libata: make PMP support optional
Make PMP support optional by adding CONFIG_SATA_PMP and leaving out
libata-pmp.c if it isn't set. PMP helpers return constant values if
PMP support is not enabled and PMP declarations alias non-PMP
counterparts. This makes the compiler to leave out PMP related part
out and LLDs to use non-PMP counterparts automatically.
Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 48c8fc5..3eb6035 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -41,6 +41,12 @@
You can disable this at kernel boot time by using the
option libata.noacpi=1
+config SATA_PMP
+ bool "SATA Port Multiplier support"
+ default y
+ help
+ This option adds support for SATA Port Multipliers.
+
config SATA_AHCI
tristate "AHCI SATA support"
depends on PCI
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index e6e41b2..1fbc2aa 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -78,6 +78,7 @@
# Should be last libata driver
obj-$(CONFIG_PATA_LEGACY) += pata_legacy.o
-libata-objs := libata-core.o libata-scsi.o libata-eh.o libata-pmp.o
+libata-objs := libata-core.o libata-scsi.o libata-eh.o
libata-$(CONFIG_ATA_SFF) += libata-sff.o
+libata-$(CONFIG_SATA_PMP) += libata-pmp.o
libata-$(CONFIG_ATA_ACPI) += libata-acpi.o
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 42b30e3..4aeeabb 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -203,9 +203,26 @@
extern void ata_eh_finish(struct ata_port *ap);
/* libata-pmp.c */
+#ifdef CONFIG_SATA_PMP
extern int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *val);
extern int sata_pmp_scr_write(struct ata_link *link, int reg, u32 val);
extern int sata_pmp_attach(struct ata_device *dev);
+#else /* CONFIG_SATA_PMP */
+static inline int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *val)
+{
+ return -EINVAL;
+}
+
+static inline int sata_pmp_scr_write(struct ata_link *link, int reg, u32 val)
+{
+ return -EINVAL;
+}
+
+static inline int sata_pmp_attach(struct ata_device *dev)
+{
+ return -EINVAL;
+}
+#endif /* CONFIG_SATA_PMP */
/* libata-sff.c */
#ifdef CONFIG_ATA_SFF