MFC: r340495

- Restore setting the clock for devices which support the default/legacy
transfer mode only (lost with r321385). [1]
- Similarly, don't try to set the power class on MMC devices that comply
to version 4.0 of the system specification but are operated in default/
legacy transfer or 1-bit bus mode as no power class is specified for
these cases. Trying to set a power class nevertheless resulted in an -
albeit harmless - error message.

PR: 231713 [1]

MFC: r333647, r338275, r338280, r338513

- If present, take advantage of the R/W cache of eMMC revision 1.5 and
later devices. These caches work akin to the ones found in HDDs/SSDs
that ada(4)/da(4) also enable if existent, but likewise increase the
likelihood of data loss in case of a sudden power outage etc. On the
other hand, write performance is up to twice as high for e. g. 1 GiB
files depending on the actual chip and transfer mode employed.
For maximum data integrity, the usage of eMMC caches can be disabled
via the hw.mmcsd.cache tunable.
- Get rid of the NOP mmcsd_open().
- Obtain the bus mode (MMC or SD) from the directly superordinated
bus rather than reaching up to the bridge and use the cached mode
in mmcsd_delete(), too.
- Use le32dec(9) for decoding EXT_CSD values where it makes sense. [1]
- Locally cache some instance variable values in mmc_discover_cards()
in order to improve the code readability a bit.

Obtained from: NetBSD [1]

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

MFC: r327929

Use the correct revision specifier (EXT_CSD revision rather than
system specification version) for deciding whether the EXT_CSD
register includes the EXT_CSD_GEN_CMD6_TIME field.

Submitted by: Masanobu SAITOH

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

MFC: r322209

- If available, use TRIM instead of ERASE for implementing BIO_DELETE.
This also involves adding a quirk table as TRIM is broken for some
Kingston eMMC devices, though. Compared to ERASE (declared "legacy"
in the eMMC specification v5.1), TRIM has the advantage of operating
on write sectors rather than on erase sectors, which typically are
of a much larger size. Thus, employing TRIM, we don't need to fiddle
with coalescing BIO_DELETE requests that are also of (write) sector
units into erase sectors, which might not even add up in all cases.
- For some SanDisk iNAND devices, the CMD38 argument, e. g. ERASE,
TRIM etc., has to be specified via EXT_CSD[113], which now is also
handled via a quirk.
- My initial understanding was that for eMMC partitions, the granularity
should be used as erase sector size, e. g. 128 KB for boot partitions.
However, rereading the relevant parts of the eMMC specification v5.1,
this isn't actually correct. So drop the code which used partition
granularities for delmaxsize and stripesize. For the most part, this
change is a NOP, though, because a) for ERASE, mmcsd_delete() used
the erase sector size unconditionally for all partitions anyway and
b) g_disk_limit() doesn't actually take the stripesize into account.
- Take some more advantage of mmcsd_errmsg() in mmcsd(4) for making
error codes human readable.

MFC: r319350, r321385, r321490, r321588, r321948

o Use SDHCI_CAN_DRIVE_TYPE_{A,C,D} to check for driver type support in
SDHCI_CAPABILITIES2 instead of SDHCI_CTRL2_DRIVER_TYPE_{A,C,D} which
are meant for setting the driver type in SDHCI_HOST_CONTROL2.

o Add support for eMMC HS200 and HS400 bus speed modes at 200 MHz to
sdhci(4), mmc(4) and mmcsd(4).

On the system where the addition of DDR52 support increased the read
throughput to ~80 MB/s (from ~45 MB/s at high speed), HS200 yields
~154 MB/s and HS400 ~187 MB/s, i. e. performance now has more than
quadrupled compared to pre-r315598 (pre-r318494 in stable/11).

However, in fact this isn't a feature-only change; there are boards
based on Intel Bay Trail where DDR52 is problematic and the suggested
workaround is to use HS200 mode instead. So far exact details are
unknown, however, i. e. whether that's due to a defect in these SoCs
or on the boards.

Moreover, due to the above changes requiring to be aware of possible
MMC siblings in the fast path of mmc(4), corresponding information
now is cached in mmc_softc. As a side-effect, mmc_calculate_clock(),
now longer will trigger a panic in low memory situations and all of
mmc(4) operate on the same set of child devices.

o Fix a bug in the failure reporting of mmcsd_delete() that could lead
to a panic.

o Fix 2 bugs on resume, one in mmcsd(4) that could lead to a panic and
another one in mmc(4) that could lead to devices no longer working.

o Fix a memory leak in mmcsd_ioctl() in case copyin(9) fails. [1]

o Fix missing variable initialization in mmc_switch_status(). [2]

o Fix R1_SWITCH_ERROR detection in mmc_switch_status(). [3]

o Handle the case of device_add_child(9) failing, for example due to
a memory shortage, gracefully in mmc(4) and sdhci(4), including not
leaking memory for the instance variables in case of mmc(4), also
fixing [4].

o Correctly use the size of a pointer rather than that of a pointer to
a pointer (this bug was present in head r321385 only, i. e. not in a
stable branch). [5]

o Handle the case of an unknown SD CSD version in mmc_decode_csd_sd()
gracefully instead of calling panic(9).

o Again, check and handle the return values of some additional function
calls in mmc(4) instead of assuming that everything went right or mark
non-fatal errors by casting the return value to void.

o Correct a typo in the Linux IOCTL compatibility; it should have been
MMC_IOC_MULTI_CMD rather than MMC_IOC_CMD_MULTI.

o Now that we are reaching ever faster speeds (more improvement in this
regard is to be expected when adding ADMA support to sdhci(4)), apply
a few micro-optimizations to mmc(4), mmcsd(4) and sdhci(4).

o Correct confusing and error prone mix-ups between "br" or "bridge" in
mmc(4) and mmcsd(4) where - according to the terminology outlined in
comments of bridge.h and mmcbr_if.m around since their addition in
r163516 - the bus is meant and used instead.

o Remove comment lines from bridge.h incorrectly suggesting that there
would be a MMC bridge base class driver.

o Update comments in bridge.h regarding the star topology of SD and SDIO;
since version 3.00 of the SDHCI specification, for eSD and eSDIO bus
topologies are actually possible in form of so called "shared buses"
(in some subcontext later on renamed to "embedded" buses).

Reported by: Coverity
CID: 1372612 [1], 1372624 [2], 1372594 [3], 1007069 [4],
1378432 [5]

MFC: r315598

o Add support for eMMC DDR bus speed mode up to 52 MHz to sdhci(4)
and mmc(4). Given that support for DDR52 is not denoted by SDHCI
capability registers, availability of that timing is indicated by
a new quirk SDHCI_QUIRK_MMC_DDR52 and only enabled for Intel SDHCI
controllers so far.

Compared to 50 MHz at SDR high speed typically yielding ~45 MB/s
read throughput with the eMMC chips tested, read performance goes
up to ~80 MB/s at DDR52.

As a side-effect, this change also fixes communication with some
eMMC devices at SDR high speed mode due to the signaling voltage
and UHS bits in the SDHCI controller no longer being left in an
inappropriate state.

o In sdhci(4), add two tunables hw.sdhci.quirk_clear as well as
hw.sdhci.quirk_set, which (when hooked up in the front-end)
allow to set/clear sdhci(4) quirks for debugging and testing
purposes. However, especially for SDHCI controllers on the
PCI bus which have no specific support code so far and, thus,
are picked up as generic SDHCI controllers, hw.sdhci.quirk_set
allows for setting the necessary quirks (if required).

o In mmc(4), check and handle the return values of some more
function calls instead of assuming that everything went right.
In case failures actually are not problematic, indicate that
by casting the return value to void.

MFC: r312939, r313250, r314811 (partial), r314887 (partial), r315760,
r315845, 315430, r317981, r315466

o Fix some overly long lines, whitespace and other bugs according to
style(9) as well as spelling etc. in mmc(4), mmcsd(4) and sdhci(4).

o In the mmc(4) bridges and sdhci(4) (bus) front-ends:
- Remove redundant assignments of the default bus_generic_print_child
device method,
- use DEVMETHOD_END,
- use NULL instead of 0 for pointers.

o Trim/adjust includes.

o Add and use a MMC_DECLARE_BRIDGE macro for declaring mmc(4) bridges
as kernel drivers and their dependency onto mmc(4).

o Add support for eMMC "partitions". Besides the user data area, i. e.
the default partition, eMMC v4.41 and later devices can additionally
provide up to:
1 enhanced user data area partition
2 boot partitions
1 RPMB (Replay Protected Memory Block) partition
4 general purpose partitions (optionally with a enhanced or extended
attribute)

Besides simply subdividing eMMC devices, some Intel NUCs having UEFI
code in the boot partitions etc., another use case for the partition
support is the activation of pseudo-SLC mode, which manufacturers of
eMMC chips typically associate with the enhanced user data area and/
or the enhanced attribute of general purpose partitions.

CAVEAT EMPTOR: Partitioning eMMC devices is a one-time operation.

o Now that properly issuing CMD6 is crucial (so data isn't written to
the wrong partition for example), make a step into the direction of
correctly handling the timeout for these commands in the MMC layer.
Also, do a SEND_STATUS when CMD6 is invoked with an R1B response as
recommended by relevant specifications.

o Add an IOCTL interface to mmcsd(4); this is sufficiently compatible
with Linux so that the GNU mmc-utils can be ported to and used with
FreeBSD (note that due to the remaining deficiencies outlined above
SANITIZE operations issued by/with `mmc` currently most likely will
fail). These latter have been added to ports as sysutils/mmc-utils.
Among others, the `mmc` tool of mmc-utils allows for partitioning
eMMC devices (tested working).

o For devices following the eMMC specification v4.41 or later, year 0
is 2013 rather than 1997; so correct this for assembling the device
ID string properly.

o Let mmcsd.ko depend on mmc.ko. Additionally, bump MMC_VERSION as at
least for some of the above a matching pair is required.

o In the ACPI front-end of sdhci(4) describe the Intel eMMC and SDXC
controllers as such in order to match the PCI one.
Additionally, in the entry for the 80860F14 SDXC controller remove
the eMMC-only SDHCI_QUIRK_INTEL_POWER_UP_RESET.

MFC: r310309, r310340-310341, r311664, r311793-r311794

o sdhci/mmc: Minor whitespace cleanups

o Add Braswell PCI IDs for Intel Cherryview

o mmc: Accept even lower voltage for Cherryview

And HP x2 210, per DragonFlyBSD 240bd9cd58f8259c12c14a8006837e698.

o In mmcsd_task(), bio_resid was not being set to 0 on a successful read
or write, resulting in random short-read and short-write returns for
requests. Fixing this fixes nominal block I/O via mmcsd(4).

Obtained from: DragonFlyBSD (fd4b97583be1a1e57234713c25f6e81bc0411cb0)

o Add support for Intel Apollo Lake and Bay Trail eMMC PCI controllers.

o Flesh out the support for Intel Braswell eMMC controllers further.

o In sdhci_init_slot(), use the right capability field for determining
the announced bus width based on MMC_CAP_*_BIT_DATA.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix fallout from r292180 (Dec 2015)... ensure that every driver which has
a DRIVER_MODULE() referencing mmc_driver has a MODULE_DEPEND() on mmc. This
is because the kernel linker only searches for symbols in dependent modules,
so loading sdhci_pci (and other bus-flavors of sdhci) would fail when mmc
was not compiled into the kernel (even if you hand-loaded mmc first).

(Thanks to jilles@ for providing the vital clue about the kernel linker.)

Flag sysctl hw.mmc.debug as a tunable, since often you want to debug the
bus probing during system startup.

Move the DRIVER_MODULE() statements that declare mmc(4) to be a child of
the various bridge drivers out of dev/mmc.c and into the bridge drivers.

Requested by: jhb (almost two years ago; better late than never)

Fix freescale sdhc driver, and add it to the files list.

Also, add it to the mmc DRIVER_MODULE attachment list.

Deselect the sd card before re-selecting it when working around a problem
with some cards that causes them to become deselected after probing for
switch capabilities. The old workaround fixes the behavior with some cards,
but causes problems with the cards the behave correctly and don't become
deselected. Forcing a deselect then reselect appears to work correctly
with all cards in initial testing.

Add the MMC/SD driver for Allwinner SoCs.

This is based on the patch sent by Alexander Fedorov with the following
fixes/improvements:

- Better error handling;
- Clock is derived from PLL6 (obtained from netbsd);
- No more unnecessary busy loops on interrupt handler;
- style(9) fixes and code cleanup.

I also want to thanks Martin Galvan who has sent an alternative
implementation with some interesting fixes.

Tested on CubieBoard2, Banana-Pi (thanks to netgate!) and Cubieboard1
(Pratik Singhal).

This is intended to pave the way for the upcoming GSoC work (and make
easier the build of images for the supported boards).

PR: 196081
Submitted by: Alexander Fedorov <alexander.fedorov@rtlservice.com>

Re-select the SD card before getting the SD status. On a couple Atmel
boards, this prevents some error messages during enumeration and also
gives us the correct erase block size. They appear to be harmless
elsewhere.

# Note: we treat too many commands as 'can't fail' if they don't work
# after a couple of retries. We need to fix that, but not today...

Add necessary changes to support various Amlogic SoC devices
specially aml8726-m6 and aml8726-m8b SoC based devices.
aml8726-m6 SoC exist in devices such as Visson ATV-102.
Hardkernel ODROID-C1 board has aml8726-m8b SoC.

The following support is included:
Basic machdep code
SMP
Interrupt controller
Clock control driver (aka gate)
Pinctrl
Timer
Real time clock
UART
GPIO
I2C
SD controller
SDXC controller
USB
Watchdog
Random number generator
PLL / Clock frequency measurement
Frame buffer

Submitted by: John Wehle
Approved by: stas (mentor)

MMC: Signal HC capability to (e)MMC.

Summary:
For new eMMC chips, we must signal controller HC capability in OP_COND command.

Reviewers: imp, ian

Reviewed By: ian

Differential Revision: https://reviews.freebsd.org/D1920

Always select the card before we do the 4.x specific stuff and
deselect it after setting the block size. This is a similar bug that
was fixed elsewhere, but not here. This makes sure that we leave the
card deselected at the end of the loop, and we don't send any commands
to the card without it selected.

Reviewed by: ian@

Log mmc and sd command failures. Reporting of routine expected errors,
such as timeouts while probing a bus or testing for a feature, is
squelched. Also, error reporting is limited to 5 events per second,
because when an sdcard goes bad on a low-end embedded board, flooding
the console at high speed isn't helpful.

Original logging code contributed by Michal Meloun, but then I fancied
it up with squelching and ppsratecheck.

Don't deselect the card too soon. To set the block size or switch the
function parameters, the card has to be in transfer state. If it is in
the idle state, the commands are ignored. This caused us not to set
the proper parameters that we later assume to be present, leading to
downstream failures of the card / interface as our state machine
mismatches the card's.

Submitted by: Svatopluk Kraus <onwahe at gmail.com>, Michal Meloun
<meloun at miracle.cz>

Add driver for Synopsys DesignWare Mobile Storage Host Controller.

Sponsored by: DARPA, AFRL

Export an mmc or sd card's serial number from the mmc layer as an ivar.
In the mmcsd layer use this value to populate disk->d_ident. Also set
disk->d_descr to the full set of card identification info (includes vendor,
model, manufacturing date, etc).

If no compatible cards were found after probing the bus, say so.

Sort the list.

Add the imx sdhci controller.

Don't give up so easily on failure of CMD55 to put the card into app-cmd
mode. We don't know why it failed, so we can't know that a retry will
also fail (the low-level driver might have reset the controller state
machine or something similar that would allow a retry to work).

Make the standard sdhci(4) driver work for the TI OMAP family SoCs.
The MMCHS hardware is pretty much a standard SDHCI v2.0 controller with a
couple quirks, which are now supported by sdhci(4) as of r254507.

This should work for all TI SoCs that use the MMCHS hardware, but it has
only been tested on AM335x right now, so this enables it on those platforms
but leaves the existing ti_mmchs driver in place for other OMAP variants
until they can be tested.

This initial incarnation lacks DMA support (coming soon). Even without it
this improves performance pretty noticibly over the ti_mmchs driver,
primarily because it now does multiblock IO.

Consistently init all mmc request, command, and data structures to zero
before using them.

Handle command retries for commands originating at the mmc layer, and
ensure that all such commands have a non-zero retry count except for those
that are expected to fail (for example, because they are used to probe for
feature support).

While it is possible to pass a retry count down to the hardware driver in
the command request structure, no hardware driver currently implements any
retry logic. The hardware doesn't know much about the context of a single
request, so it makes more sense to handle retries at a layer that does.

This adds retry loops to the mmc_wait_for_cmd() and mmc_wait_for_app_cmd()
functions. These functions are the gateway from other code within mmc.c
to the hardware. App commands are a sequence of two commands and a retry
has to rerun both of them in order, so it needs its own retry loop.

Retry looping is specifically NOT implemented in mmc_wait_for_request()
because it is the gateway for children on the bus, and they have to
implement their own retry logic depending on what makes sense for them.

During card identification, run the bus at 400KHz, not the minimum
speed the bus claims to be capable of. The 400KHz speed is dictated
by the SD and MMC standards.

Print the card relative address in hex, because that's what all the
other debugging output does (when it appears in command arguments,
for example).

Add Xilinx Zynq ARM/FPGA SoC support to FreeBSD/arm port.

Submitted by: Thomas Skibo <ThomasSkibo (at) sbcglobal.net>
Tested by: wkoszek (ZedBoard)
Reviewed by: wkoszek, freebsd-arm@ (no objections raised)

Set the backlink in mmc commands to the mmc request that contains them.

Fix highest voltage detection

Submitted by: Daisuke Aoyama <aoyama at peach.ne.jp>
Approved by: imp@

Use %u for unsigned serial number

Add BCM2835 SDHCI driver and enable it in Raspberry Pi config

Split sdhci driver in two parts: sdhci and sdhci_pci.
sdchi encapsulates a generic SD Host Controller logic that relies on
actual hardware driver for register access.

sdhci_pci implements driver for PCI SDHC controllers using new SDHCI
interface

No kernel config modifications are required, but if you load sdhc
as a module you must switch to sdhci_pci instead.

Remove an unneeded NULL check after M_WAITOK.

Merging of projects/armv6, part 10

- Support for Texas Instruments SoCs:
- AM335x
- OMAP4

- Kernel configs, DTS for Beaglebone and Pandaboard

Submitted by: Ben Gray, Damjan Marion

Add missing prototypes. While at it, sort them alphabetically.

MFC after: 3 days

- Fix some typos in mmc_acquire_bus() and mmc_send_csd().
- Fix some math errors in mmc_decode_csd_sd().
- Fix incorrect arguments to mmc_send_app_op_cond() in mmc_go_discovery().
- Add reporting of CSD for debug purposes.
- Add detection (and skipping) of password-locked cards.
- Add setting of block length on card if necessary.

Submitted by: Patrick Kelsey
MFC after: 3 days

o Fixes:
- When switching to 4-bit operation, send a SET_CLR_CARD_DETECT command
to disconnect the card-detect pull-up resistor from the DAT3 line before
sending the SET_BUS_WIDTH command.
- Add the missing "reserved" zero entry to the mantissa table used to
decode various CSD fields. This was causing SD cards to report that they
could run at 30 MHz instead of the maximum 25 MHz mandated in the spec.
o Enhancements:
- At the MMC layer, format various info from the CID into a string that
uniquely identifies the card instance (manufacturer number, serial
number, product name and revision, etc). Export it as an instance
variable.
- At the MMCSD layer, display the formatted card ID string, and also
report the clock speed of the hardware (not the card's max speed), and
the number of bits and number of blocks per transfer. It comes out like
this now:
mmcsd0: 968MB <SD SD01G 8.0 SN 276886905 MFG 08/2008 by 3 SD> at mmc0
22.5MHz/4bit/128-block
o Use DEVMETHOD_END.
o Use NULL instead of 0 for pointers.

PR: 156496
Submitted by: Ian Lepore
MFC after: 1 week

Mark all SYSCTL_NODEs static that have no corresponding SYSCTL_DECLs.

The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.

Fix read_ivar implementation for MMC and SD.

1. Both mmc_read_ivar() and sdhci_read_ivar() use the expression
'*(int *)result = val' to assign to result which is uintptr_t *.
This does not work on big-endian 64 bit systems.

2. The media_size ivar is declared as 'off_t' which does not fit
into uintptr_t in 32bit systems, change this to long.

Submitted by: kanthms at netlogicmicro com (initial version)

Fix 32bit bit fields handling. This fixes card serial number fetching.
It was just a cosmetic issue, because that number is only reported in logs.

Reported by: Michael Butler on current@

Wait for commands to complete 10 times longer. This makes my A-DATA 32GB SDHC
card being detected.

Reviewed by: imp
MFC after: 2 weeks

Report relative card address to NewBus as location string.

Temporarily revert the new-bus locking for 8.0 release. It will be
reintroduced after HEAD is reopened for commits by re@.

Approved by: re (kib), attilio

Make the newbus subsystem Giant free by adding the new newbus sxlock.
The newbus lock is responsible for protecting newbus internIal structures,
device states and devclass flags. It is necessary to hold it when all
such datas are accessed. For the other operations, softc locking should
ensure enough protection to avoid races.

Newbus lock is automatically held when virtual operations on the device
and bus are invoked when loading the driver or when the suspend/resume
take place. For other 'spourious' operations trying to access/modify
the newbus topology, newbus lock needs to be automatically acquired and
dropped.

For the moment Giant is also acquired in some key point (modules subsystem)
in order to avoid problems before the 8.0 release as module handlers could
make assumptions about it. This Giant locking should go just after
the release happens.

Please keep in mind that the public interface can be expanded in order
to provide more support, if there are really necessities at some point
and also some bugs could arise as long as the patch needs a bit of
further testing.

Bump __FreeBSD_version in order to reflect the newbus lock introduction.

Reviewed by: ed, hps, jhb, imp, mav, scottl
No answer by: ariff, thompsa, yongari
Tested by: pho,
G. Trematerra <giovanni dot trematerra at gmail dot com>,
Brandon Gooch <jamesbrandongooch at gmail dot com>
Sponsored by: Yahoo! Incorporated
Approved by: re (ksmith)

read_ivar takes a uintptr_t * not a u_char *.

o Define some symbols for a few items that are bare constants in the
code.
o Use NULL in preference to 0 for a few pointers.
o default to bus timing normal, like we default to bus_width_1.

Add one more debug level.

Improve mmc driver verbose logging.
Make requests logging controllable by hw.mmc.debug sysctl.

Default to normal bus timing mode on SD cards. In practice, most
cards people have today support high speed mode, so the timing field
would be initialized to bus_timing_hs, but there are some slow
cards...

Fix minor style nit for file consistency.

Make the command reporting be under boot verbose.
Also, report a few other things under boot verbose.
Small style nit to make new code look like old code in this file.

Fix copy/paste mistake in variable name. This could lead to using incorrect
bus frequency.

Implement suspend/resume for mmc and mmcsd drivers.
Now it is possible to suspend/resume with inserted and active card.

To reinitialize card on resume and to detect card change while suspended,
implement bus rescan routines. It can also be used by controllers without
card presence detection signals or with multiple cards per slot support.

While there, cleanup msleep() usage. We have no any rights to exit without
"request done" signal from driver as it could lead to modify after free.

Allow card reader bridge driver to report maximum supported transfer size.
sdhci supports up to 65535 blocks transfers, at91_mci - one block.

Enable multiblock operations disabled before to follow at91_mci driver
limitations.

Reviewed by: imp@

Implement BIO_DELETE command with MMC and SD erase commands.

Erase operation gives card's logic information about unused areas to help it
implement wear-leveling with lower overhead comparing to usual writing.
Erase is much faster then write and does not depends on data bus speed.
Also as result of hitting in-card write logic optimizations I have measured
up to 50% performance boost on writing undersized blocks into preerased areas.

At the same time there are strict limitations on size and allignment of erase
operations. We can erase only blocks aligned to the erase sector size and
with size multiple of it. Different cards has different erase sector size
which usually varies from 64KB to 4MB. SD cards actually allow to erase
smaller blocks, but it is much more expensive as it is implemented via
read-erase-write sequence and so not sutable for the BIO_DELETE purposes.

Reviewed by: imp@

style(9): spaces around operators.

SELECT_CARD command with zero RCA deselects all cards and so has no reply.

Give mmcsd driver a bit more information about card. It allows to reorganize
log message in a way a bit more common for disk devices. Also it will allow
mmcsd driver to use MMC/SD specific commands when needed.

Add high capacity MMC cards support.

o Use seprate routines to decode cid and csd for sd and mmc cards. All they
have in common right now is a memset. This saves a parameter to
these routines, as well as a level of indentation.
o Make mmc_get_bits a little clearer... It really only works on 128-bit
registers right now.

Only voltage bits should be zero in send_op_cond argument to ignore busy.

Generic SD Host Controller driver going to be named sdhci.

Fix bit offset in mmc_sd_switch().

Set of mmc layer improvements:
- add MMC support.
- add SDHC support.
- add 4 and 8 bit bus width support.
- add High Speed bus timing support.

Define and use MMC_SECTOR_SIZE.
Make mmc_get_media_size now return an off_t and remove now useless cast.

Make the media size return the block rather than the bytes on the device.

Explicitly set data to NULL rather than relying mmc_wait_for_cmd() to
do it for us. There may be commands we have to wait for that need to
set data.

Submitted by: mav@

Minor style fixes from mav@ (with similar problems fixed where I noticed
them):
#define<tab>
zero memory when we allocate it
Put device name in error message.

Submitted by: mav@

Conform to style(9) for return (foo); The files were a mix before.

Submitted by: mav@

Convert all C++ comments to C style. There's lots of folks that don't
like them and they don't add enough to be worth standing out.

The parameters to the MMCBR_ACQUIRE_HOST and MMCBR_RELEAES_HOST were
the device in question, rather than the bus doing the requesting. Fix
it so that it is the bus.

Submitted by: mav@

Implement power down, and power down the bus on detach.

Submitted by: mav@

Propigate read-only status of cards. Right now it is read only at
device attach time. We may need to read this more often in the
future, but for now simplicity of implementation wins.

Submitted by: mav@

The OCR register defines both acceptable voltage bits, as well as bits
for other things. Mask out the voltage only bits when returning the
Vdd mask for voltage computation.

Submitted by: mav@

Other busses on the system use the official capitalization for the
technology. Make mmc conform to that.

Submitted by: mav@

Fix line continuation whitespace.

Submitted by: mav@

MFp4: When querying the operating condition of SD cards (using the
application specific SEND_OP_COND (CMD55 + ACMD41), go ahead and allow
100 tries. This gives a timeout of a second rather than the ~100ms
the old style produces.

I've had one old 16MB SD card which needs the extra time. I've now
had reports from the field that other cards need this too.

Originally done at BSDcan 2007 while waiting to give my embedding
madness minitalk.

A careful reading of the disclaimer that is required to download the
SD Simplified specification, as well as other SD and SDIO
implemenations I've examined, suggest this disclaimer may be required.
It is unclear to me exactly what the license would be for, or why it
might be required. Err on the side of caution and include this
disclaimer so anybody deploying this code can judge for themselves. I
have no further unformation about the details.

First cut at making detach work. also add sdh as a possible mmc bridge.

Submitted by: Andrea Bittau
(Andrea may have updated patches, but I've tested these)

Preliminary MMC stack. This stack supports SD 1.0 cards only, but
should be easily adapted to SD 2.0 (aka SDHC), SDIO, MMC and MMCplus
cards. At the present time, there's only one bridge driver for the
ARM9 based Atmel AT91RM9200.