10 files changed, 430 insertions, 6 deletions

diff --git a/Documentation/devicetree/bindings/dma/dma.txt b/Documentation/devicetree/bindings/dma/dma.txt
index 82104271e754..6312fb00ce8d 100644
--- a/Documentation/devicetree/bindings/dma/dma.txt
+++ b/Documentation/devicetree/bindings/dma/dma.txt
@@ -31,6 +31,34 @@ Example:
                 dma-requests = <127>;
         };
 
+* DMA router
+
+DMA routers are transparent IP blocks used to route DMA request lines from
+devices to the DMA controller. Some SoCs (like TI DRA7x) have more peripherals
+integrated with DMA requests than what the DMA controller can handle directly.
+
+Required property:
+- dma-masters:          phandle of the DMA controller or list of phandles for
+                        the DMA controllers the router can direct the signal to.
+- #dma-cells:           Must be at least 1. Used to provide DMA router specific
+                        information. See DMA client binding below for more
+                        details.
+
+Optional properties:
+- dma-requests:         Number of incoming request lines the router can handle.
+- In the node pointed by the dma-masters:
+        - dma-requests: The router driver might need to look for this in order
+                        to configure the routing.
+
+Example:
+        sdma_xbar: dma-router@4a002b78 {
+                compatible = "ti,dra7-dma-crossbar";
+                reg = <0x4a002b78 0xfc>;
+                #dma-cells = <1>;
+                dma-requests = <205>;
+                ti,dma-safe-map = <0>;
+                dma-masters = <&sdma>;
+        };
 
 * DMA client
 
diff --git a/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
new file mode 100644
index 000000000000..63a48928f3a8
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
@@ -0,0 +1,52 @@
+Texas Instruments DMA Crossbar (DMA request router)
+
+Required properties:
+- compatible:   "ti,dra7-dma-crossbar" for DRA7xx DMA crossbar
+- reg:          Memory map for accessing module
+- #dma-cells:   Should be set to <1>.
+                Clients should use the crossbar request number (input)
+- dma-requests: Number of DMA requests the crossbar can receive
+- dma-masters:  phandle pointing to the DMA controller
+
+The DMA controller node need to have the following poroperties:
+- dma-requests: Number of DMA requests the controller can handle
+
+Optional properties:
+- ti,dma-safe-map: Safe routing value for unused request lines
+
+Example:
+
+/* DMA controller */
+sdma: dma-controller@4a056000 {
+        compatible = "ti,omap4430-sdma";
+        reg = <0x4a056000 0x1000>;
+        interrupts =    <GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>,
+                        <GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>,
+                        <GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>,
+                        <GIC_SPI 10 IRQ_TYPE_LEVEL_HIGH>;
+        #dma-cells = <1>;
+        dma-channels = <32>;
+        dma-requests = <127>;
+};
+
+/* DMA crossbar */
+sdma_xbar: dma-router@4a002b78 {
+        compatible = "ti,dra7-dma-crossbar";
+        reg = <0x4a002b78 0xfc>;
+        #dma-cells = <1>;
+        dma-requests = <205>;
+        ti,dma-safe-map = <0>;
+        dma-masters = <&sdma>;
+};
+
+/* DMA client */
+uart1: serial@4806a000 {
+        compatible = "ti,omap4-uart";
+        reg = <0x4806a000 0x100>;
+        interrupts-extended = <&gic GIC_SPI 67 IRQ_TYPE_LEVEL_HIGH>;
+        ti,hwmods = "uart1";
+        clock-frequency = <48000000>;
+        status = "disabled";
+        dmas = <&sdma_xbar 49>, <&sdma_xbar 50>;
+        dma-names = "tx", "rx";
+};
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index bda2cb06dc7a..0205ade0ba32 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -245,6 +245,9 @@ config TI_EDMA
           Enable support for the TI EDMA controller. This DMA
           engine is found on TI DaVinci and AM33xx parts.
 
+config TI_DMA_CROSSBAR
+        bool
+
 config ARCH_HAS_ASYNC_TX_FIND_CHANNEL
         bool
 
@@ -330,6 +333,7 @@ config DMA_OMAP
         depends on ARCH_OMAP
         select DMA_ENGINE
         select DMA_VIRTUAL_CHANNELS
+        select TI_DMA_CROSSBAR if SOC_DRA7XX
 
 config DMA_BCM2835
         tristate "BCM2835 DMA engine support"
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 69f77d5ba53b..535919559f12 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_EP93XX_DMA) += ep93xx_dma.o
 obj-$(CONFIG_DMA_SA11X0) += sa11x0-dma.o
 obj-$(CONFIG_MMP_TDMA) += mmp_tdma.o
 obj-$(CONFIG_DMA_OMAP) += omap-dma.o
+obj-$(CONFIG_TI_DMA_CROSSBAR) += ti-dma-crossbar.o
 obj-$(CONFIG_DMA_BCM2835) += bcm2835-dma.o
 obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
 obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index c0793818bb99..052a2bd1a5cf 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -267,6 +267,13 @@ static void dma_chan_put(struct dma_chan *chan)
         /* This channel is not in use anymore, free it */
         if (!chan->client_count && chan->device->device_free_chan_resources)
                 chan->device->device_free_chan_resources(chan);
+
+        /* If the channel is used via a DMA request router, free the mapping */
+        if (chan->router && chan->router->route_free) {
+                chan->router->route_free(chan->router->dev, chan->route_data);
+                chan->router = NULL;
+                chan->route_data = NULL;
+        }
 }
 
 enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
index cbd4a8aff120..1e1f2986eba8 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -45,6 +45,50 @@ static struct of_dma *of_dma_find_controller(struct of_phandle_args *dma_spec)
 }
 
 /**
+ * of_dma_router_xlate - translation function for router devices
+ * @dma_spec:   pointer to DMA specifier as found in the device tree
+ * @of_dma:     pointer to DMA controller data (router information)
+ *
+ * The function creates new dma_spec to be passed to the router driver's
+ * of_dma_route_allocate() function to prepare a dma_spec which will be used
+ * to request channel from the real DMA controller.
+ */
+static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec,
+                                            struct of_dma *ofdma)
+{
+        struct dma_chan         *chan;
+        struct of_dma           *ofdma_target;
+        struct of_phandle_args  dma_spec_target;
+        void                    *route_data;
+
+        /* translate the request for the real DMA controller */
+        memcpy(&dma_spec_target, dma_spec, sizeof(dma_spec_target));
+        route_data = ofdma->of_dma_route_allocate(&dma_spec_target, ofdma);
+        if (IS_ERR(route_data))
+                return NULL;
+
+        ofdma_target = of_dma_find_controller(&dma_spec_target);
+        if (!ofdma_target)
+                return NULL;
+
+        chan = ofdma_target->of_dma_xlate(&dma_spec_target, ofdma_target);
+        if (chan) {
+                chan->router = ofdma->dma_router;
+                chan->route_data = route_data;
+        } else {
+                ofdma->dma_router->route_free(ofdma->dma_router->dev,
+                                              route_data);
+        }
+
+        /*
+         * Need to put the node back since the ofdma->of_dma_route_allocate
+         * has taken i