Commit Graph

26 Commits

Author SHA1 Message Date
Peter Ujfalusi eda97cb095 dmaengine: of-dma: router_xlate to return -EPROBE_DEFER if controller is not yet available
If the router_xlate can not find the controller in the available DMA
devices then it should return with -EPORBE_DEFER in a same way as the
of_dma_request_slave_channel() does.

The issue can be reproduced if the event router is registered before the
DMA controller itself and a driver would request for a channel before the
controller is registered.
In of_dma_request_slave_channel():
1. of_dma_find_controller() would find the dma_router
2. ofdma->of_dma_xlate() would fail and returned NULL
3. -ENODEV is returned as error code

with this patch we would return in this case the correct -EPROBE_DEFER and
the client can try to request the channel later.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20210717190021.21897-1-peter.ujfalusi@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-07-28 12:54:50 +05:30
Peter Ujfalusi 4f910c035f dmaengine: of-dma: Add support for optional router configuration callback
Additional configuration for the DMA event router might be needed for a
channel which can not be done during device_alloc_chan_resources callback
since the router information is not yet present for the drivers.

If there is a need for additional configuration for the channel if DMA
router is in use, then the driver can implement the device_router_config
callback.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20201208090440.31792-8-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-12-11 21:20:08 +05:30
Peter Ujfalusi 5b2aa9f918 dmaengine: of-dma: Fix of_dma_router_xlate's of_dma_xlate handling
of_dma_xlate callback can return ERR_PTR as well NULL in case of failure.

If error code is returned (not NULL) then the route should be released and
the router should not be registered for the channel.

Fixes: 56f13c0d95 ("dmaengine: of_dma: Support for DMA routers")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200806104928.25975-1-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-08-17 11:14:28 +05:30
Lee Jones 7d8c91487f dmaengine: of-dma: Fix misspellings/formatting issues in some function headers
Fixes the following W=1 kernel build warning(s):

 drivers/dma/of-dma.c:57: warning: Function parameter or member 'ofdma' not described in 'of_dma_router_xlate'
 drivers/dma/of-dma.c:57: warning: Excess function parameter 'of_dma' description in 'of_dma_router_xlate'
 drivers/dma/of-dma.c:107: warning: Function parameter or member 'data' not described in 'of_dma_controller_register'
 drivers/dma/of-dma.c:308: warning: Function parameter or member 'ofdma' not described in 'of_dma_simple_xlate'
 drivers/dma/of-dma.c:308: warning: Excess function parameter 'of_dma' description in 'of_dma_simple_xlate'
 drivers/dma/of-dma.c:338: warning: Function parameter or member 'ofdma' not described in 'of_dma_xlate_by_chan_id'
 drivers/dma/of-dma.c:338: warning: Excess function parameter 'of_dma' description in 'of_dma_xlate_by_chan_id'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200714111546.1755231-3-lee.jones@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-07-15 17:50:46 +05:30
Geert Uytterhoeven c3c431de99 dmaengine: Move dma_get_{,any_}slave_channel() to private dmaengine.h
The functions dma_get_slave_channel() and dma_get_any_slave_channel()
are called from DMA engine drivers only.  Hence move their declarations
from the public header file <linux/dmaengine.h> to the private header
file drivers/dma/dmaengine.h.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200121093311.28639-4-geert+renesas@glider.be
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-01-21 15:05:29 +05:30
Linus Torvalds 47ebe00b68 dmaengine updates for v5.3-rc1
- Add support in dmaengine core to do device node checks for DT devices and
    update bunch of drivers to use that and remove open coding from drivers
  - New driver/driver support for new hardware, namely:
    - MediaTek UART APDMA
    - Freescale i.mx7ulp edma2
    - Synopsys eDMA IP core version 0
    - Allwinner H6 DMA
  - Updates to axi-dma and support for interleaved cyclic transfers
  - Greg's debugfs return value check removals on drivers
  - Updates to stm32-dma, hsu, dw, pl330, tegra drivers
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Merge tag 'dmaengine-5.3-rc1' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine updates from Vinod Koul:

 - Add support in dmaengine core to do device node checks for DT devices
   and update bunch of drivers to use that and remove open coding from
   drivers

 - New driver/driver support for new hardware, namely:
     - MediaTek UART APDMA
     - Freescale i.mx7ulp edma2
     - Synopsys eDMA IP core version 0
     - Allwinner H6 DMA

 - Updates to axi-dma and support for interleaved cyclic transfers

 - Greg's debugfs return value check removals on drivers

 - Updates to stm32-dma, hsu, dw, pl330, tegra drivers

* tag 'dmaengine-5.3-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (68 commits)
  dmaengine: Revert "dmaengine: fsl-edma: add i.mx7ulp edma2 version support"
  dmaengine: at_xdmac: check for non-empty xfers_list before invoking callback
  Documentation: dmaengine: clean up description of dmatest usage
  dmaengine: tegra210-adma: remove PM_CLK dependency
  dmaengine: fsl-edma: add i.mx7ulp edma2 version support
  dt-bindings: dma: fsl-edma: add new i.mx7ulp-edma
  dmaengine: fsl-edma-common: version check for v2 instead
  dmaengine: fsl-edma-common: move dmamux register to another single function
  dmaengine: fsl-edma: add drvdata for fsl-edma
  dmaengine: Revert "dmaengine: fsl-edma: support little endian for edma driver"
  dmaengine: rcar-dmac: Reject zero-length slave DMA requests
  dmaengine: dw: Enable iDMA 32-bit on Intel Elkhart Lake
  dmaengine: dw-edma: fix semicolon.cocci warnings
  dmaengine: sh: usb-dmac: Use [] to denote a flexible array member
  dmaengine: dmatest: timeout value of -1 should specify infinite wait
  dmaengine: dw: Distinguish ->remove() between DW and iDMA 32-bit
  dmaengine: fsl-edma: support little endian for edma driver
  dmaengine: hsu: Revert "set HSU_CH_MTSR to memory width"
  dmagengine: pl330: add code to get reset property
  dt-bindings: pl330: document the optional resets property
  ...
2019-07-17 09:55:43 -07:00
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Baolin Wang f5151311c3 dmaengine: Add matching device node validation in __dma_request_channel()
When user try to request one DMA channel by __dma_request_channel(), it won't
validate if it is the correct DMA device to request, that will lead each DMA
engine driver to validate the correct device node in their filter function
if it is necessary.

Thus we can add the matching device node validation in the DMA engine core,
to remove all of device node validation in the drivers.

Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-05-27 11:23:52 +05:30
Rob Herring c6c93048ba dmaengine: Convert to using %pOF instead of full_name
Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-07-19 09:30:44 +05:30
Niklas Söderlund 20ea6be6bf dmaengine: of_dma: approximate an average distribution
Currently the following DT description would result in dmac0 always
being tried first and dmac1 second if dmac0 was unavailable. This
results in heavier use of dmac0 then of dmac1. This patch adds an
approximate average distribution over the two nodes lessening the load
of anyone of them.

   i2c6: i2c@e60b0000 {
           ...
           dmas = <&dmac0 0x77>, <&dmac0 0x78>,
                  <&dmac1 0x77>, <&dmac1 0x78>;
           dma-names = "tx", "rx", "tx", "rx";
           ...
   };

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-05-14 13:34:10 +05:30
Peter Ujfalusi 56f13c0d95 dmaengine: of_dma: Support for DMA routers
DMA routers are transparent devices used to mux DMA requests from
peripherals to DMA controllers. They are used when the SoC integrates more
devices with DMA requests then their controller can handle.
DRA7x is one example of such SoC, where the sDMA can hanlde 128 DMA request
lines, but in SoC level it has 205 DMA requests.

The of_dma_router will be registered as of_dma_controller with special
xlate function and additional parameters. The driver for the router is
responsible to craft the dma_spec (in the of_dma_route_allocate callback)
which can be used to requests a DMA channel from the real DMA controller.
This way the router can be transparent for the system while remaining generic
enough to be used in different environments.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-05-09 17:11:25 +05:30
Kuninori Morimoto 0aed112443 dmaengine: export symbol of of_dma_request_slave_channel()
Current DMAEngine implementation of DT bindings can't support
DT subnode. This patch export symbols of of_dma_request_slave_channel()
for subnode DMA DT bingings.

ex)

rcar_sound: rcar_sound@ec500000 {
        ...
        rcar_sound,dvc {
                dvc0: dvc@0 {
                        dmas = <&audma0 0xbc>;
                        dma-names = "tx";
                };
                dvc1: dvc@1 {
                        dmas = <&audma0 0xbe>;
                        dma-names = "tx";
                };
        };
        ...
};

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-07 15:03:13 +00:00
Wolfram Sang c914570f28 dmaengine: of: bail out early if "dmas" property is not present
And don't print an error: not configured is not an error.

Reported-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-01-25 22:44:23 -08:00
Alexander Popov 16369efb1f dmaengine: of: add common xlate function for matching by channel id
This patch adds a new common OF dma xlate callback function which will match a
channel by it's id. The binding expects one integer argument which it will use to
lookup the channel by the id.

Unlike of_dma_simple_xlate this function is able to handle a system with
multiple DMA controllers. When registering the of dma provider with
of_dma_controller_register a pointer to the dma_device struct which is
associated with the dt node needs to passed as the data parameter.
New function will use this pointer to match only channels which belong to the
specified DMA controller.

Signed-off-by: Alexander Popov <a13xp0p0v88@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-26 00:21:41 +05:30
Stephen Warren 0ad7c00057 dma: add channel request API that supports deferred probe
dma_request_slave_channel() simply returns NULL whenever DMA channel
lookup fails. Lookup could fail for two distinct reasons:

a) No DMA specification exists for the channel name.
   This includes situations where no DMA specifications exist at all, or
   other general lookup problems.

b) A DMA specification does exist, yet the driver for that channel is not
   yet registered.

Case (b) should trigger deferred probe in client drivers. However, since
they have no way to differentiate the two situations, it cannot.

Implement new function dma_request_slave_channel_reason(), which performs
identically to dma_request_slave_channel(), except that it returns an
error-pointer rather than NULL, which allows callers to detect when
deferred probe should occur.

Eventually, all drivers should be converted to this new API, the old API
removed, and the new API renamed to the more desirable name. This patch
doesn't convert the existing API and all drivers in one go, since some
drivers call dma_request_slave_channel() then dma_request_channel() if
that fails. That would require either modifying dma_request_channel() in
the same way, or adding extra error-handling code to all affected
drivers, and there are close to 100 drivers using the other API, rather
than just the 15-20 or so that use dma_request_slave_channel(), which
might be tenable in a single patch.

acpi_dma_request_slave_chan_by_name() doesn't currently implement
deferred probe. It should, but this will be addressed later.

Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-12-10 17:46:48 +05:30
Lothar Waßmann 303fd71d3f dma: of: make error message more meaningful by adding the node name
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-08-19 14:45:05 +05:30
Lars-Peter Clausen 8552bb4f16 dma: of: Remove check on always true condition
Both of_dma_nbcells field of the of_dma_controller and the args_count field of
the dma_spec are initialized by parsing the #dma-cells attribute of their device
tree node. So if the device tree nodes of a DMA controller and the dma_spec
match this means that of_dma_nbcells and args_count will also match. So the
second test in the of_dma_find_controller loop is redundant because given the
first test yields true the second test will also yield true. So we can safely
remove the test whether of_dma_nbcells matches args_count. Since this was the
last user of the of_dma_nbcells field we can remove it altogether.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-06-12 07:49:19 +05:30
Lars-Peter Clausen ff0e0f4f56 dma: of: Remove restriction that #dma-cells can't be 0
There is no sensible reason why #dma-cells shouldn't be allowed to be 0. It is
completely up to the DMA controller how many additional parameters, besides the
phandle, it needs to identify a channel. E.g. for DMA controller with only one
channel or for DMA controllers which don't have a restriction on which channel
can be used for which peripheral it completely legitimate to not require any
additional parameters.

Also fixes the following warning:
	drivers/dma/of-dma.c: In function 'of_dma_controller_register':
	drivers/dma/of-dma.c:67:7: warning: 'nbcells' may be used uninitialized in this function

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-06-12 07:49:19 +05:30
Lars-Peter Clausen de61608acf dma:of: Use a mutex to protect the of_dma_list
Currently the OF DMA code uses a spin lock to protect the of_dma_list from
concurrent access and a per controller reference count to protect the controller
from being freed while a request operation is in progress. If
of_dma_controller_free() is called for a controller who's reference count is not
zero it will return -EBUSY and not remove the controller. This is fine up until
here, but leaves the question what the caller of of_dma_controller_free() is
supposed to do if the controller couldn't be freed.  The only viable solution
for the caller is to spin on of_dma_controller_free() until it returns success.
E.g.

	do {
		ret = of_dma_controller_free(dev->of_node)
	} while (ret != -EBUSY);

This is rather ugly and unnecessary and none of the current users of
of_dma_controller_free() check it's return value anyway. Instead protect the
list by a mutex. The mutex will be held as long as a request operation is in
progress. So if of_dma_controller_free() is called while a request operation is
in progress it will be put to sleep and only wake up once the request operation
has finished.

This means that it is no longer possible to register or unregister OF DMA
controllers from a context where it's not possible to sleep. But I doubt that
we'll ever need this.

Also rename of_dma_get_controller back to of_dma_find_controller.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-05-02 21:50:38 +05:30
Lars-Peter Clausen f22eb14022 dma: of: Fix of_node reference leak
of_dma_request_slave_channel() currently does not drop the reference to the
dma_spec of_node if no DMA controller matching the of_node could be found. This
patch fixes it by always calling of_node_put().

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-05-02 21:50:38 +05:30
Lars-Peter Clausen af31826d9b dma: of: Remove unnecessary list_empty check
list_for_each_entry is able to handle empty lists just fine, there is no need
to make sure that the list is non empty.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-04-15 09:52:04 +05:30
Viresh Kumar 9a188eb126 DMA: OF: Check properties value before running be32_to_cpup() on it
In of_dma_controller_register() routine we are calling of_get_property() as an
parameter to be32_to_cpup(). In case the property doesn't exist we will get a
crash.

This patch changes this code to check if we got a valid property first and then
runs be32_to_cpup() on it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-04-15 09:52:03 +05:30
Markus Pargmann bef29ec508 DMA: of: Constant names
No DMA of-function alters the name, so this patch changes the name arguments
to be constant. Most drivers will probably request DMA channels using a
constant name.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-04-15 09:52:03 +05:30
Andy Shevchenko 88b386c0a7 dma: of-dma: protect list write operation by spin_lock
It's possible to have an inconsistency in the list due to unprotected operation
on it. The patch adds a proper locking on the list operation.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-02-14 20:00:53 +05:30
Cong Ding e68b1130df dma: of-dma.c: fix memory leakage
The memory allocated to ofdma might be a leakage when error occurs.

Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-02-14 19:11:46 +05:30
Vinod Koul 5fa422c922 dmaengine: move drivers/of/dma.c -> drivers/dma/of-dma.c
as requested by Rob

Suggested-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-02-13 08:09:37 -08:00