[PATCH] libata: Simplex and other mode filtering logic

Add a field to the host_set called 'flags' (was host_set_flags changed
to suit Jeff)
Add a simplex_claimed field so we can remember who owns the DMA channel
Add a ->mode_filter() hook to allow drivers to filter modes
Add docs for mode_filter and set_mode
Filter according to simplex state
Filter cable in core

This provides the needed framework to support all the mode rules found
in the PATA world. The simplex filter deals with 'to spec' simplex DMA
systems found in older chips. The cable filter avoids duplicating the
same rules in each chip driver with PATA. Finally the mode filter is
neccessary because drive/chip combinations have errata that forbid
certain modes with some drives or types of ATA object.

Drive speed setup remains per channel for now and the filters now use
the framework Tejun put into place which cleans them up a lot from the
older libata-pata patches.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 6a9316cbb70b..0d61357604d5 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -294,6 +294,9 @@ struct ata_host_set {
         unsigned int            n_ports;
         void                    *private_data;
         const struct ata_port_operations *ops;
+        unsigned long           flags;
+        int                     simplex_claimed;        /* Keep seperate in case we
+                                                           ever need to do this locked */
         struct ata_port *       ports[0];
 };
 
@@ -423,6 +426,7 @@ struct ata_port_operations {
 
         void (*set_piomode) (struct ata_port *, struct ata_device *);
         void (*set_dmamode) (struct ata_port *, struct ata_device *);
+        unsigned long (*mode_filter) (const struct ata_port *, struct ata_device *, unsigned long);
 
         void (*tf_load) (struct ata_port *ap, const struct ata_taskfile *tf);
         void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf);