From: Sricharan R <sricharan@xxxxxxxxxxxxxx>
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: Sricharan R <sricharan@xxxxxxxxxxxxxx>
Signed-off-by: Archit Taneja <architt@xxxxxxxxxxxxxx>
[Thor: Rework to get clocks from device tree]
Signed-off-by: Thor Thayer <thor.thayer@xxxxxxxxxxxxxxx>
[vivek: rework for clock and pm ops]
Signed-off-by: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>
Reviewed-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
Tested-by: Thor Thayer <thor.thayer@xxxxxxxxxxxxxxx>
---
Changes since v18:
- Replaced the entire clock bulk data filling and handling with
devm_clk_bulk_get_all().
drivers/iommu/arm-smmu.c | 58 +++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 55 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 5a28ae892504..602b67d4f2d6 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -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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