From 111d302c302d1c3020aecf57ed6ee9cb688f8c91 Mon Sep 17 00:00:00 2001 From: Thomas Abraham Date: Mon, 24 Oct 2011 11:43:31 +0200 Subject: [PATCH] DMA: PL330: Add device tree support 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. Acked-by: Jassi Brar Acked-by: Boojin Kim Signed-off-by: Thomas Abraham Reviewed-by: Rob Herring Acked-by: Grant Likely Acked-by: Vinod Koul Signed-off-by: Kukjin Kim --- .../devicetree/bindings/dma/arm-pl330.txt | 30 +++++++++++++++++ drivers/dma/pl330.c | 33 ++++++++++++++++--- 2 files changed, 59 insertions(+), 4 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 000000000000..a4cd273b2a67 --- /dev/null +++ b/Documentation/devicetree/bindings/dma/arm-pl330.txt @@ -0,0 +1,30 @@ +* 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: + + 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. The 'property name' is recommended to be + of the form -dma-channel. + + Example: tx-dma-channel = <&pdma0 12>; diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 992bf8222b87..7a4ebf1cb9f6 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -19,6 +19,7 @@ #include #include #include +#include #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; } @@ -855,12 +870,17 @@ 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; @@ -874,10 +894,15 @@ 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; -- 2.39.5