Each dma-request channel can be connected to the dma-controller either
directly or through a crossbar router. In such cases request lines
should be routed to the dma-controller. Adding a xlate function
which would retrieve and store the router data associated with a particular
channel in the dma-channel specific structure. This is used to map/unmap
the dma request lines.

Signed-off-by: Sricharan R <r.sricha...@ti.com>
---
 drivers/dma/omap-dma.c |   47 ++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index a0d6639..38407f9 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -44,6 +44,8 @@ struct omap_chan {
        uint32_t ccr;
 
        struct dma_slave_config cfg;
+       struct dma_xbar_device *router;
+
        unsigned dma_sig;
        bool cyclic;
        bool paused;
@@ -75,6 +77,11 @@ struct omap_desc {
        struct omap_sg sg[0];
 };
 
+struct omap_dma_filter_args {
+       void *router_data;
+       unsigned chan;
+};
+
 enum {
        CCR_FS                  = BIT(5),
        CCR_READ_PRIORITY       = BIT(6),
@@ -586,6 +593,7 @@ static void omap_dma_free_chan_resources(struct dma_chan 
*chan)
        c->channel_base = NULL;
        od->lch_map[c->dma_ch] = NULL;
        vchan_free_chan_resources(&c->vc);
+
        omap_free_dma(c->dma_ch);
 
        dev_dbg(od->ddev.dev, "freeing channel for %u\n", c->dma_sig);
@@ -1088,6 +1096,34 @@ static void omap_dma_free(struct omap_dmadev *od)
        }
 }
 
+static struct dma_chan *of_omap_dma_xlate(struct of_phandle_args *dma_spec,
+                                                struct of_dma *ofdma)
+{
+       int count = dma_spec->args_count;
+       struct of_dma_filter_info *info = ofdma->of_dma_data;
+       struct omap_dma_filter_args args;
+       struct dma_xbar_device *c = NULL;
+
+       if (!info || !info->filter_fn)
+               return NULL;
+
+       if ((count != 1) && (count != 2))
+               return NULL;
+
+       args.chan = dma_spec->args[0];
+       args.router_data = NULL;
+
+       if (count == 2) {
+               c = of_dma_get_router_data(dma_spec->args[1]);
+
+               if (c && c->ops && c->ops->map && c->ops->unmap)
+                       args.router_data = c;
+       }
+
+       return dma_request_channel(info->dma_cap, info->filter_fn,
+                       &args);
+}
+
 static int omap_dma_probe(struct platform_device *pdev)
 {
        struct omap_dmadev *od;
@@ -1167,7 +1203,7 @@ static int omap_dma_probe(struct platform_device *pdev)
 
                /* Device-tree DMA controller registration */
                rc = of_dma_controller_register(pdev->dev.of_node,
-                               of_dma_simple_xlate, &omap_dma_info);
+                               of_omap_dma_xlate, &omap_dma_info);
                if (rc) {
                        pr_warn("OMAP-DMA: failed to register DMA 
controller\n");
                        dma_async_device_unregister(&od->ddev);
@@ -1221,11 +1257,16 @@ static struct platform_driver omap_dma_driver = {
 
 bool omap_dma_filter_fn(struct dma_chan *chan, void *param)
 {
+       struct omap_dma_filter_args *args = param;
+
        if (chan->device->dev->driver == &omap_dma_driver.driver) {
                struct omap_chan *c = to_omap_dma_chan(chan);
-               unsigned req = *(unsigned *)param;
+               unsigned req = args->chan;
 
-               return req == c->dma_sig;
+               if (req == c->dma_sig) {
+                       c->router = args->router_data;
+                       return true;
+               }
        }
        return false;
 }
-- 
1.7.9.5

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