Commit 2dcdf570 authored by Peter Ujfalusi's avatar Peter Ujfalusi Committed by Mark Brown
Browse files

dmaengine: omap: Add support for pause/resume in cyclic dma mode 



The audio stack used omap_stop_dma/omap_start_dma to pause/resume the DMA.
This method has been used for years on OMAP based products.
We only allow pause/resume when the DMA has been configured in cyclic mode
which is used by the audio stack.

Signed-off-by: default avatarPeter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: default avatarVinod Koul <vinod.koul@linux.intel.com>
Tested-by: default avatarJanusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent ccffa387

drivers/dma/omap-dma.c

+25 −5
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ struct omap_chan { 
	struct dma_slave_config	cfg;

	unsigned dma_sig;

	bool cyclic;

	bool paused;



	int dma_ch;

	struct omap_desc *desc;
@@ -470,11 +471,14 @@ static int omap_dma_terminate_all(struct omap_chan *c) 
	 */

	if (c->desc) {

		c->desc = NULL;

		/* Avoid stopping the dma twice */

		if (!c->paused)

			omap_stop_dma(c->dma_ch);

	}



	if (c->cyclic) {

		c->cyclic = false;

		c->paused = false;

		omap_dma_unlink_lch(c->dma_ch, c->dma_ch);

	}
@@ -487,14 +491,30 @@ static int omap_dma_terminate_all(struct omap_chan *c) 


static int omap_dma_pause(struct omap_chan *c)

{

	/* FIXME: not supported by platform private API */

	/* Pause/Resume only allowed with cyclic mode */

	if (!c->cyclic)

		return -EINVAL;



	if (!c->paused) {

		omap_stop_dma(c->dma_ch);

		c->paused = true;

	}



	return 0;

}



static int omap_dma_resume(struct omap_chan *c)

{

	/* FIXME: not supported by platform private API */

	/* Pause/Resume only allowed with cyclic mode */

	if (!c->cyclic)

		return -EINVAL;



	if (c->paused) {

		omap_start_dma(c->dma_ch);

		c->paused = false;

	}



	return 0;

}



static int omap_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,

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