Since the regulator used for the SDMMC IO voltage is not expected to
draw a lot of current, most systems will probably use an inexpensive
LDO for it. LDO regulators apparently have the feature that they
don't actively drive the voltage down--they wait for other components
in the system to drag the voltage down. Thus they will transition
faster under heavy loads and slower under light loads.
During an SDMMC voltage change from 3.3V to 1.8V, we are almost
certainly under a light load. To be specific:
* The regulator is hooked through pulls to CMD0-3 and DAT. Probably
the CMD pulls are something like 47K and the DAT is something like
10K.
* The card is supposed to be driving DAT0-3 low during voltage change
which will draw _some_ current, but not a lot.
* The regulator is also provided to the SDMMC host controller, but the
SDMMC host controller is in open drain mode during the voltage
change and so shouldn't be drawing much current.
In order to keep the SDMMC host working properly (or for noise
reasons), there might also be a capacitor attached to the SDMMC IO
regulator. This also will have the effect of slowing down transitions
of the regulator, especially under light loads.
From experimental evidence, we've seen the voltage change fail if the
card doesn't detect that the voltage fell to less than about 2.3V when
we turn on the clock. On one device (that admittedly had a 47K CMD
pullup instead of a 10K CMD pullup) we saw that the voltage was just
about 2.3V after 5ms and thus the voltage change would sometimes fail.
Doubling the delay gave margin and made the voltage change work 100%
of the time, despite the slightly weaker CMD pull.
At the moment submitting this as an RFC patch since my problem _could_
be fixed by increasing the pull strength (or using a smaller
capacitor). However being a little bit more lenient to strange
hardware could also be a good thing.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Use the new MMC_CAP2_NO_WRITE_PROTECT to let the core handle the case where
no write protect line is present instead of having custom driver code to
handle it.
dw_mci_of_get_slot_quirks() is slightly refactored to directly modify the
mmc_host capabilities instead of returning a quirk mask.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
card->csd.capacity is defined as "unsigned int", and sector_t is defined as
"u64" or "unsigned long" (depends on CONFIG_LBDAF). Thus, sector_t data
might have strange data (see below). This patch cast it to typeof(sector_t)
Special thanks to coverity <http://www.coverity.com>
ex) if sector_t was u64
unsigned int data;
sector_t sector;
data = 0x800000;
sector = (data << 8); // 0xffffffff80000000
sector = (((typeof(sector_t))data) << 8); // 0x80000000
or
data = 0x80000000;
sector = (data << 8); // 0x0
sector = (((typeof(sector_t))data) << 8); // 0x8000000000
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
card->ext_csd.enhanced_area_offset is defined as "unsigned long long",
and, ext_csd[] is defined as u8.
unsigned long long data might have strange data if first bit of ext_csd[]
was 1. this patch cast it to (unsigned long long)
Special thanks to coverity <http://www.coverity.com>
ex)
u8 data8;
u64 data64;
data8 = 0x80;
data64 = (data8 << 24); // 0xffffffff80000000
data64 = (((unsigned long long)data8) << 24); // 0x80000000;
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Use BUG_ON() instead of an 'if' condition followed by BUG().
The semantic patch that makes this change is available
in scripts/coccinelle/misc/bugon.cocci.
More information about semantic patching is available at
http://coccinelle.lip6.fr/
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Simplify a trivial if-return sequence. Possibly combine with a
preceding function call.
The semantic patch that makes this change is available
in scripts/coccinelle/misc/simple_return.cocci.
More information about semantic patching is available at
http://coccinelle.lip6.fr/
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Simplify a trivial if-return sequence. Possibly combine with a
preceding function call.
The semantic patch that makes this change is available
in scripts/coccinelle/misc/simple_return.cocci.
More information about semantic patching is available at
http://coccinelle.lip6.fr/
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The only user of this driver that has not been converted to fully
device tree is the i.MX35 SoC.
There is a i.MX35-based board (mach-pcm043.c) that uses platform data
to pass wp_gpio and cd_gpio information.
Commit 8d86e4fccc ("mmc: sdhci-esdhc-imx: Call mmc_of_parse()")
broke the platform data case by removing mmc_gpio_request_ro() and
mmc_gpio_request_cd(), so restore the functionality for the non-dt
case.
Also, restore the check for ESDHC_CD_CONTROLLER so that we can still
support the "fsl,cd-controller" property.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
mmc_of_parse() should be placed inside sdhci_esdhc_imx_probe_dt() as it
suits only for the dt case.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Allow to specify in the device-tree that no physical write-protect signal
is connected to a particular instance of a MMC controller. Setting the
property will cause the core will assume that the SD card is always
read-write.
The name for the new property is 'disable-wp' and was chosen based on the
property with the same function from the Synopsys designware mobile storage
host controller DT bindings specification.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
It is not uncommon to see systems where there is no physical write-protect
signal (e.g. when using eMMC or microSD card slots). For some controllers,
which have a dedicated write-protection detection logic (like SDHCI
controllers), the get_ro() callback can return bogus data in such a case.
Instead of handling this on a per controller basis this patch adds a new
capability flag to the MMC core that can be set to specify that the result
of get_ro() is invalid. When the flag is set the core will not call
get_ro() and assume that the card is always read-write.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Check the error code for EOPNOTSUPP and do not print
reset warning in that case.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Retry errored data requests when re-tuning is needed and
add a flag to struct mmc_blk_request so that the retry
is only done once.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
If re-tuning is needed, do it in the recovery path to
give recovery commands a better chance of success.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
CRC errors could possibly be alleviated by
re-tuning so flag re-tuning needed in those cases.
Note this has no effect if re-tuning has not been
enabled.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Make use of mmc core support for re-tuning instead
of doing it all in the sdhci driver.
This patch also changes to flag the need for re-tuning
always after runtime suspend when tuning has been used
at initialization. Previously it was only done if
the re-tuning timer was in use.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
HS400 re-tuning must be done in HS200 mode. Add
the ability to switch from HS400 mode to HS200
mode before re-tuning and switch back to HS400
after re-tuning.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Fabian Frederick
Doug Anderson
Zhangfei Gao
Lars-Peter Clausen
Kuninori Morimoto
Fabio Estevam
Adrian Hunter