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| author | Magnus Damm <damm@opensource.se> | 2011-05-24 10:31:12 +0000 |
|---|---|---|
| committer | Paul Mundt <lethal@linux-sh.org> | 2011-05-25 11:35:23 +0900 |
| commit | 26fc02ab5551349b2e593829a76cb44328ee7f61 (patch) | |
| tree | 3ad395f8942e2e2ad869f508434e3738ad28bf45 | |
| parent | 66ad12931d523e833516659eafcc29af9a08fff3 (diff) | |
| download | linux-3.10-26fc02ab5551349b2e593829a76cb44328ee7f61.tar.gz linux-3.10-26fc02ab5551349b2e593829a76cb44328ee7f61.tar.bz2 linux-3.10-26fc02ab5551349b2e593829a76cb44328ee7f61.zip | |
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>
| -rw-r--r-- | drivers/dma/shdma.c | 11 |
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 |