B4420 is a subset of B4860. Merge them in config_mpc85xx.h to simplify
the defines.
- Removed #define CONFIG_SYS_FSL_NUM_CLUSTERS as this is used nowhere.
- defined CONFIG_SYS_NUM_FM1_10GEC to 0 for B4420 as it does not have 10G.
Also move CONFIG_E6500 out of B4860QDSds.h into config_mpc85xx.h.
Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Allow DDR clock runs faster than SPD specifes. This may cause memory
failure, but the user should know what is going to happen when using
higher than expected DDR clock.
Signed-off-by: Ed Swarthout <Ed.Swarthout@freescale.com>
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
To align with chassis generation 2 spec, all cores are numbered in sequence.
The cores may reside across multiple clusters. Each cluster has zero to four
cores. The first available core is numbered as core 0. The second available
core is numbered as core 1 and so on.
Core clocks are generated by each clusters. To identify the cluster of each
core, topology registers are examined.
Cluster clock registers are reorganized to be easily indexed.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
T1040 and variants have e5500 cores and are compliant to QorIQ Chassis
Generation 2. The major difference between T1040 and its variants is the
number of cores and the number of L2 switch ports.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
T4160 is a subset of T4240. Merge them in config_mpc85xx.h to simplify
the defines. Also move CONFIG_E6500 out of t4qds.h into config_mpc85xx.h.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
"cpu <num> status" should check if core is disabled before printing
the spin table location.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
While other architectures have enabled these gcc / ld options for some
time on U-Boot itself, ARM has only been doing this on SPL. Enable this
on full U-Boot as well now.
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Tom Rini <trini@ti.com>
Add sama5d3xek support with following feature
- boot from NAND flash, PMECC support, 4bit ECC @ 512 bytes sector
- boot from SPI flash support
- boot from SD card support
- LCD support
- EMAC support
- USB OHCI support
Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
The Freescale MPC8220 Power Architecture processors have long reached
EOL; Freescale does not even list these any more on their web site.
Remove the code to avoid wasting maitaining efforts on dead stuff.
Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Andy Fleming <afleming@gmail.com>
This gives boards flexibility to assign other than default addresses to each
DDR controller. For example, DDR controler 2 can have 0 as the base and DDR
controller 1 has higher memory.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
The workaround has been updated to use a slightly different magic number.
Change from 0x00003000 to 0x30003000.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
This is what we have done for the UTMI PHY on P3041/P5020. Then the PHY
initialization can be reused in kernel without “usb start” command.
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Removed unused declare serdes_get_prtcl() which was no longer needed.
Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
1, Implemented board_ft_fman_fixup_port() to fix port for kernel.
2, Implemented fdt_fixup_board_enet() to fix node status of different
slots and interfaces.
3, Adding detection of slot present for XGMII interface.
4, There is no PHY for XFI, so removed related phy address settings.
Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
When CONFIG_SYS_FSL_QORIQ_CHASSIS2 is not defined, QMAN frequency will not
be initialized, and QMAN will have a wrong frequency display.
Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
T4160 SoC is low power version of T4240. The T4160 combines eight dual
threaded Power Architecture e6500 cores and two memory complexes (CoreNet
platform cache and DDR3 memory controller) with the same high-performance
datapath acceleration, networking, and peripheral bus interfaces.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Protocols are constants. Fix arrays with const prefix.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
The PIR parsing algorithm we used is not only for E6500. It applies to all
SoCs with chassis 2.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Use decimal and hexadecimal for protocol numbers. It helps to match with
SoC user manual.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
T4240 internal UTMI phy is different comparing to previous UTMI PHY
in P3041.
This patch adds USB 2.0 UTMI Dual PHY new memory map and enable it for
T4240.
The phy timing is very sensitive and moving the phy enable code to
cpu_init.c will not work.
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Missing nodes of crypto, pme, etc in device tree is not a fatal error.
Setting up the qman portal should skip the missing node and continue
to finish the rest.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Should check if interleaving is enabled before using interleaving mode.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Lane H on SerDes4 should be SATA2 instead of SATA1
Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
The L1 D-cache on e6500 is write-through. This means that it's not
considered a good idea to have the L1 up and running if the L2 is
disabled. We don't actually *use* the L1 until after the L2 is
brought up on e6500, so go ahead and move the L1 enablement after
that code is done.
Signed-off-by: Andy Fleming <afleming@freescale.com>
Fix ccsr_gur for corenet platform. Remove non-exist registers. Add fuse
status register.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Makes it a bit easier to see if we've properly set them. While
we're in there, modify the accesses to HDBCR0 and HDBCR1 to actually
use those definitions.
Signed-off-by: Andy Fleming <afleming@freescale.com>
The bit positions for FMAN1 freq in RCW is different for B4860.
Also addded a case when FMAN1 frewuency is equal to systembus.
Signed-off-by: Sandeep Singh <Sandeep@freescale.com>
Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Sparc only really sets up the ramdisk, but we should still use
image_setup_linux() so that setup is common across all architectures
that use the FDT.
Cover-letter
Introduce a common image_setup_linux() function
This series continues the work to tidy up the image code. Each
architecture has its own code for setting up ready for booting linux.
An attempt is made here to unify these in a single image_setup_linux()
function.
The part of the image code that deals with FDT is split into image-fdt.c
and a few tweaks are added to make FIT images more viable in SPL.
END
Signed-off-by: Simon Glass <sjg@chromium.org>
Rather than having similar code in m68k, use image_setup_linux() which
should be common across all architectures that use the FDT.
Signed-off-by: Simon Glass <sjg@chromium.org>
Rather than having similar code in powerpc, use image_setup_linux() which
should be common across all architectures that use the FDT.
Signed-off-by: Simon Glass <sjg@chromium.org>
Use the common FDT setup function that is now available in image. Move
the FDT-specific code to a new bootm-fdt.c and remove unused headers
from bootm.c.
Signed-off-by: Simon Glass <sjg@chromium.org>
With fewer #ifdefs the code is more readable and more of the code is
compiled for all boards. Add defines in the header file to control
what features are enabled, and then use if() instead of #ifdef.
Signed-off-by: Simon Glass <sjg@chromium.org>
Coreboot provides a lot of useful timing information. Provide a facility
to add this to bootstage on start-up.
Signed-off-by: Simon Glass <sjg@chromium.org>
While we don't want PCAT timers for timing, we want timer 2 so that we can
still make a beep. Re-purpose the PCAT driver for this, and enable it in
coreboot.
Signed-off-by: Simon Glass <sjg@chromium.org>
This is no longer used since we prefer the more accurate TSC timer, so
remove the dead code.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Graeme Russ <graeme.russ@gmail.com>
Tidy up some old broken and unneeded implementations. These are not used
by coreboot or anything else now.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Reviewed-by: Michael Spang <spang@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Acked-by: Graeme Russ <graeme.russ@gmail.com>
This timer runs at a rate that can be calculated, well over 100MHz. It is
ideal for accurate timing and does not need interrupt servicing.
Tidy up some old broken and unneeded implementations at the same time.
To provide a consistent view of boot time, we use the same time
base as coreboot. Use the base timestamp supplied by coreboot
as U-Boot's base time.
Signed-off-by: Simon Glass <sjg@chromium.org>base
Signed-off-by: Simon Glass <sjg@chromium.org>
The 'Starting linux' message appears twice in the code, but both call
through the same place. Unify these and add calls to bootstage to
mark the occasion.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Michael Spang <spang@chromium.org>
Acked-by: Graeme Russ <graeme.russ@gmail.com>
panic_puts() can be called in early boot to display a message. It might
help with early debugging.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Wai-Hong Tam <waihong@chromium.org>
Several files use the global_data pointer without declaring it. This works
because the declaration is currently a NOP. But still it is better to
fix this so that x86 lines up with other archs.
Signed-off-by: Simon Glass <sjg@chromium.org>
Since we use CONFIG_SYS_GENERIC_BOARD on x86, we don't need this anymore.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Graeme Russ <graeme.russ@gmail.com>
Since we don't have real-mode code now, we can remove this chunk of the link
script.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Graeme Russ <graeme.russ@gmail.com>
Graeme Russ pointed out that this code is no longer used. Remove it.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Graeme Russ <graeme.russ@gmail.com>
Commit 1865286466 (Introduce generic link
section.h symbol files) changed the __bss_end symbol type from char[] to
ulong. This led to wrong relocation parameters which ended up in a not working
u-boot. Unfortunately this is not clear to see cause due to RAM aliasing we
may get a 'half-working' u-boot then.
Fix this by dereferencing the __bss_end symbol where needed.
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
The gpio spec for bf54x and bf60x differ a lot from the old gpio driver for bf5xx.
A lot of machine macros are used to accomodate both code in one gpio driver.
This patch split the old gpio driver and move new gpio2 support to the generic
gpio driver folder.
- To enable gpio2 driver, macro CONFIG_ADI_GPIO2 should be defined in the board's
config header file.
- The gpio2 driver supports bf54x, bf60x and future ADI processors, while the
older gpio driver supports bf50x, bf51x, bf52x, bf53x and bf561.
- All blackfin specific gpio function names are replaced by the generic gpio APIs.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
- Add comments for watchdog event initialization.
- Make sure the writting operation to MMRs are finished.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
- Move blackfin serial driver to the generic driver folder.
- Move blackfin serial headers to blackfin arch head folder.
- Update the include path to blackfin serial header in start up code.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Remove blackfin specific implementation of the generic serial API when
early print macro is defined.
In BFIN_BOOT_BYPASS mode, don't call generic serial_puts, because
early print in bypass mode is running before code binary is relocated
to the link address.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Add softswitch_output command for bf609-ezkit to enable softswitches.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
The early serial should not be configured again in initcode() for BYPASS
boot mode and in start() for the other LDR boot modes.
In BYPASS boot mode, the start up code is located in Nor flash address other
than the DRAM address defined in link script. The code embedded string can't
be addressed by its compile time symbol. Calculate it according to the flash
offset.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Calculate the early uart clock from the system clock registers set by
the bootrom other than the predefine uboot clock macros.
Split the early baudrate setting function and the normal baudrate
setting one.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Define core 1 L1 code sram start address.
Add function to enable core 1 for BF609 and BF561.
Add config macro to allow customer to run core 1 in uboot init code on core 0.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Newer gcc versions will sometimes use a Preg when "r" constraints, but
that'll fail if we use an Ireg in the assignment. So force the code
to always use a Dreg.
This also fixes early boot crashes for older Blackfin parts when compiled
with gcc-4.5. This version ends up selecting the same register for the
input and output variables which corrupts the output assignment triggering
an exception.
P2 = 0xffe02008; /* EVT2 */
R0 = RETS;
CALL 1f;
RTN;
1: P2 = RETS; <-- BAD
RETS = R0;
[P2] = P2; <-- BAD
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Add support for following features:
- nand boot, with PMECC 2bit ECC for 512 bytes sector
- SPI flash boot
- SD card boot
- LCD support
Signed-off-by: Josh Wu <josh.wu@atmel.com>
[fix -Wimplicit-function-declaration for at91_lcd_hw_init()]
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
Since at91sam9n12 is a subset of at91sam9x5, so put all at91sam9n12
definitions in at91sam9x5 head file.
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
The boot parameters passed from SPL to UBOOT
must be saved as a part of uboot's gd data
as early as possible, before we will inadvertently
overwrite it. So adding a arch_cpu_init for the required
Socs to save it.
Signed-off-by: Sricharan R <r.sricharan@ti.com>
[trini: Add igep0033 hunk]
Signed-off-by: Tom Rini <trini@ti.com>
The boot parameters are read from individual variables
assigned for each of them. This been corrected and now
they are stored as a part of the global data 'gd'
structure. So read them from 'gd' instead.
Signed-off-by: Sricharan R <r.sricharan@ti.com>
[trini: Add igep0033 hunk]
Signed-off-by: Tom Rini <trini@ti.com>
Currently save_boot_params saves the boot parameters passed
from romcode. But this is not stored in a writable location
consistently. So the current code would not work for a
'XIP' boot. Change this by saving the boot parameters in
'gd' which is always writable. Also add a 'C' function
instead of an assembly code that is more readable.
Signed-off-by: Sricharan R <r.sricharan@ti.com>
These defines are same across OMAP4/5. So move them to
omap_common.h. This is required for the patches that
follow.
Signed-off-by: Sricharan R <r.sricharan@ti.com>
omap_boot_parameters is same and defined for each
soc. So move this to a common place to reuse it
across socs.
Signed-off-by: Sricharan R <r.sricharan@ti.com>
The arm_freq and ddr_freq variables are unused, so remove. Fixup
whitespace slightly while in here.
Reviewed-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Tom Rini <trini@ti.com>
these variables are curently defined in several config files but the
driver doesn't use them and defaults to hardcoded values in
nand_defs.h
It's interesting to be able to change this hardcoded valude when the
hardware is not using the default adress signals to drive ALE and CLE
and two configuration defines already exist for this purpose so use
them.
Signed-off-by: Eric Bénard <eric@eukrea.com>
this is needed to bring UART0 out of reset but this function
currently only exists for dm644x/355/365/646x when da850 (at
least am1808 also need it).
Signed-off-by: Eric Bénard <eric@eukrea.com>
Warm reset on OMAP5 freezes when USB cable is connected.
Fix requires PRM_RSTTIME.RSTTIME1 to be programmed
with the time for which reset should be held low for the
voltages and the oscillator to reach stable state.
There are 3 parameters to be considered for calculating
the time, which are mostly board and PMIC dependent.
-1- Time taken by the Oscillator to shut + restart
-2- PMIC OTP times
-3- Voltage rail ramp times, which inturn depends on the
PMIC slew rate and value of the voltage ramp needed.
In order to keep the code in u-boot simple, have a way
for boards to specify a pre computed time directly using
the 'CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC'
option. If boards fail to specify the time, use a default
as specified by 'CONFIG_DEFAULT_OMAP_RESET_TIME_MAX_USEC' instead.
Using the default value translates into some ~22ms and should work in
all cases.
However in order to avoid this large delay hiding other bugs,
its recommended that all boards look at their respective data
sheets and specify a pre computed and optimal value using
'CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC'
In order to help future board additions to compute this
config option value, add a README at doc/README.omap-reset-time
which explains how to compute the value. Also update the toplevel
README with the additional option and pointers to
doc/README.omap-reset-time.
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
[rnayak@ti.com: Updated changelog and added the README]
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
USB TLL clocks do not support 'explicit_en', only 'hw_auto'
control (R. Sricharan). cm_l3init_hsusbtll_clkctrl has to be
moved to the clk_modules_hw_auto_essential[] array in order
to make the clock work.
This fix is needed (but not sufficient) for USB EHCI operation
in U-Boot.
Signed-off-by: Lubomir Popov <lpopov@mm-sol.com>
EMIF supports a global warm reset mode, during which the
EMIF keeps the SDRAM content. But if leveling is enabled
at the time of warm reset for DDR3, the following steps
needs to be done after warm reset:
1) Keep EMIF in self refresh mode.
2) Reset PHY to bring back the PHY to a known state.
3) Start Levelling procedure.
Doing the same.
And also enabling DLL lock and code output after warm reset.
Tested on OMAP5432 ES2.0
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
I2C4 and I2C5 are utilized on all known OMAP5 hardware platforms.
In order to be able to select one of these buses however, I2C_BUS_MAX
has to be set to 5; do this here.
Please note that for working bus selection, a fix to the i2c driver
is required as well (subject of a separate patch).
Signed-off-by: Lubomir Popov <lpopov@mm-sol.com>
I2C4 and I2C5 are utilized on all known OMAP5 hardware platforms.
The I2C4 and I2C5 base addresses were however not defined; do this
here.
Signed-off-by: Lubomir Popov <lpopov@mm-sol.com>
I2C4 and I2C5 are utilized on all known OMAP5 hardware platforms.
The i2c5 clock was however not enabled; do this here.
Signed-off-by: Lubomir Popov <lpopov@mm-sol.com>
Microblaze uses gpio which is connected to the system reset.
Currently gpio subsystem wasn't used for it.
Add gpio driver and change Microblaze reset logic to be done
via gpio subsystem.
There are various configurations which Microblaze can have
that's why gpio_alloc/gpio_alloc_dual(for dual channel)
function has been introduced and gpio can be allocated
dynamically.
Adding several gpios IP is also possible and supported.
For listing gpio configuration please use "gpio status" command
This patch also remove one compilation warning:
microblaze-generic.c: In function 'do_reset':
microblaze-generic.c:38:47: warning: operation on '*1073741824u'
may be undefined [-Wsequence-point]
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
fdt_initrd add additional information to DTB about initrd
addresses which are later used by kernel.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Include this header to get access to link symbols, which are otherwise
removed.
Signed-off-by: Kuan-Yu Kuo <ken.kuoky@gmail.com>
Cc: Macpaul Lin <macpaul@gmail.com>
Extend the regs-lcdif.h with registers for i.MX233.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Stefano Babic <sbabic@denx.de>
This function turns on the LCDIF clock and configures it's frequency. The
dividers settings are calculated within the function and the current
implementation should be fast and accurate.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Stefano Babic <sbabic@denx.de>
Devcfg device requires to load bitstream in binary format.
But u-boot also has an option for loading bitstream in bit
format. Let's handle both cases by zynqpl driver.
Also add suport for loading partial bitstreams.
The first driver version was done by:
Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Tom Rini <trini@ti.com>
The u-boot-imx23.bd and u-boot-imx28.bd need to be preprocessed, otherwise
they have issues with out-of-tree build where elftosb tool couldn't sometimes
find the u-boot.bin and spl/u-boot-spl.bin .
Preprocess these .bd files with sed and insert full path to u-boot.bin and
spl/u-boot-spl.bin to prevent this issue. Moreover, to avoid adding more
churn into main Makefile, move all this preprocessing and u-boot.sb generation
into CPU directory instead.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Stefano Babic <sbabic@denx.de>
Acked-by: Otavio Salvador <otavio@ossystems.com.br>
The VDDMEM ramped up in very weird way as it was horribly misconfigured.
Instead of setting up VDDMEM in one swipe, let it rise slowly the same
way as VDDD and VDDA in spl_power_init.c and then only clear ILIMIT before
memory gets inited. This makes sure the VDDMEM rises sanely, not jumps up
and down as it did till now.
The VDDMEM prior to this change did this:
2V0____ .--------2V5
| `--'
0V____|
The VDDMEM now does this:
2V0_____,-----------2V5
/
0V__|
Moreover, VDDIO on MX23 uses 25mV steps while MX28 uses 50mV steps,
fix this difference too.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Stefano Babic <sbabic@denx.de>
Put an explanation in the source code as to why some DDR registers do not
need to be configured.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
