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