powerpc/macio: Rework hotplug media bay support

The hotplug mediabay has tendrils deep into drivers/ide code
which makes a libata port reather difficult. In addition it's
ugly and could be done better.

This reworks the interface between the mediabay and the rest
of the world so that:

   - Any macio_driver can now have a mediabay_event callback
which will be called when that driver sits on a mediabay and
it's been either plugged or unplugged. The device type is
passed as an argument. We can now move all the IDE cruft
into the IDE driver itself

   - A check_media_bay() function can be used to take a peek
at the type of device currently in the bay if any, a cleaner
variant of the previous function with the same name.

   - A pair of lock/unlock functions are exposed to allow the
IDE driver to block the hotplug callbacks during the initial
setup and probing of the bay in order to avoid nasty race
conditions.

   - The mediabay code no longer needs to spin on the status
register of the IDE interface when it detects an IDE device,
this is done just fine by the IDE code itself

Overall, less code, simpler, and allows for another driver
than our old drivers/ide based one.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 122 insertions, 206 deletions

diff --git a/drivers/macintosh/mediabay.c b/drivers/macintosh/mediabay.c
index 029ad8ce8a7e..08002b88f342 100644
--- a/drivers/macintosh/mediabay.c
+++ b/drivers/macintosh/mediabay.c
@@ -33,15 +33,6 @@
 #include <linux/adb.h>
 #include <linux/pmu.h>
 
-
-#define MB_DEBUG
-
-#ifdef MB_DEBUG
-#define MBDBG(fmt, arg...)      printk(KERN_INFO fmt , ## arg)
-#else
-#define MBDBG(fmt, arg...)      do { } while (0)
-#endif
-
 #define MB_FCR32(bay, r)        ((bay)->base + ((r) >> 2))
 #define MB_FCR8(bay, r)         (((volatile u8 __iomem *)((bay)->base)) + (r))
 
@@ -76,28 +67,14 @@ struct media_bay_info {
         int                             index;
         int                             cached_gpio;
         int                             sleeping;
+        int                             user_lock;
         struct mutex                    lock;
-#ifdef CONFIG_BLK_DEV_IDE_PMAC
-        ide_hwif_t                      *cd_port;
-        void __iomem                    *cd_base;
-        int                             cd_irq;
-        int                             cd_retry;
-#endif
-#if defined(CONFIG_BLK_DEV_IDE_PMAC)
-        int                             cd_index;
-#endif
 };
 
 #define MAX_BAYS        2
 
 static struct media_bay_info media_bays[MAX_BAYS];
-int media_bay_count = 0;
-
-#ifdef CONFIG_BLK_DEV_IDE_PMAC
-/* check the busy bit in the media-bay ide interface
-   (assumes the media-bay contains an ide device) */
-#define MB_IDE_READY(i) ((readb(media_bays[i].cd_base + 0x70) & 0x80) == 0)
-#endif
+static int media_bay_count = 0;
 
 /*
  * Wait that number of ms between each step in normal polling mode
@@ -130,21 +107,11 @@ int media_bay_count = 0;
 
 /*
  * Wait this many ticks after an IDE device (e.g. CD-ROM) is inserted
- * (or until the device is ready) before waiting for busy bit to disappear
+ * (or until the device is ready) before calling into the driver
  */
 #define MB_IDE_WAIT     1000
 
 /*
- * Timeout waiting for busy bit of an IDE device to go down
- */
-#define MB_IDE_TIMEOUT  5000
-
-/*
- * Max retries of the full power up/down sequence for an IDE device
- */
-#define MAX_CD_RETRIES  3
-
-/*
  * States of a media bay
  */
 enum {
@@ -153,7 +120,6 @@ enum {
         mb_enabling_bay,        /* enable bits set, waiting MB_RESET_DELAY */
         mb_resetting,           /* reset bit unset, waiting MB_SETUP_DELAY */
         mb_ide_resetting,       /* IDE reset bit unser, waiting MB_IDE_WAIT */
-        mb_ide_waiting,         /* Waiting for BUSY bit to go away until MB_IDE_TIMEOUT */
         mb_up,                  /* Media bay full */
         mb_powering_down        /* Powering down (avoid too fast down/up) */
 };
@@ -373,12 +339,12 @@ static inline void set_mb_power(struct media_bay_info* bay, int onoff)
         if (onoff) {
                 bay->ops->power(bay, 1);
                 bay->state = mb_powering_up;
-                MBDBG("mediabay%d: powering up\n", bay->index);
+                pr_debug("mediabay%d: powering up\n", bay->index);
         } else { 
                 /* Make sure everything is powered down & disabled */
                 bay->ops->power(bay, 0);
                 bay->state = mb_powering_down;
-                MBDBG("mediabay%d: powering down\n", bay->index);
+                pr_debug("mediabay%d: powering down\n", bay->index);
         }
         bay->timer = msecs_to_jiffies(MB_POWER_DELAY);
 }
@@ -387,107 +353,118 @@ static void poll_media_bay(struct media_bay_info* bay)
 {
         int id = bay->ops->content(bay);
 
-        if (id == bay->last_value) {
-                if (id != bay->content_id) {
-                        bay->value_count += msecs_to_jiffies(MB_POLL_DELAY);
-                        if (bay->value_count >= msecs_to_jiffies(MB_STABLE_DELAY)) {
-                                /* If the device type changes without going thru
-                                 * "MB_NO", we force a pass by "MB_NO" to make sure
-                                 * things are properly reset
-                                 */
-                                if ((id != MB_NO) && (bay->content_id != MB_NO)) {
-                                        id = MB_NO;
-                                        MBDBG("mediabay%d: forcing MB_NO\n", bay->index);
-                                }
-                                MBDBG("mediabay%d: switching to %d\n", bay->index, id);
-                                set_mb_power(bay, id != MB_NO);
-                                bay->content_id = id;
-                                if (id == MB_NO) {
-#ifdef CONFIG_BLK_DEV_IDE_PMAC
-                                        bay->cd_retry = 0;
-#endif
-                                        printk(KERN_INFO "media bay %d is empty\n", bay->index);
-                                }
-                        }
-                }
-        } else {
+        static char *mb_content_types[] = {
+                "a floppy drive",
+                "a floppy drive",
+                "an unsuported audio device",
+                "an ATA device",
+                "an unsupported PCI device",
+                "an unknown device",
+        };
+
+        if (id != bay->last_value) {
                 bay->last_value = id;
                 bay->value_count = 0;
+                return;
+        }
+        if (id == bay->content_id)
+                return;
+
+        bay->value_count += msecs_to_jiffies(MB_POLL_DELAY);
+        if (bay->value_count >= msecs_to_jiffies(MB_STABLE_DELAY)) {
+                /* If the device type changes without going thru
+                 * "MB_NO", we force a pass by "MB_NO" to make sure
+                 * things are properly reset
+                 */
+                if ((id != MB_NO) && (bay->content_id != MB_NO)) {
+                        id = MB_NO;
+                        pr_debug("mediabay%d: forcing MB_NO\n", bay->index);
+                }
+                pr_debug("mediabay%d: switching to %d\n", bay->index, id);
+                set_mb_power(bay, id != MB_NO);
+                bay->content_id = id;
+                if (id >= MB_NO || id < 0)
+                        printk(KERN_INFO "mediabay%d: Bay is now empty\n", bay->index);
+                else
+                        printk(KERN_INFO "mediabay%d: Bay contains %s\n",
+                               bay->index, mb_content_types[id]);
         }
 }
 
-#ifdef CONFIG_BLK_DEV_IDE_PMAC
-int check_media_bay(struct device_node *which_bay, int what)
+int check_media_bay(struct macio_dev *baydev)
 {
-        int     i;
+        struct media_bay_info* bay;
+        int id;
 
-        for (i=0; i<media_bay_count; i++)
-                if (media_bays[i].mdev && which_bay == media_bays[i].mdev->ofdev.node) {
-                        if ((what == media_bays[i].content_id) && media_bays[i].state == mb_up)
-                                return 0;
-                        media_bays[i].cd_index = -1;
-                        return -EINVAL;
-                }
-        return -ENODEV;
+        if (baydev == NULL)
+                return MB_NO;
+
+        /* This returns an instant snapshot, not locking, sine
+         * we may be called with the bay lock held. The resulting
+         * fuzzyness of the result if called at the wrong time is
+         * not actually a huge deal
+         */
+        bay = macio_get_drvdata(baydev);
+        if (bay == NULL)
+                return MB_NO;
+        id = bay->content_id;
+        if (bay->state != mb_up)
+                return MB_NO;
+        if (id == MB_FD1)
+                return MB_FD;
+        return id;
 }
-EXPORT_SYMBOL(check_media_bay);
+EXPORT_SYMBOL_GPL(check_media_bay);
 
-int check_media_bay_by_base(unsigned long base, int what)
+void lock_media_bay(struct macio_dev *baydev)
 {
-        int     i;
-
-        for (i=0; i<media_bay_count; i++)
-                if (media_bays[i].mdev && base == (unsigned long) media_bays[i].cd_base) {
-                        if ((what == media_bays[i].content_id) && media_bays[i].state == mb_up)
-                                return 0;
-                        media_bays[i].cd_index = -1;
-                        return -EINVAL;
-                } 
+        struct media_bay_info* bay;
 
-        return -ENODEV;
+        if (baydev == NULL)
+                return;
+        bay = macio_get_drvdata(baydev);
+        if (bay == NULL)
+                return;
+        mutex_lock(&bay->lock);
+        bay->user_lock = 1;
 }
-EXPORT_SYMBOL_GPL(check_media_bay_by_base);
+EXPORT_SYMBOL_GPL(lock_media_bay);
 
-int media_bay_set_ide_infos(struct device_node* which_bay, unsigned long base,
-                            int irq, ide_hwif_t *hwif)
+void unlock_media_bay(struct macio_dev *baydev)
 {
-        int     i;
+        struct media_bay_info* bay;
 
-        for (i=0; i<media_bay_count; i++) {
-                struct media_bay_info* bay = &media_bays[i];
-
-                if (bay->mdev && which_bay == bay->mdev->ofdev.node) {
-                        int timeout = 5000, index = hwif->index;
-                        
-                        mutex_lock(&bay->lock);
-
-                        bay->cd_port    = hwif;
-                        bay->cd_base    = (void __iomem *) base;
-                        bay->cd_irq     = irq;
-
-                        if ((MB_CD != bay->content_id) || bay->state != mb_up) {
-                                mutex_unlock(&bay->lock);
-                                return 0;
-                        }
-                        printk(KERN_DEBUG "Registered ide%d for media bay %d\n", index, i);
-                        do {
-                                if (MB_IDE_READY(i)) {
-                                        bay->cd_index   = index;
-                                        mutex_unlock(&bay->lock);
-                                        return 0;
-                                }
-                                mdelay(1);
-                        } while(--timeout);
-                        printk(KERN_DEBUG "Timeount waiting IDE in bay %d\n", i);
-                        mutex_unlock(&bay->lock);
-                        return -ENODEV;
-                }
+        if (baydev == NULL)
+                return;
+        bay = macio_get_drvdata(baydev);
+        if (bay == NULL)
+                return;
+        if (bay->user_lock) {
+                bay->user_lock = 0;
+                mutex_unlock(&bay->lock);
         }
+}
+EXPORT_SYMBOL_GPL(unlock_media_bay);
 
-        return -ENODEV;
+static int mb_broadcast_hotplug(struct device *dev, void *data)
+{
+        struct media_bay_info* bay = data;
+        struct macio_dev *mdev;
+        struct macio_driver *drv;
+        int state;
+
+        if (dev->bus != &macio_bus_type)
+                return 0;
+
+        state = bay->state == mb_up ? bay->content_id : MB_NO;
+        if (state == MB_FD1)
+                state = MB_FD;
+        mdev = to_macio_device(dev);
+        drv = to_macio_driver(dev->driver);
+        if (dev->driver && drv->mediabay_event)
+                drv->mediabay_event(mdev, state);
+        return 0;
 }
-EXPORT_SYMBOL_GPL(media_bay_set_ide_infos);
-#endif /* CONFIG_BLK_DEV_IDE_PMAC */
 
 static void media_bay_step(int i)
 {
@@ -497,8 +474,8 @@ static void media_bay_step(int i)
         if (bay->state != mb_powering_down)
             poll_media_bay(bay);
 
-        /* If timer expired or polling IDE busy, run state machine */
-        if ((bay->state != mb_ide_waiting) && (bay->timer != 0)) {
+        /* If timer expired run state machine */
+        if (bay->timer != 0) {
                 bay->timer -= msecs_to_jiffies(MB_POLL_DELAY);
                 if (bay->timer > 0)
                         return;
@@ -508,100 +485,50 @@ static void media_bay_step(int i)
         switch(bay->state) {
         case mb_powering_up:
                 if (bay->ops->setup_bus(bay, bay->last_value) < 0) {
-                        MBDBG("mediabay%d: device not supported (kind:%d)\n", i, bay->content_id);
+                        pr_debug("mediabay%d: device not supported (kind:%d)\n",
+                                 i, bay->content_id);
                         set_mb_power(bay, 0);
                         break;
                 }
                 bay->timer = msecs_to_jiffies(MB_RESET_DELAY);
                 bay->state = mb_enabling_bay;
-                MBDBG("mediabay%d: enabling (kind:%d)\n", i, bay->content_id);
+                pr_debug("mediabay%d: enabling (kind:%d)\n", i, bay->content_id);
                 break;
         case mb_enabling_bay:
                 bay->ops->un_reset(bay);
                 bay->timer = msecs_to_jiffies(MB_SETUP_DELAY);
                 bay->state = mb_resetting;
-                MBDBG("mediabay%d: waiting reset (kind:%d)\n", i, bay->content_id);
+                pr_debug("mediabay%d: releasing bay reset (kind:%d)\n",
+                         i, bay->content_id);
                 break;
         case mb_resetting:
                 if (bay->content_id != MB_CD) {
-                        MBDBG("mediabay%d: bay is up (kind:%d)\n", i, bay->content_id);
+                        pr_debug("mediabay%d: bay is up (kind:%d)\n", i,
+                                 bay->content_id);
                         bay->state = mb_up;
+                        device_for_each_child(&bay->mdev->ofdev.dev,
+                                              bay, mb_broadcast_hotplug);
                         break;
                 }
-#ifdef CONFIG_BLK_DEV_IDE_PMAC
-                MBDBG("mediabay%d: waiting IDE reset (kind:%d)\n", i, bay->content_id);
+                pr_debug("mediabay%d: releasing ATA reset (kind:%d)\n",
+                         i, bay->content_id);
                 bay->ops->un_reset_ide(bay);
                 bay->timer = msecs_to_jiffies(MB_IDE_WAIT);
                 bay->state = mb_ide_resetting;
-#else
-                printk(KERN_DEBUG "media-bay %d is ide (not compiled in kernel)\n", i);
-                set_mb_power(bay, 0);
-#endif /* CONFIG_BLK_DEV_IDE_PMAC */
                 break;
-#ifdef CONFIG_BLK_DEV_IDE_PMAC
+
         case mb_ide_resetting:
-                bay->timer = msecs_to_jiffies(MB_IDE_TIMEOUT);
-                bay->state = mb_ide_waiting;
-                MBDBG("mediabay%d: waiting IDE ready (kind:%d)\n", i, bay->content_id);
+                pr_debug("mediabay%d: bay is up (kind:%d)\n", i, bay->content_id);
+                bay->state = mb_up;
+                device_for_each_child(&bay->mdev->ofdev.dev,
+                                      bay, mb_broadcast_hotplug);
                 break;
-        case mb_ide_waiting:
-                if (bay->cd_base == NULL) {
-                        bay->timer = 0;
-                        bay->state = mb_up;
-                        MBDBG("mediabay%d: up before IDE init\n", i);
-                        break;
-                } else if (MB_IDE_READY(i)) {
-                        bay->timer = 0;
-                        bay->state = mb_up;
-                        if (bay->cd_index < 0) {
-                                printk("mediabay %d, registering IDE...\n", i);
-                                pmu_suspend();
-                                ide_port_scan(bay->cd_port);
-                                if (bay->cd_port->present)
-                                        bay->cd_index = bay->cd_port->index;
-                                pmu_resume();
-                        }
-                        if (bay->cd_index == -1) {
-                                /* We eventually do a retry */
-                                bay->cd_retry++;
-                                printk("IDE register error\n");
-                                set_mb_power(bay, 0);
-                        } else {
-                                printk(KERN_DEBUG "media-bay %d is ide%d\n", i, bay->cd_index);
-                                MBDBG("mediabay %d IDE ready\n", i);
-                        }
-                        break;
-                } else if (bay->timer > 0)
-                        bay->timer -= msecs_to_jiffies(MB_POLL_DELAY);
-                if (bay->timer <= 0) {
-                        printk("\nIDE Timeout in bay %d !, IDE state is: 0x%02x\n",
-                               i, readb(bay->cd_base + 0x70));
-                        MBDBG("mediabay%d: nIDE Timeout !\n", i);
-                        set_mb_power(bay, 0);
-                        bay->timer = 0;
-                }
-                break;
-#endif /* CONFIG_BLK_DEV_IDE_PMAC */
+
         case mb_powering_down:
                 bay->state = mb_empty;
-#ifdef CONFIG_BLK_DEV_IDE_PMAC
-                if (bay->cd_index >= 0) {
-                        printk(KERN_DEBUG "Unregistering mb %d ide, index:%d\n", i,
-                               bay->cd_index);
-                        ide_port_unregister_devices(bay->cd_port);
-                        bay->cd_index = -1;
-                }
-                if (bay->cd_retry) {
-                        if (bay->cd_retry > MAX_CD_RETRIES) {
-                                /* Should add an error sound (sort of beep in dmasound) */
-                                printk("\nmedia-bay %d, IDE device badly inserted or unrecognised\n", i);
-                        } else {
-                                /* Force a new power down/up sequence */
-                                bay->content_id = MB_NO;
-                        }
-                }
-#endif /* CONFIG_BLK_DEV_IDE_PMAC */
-                MBDBG("mediabay%d: end of power down\n", i);
+                device_for_each_child(&bay->mdev->ofdev.dev,
+                                      bay, mb_broadcast_hotplug);
+                pr_debug("mediabay%d: end of power down\n", i);
                 break;
         }
 }
@@ -676,11 +603,6 @@ static int __devinit media_bay_attach(struct macio_dev *mdev, const struct of_de
         bay->last_value = bay->ops->content(bay);
         bay->value_count = msecs_to_jiffies(MB_STABLE_DELAY);
         bay->state = mb_empty;
-        do {
-                msleep(MB_POLL_DELAY);
-                media_bay_step(i);
-        } while((bay->state != mb_empty) &&
-                (bay->state != mb_up));
 
         /* Mark us ready by filling our mdev data */
         macio_set_drvdata(mdev, bay);
@@ -725,7 +647,7 @@ static int media_bay_resume(struct macio_dev *mdev)
                 set_mb_power(bay, 0);
                 msleep(MB_POWER_DELAY);
                 if (bay->ops->content(bay) != bay->content_id) {
-                        printk("mediabay%d: content changed during sleep...\n", bay->index);
+                        printk("mediabay%d: Content changed during sleep...\n", bay->index);
                         mutex_unlock(&bay->lock);
                         return 0;
                 }
@@ -733,9 +655,6 @@ static int media_bay_resume(struct macio_dev *mdev)
                 bay->last_value = bay->content_id;
                 bay->value_count = msecs_to_jiffies(MB_STABLE_DELAY);
                 bay->timer = msecs_to_jiffies(MB_POWER_DELAY);
-#ifdef CONFIG_BLK_DEV_IDE_PMAC
-                bay->cd_retry = 0;
-#endif
                 do {
                         msleep(MB_POLL_DELAY);
                         media_bay_step(bay->index);
@@ -823,9 +742,6 @@ static int __init media_bay_init(void)
         for (i=0; i<MAX_BAYS; i++) {
                 memset((char *)&media_bays[i], 0, sizeof(struct media_bay_info));
                 media_bays[i].content_id        = -1;
-#ifdef CONFIG_BLK_DEV_IDE_PMAC
-                media_bays[i].cd_index          = -1;
-#endif
         }
         if (!machine_is(powermac))
                 return 0;