diff options
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2014-09-23 17:18:14 +0300 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2014-10-15 20:31:05 +0530 |
| commit | 99d9bf4ed27c63d5559e31d112f71af655c7182b (patch) | |
| tree | f0fc2e9d1053d98b265f38453e01cba00d1b7bd2 /drivers/dma | |
| parent | 2540f74b187e3ec0fe106b7427c4a84c955dc140 (diff) | |
| download | linux-99d9bf4ed27c63d5559e31d112f71af655c7182b.tar.gz | |
dmaengine: dw: enable and disable controller when needed
Enable controller automatically whenever first user requires for a channel and disable it when the last user gone. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/dw/core.c | 60 | ||||
| -rw-r--r-- | drivers/dma/dw/regs.h | 1 |
2 files changed, 36 insertions, 25 deletions
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index 48126380e036..244722170410 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -1094,6 +1094,31 @@ static void dwc_issue_pending(struct dma_chan *chan) spin_unlock_irqrestore(&dwc->lock, flags); } +/*----------------------------------------------------------------------*/ + +static void dw_dma_off(struct dw_dma *dw) +{ + int i; + + dma_writel(dw, CFG, 0); + + channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask); + channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask); + channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask); + channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask); + + while (dma_readl(dw, CFG) & DW_CFG_DMA_EN) + cpu_relax(); + + for (i = 0; i < dw->dma.chancnt; i++) + dw->chan[i].initialized = false; +} + +static void dw_dma_on(struct dw_dma *dw) +{ + dma_writel(dw, CFG, DW_CFG_DMA_EN); +} + static int dwc_alloc_chan_resources(struct dma_chan *chan) { struct dw_dma_chan *dwc = to_dw_dma_chan(chan); @@ -1118,6 +1143,11 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan) * doesn't mean what you think it means), and status writeback. */ + /* Enable controller here if needed */ + if (!dw->in_use) + dw_dma_on(dw); + dw->in_use |= dwc->mask; + spin_lock_irqsave(&dwc->lock, flags); i = dwc->descs_allocated; while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) { @@ -1182,6 +1212,11 @@ static void dwc_free_chan_resources(struct dma_chan *chan) spin_unlock_irqrestore(&dwc->lock, flags); + /* Disable controller in case it was a last user */ + dw->in_use &= ~dwc->mask; + if (!dw->in_use) + dw_dma_off(dw); + list_for_each_entry_safe(desc, _desc, &list, desc_node) { dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc); dma_pool_free(dw->desc_pool, desc, desc->txd.phys); @@ -1452,29 +1487,6 @@ EXPORT_SYMBOL(dw_dma_cyclic_free); /*----------------------------------------------------------------------*/ -static void dw_dma_off(struct dw_dma *dw) -{ - int i; - - dma_writel(dw, CFG, 0); - - channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask); - channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask); - channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask); - channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask); - - while (dma_readl(dw, CFG) & DW_CFG_DMA_EN) - cpu_relax(); - - for (i = 0; i < dw->dma.chancnt; i++) - dw->chan[i].initialized = false; -} - -static void dw_dma_on(struct dw_dma *dw) -{ - dma_writel(dw, CFG, DW_CFG_DMA_EN); -} - int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) { struct dw_dma *dw; @@ -1648,8 +1660,6 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) dw->dma.device_tx_status = dwc_tx_status; dw->dma.device_issue_pending = dwc_issue_pending; - dw_dma_on(dw); - err = dma_async_device_register(&dw->dma); if (err) goto err_dma_register; diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h index e8f92b28ffc2..848e232f7cc7 100644 --- a/drivers/dma/dw/regs.h +++ b/drivers/dma/dw/regs.h @@ -281,6 +281,7 @@ struct dw_dma { /* channels */ struct dw_dma_chan *chan; u8 all_chan_mask; + u8 in_use; /* hardware configuration */ unsigned char nr_masters; |