Replace all cases of BUG_ON with WARN_ON where there is a chance
(with varying degrees of slim) that the kernel can continue without
incidence.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Some printk:s were missing an explicit level.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Make sure we do not try to parse a structure we do not
understand.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Now that we use "normal" error codes, improve the reporting and response
to error codes in the core.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Convert the MMC layer to use standard error codes and not its own,
incompatible values.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Some printk:s were missing an explicit level.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Let the user know that the kernel actually detected the card
by printing some basic information in dmesg.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

When the card has been added to the device model, it might be bound
to a card driver. Therefore, we have to release the host lock when
trying to remove it as we otherwise might deadlock with the driver.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Make sure all headers in the files reflect their true position
in the tree.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Move bus operations to its own file for the sake of clarity. Also
delegate sysfs attributes to bus handlers in preparation for other
more exotic types.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Remove card states that no longer make any sense.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Since many have the system root on MMC/SD we must allow some foot
shooting when it comes to resume.

We cannot detect if a card is removed and reinserted during suspend,
so the safe approach would be to assume it was, avoiding potential
filesystem corruption. This will of course not work if you cannot
release the card before suspend.

This commit adds a compile time option that makes the MMC layer
assume the card wasn't touched if it is redetected upon resume.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Separate the reading and decoding of the EXT_CSD register with the
actions taken on it.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Fix handling of low voltage MMC cards.

The latest MMC and SD specs both agree that support for
low-voltage operations is indicated by bit 7 in the OCR.
The MMC spec states that the low voltage range is
1.65-1.95V while the SD spec leaves the actual voltage
range undefined - meaning that there is still no such
thing as a low voltage SD card.

However, an old Sandisk spec implied that bits 7.0
represented voltages below 2.0V in 1V or 0.5V increments,
and the code was accordingly written with that expectation.

This confusion meant that host drivers attempting to support
the typical low voltage (1.8V) would set the wrong bits in
the host OCR mask (usually bits 5 and/or 6) resulting in the
the low voltage mode never being used.

This change corrects the low voltage range and adds sanity
checks on the reserved bits (0-6) and for SD cards that
claim to support low-voltage operations.
Signed-off-by: NPhilip Langdale <philipl@overt.org>
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Delegate protocol handling to "bus handlers". This allows the core to
just handle the task of arbitrating the bus. Initialisation and
pampering of cards is now done by the different bus handlers.

This design also allows MMC and SD (and later SDIO) to be more cleanly
separated, allowing easier maintenance.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>