oxnas: add support for 2nd S-ATA port to sata_oxnas driver

similar to mv_sata, use nr-ports attribute from device tree.
import and adapt locking code from vendor GPL sources.
add dma controller handling, it may be used in future to avoid
full core resets similar to the vendor SDK's "progressive cleanup"
function.

this is still very dirty and aimed to first of all do things
quite exactly like the reference code. and it somehow works.
obviously there is lots of room for improvement :)

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

SVN-Revision: 43598

target/linux/oxnas/files/arch/arm/boot/dts/ox820-kd20.dts

@@ -26,6 +26,7 @@
 
 	sata@45900000 {
 		status = "okay";
+		nr-ports = <2>;
 	};
 
 	nand@41000000 {

target/linux/oxnas/files/arch/arm/boot/dts/ox820.dtsi

@@ -286,14 +286,15 @@
 
 	sata@45900000 {
 		compatible = "plxtech,nas782x-sata";
-			/*	port		sgdma		core	*/
-		reg = <0x45900000 0x100>, <0x459B0000 0x10>, <0x459E0000 0x2000>,
-			/*	phy		descriptors (optional)	*/
-			<0x44900000 0x0C>, <0x50000000 0x1000>;
+			/*	ports		dmactl		sgdma	*/
+		reg = <0x45900000 0x20000>, <0x459A0000 0x40>, <0x459B0000 0x20>,
+			/*	core		phy		descriptors (optional)	*/
+			<0x459E0000 0x2000>, <0x44900000 0x0C>, <0x50000000 0x1000>;
 		interrupts = <0 18 0x304>;
 		clocks = <&stdclk 4>;
 		resets = <&rst 11>, <&rst 12>, <&rst 13>;
 		reset-names = "sata", "link", "phy";
+		nr-ports = <1>;
 		status = "disabled";
 	};
 

target/linux/oxnas/patches-3.14/999-libata-hacks.patch

@@ -0,0 +1,60 @@
+Index: linux-3.18-rc7/drivers/ata/libata-core.c
+===================================================================
+--- linux-3.18-rc7.orig/drivers/ata/libata-core.c
++++ linux-3.18-rc7/drivers/ata/libata-core.c
+@@ -1568,6 +1568,14 @@ unsigned ata_exec_internal_sg(struct ata
+ 		return AC_ERR_SYSTEM;
+ 	}
+ 
++	if (ap->ops->acquire_hw && !ap->ops->acquire_hw(ap->port_no, 0, 0)) {
++		spin_unlock_irqrestore(ap->lock, flags);
++		if (!ap->ops->acquire_hw(ap->port_no, 1, (2*HZ))) {
++			return AC_ERR_TIMEOUT;
++		}
++		spin_lock_irqsave(ap->lock, flags);
++	}
++
+ 	/* initialize internal qc */
+ 
+ 	/* XXX: Tag 0 is used for drivers with legacy EH as some
+@@ -4739,6 +4747,9 @@ static struct ata_queued_cmd *ata_qc_new
+ 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
+ 		return NULL;
+ 
++	if (ap->ops->qc_new && ap->ops->qc_new(ap))
++		return NULL;
++
+ 	for (i = 0, tag = ap->last_tag + 1; i < max_queue; i++, tag++) {
+ 		tag = tag < max_queue ? tag : 0;
+ 
+@@ -4805,6 +4816,8 @@ void ata_qc_free(struct ata_queued_cmd *
+ 	if (likely(ata_tag_valid(tag))) {
+ 		qc->tag = ATA_TAG_POISON;
+ 		clear_bit(tag, &ap->qc_allocated);
++		if (ap->ops->qc_free)
++			ap->ops->qc_free(qc);
+ 	}
+ }
+ 
+Index: linux-3.18-rc7/include/linux/libata.h
+===================================================================
+--- linux-3.18-rc7.orig/include/linux/libata.h
++++ linux-3.18-rc7/include/linux/libata.h
+@@ -884,6 +884,8 @@ struct ata_port_operations {
+ 	void (*qc_prep)(struct ata_queued_cmd *qc);
+ 	unsigned int (*qc_issue)(struct ata_queued_cmd *qc);
+ 	bool (*qc_fill_rtf)(struct ata_queued_cmd *qc);
++	int (*qc_new)(struct ata_port *ap);
++	void (*qc_free)(struct ata_queued_cmd *qc);
+ 
+ 	/*
+ 	 * Configuration and exception handling
+@@ -974,6 +976,8 @@ struct ata_port_operations {
+ 	void (*phy_reset)(struct ata_port *ap);
+ 	void (*eng_timeout)(struct ata_port *ap);
+ 
++	int (*acquire_hw)(int port_no, int may_sleep, int timeout_jiffies);
++
+ 	/*
+ 	 * ->inherits must be the last field and all the preceding
+ 	 * fields must be pointers.

target/linux/oxnas/patches-3.18/999-libata-hacks.patch

@@ -0,0 +1,60 @@
+Index: linux-3.18-rc7/drivers/ata/libata-core.c
+===================================================================
+--- linux-3.18-rc7.orig/drivers/ata/libata-core.c
++++ linux-3.18-rc7/drivers/ata/libata-core.c
+@@ -1568,6 +1568,14 @@ unsigned ata_exec_internal_sg(struct ata
+ 		return AC_ERR_SYSTEM;
+ 	}
+ 
++	if (ap->ops->acquire_hw && !ap->ops->acquire_hw(ap->port_no, 0, 0)) {
++		spin_unlock_irqrestore(ap->lock, flags);
++		if (!ap->ops->acquire_hw(ap->port_no, 1, (2*HZ))) {
++			return AC_ERR_TIMEOUT;
++		}
++		spin_lock_irqsave(ap->lock, flags);
++	}
++
+ 	/* initialize internal qc */
+ 
+ 	/* XXX: Tag 0 is used for drivers with legacy EH as some
+@@ -4739,6 +4747,9 @@ static struct ata_queued_cmd *ata_qc_new
+ 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
+ 		return NULL;
+ 
++	if (ap->ops->qc_new && ap->ops->qc_new(ap))
++		return NULL;
++
+ 	for (i = 0, tag = ap->last_tag + 1; i < max_queue; i++, tag++) {
+ 		tag = tag < max_queue ? tag : 0;
+ 
+@@ -4805,6 +4816,8 @@ void ata_qc_free(struct ata_queued_cmd *
+ 	if (likely(ata_tag_valid(tag))) {
+ 		qc->tag = ATA_TAG_POISON;
+ 		clear_bit(tag, &ap->qc_allocated);
++		if (ap->ops->qc_free)
++			ap->ops->qc_free(qc);
+ 	}
+ }
+ 
+Index: linux-3.18-rc7/include/linux/libata.h
+===================================================================
+--- linux-3.18-rc7.orig/include/linux/libata.h
++++ linux-3.18-rc7/include/linux/libata.h
+@@ -884,6 +884,8 @@ struct ata_port_operations {
+ 	void (*qc_prep)(struct ata_queued_cmd *qc);
+ 	unsigned int (*qc_issue)(struct ata_queued_cmd *qc);
+ 	bool (*qc_fill_rtf)(struct ata_queued_cmd *qc);
++	int (*qc_new)(struct ata_port *ap);
++	void (*qc_free)(struct ata_queued_cmd *qc);
+ 
+ 	/*
+ 	 * Configuration and exception handling
+@@ -974,6 +976,8 @@ struct ata_port_operations {
+ 	void (*phy_reset)(struct ata_port *ap);
+ 	void (*eng_timeout)(struct ata_port *ap);
+ 
++	int (*acquire_hw)(int port_no, int may_sleep, int timeout_jiffies);
++
+ 	/*
+ 	 * ->inherits must be the last field and all the preceding
+ 	 * fields must be pointers.