imx6: Add support for Toradex Apalis family of CoMs

This patch adds support for the following computer on modules (CoM) from
Toradex[A]:

 Apalis iMX6 Quad 2GB IT - i.MX 6Quad 800MHz, 2GB DDR3, 4GB eMMC
                                             -40° to +85° C Temp
 Apalis iMX6 Quad 1GB    - i.MX 6Quad 1GHz,   1GB DDR3, 4GB eMMC
                                               0° to +70° C Temp
 Apalis iMX6 Dual 1GB IT - i.MX 6Dual 800MHz, 1GB DDR3, 4GB eMMC
                                             -40° to +85° C Temp
 Apalis iMX6 Dual 512MB  - i.MX 6Dual 1GHz, 512MB DDR3, 4GB eMMC
                                               0° to +70° C Temp

I've developed and tested it on Quad 2GB IT v1.1A and Dual 512MB v1.1A
CoMs, using Ixora[B] carrier board v1.0A, but it should hopefuly work on
Eval[C] board as well.

A. https://www.toradex.com/computer-on-modules/apalis-arm-family/nxp-freescale-imx-6
B. https://www.toradex.com/products/carrier-board/ixora-carrier-board
C. https://www.toradex.com/products/carrier-board/apalis-evaluation-board

Flashing/recovery instructions:

 1. Download and compile imx_loader for OpenWrt from
    https://github.com/ynezz/imx_loader

 2. Enter recovery mode as desribed in
    https://developer.toradex.com/knowledge-base/imx-recovery-mode

 3. Connect board via USB to the host computer, check that it's connected
    by lsusb:

    15a2:0054 Freescale Semiconductor, Inc. i.MX 6Dual/6Quad SystemOnChip
              in RecoveryMode

 4. Copy following OpenWrt images to imx_loader directory:
         SPL
         u-boot.img
         u-boot-with-spl.imx
         openwrt-imx6-apalis-recovery.scr
         openwrt-imx6-apalis-squashfs.combined.bin

 5. Run imx_usb in imx_loader directory

Signed-off-by: Petr Štetiar <ynezz@true.cz>

target/linux/imx6/image/Makefile

@@ -58,6 +58,12 @@ define Build/boot-scr
 	$(BIN_DIR)/boot.scr
 endef
 
+define Build/recovery-scr
+	mkimage -A arm -O linux -T script -C none -a 0 -e 0 \
+	-n '$(DEVICE_ID) OpenWrt recovery bootscript' \
+	-d ./recovery-$(DEVICE_NAME) $@
+endef
+
 define Build/imx6-combined-image-prepare
 	rm -rf $@.boot
 	mkdir -p $@.boot
@@ -101,6 +107,10 @@ define Build/imx6-sdcard
 	$(Build/imx6-combined-image-clean)
 endef
 
+define Build/apalis-emmc
+	$(Build/imx6-combined-image-prepare)
+	$(Build/imx6-combined-image)
+	$(Build/imx6-combined-image-clean)
 endef
 
 #################################################
@@ -190,4 +200,27 @@ define Device/cubox-i
 endef
 TARGET_DEVICES += cubox-i
 
+define Device/apalis
+  DEVICE_TITLE := Toradex Apalis family
+  SUPPORTED_DEVICES := apalis,ixora apalis,eval
+  DEVICE_DTS := \
+	  imx6q-apalis-eval \
+	  imx6q-apalis-ixora \
+	  imx6q-apalis-ixora-v1.1
+  DEVICE_PACKAGES := \
+	kmod-can kmod-can-flexcan kmod-can-raw \
+	kmod-leds-gpio kmod-gpio-button-hotplug \
+	kmod-pps-gpio kmod-rtc-ds1307
+  BOOT_SCRIPT := bootscript-apalis
+  UBOOT := apalis_imx6
+  FILESYSTEMS := squashfs
+  IMAGES := combined.bin sysupgrade.bin
+  IMAGE_NAME = $$(IMAGE_PREFIX)-$$(1).$$(2)
+  IMAGE/combined.bin := append-rootfs | pad-extra 128k | apalis-emmc
+  IMAGE/sysupgrade.bin := sysupgrade-tar | append-metadata
+  ARTIFACTS := recovery.scr
+  ARTIFACT/recovery.scr := recovery-scr
+endef
+TARGET_DEVICES += apalis
+
 $(eval $(call BuildImage))

target/linux/imx6/image/bootscript-apalis

@@ -0,0 +1,20 @@
+echo "Toradex Apalis OpenWrt Boot script v1.0"
+
+run finduuid
+
+setenv nextcon 0
+setenv fdt_file imx6q-apalis-ixora.dtb
+setenv root root=PARTUUID=${uuid} rootfstype=squashfs rootwait
+setenv bootargs earlyprintk console=${console},${baudrate}n8 ${root}
+setenv fsload ext4load mmc ${mmcbootdev}:${bootpart}
+
+if ${fsload} ${kernel_addr_r} ${boot_file}; then
+	if ${fsload} ${fdt_addr_r} ${fdt_file}; then
+		test -n "$fdt_fixup" && run fdt_fixup
+		bootm ${kernel_addr_r} - ${fdt_addr_r}
+	else
+		echo "Error loading device-tree"
+	fi
+else
+	echo "Error loading kernel image"
+fi

target/linux/imx6/image/recovery-apalis

@@ -0,0 +1,14 @@
+# flash u-boot-with-spl.imx
+# using fixed size of 1M for U-Boot + SPL
+mmc dev 0 1
+mmc write 0x12100000 0x2 0x800
+
+# flash openwrt-imx6-apalis-squashfs.combined.bin
+run set_blkcnt
+mmc dev 0 0
+mmc write 0x12500000 0 ${blkcnt}
+
+env default -f -a
+saveenv
+
+reset