libahci: Allow drivers to override start_engine
Allwinner A10 and A20 ARM SoCs have an AHCI sata controller which needs a
special register to be poked before starting the DMA engine.
This register gets reset on an ahci_stop_engine call, so there is no other
place then ahci_start_engine where this poking can be done.
This commit allows drivers to override ahci_start_engine behavior for use by
the Allwinner AHCI driver (and potentially other drivers in the future).
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 2289efd..64d1a99 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -323,6 +323,12 @@
u32 em_msg_type; /* EM message type */
struct clk *clk; /* Only for platforms supporting clk */
void *plat_data; /* Other platform data */
+ /*
+ * Optional ahci_start_engine override, if not set this gets set to the
+ * default ahci_start_engine during ahci_save_initial_config, this can
+ * be overridden anytime before the host is activated.
+ */
+ void (*start_engine)(struct ata_port *ap);
};
extern int ahci_ignore_sss;