libata: make SFF support optional
Now that SFF support is completely separated out from the core layer,
it can be made optional. Add CONFIG_ATA_SFF and let SFF drivers
depend on it. If CONFIG_ATA_SFF isn't set, all codes in libata-sff.c
and data structures for SFF support are disabled. This saves good
number of bytes for small systems.
Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index 0511e6f..e6e41b2 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -78,6 +78,6 @@
# Should be last libata driver
obj-$(CONFIG_PATA_LEGACY) += pata_legacy.o
-libata-objs := libata-core.o libata-scsi.o libata-sff.o libata-eh.o \
- libata-pmp.o
+libata-objs := libata-core.o libata-scsi.o libata-eh.o libata-pmp.o
+libata-$(CONFIG_ATA_SFF) += libata-sff.o
libata-$(CONFIG_ATA_ACPI) += libata-acpi.o