Messages in this thread Patch in this message | | | From | Stephen Warren <> | Subject | [PATCH V2] dma: add common of_dma_slave_xlate() | Date | Mon, 25 Nov 2013 18:25:04 -0700 |
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From: Stephen Warren <swarren@nvidia.com>
mmp_pdma.c implements a custom of_xlate() function that is 95% identical to what Tegra will need. Create a function to implement the common part, so everyone doesn't just cut/paste the implementation.
Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: dmaengine@vger.kernel.org Signed-off-by: Stephen Warren <swarren@nvidia.com> --- v2: Squashed the conversion of mmp_pdma.c into the patch that added the common implementation, so it's easier to see the whole conversion in one go.
This patch is a dependency for a series that reworks many of the Tegra drivers.
As such, it needs to go into a topic branch on its own, based directly on 3.13-rc1. If the DMA maintainers ack the patches I'm happy to create this topic branch myself and send a pull request to the DMA tree. Or the patches can be applied to a topic branch by the DMA maintainers and I will merge their topic branch into the Tegra rework branch that I mentioned.
Note that this patch is independant from the "dma: add channel request API that supports deferred probe" which I just sent, so it could (should?) be a different topic branch. --- drivers/dma/mmp_pdma.c | 39 ++++++++++----------------------------- drivers/dma/of-dma.c | 43 +++++++++++++++++++++++++++++++++++++++++++ include/linux/of_dma.h | 14 ++++++++++++++ 3 files changed, 67 insertions(+), 29 deletions(-)
diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index dcb1e05149a7..9705cedf623d 100644 --- a/drivers/dma/mmp_pdma.c +++ b/drivers/dma/mmp_pdma.c @@ -128,6 +128,7 @@ struct mmp_pdma_device { void __iomem *base; struct device *dev; struct dma_device device; + struct of_dma_slave_xlate_info xlate_info; struct mmp_pdma_phy *phy; spinlock_t phy_lock; /* protect alloc/free phy channels */ }; @@ -889,37 +890,14 @@ static struct of_device_id mmp_pdma_dt_ids[] = { }; MODULE_DEVICE_TABLE(of, mmp_pdma_dt_ids); -static struct dma_chan *mmp_pdma_dma_xlate(struct of_phandle_args *dma_spec, - struct of_dma *ofdma) +static int mmp_pdma_of_xlate_post_alloc(struct dma_chan *chan, + struct of_phandle_args *dma_spec) { - struct mmp_pdma_device *d = ofdma->of_dma_data; - struct dma_chan *chan, *candidate; - -retry: - candidate = NULL; - - /* walk the list of channels registered with the current instance and - * find one that is currently unused */ - list_for_each_entry(chan, &d->device.channels, device_node) - if (chan->client_count == 0) { - candidate = chan; - break; - } - - if (!candidate) - return NULL; + struct mmp_pdma_chan *c = to_mmp_pdma_chan(chan); - /* dma_get_slave_channel will return NULL if we lost a race between - * the lookup and the reservation */ - chan = dma_get_slave_channel(candidate); + c->drcmr = dma_spec->args[0]; - if (chan) { - struct mmp_pdma_chan *c = to_mmp_pdma_chan(chan); - c->drcmr = dma_spec->args[0]; - return chan; - } - - goto retry; + return 0; } static int mmp_pdma_probe(struct platform_device *op) @@ -1009,8 +987,11 @@ static int mmp_pdma_probe(struct platform_device *op) if (op->dev.of_node) { /* Device-tree DMA controller registration */ + pdev->xlate_info.device = &pdev->device; + pdev->xlate_info.post_alloc = mmp_pdma_of_xlate_post_alloc; ret = of_dma_controller_register(op->dev.of_node, - mmp_pdma_dma_xlate, pdev); + of_dma_slave_xlate, + &pdev->xlate_info); if (ret < 0) { dev_err(&op->dev, "of_dma_controller_register failed\n"); return ret; diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c index f68e25c9af3a..d9786a9c8797 100644 --- a/drivers/dma/of-dma.c +++ b/drivers/dma/of-dma.c @@ -218,3 +218,46 @@ struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec, &dma_spec->args[0]); } EXPORT_SYMBOL_GPL(of_dma_simple_xlate); + +struct dma_chan *of_dma_slave_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct of_dma_slave_xlate_info *info = ofdma->of_dma_data; + struct dma_chan *candidate, *chan; + int ret; + +retry: + candidate = NULL; + + /* + * walk the list of channels registered with the current instance and + * find one that is currently unused + */ + list_for_each_entry(chan, &info->device->channels, device_node) + if (chan->client_count == 0) { + candidate = chan; + break; + } + + if (!candidate) + return NULL; + + /* + * dma_get_slave_channel will return NULL if we lost a race between + * the lookup and the reservation + */ + chan = dma_get_slave_channel(candidate); + if (!chan) + goto retry; + + if (info->post_alloc) { + ret = info->post_alloc(chan, dma_spec); + if (ret) { + dma_release_channel(chan); + return NULL; + } + } + + return chan; +} +EXPORT_SYMBOL_GPL(of_dma_slave_xlate); diff --git a/include/linux/of_dma.h b/include/linux/of_dma.h index ae36298ba076..fb4187adc68b 100644 --- a/include/linux/of_dma.h +++ b/include/linux/of_dma.h @@ -31,6 +31,12 @@ struct of_dma_filter_info { dma_filter_fn filter_fn; }; +struct of_dma_slave_xlate_info { + struct dma_device *device; + int (*post_alloc)(struct dma_chan *chan, + struct of_phandle_args *dma_spec); +}; + #ifdef CONFIG_OF extern int of_dma_controller_register(struct device_node *np, struct dma_chan *(*of_dma_xlate) @@ -41,6 +47,8 @@ extern struct dma_chan *of_dma_request_slave_channel(struct device_node *np, const char *name); extern struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma); +extern struct dma_chan *of_dma_slave_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma); #else static inline int of_dma_controller_register(struct device_node *np, struct dma_chan *(*of_dma_xlate) @@ -66,6 +74,12 @@ static inline struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_s return NULL; } +static inline struct dma_chan *of_dma_slave_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + return NULL; +} + #endif #endif /* __LINUX_OF_DMA_H */ -- 1.8.1.5
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