1 files changed, 43 insertions, 12 deletions

diff --git a/arch/arm/mach-davinci/dma.c b/arch/arm/mach-davinci/dma.c
index 89a3dccde19f..15dd886df04c 100644
--- a/arch/arm/mach-davinci/dma.c
+++ b/arch/arm/mach-davinci/dma.c
@@ -226,11 +226,11 @@ struct edma {
          */
         DECLARE_BITMAP(edma_inuse, EDMA_MAX_PARAMENTRY);
 
-        /* The edma_noevent bit for each channel is clear unless
-         * it doesn't trigger DMA events on this platform.  It uses a
-         * bit of SOC-specific initialization code.
+        /* The edma_unused bit for each channel is clear unless
+         * it is not being used on this platform. It uses a bit
+         * of SOC-specific initialization code.
          */
-        DECLARE_BITMAP(edma_noevent, EDMA_MAX_DMACH);
+        DECLARE_BITMAP(edma_unused, EDMA_MAX_DMACH);
 
         unsigned        irq_res_start;
         unsigned        irq_res_end;
@@ -556,8 +556,27 @@ static int reserve_contiguous_slots(int ctlr, unsigned int id,
         return EDMA_CTLR_CHAN(ctlr, i - num_slots + 1);
 }
 
+static int prepare_unused_channel_list(struct device *dev, void *data)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        int i, ctlr;
+
+        for (i = 0; i < pdev->num_resources; i++) {
+                if ((pdev->resource[i].flags & IORESOURCE_DMA) &&
+                                (int)pdev->resource[i].start >= 0) {
+                        ctlr = EDMA_CTLR(pdev->resource[i].start);
+                        clear_bit(EDMA_CHAN_SLOT(pdev->resource[i].start),
+                                        edma_info[ctlr]->edma_unused);
+                }
+        }
+
+        return 0;
+}
+
 /*-----------------------------------------------------------------------*/
 
+static bool unused_chan_list_done;
+
 /* Resource alloc/free:  dma channels, parameter RAM slots */
 
 /**
@@ -596,6 +615,21 @@ int edma_alloc_channel(int channel,
                 enum dma_event_q eventq_no)
 {
         unsigned i, done = 0, ctlr = 0;
+        int ret = 0;
+
+        if (!unused_chan_list_done) {
+                /*
+                 * Scan all the platform devices to find out the EDMA channels
+                 * used and clear them in the unused list, making the rest
+                 * available for ARM usage.
+                 */
+                ret = bus_for_each_dev(&platform_bus_type, NULL, NULL,
+                                prepare_unused_channel_list);
+                if (ret < 0)
+                        return ret;
+
+                unused_chan_list_done = true;
+        }
 
         if (channel >= 0) {
                 ctlr = EDMA_CTLR(channel);
@@ -607,7 +641,7 @@ int edma_alloc_channel(int channel,
                         channel = 0;
                         for (;;) {
                                 channel = find_next_bit(edma_info[i]->
-                                                edma_noevent,
+                                                edma_unused,
                                                 edma_info[i]->num_channels,
                                                 channel);
                                 if (channel == edma_info[i]->num_channels)
@@ -1222,7 +1256,7 @@ int edma_start(unsigned channel)
                 unsigned int mask = (1 << (channel & 0x1f));
 
                 /* EDMA channels without event association */
-                if (test_bit(channel, edma_info[ctlr]->edma_noevent)) {
+                if (test_bit(channel, edma_info[ctlr]->edma_unused)) {
                         pr_debug("EDMA: ESR%d %08x\n", j,
                                 edma_shadow0_read_array(ctlr, SH_ESR, j));
                         edma_shadow0_write_array(ctlr, SH_ESR, j, mask);
@@ -1347,7 +1381,6 @@ static int __init edma_probe(struct platform_device *pdev)
         const s8                (*queue_tc_mapping)[2];
         int                     i, j, found = 0;
         int                     status = -1;
-        const s8                *noevent;
         int                     irq[EDMA_MAX_CC] = {0, 0};
         int                     err_irq[EDMA_MAX_CC] = {0, 0};
         struct resource         *r[EDMA_MAX_CC] = {NULL};
@@ -1410,11 +1443,9 @@ static int __init edma_probe(struct platform_device *pdev)
                         memcpy_toio(edmacc_regs_base[j] + PARM_OFFSET(i),
                                         &dummy_paramset, PARM_SIZE);
 
-                noevent = info[j].noevent;
-                if (noevent) {
-                        while (*noevent != -1)
-                                set_bit(*noevent++, edma_info[j]->edma_noevent);
-                }
+                /* Mark all channels as unused */
+                memset(edma_info[j]->edma_unused, 0xff,
+                        sizeof(edma_info[j]->edma_unused));
 
                 sprintf(irq_name, "edma%d", j);
                 irq[j] = platform_get_irq_byname(pdev, irq_name);