Commit 3d68bbb8 authored by Hector Martin's avatar Hector Martin Committed by Joerg Roedel
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iommu: dart: Add suspend/resume support 



We need to save/restore the TCR/TTBR registers, since they are lost
on power gate.

Reviewed-by: default avatarSven Peter <sven@svenpeter.dev>
Signed-off-by: default avatarHector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20230113105029.26654-3-marcan@marcan.st


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 659bf8e5

drivers/iommu/apple-dart.c

+43 −0
Original line number Diff line number Diff line
@@ -121,6 +121,9 @@ struct apple_dart { 


	struct iommu_group *sid2group[DART_MAX_STREAMS];

	struct iommu_device iommu;



	u32 save_tcr[DART_MAX_STREAMS];

	u32 save_ttbr[DART_MAX_STREAMS][DART_MAX_TTBR];

};



/*
@@ -932,6 +935,45 @@ static const struct apple_dart_hw apple_dart_hw_t6000 = { 
	.fmt = APPLE_DART2,

};



static __maybe_unused int apple_dart_suspend(struct device *dev)

{

	struct apple_dart *dart = dev_get_drvdata(dev);

	unsigned int sid, idx;



	for (sid = 0; sid < DART_MAX_STREAMS; sid++) {

		dart->save_tcr[sid] = readl_relaxed(dart->regs + DART_TCR(sid));

		for (idx = 0; idx < DART_MAX_TTBR; idx++)

			dart->save_ttbr[sid][idx] =

				readl(dart->regs + DART_TTBR(sid, idx));

	}



	return 0;

}



static __maybe_unused int apple_dart_resume(struct device *dev)

{

	struct apple_dart *dart = dev_get_drvdata(dev);

	unsigned int sid, idx;

	int ret;



	ret = apple_dart_hw_reset(dart);

	if (ret) {

		dev_err(dev, "Failed to reset DART on resume\n");

		return ret;

	}



	for (sid = 0; sid < DART_MAX_STREAMS; sid++) {

		for (idx = 0; idx < DART_MAX_TTBR; idx++)

			writel(dart->save_ttbr[sid][idx],

			       dart->regs + DART_TTBR(sid, idx));

		writel(dart->save_tcr[sid], dart->regs + DART_TCR(sid));

	}



	return 0;

}



DEFINE_SIMPLE_DEV_PM_OPS(apple_dart_pm_ops, apple_dart_suspend, apple_dart_resume);



static const struct of_device_id apple_dart_of_match[] = {

	{ .compatible = "apple,t8103-dart", .data = &apple_dart_hw_t8103 },

	{ .compatible = "apple,t6000-dart", .data = &apple_dart_hw_t6000 },
@@ -944,6 +986,7 @@ static struct platform_driver apple_dart_driver = { 
		.name			= "apple-dart",

		.of_match_table		= apple_dart_of_match,

		.suppress_bind_attrs    = true,

		.pm			= pm_sleep_ptr(&apple_dart_pm_ops),

	},

	.probe	= apple_dart_probe,

	.remove	= apple_dart_remove,