Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
[linux-3.10.git] / drivers / sh / maple / maple.c
index 7e1257a..cab1ab7 100644 (file)
@@ -1,16 +1,10 @@
 /*
  * Core maple bus functionality
  *
- *  Copyright (C) 2007, 2008 Adrian McMenamin
+ *  Copyright (C) 2007 - 2009 Adrian McMenamin
  *  Copyright (C) 2001 - 2008 Paul Mundt
- *
- * Based on 2.4 code by:
- *
- *  Copyright (C) 2000-2001 YAEGASHI Takeshi
+ *  Copyright (C) 2000 - 2001 YAEGASHI Takeshi
  *  Copyright (C) 2001 M. R. Brown
- *  Copyright (C) 2001 Paul Mundt
- *
- * and others.
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
@@ -32,7 +26,7 @@
 #include <mach/dma.h>
 #include <mach/sysasic.h>
 
-MODULE_AUTHOR("Yaegashi Takeshi, Paul Mundt, M. R. Brown, Adrian McMenamin");
+MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
 MODULE_DESCRIPTION("Maple bus driver for Dreamcast");
 MODULE_LICENSE("GPL v2");
 MODULE_SUPPORTED_DEVICE("{{SEGA, Dreamcast/Maple}}");
@@ -49,7 +43,7 @@ static LIST_HEAD(maple_sentq);
 /* mutex to protect queue of waiting packets */
 static DEFINE_MUTEX(maple_wlist_lock);
 
-static struct maple_driver maple_dummy_driver;
+static struct maple_driver maple_unsupported_device;
 static struct device maple_bus;
 static int subdevice_map[MAPLE_PORTS];
 static unsigned long *maple_sendbuf, *maple_sendptr, *maple_lastptr;
@@ -62,8 +56,9 @@ struct maple_device_specify {
        int unit;
 };
 
-static bool checked[4];
-static struct maple_device *baseunits[4];
+static bool checked[MAPLE_PORTS];
+static bool empty[MAPLE_PORTS];
+static struct maple_device *baseunits[MAPLE_PORTS];
 
 /**
  * maple_driver_register - register a maple driver
@@ -97,12 +92,20 @@ void maple_driver_unregister(struct maple_driver *drv)
 EXPORT_SYMBOL_GPL(maple_driver_unregister);
 
 /* set hardware registers to enable next round of dma */
-static void maplebus_dma_reset(void)
+static void maple_dma_reset(void)
 {
        ctrl_outl(MAPLE_MAGIC, MAPLE_RESET);
        /* set trig type to 0 for software trigger, 1 for hardware (VBLANK) */
        ctrl_outl(1, MAPLE_TRIGTYPE);
-       ctrl_outl(MAPLE_2MBPS | MAPLE_TIMEOUT(50000), MAPLE_SPEED);
+       /*
+       * Maple system register
+       * bits 31 - 16  timeout in units of 20nsec
+       * bit 12        hard trigger - set 0 to keep responding to VBLANK
+       * bits 9 - 8    set 00 for 2 Mbps, 01 for 1 Mbps
+       * bits 3 - 0    delay (in 1.3ms) between VBLANK and start of DMA
+       * max delay is 11
+       */
+       ctrl_outl(MAPLE_2MBPS | MAPLE_TIMEOUT(0xFFFF), MAPLE_SPEED);
        ctrl_outl(PHYSADDR(maple_sendbuf), MAPLE_DMAADDR);
        ctrl_outl(1, MAPLE_ENABLE);
 }
@@ -134,21 +137,16 @@ static void maple_release_device(struct device *dev)
 {
        struct maple_device *mdev;
        struct mapleq *mq;
-       if (!dev)
-               return;
+
        mdev = to_maple_dev(dev);
        mq = mdev->mq;
-       if (mq) {
-               if (mq->recvbufdcsp)
-                       kmem_cache_free(maple_queue_cache, mq->recvbufdcsp);
-               kfree(mq);
-               mq = NULL;
-       }
+       kmem_cache_free(maple_queue_cache, mq->recvbuf);
+       kfree(mq);
        kfree(mdev);
 }
 
 /**
- * maple_add_packet - add a single instruction to the queue
+ * maple_add_packet - add a single instruction to the maple bus queue
  * @mdev: maple device
  * @function: function on device being queried
  * @command: maple command to add
@@ -158,68 +156,12 @@ static void maple_release_device(struct device *dev)
 int maple_add_packet(struct maple_device *mdev, u32 function, u32 command,
        size_t length, void *data)
 {
-       int locking, ret = 0;
+       int ret = 0;
        void *sendbuf = NULL;
 
-       mutex_lock(&maple_wlist_lock);
-       /* bounce if device already locked */
-       locking = mutex_is_locked(&mdev->mq->mutex);
-       if (locking) {
-               ret = -EBUSY;
-               goto out;
-       }
-
-       mutex_lock(&mdev->mq->mutex);
-
        if (length) {
-               sendbuf = kmalloc(length * 4, GFP_KERNEL);
+               sendbuf = kzalloc(length * 4, GFP_KERNEL);
                if (!sendbuf) {
-                       mutex_unlock(&mdev->mq->mutex);
-                       ret = -ENOMEM;
-                       goto out;
-               }
-               ((__be32 *)sendbuf)[0] = cpu_to_be32(function);
-       }
-
-       mdev->mq->command = command;
-       mdev->mq->length = length;
-       if (length > 1)
-               memcpy(sendbuf + 4, data, (length - 1) * 4);
-       mdev->mq->sendbuf = sendbuf;
-
-       list_add(&mdev->mq->list, &maple_waitq);
-out:
-       mutex_unlock(&maple_wlist_lock);
-       return ret;
-}
-EXPORT_SYMBOL_GPL(maple_add_packet);
-
-/**
- * maple_add_packet_sleeps - add a single instruction to the queue
- * @mdev: maple device
- * @function: function on device being queried
- * @command: maple command to add
- * @length: length of command string (in 32 bit words)
- * @data: remainder of command string
- *
- * Same as maple_add_packet(), but waits for the lock to become free.
- */
-int maple_add_packet_sleeps(struct maple_device *mdev, u32 function,
-       u32 command, size_t length, void *data)
-{
-       int locking, ret = 0;
-       void *sendbuf = NULL;
-
-       locking = mutex_lock_interruptible(&mdev->mq->mutex);
-       if (locking) {
-               ret = -EIO;
-               goto out;
-       }
-
-       if (length) {
-               sendbuf = kmalloc(length * 4, GFP_KERNEL);
-               if (!sendbuf) {
-                       mutex_unlock(&mdev->mq->mutex);
                        ret = -ENOMEM;
                        goto out;
                }
@@ -233,38 +175,35 @@ int maple_add_packet_sleeps(struct maple_device *mdev, u32 function,
        mdev->mq->sendbuf = sendbuf;
 
        mutex_lock(&maple_wlist_lock);
-       list_add(&mdev->mq->list, &maple_waitq);
+       list_add_tail(&mdev->mq->list, &maple_waitq);
        mutex_unlock(&maple_wlist_lock);
 out:
        return ret;
 }
-EXPORT_SYMBOL_GPL(maple_add_packet_sleeps);
+EXPORT_SYMBOL_GPL(maple_add_packet);
 
 static struct mapleq *maple_allocq(struct maple_device *mdev)
 {
        struct mapleq *mq;
 
-       mq = kmalloc(sizeof(*mq), GFP_KERNEL);
+       mq = kzalloc(sizeof(*mq), GFP_KERNEL);
        if (!mq)
                goto failed_nomem;
 
+       INIT_LIST_HEAD(&mq->list);
        mq->dev = mdev;
-       mq->recvbufdcsp = kmem_cache_zalloc(maple_queue_cache, GFP_KERNEL);
-       mq->recvbuf = (void *) P2SEGADDR(mq->recvbufdcsp);
+       mq->recvbuf = kmem_cache_zalloc(maple_queue_cache, GFP_KERNEL);
        if (!mq->recvbuf)
                goto failed_p2;
-       /*
-        * most devices do not need the mutex - but
-        * anything that injects block reads or writes
-        * will rely on it
-        */
-       mutex_init(&mq->mutex);
+       mq->recvbuf->buf = &((mq->recvbuf->bufx)[0]);
 
        return mq;
 
 failed_p2:
        kfree(mq);
 failed_nomem:
+       dev_err(&mdev->dev, "could not allocate memory for device (%d, %d)\n",
+               mdev->port, mdev->unit);
        return NULL;
 }
 
@@ -272,12 +211,16 @@ static struct maple_device *maple_alloc_dev(int port, int unit)
 {
        struct maple_device *mdev;
 
+       /* zero this out to avoid kobj subsystem
+       * thinking it has already been registered */
+
        mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
        if (!mdev)
                return NULL;
 
        mdev->port = port;
        mdev->unit = unit;
+
        mdev->mq = maple_allocq(mdev);
 
        if (!mdev->mq) {
@@ -286,19 +229,14 @@ static struct maple_device *maple_alloc_dev(int port, int unit)
        }
        mdev->dev.bus = &maple_bus_type;
        mdev->dev.parent = &maple_bus;
+       init_waitqueue_head(&mdev->maple_wait);
        return mdev;
 }
 
 static void maple_free_dev(struct maple_device *mdev)
 {
-       if (!mdev)
-               return;
-       if (mdev->mq) {
-               if (mdev->mq->recvbufdcsp)
-                       kmem_cache_free(maple_queue_cache,
-                               mdev->mq->recvbufdcsp);
-               kfree(mdev->mq);
-       }
+       kmem_cache_free(maple_queue_cache, mdev->mq->recvbuf);
+       kfree(mdev->mq);
        kfree(mdev);
 }
 
@@ -320,7 +258,7 @@ static void maple_build_block(struct mapleq *mq)
        maple_lastptr = maple_sendptr;
 
        *maple_sendptr++ = (port << 16) | len | 0x80000000;
-       *maple_sendptr++ = PHYSADDR(mq->recvbuf);
+       *maple_sendptr++ = PHYSADDR(mq->recvbuf->buf);
        *maple_sendptr++ =
            mq->command | (to << 8) | (from << 16) | (len << 24);
        while (len-- > 0)
@@ -333,20 +271,28 @@ static void maple_send(void)
        int i, maple_packets = 0;
        struct mapleq *mq, *nmq;
 
-       if (!list_empty(&maple_sentq))
+       if (!maple_dma_done())
                return;
+
+       /* disable DMA */
+       ctrl_outl(0, MAPLE_ENABLE);
+
+       if (!list_empty(&maple_sentq))
+               goto finish;
+
        mutex_lock(&maple_wlist_lock);
-       if (list_empty(&maple_waitq) || !maple_dma_done()) {
+       if (list_empty(&maple_waitq)) {
                mutex_unlock(&maple_wlist_lock);
-               return;
+               goto finish;
        }
-       mutex_unlock(&maple_wlist_lock);
+
        maple_lastptr = maple_sendbuf;
        maple_sendptr = maple_sendbuf;
-       mutex_lock(&maple_wlist_lock);
+
        list_for_each_entry_safe(mq, nmq, &maple_waitq, list) {
                maple_build_block(mq);
-               list_move(&mq->list, &maple_sentq);
+               list_del_init(&mq->list);
+               list_add_tail(&mq->list, &maple_sentq);
                if (maple_packets++ > MAPLE_MAXPACKETS)
                        break;
        }
@@ -356,10 +302,13 @@ static void maple_send(void)
                        dma_cache_sync(0, maple_sendbuf + i * PAGE_SIZE,
                                       PAGE_SIZE, DMA_BIDIRECTIONAL);
        }
+
+finish:
+       maple_dma_reset();
 }
 
 /* check if there is a driver registered likely to match this device */
-static int check_matching_maple_driver(struct device_driver *driver,
+static int maple_check_matching_driver(struct device_driver *driver,
                                        void *devptr)
 {
        struct maple_driver *maple_drv;
@@ -374,10 +323,7 @@ static int check_matching_maple_driver(struct device_driver *driver,
 
 static void maple_detach_driver(struct maple_device *mdev)
 {
-       if (!mdev)
-               return;
        device_unregister(&mdev->dev);
-       mdev = NULL;
 }
 
 /* process initial MAPLE_COMMAND_DEVINFO for each device or port */
@@ -385,9 +331,9 @@ static void maple_attach_driver(struct maple_device *mdev)
 {
        char *p, *recvbuf;
        unsigned long function;
-       int matched, retval;
+       int matched, error;
 
-       recvbuf = mdev->mq->recvbuf;
+       recvbuf = mdev->mq->recvbuf->buf;
        /* copy the data as individual elements in
        * case of memory optimisation */
        memcpy(&mdev->devinfo.function, recvbuf + 4, 4);
@@ -395,7 +341,6 @@ static void maple_attach_driver(struct maple_device *mdev)
        memcpy(&mdev->devinfo.area_code, recvbuf + 20, 1);
        memcpy(&mdev->devinfo.connector_direction, recvbuf + 21, 1);
        memcpy(&mdev->devinfo.product_name[0], recvbuf + 22, 30);
-       memcpy(&mdev->devinfo.product_licence[0], recvbuf + 52, 60);
        memcpy(&mdev->devinfo.standby_power, recvbuf + 112, 2);
        memcpy(&mdev->devinfo.max_power, recvbuf + 114, 2);
        memcpy(mdev->product_name, mdev->devinfo.product_name, 30);
@@ -414,43 +359,39 @@ static void maple_attach_driver(struct maple_device *mdev)
                else
                        break;
 
-       printk(KERN_INFO "Maple device detected: %s\n",
-               mdev->product_name);
-       printk(KERN_INFO "Maple device: %s\n", mdev->product_licence);
-
        function = be32_to_cpu(mdev->devinfo.function);
 
+       dev_info(&mdev->dev, "detected %s: function 0x%lX: at (%d, %d)\n",
+               mdev->product_name, function, mdev->port, mdev->unit);
+
        if (function > 0x200) {
                /* Do this silently - as not a real device */
                function = 0;
-               mdev->driver = &maple_dummy_driver;
+               mdev->driver = &maple_unsupported_device;
                dev_set_name(&mdev->dev, "%d:0.port", mdev->port);
        } else {
-               printk(KERN_INFO
-                       "Maple bus at (%d, %d): Function 0x%lX\n",
-                       mdev->port, mdev->unit, function);
-
                matched =
                        bus_for_each_drv(&maple_bus_type, NULL, mdev,
-                               check_matching_maple_driver);
+                               maple_check_matching_driver);
 
                if (matched == 0) {
                        /* Driver does not exist yet */
-                       printk(KERN_INFO
-                               "No maple driver found.\n");
-                       mdev->driver = &maple_dummy_driver;
+                       dev_info(&mdev->dev, "no driver found\n");
+                       mdev->driver = &maple_unsupported_device;
                }
                dev_set_name(&mdev->dev, "%d:0%d.%lX", mdev->port,
                             mdev->unit, function);
        }
+
        mdev->function = function;
        mdev->dev.release = &maple_release_device;
-       retval = device_register(&mdev->dev);
-       if (retval) {
-               printk(KERN_INFO
-               "Maple bus: Attempt to register device"
-               " (%x, %x) failed.\n",
-               mdev->port, mdev->unit);
+
+       atomic_set(&mdev->busy, 0);
+       error = device_register(&mdev->dev);
+       if (error) {
+               dev_warn(&mdev->dev, "could not register device at"
+                       " (%d, %d), with error 0x%X\n", mdev->unit,
+                       mdev->port, error);
                maple_free_dev(mdev);
                mdev = NULL;
                return;
@@ -462,7 +403,7 @@ static void maple_attach_driver(struct maple_device *mdev)
  * port and unit then return 1 - allows identification
  * of which devices need to be attached or detached
  */
-static int detach_maple_device(struct device *device, void *portptr)
+static int check_maple_device(struct device *device, void *portptr)
 {
        struct maple_device_specify *ds;
        struct maple_device *mdev;
@@ -477,21 +418,25 @@ static int detach_maple_device(struct device *device, void *portptr)
 static int setup_maple_commands(struct device *device, void *ignored)
 {
        int add;
-       struct maple_device *maple_dev = to_maple_dev(device);
-
-       if ((maple_dev->interval > 0)
-           && time_after(jiffies, maple_dev->when)) {
-               /* bounce if we cannot lock */
-               add = maple_add_packet(maple_dev,
-                       be32_to_cpu(maple_dev->devinfo.function),
+       struct maple_device *mdev = to_maple_dev(device);
+       if (mdev->interval > 0 && atomic_read(&mdev->busy) == 0 &&
+               time_after(jiffies, mdev->when)) {
+               /* bounce if we cannot add */
+               add = maple_add_packet(mdev,
+                       be32_to_cpu(mdev->devinfo.function),
                        MAPLE_COMMAND_GETCOND, 1, NULL);
                if (!add)
-                       maple_dev->when = jiffies + maple_dev->interval;
+                       mdev->when = jiffies + mdev->interval;
        } else {
                if (time_after(jiffies, maple_pnp_time))
-                       /* This will also bounce */
-                       maple_add_packet(maple_dev, 0,
-                               MAPLE_COMMAND_DEVINFO, 0, NULL);
+                       /* Ensure we don't have block reads and devinfo
+                       * calls interfering with one another - so flag the
+                       * device as busy */
+                       if (atomic_read(&mdev->busy) == 0) {
+                               atomic_set(&mdev->busy, 1);
+                               maple_add_packet(mdev, 0,
+                                       MAPLE_COMMAND_DEVINFO, 0, NULL);
+                       }
        }
        return 0;
 }
@@ -499,29 +444,50 @@ static int setup_maple_commands(struct device *device, void *ignored)
 /* VBLANK bottom half - implemented via workqueue */
 static void maple_vblank_handler(struct work_struct *work)
 {
-       if (!list_empty(&maple_sentq) || !maple_dma_done())
+       int x, locking;
+       struct maple_device *mdev;
+
+       if (!maple_dma_done())
                return;
 
        ctrl_outl(0, MAPLE_ENABLE);
 
+       if (!list_empty(&maple_sentq))
+               goto finish;
+
+       /*
+       * Set up essential commands - to fetch data and
+       * check devices are still present
+       */
        bus_for_each_dev(&maple_bus_type, NULL, NULL,
-                        setup_maple_commands);
+               setup_maple_commands);
+
+       if (time_after(jiffies, maple_pnp_time)) {
+               /*
+               * Scan the empty ports - bus is flakey and may have
+               * mis-reported emptyness
+               */
+               for (x = 0; x < MAPLE_PORTS; x++) {
+                       if (checked[x] && empty[x]) {
+                               mdev = baseunits[x];
+                               if (!mdev)
+                                       break;
+                               atomic_set(&mdev->busy, 1);
+                               locking = maple_add_packet(mdev, 0,
+                                       MAPLE_COMMAND_DEVINFO, 0, NULL);
+                               if (!locking)
+                                       break;
+                               }
+                       }
 
-       if (time_after(jiffies, maple_pnp_time))
                maple_pnp_time = jiffies + MAPLE_PNP_INTERVAL;
-
-       mutex_lock(&maple_wlist_lock);
-       if (!list_empty(&maple_waitq) && list_empty(&maple_sentq)) {
-               mutex_unlock(&maple_wlist_lock);
-               maple_send();
-       } else {
-               mutex_unlock(&maple_wlist_lock);
        }
 
-       maplebus_dma_reset();
+finish:
+       maple_send();
 }
 
-/* handle devices added via hotplugs - placing them on queue for DEVINFO*/
+/* 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;
@@ -533,7 +499,7 @@ static void maple_map_subunits(struct maple_device *mdev, int submask)
                ds.unit = k + 1;
                retval =
                    bus_for_each_dev(&maple_bus_type, NULL, &ds,
-                                    detach_maple_device);
+                                    check_maple_device);
                if (retval) {
                        submask = submask >> 1;
                        continue;
@@ -543,6 +509,7 @@ static void maple_map_subunits(struct maple_device *mdev, int submask)
                        mdev_add = maple_alloc_dev(mdev->port, k + 1);
                        if (!mdev_add)
                                return;
+                       atomic_set(&mdev_add->busy, 1);
                        maple_add_packet(mdev_add, 0, MAPLE_COMMAND_DEVINFO,
                                0, NULL);
                        /* mark that we are checking sub devices */
@@ -564,27 +531,45 @@ static void maple_clean_submap(struct maple_device *mdev)
 }
 
 /* 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);
+static void maple_response_none(struct maple_device *mdev)
+{
+       maple_clean_submap(mdev);
+
+       if (likely(mdev->unit != 0)) {
+               /*
+               * Block devices play up
+               * and give the impression they have
+               * been removed even when still in place or
+               * trip the mtd layer when they have
+               * really gone - this code traps that eventuality
+               * and ensures we aren't overloaded with useless
+               * error messages
+               */
+               if (mdev->can_unload) {
+                       if (!mdev->can_unload(mdev)) {
+                               atomic_set(&mdev->busy, 2);
+                               wake_up(&mdev->maple_wait);
+                               return;
+                       }
+               }
+
+               dev_info(&mdev->dev, "detaching device at (%d, %d)\n",
+                       mdev->port, mdev->unit);
                maple_detach_driver(mdev);
                return;
-       }
-       if (!started || !fullscan) {
-               if (checked[mdev->port] == false) {
-                       checked[mdev->port] = true;
-                       printk(KERN_INFO "No maple devices attached"
-                               " to port %d\n", mdev->port);
+       } else {
+               if (!started || !fullscan) {
+                       if (checked[mdev->port] == false) {
+                               checked[mdev->port] = true;
+                               empty[mdev->port] = true;
+                               dev_info(&mdev->dev, "no devices"
+                                       " to port %d\n", mdev->port);
+                       }
+                       return;
                }
-               return;
        }
-       maple_clean_submap(mdev);
+       /* Some hardware devices generate false detach messages on unit 0 */
+       atomic_set(&mdev->busy, 0);
 }
 
 /* preprocess hotplugs or scans */
@@ -599,8 +584,11 @@ static void maple_response_devinfo(struct maple_device *mdev,
                } else {
                        if (mdev->unit != 0)
                                maple_attach_driver(mdev);
+                       if (mdev->unit == 0) {
+                               empty[mdev->port] = false;
+                               maple_attach_driver(mdev);
+                       }
                }
-               return;
        }
        if (mdev->unit == 0) {
                submask = recvbuf[2] & 0x1F;
@@ -611,6 +599,17 @@ static void maple_response_devinfo(struct maple_device *mdev,
        }
 }
 
+static void maple_response_fileerr(struct maple_device *mdev, void *recvbuf)
+{
+       if (mdev->fileerr_handler) {
+               mdev->fileerr_handler(mdev, recvbuf);
+               return;
+       } else
+               dev_warn(&mdev->dev, "device at (%d, %d) reports"
+                       "file error 0x%X\n", mdev->port, mdev->unit,
+                       ((int *)recvbuf)[1]);
+}
+
 static void maple_port_rescan(void)
 {
        int i;
@@ -621,12 +620,6 @@ static void maple_port_rescan(void)
                if (checked[i] == false) {
                        fullscan = 0;
                        mdev = baseunits[i];
-                       /*
-                        *  test lock in case scan has failed
-                        *  but device is still locked
-                        */
-                       if (mutex_is_locked(&mdev->mq->mutex))
-                               mutex_unlock(&mdev->mq->mutex);
                        maple_add_packet(mdev, 0, MAPLE_COMMAND_DEVINFO,
                                0, NULL);
                }
@@ -637,7 +630,7 @@ static void maple_port_rescan(void)
 static void maple_dma_handler(struct work_struct *work)
 {
        struct mapleq *mq, *nmq;
-       struct maple_device *dev;
+       struct maple_device *mdev;
        char *recvbuf;
        enum maple_code code;
 
@@ -646,43 +639,56 @@ static void maple_dma_handler(struct work_struct *work)
        ctrl_outl(0, MAPLE_ENABLE);
        if (!list_empty(&maple_sentq)) {
                list_for_each_entry_safe(mq, nmq, &maple_sentq, list) {
-                       recvbuf = mq->recvbuf;
+                       mdev = mq->dev;
+                       recvbuf = mq->recvbuf->buf;
+                       dma_cache_sync(&mdev->dev, recvbuf, 0x400,
+                               DMA_FROM_DEVICE);
                        code = recvbuf[0];
-                       dev = mq->dev;
                        kfree(mq->sendbuf);
-                       mutex_unlock(&mq->mutex);
                        list_del_init(&mq->list);
-
                        switch (code) {
                        case MAPLE_RESPONSE_NONE:
-                               maple_response_none(dev, mq);
+                               maple_response_none(mdev);
                                break;
 
                        case MAPLE_RESPONSE_DEVINFO:
-                               maple_response_devinfo(dev, recvbuf);
+                               maple_response_devinfo(mdev, recvbuf);
+                               atomic_set(&mdev->busy, 0);
                                break;
 
                        case MAPLE_RESPONSE_DATATRF:
-                               if (dev->callback)
-                                       dev->callback(mq);
+                               if (mdev->callback)
+                                       mdev->callback(mq);
+                               atomic_set(&mdev->busy, 0);
+                               wake_up(&mdev->maple_wait);
                                break;
 
                        case MAPLE_RESPONSE_FILEERR:
+                               maple_response_fileerr(mdev, recvbuf);
+                               atomic_set(&mdev->busy, 0);
+                               wake_up(&mdev->maple_wait);
+                               break;
+
                        case MAPLE_RESPONSE_AGAIN:
                        case MAPLE_RESPONSE_BADCMD:
                        case MAPLE_RESPONSE_BADFUNC:
-                               printk(KERN_DEBUG
-                                      "Maple non-fatal error 0x%X\n",
-                                      code);
+                               dev_warn(&mdev->dev, "non-fatal error"
+                                       " 0x%X at (%d, %d)\n", code,
+                                       mdev->port, mdev->unit);
+                               atomic_set(&mdev->busy, 0);
                                break;
 
                        case MAPLE_RESPONSE_ALLINFO:
-                               printk(KERN_DEBUG
-                                      "Maple - extended device information"
-                                       " not supported\n");
+                               dev_notice(&mdev->dev, "extended"
+                               " device information request for (%d, %d)"
+                               " but call is not supported\n", mdev->port,
+                               mdev->unit);
+                               atomic_set(&mdev->busy, 0);
                                break;
 
                        case MAPLE_RESPONSE_OK:
+                               atomic_set(&mdev->busy, 0);
+                               wake_up(&mdev->maple_wait);
                                break;
 
                        default:
@@ -699,20 +705,19 @@ static void maple_dma_handler(struct work_struct *work)
                if (!fullscan)
                        maple_port_rescan();
                /* mark that we have been through the first scan */
-               if (started == 0)
-                       started = 1;
+               started = 1;
        }
-       maplebus_dma_reset();
+       maple_send();
 }
 
-static irqreturn_t maplebus_dma_interrupt(int irq, void *dev_id)
+static irqreturn_t maple_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)
+static irqreturn_t maple_vblank_interrupt(int irq, void *dev_id)
 {
        schedule_work(&maple_vblank_process);
        return IRQ_HANDLED;
@@ -720,14 +725,14 @@ static irqreturn_t maplebus_vblank_interrupt(int irq, void *dev_id)
 
 static int maple_set_dma_interrupt_handler(void)
 {
-       return request_irq(HW_EVENT_MAPLE_DMA, maplebus_dma_interrupt,
-               IRQF_SHARED, "maple bus DMA", &maple_dummy_driver);
+       return request_irq(HW_EVENT_MAPLE_DMA, maple_dma_interrupt,
+               IRQF_SHARED, "maple bus DMA", &maple_unsupported_device);
 }
 
 static int maple_set_vblank_interrupt_handler(void)
 {
-       return request_irq(HW_EVENT_VSYNC, maplebus_vblank_interrupt,
-               IRQF_SHARED, "maple bus VBLANK", &maple_dummy_driver);
+       return request_irq(HW_EVENT_VSYNC, maple_vblank_interrupt,
+               IRQF_SHARED, "maple bus VBLANK", &maple_unsupported_device);
 }
 
 static int maple_get_dma_buffer(void)
@@ -740,7 +745,7 @@ static int maple_get_dma_buffer(void)
        return 0;
 }
 
-static int match_maple_bus_driver(struct device *devptr,
+static int maple_match_bus_driver(struct device *devptr,
                                  struct device_driver *drvptr)
 {
        struct maple_driver *maple_drv = to_maple_driver(drvptr);
@@ -765,16 +770,18 @@ static void maple_bus_release(struct device *dev)
 {
 }
 
-static struct maple_driver maple_dummy_driver = {
+static struct maple_driver maple_unsupported_device = {
        .drv = {
-               .name = "maple_dummy_driver",
+               .name = "maple_unsupported_device",
                .bus = &maple_bus_type,
        },
 };
-
+/**
+ * maple_bus_type - core maple bus structure
+ */
 struct bus_type maple_bus_type = {
        .name = "maple",
-       .match = match_maple_bus_driver,
+       .match = maple_match_bus_driver,
        .uevent = maple_bus_uevent,
 };
 EXPORT_SYMBOL_GPL(maple_bus_type);
@@ -788,7 +795,8 @@ static int __init maple_bus_init(void)
 {
        int retval, i;
        struct maple_device *mdev[MAPLE_PORTS];
-       ctrl_outl(0, MAPLE_STATE);
+
+       ctrl_outl(0, MAPLE_ENABLE);
 
        retval = device_register(&maple_bus);
        if (retval)
@@ -798,36 +806,33 @@ static int __init maple_bus_init(void)
        if (retval)
                goto cleanup_device;
 
-       retval = driver_register(&maple_dummy_driver.drv);
+       retval = driver_register(&maple_unsupported_device.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");
+               dev_err(&maple_bus, "failed to allocate 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");
+               dev_err(&maple_bus, "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");
+               dev_err(&maple_bus, "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);
+       maple_queue_cache = KMEM_CACHE(maple_buffer, SLAB_HWCACHE_ALIGN);
 
        if (!maple_queue_cache)
                goto cleanup_bothirqs;
@@ -838,23 +843,23 @@ static int __init maple_bus_init(void)
        /* setup maple ports */
        for (i = 0; i < MAPLE_PORTS; i++) {
                checked[i] = false;
+               empty[i] = false;
                mdev[i] = maple_alloc_dev(i, 0);
-               baseunits[i] = mdev[i];
                if (!mdev[i]) {
                        while (i-- > 0)
                                maple_free_dev(mdev[i]);
                        goto cleanup_cache;
                }
+               baseunits[i] = mdev[i];
+               atomic_set(&mdev[i]->busy, 1);
                maple_add_packet(mdev[i], 0, MAPLE_COMMAND_DEVINFO, 0, NULL);
                subdevice_map[i] = 0;
        }
 
-       /* setup maplebus hardware */
-       maplebus_dma_reset();
-       /* initial detection */
+       maple_pnp_time = jiffies + HZ;
+       /* prepare initial queue */
        maple_send();
-       maple_pnp_time = jiffies;
-       printk(KERN_INFO "Maple bus core now registered.\n");
+       dev_info(&maple_bus, "bus core now registered\n");
 
        return 0;
 
@@ -871,7 +876,7 @@ cleanup_dma:
        free_pages((unsigned long) maple_sendbuf, MAPLE_DMA_PAGES);
 
 cleanup_basic:
-       driver_unregister(&maple_dummy_driver.drv);
+       driver_unregister(&maple_unsupported_device.drv);
 
 cleanup_bus:
        bus_unregister(&maple_bus_type);
@@ -880,7 +885,7 @@ cleanup_device:
        device_unregister(&maple_bus);
 
 cleanup:
-       printk(KERN_INFO "Maple bus registration failed\n");
+       printk(KERN_ERR "Maple bus registration failed\n");
        return retval;
 }
 /* Push init to later to ensure hardware gets detected */