Read the current DMA position from the hardware directly rather than via
arch/arm/plat-omap/dma.c.
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
---
drivers/dma/omap-dma.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 64 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 7aa5ff7ab935..323eae2c9d08 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -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;
--
1.8.3.1
--
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