Commit 14c6a333 authored by Hongbo Zhang's avatar Hongbo Zhang Committed by Vinod Koul
Browse files

dmaengine: Freescale: add suspend resume functions for DMA driver 



This patch adds suspend and resume functions for Freescale DMA driver.

Signed-off-by: default avatarHongbo Zhang <hongbo.zhang@freescale.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 2baff570

drivers/dma/fsldma.c

+77 −0
Original line number Diff line number Diff line
@@ -400,6 +400,14 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx) 


	spin_lock_bh(&chan->desc_lock);



#ifdef CONFIG_PM

	if (unlikely(chan->pm_state != RUNNING)) {

		chan_dbg(chan, "cannot submit due to suspend\n");

		spin_unlock_bh(&chan->desc_lock);

		return -1;

	}

#endif



	/*

	 * assign cookies to all of the software descriptors

	 * that make up this transaction
@@ -1221,6 +1229,9 @@ static int fsl_dma_chan_probe(struct fsldma_device *fdev, 
	INIT_LIST_HEAD(&chan->ld_pending);

	INIT_LIST_HEAD(&chan->ld_running);

	chan->idle = true;

#ifdef CONFIG_PM

	chan->pm_state = RUNNING;

#endif



	chan->common.device = &fdev->common;

	dma_cookie_init(&chan->common);
@@ -1360,6 +1371,69 @@ static int fsldma_of_remove(struct platform_device *op) 
	return 0;

}



#ifdef CONFIG_PM

static int fsldma_suspend_late(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct fsldma_device *fdev = platform_get_drvdata(pdev);

	struct fsldma_chan *chan;

	int i;



	for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {

		chan = fdev->chan[i];

		if (!chan)

			continue;



		spin_lock_bh(&chan->desc_lock);

		if (unlikely(!chan->idle))

			goto out;

		chan->regs_save.mr = get_mr(chan);

		chan->pm_state = SUSPENDED;

		spin_unlock_bh(&chan->desc_lock);

	}

	return 0;



out:

	for (; i >= 0; i--) {

		chan = fdev->chan[i];

		if (!chan)

			continue;

		chan->pm_state = RUNNING;

		spin_unlock_bh(&chan->desc_lock);

	}

	return -EBUSY;

}



static int fsldma_resume_early(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct fsldma_device *fdev = platform_get_drvdata(pdev);

	struct fsldma_chan *chan;

	u32 mode;

	int i;



	for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {

		chan = fdev->chan[i];

		if (!chan)

			continue;



		spin_lock_bh(&chan->desc_lock);

		mode = chan->regs_save.mr

			& ~FSL_DMA_MR_CS & ~FSL_DMA_MR_CC & ~FSL_DMA_MR_CA;

		set_mr(chan, mode);

		chan->pm_state = RUNNING;

		spin_unlock_bh(&chan->desc_lock);

	}



	return 0;

}



static const struct dev_pm_ops fsldma_pm_ops = {

	.suspend_late	= fsldma_suspend_late,

	.resume_early	= fsldma_resume_early,

};

#endif



static const struct of_device_id fsldma_of_ids[] = {

	{ .compatible = "fsl,elo3-dma", },

	{ .compatible = "fsl,eloplus-dma", },
@@ -1372,6 +1446,9 @@ static struct platform_driver fsldma_of_driver = { 
		.name = "fsl-elo-dma",

		.owner = THIS_MODULE,

		.of_match_table = fsldma_of_ids,

#ifdef CONFIG_PM

		.pm = &fsldma_pm_ops,

#endif

	},

	.probe = fsldma_of_probe,

	.remove = fsldma_of_remove,

drivers/dma/fsldma.h

+15 −0
Original line number Diff line number Diff line
@@ -134,6 +134,17 @@ struct fsldma_device { 
#define FSL_DMA_CHAN_PAUSE_EXT	0x00001000

#define FSL_DMA_CHAN_START_EXT	0x00002000



#ifdef CONFIG_PM

struct fsldma_chan_regs_save {

	u32 mr;

};



enum fsldma_pm_state {

	RUNNING = 0,

	SUSPENDED,

};

#endif



struct fsldma_chan {

	char name[8];			/* Channel name */

	struct fsldma_chan_regs __iomem *regs;
@@ -148,6 +159,10 @@ struct fsldma_chan { 
	struct tasklet_struct tasklet;

	u32 feature;

	bool idle;			/* DMA controller is idle */

#ifdef CONFIG_PM

	struct fsldma_chan_regs_save regs_save;

	enum fsldma_pm_state pm_state;

#endif



	void (*toggle_ext_pause)(struct fsldma_chan *fsl_chan, int enable);

	void (*toggle_ext_start)(struct fsldma_chan *fsl_chan, int enable);