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* dmaengine: of_dma: approximate an average distributionNiklas Söderlund2016-05-141-2/+10
| | | | | | | | | | | | | | | | | | | | | 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>
* dmaengine: of_dma: Support for DMA routersPeter Ujfalusi2015-05-091-0/+89
| | | | | | | | | | | | | | | | | | 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>
* dmaengine: export symbol of of_dma_request_slave_channel()Kuninori Morimoto2015-03-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dmaengine: of: bail out early if "dmas" property is not presentWolfram Sang2015-01-251-0/+4
| | | | | | | | | | | 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>
* dmaengine: of: add common xlate function for matching by channel idAlexander Popov2014-07-261-0/+35
| | | | | | | | | | | | | | | | 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>
* dma: add channel request API that supports deferred probeStephen Warren2013-12-101-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dma: of: make error message more meaningful by adding the node nameLothar Waßmann2013-08-191-1/+2
| | | | | Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
* dma: of: Remove check on always true conditionLars-Peter Clausen2013-06-121-13/+1
| | | | | | | | | | | | | | | 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>
* dma: of: Remove restriction that #dma-cells can't be 0Lars-Peter Clausen2013-06-121-7/+4
| | | | | | | | | | | | | | | | | 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>
* dma:of: Use a mutex to protect the of_dma_listLars-Peter Clausen2013-05-021-56/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dma: of: Fix of_node reference leakLars-Peter Clausen2013-05-021-5/+6
| | | | | | | | | | | 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>
* dma: of: Remove unnecessary list_empty checkLars-Peter Clausen2013-04-151-5/+0
| | | | | | | | 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>
* DMA: OF: Check properties value before running be32_to_cpup() on itViresh Kumar2013-04-151-2/+6
| | | | | | | | | | | | 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>
* DMA: of: Constant namesMarkus Pargmann2013-04-151-3/+3
| | | | | | | | | 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>
* dma: of-dma: protect list write operation by spin_lockAndy Shevchenko2013-02-141-0/+2
| | | | | | | | | | 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>
* dma: of-dma.c: fix memory leakageCong Ding2013-02-141-0/+1
| | | | | | | 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>
* dmaengine: move drivers/of/dma.c -> drivers/dma/of-dma.cVinod Koul2013-02-131-0/+264
as requested by Rob Suggested-by: Rob Herring <rob.herring@calxeda.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
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