diff options
| author | Dmitry Osipenko <digetx@gmail.com> | 2017-11-16 20:11:06 +0300 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2017-11-29 17:05:05 +0300 |
| commit | f6160f359846408056c2646f1dbb4ea098930fee (patch) | |
| tree | a38c94208363cf0177df714a1a84f5ae83c7285b /drivers/dma/tegra20-apb-dma.c | |
| parent | 4fbd8d194f06c8a3fd2af1ce560ddb31f7ec8323 (diff) | |
| download | linux-f6160f359846408056c2646f1dbb4ea098930fee.tar.xz | |
dmaengine: tegra-apb: Support non-flow controlled slave configuration
This allows DMA client to issue a non-flow controlled TX. In particular
it is needed for the fuse driver that reads fuse registers using APBDMA
to workaround a HW bug that results in hang when CPU and DMA perform
simultaneous access to fuse peripheral.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/tegra20-apb-dma.c')
| -rw-r--r-- | drivers/dma/tegra20-apb-dma.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index b9d75a54c896..9a558e30c461 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -353,7 +353,8 @@ static int tegra_dma_slave_config(struct dma_chan *dc, } memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig)); - if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID) { + if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID && + sconfig->device_fc) { if (sconfig->slave_id > TEGRA_APBDMA_CSR_REQ_SEL_MASK) return -EINVAL; tdc->slave_id = sconfig->slave_id; @@ -970,8 +971,13 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg( TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT; ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32; - csr |= TEGRA_APBDMA_CSR_ONCE | TEGRA_APBDMA_CSR_FLOW; - csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT; + csr |= TEGRA_APBDMA_CSR_ONCE; + + if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) { + csr |= TEGRA_APBDMA_CSR_FLOW; + csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT; + } + if (flags & DMA_PREP_INTERRUPT) csr |= TEGRA_APBDMA_CSR_IE_EOC; @@ -1110,10 +1116,13 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic( TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT; ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32; - csr |= TEGRA_APBDMA_CSR_FLOW; + if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) { + csr |= TEGRA_APBDMA_CSR_FLOW; + csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT; + } + if (flags & DMA_PREP_INTERRUPT) csr |= TEGRA_APBDMA_CSR_IE_EOC; - csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT; apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1; |