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Commit 467017b8 authored by Guennadi Liakhovetski's avatar Guennadi Liakhovetski Committed by Paul Mundt
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dmaengine: shdma: add runtime- and system-level power management 



This patch extends and fixes runtime power management in the shdma
driver to support powering down the DMA controller and adds support
for system-level suspend and resume.

Signed-off-by: default avatarGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 2dc66667

drivers/dma/shdma.c

+68 −0
Original line number Diff line number Diff line
@@ -1255,6 +1255,8 @@ static int __init sh_dmae_probe(struct platform_device *pdev) 
	spin_unlock_irqrestore(&sh_dmae_lock, flags);



	pm_runtime_put(&pdev->dev);

	pm_runtime_disable(&pdev->dev);



	if (dmars)

		iounmap(shdev->dmars);

emapdmars:
@@ -1313,12 +1315,78 @@ static void sh_dmae_shutdown(struct platform_device *pdev) 
	sh_dmae_ctl_stop(shdev);

}



static int sh_dmae_runtime_suspend(struct device *dev)

{

	return 0;

}



static int sh_dmae_runtime_resume(struct device *dev)

{

	struct sh_dmae_device *shdev = dev_get_drvdata(dev);



	return sh_dmae_rst(shdev);

}



#ifdef CONFIG_PM

static int sh_dmae_suspend(struct device *dev)

{

	struct sh_dmae_device *shdev = dev_get_drvdata(dev);

	int i;



	for (i = 0; i < shdev->pdata->channel_num; i++) {

		struct sh_dmae_chan *sh_chan = shdev->chan[i];

		if (sh_chan->descs_allocated)

			sh_chan->pm_error = pm_runtime_put_sync(dev);

	}



	return 0;

}



static int sh_dmae_resume(struct device *dev)

{

	struct sh_dmae_device *shdev = dev_get_drvdata(dev);

	int i;



	for (i = 0; i < shdev->pdata->channel_num; i++) {

		struct sh_dmae_chan *sh_chan = shdev->chan[i];

		struct sh_dmae_slave *param = sh_chan->common.private;



		if (!sh_chan->descs_allocated)

			continue;



		if (!sh_chan->pm_error)

			pm_runtime_get_sync(dev);



		if (param) {

			const struct sh_dmae_slave_config *cfg = param->config;

			dmae_set_dmars(sh_chan, cfg->mid_rid);

			dmae_set_chcr(sh_chan, cfg->chcr);

		} else {

			dmae_init(sh_chan);

		}

	}



	return 0;

}

#else

#define sh_dmae_suspend NULL

#define sh_dmae_resume NULL

#endif



const struct dev_pm_ops sh_dmae_pm = {

	.suspend		= sh_dmae_suspend,

	.resume			= sh_dmae_resume,

	.runtime_suspend	= sh_dmae_runtime_suspend,

	.runtime_resume		= sh_dmae_runtime_resume,

};



static struct platform_driver sh_dmae_driver = {

	.remove		= __exit_p(sh_dmae_remove),

	.shutdown	= sh_dmae_shutdown,

	.driver = {

		.owner	= THIS_MODULE,

		.name	= "sh-dma-engine",

		.pm	= &sh_dmae_pm,

	},

};

drivers/dma/shdma.h

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ struct sh_dmae_chan { 
	int id;				/* Raw id of this channel */

	u32 __iomem *base;

	char dev_id[16];		/* unique name per DMAC of channel */

	int pm_error;

};



struct sh_dmae_device {