Commit 96a299d2 authored by Sricharan R's avatar Sricharan R Committed by Will Deacon
Browse files

iommu/arm-smmu: Add pm_runtime/sleep ops 



The smmu needs to be functional only when the respective
master's using it are active. The device_link feature
helps to track such functional dependencies, so that the
iommu gets powered when the master device enables itself
using pm_runtime. So by adapting the smmu driver for
runtime pm, above said dependency can be addressed.

This patch adds the pm runtime/sleep callbacks to the
driver and the corresponding bulk clock handling for all
the clocks needed by smmu.

Also, while we enable the runtime pm, add a pm sleep suspend
callback that pushes devices to low power state by turning
the clocks off in a system sleep.
Add corresponding clock enable path in resume callback as well.

Signed-off-by: default avatarSricharan R <sricharan@codeaurora.org>
Signed-off-by: default avatarArchit Taneja <architt@codeaurora.org>
[Thor: Rework to get clocks from device tree]
Signed-off-by: default avatarThor Thayer <thor.thayer@linux.intel.com>
[vivek: rework for clock and pm ops]
Signed-off-by: default avatarVivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: default avatarTomasz Figa <tfiga@chromium.org>
Tested-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
Tested-by: default avatarThor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent a868e853

drivers/iommu/arm-smmu.c

+55 −3
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ 
#include <linux/of_iommu.h>

#include <linux/pci.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>

#include <linux/slab.h>

#include <linux/spinlock.h>
@@ -206,6 +207,8 @@ struct arm_smmu_device { 
	u32				num_global_irqs;

	u32				num_context_irqs;

	unsigned int			*irqs;

	struct clk_bulk_data		*clks;

	int				num_clks;



	u32				cavium_id_base; /* Specific to Cavium */
@@ -1947,7 +1950,7 @@ struct arm_smmu_match_data { 
};



#define ARM_SMMU_MATCH_DATA(name, ver, imp)	\

static struct arm_smmu_match_data name = { .version = ver, .model = imp }

static const struct arm_smmu_match_data name = { .version = ver, .model = imp }



ARM_SMMU_MATCH_DATA(smmu_generic_v1, ARM_SMMU_V1, GENERIC_SMMU);

ARM_SMMU_MATCH_DATA(smmu_generic_v2, ARM_SMMU_V2, GENERIC_SMMU);
@@ -2150,6 +2153,17 @@ static int arm_smmu_device_probe(struct platform_device *pdev) 
		smmu->irqs[i] = irq;

	}



	err = devm_clk_bulk_get_all(dev, &smmu->clks);

	if (err < 0) {

		dev_err(dev, "failed to get clocks %d\n", err);

		return err;

	}

	smmu->num_clks = err;



	err = clk_bulk_prepare_enable(smmu->num_clks, smmu->clks);

	if (err)

		return err;



	err = arm_smmu_device_cfg_probe(smmu);

	if (err)

		return err;
@@ -2236,6 +2250,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev) 


	/* Turn the thing off */

	writel(sCR0_CLIENTPD, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);



	clk_bulk_disable_unprepare(smmu->num_clks, smmu->clks);



	return 0;

}
@@ -2244,15 +2261,50 @@ static void arm_smmu_device_shutdown(struct platform_device *pdev) 
	arm_smmu_device_remove(pdev);

}



static int __maybe_unused arm_smmu_pm_resume(struct device *dev)

static int __maybe_unused arm_smmu_runtime_resume(struct device *dev)

{

	struct arm_smmu_device *smmu = dev_get_drvdata(dev);

	int ret;



	ret = clk_bulk_enable(smmu->num_clks, smmu->clks);

	if (ret)

		return ret;



	arm_smmu_device_reset(smmu);



	return 0;

}



static SIMPLE_DEV_PM_OPS(arm_smmu_pm_ops, NULL, arm_smmu_pm_resume);

static int __maybe_unused arm_smmu_runtime_suspend(struct device *dev)

{

	struct arm_smmu_device *smmu = dev_get_drvdata(dev);



	clk_bulk_disable(smmu->num_clks, smmu->clks);



	return 0;

}



static int __maybe_unused arm_smmu_pm_resume(struct device *dev)

{

	if (pm_runtime_suspended(dev))

		return 0;



	return arm_smmu_runtime_resume(dev);

}



static int __maybe_unused arm_smmu_pm_suspend(struct device *dev)

{

	if (pm_runtime_suspended(dev))

		return 0;



	return arm_smmu_runtime_suspend(dev);

}



static const struct dev_pm_ops arm_smmu_pm_ops = {

	SET_SYSTEM_SLEEP_PM_OPS(arm_smmu_pm_suspend, arm_smmu_pm_resume)

	SET_RUNTIME_PM_OPS(arm_smmu_runtime_suspend,

			   arm_smmu_runtime_resume, NULL)

};



static struct platform_driver arm_smmu_driver = {

	.driver	= {

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