From: Sricharan R <sricha...@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 <sricha...@codeaurora.org> Signed-off-by: Archit Taneja <arch...@codeaurora.org> [vivek: Clock rework to request bulk of clocks] Signed-off-by: Vivek Gautam <vivek.gau...@codeaurora.org> --- drivers/iommu/arm-smmu.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 58 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index ffc152c36002..c8b16f53f597 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 +206,8 @@ 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 */ @@ -1902,10 +1905,12 @@ 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); @@ -1924,6 +1929,23 @@ static const struct of_device_id arm_smmu_of_match[] = { }; MODULE_DEVICE_TABLE(of, arm_smmu_of_match); +static void arm_smmu_fill_clk_data(struct arm_smmu_device *smmu, + const char * const *clks) +{ + int i; + + if (smmu->num_clks < 1) + return; + + smmu->clks = devm_kcalloc(smmu->dev, smmu->num_clks, + sizeof(*smmu->clks), GFP_KERNEL); + if (!smmu->clks) + return; + + for (i = 0; i < smmu->num_clks; i++) + smmu->clks[i].id = clks[i]; +} + #ifdef CONFIG_ACPI static int acpi_smmu_get_data(u32 model, struct arm_smmu_device *smmu) { @@ -2006,6 +2028,9 @@ 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->num_clks = data->num_clks; + + arm_smmu_fill_clk_data(smmu, data->clks); parse_driver_options(smmu); @@ -2104,6 +2129,14 @@ static int arm_smmu_device_probe(struct platform_device *pdev) smmu->irqs[i] = irq; } + err = devm_clk_bulk_get(smmu->dev, smmu->num_clks, smmu->clks); + if (err) + return err; + + err = clk_bulk_prepare(smmu->num_clks, smmu->clks); + if (err) + return err; + err = arm_smmu_device_cfg_probe(smmu); if (err) return err; @@ -2186,6 +2219,9 @@ 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_unprepare(smmu->num_clks, smmu->clks); + return 0; } @@ -2202,7 +2238,27 @@ 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_enable(smmu->num_clks, smmu->clks); +} + +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 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 = { -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu