The PXA has two transmit FIFOes, each32 byte deep. when one FIFO is
full and the other one has been transmitted, they are automatically
swapped and DMA is triggered for another 32 byte burst. However, when
there is less than 32 bytes left to send, the FIFO swap has to be done
manually. This is required for some SDIO transfers which are not
required to be multiples of 32 bytes.
A DMA completion interrupt is set for each descriptor which length isn't
a multiple of 32 in order to force the FIFO swap. While at it, the DMA
interrupt handler has been made a bit more resilient against errors.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Currently we print a message about some bad states wrt function IRQ
handlers but return 0 from process_sdio_pending_irqs() nevertheless.
This can lead to an infinite loop as nothing might have cleared the
condition for the pending card interrupt from the host controller by
the time host->ops->enable_sdio_irq(host, 1) is called.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
If func is actually null we won't get much from sdio_func_id(func).
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The forcedma and nodma module parameters can be replaced with the quirks
parameter, so remove the redundancy.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some controllers like ENE712 can't work properly with DMA mode,
add this quirk to force these kinds of HW work with PIO mode
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Many host controllers don't fully follow the PCI spec to claim
whether they support DMA in PCI class register. Leave the driver
to judge it from the Capability register, quirks and module parameter
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Thanks to Matt Domsch and Rezwanul Kabir at Dell, we know how to disable the
MMC controller on the multi-function Ricoh R5C832. The MMC controller needs
to be disabled or it will steal MMC cards from the SD controller where they
would otherwise be supported by the Linux SDHCI driver.
Signed-off-by: Philipl Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
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>
Again, only available from PXA27x.
Signed-off-by: Bridge Wu <mingqiao.wu@gmail.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
From PXA27x, it is possible to do 4-bit data transfers.
Signed-off-by: Bridge Wu <mingqiao.wu@gmail.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
From PXA27x, it is possible to do 2048-byte block transfers.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Pending interrupts should be determined from both I_REG and I_MASK
registers.
Signed-off-by: Bridge Wu <mingqiao.wu@gmail.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The patch enables to define MMC host get_ro() method through platform data.
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
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>
This is the latest version of the MMC-over-SPI support. It works
on 2.6.23-rc2 plus git-mmc (from rc1-mm2), along with the preceding
patches which teach the rest of the MMC stack about SPI.
The main issue of note is that sometimes cards need to be power cycled
to recover after certain faults. Also, it may sometimes be necessary
to disable CRCs. ("modprobe mmc_core use_spi_crc=n")
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: mikael.starvik@axis.com,
Cc: Hans-Peter Nilsson <hp@axis.com>
Cc: Jan Nikitenko <jan.nikitenko@gmail.com>
Cc: Mike Lavender <mike@steroidmicros.com>
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>
Teaching the MMC/SD block card driver about SPI.
- Provide the SPI response type flags with each request issued.
- Understand that multiblock SPI writes don't use STOP_TRANSMISSION.
- Correct check for APP_CMD failure.
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>
In a few places, sdio_uart_irq() is called directly instead of waiting
for the actual interrupt to be raised and the SDIO IRQ thread scheduled
in order to reduce latency. However, some interaction with the tty core
may end up calling us back (serial echo, flow control, etc.) creating
two issues:
- the host lock gets claimed twice from the same thread causing a
deadlock;
- the same direct calls to sdio_uart_irq() may be performed causing
unexpected reentrancy into the IRQ handler.
This patch handles both of those issues.
Signed-off-by: Nicolas Pitre <npitre@mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Note that the default baudrate is 4800 instead of 9600 as a convenience
because that's what GPS devices want which is still the main use for
this driver.
Signed-off-by: Nicolas Pitre <npitre@mvista.com>
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>
This mimics what the serial_core does. Useful for diagnostics.
Signed-off-by: Nicolas Pitre <npitre@mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This currently only accepts the GPS class since that's all I have for
testing. Tested with a Matsushita GPS and gpsd version 2.34.
Signed-off-by: Nicolas Pitre <npitre@mvista.com>
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>
This kind of transfer is not supported, so don't advertise it and make it
fail early.
Signed-off-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The MMC_DATA_MULTI flag never had a proper definition of what it
means, so remove it and let the drivers check the block count in
the request.
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 fixes a bug in AT91 mmc host driver, that enables the wakeup
from suspend on card detection pin even if the card detect pin is not
available (==0). If not card detection pin is defined, IRQ0 == FIQ gets
enabled and if some activity is present on that pin, the system gets a
FIQ request, that causes a crash.
Signed-off-by: Anti Sullin <anti.sullin@artecdesign.ee>
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
It is fully legal for a controller to start issuing data related
interrupts before it has signalled that the command has completed.
Make sure the driver actually can handle this.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some SDHC cards report an invalid maximum block size, in these cases
assume they support block sizes up to 512 bytes instead of returning
an error.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The block count register shouldn't be trusted for single block transfers,
so avoid using it completely when calculating transferred bytes.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some cleanup with whitespace/tab at the end of lines.
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Reorganize the code that initializes mmc_block's bounce buffer in
order to avoid warnings when MMC_BLOCK_BOUNCE isn't used.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This patch fixes the following section mismatch warnings
...
WARNING: vmlinux.o(.init.text+0x29d40): Section mismatch: reference to .exit.text:wbsd_release_resources (between 'wbsd_init' and 'wbsd_probe')
WARNING: vmlinux.o(.init.text+0x29d49): Section mismatch: reference to .exit.text:wbsd_free_mmc (between 'wbsd_init' and 'wbsd_probe')
WARNING: vmlinux.o(.init.text+0x29f28): Section mismatch: reference to .exit.text:wbsd_free_mmc (between 'wbsd_init' and 'wbsd_probe')
...
Signed-off-by: Gabriel Craciunescu <nix.or.die@googlemail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
drivers/mmc/core/: make 3 functions static
mmc: add missing printk levels
mmc: remove redundant debug information from sdhci and wbsd
mmc: proper debugging output in core
mmc: be more verbose about card insertions/removal
mmc: Don't hold lock when releasing an added card
mmc: add a might_sleep() to mmc_claim_host()
mmc: update kerneldoc
mmc: update header file paths
sdhci: add support to ENE-CB714
mmc: check error bits before command completion
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>
Added its pci_id and implemented a quirk for it because this
controller needs to reset cmd and data when setting ios.
Signed-off-by: Leandro Dorileo <dorileo@ossystems.com.br>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some controllers signal "command complete" even on failures (which
they are allowed to do according to the spec). Make sure we check
the error bits first so we don't get any false positives.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some of the code has been gradually transitioned to using the proper
struct request_queue, but there's lots left. So do a full sweet of
the kernel and get rid of this typedef and replace its uses with
the proper type.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The controller has a bit indicating that one of the higher bits (the
error bits) are set. A previous bug caused this bit to be masked, but
since that bug has been fixed we have to clear it explicictly.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This piece of code enable the system to be wake-up by a card insertion or removal.
Signed-off-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Transform some calls to kmalloc/memset to a single kzalloc (or kcalloc).
Here is a short excerpt of the semantic patch performing
this transformation:
@@
type T2;
expression x;
identifier f,fld;
expression E;
expression E1,E2;
expression e1,e2,e3,y;
statement S;
@@
x =
- kmalloc
+ kzalloc
(E1,E2)
... when != \(x->fld=E;\|y=f(...,x,...);\|f(...,x,...);\|x=E;\|while(...) S\|for(e1;e2;e3) S\)
- memset((T2)x,0,E1);
@@
expression E1,E2,E3;
@@
- kzalloc(E1 * E2,E3)
+ kcalloc(E1,E2,E3)
[akpm@linux-foundation.org: get kcalloc args the right way around]
Signed-off-by: Yoann Padioleau <padator@wanadoo.fr>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Bryan Wu <bryan.wu@analog.com>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Dave Airlie <airlied@linux.ie>
Acked-by: Roland Dreier <rolandd@cisco.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Acked-by: Pierre Ossman <drzeus-list@drzeus.cx>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Greg KH <greg@kroah.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves. This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.
It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.
The patch causes all kernel threads to be nonfreezable by default (ie. to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE. It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear. Additionally, it updates documentation to
describe the freezing of tasks more accurately.
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (50 commits)
[ARM] sa1100: remove boot time RTC initialisation
[ARM] sa1100: stop doing our own rtc management over suspend
[ARM] 4474/1: Do not check the PSR_F_BIT in valid_user_regs
[ARM] 4473/2: Take the HWCAP definitions out of the elf.h file
[ARM] pxa: move platform devices to separate header file
[ARM] pxa: move device registration into CPU-specific file
[ARM] pxa: remove boot time RTC initialisation
[ARM] pxa: stop doing our own rtc management over suspend
[ARM] 4451/1: pxa: make dma.c generic and remove cpu specific dma code
[ARM] 4450/1: pxa: add pxa25x_init_irq() and pxa27x_init_irq()
[ARM] 4440/1: PXA: enable the checking of ICIP2 for IRQs
[ARM] 4438/1: PXA: remove #ifdef .. #endif from pxa_gpio_demux_handler()
[ARM] 4437/1: PXA: move the GPIO IRQ initialization code to pxa_init_irq_gpio()
[ARM] 4436/1: PXA: move low IRQ initialization code to pxa_init_irq_low()
[ARM] 4435/1: PXA: remove PXA_INTERNAL_IRQS
[ARM] 4434/1: PXA: remove PXA_IRQ_SKIP
[ARM] pxa: Fix PXA27x suspend type validation, remove pxa_pm_prepare()
[ARM] pxa: move pm_ops structure into CPU specific files
[ARM] pxa: introduce cpu_is_pxaXXX macros
[ARM] pxa: remove MMC register defines from pxa-regs.h
...
pxamci.h redefines the MMC registers differently so they can be used
with ioremap. Remove the incompatible definitions from pxa-regs.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fixes hanging using multi block operations (seen during CMD25).
Follows closely the datasheet flowcharts.
This piece of code handles better big file writing. I had to take care
of the notbusy signal during write (at91_mci_handle_cmdrdy function) and
to rearrange the AT91_MCI_ENDRX and AT91_MCI_RXBUFF flag usage.
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Typo fix in at91_mci driver : standardized the typo
(at91_mci everywhere)
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Whenever a power interrupt is signaled it is also reported as an unexpected
one. All other unexpected interrupts get lost. Cause is a not inversed
bitmask to remove power interrupts from the status.
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
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>
