mmc: add bus handler

Delegate protocol handling to "bus handlers". This allows the core to
just handle the task of arbitrating the bus. Initialisation and
pampering of cards is now done by the different bus handlers.

This design also allows MMC and SD (and later SDIO) to be more cleanly
separated, allowing easier maintenance.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 6 insertions, 1 deletions

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 43bf6a5c398d..efae87b5c4e7 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -131,6 +131,8 @@ struct mmc_host {
         unsigned int            max_blk_count;  /* maximum number of blocks in one req */
 
         /* private data */
+        spinlock_t              lock;           /* lock for claim and bus ops */
+
         struct mmc_ios          ios;            /* current io bus settings */
         u32                     ocr;            /* the current OCR setting */
 
@@ -141,7 +143,6 @@ struct mmc_host {
         struct mmc_card         *card;          /* device attached to this host */
 
         wait_queue_head_t       wq;
-        spinlock_t              lock;           /* claimed lock */
         unsigned int            claimed:1;      /* host exclusively claimed */
 
         struct delayed_work     detect;
@@ -149,6 +150,10 @@ struct mmc_host {
         unsigned int            removed:1;      /* host is being removed */
 #endif
 
+        const struct mmc_bus_ops *bus_ops;      /* current bus driver */
+        unsigned int            bus_refs;       /* reference counter */
+        unsigned int            bus_dead:1;     /* bus has been released */
+
         unsigned long           private[0] ____cacheline_aligned;
 };