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;