Card write threshold control is supposed to be set since controller
version 2.80a for data write in HS400 mode and data read in
HS200/HS400/SDR104 mode. However the current code returns without
configuring it in the case of data writing in HS400 mode.
Meanwhile the patch fixes that the current code goes to
'disable' when doing data reading in HS400 mode.

Fixes: 7e4bf1bc ("mmc: dw_mmc: add the card write threshold for HS400 mode")
Signed-off-by: NQing Xia <xiaqing17@hisilicon.com>
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Respect the actual clock for mmc debugfs to help better debug
the hardware.

mmc_host mmc0: Bus speed (slot 0) = 135475200Hz (slot req 150000000Hz,
actual 135475200HZ div = 0)

cat /sys/kernel/debug/mmc0/ios
clock:          150000000 Hz
actual clock:   135475200 Hz
vdd:            21 (3.3 ~ 3.4 V)
bus mode:       2 (push-pull)
chip select:    0 (don't care)
power mode:     2 (on)
bus width:      3 (8 bits)
timing spec:    9 (mmc HS200)
signal voltage: 0 (1.80 V)
driver type:    0 (driver type B)

Cc: Xiao Yao <xiaoyao@rock-chips.com>
Cc: Ziyuan <xzy.xu@rock-chips.com>
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

It was found that in IDMAC mode after soft-reset driver switches
to PIO mode.

That's what happens in case of DTO timeout overflow calculation failure:
1. soft-reset is called
2. driver restarts dma
3. descriptors states are checked, one of descriptor is owned by the IDMAC.
4. driver can't use DMA and then switches to PIO mode.

Failure was already fixed in:
https://www.spinics.net/lists/linux-mmc/msg48125.html.

Behaviour while soft-reset is not something we except or
even want to happen. So we switch from dw_mci_idmac_reset
to dw_mci_idmac_init, so descriptors are cleaned before starting dma.

And while at it explicitly zero des0 which otherwise might
contain garbage as being allocated by dmam_alloc_coherent().
Signed-off-by: NEvgeniy Didin <Evgeniy.Didin@synopsys.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Cc: Shawn Lin <shawn.lin@rock-chips.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: <stable@vger.kernel.org> # 4.4+
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

'num-slots' property had already deprecated.
Remove the 'nom-slots' property that is kept to maintain the compatibility.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

'clock-freq-min-max' property had already deprecated.
Remove the 'clock-freq-min-max' property that is kept to maintain
the compatibility.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Clang reports a compile warning:
drivers/mmc/host/dw_mmc.c:2124:5: warning: Value stored to 'prev_state'
is never read

By checking the code, prev_state and state assignment for
STATE_SENDING_CMD is indeed never used after jumping to unlock tag.
So remove it.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Use the newly added macro to simply to the code.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

The commit 9d9491a7 ("mmc: dw_mmc: Fix the DTO timeout calculation")
and commit 4c2357f5 ("mmc: dw_mmc: Fix the CTO timeout calculation")
made changes, which cause multiply overflow for 32-bit systems. The broken
timeout calculations leads to unexpected ETIMEDOUT errors and causes
stacktrace splat (such as below) during normal data exchange with SD-card.

| Running :  4M-check-reassembly-tcp-cmykw2-rotatew2.out -v0 -w1
| -  Info: Finished target initialization.
| mmcblk0: error -110 transferring data, sector 320544, nr 2048, cmd
| response 0x900, card status 0x0

DIV_ROUND_UP_ULL helps to escape usage of __udivdi3() from libgcc and so
code gets compiled on all 32-bit platforms as opposed to usage of
DIV_ROUND_UP when we may only compile stuff on a very few arches.

Lets cast this multiply to u64 type to prevent the overflow.

Fixes: 9d9491a7 ("mmc: dw_mmc: Fix the DTO timeout calculation")
Fixes: 4c2357f5 ("mmc: dw_mmc: Fix the CTO timeout calculation")
Tested-by: NVineet Gupta <Vineet.Gupta1@synopsys.com>
Reported-by: Vineet Gupta <Vineet.Gupta1@synopsys.com> # ARC STAR 9001306872 HSDK, sdio: board crashes when copying big files
Signed-off-by: NEvgeniy Didin <Evgeniy.Didin@synopsys.com>
Cc: <stable@vger.kernel.org> # 4.14
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: NJisheng Zhang <Jisheng.Zhang@synaptics.com>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

cat /sys/kernel/debug/mmc0/regs will hang up the system since
it's in runtime suspended state, so the genpd and biu_clk is
off. This patch fixes this problem by calling pm_runtime_get_sync
to wake it up before reading the registers.

Fixes: e9ed8835 ("mmc: dw_mmc: add runtime PM callback")
Cc: <stable@vger.kernel.org>
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Add num_caps field for dw_mci_drv_data to validate the controller
id from DT alias and non-DT ways.
Reported-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Fixes: 800d78bf ("mmc: dw_mmc: add support for implementation specific callbacks")
Cc: <stable@vger.kernel.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Factor out dw_mci_init_slot_caps to consolidate parsing
all differents types of capabilities from host contrllers.
No functional change intended.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Fixes: 800d78bf ("mmc: dw_mmc: add support for implementation specific callbacks")
Cc: <stable@vger.kernel.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: linux-mmc@vger.kernel.org
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

The recent CTO timer introduced in commit 03de1921 ("mmc: dw_mmc:
introduce timer for broken command transfer over scheme") was causing
observable problems due to race conditions.  Previous patches have
fixed those race conditions.

It can be observed that these same race conditions ought to be
theoretically possible with the DTO timer too though they are
massively less likely to happen because the data timeout is always set
to 0xffffff right now.  That means even at a 200 MHz card clock we
were arming the DTO timer for 94 ms:
  >>> (0xffffff * 1000. / 200000000) + 10
  93.886075

We always also were setting the DTO timer _after_ starting the
transfer, unlike how the old code was seting the CTO timer.

In any case, even though the DTO timer is much less likely to have
races, it still makes sense to add code to handle it _just in case_.
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Just like the CTO timeout calculation introduced recently, the DTO
timeout calculation was incorrect.  It used "bus_hz" but, as far as I
can tell, it's supposed to use the card clock.  Let's account for the
div value, which is documented as 2x the value stored in the register,
or 1 if the register is 0.

NOTE: This was likely not terribly important until commit 16a34574
("mmc: dw_mmc: remove the quirks flags") landed because "DIV" is
documented on Rockchip SoCs (the ones that used to define the quirk)
to always be 0 or 1.  ...and, in fact, it's documented to only be 1
with EMMC in 8-bit DDR52 mode.  Thus before the quirk was applied to
everyone it was mostly OK to ignore the DIV value.

I haven't personally observed any problems that are fixed by this
patch but I also haven't tested this anywhere with a DIV other an 0.
AKA: this problem was found simply by code inspection and I have no
failing test cases that are fixed by it.  Presumably this could fix
real bugs for someone out there, though.

Fixes: 16a34574 ("mmc: dw_mmc: remove the quirks flags")
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

This attempts to instill a bit of paranoia to the code dealing with
the CTO timer.  It's believed that this will make the CTO timer more
robust in the case that we're having very long interrupt latencies.

Note that I originally thought that perhaps this patch was being
overly paranoid and wasn't really needed, but then while I was running
mmc_test on an rk3399 board I saw one instance of the message:
  dwmmc_rockchip fe320000.dwmmc: Unexpected interrupt latency

I had debug prints in the CTO timer code and I found that it was
running CMD 13 at the time.

...so even though this patch seems like it might be overly paranoid,
maybe it really isn't?

Presumably the bad interrupt latency experienced was due to the fact
that I had serial console enabled as serial console is typically where
I place blame when I see absurdly large interrupt latencies.  In this
particular case there was an (unrelated) printout to the serial
console just before I saw the "Unexpected interrupt latency" printout.

...and actually, I managed to even reproduce the problems by running
"iw mlan0 scan > /dev/null" while mmc_test was running.  That not only
does a bunch of PCIe traffic but it also (on my system) outputs some
SELinux log spam.

Fixes: 03de1921 ("mmc: dw_mmc: introduce timer for broken command transfer over scheme")
Tested-by: NEmil Renner Berthing <kernel@esmil.dk>
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

In the commit 03de1921 ("mmc: dw_mmc: introduce timer for broken
command transfer over scheme") we tried to calculate the expected
hardware command timeout value.  Unfortunately that calculation isn't
quite correct in all cases.  It used "bus_hz" but, as far as I can
tell, it's supposed to use the card clock.  Let's account for the div
value, which is documented as 2x the value stored in the register, or
1 if the register is 0.

NOTE: It's not expected that this will actually fix anything important
since the 10 ms margin added by the function will pretty much dwarf
any calculations.  The card clock should be 100 kHz at minimum and:
  1000 ms/s * (255 * 2) / 100000 Hz.
Gives us 5.1 ms.

...so really the point of this patch is just to make the code more
"correct" in case anyone ever tries to remove the 10 ms buffer.

Fixes: 03de1921 ("mmc: dw_mmc: introduce timer for broken command transfer over scheme")
Tested-by: NEmil Renner Berthing <kernel@esmil.dk>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

When running with the commit 03de1921 ("mmc: dw_mmc: introduce
timer for broken command transfer over scheme") I found this message
in the log:
  Unexpected command timeout, state 7

It turns out that we weren't properly cancelling the new CTO timer in
the case that a voltage switch was done.  Let's promote the cancel
into the dw_mci_cmd_interrupt() function to fix this.

Fixes: 03de1921 ("mmc: dw_mmc: introduce timer for broken command transfer over scheme")
Tested-by: NEmil Renner Berthing <kernel@esmil.dk>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Bail out everytime when mmc_regulator_get_supply() returns an errno, not
only when probing gets deferred. This is currently a no-op, because this
function only returns -EPROBE_DEFER or 0 right now. But if it will throw
another error somewhen, it will be for a reason. (This still doesn't change
that getting regulators is optional, so 0 can still mean no regulators
found). So, let us a) be future proof and b) have driver code which is
easier to understand.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Don't populate the const arrays mszs on the stack, instead make them
static. Makes the object code smaller by over 310 bytes:

Before:
   text	   data	    bss	    dec	    hex	filename
  47527	   8528	    320	  56375	   dc37	drivers/mmc/host/dw_mmc.o

After:
   text	   data	    bss	    dec	    hex	filename
  47055	   8688	    320	  56063	   daff	drivers/mmc/host/dw_mmc.o
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Per the databook of designware mmc controller 2.70a, table 3-2, cmd
done interrupt should be fired as soon as the the cmd is sent via
cmd line. And the response timeout interrupt should be generated
unconditioinally as well if the controller doesn't receive the resp.
However that doesn't seem to meet the fact of rockchip specified Soc
platforms using dwmmc. We have continuously found the the cmd done or
response timeout interrupt missed somehow which took us a long time to
understand what was happening. Finally we narrow down the root to
the reconstruction of sample circuit for dwmmc IP introduced by
rockchip and the buggy design sweeps over all the existing rockchip
Socs using dwmmc disastrously.

It seems no way to work around this bug without the proper break-out
mechanism so that we seek for a parallel pair the same as the handling
for missing data response timeout, namely dto timer. Adding this cto
timer seems easily to handle this bug but it's hard to restrict the code
under the rockchip specified context. So after merging this patch, it
sets up the cto timer for all the platforms using dwmmc IP which isn't
ideal but at least we don't advertise new quirk here. Fortunately, no
obvious performance regression was found by test and the pre-existing
similar catch-all timer for sdhci has proved it's an acceptant way to
make the code as robust as possible.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=196321Signed-off-by: NAddy Ke <addy.ke@rock-chips.com>
Signed-off-by: NZiyuan Xu <xzy.xu@rock-chips.com>
[shawn.lin: rewrite the code and the commit msg throughout]
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

This commit modifies dw_mci_probe(), it moves reset assertion before
drv_data->init(host)

Some driver needs to access controller registers in its .init() ops. So,
in order to make such access safe, we should do controller reset before
.init() being called.
Signed-off-by: NWei Li <liwei213@huawei.com>
Signed-off-by: NGuodong Xu <guodong.xu@linaro.org>
Signed-off-by: NChen Jun <chenjun14@huawei.com>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Commit a53e35db ("reset: Ensure drivers are explicit when requesting
reset lines") started to transition the reset control request API calls
to explicitly state whether the driver needs exclusive or shared reset
control behavior. Convert all drivers requesting exclusive resets to the
explicit API call so the temporary transition helpers can be removed.

No functional changes.

Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: linux-mmc@vger.kernel.org
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Change to print the information about when the deprecated "num-slots" DT
binding is being used, as to avoid confusion when browsing the log:

dwmmc_rockchip fe320000.dwmmc: 'num-slots' was deprecated.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Fixes: d30a8f7b ("mmc: dw_mmc: deprecated the "num-slots" property")
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Remove the unnecessary slot variable.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Remove the 'cur_slot'. Instead, just use 'slot'.
There is no multiple slots, so we need to consider only one slot.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Doesn't need to pass the id value for slot functions.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

It doesn't need to use the array of slots anymore.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

dwmmc controller has used the only one slot.
It doesn't need to check the other slots.
Remove the loop about finding slots.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

dwmmc controller is supporting only one slot per a IP.
Even though DWMMC IP is provided the multiple slot, but there is no
usage in real world.
In mmc subsystem, not allow the multiple slot concept.
Then "num-slots" property is deprecated.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.comi>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Using the device_property interfaces allows the dw_mmc driver to work
on platforms which run on either device tree or ACPI.
Signed-off-by: NDavid Woods <dwoods@mellanox.com>
Reviewed-by: NChris Metcalf <cmetcalf@mellanox.com>
Cc: stable@vger.linux.org
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

This reverts commit a6db2c86 ("mmc: dw_mmc: Don't allow Runtime PM for
SDIO cards")'

As dw_mmc now is capable of preventing runtime PM suspend while SDIO IRQs
are enabled, let's drop the less fine-grained method, which is preventing
runtime PM suspend for all SDIO cards - no matter of whether SDIO IRQs are
being enabled or not.

In this way we don't keep the host runtime PM resumed, unless it's really
needed, thus avoiding to waste power.

Especially when SDIO IRQs is supported via a separate out-of-band IRQ line,
which isn't defined by the SDIO standard, typically the SDIO func driver
doesn't enable SDIO IRQs via sdio_claim_irq(). So, for these cases we can
now allow the dwmmc device to be runtime PM suspended in-between requests.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>

To be able to handle SDIO IRQs the dw_mmc device needs to be powered and
providing clock to the SDIO card. Therefore, we must not allow the device
to be runtime PM suspended while SDIO IRQs are enabled.

To fix this, let's increase the runtime PM usage count while the mmc core
enables SDIO IRQs. Later when the mmc core tells dw_mmc to disable SDIO
IRQs, we drop the usage count to again allow runtime PM suspend.

This now becomes the default behaviour for dw_mmc. In cases where SDIO IRQs
can be re-routed as GPIO wake-ups during runtime PM suspend, one could
potentially allow runtime PM suspend. However, that will have to be
addressed as a separate change on top of this one.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>

Convert to use the more lightweight method for processing SDIO IRQs, which
involves the following changes:

- Enable MMC_CAP2_SDIO_IRQ_NOTHREAD when SDIO IRQ is supported and use
  sdio_signal_irq() instead of mmc_signal_sdio_irq().
- Mask the SDIO IRQ before signaling a new one to be processed.
- Implement the ->ack_sdio_irq() callback to unmask the SDIO IRQ.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>

Use new core function mmc_get_dma_dir().
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Too much condition iteration makes the code
less readable. Slightly improve it.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

No functional change intended.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

No need to declar it there, remove it.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

No functional change intended.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

No functional change intended.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

No functional change intended.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>