ahci: provide sunxi SATA driver using AHCI platform framework

This enables the necessary clocks, in AHB0 and in PLL6_CFG. This is done
for sun7i only since I don't have access to any other sunxi platforms
with sata included.

The PHY setup is derived from the Alwinner releases and Linux, but is mostly
undocumented.

The Allwinner AHCI controller also requires some magic (and, again,
undocumented) DMA initialisation when starting a port.  This is added under a
suitable ifdef.

This option is enabled for Cubieboard, Cubieboard2 and Cubietruck based on
contents of Linux DTS files, including SATA power pin config taken from the
DTS. All build tested, but runtime tested on Cubieboard2 and Cubietruck only.

Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
diff --git a/include/ahci.h b/include/ahci.h
index 90e8509..35b8a8c 100644
--- a/include/ahci.h
+++ b/include/ahci.h
@@ -58,6 +58,10 @@
 #define PORT_SCR_ERR		0x30 /* SATA phy register: SError */
 #define PORT_SCR_ACT		0x34 /* SATA phy register: SActive */
 
+#ifdef CONFIG_SUNXI_AHCI
+#define PORT_P0DMACR		0x70 /* SUNXI specific "DMA register" */
+#endif
+
 /* PORT_IRQ_{STAT,MASK} bits */
 #define PORT_IRQ_COLD_PRES	(1 << 31) /* cold presence detect */
 #define PORT_IRQ_TF_ERR		(1 << 30) /* task file error */
diff --git a/include/configs/sunxi-common.h b/include/configs/sunxi-common.h
index 8ab6429..1505510 100644
--- a/include/configs/sunxi-common.h
+++ b/include/configs/sunxi-common.h
@@ -57,6 +57,18 @@
 #define PHYS_SDRAM_0			CONFIG_SYS_SDRAM_BASE
 #define PHYS_SDRAM_0_SIZE		0x80000000 /* 2 GiB */
 
+#ifdef CONFIG_AHCI
+#define CONFIG_LIBATA
+#define CONFIG_SCSI_AHCI
+#define CONFIG_SCSI_AHCI_PLAT
+#define CONFIG_SUNXI_AHCI
+#define CONFIG_SYS_SCSI_MAX_SCSI_ID	1
+#define CONFIG_SYS_SCSI_MAX_LUN		1
+#define CONFIG_SYS_SCSI_MAX_DEVICE	(CONFIG_SYS_SCSI_MAX_SCSI_ID * \
+					 CONFIG_SYS_SCSI_MAX_LUN)
+#define CONFIG_CMD_SCSI
+#endif
+
 #define CONFIG_CMD_MEMORY
 #define CONFIG_CMD_SETEXPR