This patch converts the drivers in drivers/tty/serial/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jamie Iles <jamie@jamieiles.com>
Cc: Yoichi Yuasa <yuasa@linux-mips.org>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In ancient times it was necessary to manually initialize the bus field of an
spi_driver to spi_bus_type. These days this is done in spi_driver_register(),
so we can drop the manual assignment.
The patch was generated using the following coccinelle semantic patch:
// <smpl>
@@
identifier _driver;
@@
struct spi_driver _driver = {
.driver = {
- .bus = &spi_bus_type,
},
};
// </smpl>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The semantics of UPF_IIR_ONCE (once per serial irq) are only guaranteed
if the kt irq is not shared (once per serial isr in the shared case ==
potentially unwanted reads of the IIR).
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Workaround dropped notifications in the iir register. Prevent reads
coincident with new interrupt notifications by reading the iir at most
once per interrupt.
Reported-by: Nhan H Mai <nhan.h.mai@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is no need to call uart_write_wakeup after each character send.
Once at the end of the write sequence is enough.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The function check_modem_status returns an int currently it
is stored in a char.
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
TTY: ldisc, wait for ldisc infinitely in hangup
TTY: ldisc, move wait idle to caller
TTY: ldisc, allow waiting for ldisc arbitrarily long
Revert "tty/serial: Prevent drop of DCD on suspend for Tegra UARTs"
RS485: fix inconsistencies in the meaning of some variables
pch_uart: Fix DMA resource leak issue
serial,mfd: Fix CMSPAR setup
tty/serial: Prevent drop of DCD on suspend for Tegra UARTs
pch_uart: Change company name OKI SEMICONDUCTOR to LAPIS Semiconductor
pch_uart: Support new device LAPIS Semiconductor ML7831 IOH
pch_uart: Fix hw-flow control issue
tty: hvc_dcc: Fix duplicate character inputs
jsm: Change maintainership
SiRFprimaII is the latest generation application processor from CSR’s
multi-function SoC product family.
The SoC support codes are in arch/arm/mach-prima2 from Linux mainline
3.0.
There are three dedicated UARTs in system. This patch adds basic driver
support for them.
It has used the newest pinmux subsystem from Linus Walleij.
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rong Wang <Rong.Wang@csr.com>
Signed-off-by: Bin Shi <Bin.Shi@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
They were cut&pasted from tty_io. Many of them are not needed in
tty_ldisc.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Instead of the hackish way of counting ptys, let's define a specific
->remove hook both from slave and master. And decrease the count only
for master.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
For /dev/console case, we do not kill all ldisc users. It's due to
redirected_tty_write test in __tty_hangup. In that case there still
might be a process waiting e.g. in n_tty_read for input.
We wait for such processes to disappear. The problem is that we use a
timeout. After this timeout, we continue closing the ldisc and start
freeing tty resources. It obviously leads to crashes when the other
process is woken.
So to fix this, we wait infinitely before reiniting the ldisc. (The
tiocsetd remains untouched -- times out after 5s.)
This is nicely reproducible with this run from shell:
exec 0<>/dev/console 1<>/dev/console 2<>/dev/console
and stopping a getty like:
systemctl stop serial-getty@ttyS0.service
The crash proper may be produced only under load or with constified
timing the same as for 92f6fa09b.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Dmitriy Matrosov <sgf.dma@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It is the only place where reinit is called from. And we really need
to wait for the old ldisc to go once. Actually this is the place where
the waiting originally was (before removed and re-added later).
This will make the fix in the following patch easier to implement.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Dmitriy Matrosov <sgf.dma@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
To fix a nasty bug in ldisc hup vs. reinit we need to wait infinitely
long for ldisc to be gone. So here we add a parameter to
tty_ldisc_wait_idle to allow that.
This is only a preparation for the real fix which is done in the
following patches.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Dmitriy Matrosov <sgf.dma@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit 9636b755da.
It wasn't supposed to be applied, thanks to Doug for letting me know.
Cc: Doug Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Extract ASYNC_INITIALIZED/TTY_IO_ERROR handling from uart_startup.
This will be useful for tty port helpers. These flags are handled
by the helpers instead.
So we create a new function uart_port_startup without touching these
flags there. And we keep uart_startup with the exact behavior as
before. We need that one because we start/stop the device from other
paths than open/close/hangup.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Let's fill the port_ops->shutdown. We will need this for hangup and
close port helpers.
We don't need to touch DTR/RTS registers in uart_port_shutdown. They
are set to off from port_close_start properly already.
Also we don't need to pin the TTY_IO_ERROR bit. This will be done in
close/hangup paths.
We leave uart_shutdown as is, because it is used (and will be) from
several paths now. Like from suspend.
The point is to not touch ASYNC_INITIALIZED bit. It will be set (and
checked) properly by the tty port helpers.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is a preparation for the next patches which will move the stuff
from uart_open and uart_close/hangup here. Then we will use
tty_port_* helpers.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We need to expand uart_get into uart_open. We need it to move on with
conversion to use tty_port_open helper. After we do this, the code
will be much more similar to what tty_port_open does.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It is not used at all, so no need to play any games with that.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Just put a kernel-doc comment to uart_change_pm and uart_insert_char.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
After the previous patches, the code is almost identical. There are
few differences in the helper code:
1) flush_buffer when flow_stopped
* when a user doesn't care about the data, delete it anyways
2) ASYNCB_INITIALIZED test before wait_until_sent_from
* obviously, there is nothing to wait for if the port is dead
3) drain_delay wait
* we don't set drain_delay
So we can use the helper now. It indeed removes a bunch of duplicated
code.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As the tty_port helpers think closing_wait and close_delay are in
jiffies and we want to use the helpers (next patches), we have to
switch the closing_wait and close_delay from ms to jiffies now.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Current ldisc number is passed as a paramneter -- no need to dig it
out of the tty or ldisc. So switch PPS check to that.
No tty callback can be called with port->line higher than TTY driver
num. So remove the check.
This removes some port.tty users.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Viktar Palstsiuk <viktar.palstsiuk@promwad.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are some functions (uart_handle_dcd_change, _handle_cts_change,
_insert_char) which are big enough to not be inlined. So move them
from .h to .c. We need to export them so that modules can actually use
them.
They will be even bigger when we introduce tty refcounting to them.
While at it, cleanup the "Proud member of Uglyhacks'R'US". It means,
define uart_handle_sysrq_char only when SUPPORT_SYSRQ is set.
Otherwise define it as a macro. This is needed for some arm driver
where the second parameter is undefined if expanded.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Making SERIAL_OMAP depend on ARCH_OMAP2PLUS instead of
oring with ARCH2/3/4.
Acked-by: Felipe Balbi <balbi@ti.com>
Suggested-by: Sricharan R <r.sricharan@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is no need to taint the tty_release code with paranoia
checking. So move it out of line to a separate function. Making thus
tty_release more readable.
[v2] don't introduce a hard to reproduce use after free (scheduled work would
need to preempt the current thread)
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The labels express more the nature of the decision tree. We returned
from each if with a driver. Now we do this at the end of the function
and the code flow is clear.
While at it, remove an obsolete comment (we already take the
reference).
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move them to the end of the function and use gotos as usual.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The error handling in tty_open became unbearable. There were many
errors fixed recently. Extract the tty driver lookup from tty_open to
a separate function. This reduces the fail paths significantly and
makes tty_open more readable.
In the next patch we will move the fail path handling to the end of
the function.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This one is special to others (done in the next patch). We have the
tty directly, not its driver and index. So this will reside in a
separation function. In the next patch, the rest will be moved to
another function.
So now we set neither driver nor index. Hence we need to init driver
and check whether we are supposed to put a ref of that.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move it to the only branch where tty_pgrp may be set. This is only a
cleanup which allows having tty_pgrp defined at that place.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add console support to pch_uart. To enable append e.g.
console=ttyPCH0,115200 to your kernel command line.
This is not expected work on CM-iTC boards due to their having a different
clock.
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add support to specify which HSU port to use as an early console. This can
be selected by passing "earlyprintk=hsu<n>" on the kernel command line. By
default port 0 is still used.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
wait_event_timeout always return value >= 0
remove the unnecessary ret < 0 check
Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The crisv10.c and the atmel_serial.c serial drivers intepret the fields of the
serial_rs485 structure in a different way.
In particular, crisv10.c uses SER_RS485_RTS_AFTER_SEND and
SER_RS485_RTS_ON_SEND for the voltage of the RTS pin; atmel_serial.c,
instead, uses these values to know if a delay must be set before and
after sending. This patch makes the usage of these variables consistent
across all drivers and fixes the Documentation as well.
From now on, SER_RS485_RTS_AFTER_SEND and SER_RS485_RTS_ON_SEND will be
used to set the voltage of the RTS pin (as in the crisv10.c driver); the
delay will be understood by looking only at the value of
delay_rts_before_send and delay_rts_after_send.
Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Signed-off-by: Darron Black <darron@griffin.net>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Changing UART mode PIO->DMA->PIO->DMA like below, pch_uart driver can't get
DMA channel resource.
setserial /dev/ttyPCH0 ^low_latency
setserial /dev/ttyPCH0 low_latency
CAUSE:
Changing mode using setserial command, ".startup" function which gets DMA
channel is called before ".verify_port" function which sets
dma-flag(use_dma/use_dma_flag) as 1.
PIO->DMA
.startup: Since dma-flag is 0, DMA channel is not requested.
.verify_port: dma-flag is set as 1.
.shutdown: N/A
DMA->PIO
.startup: Since dma-flag is 1, DMA channel is requested.
.verify_port: dma-flag is set as 0.
.shutdown: Since dma-flag is 0, DMA channel is not released.
This means DMA channel resource leak occurs.
Next time, this driver can't get DMA channel resource forever.
MODIFICATION:
Currently, when release DMA channel resource, this driver checks dma-flag.
However, this specification occurs the above issue.
This driver must check whether dma_request_channel is executed or not.
The values are saved in private data variable "chan_tx/chan_tx".
These variables mean if the value is NULL, DMA channel is not requested,
if not NULL, DMA channel is requested.
This patch fixes the issue.
Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is referenced the wrong way. Mika Westerberg added some checks to the
tty to support multiple console, but the real problem is simply referencing the
termios object via the wrong path.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On Tegra UARTs (except UART1), the DTR / DCD / DSR lines are not
externally accessible. Instead, the DTR line internally appears to be
looped back to be the input to the DCD and DSR lines. The net effect
of this is that when we drop DTR (like when we suspend), we'll see DCD
drop too. ...and when we see DCD drop, we treat that as a hangup.
In order to prevent this hangup from occurring at every sleep, we need
to force DTR to remain high on Tegra UARTs.
This patch uses the mcr_mask / mcr_force fields, which were originally
added for the kludge ALPHA_KLUDGE_MCR. Using these fields does not
prevent us from removing ALPHA_KLUDGE_MCR--we can just remove the "if"
tests I have added and always init mcr_mask / mcr_force from the
serial8250_config.
NOTE: If we have people that are using UARTA on a Tegra and need to
control DTR, we'll need to either add a separate port type for UARTA
or we'll need to add some tegra-specific code to detect whether the
DTR needs to be left high.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On October 1 in 2011,
OKI SEMICONDUCTOR Co., Ltd. changed the company name in to LAPIS Semiconductor Co., Ltd.
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.lapis-semi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Using hardware flow control,
currently, register of the control-bit(AFE) is not set.
This patch fixes the issue.
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.lapis-semi.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Reading from the DCC grabs a character from the buffer and
clears the status bit. Since this is a context-changing
operation, instructions following the character read that rely on
the status bit being accurate need to be synchronized with an
ISB.
In this case, the status bit check needs to execute after the
character read otherwise we run the risk of reading the character
and checking the status bit before the read can clear the status
bit in the first place. When this happens, the user will see the
same character they typed twice, instead of once.
Add an ISB after the read and the write, so that the status check
is synchronized with the read/write operations.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Alek Du reported that the code erroneously applies time to jiffies
conversions twice to the t1 and t2 values. In normal use on a modem link
this cases no visible problem but on a slower link it will break as with
HZ=1000 as is typical we are running t1/t2 ten times too fast.
Alek's original patch removed the conversion from the timer setting but we
in fact have to be more careful as the contents of t1/t2 are visible via
the device API and we thus need to correct the constants.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 361162459f.
It causes an infinite loop when booting Linux under Xen, as so:
[ 2.382984] console [hvc0] enabled
[ 2.382984] console [hvc0] enabled
[ 2.382984] console [hvc0] enabled
...
as reported by Konrad Rzeszutek Wilk. And Rusty reports the same for
lguest. He goes on to say:
"This is not a concurrency problem: the issue seems to be that
calling register_console() twice on the same struct console is a bad
idea."
and Greg says he'll fix it up properly at some point later. Revert for now.
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reported-by: Rusty Russell <rusty@ozlabs.org>
Requested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Miche Baker-Harvey <miche@google.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix building following build error:
drivers/tty/hvc/hvc_opal.c:244:12: error: 'THIS_MODULE' undeclared here (not in a function)
Signed-off-by: Michael Neuling <mikey@neuling.org>
[ New file from powerpc tree not following the new rules from the
module.h split, both of which were merged today. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h