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dmaengine: dw: enable and disable controller when needed

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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>
This commit is contained in:
Andy Shevchenko 2014-09-23 17:18:14 +03:00 committed by Vinod Koul
parent 2540f74b18
commit 99d9bf4ed2
2 changed files with 36 additions and 25 deletions
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60
drivers/dma/dw/core.c
View file

@ -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;

1
drivers/dma/dw/regs.h
View file

@ -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;