Patchwork [PATCHv8,13/21] iommu/tegra124: smmu: optionaly AHB enables SMMU

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Submitter Hiroshi Doyu
Date May 30, 2014, 11:20 a.m.
Message ID <1401448834-32659-14-git-send-email-hdoyu@nvidia.com>
Download mbox | patch
Permalink /patch/354085/
State Superseded, archived
Headers show

Comments

Hiroshi Doyu - May 30, 2014, 11:20 a.m.
SMMU used to depend on AHB bus. AHB driver needs to be populated and
AHB_XBAR_CTRL_SMMU_INIT_DONE bit needs to be set earliear than SMMU
being populated. Later Tegra SoC (>= T124) doesn't need AHB to enable
SMMU on AHB_XBAR_CTRL for AHB_XBAR_CTRL_SMMU_INIT_DONE any more. This
setting bit is now optional, depending on DT passing ahb phandle or
not.

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
---
 drivers/iommu/tegra-smmu.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Patch

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 4a326476c364..20dddc305fb2 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -499,7 +499,10 @@  static int smmu_setup_regs(struct smmu_device *smmu)
 
 	smmu_flush_regs(smmu, 1);
 
-	return tegra_ahb_enable_smmu(smmu->ahb);
+	if (smmu->ahb)
+		return tegra_ahb_enable_smmu(smmu->ahb);
+
+	return 0;
 }
 
 static void flush_ptc_and_tlb(struct smmu_device *smmu,
@@ -1283,9 +1286,6 @@  static int tegra_smmu_probe(struct platform_device *pdev)
 		return -EINVAL;
 
 	smmu->ahb = of_parse_phandle(dev->of_node, "nvidia,ahb", 0);
-	if (!smmu->ahb)
-		return -ENODEV;
-
 	smmu->iommu.dev = dev;
 	smmu->num_as = asids;
 	smmu->iovmm_base = base;