From 0f73f3e85757091f40019b71077b41a717182b29 Mon Sep 17 00:00:00 2001 From: Peter Ujfalusi Date: Fri, 30 Oct 2015 10:00:37 +0200 Subject: [PATCH] dmaengine: ti-dma-crossbar: dra7: Support for reserving DMA event ranges In eDMA the events are directly mapped to a DMA channel (for example DMA event 14 can only be handled by DMA channel 14). If the memcpy is enabled on the eDMA, there is a possibility that the crossbar driver would assign DMA event number already allocated in eDMA for memcpy. Furthermore the eDMA can be shared with DSP in which case the crossbar driver should also avoid mapping xbar events to DSP used event numbers (or channels). Signed-off-by: Peter Ujfalusi Signed-off-by: Vinod Koul --- .../bindings/dma/ti-dma-crossbar.txt | 6 +++ drivers/dma/ti-dma-crossbar.c | 47 +++++++++++++++++-- 2 files changed, 49 insertions(+), 4 deletions(-) diff --git a/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt index b152a75dceae..aead5869a28d 100644 --- a/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt +++ b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt @@ -14,6 +14,10 @@ The DMA controller node need to have the following poroperties: Optional properties: - ti,dma-safe-map: Safe routing value for unused request lines +- ti,reserved-dma-request-ranges: DMA request ranges which should not be used + when mapping xbar input to DMA request, they are either + allocated to be used by for example the DSP or they are used as + memcpy channels in eDMA. Notes: When requesting channel via ti,dra7-dma-crossbar, the DMA clinet must request @@ -46,6 +50,8 @@ sdma_xbar: dma-router@4a002b78 { #dma-cells = <1>; dma-requests = <205>; ti,dma-safe-map = <0>; + /* Protect the sDMA request ranges: 10-14 and 100-126 */ + ti,reserved-dma-request-ranges = <10 5>, <100 27>; dma-masters = <&sdma>; }; diff --git a/drivers/dma/ti-dma-crossbar.c b/drivers/dma/ti-dma-crossbar.c index 7b1e3ea874bf..e107779b1a2e 100644 --- a/drivers/dma/ti-dma-crossbar.c +++ b/drivers/dma/ti-dma-crossbar.c @@ -296,14 +296,22 @@ static const struct of_device_id ti_dra7_master_match[] = { {}, }; +static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p) +{ + for (; len > 0; len--) + clear_bit(offset + (len - 1), p); +} + static int ti_dra7_xbar_probe(struct platform_device *pdev) { struct device_node *node = pdev->dev.of_node; const struct of_device_id *match; struct device_node *dma_node; struct ti_dra7_xbar_data *xbar; + struct property *prop; struct resource *res; u32 safe_val; + size_t sz; void __iomem *iomem; int i, ret; @@ -351,6 +359,33 @@ static int ti_dra7_xbar_probe(struct platform_device *pdev) if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val)) xbar->safe_val = (u16)safe_val; + + prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz); + if (prop) { + const char pname[] = "ti,reserved-dma-request-ranges"; + u32 (*rsv_events)[2]; + size_t nelm = sz / sizeof(*rsv_events); + int i; + + if (!nelm) + return -EINVAL; + + rsv_events = kcalloc(nelm, sizeof(*rsv_events), GFP_KERNEL); + if (!rsv_events) + return -ENOMEM; + + ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events, + nelm * 2); + if (ret) + return ret; + + for (i = 0; i < nelm; i++) { + ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1], + xbar->dma_inuse); + } + kfree(rsv_events); + } + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); iomem = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(iomem)) @@ -366,15 +401,19 @@ static int ti_dra7_xbar_probe(struct platform_device *pdev) platform_set_drvdata(pdev, xbar); /* Reset the crossbar */ - for (i = 0; i < xbar->dma_requests; i++) - ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val); + for (i = 0; i < xbar->dma_requests; i++) { + if (!test_bit(i, xbar->dma_inuse)) + ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val); + } ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate, &xbar->dmarouter); if (ret) { /* Restore the defaults for the crossbar */ - for (i = 0; i < xbar->dma_requests; i++) - ti_dra7_xbar_write(xbar->iomem, i, i); + for (i = 0; i < xbar->dma_requests; i++) { + if (!test_bit(i, xbar->dma_inuse)) + ti_dra7_xbar_write(xbar->iomem, i, i); + } } return ret; -- 2.20.1