[PATCH v14 4/4] iommu/arm-smmu: Add support for qcom,smmu-v2 variant

Vivek Gautam
2018-07-27T07:02:24Z

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>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
---

Change since v13:
- No change.

.../devicetree/bindings/iommu/arm,smmu.txt | 42 ++++++++++++++++++++++
drivers/iommu/arm-smmu.c | 13 +++++++
2 files changed, 55 insertions(+)

diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
index 8a6ffce12af5..7c71a6ed465a 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
@@ -17,10 +17,19 @@ conditions.
"arm,mmu-401"
"arm,mmu-500"
"cavium,smmu-v2"
+ "qcom,<soc>-smmu-v2", "qcom,smmu-v2"

depending on the particular implementation and/or the
version of the architecture implemented.

+ A number of Qcom SoCs use qcom,smmu-v2 version of the IP.
+ "qcom,<soc>-smmu-v2" represents a soc specific compatible
+ string that should be present along with the "qcom,smmu-v2"
+ to facilitate SoC specific clocks/power connections and to
+ address specific bug fixes.
+ An example string would be -
+ "qcom,msm8996-smmu-v2", "qcom,smmu-v2".
+
- reg : Base address and size of the SMMU.

- #global-interrupts : The number of global interrupts exposed by the
@@ -71,6 +80,22 @@ conditions.
or using stream matching with #iommu-cells = <2>, and
may be ignored if present in such cases.

+- clock-names: List of the names of clocks input to the device. The
+ required list depends on particular implementation and
+ is as follows:
+ - for "qcom,smmu-v2":
+ - "bus": clock required for downstream bus access and
+ for the smmu ptw,
+ - "iface": clock required to access smmu's registers
+ through the TCU's programming interface.
+ - unspecified for other implementations.
+
+- clocks: Specifiers for all clocks listed in the clock-names property,
+ as per generic clock bindings.
+
+- power-domains: Specifiers for power domains required to be powered on for
+ the SMMU to operate, as per generic power domain bindings.
+
** Deprecated properties:

- mmu-masters (deprecated in favour of the generic "iommus" binding) :
@@ -137,3 +162,20 @@ conditions.
iommu-map = <0 &smmu3 0 0x400>;
...
};
+
+ /* Qcom's arm,smmu-v2 implementation */
+ smmu4: iommu {
+ compatible = "qcom,msm8996-smmu-v2", "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 e558abf1ecfc..2b4edba188a5 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 @@ ARM_SMMU_MATCH_DATA(arm_mmu401, ARM_SMMU_V1_64K, GENERIC_SMMU);
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 @@ static const struct of_device_id arm_smmu_of_match[] = {
{ .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);