maple.c

linux 内核源代码

                       maple_add_packet(maple_dev->mq);
                       liststatus++;
               }
       }

       return 0;
}

/* VBLANK bottom half - implemented via workqueue */
static void maple_vblank_handler(struct work_struct *work)
{
       if (!maple_dma_done())
               return;
       if (!list_empty(&maple_sentq))
               return;
       ctrl_outl(0, MAPLE_ENABLE);
       liststatus = 0;
       bus_for_each_dev(&maple_bus_type, NULL, NULL,
                        setup_maple_commands);
       if (time_after(jiffies, maple_pnp_time))
               maple_pnp_time = jiffies + MAPLE_PNP_INTERVAL;
       if (liststatus && list_empty(&maple_sentq)) {
               INIT_LIST_HEAD(&maple_sentq);
               maple_send();
       }
       maplebus_dma_reset();
}

/* handle devices added via hotplugs - placing them on queue for DEVINFO*/
static void maple_map_subunits(struct maple_device *mdev, int submask)
{
       int retval, k, devcheck;
       struct maple_device *mdev_add;
       struct maple_device_specify ds;

       for (k = 0; k < 5; k++) {
               ds.port = mdev->port;
               ds.unit = k + 1;
               retval =
                   bus_for_each_dev(&maple_bus_type, NULL, &ds,
                                    detach_maple_device);
               if (retval) {
                       submask = submask >> 1;
                       continue;
               }
               devcheck = submask & 0x01;
               if (devcheck) {
                       mdev_add = maple_alloc_dev(mdev->port, k + 1);
                       if (!mdev_add)
                               return;
                       mdev_add->mq->command = MAPLE_COMMAND_DEVINFO;
                       mdev_add->mq->length = 0;
                       maple_add_packet(mdev_add->mq);
                       scanning = 1;
               }
               submask = submask >> 1;
       }
}

/* mark a device as removed */
static void maple_clean_submap(struct maple_device *mdev)
{
       int killbit;

       killbit = (mdev->unit > 0 ? (1 << (mdev->unit - 1)) & 0x1f : 0x20);
       killbit = ~killbit;
       killbit &= 0xFF;
       subdevice_map[mdev->port] = subdevice_map[mdev->port] & killbit;
}

/* handle empty port or hotplug removal */
static void maple_response_none(struct maple_device *mdev,
                               struct mapleq *mq)
{
       if (mdev->unit != 0) {
               list_del(&mq->list);
               maple_clean_submap(mdev);
               printk(KERN_INFO
                      "Maple bus device detaching at (%d, %d)\n",
                      mdev->port, mdev->unit);
               maple_detach_driver(mdev);
               return;
       }
       if (!started) {
               printk(KERN_INFO "No maple devices attached to port %d\n",
                      mdev->port);
               return;
       }
       maple_clean_submap(mdev);
}

/* preprocess hotplugs or scans */
static void maple_response_devinfo(struct maple_device *mdev,
                                  char *recvbuf)
{
       char submask;
       if ((!started) || (scanning == 2)) {
               maple_attach_driver(mdev);
               return;
       }
       if (mdev->unit == 0) {
               submask = recvbuf[2] & 0x1F;
               if (submask ^ subdevice_map[mdev->port]) {
                       maple_map_subunits(mdev, submask);
                       subdevice_map[mdev->port] = submask;
               }
       }
}

/* maple dma end bottom half - implemented via workqueue */
static void maple_dma_handler(struct work_struct *work)
{
       struct mapleq *mq, *nmq;
       struct maple_device *dev;
       char *recvbuf;
       enum maple_code code;

       if (!maple_dma_done())
               return;
       ctrl_outl(0, MAPLE_ENABLE);
       if (!list_empty(&maple_sentq)) {
               list_for_each_entry_safe(mq, nmq, &maple_sentq, list) {
                       recvbuf = mq->recvbuf;
                       code = recvbuf[0];
                       dev = mq->dev;
                       switch (code) {
                       case MAPLE_RESPONSE_NONE:
                               maple_response_none(dev, mq);
                               break;

                       case MAPLE_RESPONSE_DEVINFO:
                               maple_response_devinfo(dev, recvbuf);
                               break;

                       case MAPLE_RESPONSE_DATATRF:
                               if (dev->callback)
                                       dev->callback(mq);
                               break;

                       case MAPLE_RESPONSE_FILEERR:
                       case MAPLE_RESPONSE_AGAIN:
                       case MAPLE_RESPONSE_BADCMD:
                       case MAPLE_RESPONSE_BADFUNC:
                               printk(KERN_DEBUG
                                      "Maple non-fatal error 0x%X\n",
                                      code);
                               break;

                       case MAPLE_RESPONSE_ALLINFO:
                               printk(KERN_DEBUG
                                      "Maple - extended device information not supported\n");
                               break;

                       case MAPLE_RESPONSE_OK:
                               break;

                       default:
                               break;
                       }
               }
               INIT_LIST_HEAD(&maple_sentq);
               if (scanning == 1) {
                       maple_send();
                       scanning = 2;
               } else
                       scanning = 0;

               if (started == 0)
                       started = 1;
       }
       maplebus_dma_reset();
}

static irqreturn_t maplebus_dma_interrupt(int irq, void *dev_id)
{
       /* Load everything into the bottom half */
       schedule_work(&maple_dma_process);
       return IRQ_HANDLED;
}

static irqreturn_t maplebus_vblank_interrupt(int irq, void *dev_id)
{
       schedule_work(&maple_vblank_process);
       return IRQ_HANDLED;
}

static struct irqaction maple_dma_irq = {
       .name = "maple bus DMA handler",
       .handler = maplebus_dma_interrupt,
       .flags = IRQF_SHARED,
};

static struct irqaction maple_vblank_irq = {
       .name = "maple bus VBLANK handler",
       .handler = maplebus_vblank_interrupt,
       .flags = IRQF_SHARED,
};

static int maple_set_dma_interrupt_handler(void)
{
       return setup_irq(HW_EVENT_MAPLE_DMA, &maple_dma_irq);
}

static int maple_set_vblank_interrupt_handler(void)
{
       return setup_irq(HW_EVENT_VSYNC, &maple_vblank_irq);
}

static int maple_get_dma_buffer(void)
{
       maple_sendbuf =
           (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
                                     MAPLE_DMA_PAGES);
       if (!maple_sendbuf)
               return -ENOMEM;
       return 0;
}

static int match_maple_bus_driver(struct device *devptr,
                                 struct device_driver *drvptr)
{
       struct maple_driver *maple_drv;
       struct maple_device *maple_dev;

       maple_drv = container_of(drvptr, struct maple_driver, drv);
       maple_dev = container_of(devptr, struct maple_device, dev);
       /* Trap empty port case */
       if (maple_dev->devinfo.function == 0xFFFFFFFF)
               return 0;
       else if (maple_dev->devinfo.function &
                be32_to_cpu(maple_drv->function))
               return 1;
       return 0;
}

static int maple_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
{
       return 0;
}

static void maple_bus_release(struct device *dev)
{
}

static struct maple_driver maple_dummy_driver = {
       .drv = {
               .name = "maple_dummy_driver",
               .bus =  &maple_bus_type,
       },
};

struct bus_type maple_bus_type = {
       .name =         "maple",
       .match =        match_maple_bus_driver,
       .uevent =       maple_bus_uevent,
};
EXPORT_SYMBOL_GPL(maple_bus_type);

static struct device maple_bus = {
       .bus_id = "maple",
       .release = maple_bus_release,
};

static int __init maple_bus_init(void)
{
       int retval, i;
       struct maple_device *mdev[MAPLE_PORTS];
       ctrl_outl(0, MAPLE_STATE);

       retval = device_register(&maple_bus);
       if (retval)
               goto cleanup;

       retval = bus_register(&maple_bus_type);
       if (retval)
               goto cleanup_device;

       retval = driver_register(&maple_dummy_driver.drv);

       if (retval)
               goto cleanup_bus;

       /* allocate memory for maple bus dma */
       retval = maple_get_dma_buffer();
       if (retval) {
               printk(KERN_INFO
                      "Maple bus: Failed to allocate Maple DMA buffers\n");
               goto cleanup_basic;
       }

       /* set up DMA interrupt handler */
       retval = maple_set_dma_interrupt_handler();
       if (retval) {
               printk(KERN_INFO
                      "Maple bus: Failed to grab maple DMA IRQ\n");
               goto cleanup_dma;
       }

       /* set up VBLANK interrupt handler */
       retval = maple_set_vblank_interrupt_handler();
       if (retval) {
               printk(KERN_INFO "Maple bus: Failed to grab VBLANK IRQ\n");
               goto cleanup_irq;
       }

       maple_queue_cache =
           kmem_cache_create("maple_queue_cache", 0x400, 0,
                             SLAB_HWCACHE_ALIGN, NULL);

       if (!maple_queue_cache)
               goto cleanup_bothirqs;

       /* setup maple ports */
       for (i = 0; i < MAPLE_PORTS; i++) {
               mdev[i] = maple_alloc_dev(i, 0);
               if (!mdev[i]) {
                       while (i-- > 0)
                               maple_free_dev(mdev[i]);
                       goto cleanup_cache;
               }
               mdev[i]->registered = 0;
               mdev[i]->mq->command = MAPLE_COMMAND_DEVINFO;
               mdev[i]->mq->length = 0;
               maple_attach_driver(mdev[i]);
               maple_add_packet(mdev[i]->mq);
               subdevice_map[i] = 0;
       }

       /* setup maplebus hardware */
       maplebus_dma_reset();

       /* initial detection */
       maple_send();

       maple_pnp_time = jiffies;

       printk(KERN_INFO "Maple bus core now registered.\n");

       return 0;

cleanup_cache:
       kmem_cache_destroy(maple_queue_cache);

cleanup_bothirqs:
       free_irq(HW_EVENT_VSYNC, 0);

cleanup_irq:
       free_irq(HW_EVENT_MAPLE_DMA, 0);

cleanup_dma:
       free_pages((unsigned long) maple_sendbuf, MAPLE_DMA_PAGES);

cleanup_basic:
       driver_unregister(&maple_dummy_driver.drv);

cleanup_bus:
       bus_unregister(&maple_bus_type);

cleanup_device:
       device_unregister(&maple_bus);

cleanup:
       printk(KERN_INFO "Maple bus registration failed\n");
       return retval;
}
subsys_initcall(maple_bus_init);