[PATCH v5 2/6] iommu/arm-smmu: Add pm_runtime/sleep ops

Vivek Gautam
2018-01-09T10:02:22Z

From: Sricharan R <sricharan@codeaurora.org>

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 also the functions to parse the smmu clocks
from DT and enable them in resume/suspend.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
[vivek: Clock rework to request bulk of clocks]
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
---
drivers/iommu/arm-smmu.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 53 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 78d4c6b8f1ba..21acffe91a1c 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>

@@ -205,6 +206,9 @@ struct arm_smmu_device {
u32 num_global_irqs;
u32 num_context_irqs;
unsigned int *irqs;
+ struct clk_bulk_data *clocks;
+ int num_clks;
+ const char * const *clk_names;

u32 cavium_id_base; /* Specific to Cavium */

@@ -1685,6 +1689,25 @@ static int arm_smmu_id_size_to_bits(int size)
}
}

+static int arm_smmu_init_clocks(struct arm_smmu_device *smmu)
+{
+ int i;
+ int num = smmu->num_clks;
+
+ if (num < 1)
+ return 0;
+
+ smmu->clocks = devm_kcalloc(smmu->dev, num,
+ sizeof(*smmu->clocks), GFP_KERNEL);
+ if (!smmu->clocks)
+ return -ENOMEM;
+
+ for (i = 0; i < num; i++)
+ smmu->clocks[i].id = smmu->clk_names[i];
+
+ return devm_clk_bulk_get(smmu->dev, num, smmu->clocks);
+}
+
static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
{
unsigned long size;
@@ -1897,10 +1920,12 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
struct arm_smmu_match_data {
enum arm_smmu_arch_version version;
enum arm_smmu_implementation model;
+ const char * const *clks;
+ int num_clks;
};

#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);
@@ -2001,6 +2026,8 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev,
data = of_device_get_match_data(dev);
smmu->version = data->version;
smmu->model = data->model;
+ smmu->clk_names = data->clks;
+ smmu->num_clks = data->num_clks;

parse_driver_options(smmu);

@@ -2099,6 +2126,10 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
smmu->irqs[i] = irq;
}

+ err = arm_smmu_init_clocks(smmu);
+ if (err)
+ return err;
+
err = arm_smmu_device_cfg_probe(smmu);
if (err)
return err;
@@ -2197,7 +2228,27 @@ static int __maybe_unused arm_smmu_pm_resume(struct device *dev)
return 0;
}

-static SIMPLE_DEV_PM_OPS(arm_smmu_pm_ops, NULL, arm_smmu_pm_resume);
+static int __maybe_unused arm_smmu_runtime_resume(struct device *dev)
+{
+ struct arm_smmu_device *smmu = dev_get_drvdata(dev);
+
+ return clk_bulk_prepare_enable(smmu->num_clks, smmu->clocks);
+}
+
+static int __maybe_unused arm_smmu_runtime_suspend(struct device *dev)
+{
+ struct arm_smmu_device *smmu = dev_get_drvdata(dev);
+
+ clk_bulk_disable_unprepare(smmu->num_clks, smmu->clocks);
+
+ return 0;
+}
+
+static const struct dev_pm_ops arm_smmu_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(NULL, 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 = {