On 09/01/2011 04:04 AM, Thomas Abraham wrote: > For PL330 dma controllers instantiated from device tree, the channel > lookup is based on phandle of the dma controller and dma request id > specified by the client node. During probe, the private data of each > channel of the controller is set to point to the device node of the > dma controller. The 'chan_id' of the each channel is used as the > dma request id. > > Client driver requesting dma channels specify the phandle of the > dma controller and the request id. The pl330 filter function > converts the phandle to the device node pointer and matches that > with channel's private data. If a match is found, the request id > from the client node and the 'chan_id' of the channel is matched. > A channel is found if both the values match. > > Cc: Jassi Brar <[email protected]> > Cc: Boojin Kim <[email protected]> > Signed-off-by: Thomas Abraham <[email protected]>
Looks good. Reviewed-by: Rob Herring <[email protected]> > --- > .../devicetree/bindings/dma/arm-pl330.txt | 29 ++++++++++++++++ > drivers/dma/pl330.c | 35 > +++++++++++++++++--- > 2 files changed, 59 insertions(+), 5 deletions(-) > create mode 100644 Documentation/devicetree/bindings/dma/arm-pl330.txt > > diff --git a/Documentation/devicetree/bindings/dma/arm-pl330.txt > b/Documentation/devicetree/bindings/dma/arm-pl330.txt > new file mode 100644 > index 0000000..69e6c02 > --- /dev/null > +++ b/Documentation/devicetree/bindings/dma/arm-pl330.txt > @@ -0,0 +1,29 @@ > +* ARM PrimeCell PL330 DMA Controller > + > +The ARM PrimeCell PL330 DMA controller can move blocks of memory contents > +between memory and peripherals or memory to memory. > + > +Required properties: > + - compatible: should include both "arm,pl330" and "arm,primecell". > + - reg: physical base address of the controller and length of memory mapped > + region. > + - interrupts: interrupt number to the cpu. > + > +Example: (from Samsung's Exynos4 processor dtsi file) > + > + pdma0: pdma@12680000 { > + compatible = "arm,pl330", "arm,primecell"; > + reg = <0x12680000 0x1000>; > + interrupts = <99>; > + }; > + > +Client drivers (device nodes requiring dma transfers from dev-to-mem or > +mem-to-dev) should specify the DMA channel numbers using a two-value pair > +as shown below. > + > + [property name] = <[phandle of the dma controller] [dma request id]>; > + > + where 'dma request id' is the dma request number which is connected > + to the client controller. > + > + Example: tx-dma-channel = <&pdma0 12>; > diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c > index 9732995..0c55de4 100644 > --- a/drivers/dma/pl330.c > +++ b/drivers/dma/pl330.c > @@ -19,6 +19,7 @@ > #include <linux/amba/pl330.h> > #include <linux/pm_runtime.h> > #include <linux/scatterlist.h> > +#include <linux/of.h> > > #define NR_DEFAULT_DESC 16 > > @@ -277,6 +278,20 @@ bool pl330_filter(struct dma_chan *chan, void *param) > if (chan->device->dev->driver != &pl330_driver.drv) > return false; > > +#ifdef CONFIG_OF > + if (chan->device->dev->of_node) { > + const __be32 *prop_value; > + phandle phandle; > + struct device_node *node; > + > + prop_value = ((struct property *)param)->value; > + phandle = be32_to_cpup(prop_value++); > + node = of_find_node_by_phandle(phandle); > + return ((chan->private == node) && > + (chan->chan_id == be32_to_cpup(prop_value))); > + } > +#endif > + > peri_id = chan->private; > return *peri_id == (unsigned)param; > } > @@ -857,12 +872,17 @@ pl330_probe(struct amba_device *adev, const struct > amba_id *id) > INIT_LIST_HEAD(&pd->channels); > > /* Initialize channel parameters */ > - num_chan = max(pdat ? pdat->nr_valid_peri : 0, (u8)pi->pcfg.num_chan); > + num_chan = max(pdat ? pdat->nr_valid_peri : (u8)pi->pcfg.num_peri, > + (u8)pi->pcfg.num_chan); > pdmac->peripherals = kzalloc(num_chan * sizeof(*pch), GFP_KERNEL); > > for (i = 0; i < num_chan; i++) { > pch = &pdmac->peripherals[i]; > - pch->chan.private = pdat ? &pdat->peri_id[i] : NULL; > + if (!adev->dev.of_node) > + pch->chan.private = pdat ? &pdat->peri_id[i] : NULL; > + else > + pch->chan.private = adev->dev.of_node; > + > INIT_LIST_HEAD(&pch->work_list); > spin_lock_init(&pch->lock); > pch->pl330_chid = NULL; > @@ -876,11 +896,16 @@ pl330_probe(struct amba_device *adev, const struct > amba_id *id) > } > > pd->dev = &adev->dev; > - if (pdat) > + if (pdat) { > pd->cap_mask = pdat->cap_mask; > - else > + } else { > dma_cap_set(DMA_MEMCPY, pd->cap_mask); > - > + if (pi->pcfg.num_peri) { > + dma_cap_set(DMA_SLAVE, pd->cap_mask); > + dma_cap_set(DMA_CYCLIC, pd->cap_mask); > + } > + } > + > pd->device_alloc_chan_resources = pl330_alloc_chan_resources; > pd->device_free_chan_resources = pl330_free_chan_resources; > pd->device_prep_dma_memcpy = pl330_prep_dma_memcpy; _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
