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, 57 insertions, 35 deletions

diff --git a/drivers/ide/pmac.c b/drivers/ide/pmac.c
index 97642a7a79c4..7a4e788cab2f 100644
--- a/drivers/ide/pmac.c
+++ b/drivers/ide/pmac.c
@@ -43,10 +43,7 @@
 #include <asm/pmac_feature.h>
 #include <asm/sections.h>
 #include <asm/irq.h>
-
-#ifndef CONFIG_PPC64
 #include <asm/mediabay.h>
-#endif
 
 #define DRV_NAME "ide-pmac"
 
@@ -59,13 +56,14 @@ typedef struct pmac_ide_hwif {
         int                             irq;
         int                             kind;
         int                             aapl_bus_id;
-        unsigned                        mediabay : 1;
         unsigned                        broken_dma : 1;
         unsigned                        broken_dma_warn : 1;
         struct device_node*             node;
         struct macio_dev                *mdev;
         u32                             timings[4];
         volatile u32 __iomem *          *kauai_fcr;
+        ide_hwif_t                      *hwif;
+
         /* Those fields are duplicating what is in hwif. We currently
          * can't use the hwif ones because of some assumptions that are
          * beeing done by the generic code about the kind of dma controller
@@ -854,6 +852,11 @@ sanitize_timings(pmac_ide_hwif_t *pmif)
         pmif->timings[2] = pmif->timings[3] = value2;
 }
 
+static int on_media_bay(pmac_ide_hwif_t *pmif)
+{
+        return pmif->mdev && pmif->mdev->media_bay != NULL;
+}
+
 /* Suspend call back, should be called after the child devices
  * have actually been suspended
  */
@@ -866,7 +869,7 @@ static int pmac_ide_do_suspend(pmac_ide_hwif_t *pmif)
         disable_irq(pmif->irq);
 
         /* The media bay will handle itself just fine */
-        if (pmif->mediabay)
+        if (on_media_bay(pmif))
                 return 0;
         
         /* Kauai has bus control FCRs directly here */
@@ -889,7 +892,7 @@ static int pmac_ide_do_suspend(pmac_ide_hwif_t *pmif)
 static int pmac_ide_do_resume(pmac_ide_hwif_t *pmif)
 {
         /* Hard reset & re-enable controller (do we really need to reset ? -BenH) */
-        if (!pmif->mediabay) {
+        if (!on_media_bay(pmif)) {
                 ppc_md.feature_call(PMAC_FTR_IDE_RESET, pmif->node, pmif->aapl_bus_id, 1);
                 ppc_md.feature_call(PMAC_FTR_IDE_ENABLE, pmif->node, pmif->aapl_bus_id, 1);
                 msleep(10);
@@ -950,13 +953,11 @@ static void pmac_ide_init_dev(ide_drive_t *drive)
         pmac_ide_hwif_t *pmif =
                 (pmac_ide_hwif_t *)dev_get_drvdata(hwif->gendev.parent);
 
-        if (pmif->mediabay) {
-#ifdef CONFIG_PMAC_MEDIABAY
-                if (check_media_bay_by_base(pmif->regbase, MB_CD) == 0) {
+        if (on_media_bay(pmif)) {
+                if (check_media_bay(pmif->mdev->media_bay) == MB_CD) {
                         drive->dev_flags &= ~IDE_DFLAG_NOPROBE;
                         return;
                 }
-#endif
                 drive->dev_flags |= IDE_DFLAG_NOPROBE;
         }
 }
@@ -1072,26 +1073,23 @@ static int __devinit pmac_ide_setup_device(pmac_ide_hwif_t *pmif,
                 writel(KAUAI_FCR_UATA_MAGIC |
                        KAUAI_FCR_UATA_RESET_N |
                        KAUAI_FCR_UATA_ENABLE, pmif->kauai_fcr);
-
-        pmif->mediabay = 0;
         
         /* Make sure we have sane timings */
         sanitize_timings(pmif);
 
+        /* If we are on a media bay, wait for it to settle and lock it */
+        if (pmif->mdev)
+                lock_media_bay(pmif->mdev->media_bay);
+
         host = ide_host_alloc(&d, hws, 1);
-        if (host == NULL)
-                return -ENOMEM;
-        hwif = host->ports[0];
+        if (host == NULL) {
+                rc = -ENOMEM;
+                goto bail;
+        }
+        hwif = pmif->hwif = host->ports[0];
 
-#ifndef CONFIG_PPC64
-        /* XXX FIXME: Media bay stuff need re-organizing */
-        if (np->parent && np->parent->name
-            && strcasecmp(np->parent->name, "media-bay") == 0) {
-#ifdef CONFIG_PMAC_MEDIABAY
-                media_bay_set_ide_infos(np->parent, pmif->regbase, pmif->irq,
-                                        hwif);
-#endif /* CONFIG_PMAC_MEDIABAY */
-                pmif->mediabay = 1;
+        if (on_media_bay(pmif)) {
+                /* Fixup bus ID for media bay */
                 if (!bidp)
                         pmif->aapl_bus_id = 1;
         } else if (pmif->kind == controller_ohare) {
@@ -1100,9 +1098,7 @@ static int __devinit pmac_ide_setup_device(pmac_ide_hwif_t *pmif,
                  * units, I keep the old way
                  */
                 ppc_md.feature_call(PMAC_FTR_IDE_ENABLE, np, 0, 1);
-        } else
-#endif
-        {
+        } else {
                 /* This is necessary to enable IDE when net-booting */
                 ppc_md.feature_call(PMAC_FTR_IDE_RESET, np, pmif->aapl_bus_id, 1);
                 ppc_md.feature_call(PMAC_FTR_IDE_ENABLE, np, pmif->aapl_bus_id, 1);
@@ -1112,17 +1108,21 @@ static int __devinit pmac_ide_setup_device(pmac_ide_hwif_t *pmif,
         }
 
         printk(KERN_INFO DRV_NAME ": Found Apple %s controller (%s), "
-                         "bus ID %d%s, irq %d\n", model_name[pmif->kind],
-                         pmif->mdev ? "macio" : "PCI", pmif->aapl_bus_id,
-                         pmif->mediabay ? " (mediabay)" : "", hw->irq);
+               "bus ID %d%s, irq %d\n", model_name[pmif->kind],
+               pmif->mdev ? "macio" : "PCI", pmif->aapl_bus_id,
+               on_media_bay(pmif) ? " (mediabay)" : "", hw->irq);
 
         rc = ide_host_register(host, &d, hws);
-        if (rc) {
-                ide_host_free(host);
-                return rc;
-        }
+        if (rc)
+                pmif->hwif = NULL;
 
-        return 0;
+        if (pmif->mdev)
+                unlock_media_bay(pmif->mdev->media_bay);
+
+ bail:
+        if (rc && host)
+                ide_host_free(host);
+        return rc;
 }
 
 static void __devinit pmac_ide_init_ports(struct ide_hw *hw, unsigned long base)
@@ -1362,6 +1362,25 @@ pmac_ide_pci_resume(struct pci_dev *pdev)
         return rc;
 }
 
+#ifdef CONFIG_PMAC_MEDIABAY
+static void pmac_ide_macio_mb_event(struct macio_dev* mdev, int mb_state)
+{
+        pmac_ide_hwif_t *pmif =
+                (pmac_ide_hwif_t *)dev_get_drvdata(&mdev->ofdev.dev);
+
+        switch(mb_state) {
+        case MB_CD:
+                if (!pmif->hwif->present)
+                        ide_port_scan(pmif->hwif);
+                break;
+        default:
+                if (pmif->hwif->present)
+                        ide_port_unregister_devices(pmif->hwif);
+        }
+}
+#endif /* CONFIG_PMAC_MEDIABAY */
+
+
 static struct of_device_id pmac_ide_macio_match[] = 
 {
         {
@@ -1386,6 +1405,9 @@ static struct macio_driver pmac_ide_macio_driver =
         .probe          = pmac_ide_macio_attach,
         .suspend        = pmac_ide_macio_suspend,
         .resume         = pmac_ide_macio_resume,
+#ifdef CONFIG_PMAC_MEDIABAY
+        .mediabay_event = pmac_ide_macio_mb_event,
+#endif
 };
 
 static const struct pci_device_id pmac_ide_pci_match[] = {