sunxi: Enable DFU for RAM

The DFU protocol implementation in U-Boot is much faster than the
FEL protocol implementation in the boot ROM on Allwinner devices.
Using DFU instead of FEL improves the USB transfer speed from
500-900 KB/s to 3.2-3.7 MB/s. This is particularly useful for
reducing the time needed for booting systems with large initrd
images.

FEL is still useful for loading the U-Boot bootloader and a boot
script, which may then activate DFU in the following way:

   setenv dfu_alt_info ${dfu_alt_info_ram}
   dfu 0 ram 0
   bootm ${kernel_addr_r} ${ramdisk_addr_r} ${fdt_addr_r}

The rest of the files can be transferred to the device using the
"dfu-util" tool.

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

include/configs/sunxi-common.h

@@ -335,6 +335,7 @@ extern int soft_i2c_gpio_scl;
 #define CONFIG_USB_GADGET_VBUS_DRAW	0
 
 #define CONFIG_USB_GADGET_DOWNLOAD
+#define CONFIG_USB_FUNCTION_DFU
 #define CONFIG_USB_FUNCTION_FASTBOOT
 #define CONFIG_USB_FUNCTION_MASS_STORAGE
 #endif
@@ -345,6 +346,11 @@ extern int soft_i2c_gpio_scl;
 #define CONFIG_G_DNL_MANUFACTURER	"Allwinner Technology"
 #endif
 
+#ifdef CONFIG_USB_FUNCTION_DFU
+#define CONFIG_CMD_DFU
+#define CONFIG_DFU_RAM
+#endif
+
 #ifdef CONFIG_USB_FUNCTION_FASTBOOT
 #define CONFIG_CMD_FASTBOOT
 #define CONFIG_FASTBOOT_BUF_ADDR	CONFIG_SYS_LOAD_ADDR
@@ -392,13 +398,26 @@ extern int soft_i2c_gpio_scl;
  * 32M uncompressed kernel, 16M compressed kernel, 1M fdt,
  * 1M script, 1M pxe and the ramdisk at the end.
  */
+
+#define KERNEL_ADDR_R  __stringify(SDRAM_OFFSET(2000000))
+#define FDT_ADDR_R     __stringify(SDRAM_OFFSET(3000000))
+#define SCRIPT_ADDR_R  __stringify(SDRAM_OFFSET(3100000))
+#define PXEFILE_ADDR_R __stringify(SDRAM_OFFSET(3200000))
+#define RAMDISK_ADDR_R __stringify(SDRAM_OFFSET(3300000))
+
 #define MEM_LAYOUT_ENV_SETTINGS \
 	"bootm_size=0xa000000\0" \
-	"kernel_addr_r=" __stringify(SDRAM_OFFSET(2000000)) "\0" \
-	"fdt_addr_r=" __stringify(SDRAM_OFFSET(3000000)) "\0" \
-	"scriptaddr=" __stringify(SDRAM_OFFSET(3100000)) "\0" \
-	"pxefile_addr_r=" __stringify(SDRAM_OFFSET(3200000)) "\0" \
-	"ramdisk_addr_r=" __stringify(SDRAM_OFFSET(3300000)) "\0"
+	"kernel_addr_r=" KERNEL_ADDR_R "\0" \
+	"fdt_addr_r=" FDT_ADDR_R "\0" \
+	"scriptaddr=" SCRIPT_ADDR_R "\0" \
+	"pxefile_addr_r=" PXEFILE_ADDR_R "\0" \
+	"ramdisk_addr_r=" RAMDISK_ADDR_R "\0"
+
+#define DFU_ALT_INFO_RAM \
+	"dfu_alt_info_ram=" \
+	"kernel ram " KERNEL_ADDR_R " 0x1000000;" \
+	"fdt ram " FDT_ADDR_R " 0x100000;" \
+	"ramdisk ram " RAMDISK_ADDR_R " 0x4000000\0"
 
 #ifdef CONFIG_MMC
 #define BOOT_TARGET_DEVICES_MMC(func) func(MMC, mmc, 0)
@@ -480,6 +499,7 @@ extern int soft_i2c_gpio_scl;
 #define CONFIG_EXTRA_ENV_SETTINGS \
 	CONSOLE_ENV_SETTINGS \
 	MEM_LAYOUT_ENV_SETTINGS \
+	DFU_ALT_INFO_RAM \
 	"fdtfile=" CONFIG_DEFAULT_DEVICE_TREE ".dtb\0" \
 	"console=ttyS0,115200\0" \
 	BOOTCMD_SUNXI_COMPAT \