Commit 99d9bf4e authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Vinod Koul
Browse files

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: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 2540f74b

drivers/dma/dw/core.c

+35 −25
Original line number Diff line number Diff line
@@ -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;

drivers/dma/dw/regs.h

+1 −0
Original line number Diff line number Diff line
@@ -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;