Add support for Freescale's mx35pdk board.

The patch adds suupport for the Freescale's mx35pdk board
(known as well as mx35_3stack).

The board boots from the NOR flash. Following devices
are supported:
 - two ethernet devices (FEC and SMC911x on debug board)
 - I2C
 - PMIC (MC13892) via I2C interface
 - UART
 - NOR flash (64MB)
 - NAND flash (2GB)
 - basic access to mc9sdz60 registers via I2C interface

Signed-off-by: Stefano Babic <sbabic@denx.de>

1 files changed, 188 insertions, 0 deletions

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+Overview
+--------------
+
+mx35pdk (known als as mx35_3stack) is a development board by Freescale.
+It consists of three pluggable board:
+	- CPU module, with CPU, RAM, flash
+	- Personality board, with most interfaces (USB, Network,..)
+	- Debug board with JTAG header.
+
+The board is usually delivered with redboot. This howto explains how to boot
+a linux kernel and how to replace the original bootloader with U-Boot.
+
+The board is delivered with Redboot on the NAND flash. It is possible to
+switch the boot device with the switches SW1-SW2 on the Personality board,
+and with SW5-SW10 on the Debug board.
+
+Delivered Redboot script to start the kernel
+---------------------------------------------------
+
+In redboot the following script is stored:
+
+fis load kernel
+exec -c "noinitrd console=ttymxc0,115200 root=/dev/mtdblock8 rw rootfstype=jffs2 ip=dhcp fec_mac=00:04:9F:00:E7:76"
+
+Kernel is taken from flash. The image is in zImage format.
+
+Booting from NET, rootfs on NFS:
+-----------------------------------
+
+To change the script in redboot:
+
+load -r -b 0x100000 <path_to_zImage>
+exec -c "noinitrd console=ttymxc0,115200 root=/dev/nfsroot rootfstype=nfsroot nfsroot=192.168.1.1:/opt/eldk-4.2-arm/armVFP rw ip=dhcp"
+
+If the ip address is not set, you can set it with :
+
+ip_address -l <board_ip/netmask> -h <server_ip>
+
+Linux partitions:
+---------------------------
+
+As default, the board is shipped with these partition tables for NAND
+and for NOR:
+
+Creating 5 MTD partitions on "NAND 2GiB 3,3V 8-bit":
+0x00000000-0x00100000 : "nand.bootloader"
+0x00100000-0x00600000 : "nand.kernel"
+0x00600000-0x06600000 : "nand.rootfs"
+0x06600000-0x06e00000 : "nand.configure"
+0x06e00000-0x80000000 : "nand.userfs"
+
+Creating 6 MTD partitions on "mxc_nor_flash.0":
+0x00000000-0x00080000 : "Bootloader"
+0x00080000-0x00480000 : "nor.Kernel"
+0x00480000-0x02280000 : "nor.userfs"
+0x02280000-0x03e80000 : "nor.rootfs"
+0x01fe0000-0x01fe3000 : "FIS directory"
+0x01fff000-0x04000000 : "Redboot config"
+
+NAND partitions can be recognized enabling in kernel CONFIG_MTD_REDBOOT_PARTS.
+For this board, CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK should be set to 2.
+
+However, the setup in redboot is not correct and does not use the whole flash.
+
+Better solution is to use the kernel parameter mtdparts.
+Here the resulting script to be defined in RedBoot with fconfig:
+
+load -r -b 0x100000 sbabic/mx35pdk/zImage.2.6.37
+exec -c "noinitrd console=ttymxc0,115200 root=/dev/nfsroot rootfstype=nfsroot nfsroot=192.168.1.1:/opt/eldk-4.2-arm/arm rw ip=dhcp mtdparts=mxc_nand:1m(boot),5m(linux),96m(root),8m(cfg),1938m(user);physmap-flash.0:512k(b),4m(k),30m(u),28m(r)"
+
+Flashing U-Boot
+--------------------------------
+
+There are two options: the original bootloader in NAND can be replaced with
+u-boot, or u-boot can be stored on the NOR flash without erasing
+the delivered bootloader.
+The boot storage can be select using the switches on the personality board
+(SW1-SW2) and on the DEBUG board (SW4-SW10).
+
+The second option is to be preferred if you have not a JTAG debugger.
+If something goes wrong flashing the bootloader, it is always possible to
+recover the board booting from the other device.
+
+Replacing the bootloader on the NAND
+--------------------------------------
+To replace RedBoot with U-Boot, the easy way is to do this in linux.
+Start the kernel with the suggested options. Make sure to have set the
+mtdparts exactly as described, because this matches the layout on the
+mx35pdk.
+
+You should see in your boot log the following entries for the NAND
+flash:
+
+5 cmdlinepart partitions found on MTD device mxc_nand
+Creating 5 MTD partitions on "mxc_nand":
+0x000000000000-0x000000100000 : "boot"
+0x000000100000-0x000000600000 : "linux"
+0x000000600000-0x000006600000 : "root"
+0x000006600000-0x000006e00000 : "cfg"
+0x000006e00000-0x000080000000 : "user"
+
+You can use the utilities flash_eraseall and nandwrite to put
+u-boot on the NAND. The bootloader is marked as "boot", and 1MB is
+reserved. If everything is correct, this partition is accessed as
+/dev/mtd4. However, check if it is correct with "cat /proc/mtd" and
+get the device node from the partition name:
+
+$ cat /proc/mtd | grep boot
+
+I suggest you try the utilities on a different partition to be sure
+if everything works correctly. If not, and you remove RedBoot, you have to
+reinstall it using the ATK tool as suggested by Freescale, or using a
+JTAG debugger.
+
+I report the versions of the utilities I used (they are provided with ELDK):
+
+-bash-3.2# nandwrite --version
+nandwrite $Revision: 1.32 $
+
+flash_eraseall --version
+flash_eraseall $Revision: 1.22 $
+
+nandwrite reports a warning if the file to be saved is not sector aligned.
+This should have no consequences, but I preferred to pad u-boot.bin
+to get no problem at all.
+$ dd if=/dev/zero of=zeros bs=1 count=74800
+$ cat u-boot.bin zeros > u-boot-padded.bin
+
+To erase the partition:
+$ flash_eraseall /dev/mtd4
+
+Writing u-boot:
+
+$ nandwrite /dev/mtd4 u-boot-padded.bin
+
+Now U-Boot is stored on the booting partition.
+
+To boot from NAND, you have to select the switches as follows:
+
+Personality board
+	SW2	1, 4, 5 on
+		2, 3, 6, 7, 8 off
+	SW1	all off
+
+Debug Board:
+	SW5	0
+	SW6	0
+	SW7	0
+	SW8	1
+	SW9	1
+	SW10	0
+
+
+Saving U-Boot in the NOR flash
+---------------------------------
+
+The procedure to save in the NOR flash is quite the same as to write into the NAND.
+
+Check the partition for boot in the NOR flash. Setting the mtdparts as reported,
+the boot partition should be /dev/mtd0.
+
+Creating 6 MTD partitions on "mxc_nor_flash.0":
+0x00000000-0x00080000 : "Bootloader"
+0x00080000-0x00480000 : "nor.Kernel"
+0x00480000-0x02280000 : "nor.userfs"
+0x02280000-0x03e80000 : "nor.rootfs"
+0x01fe0000-0x01fe3000 : "FIS directory"
+0x01fff000-0x04000000 : "Redboot config"
+
+To erase the whole partition:
+$ flash_eraseall /dev/mtd0
+
+Writing u-boot:
+dd if=u-boot.bin of=/dev/mtd0
+
+To boot from NOR, you have to select the switches as follows:
+
+Personality board
+	SW2	all off
+	SW1	all off
+
+Debug Board:
+	SW5	0
+	SW6	0
+	SW7	0
+	SW8	1
+	SW9	1
+	SW10	0