dmaengine: omap-dma: move reading of dma position to omap-dma.c
authorRussell King <rmk+kernel@arm.linux.org.uk>
Sat, 2 Nov 2013 18:04:17 +0000 (18:04 +0000)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Thu, 3 Apr 2014 23:27:53 +0000 (00:27 +0100)
Read the current DMA position from the hardware directly rather than via
arch/arm/plat-omap/dma.c.

Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
drivers/dma/omap-dma.c

index 7aa5ff7ab935390090ccee4392e8d0ba428b5510..323eae2c9d08019d16e06f310938bd6a2ff602a7 100644 (file)
@@ -427,6 +427,68 @@ static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr)
        return size;
 }
 
+static dma_addr_t omap_dma_get_src_pos(struct omap_chan *c)
+{
+       struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
+       dma_addr_t addr;
+
+       if (__dma_omap15xx(od->plat->dma_attr))
+               addr = c->plat->dma_read(CPC, c->dma_ch);
+       else
+               addr = c->plat->dma_read(CSAC, c->dma_ch);
+
+       if (od->plat->errata & DMA_ERRATA_3_3 && addr == 0)
+               addr = c->plat->dma_read(CSAC, c->dma_ch);
+
+       if (!__dma_omap15xx(od->plat->dma_attr)) {
+               /*
+                * CDAC == 0 indicates that the DMA transfer on the channel has
+                * not been started (no data has been transferred so far).
+                * Return the programmed source start address in this case.
+                */
+               if (c->plat->dma_read(CDAC, c->dma_ch))
+                       addr = c->plat->dma_read(CSAC, c->dma_ch);
+               else
+                       addr = c->plat->dma_read(CSSA, c->dma_ch);
+       }
+
+       if (dma_omap1())
+               addr |= c->plat->dma_read(CSSA, c->dma_ch) & 0xffff0000;
+
+       return addr;
+}
+
+static dma_addr_t omap_dma_get_dst_pos(struct omap_chan *c)
+{
+       struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
+       dma_addr_t addr;
+
+       if (__dma_omap15xx(od->plat->dma_attr))
+               addr = c->plat->dma_read(CPC, c->dma_ch);
+       else
+               addr = c->plat->dma_read(CDAC, c->dma_ch);
+
+       /*
+        * omap 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is
+        * read before the DMA controller finished disabling the channel.
+        */
+       if (!__dma_omap15xx(od->plat->dma_attr) && addr == 0) {
+               addr = c->plat->dma_read(CDAC, c->dma_ch);
+               /*
+                * CDAC == 0 indicates that the DMA transfer on the channel has
+                * not been started (no data has been transferred so far).
+                * Return the programmed destination start address in this case.
+                */
+               if (addr == 0)
+                       addr = c->plat->dma_read(CDSA, c->dma_ch);
+       }
+
+       if (dma_omap1())
+               addr |= c->plat->dma_read(CDSA, c->dma_ch) & 0xffff0000;
+
+       return addr;
+}
+
 static enum dma_status omap_dma_tx_status(struct dma_chan *chan,
        dma_cookie_t cookie, struct dma_tx_state *txstate)
 {
@@ -448,9 +510,9 @@ static enum dma_status omap_dma_tx_status(struct dma_chan *chan,
                dma_addr_t pos;
 
                if (d->dir == DMA_MEM_TO_DEV)
-                       pos = omap_get_dma_src_pos(c->dma_ch);
+                       pos = omap_dma_get_src_pos(c);
                else if (d->dir == DMA_DEV_TO_MEM)
-                       pos = omap_get_dma_dst_pos(c->dma_ch);
+                       pos = omap_dma_get_dst_pos(c);
                else
                        pos = 0;