sh/maple: clean maple bus code
[pandora-kernel.git] / drivers / sh / maple / maple.c
index 617efb1..be97789 100644 (file)
 #include <linux/slab.h>
 #include <linux/maple.h>
 #include <linux/dma-mapping.h>
+#include <linux/delay.h>
 #include <asm/cacheflush.h>
 #include <asm/dma.h>
 #include <asm/io.h>
-#include <asm/mach/dma.h>
-#include <asm/mach/sysasic.h>
-#include <asm/mach/maple.h>
-#include <linux/delay.h>
+#include <mach/dma.h>
+#include <mach/sysasic.h>
 
 MODULE_AUTHOR("Yaegshi Takeshi, Paul Mundt, M.R. Brown, Adrian McMenamin");
 MODULE_DESCRIPTION("Maple bus driver for Dreamcast");
@@ -46,14 +45,15 @@ static DECLARE_WORK(maple_vblank_process, maple_vblank_handler);
 static LIST_HEAD(maple_waitq);
 static LIST_HEAD(maple_sentq);
 
-static DEFINE_MUTEX(maple_list_lock);
+/* mutex to protect queue of waiting packets */
+static DEFINE_MUTEX(maple_wlist_lock);
 
 static struct maple_driver maple_dummy_driver;
 static struct device maple_bus;
 static int subdevice_map[MAPLE_PORTS];
 static unsigned long *maple_sendbuf, *maple_sendptr, *maple_lastptr;
 static unsigned long maple_pnp_time;
-static int started, scanning, liststatus, fullscan;
+static int started, scanning, fullscan;
 static struct kmem_cache *maple_queue_cache;
 
 struct maple_device_specify {
@@ -129,35 +129,124 @@ static void maple_release_device(struct device *dev)
        kfree(mdev);
 }
 
-/**
+/*
  * maple_add_packet - add a single instruction to the queue
- * @mq: instruction to add to waiting 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
  */
-void maple_add_packet(struct mapleq *mq)
+int maple_add_packet(struct maple_device *mdev, u32 function, u32 command,
+       size_t length, void *data)
 {
-       mutex_lock(&maple_list_lock);
-       list_add(&mq->list, &maple_waitq);
-       mutex_unlock(&maple_list_lock);
+       int locking, 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);
+               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
+ *  - waits for lock to be free
+ * @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
+ */
+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;
+               }
+               ((__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;
+
+       mutex_lock(&maple_wlist_lock);
+       list_add(&mdev->mq->list, &maple_waitq);
+       mutex_unlock(&maple_wlist_lock);
+out:
+       return ret;
+}
+EXPORT_SYMBOL_GPL(maple_add_packet_sleeps);
+
 static struct mapleq *maple_allocq(struct maple_device *mdev)
 {
        struct mapleq *mq;
 
        mq = kmalloc(sizeof(*mq), GFP_KERNEL);
        if (!mq)
-               return NULL;
+               goto failed_nomem;
 
        mq->dev = mdev;
        mq->recvbufdcsp = kmem_cache_zalloc(maple_queue_cache, GFP_KERNEL);
        mq->recvbuf = (void *) P2SEGADDR(mq->recvbufdcsp);
-       if (!mq->recvbuf) {
-               kfree(mq);
-               return NULL;
-       }
+       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);
 
        return mq;
+
+failed_p2:
+       kfree(mq);
+failed_nomem:
+       return NULL;
 }
 
 static struct maple_device *maple_alloc_dev(int port, int unit)
@@ -178,7 +267,6 @@ static struct maple_device *maple_alloc_dev(int port, int unit)
        }
        mdev->dev.bus = &maple_bus_type;
        mdev->dev.parent = &maple_bus;
-       mdev->function = 0;
        return mdev;
 }
 
@@ -216,7 +304,6 @@ static void maple_build_block(struct mapleq *mq)
        *maple_sendptr++ = PHYSADDR(mq->recvbuf);
        *maple_sendptr++ =
            mq->command | (to << 8) | (from << 16) | (len << 24);
-
        while (len-- > 0)
                *maple_sendptr++ = *lsendbuf++;
 }
@@ -224,22 +311,27 @@ static void maple_build_block(struct mapleq *mq)
 /* build up command queue */
 static void maple_send(void)
 {
-       int i;
-       int maple_packets;
+       int i, maple_packets = 0;
        struct mapleq *mq, *nmq;
 
        if (!list_empty(&maple_sentq))
                return;
-       if (list_empty(&maple_waitq) || !maple_dma_done())
+       mutex_lock(&maple_wlist_lock);
+       if (list_empty(&maple_waitq) || !maple_dma_done()) {
+               mutex_unlock(&maple_wlist_lock);
                return;
-       maple_packets = 0;
-       maple_sendptr = maple_lastptr = maple_sendbuf;
+       }
+       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);
                if (maple_packets++ > MAPLE_MAXPACKETS)
                        break;
        }
+       mutex_unlock(&maple_wlist_lock);
        if (maple_packets > 0) {
                for (i = 0; i < (1 << MAPLE_DMA_PAGES); i++)
                        dma_cache_sync(0, maple_sendbuf + i * PAGE_SIZE,
@@ -247,7 +339,8 @@ static void maple_send(void)
        }
 }
 
-static int attach_matching_maple_driver(struct device_driver *driver,
+/* check if there is a driver registered likely to match this device */
+static int check_matching_maple_driver(struct device_driver *driver,
                                        void *devptr)
 {
        struct maple_driver *maple_drv;
@@ -255,12 +348,8 @@ static int attach_matching_maple_driver(struct device_driver *driver,
 
        mdev = devptr;
        maple_drv = to_maple_driver(driver);
-       if (mdev->devinfo.function & be32_to_cpu(maple_drv->function)) {
-               if (maple_drv->connect(mdev) == 0) {
-                       mdev->driver = maple_drv;
-                       return 1;
-               }
-       }
+       if (mdev->devinfo.function & cpu_to_be32(maple_drv->function))
+               return 1;
        return 0;
 }
 
@@ -268,11 +357,6 @@ static void maple_detach_driver(struct maple_device *mdev)
 {
        if (!mdev)
                return;
-       if (mdev->driver) {
-               if (mdev->driver->disconnect)
-                       mdev->driver->disconnect(mdev);
-       }
-       mdev->driver = NULL;
        device_unregister(&mdev->dev);
        mdev = NULL;
 }
@@ -328,8 +412,8 @@ static void maple_attach_driver(struct maple_device *mdev)
                        mdev->port, mdev->unit, function);
 
                matched =
-                   bus_for_each_drv(&maple_bus_type, NULL, mdev,
-                                    attach_matching_maple_driver);
+                       bus_for_each_drv(&maple_bus_type, NULL, mdev,
+                               check_matching_maple_driver);
 
                if (matched == 0) {
                        /* Driver does not exist yet */
@@ -373,45 +457,48 @@ 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)) {
-               maple_dev->when = jiffies + maple_dev->interval;
-               maple_dev->mq->command = MAPLE_COMMAND_GETCOND;
-               maple_dev->mq->sendbuf = &maple_dev->function;
-               maple_dev->mq->length = 1;
-               maple_add_packet(maple_dev->mq);
-               liststatus++;
+               /* bounce if we cannot lock */
+               add = maple_add_packet(maple_dev,
+                       be32_to_cpu(maple_dev->devinfo.function),
+                       MAPLE_COMMAND_GETCOND, 1, NULL);
+               if (!add)
+                       maple_dev->when = jiffies + maple_dev->interval;
        } else {
-               if (time_after(jiffies, maple_pnp_time)) {
-                       maple_dev->mq->command = MAPLE_COMMAND_DEVINFO;
-                       maple_dev->mq->length = 0;
-                       maple_add_packet(maple_dev->mq);
-                       liststatus++;
-               }
+               if (time_after(jiffies, maple_pnp_time))
+                       /* This will also bounce */
+                       maple_add_packet(maple_dev, 0,
+                               MAPLE_COMMAND_DEVINFO, 0, NULL);
        }
-
        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))
+       if (!list_empty(&maple_sentq) || !maple_dma_done())
                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);
+
+       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();
 }
 
@@ -422,8 +509,8 @@ static void maple_map_subunits(struct maple_device *mdev, int submask)
        struct maple_device *mdev_add;
        struct maple_device_specify ds;
 
+       ds.port = mdev->port;
        for (k = 0; k < 5; k++) {
-               ds.port = mdev->port;
                ds.unit = k + 1;
                retval =
                    bus_for_each_dev(&maple_bus_type, NULL, &ds,
@@ -437,9 +524,9 @@ static void maple_map_subunits(struct maple_device *mdev, int submask)
                        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);
+                       maple_add_packet(mdev_add, 0, MAPLE_COMMAND_DEVINFO,
+                               0, NULL);
+                       /* mark that we are checking sub devices */
                        scanning = 1;
                }
                submask = submask >> 1;
@@ -505,6 +592,28 @@ static void maple_response_devinfo(struct maple_device *mdev,
        }
 }
 
+static void maple_port_rescan(void)
+{
+       int i;
+       struct maple_device *mdev;
+
+       fullscan = 1;
+       for (i = 0; i < MAPLE_PORTS; i++) {
+               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);
+               }
+       }
+}
+
 /* maple dma end bottom half - implemented via workqueue */
 static void maple_dma_handler(struct work_struct *work)
 {
@@ -512,7 +621,6 @@ static void maple_dma_handler(struct work_struct *work)
        struct maple_device *dev;
        char *recvbuf;
        enum maple_code code;
-       int i;
 
        if (!maple_dma_done())
                return;
@@ -522,6 +630,10 @@ static void maple_dma_handler(struct work_struct *work)
                        recvbuf = mq->recvbuf;
                        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);
@@ -558,26 +670,16 @@ static void maple_dma_handler(struct work_struct *work)
                                break;
                        }
                }
-               INIT_LIST_HEAD(&maple_sentq);
+               /* if scanning is 1 then we have subdevices to check */
                if (scanning == 1) {
                        maple_send();
                        scanning = 2;
                } else
                        scanning = 0;
-
-               if (!fullscan) {
-                       fullscan = 1;
-                       for (i = 0; i < MAPLE_PORTS; i++) {
-                               if (checked[i] == false) {
-                                       fullscan = 0;
-                                       dev = baseunits[i];
-                                       dev->mq->command =
-                                               MAPLE_COMMAND_DEVINFO;
-                                       dev->mq->length = 0;
-                                       maple_add_packet(dev->mq);
-                               }
-                       }
-               }
+               /*check if we have actually tested all ports yet */
+               if (!fullscan)
+                       maple_port_rescan();
+               /* mark that we have been through the first scan */
                if (started == 0)
                        started = 1;
        }
@@ -631,7 +733,7 @@ static int match_maple_bus_driver(struct device *devptr,
        if (maple_dev->devinfo.function == 0xFFFFFFFF)
                return 0;
        else if (maple_dev->devinfo.function &
-                be32_to_cpu(maple_drv->function))
+                cpu_to_be32(maple_drv->function))
                return 1;
        return 0;
 }
@@ -713,6 +815,9 @@ static int __init maple_bus_init(void)
        if (!maple_queue_cache)
                goto cleanup_bothirqs;
 
+       INIT_LIST_HEAD(&maple_waitq);
+       INIT_LIST_HEAD(&maple_sentq);
+
        /* setup maple ports */
        for (i = 0; i < MAPLE_PORTS; i++) {
                checked[i] = false;
@@ -723,9 +828,7 @@ static int __init maple_bus_init(void)
                                maple_free_dev(mdev[i]);
                        goto cleanup_cache;
                }
-               mdev[i]->mq->command = MAPLE_COMMAND_DEVINFO;
-               mdev[i]->mq->length = 0;
-               maple_add_packet(mdev[i]->mq);
+               maple_add_packet(mdev[i], 0, MAPLE_COMMAND_DEVINFO, 0, NULL);
                subdevice_map[i] = 0;
        }