX int\n",
 149                                  dev->name, __FUNCTION__);
 150                         outl(MIPSNET_INTCTL_RXDONE,
 151                              mipsnet_reg_address(dev, interruptControl));
 152
 153                 } else if (interruptFlags & MIPSNET_INTCTL_TESTBIT) {
 154                         pr_debug("%s:%s(): got test interrupt\n",
 155                                  dev->name, __FUNCTION__);
 156                         // TESTBIT is cleared on read.
 157                         //    And takes effect after a write with 0
 158                         outl(0, mipsnet_reg_address(dev, interruptControl));
 159                 } else {
 160                         pr_debug("%s:%s(): no valid fags 0x%016llx\n",
 161                                  dev->name, __FUNCTION__, interruptFlags);
 162                         // Maybe shared IRQ, just ignore, no clearing.
 163                         retval = IRQ_NONE;
 164                 }
 165
 166         } else {
 167                 printk(KERN_INFO "%s: %s(): irq %d for unknown device\n",
 168                        dev->name, __FUNCTION__, irq);
 169                 retval = IRQ_NONE;
 170         }
 171         return retval;
 172 }                               //mipsnet_interrupt()
 173
 174 static int mipsnet_open(struct net_device *dev)
 175 {
 176         int err;
 177         pr_debug("%s: mipsnet_open\n", dev->name);
 178
 179         err = request_irq(dev->irq, &mipsnet_interrupt,
 180                           IRQF_SHARED, dev->name, (void *) dev);
 181
 182         if (err) {
 183                 pr_debug("%s: %s(): can't get irq %d\n",
 184                          dev->name, __FUNCTION__, dev->irq);
 185                 release_region(dev->base_addr, MIPSNET_IO_EXTENT);
 186                 return err;
 187         }
 188
 189         pr_debug("%s: %s(): got IO region at 0x%04lx and irq %d for dev.\n",
 190                  dev->name, __FUNCTION__, dev->base_addr, dev->irq);
 191
 192
 193         netif_start_queue(dev);
 194
 195         // test interrupt handler
 196         outl(MIPSNET_INTCTL_TESTBIT,
 197              mipsnet_reg_address(dev, interruptControl));
 198
 199
 200         return 0;
 201 }
 202
 203 static int mipsnet_close(struct net_device *dev)
 204 {
 205         pr_debug("%s: %s()\n", dev->name, __FUNCTION__);
 206         netif_stop_queue(dev);
 207         return 0;
 208 }
 209
 210 static struct net_device_stats *mipsnet_get_stats(struct net_device *dev)
 211 {
 212         struct mipsnet_priv *mp = netdev_priv(dev);
 213
 214         return &mp->stats;
 215 }
 216
 217 static void mipsnet_set_mclist(struct net_device *dev)
 218 {
 219         // we don't do anything
 220         return;
 221 }
 222
 223 static int __init mipsnet_probe(struct device *dev)
 224 {
 225         struct net_device *netdev;
 226         int err;
 227
 228         netdev = alloc_etherdev(sizeof(struct mipsnet_priv));
 229         if (!netdev) {
 230                 err = -ENOMEM;
 231                 goto out;
 232         }
 233
 234         dev_set_drvdata(dev, netdev);
 235
 236         netdev->open                    = mipsnet_open;
 237         netdev->stop                    = mipsnet_close;
 238         netdev->hard_start_xmit         = mipsnet_xmit;
 239         netdev->get_stats               = mipsnet_get_stats;
 240         netdev->set_multicast_list      = mipsnet_set_mclist;
 241
 242         /*
 243          * TODO: probe for these or load them from PARAM
 244          */
 245         netdev->base_addr = 0x4200;
 246         netdev->irq = MIPSCPU_INT_BASE + MIPSCPU_INT_MB0 +
 247                       inl(mipsnet_reg_address(netdev, interruptInfo));
 248
 249         // Get the io region now, get irq on open()
 250         if (!request_region(netdev->base_addr, MIPSNET_IO_EXTENT, "mipsnet")) {
 251                 pr_debug("%s: %s(): IO region {start: 0x%04lux, len: %d} "
 252                          "for dev is not availble.\n", netdev->name,
 253                          __FUNCTION__, netdev->base_addr, MIPSNET_IO_EXTENT);
 254                 err = -EBUSY;
 255                 goto out_free_netdev;
 256         }
 257
 258         /*
 259          * Lacking any better mechanism to allocate a MAC address we use a
 260          * random one ...
 261          */
 262         random_ether_addr(netdev->dev_addr);
 263
 264         err = register_netdev(netdev);
 265         if (err) {
 266                 printk(KERN_ERR "MIPSNet: failed to register netdev.\n");
 267                 goto out_free_region;
 268         }
 269
 270         return 0;
 271
 272 out_free_region:
 273         release_region(netdev->base_addr, MIPSNET_IO_EXTENT);
 274
 275 out_free_netdev:
 276         free_netdev(netdev);
 277
 278 out:
 279         return err;
 280 }
 281
 282 static int __devexit mipsnet_device_remove(struct device *device)
 283 {
 284         struct net_device *dev = dev_get_drvdata(device);
 285
 286         unregister_netdev(dev);
 287         release_region(dev->base_addr, MIPSNET_IO_EXTENT);
 288         free_netdev(dev);
 289         dev_set_drvdata(device, NULL);
 290
 291         return 0;
 292 }
 293
 294 static struct device_driver mipsnet_driver = {
 295         .name   = mipsnet_string,
 296         .bus    = &platform_bus_type,
 297         .probe  = mipsnet_probe,
 298         .remove = __devexit_p(mipsnet_device_remove),
 299 };
 300
 301 static void mipsnet_platform_release(struct device *device)
 302 {
 303         struct platform_device *pldev;
 304
 305         /* free device */
 306         pldev = to_platform_device(device);
 307         kfree(pldev);
 308 }
 309
 310 static int __init mipsnet_init_module(void)
 311 {
 312         struct platform_device *pldev;
 313         int err;
 314
 315         printk(KERN_INFO "MIPSNet Ethernet driver. Version: %s. "
 316                "(c)2005 MIPS Technologies, Inc.\n", MIPSNET_VERSION);
 317
 318         if (driver_register(&mipsnet_driver)) {
 319                 printk(KERN_ERR "Driver registration failed\n");
 320                 err = -ENODEV;
 321                 goto out;
 322         }
 323
 324         if (!(pldev = kmalloc (sizeof (*pldev), GFP_KERNEL))) {
 325                 err = -ENOMEM;
 326                 goto out_unregister_driver;
 327         }
 328
 329         memset (pldev, 0, sizeof (*pldev));
 330         pldev->name             = mipsnet_string;
 331         pldev->id               = 0;
 332         pldev->dev.release      = mipsnet_platform_release;
 333
 334         if (platform_device_register(pldev)) {
 335                 err = -ENODEV;
 336                 goto out_free_pldev;
 337         }
 338
 339         if (!pldev->dev.driver) {
 340                 /*
 341                  * The driver was not bound to this device, there was
 342                  * no hardware at this address. Unregister it, as the
 343                  * release fuction will take care of freeing the
 344                  * allocated structure
 345                  */
 346                 platform_device_unregister (pldev);
 347         }
 348
 349         mips_plat_dev           = pldev;
 350
 351         return 0;
 352
 353 out_free_pldev:
 354         kfree(pldev);
 355
 356 out_unregister_driver:
 357         driver_unregister(&mipsnet_driver);
 358 out:
 359         return err;
 360 }
 361
 362 static void __exit mipsnet_exit_module(void)
 363 {
 364         pr_debug("MIPSNet Ethernet driver exiting\n");
 365
 366         driver_unregister(&mipsnet_driver);
 367 }
 368
 369 module_init(mipsnet_init_module);
 370 module_exit(mipsnet_exit_module);