Commit graph

20 commits

Author SHA1 Message Date
Deepak Saxena
8769392b19 MMC: Trivial comment cleanup
Make the variable name in the comments match the actual name
of the variable.

Signed-off-by: Deepak Saxena <dsaxena@laptop.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2008-07-15 14:14:41 +02:00
Anton Vorontsov
08f80bb519 mmc: change .get_ro() callback semantics
Now get_ro() callback must return 0/1 values for its logical states, and
negative errno values in case of error. If particular host instance doesn't
support RO/WP switch, it should return -ENOSYS.

This patch changes some hosts in two ways:

1. Now functions should be smart to not return negative values in
   "RO asserted" case (particularly gpio_ calls could return negative
   values for the outermost GPIOs).

   Also, board code usually passes get_ro() callbacks that directly return
   gpioreg & bit result, so at91_mci, imxmmc, pxamci and mmc_spi's get_ro()
   handlers need take special care when returning platform's values to the
   mmc core.

2. In case of host instance didn't implement get_ro() callback, it should
   really return -ENOSYS and let the mmc core decide what to do about it
   (mmc core thinks the same way as the hosts, so it isn't functional
   change).

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2008-07-15 14:14:41 +02:00
Pierre Ossman
51ec92e295 mmc: use sysfs groups to handle conditional attributes
Suppressing uevents turned out to be a bad idea as it screws up the
order of events, making user space very confused. Change the system to
use sysfs groups instead.

This is a regression that, for some odd reason, has gone unnoticed for
some time. It confuses hal so that the block devices (which have the
mmc device as a parent) are not registered. End result being that
desktop magic when cards are inserted won't work.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-22 17:02:20 -07:00
David Brownell
af51715079 MMC core learns about SPI
Teach the MMC/SD/SDIO core about using SPI mode.

 - Use mmc_host_is_spi() so enumeration works through SPI signaling
   and protocols, not just the native versions.

 - Provide the SPI response type flags with each request issued,
   including requests from the new lock/unlock code.

 - Understand that cmd->resp[0] and mmc_get_status() results for SPI
   return different values than for "native" MMC/SD protocol; this
   affects resetting, checking card lock status, and some others.

 - Understand that some commands act a bit differently ... notably:
     * OP_COND command doesn't return the OCR
     * APP_CMD status doesn't have an R1_APP_CMD analogue

Those changes required some new and updated primitives:

 - Provide utilities to access two SPI-only requests, and one
   request that wasn't previously needed:
     * mmc_spi_read_ocr() ... SPI only
     * mmc_spi_set_crc() ... SPI only (override by module parm)
     * mmc_send_cid() ... for use without broadcast mode

 - Updated internal routines:
     * Previous mmc_send_csd() modified into mmc_send_cxd_native();
       it uses native "R2" responses, which include 16 bytes of data.
     * Previous mmc_send_ext_csd() becomes new mmc_send_cxd_data()
       helper for command-and-data access
     * Bugfix to that mmc_send_cxd_data() code:  dma-to-stack is
       unsafe/nonportable, so kmalloc a bounce buffer instead.

 - Modified mmc_send_ext_csd() now uses mmc_send_cxd_data() helper

 - Modified mmc_send_csd(), and new mmc_spi_send_cid(), routines use
   those helper routines based on whether they're native or SPI

The newest categories of cards supported by the MMC stack aren't expected
to work yet with SPI:  MMC or SD cards with over 4GB data, and SDIO.
All those cards support SPI mode, so eventually they should work too.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-09-23 21:51:30 +02:00
Pierre Ossman
d84075c8ae mmc: replace BUG_ON with WARN_ON
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: Pierre Ossman <drzeus@drzeus.cx>
2007-09-23 21:23:07 +02:00
Pierre Ossman
adf66a0dc5 mmc: improve error code feedback
Now that we use "normal" error codes, improve the reporting and response
to error codes in the core.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-09-23 09:14:43 +02:00
Pierre Ossman
17b0429dde mmc: remove custom error codes
Convert the MMC layer to use standard error codes and not its own,
incompatible values.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-09-23 08:46:48 +02:00
Pierre Ossman
facba9179e mmc: add missing printk levels
Some printk:s were missing an explicit level.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-07-26 02:05:49 +02:00
Pierre Ossman
109b5bed18 mmc: be more verbose about card insertions/removal
Let the user know that the kernel actually detected the card
by printing some basic information in dmesg.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-07-26 02:05:04 +02:00
Pierre Ossman
2986d0bf23 mmc: Don't hold lock when releasing an added card
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: Pierre Ossman <drzeus@drzeus.cx>
2007-07-26 01:54:06 +02:00
Pierre Ossman
70f10482c6 mmc: update header file paths
Make sure all headers in the files reflect their true position
in the tree.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-07-26 01:53:31 +02:00
Pierre Ossman
4101c16a91 mmc: refactor bus operations
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: Pierre Ossman <drzeus@drzeus.cx>
2007-07-09 21:27:56 +02:00
Pierre Ossman
c3bff2ec10 mmc: get back read-only switch function
Somehow the code to read the read-only switch of SD cards got lost
in the reorganisation.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-06-13 19:11:20 +02:00
Pierre Ossman
3373c0ae6a mmc: don't call switch on old cards
Make sure we don't call the switch function on cards too old to
support it. They should just ignore it, but some have been reported
to lock up instead.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-06-07 09:25:58 +02:00
Pierre Ossman
71651297a4 mmc: fix broken if clause
Fix a broken if clause which was causing SD cards to go into
4-bit mode even if the host did not support it.

(Reported by David Brownell and Marc Pignat)

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-06-07 09:25:54 +02:00
Pierre Ossman
bd76631261 mmc: remove old card states
Remove card states that no longer make any sense.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01 16:11:57 +02:00
Pierre Ossman
6abaa0c9fe mmc: support unsafe resume of cards
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: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01 16:00:02 +02:00
Pierre Ossman
1addfcdbe4 mmc: break apart switch function
Break apart the SD switch function into one that reads the capabilities
and one that acts on them.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01 14:46:08 +02:00
Philip Langdale
55556da012 MMC: Fix handling of low-voltage cards
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: Philip Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01 14:14:50 +02:00
Pierre Ossman
7ea239d9e6 mmc: add bus handler
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: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01 13:41:06 +02:00