1 files changed, 64 insertions, 5 deletions

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index fe33ddd8eb0f..82a7ac7c048b 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -194,14 +194,73 @@ static void omap_dma_free_chan_resources(struct dma_chan *chan)
         dev_info(c->vc.chan.device->dev, "freeing channel for %u\n", c->dma_sig);
 }
 
+static size_t omap_dma_sg_size(struct omap_sg *sg)
+{
+        return sg->en * sg->fn;
+}
+
+static size_t omap_dma_desc_size(struct omap_desc *d)
+{
+        unsigned i;
+        size_t size;
+
+        for (size = i = 0; i < d->sglen; i++)
+                size += omap_dma_sg_size(&d->sg[i]);
+
+        return size * es_bytes[d->es];
+}
+
+static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr)
+{
+        unsigned i;
+        size_t size, es_size = es_bytes[d->es];
+
+        for (size = i = 0; i < d->sglen; i++) {
+                size_t this_size = omap_dma_sg_size(&d->sg[i]) * es_size;
+
+                if (size)
+                        size += this_size;
+                else if (addr >= d->sg[i].addr &&
+                         addr < d->sg[i].addr + this_size)
+                        size += d->sg[i].addr + this_size - addr;
+        }
+        return size;
+}
+
 static enum dma_status omap_dma_tx_status(struct dma_chan *chan,
         dma_cookie_t cookie, struct dma_tx_state *txstate)
 {
-        /*
-         * FIXME: do we need to return pending bytes?
-         * We have no users of that info at the moment...
-         */
-        return dma_cookie_status(chan, cookie, txstate);
+        struct omap_chan *c = to_omap_dma_chan(chan);
+        struct virt_dma_desc *vd;
+        enum dma_status ret;
+        unsigned long flags;
+
+        ret = dma_cookie_status(chan, cookie, txstate);
+        if (ret == DMA_SUCCESS || !txstate)
+                return ret;
+
+        spin_lock_irqsave(&c->vc.lock, flags);
+        vd = vchan_find_desc(&c->vc, cookie);
+        if (vd) {
+                txstate->residue = omap_dma_desc_size(to_omap_dma_desc(&vd->tx));
+        } else if (c->desc && c->desc->vd.tx.cookie == cookie) {
+                struct omap_desc *d = c->desc;
+                dma_addr_t pos;
+
+                if (d->dir == DMA_MEM_TO_DEV)
+                        pos = omap_get_dma_src_pos(c->dma_ch);
+                else if (d->dir == DMA_DEV_TO_MEM)
+                        pos = omap_get_dma_dst_pos(c->dma_ch);
+                else
+                        pos = 0;
+
+                txstate->residue = omap_dma_desc_size_pos(d, pos);
+        } else {
+                txstate->residue = 0;
+        }
+        spin_unlock_irqrestore(&c->vc.lock, flags);
+
+        return ret;
 }
 
 static void omap_dma_issue_pending(struct dma_chan *chan)