The interrupt polling frequency is a compromise between power usage and
interrupt latency. Unfortunately, it affects throughput rather severely
for devices which require an interrupt for every chunk of data.
By making the polling frequency adaptive, we get better throughput with
those devices without sacficing too much power. Polling will quickly
increase when there is an actual interrupt, and slowly fall back to the
idle frequency when the interrupts stop coming.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Add a led trigger for each host controller that indicates if there
is a request active on the controller.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
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>
Increase delay for power up in order to support some slower boards.
Also add some comments about why the delays are there.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Add sdio_f0_readb() and sdio_f0_writeb() functions to reading and
writing function 0 registers. Writes outside the vendor specific CCCR
registers (0xF0 - 0xFF) are not permitted.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
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>
Extend sdio_readsb(), sdio_writesb(), sdio_memcpy_fromio(), and
sdio_memcpy_toio() to handle any length of buffer by splitting the transfer
into several IO_RW_EXTENDED commands. Typically, a transfer would be split
into a single block mode transfer followed by a byte mode transfer for the
remainder but we also handle lack of block mode support and the block size
being greater than 512 (the maximum byte mode transfer size).
host->max_seg_size <= host->max_req_size so there's no need to check both
when determining the maximum data size for a single command.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Before a driver is probed, set the function's block size to the default so the
driver is sure the block size is something sensible and it needn't explicitly
set it.
The default block size is the largest that's supported by both the card and
the host, with a maximum of 512 to ensure aribitrarily sized transfer use the
optimal (least) number of commands.
See http://lkml.org/lkml/2007/8/7/150 for reasons for the block size choice.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
On Wed, Jul 25, 2007 at 04:03:04AM -0700, Andrew Morton wrote:
>...
> Changes since 2.6.22-rc6-mm1:
>...
> git-mmc.patch
>...
> git trees
>...
sdio_dev_attrs[] can become static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Support the multi-byte transfer operation, including handlers for
common operations like writel()/readl().
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
It is sometimes necessary to give up on trying to claim the host lock,
especially if that happens in a thread that has to be stopped.
While at it, fix the description for mmc_claim_host() which was wrong.
Signed-off-by: Nicolas Pitre <npitre@mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The problem is that the sdio_bus must be registered before any SDIO
drivers are registered against it otherwise the kernel sulks. Because
the sdio_bus registration happens through module_init (equivalent to
device_initcall), then any SDIO
drivers linked before the SDIO core code in the kernel will be initialized
first.
Upcoming SDIO function drivers are likely to be located outside the
drivers/mmc directory as it is common practice to group drivers according
to their function rather than the bus they use. SDIO drivers are therefore
likely to appear at random location in the kernel link.
To make sure the sdio_bus is always initialized before any SDIO drivers,
let's move the MMC init to the subsys_initcall level.
Signed-off-by: Nicolas Pitre <npitre@mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Add a more clean separation between global, common CIS information
and the function specific one as we need the common information in
places where no specific function is specified.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This way those tuples that the core cares about are consumed by the core
code, and tuples that only function drivers might make sense of are
available to drivers.
Signed-off-by: Nicolas Pitre <npitre@mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Like many other buses, the devices (functions) on the SDIO bus
must be enabled before they can be used. Add functions that allow
drivers to do so.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The write parameter in mmc_set_data_timeout() is redundant as the
data structure contains information about the direction of the
transfer.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This patch makes the following needlessly global functions static:
- sd_ops.c: mmc_app_cmd()
- core.c: __mmc_release_bus()
- core.c: mmc_start_request()
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Make sure that the debugging output in the core is complete.
This should allow us to clean up all the extra debug output
that each and every other host driver seems to contain.
Signed-off-by: Pierre 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: Pierre 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: Pierre Ossman <drzeus@drzeus.cx>
In the normal case, the host lock can be claimed directly.
When it cannot, the caller will sleep. Make sure we don't
have any latent bugs by always calling might_sleep().
Signed-off-by: Pierre 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: Pierre Ossman <drzeus@drzeus.cx>
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>
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>
As mmc_detect_change() can be called from irq context, using
claim (which can sleep) is inherently unsafe. Use the host
spinlock instead, which also is faster.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Change Kconfig objects from "menu, config" into "menuconfig" so
that the user can disable the whole feature without having to
enter the menu first.
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Pierre 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: Pierre 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: Philip Langdale <philipl@overt.org>
Signed-off-by: Pierre 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: Pierre Ossman <drzeus@drzeus.cx>
Move protocol operations and definitions into their own files
in an effort to separate protocol handling and bus
arbitration more clearly.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Pierre Ossman