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authorMagnus Damm <damm@opensource.se>2011-05-24 10:31:12 +0000
committerPaul Mundt <lethal@linux-sh.org>2011-05-25 11:35:23 +0900
commit26fc02ab5551349b2e593829a76cb44328ee7f61 (patch)
tree3ad395f8942e2e2ad869f508434e3738ad28bf45 /drivers/dma
parent66ad12931d523e833516659eafcc29af9a08fff3 (diff)
dmaengine: shdma: Make second memory window optional
This patch makes the shdma.c driver allow slave operation on DMA hardware mapped with a single I/O-memory window. The dmae_set_dmars() function is adjusted to use the first memory window in case of a missing DMARS window. At probe() time the code is updated to enable DMA_SLAVE only if slave information is passed with the platform data. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/shdma.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/dma/shdma.c b/drivers/dma/shdma.c
index dcc1b2139ff..3391b157d05 100644
--- a/drivers/dma/shdma.c
+++ b/drivers/dma/shdma.c
@@ -213,12 +213,17 @@ static int dmae_set_dmars(struct sh_dmae_chan *sh_chan, u16 val)
struct sh_dmae_device, common);
struct sh_dmae_pdata *pdata = shdev->pdata;
const struct sh_dmae_channel *chan_pdata = &pdata->channel[sh_chan->id];
- u16 __iomem *addr = shdev->dmars + chan_pdata->dmars / sizeof(u16);
+ u16 __iomem *addr = shdev->dmars;
int shift = chan_pdata->dmars_bit;
if (dmae_is_busy(sh_chan))
return -EBUSY;
+ /* in the case of a missing DMARS resource use first memory window */
+ if (!addr)
+ addr = (u16 __iomem *)shdev->chan_reg;
+ addr += chan_pdata->dmars / sizeof(u16);
+
__raw_writew((__raw_readw(addr) & (0xff00 >> shift)) | (val << shift),
addr);
@@ -1087,7 +1092,7 @@ static int __init sh_dmae_probe(struct platform_device *pdev)
return -ENODEV;
chan = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- /* DMARS area is optional, if absent, this controller cannot do slave DMA */
+ /* DMARS area is optional */
dmars = platform_get_resource(pdev, IORESOURCE_MEM, 1);
/*
* IRQ resources:
@@ -1154,7 +1159,7 @@ static int __init sh_dmae_probe(struct platform_device *pdev)
INIT_LIST_HEAD(&shdev->common.channels);
dma_cap_set(DMA_MEMCPY, shdev->common.cap_mask);
- if (dmars)
+ if (pdata->slave && pdata->slave_num)
dma_cap_set(DMA_SLAVE, shdev->common.cap_mask);
shdev->common.device_alloc_chan_resources