Add support of Renesas R-Car Gen5 window watchdog timer. Timeout
configuration is derived from CONFIG_WATCHDOG_TIMEOUT_MSECS, which
is more accurate than the 1-second granularity 'timeout' passed to
.start callback.
Reviewed-by: Stefan Roese <stefan.roese@mailbox.org>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
The U_BOOT_DRIVER macro creates a list of drivers used at link time, and
all entries here must be unique. This in turn means that all entries in
the code should also be unique in order to not lead to build failures
later with unexpected build combinations. Typically, the problem we have
here is when a driver is obviously based on another driver and didn't
update this particular field and so while the name field reflects
something unique the linker entry itself is not. In a few places this
provides a more suitable string name as well, however.
Reviewed-by: Marek Vasut <marek.vasut+usb@mailbox.org>
Reviewed-by: Svyatoslav Ryhel <clamor95@gmail.com> # Tegra
Reviewed-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Heiko Schocher <hs@nabladev.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
Prevent the Qualcomm watchdog from autostarting and ensure it's stopped
when the driver probed. In some cases the watchdog is left running by
a previous bootloader stage. Disable autostart so it isn't left running
when we boot into the OS, this behaviour can be changed by enabling
autostart in the board defconfig.
Reviewed-by: Stefan Roese <stefan.roese@mailbox.org>
Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Link: https://patch.msgid.link/20260121003659.69305-1-casey.connolly@linaro.org
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>
After years of developing the ADI ADSP platform, Timesys was purchased
by another company and is no longer contracted to maintain the platform.
Signed-off-by: Philip Molloy <philip.molloy@analog.com>
Reviewed-by: Greg Malysa <malysagreg@gmail.com>
Julien Stephan <jstephan@baylibre.com> says:
This series adds basic support for Mediatek soc MT8195:
- clock driver
- watchdog
- add a new macro helper to define gate clock. Other driver can be
cleaned later to use the new macro
Other driver will be added later.
It will also serve as basis for board support such as MT8395_EVK based
on MT8195.
Link: https://lore.kernel.org/r/20260202-add-mt8195-clock-support-v1-0-5d03495246b9@baylibre.com
This adds basic support for MediaTek MT8195 SoC.
Add watchdog support by adding upstream compatible string.
Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Remove DECLARE_GLOBAL_DATA_PTR from files where gd is not used, and
drop the unnecessary inclusion of asm/global_data.h.
Headers should be included directly by the files that need them,
rather than indirectly via global_data.h.
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com> #STMicroelectronics boards and STM32MP1 ram test driver
Tested-by: Anshul Dalal <anshuld@ti.com> #TI boards
Acked-by: Yao Zi <me@ziyao.cc> #TH1520
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Added a check to ensure the requested timeout does not exceed the
hardware's maximum supported value. This prevents register overflow
and ensures watchdog reliability.
So, added a check in qcom_wdt_start() to ensure the requested timeout
does not exceed the hardware-supported maximum value. If the requested
value exceeds the maximum value, then the timeout is clamped
at maximum value.
The timeout is first converted to watchdog ticks and then compared
against QCOM_WDT_MAX_TIMEOUT. This helps prevent misconfiguration
and potential watchdog misbehavior due to overflow.
QCOM_WDT_MAX_TIMEOUT is set to 0xFFFFF, as Qualcomm SoCs typically
use 20 bits to store bark/bite timeout values.
This work builds upon the previous submission:
https://lore.kernel.org/u-boot/20250527124926.128413-1-balaji.selvanathan@oss.qualcomm.com/
Signed-off-by: Gopinath Sekar <gopinath.sekar@oss.qualcomm.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Link: https://patch.msgid.link/20250625094607.1348494-1-gopinath.sekar@oss.qualcomm.com
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>
Julien Stephan <jstephan@baylibre.com> says:
The MediaTek MT8188 is a ARM64-based SoC with a dual-core Cortex-A78
cluster and a six-core Cortex-A55 cluster. It includes UART, SPI,
USB3.0 dual role, SD and MMC cards, UFS, PWM, I2C, I2S, S/PDIF, and
several LPDDR3 and LPDDR4 options.
This series adds basic support for MT8188.
Link: https://lore.kernel.org/r/20251209-add-mt8188-support-v2-0-31dbfcf7303c@baylibre.com
This adds basic support for MediaTek MT8188 SoC.
Add watchdog support by adding upstream compatible string.
Add tphy support by adding "mediatek,generic-tphy-v2" compatible string
in arch/arm/dts/mt8188-u-boot.dtsi
Signed-off-by: Julien Masson <jmasson@baylibre.com>
Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
Reviewed-by: Macpaul Lin <macpaul.lin@mediatek.com>
Provide support for Tegra watchdog functionality. The WATCHDOG index 0 in
conjunction with TIMER 5 is used inline with existing Linux kernel driver.
Signed-off-by: Lukasz Majewski <lukma@nabladev.com>
Reviewed-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
The WDT_DAVINCI driver is not safe to compile on 64bit platforms such as
allyesconfig on a 64bit host. Tighten the dependencies here to the
platforms which could use it today.
Signed-off-by: Tom Rini <trini@konsulko.com>
A few watchdog drivers cannot build without access to some platform
specific header files. Express those requirements in Kconfig as well.
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Stefan Roese <stefan.roese@mailbox.org>
Enable watchdog as early as possible after clock initialization
which is set at 10 seconds.
Signed-off-by: Alif Zakuan Yuslaimi <alif.zakuan.yuslaimi@altera.com>
Reviewed-by: Tien Fong Chee <tien.fong.chee@altera.com>
On STM32MP reference boards, the watchdog is started by a previous
boot stage (e.g. bootrom or secure OS), so the config flag
WATCHDOG_AUTOSTART is not required.
It's preferable to rely on the DT properties "u-boot,autostart" or
"u-boot,noautostart", if needed.
For backward compatibility on defconfigs that are based on SPL,
thus cannot rely on a previous boot stage for starting the
watchdog, enable WATCHDOG_AUTOSTART in their respective defconfig.
The change in stm32mp15_dhsom.config is propagated to:
- configs/stm32mp15_dhcom_basic.config
- configs/stm32mp15_dhcor_basic.config
and then to:
- stm32mp15_dhcom_basic_defconfig
- stm32mp15_dhcom_drc02_basic_defconfig
- stm32mp15_dhcom_pdk2_basic_defconfig
- stm32mp15_dhcom_picoitx_basic_defconfig
- stm32mp15_dhcor_avenger96_basic_defconfig
- stm32mp15_dhcor_basic_defconfig
- stm32mp15_dhcor_drc_compact_basic_defconfig
- stm32mp15_dhcor_testbench_basic_defconfig
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Add a mean to check the IWDG status based on the peripheral version.
This is done by either checking the status bit ONF either by updating
the reload register with the same value and check if the reload succeed.
Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
The optional SMCWD_GET_TIMELEFT command can be used to detect if
the watchdog has already been started.
See the implementation in OP-TEE secure OS [1].
At probe time, check if the watchdog is already started and then
call wdt_set_force_autostart(). This will keep U-Boot pinging the
watchdog even when the property 'u-boot,noautostart' is present.
Link: https://github.com/OP-TEE/optee_os/commit/a7f2d4bd8632 [1]
Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
The watchdog could have been already started by a previous boot
stage (e.g. bootrom or secure OS). U-Boot has to start and kick
the watchdog even when CONFIG_WATCHDOG_AUTOSTART is not enabled
or when the DT property u-boot,noautostart is present.
Add the helper wdt_set_force_autostart() that can be called by the
driver's probe() when it detects that the watchdog has already
been started and is running.
Co-developed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
On some Qualcomm platforms, such as Dragonwing boards, the WDT_EN
register is write-only. Reading it back after enabling the watchdog
can return invalid data or cause unexpected behavior.
In particular, the check:
if (readl(wdt_addr(wdt, WDT_EN)) != 1)
may fail even though the watchdog is correctly enabled and running.
This leads to misleading error messages and unnecessary failures.
Removing the read check ensures compatibility and avoids false
negatives on platforms where WDT_EN is not readable.
This work builds upon this previous submission:
https://lore.kernel.org/u-boot/20250625094607.1348494-1-gopinath.sekar@oss.qualcomm.com/
Signed-off-by: Balaji Selvanathan <balaji.selvanathan@oss.qualcomm.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Link: https://lore.kernel.org/r/20250701065738.1644669-1-balaji.selvanathan@oss.qualcomm.com
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>
With the removal of the last i.MX31 platform we can remove the rest of
the underlying architecture code as well.
Fixes: f247354708ec ("arm: Remove mx31pdk board")
Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Peng Fan <peng.fan@nxp.com>
This patch enhances the Qualcomm watchdog driver by introducing
support for dynamic timeout configuration. Specifically:
- Calculates and sets the bark and bite timeout values based on
the clock rate and the requested timeout in milliseconds.
- Adds retrieval of the watchdog clock rate during probe using
the common clock framework.
- Adds a default timeout value for ARCH_SNAPDRAGON
in WATCHDOG_TIMEOUT_MSECS.
These changes improve the configurability and accuracy of the
watchdog timer on Qualcomm platforms.
This work builds upon the previous submission:
https://lore.kernel.org/all/20250422-b4-qcom-wdt-v3-1-730d4d5a858d@paulsajna.com/
Signed-off-by: Balaji Selvanathan <balaji.selvanathan@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250527124926.128413-1-balaji.selvanathan@oss.qualcomm.com
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>
Some Qualcomm device vendors decide to turn the watchdog on in the
bootloader, resulting in the device being reset if it isn't petted every
~30 seconds. Introduce a driver to keep the watchdog happy and prevent this
annoying behaviour.
Signed-off-by: Paul Sajna <hello@paulsajna.com>
Co-authored-by: Paul Sajna <hello@paulsajna.com>
Tested-by: Paul Sajna <hello@paulsajna.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Acked-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250422-b4-qcom-wdt-v3-1-730d4d5a858d@paulsajna.com
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>
-----BEGIN PGP SIGNATURE-----
iQFNBAABCgA3FiEEqxhEmNJ6d7ZdeFLIHrMeAg6sL8gFAmhT7U8ZHGV1Z2VuLmhy
aXN0ZXZAbGluYXJvLm9yZwAKCRAesx4CDqwvyLtkB/9PD1rYJMwwPx0YXb2Wb0tw
VTElDjAjmth6wFwnJMHzD+QDNJYz6cRhDcMBTuDd+LEYONEE9J+nfI9w64WfPTqb
5cJ2TVzQZKwMds8OVFitjs7FI+YM4KjzmHC4ts4TAgIz6zKnkjsxUGM8yH7ci9If
oIfBbLrK9SibthWOXAN0m6QE6StuAdvjERfuTOXTZw44W3eXPMEI7fV0USspw4Ic
T49Yj6mR4jnAFdvfqqUr6RoKWTTyvrecA15405l8hauHFG88t40zufsHlpABkY8D
6pr5bNP90g6bXkd4GM/D1Vq59nhc4tdSP/imb6s2QWfuHhFnBSpJfHpZl4G0i6tU
=sxcV
-----END PGP SIGNATURE-----
Merge tag 'u-boot-at91-2025.10-a' of https://source.denx.de/u-boot/custodians/u-boot-at91 into next
First set of u-boot-at91 features for the 2025.10 cycle:
This feature set includes the addition of new sam9x7 SoC and a new board
named sam9x7-curiosity. There is also new support for sam9x60 compatible
at91 watchdog.
SAM9X60 has a slightly different watchdog implementation:
- Timer value moved into a new register WLR
- Some MR register fields have their position changed
This patch add SAM9X60 support, also adds a compatible
for SAMA5D4 which is the same as existing SAM9260.
Signed-off-by: Zixun LI <admin@hifiphile.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Add support of Renesas R-Car Gen4 watchdog timer. Timeouts up to
8184.0s are supported (CKS1 register is not involved). The watchdog
uses the clock of type CLK_TYPE_GEN4_MDSEL.
The timeout is set in
dts/upstream/src/arm64/renesas/r8a779f0-spider-cpu.dtsi section &rwdt.
This driver is based on upstream linux commit:
e70140ba0d2b("Get rid of 'remove_new' relic from platform driver struct")
Signed-off-by: Shmuel Leib Melamud <smelamud@redhat.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
The Allwinner A523 SoC moved the watchdog into a separate MMIO frame,
and also shifted the registers a bit: the control, config, and mode
register are located four bytes earlier.
Add the new compatible string, and connect it to the new struct
describing the new register layout.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Some drivers set DM_FLAG_PROBE_AFTER_BIND, this does nothing since it's
only every applied on a per-device basis.
Remove the flags.
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Michal Simek <michal.simek@amd.com>
The hack itself seems to be copied from Linux rti_wdt.c, but the WDT reset
principle is different in U-Boot. While Linux relies on correct frequencies
and timers and doesn't check the actual WDT counter value U-Boot driver
seems to be more robust: it does compare RTIDWDCNTR vs RTIDWDPRLD.
Now the root cause of the original motivation to manipulate the clock rate
is said to be understood and fixed in Linux commit cae58516534e
("watchdog: rti_wdt: Set min_hw_heartbeat_ms to accommodate a safety margin")
which simultaneously removed the hack itself.
While is fix part of the mentioned patch is neither applicable nor requried
for the U-Boot driver just drop the hack setting WDT clock rate to 90% of
the real rate. This has a nice effect that the WDT timeout is now as
requested and not 10% shorter.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Stefan Roese <sr@denx.de>
If the RTI watchdog has been enabled in SPL, enabling it in U-Boot proper
fails because it can only be enabled once in HW and never stopped. This
however leads to a situation that wdt_cyclic() watchdog trigger is not
being started any longer and the WDT fires at some point.
Allow for WDT re-start by not bailing out if the [previously] configured
period matches the one to be configured.
Enabling in [A53] SPL has been tested on AM62x-based HW (where [A53] SPL is
responsible for loading R5 DM firmware and not this driver).
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Driver for a PMIC watchdog timer controlled via Siemens SCU firmware
extensions. Only useful on some Siemens i.MX8-based platforms as
special SCFW is needed which provides the needed SCU API.
Signed-off-by: Andrej Valek <andrej.valek@siemens.com>
Signed-off-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Currently, enabling WDT_GPIO on a board which uses SPL, but does not
have SPL_WDT, SPL_DM_GPIO or SPL_OF_CONTROL enabled, breaks the build.
Make it possible to use the WDT_GPIO driver on such boards by
introducing a separate symbol controlling whether the driver is built
for SPL. Make it default to WDT_GPIO such that boards that already
have it enabled and all the SPL prerequisites satisfied will continue
to have it in SPL.
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Back when I added this driver in commit 2ac8490412c9, I wrote
The corresponding linux driver apparently has support for some
watchdog circuits which can be disabled by tri-stating the gpio, but I
have never actually encountered such a chip in the wild;
That has changed now; I have a board with just such a watchdog on my
desk currently. Add support for that.
- For a hw_algo="toggle" device, the gpio is requested as output if the
always-running flag is set, otherwise as input.
- The ->start() method is updated to change the direction to output when
required (i.e. it is not always-running).
- The ->stop() method is implemented, but of course reports failure if
always-running.
As I still haven't met any hw_algo="level" devices, I'm not entirely
sure how they fit in, but I'm borrowing logic from the corresponding
linux driver:
- In ->probe(), such devices always request the gpio as GPIOD_IS_OUT.
- In ->stop(), the linux driver has an "eternal ping" comment and sets
the gpio to (logic) high.
Stefan:
Added necessary changes in test/dm/wdt.c to fix CI build breakage, as
suggested by Rasmus.
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
Reviewed-by: Stefan Roese <sr@denx.de>
Simon Glass <sjg@chromium.org> says:
When the SPL build-phase was first created it was designed to solve a
particular problem (the need to init SDRAM so that U-Boot proper could
be loaded). It has since expanded to become an important part of U-Boot,
with three phases now present: TPL, VPL and SPL
Due to this history, the term 'SPL' is used to mean both a particular
phase (the one before U-Boot proper) and all the non-proper phases.
This has become confusing.
For a similar reason CONFIG_SPL_BUILD is set to 'y' for all 'SPL'
phases, not just SPL. So code which can only be compiled for actual SPL,
for example, must use something like this:
#if defined(CONFIG_SPL_BUILD) && !defined(CONFIG_TPL_BUILD)
In Makefiles we have similar issues. SPL_ has been used as a variable
which expands to either SPL_ or nothing, to chose between options like
CONFIG_BLK and CONFIG_SPL_BLK. When TPL appeared, a new SPL_TPL variable
was created which expanded to 'SPL_', 'TPL_' or nothing. Later it was
updated to support 'VPL_' as well.
This series starts a change in terminology and usage to resolve the
above issues:
- The word 'xPL' is used instead of 'SPL' to mean a non-proper build
- A new CONFIG_XPL_BUILD define indicates that the current build is an
'xPL' build
- The existing CONFIG_SPL_BUILD is changed to mean SPL; it is not now
defined for TPL and VPL phases
- The existing SPL_ Makefile variable is renamed to SPL_
- The existing SPL_TPL Makefile variable is renamed to PHASE_
It should be noted that xpl_phase() can generally be used instead of
the above CONFIGs without a code-space or run-time penalty.
This series does not attempt to convert all of U-Boot to use this new
terminology but it makes a start. In particular, renaming spl.h and
common/spl seems like a bridge too far at this point.
The series is fully bisectable. It has also been checked to ensure there
are no code-size changes on any commit.
Use PHASE_ as the symbol to select a particular XPL build. This means
that SPL_TPL_ is no-longer set.
Update the comment in bootstage to refer to this symbol, instead of
SPL_
Signed-off-by: Simon Glass <sjg@chromium.org>
The DA9063 PMIC is a multi-function device that provides
regulator, watchdog, RTC, and ON key functionalities.
Add support for the DA9063 PMIC watchdog functionality.
Based on the 6.11 kernel drivers/watchdog/da9063_wdt.c driver.
Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Stefan Roese <sr@denx.de>
The cyclic subsystem is currently enabled either in all build phases
or none. For tools this should not be enabled, but since lib/shc256.c
and other files include watchdog.h in the host build, we must make
sure that it is not enabled there.
Add an SPL symbol so that there is more control of this.
Add an include into cyclic.h so that tools can include this file.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Devarsh Thakkar <devarsht@ti.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Timer value is a 16 bits calculated from the wanted timeout and the
system clock. On powerpc/8xx, a timeout of 2s gives a value which
is over U16_MAX so U16_MAX shall be used. But the calculation is
casted to u16 so at the end the result is 63770 instead of 128906.
So the timer gets loaded with 63770 instead of 65535. It is not
a big difference in that case, but lets make the code correct and
cast to u32 instead of u16.
Fixes: 26e8ebcd7cb7 ("watchdog: mpc8xxx: Make it generic")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
watchdog_reset() is no longer called from anywhere, so we do not need
to define a dummy no-op function. Remove that definition, and update
references to say schedule() instead.
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Stefan Roese <sr@denx.de>
There are of course not a whole lot of examples in-tree yet, but
before they appear, let's make this API change: Instead of separately
allocating a 'struct cyclic_info', make the users embed such an
instance in their own structure, and make the convention that the
callback simply receives the 'struct cyclic_info *', from which the
clients can get their own data using the container_of() macro.
This has a number of advantages.
First, it means cyclic_register() simply cannot fail, simplifying the
code. The necessary storage will simply be allocated automatically
when the client's own structure is allocated (often via
uclass_priv_auto or similar).
Second, code for which CONFIG_CYCLIC is just an option can more easily
be written without #ifdefs, if we just provide an empty struct
cyclic_info {}. For example, the nested CONFIG_IS_ENABLED()s in
https://lore.kernel.org/u-boot/20240316201416.211480-1-marek.vasut+renesas@mailbox.org/
are mostly due to the existence of the 'struct cyclic_info *' member
being guarded by #ifdef CONFIG_CYCLIC.
And we do probably want to avoid the extra memory overhead of that
member when !CONFIG_CYCLIC. But that is automatic if, instead of a
'struct cyclic_info *', one simply embeds a 'struct cyclic_info',
which will have size 0 when !CONFIG_CYCLIC. Also, the no-op
cyclic_register() function can just unconditionally be called, and the
compiler will see that (1) the callback is referenced, so not emit a
warning for a maybe-unused function and (2) see that it can actually
never be reached, so not emit any code for it.
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
