[PATCH v5 5/6] iommu/arm-smmu: Add support for qcom,smmu-v2 variant

Vivek Gautam
2018-01-09T10:02:45Z

qcom,smmu-v2 is an arm,smmu-v2 implementation with specific
clock and power requirements. This smmu core is used with
multiple masters on msm8996, viz. mdss, video, etc.
Add bindings for the same.

Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
---

* Major change in this patch -
Changed compatible string from 'qcom,msm8996-smmu-v2' to
'qcom,smmu-v2' to reflect the IP version rather than the
platform on which it is used.
The same IP is used across multiple platforms including msm8996,
and sdm845 etc.

.../devicetree/bindings/iommu/arm,smmu.txt | 35 ++++++++++++++++++++++
drivers/iommu/arm-smmu.c | 13 ++++++++
2 files changed, 48 insertions(+)

diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
index 8a6ffce12af5..e4951288c87c 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
@@ -17,6 +17,7 @@ conditions.
"arm,mmu-401"
"arm,mmu-500"
"cavium,smmu-v2"
+ "qcom,smmu-v2"

depending on the particular implementation and/or the
version of the architecture implemented.
@@ -71,6 +72,23 @@ conditions.
or using stream matching with #iommu-cells = <2>, and
may be ignored if present in such cases.

+- clock-names: Should be "bus", and "iface" for "qcom,smmu-v2"
+ implementation.
+
+ "bus" clock for "qcom,smmu-v2" is required for downstream
+ bus access and for the smmu ptw.
+
+ "iface" clock is required to access smmu's registers through
+ the TCU's programming interface.
+
+- clocks: Phandles for respective clocks described by clock-names.
+
+- power-domains: Phandles to SMMU's power domain specifier. This is
+ required even if SMMU belongs to the master's power
+ domain, as the SMMU will have to be enabled and
+ accessed before master gets enabled and linked to its
+ SMMU.
+
** Deprecated properties:

- mmu-masters (deprecated in favour of the generic "iommus" binding) :
@@ -137,3 +155,20 @@ conditions.
iommu-map = <0 &smmu3 0 0x400>;
...
};
+
+ /* Qcom's arm,smmu-v2 implementation */
+ smmu4: iommu {
+ compatible = "qcom,smmu-v2";
+ reg = <0xd00000 0x10000>;
+
+ #global-interrupts = <1>;
+ interrupts = <GIC_SPI 73 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 320 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 321 IRQ_TYPE_LEVEL_HIGH>;
+ #iommu-cells = <1>;
+ power-domains = <&mmcc MDSS_GDSC>;
+
+ clocks = <&mmcc SMMU_MDP_AXI_CLK>,
+ <&mmcc SMMU_MDP_AHB_CLK>;
+ clock-names = "bus", "iface";
+ };
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 33bbcfedb896..2ade214c41bc 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -119,6 +119,7 @@ enum arm_smmu_implementation {
GENERIC_SMMU,
ARM_MMU500,
CAVIUM_SMMUV2,
+ QCOM_SMMUV2,
};

struct arm_smmu_s2cr {
@@ -1971,6 +1972,17 @@ struct arm_smmu_match_data {
ARM_SMMU_MATCH_DATA(arm_mmu500, ARM_SMMU_V2, ARM_MMU500);
ARM_SMMU_MATCH_DATA(cavium_smmuv2, ARM_SMMU_V2, CAVIUM_SMMUV2);

+static const char * const qcom_smmuv2_clks[] = {
+ "bus", "iface",
+};
+
+static const struct arm_smmu_match_data qcom_smmuv2 = {
+ .version = ARM_SMMU_V2,
+ .model = QCOM_SMMUV2,
+ .clks = qcom_smmuv2_clks,
+ .num_clks = ARRAY_SIZE(qcom_smmuv2_clks),
+};
+
static const struct of_device_id arm_smmu_of_match[] = {
{ .compatible = "arm,smmu-v1", .data = &smmu_generic_v1 },
{ .compatible = "arm,smmu-v2", .data = &smmu_generic_v2 },
@@ -1978,6 +1990,7 @@ struct arm_smmu_match_data {
{ .compatible = "arm,mmu-401", .data = &arm_mmu401 },
{ .compatible = "arm,mmu-500", .data = &arm_mmu500 },
{ .compatible = "cavium,smmu-v2", .data = &cavium_smmuv2 },
+ { .compatible = "qcom,smmu-v2", .data = &qcom_smmuv2 },
{ },
};
MODULE_DEVICE_TABLE(of, arm_smmu_of_match);