Also add TMIO_BBS.
This allows these defines to also be used by zboot.
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
On sh-mobile platforms the SDHI driver was using the tmio_mmc SD/SDIO
MFD cell driver. Now that the tmio_mmc driver has been split into a
core and a separate MFD glue, we can support SDHI natively without the
need to emulate an MFD controller. This also allows to support systems
with an on-SoC SDHI controller and a separate MFD with a TMIO core.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
This is my second attempt to make this enum generally available.
The first attempt added MMCIF_PROGRESS_* to include/linux/mmc/sh_mmcif.h.
However this is not sufficiently generic as the enum will be
used by SDHI boot code.
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch adds support for power regulators.
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This patch is related to re-init processing on suspend/resume.
When card is resuming, some register is reset. If card is removable,
maybe controller should be rescan for card. But if assume card is
non-removable, need to restore the old value at registers.
We store the value of FIFOTH at probe time and then restore it in
dw_mci_resume().
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This patch adds quirks and capabilities to platdata.
Some cards don't use the CDn pin; in that case, we assume the card's
inserted. Some boards need other capabilities. So, we add capabilities
in the board's platdata.
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
When using mmc_try_claim_host the corresponding release
function is mmc_do_release_host, which then also must
be exported.
Reviewed-by: Jonas Aberg <jonas.aberg@stericsson.com>
Reviewed-by: Sebastian Rasmussen <sebastian.rasmussen@stericsson.com>
Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
If we need some quirks, maybe add quirks in future
But now, quirks value set to integer..later we should be confused..
So I think that need bit-shift control.
And If we need not any quirks, we didn't set anything..
(Need not DW_MCI_QUIRK_NONE)
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some sdio card are not following sdio standard, and do not work
when the sdio bus's clock is gated.
To keep functionnality for all legacy driver, we turn this quirk on
for every sdio card.
Drivers needs to disable the quirk manually when someone verifies that
their supported card works with clock gating.
Signed-off-by: Pierre Tardy <tardyp@gmail.com>
Acked-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some cards have quirks valid for every platforms using current
platform quirk hooks leads to a lot of code and debug duplication.
So we inspire a bit from what exists in PCI subsystem and do our own
per vendorid/deviceid quirk. We still drop the complexity of the pci
quirk system (with special section tables, and so on).
That can be added later if needed.
Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Enhanced area feature is a new feature defined in eMMC4.4 standard. This
user data area provides higher performance/reliability, at the expense
of using twice the effective media space due to the area using SLC.
The MMC driver now reads out the enhanced area offset and size and adds
them to the device attributes in sysfs. Enabling the enhanced area can
only be done once, and should be done in manufacturing. To use this
feature, bit ERASE_GRP_DEF should also be set.
Documentation/ABI/testing/sysfs-devices-mmc describes the two new
attributes.
Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
When using the I/O accessors in raw mode from the boot stubs we don't
want to bother with any of the complexity associated with readl/writel
and friends. Furthermore, utilization within the context of the host
driver itself is all performed on an ioremapped window, so using the
__raw variants there doesn't pose any problem either.
If and when barriers need to be added in the future, these will need to
be explicitly written out, but this is so far not a concern for any of
the affected CPUs in question.
This fixes up the link error introduced by the ARM tree via its barrier
refactoring:
arch/arm/boot/compressed/mmcif-sh7372.o: In function `mmcif_loader':
mmcif-sh7372.c:(.text+0x9e8): undefined reference to `outer_cache
Following the change in:
http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=6275/1
Reported-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This adds the mmc host driver for the Synopsys DesignWare mmc
host controller, found in a number of embedded SoC designs.
Signed-off-by: Will Newton <will.newton@imgtec.com>
Reviewed-by: Matt Fleming <matt@console-pimps.org>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some controllers misparse segment length 0 as being 0, not 65536. Add
a quirk to deal with it.
Signed-off-by: Olof Johansson <olof@lixom.net>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some old MMC devices fail with the 4/8 bits the driver tries to use
exclusively. This patch adds a test for the given bus setup and falls
back to the lower bit mode (until 1-bit mode) when the test fails.
[Major rework and refactoring by tiwai]
[Quirk addition and many fixes by prakity]
Signed-off-by: Aries Lee <arieslee@jmicron.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Philip Rakity <prakity@marvell.com>
Tested-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Upon system resume, SDIO core must reinitialize cards that were
powered off during suspend.
If the card had its power kept during suspend (and thus it is
'powered-resumed'), SDIO core performs only a limited reinitializing,
mainly needed to make sure that the card wasn't removed/replaced.
If a __nonremovable__ card is powered-resumed, we can safely skip the
reinitializing phase.
Note: 9b966aa (mmc: sdio: fully reconfigure oldcard on resume) removed
the bus width reconfiguration since mmc_sdio_init_card already does it.
It is brought back now in case mmc_sdio_init_card is skipped.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
JMicron 388 SD/MMC combo controller supports the 1.8V low-voltage for
SD, but MMC doesn't work with the low-voltage, resulting in an error
at probing.
This patch adds the support for multiple voltage mask per device type,
so that SD works with 1.8V while MMC forces 3.3V. Here new ocr_avail_*
fields for each device are introduced, so that the actual OCR mask is
switched dynamically.
Also, the restriction of low-voltage in core/sd.c is removed when the
bit is allowed explicitly via ocr_avail_sd mask.
This patch was rewritten from scratch based on Aries' original code.
Signed-off-by: Aries Lee <arieslee@jmicron.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
This patch modifies the MMC core code to optionally call the set_ios()
operation on the driver with the clock frequency set to 0 (gate) after
a grace period of at least 8 MCLK cycles, then restore it (ungate)
before any new request. This gives the driver the option to shut down
the MCI clock to the MMC/SD card when the clock frequency is 0, i.e.
the core has stated that the MCI clock does not need to be generated.
It is inspired by existing clock gating code found in the OMAP and
Atmel drivers and brings this up to the host abstraction. Gating is
performed before and after any MMC request.
This patchset implements this for the MMCI/PL180 MMC/SD host controller,
but it should be simple to switch OMAP/Atmel over to using this instead.
mmc_set_{gated,ungated}() add variable protection to the state holders
for the clock gating code. This is particularly important when ordinary
.set_ios() calls would race with the .set_ios() call resulting from a
delayed gate operation.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Reviewed-by: Chris Ball <cjb@laptop.org>
Tested-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
As the only caller of sh_mmcif_boot_do_read() is
sh_mmcif_boot_slurp() the configuration portion of
sh_mmcif_boot_slurp() can be merged into sh_mmcif_boot_do_read().
Once this is done sh_mmcif_boot_slurp() is only a call
to sh_mmcif_boot_do_read() with platform specific information -
the offset that images are stored on MMC. So make the
sh_mmcif_boot_do_read() call directly from platform code
and remove sh_mmcif_boot_slurp() altogether.
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Allow MMCIF_PROGRESS_* to be shared.
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The 16-19th bits of CE_CLK_CTRL set the
MMC clock frequency.
Cc: Yusuke Goda <yusuke.goda.sx@renesas.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This resolves a regression that I introduced in
"mmc, sh: Move constants to sh_mmcif.h". Having
examined the manual and tested the code on an AP4EVB board
it seems that the correct sequence is.
1) Write 1 to bit 31 and zeros to all other bits
2) Write zero to all bits
Cc: Yusuke Goda <yusuke.goda.sx@renesas.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The MMCIF controller on sh-mobile platforms can use the DMA controller for data
transfers. Interface to the SH dmaengine driver to enable DMA. We also have to
lower the maximum number of segments to match with the number od DMA
descriptors on SuperH, this doesn't significantly affect driver's PIO
performance.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Some board/card/host configurations are not capable of powering off the
card after boot.
To support such configurations, and to allow smoother transition to
runtime PM behavior, MMC_CAP_POWER_OFF_CARD is added, so hosts need to
explicitly indicate whether it's OK to power off their cards after boot.
SDIO core will enable runtime PM for a card only if that cap is set.
As a result, the card will be powered down after boot, and will only
be powered up again when a driver is loaded (and then it's up to the
driver to decide whether power will be kept or not).
This will prevent sdio_bus_probe() failures with setups that do not
support powering off the card.
Reported-and-tested-by: Daniel Drake <dsd@laptop.org>
Reported-and-tested-by: Arnd Hannemann <arnd@arndnet.de>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This moves some constants from sh_mmcif.c to sh_mmcif.h
so that they can be used in sh_mmcif_boot_init().
It also alters the definition of SOFT_RST_OFF from (0 << 31) to
~SOFT_RST_ON (= ~(1 << 31)). The former seems bogus. The latter is
consistent with the code in sh_mmcif_boot_init().
Cc: Yusuke Goda <yusuke.goda.sx@renesas.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Presently the extern inline case results in a compiler warning on ARM due
to the memory barrier definition used in the I/O routines. These
ultimately all want to be static inline anyways, so just convert them all
in place.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
In some platforms (e.g. AP4EVB) the card detect pin of a slot is not
directly connected to the sh_mmcif controller, so that polling needs
to be used. To overcome the overhead induced by querying the controller
on each poll cycle, card detection can be handled in the platform code
more efficiently.
This patch exposes a get_cd hook for that purpose.
Signed-off-by: Arnd Hannemann <arnd@arndnet.de>
Tested-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc: (66 commits)
mmc: add new sdhci-pxa driver for Marvell SoCs
mmc: make number of mmcblk minors configurable
mmc_spi: Recover from CRC errors for r/w operation over SPI.
mmc: sdhci-pltfm: add -pltfm driver for imx35/51
mmc: sdhci-of-esdhc: factor out common stuff
mmc: sdhci_pltfm: pass more data on custom init call
mmc: sdhci: introduce get_ro private write-protect hook
mmc: sdhci-pltfm: move .h file into appropriate subdir
mmc: sdhci-pltfm: Add structure for host-specific data
mmc: fix cb710 kconfig dependency warning
mmc: cb710: remove debugging printk (info duplicated from mmc-core)
mmc: cb710: clear irq handler on init() error path
mmc: cb710: remove unnecessary msleep()
mmc: cb710: implement get_cd() callback
mmc: cb710: partially demystify clock selection
mmc: add a file to debugfs for changing host clock at runtime
mmc: sdhci: allow for eMMC 74 clock generation by controller
mmc: sdhci: highspeed: check for mmc as well as sd cards
mmc: sdhci: Add Moorestown device support
mmc: sdhci: Intel Medfield support
...
The custom init call may need more data to perform its job, so we pass
it a pointer to pdata, too. Also, always use the platform_id specific
data even if platform_data is present. Doing that, platform_data can
additionally be parsed by init() for board-specific information (via
sdhci->mmc->parent).
(Note: the old behaviour was that you could override the platform_id
specific data with your own. However, one can still do this by using the
"sdhci" id instead of "sdhci-<something>".)
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Tested-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Make use of the include/linux/mmc directory.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Tested-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Allow power save/restore and their relevant mmc_bus_ops handlers
exit with a return value.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some platforms based on sdhci-pltfm need to set their own quirks.
Previously to this patch, the quirks were in drivers/mmc/host/sdhci.h.
This patch splits drivers/mmc/host/sdhci.h into two parts:
* drivers/mmc/host/sdhci.h includes the HC registers and I/O accessors.
* include/linux/mmc/sdhci.h includes the sdhci structure and quirks.
Instead of including drivers/mmc/host/sdhci.h, -pltfm drivers should
now include include/linux/mmc/sdhci.h and include/linux/sdhci-pltfm.h.
This patch avoids adding/changing the calls/flags in the
sdhci_pltfm_data structure. It has been tested on STM platforms
(e.g. STx7106, STx7108, STx5206) where the driver is configured
and used as shown in the example below:
[snip]
static int mmc_pad_resources(struct sdhci_host *sdhci)
{
if (!devm_stm_pad_claim(sdhci->mmc->parent,
&stx7108_mmc_pad_config,
dev_name(sdhci->mmc->parent)))
return -ENODEV;
return 0;
}
static struct sdhci_pltfm_data stx7108_mmc_platform_data = {
.init = mmc_pad_resources,
.quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
};
static struct platform_device stx7108_mmc_device = {
.name = "sdhci",
[snip]
Note: drivers/mmc/host/sdhci.h now also includes linux/mmc/sdhci.h,
and no modifications should be needed on other sdhci-<XXX> drivers.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
One flaw with DDR support is that MMC core does not inform the driver
which DDR mode it has selected. This patch expands the ios->ddr flag
to do that.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
The DDR support patch needs the following fixes:
- The block driver does not need to know about DDR, any more
than it needs to know about bus width.
- Not only the card must be switched to DDR mode. The host
controller must also be configured, which is done through
the 'set_ios()' function.
- Do not set the DDR mode state until after the switch command
is successful.
- Setting block length is not supported in DDR mode. Make that
a core function and change the other place it is used (mmc_test)
also.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Add support for Dual Data Rate MMC cards as defined in the 4.4
specification.
Signed-off-by: Hanumath Prasad <hanumath.prasad@stericsson.com>
Cc: linux-mmc@vger.kernel.org
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Tested-by Zhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
After discovering a problem in regulator reference counting I took Mark
Brown's advice to move the reference count into the MMC core by making the
regulator status a member of struct mmc_host.
I took this opportunity to also implement NULL versions of
the regulator functions so as to rid the driver code from
some ugly #ifdef CONFIG_REGULATOR clauses.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Sundar Iyer <sundar.iyer@stericsson.com>
Cc: Daniel Mack <daniel@caiaq.de>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Matt Fleming <matt@console-pimps.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Cliff Brake <cbrake@bec-systems.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
In the latest releases of the mmc driver, the freq during initialization
is set to a fixed 400 Khz. This was reportedly too fast for several
users. As there doesn't seem to be an ideal frequency
which-works-for-all, Pierre suggested to let the driver try several
frequencies.
This patch implements that idea. It will try mmc-initialization using
several frequencies from an array 400, 300, 200 and 100.
In case SDIO is broken, it'll still try to detect SDMEM, also at different
freqs.
Signed-off-by: Hein Tibosch <hein_tibosch@yahoo.es>
Cc: Pierre Ossman <pierre@ossman.eu>
Reviewed-by: Chris Ball <cjb@laptop.org>
Tested-by: Chris Ball <cjb@laptop.org>
Cc: Ben Nizette <bn@niasdigital.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: Matt Fleming <matt@console-pimps.org>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
There are two checks that need to be made when determining whether a
card is removable. A host controller may set MMC_CAP_NONREMOVABLE if the
controller does not support removing cards (e.g. eMMC), in which case
the card is physically non-removable. Also the 'mmc_assume_removable'
module parameter can be configured at module load time, in which case
the card may be logically non-removable.
A helper function keeps the logic in one place so that code always
checks both conditions.
Because this new function is likely to be called from modules we now
need to export the mmc_assume_removable symbol.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
Global symbols should use their subsystem name in a prefixed fashion.
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Conversion from struct device to struct mmc_card is used more than in one
place. Due to this it's better to have public macro for such thing.
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
We have deprecated the distinction between hardware and physical
segments in the block layer. Consolidate the two limits into one in
drivers/mmc/.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
The introduction of support for SD combo cards breaks the initialization
of all CSR SDIO chips. The GO_IDLE (CMD0) in mmc_sd_get_cid() causes CSR
chips to be reset (this is non-standard behavior).
When initializing an SDIO card check for a combo card by using the memory
present bit in the R4 response to IO_SEND_OP_COND (CMD5). This avoids the
call to mmc_sd_get_cid() on an SDIO-only card.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Acked-by: Michal Mirolaw <mirq-linux@rere.qmqm.pl>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SD/MMC cards tend to support an erase operation. In addition, eMMC v4.4
cards can support secure erase, trim and secure trim operations that are
all variants of the basic erase command.
SD/MMC device attributes "erase_size" and "preferred_erase_size" have been
added.
"erase_size" is the minimum size, in bytes, of an erase operation. For
MMC, "erase_size" is the erase group size reported by the card. Note that
"erase_size" does not apply to trim or secure trim operations where the
minimum size is always one 512 byte sector. For SD, "erase_size" is 512
if the card is block-addressed, 0 otherwise.
SD/MMC cards can erase an arbitrarily large area up to and
including the whole card. When erasing a large area it may
be desirable to do it in smaller chunks for three reasons:
1. A single erase command will make all other I/O on the card
wait. This is not a problem if the whole card is being erased, but
erasing one partition will make I/O for another partition on the
same card wait for the duration of the erase - which could be a
several minutes.
2. To be able to inform the user of erase progress.
3. The erase timeout becomes too large to be very useful.
Because the erase timeout contains a margin which is multiplied by
the size of the erase area, the value can end up being several
minutes for large areas.
"erase_size" is not the most efficient unit to erase (especially for SD
where it is just one sector), hence "preferred_erase_size" provides a good
chunk size for erasing large areas.
For MMC, "preferred_erase_size" is the high-capacity erase size if a card
specifies one, otherwise it is based on the capacity of the card.
For SD, "preferred_erase_size" is the allocation unit size specified by
the card.
"preferred_erase_size" is in bytes.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ben Gardiner <bengardiner@nanometrics.ca>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
