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diff --git a/Documentation/devicetree/bindings/interconnect/samsung,exynos-bus.yaml b/Documentation/devicetree/bindings/interconnect/samsung,exynos-bus.yaml new file mode 100644 index 000000000..ad9ed596d --- /dev/null +++ b/Documentation/devicetree/bindings/interconnect/samsung,exynos-bus.yaml @@ -0,0 +1,290 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/interconnect/samsung,exynos-bus.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Samsung Exynos SoC Bus and Interconnect + +maintainers: + - Chanwoo Choi <cw00.choi@samsung.com> + - Krzysztof Kozlowski <krzk@kernel.org> + +description: | + The Samsung Exynos SoC has many buses for data transfer between DRAM and + sub-blocks in SoC. Most Exynos SoCs share the common architecture for buses. + Generally, each bus of Exynos SoC includes a source clock and a power line, + which are able to change the clock frequency of the bus in runtime. To + monitor the usage of each bus in runtime, the driver uses the PPMU (Platform + Performance Monitoring Unit), which is able to measure the current load of + sub-blocks. + + The Exynos SoC includes the various sub-blocks which have the each AXI bus. + The each AXI bus has the owned source clock but, has not the only owned power + line. The power line might be shared among one more sub-blocks. So, we can + divide into two type of device as the role of each sub-block. There are two + type of bus devices as following:: + - parent bus device + - passive bus device + + Basically, parent and passive bus device share the same power line. The + parent bus device can only change the voltage of shared power line and the + rest bus devices (passive bus device) depend on the decision of the parent + bus device. If there are three blocks which share the VDD_xxx power line, + Only one block should be parent device and then the rest blocks should depend + on the parent device as passive device. + + VDD_xxx |--- A block (parent) + |--- B block (passive) + |--- C block (passive) + + There are a little different composition among Exynos SoC because each Exynos + SoC has different sub-blocks. Therefore, such difference should be specified + in devicetree file instead of each device driver. In result, this driver is + able to support the bus frequency for all Exynos SoCs. + + Detailed correlation between sub-blocks and power line according + to Exynos SoC:: + - In case of Exynos3250, there are two power line as following:: + VDD_MIF |--- DMC (Dynamic Memory Controller) + + VDD_INT |--- LEFTBUS (parent device) + |--- PERIL + |--- MFC + |--- G3D + |--- RIGHTBUS + |--- PERIR + |--- FSYS + |--- LCD0 + |--- PERIR + |--- ISP + |--- CAM + + - MIF bus's frequency/voltage table + ----------------------- + |Lv| Freq | Voltage | + ----------------------- + |L1| 50000 |800000 | + |L2| 100000 |800000 | + |L3| 134000 |800000 | + |L4| 200000 |825000 | + |L5| 400000 |875000 | + ----------------------- + + - INT bus's frequency/voltage table + ---------------------------------------------------------- + |Block|LEFTBUS|RIGHTBUS|MCUISP |ISP |PERIL ||VDD_INT | + | name| |LCD0 | | | || | + | | |FSYS | | | || | + | | |MFC | | | || | + ---------------------------------------------------------- + |Mode |*parent|passive |passive|passive|passive|| | + ---------------------------------------------------------- + |Lv |Frequency ||Voltage | + ---------------------------------------------------------- + |L1 |50000 |50000 |50000 |50000 |50000 ||900000 | + |L2 |80000 |80000 |80000 |80000 |80000 ||900000 | + |L3 |100000 |100000 |100000 |100000 |100000 ||1000000 | + |L4 |134000 |134000 |200000 |200000 | ||1000000 | + |L5 |200000 |200000 |400000 |300000 | ||1000000 | + ---------------------------------------------------------- + + - In case of Exynos4210, there is one power line as following:: + VDD_INT |--- DMC (parent device, Dynamic Memory Controller) + |--- LEFTBUS + |--- PERIL + |--- MFC(L) + |--- G3D + |--- TV + |--- LCD0 + |--- RIGHTBUS + |--- PERIR + |--- MFC(R) + |--- CAM + |--- FSYS + |--- GPS + |--- LCD0 + |--- LCD1 + + - In case of Exynos4x12, there are two power line as following:: + VDD_MIF |--- DMC (Dynamic Memory Controller) + + VDD_INT |--- LEFTBUS (parent device) + |--- PERIL + |--- MFC(L) + |--- G3D + |--- TV + |--- IMAGE + |--- RIGHTBUS + |--- PERIR + |--- MFC(R) + |--- CAM + |--- FSYS + |--- GPS + |--- LCD0 + |--- ISP + + - In case of Exynos5422, there are two power line as following:: + VDD_MIF |--- DREX 0 (parent device, DRAM EXpress controller) + |--- DREX 1 + + VDD_INT |--- NoC_Core (parent device) + |--- G2D + |--- G3D + |--- DISP1 + |--- NoC_WCORE + |--- GSCL + |--- MSCL + |--- ISP + |--- MFC + |--- GEN + |--- PERIS + |--- PERIC + |--- FSYS + |--- FSYS2 + + - In case of Exynos5433, there is VDD_INT power line as following:: + VDD_INT |--- G2D (parent device) + |--- MSCL + |--- GSCL + |--- JPEG + |--- MFC + |--- HEVC + |--- BUS0 + |--- BUS1 + |--- BUS2 + |--- PERIS (Fixed clock rate) + |--- PERIC (Fixed clock rate) + |--- FSYS (Fixed clock rate) + +properties: + compatible: + enum: + - samsung,exynos-bus + + clocks: + maxItems: 1 + + clock-names: + items: + - const: bus + + devfreq: + $ref: /schemas/types.yaml#/definitions/phandle + description: + Parent bus device. Valid and required only for the passive bus devices. + + devfreq-events: + $ref: /schemas/types.yaml#/definitions/phandle-array + minItems: 1 + maxItems: 4 + description: + Devfreq-event device to monitor the current utilization of buses. Valid + and required only for the parent bus devices. + + exynos,saturation-ratio: + $ref: /schemas/types.yaml#/definitions/uint32 + description: + Percentage value which is used to calibrate the performance count against + total cycle count. Valid only for the parent bus devices. + + '#interconnect-cells': + const: 0 + + interconnects: + minItems: 1 + maxItems: 2 + + operating-points-v2: true + + samsung,data-clock-ratio: + $ref: /schemas/types.yaml#/definitions/uint32 + default: 8 + description: + Ratio of the data throughput in B/s to minimum data clock frequency in + Hz. + + vdd-supply: + description: + Main bus power rail. Valid and required only for the parent bus devices. + +required: + - compatible + - clocks + - clock-names + - operating-points-v2 + +additionalProperties: false + +examples: + - | + #include <dt-bindings/clock/exynos3250.h> + + bus-dmc { + compatible = "samsung,exynos-bus"; + clocks = <&cmu_dmc CLK_DIV_DMC>; + clock-names = "bus"; + operating-points-v2 = <&bus_dmc_opp_table>; + devfreq-events = <&ppmu_dmc0_3>, <&ppmu_dmc1_3>; + vdd-supply = <&buck1_reg>; + }; + + ppmu_dmc0: ppmu@106a0000 { + compatible = "samsung,exynos-ppmu"; + reg = <0x106a0000 0x2000>; + events { + ppmu_dmc0_3: ppmu-event3-dmc0 { + event-name = "ppmu-event3-dmc0"; + }; + }; + }; + + bus_leftbus: bus-leftbus { + compatible = "samsung,exynos-bus"; + clocks = <&cmu CLK_DIV_GDL>; + clock-names = "bus"; + operating-points-v2 = <&bus_leftbus_opp_table>; + devfreq-events = <&ppmu_leftbus_3>, <&ppmu_rightbus_3>; + vdd-supply = <&buck3_reg>; + }; + + bus-rightbus { + compatible = "samsung,exynos-bus"; + clocks = <&cmu CLK_DIV_GDR>; + clock-names = "bus"; + operating-points-v2 = <&bus_leftbus_opp_table>; + devfreq = <&bus_leftbus>; + }; + + - | + dmc: bus-dmc { + compatible = "samsung,exynos-bus"; + clocks = <&clock CLK_DIV_DMC>; + clock-names = "bus"; + operating-points-v2 = <&bus_dmc_opp_table>; + samsung,data-clock-ratio = <4>; + #interconnect-cells = <0>; + devfreq-events = <&ppmu_dmc0_3>, <&ppmu_dmc1_3>; + vdd-supply = <&buck1_reg>; + }; + + leftbus: bus-leftbus { + compatible = "samsung,exynos-bus"; + clocks = <&clock CLK_DIV_GDL>; + clock-names = "bus"; + operating-points-v2 = <&bus_leftbus_opp_table>; + interconnects = <&dmc>; + #interconnect-cells = <0>; + devfreq-events = <&ppmu_leftbus_3>, <&ppmu_rightbus_3>; + vdd-supply = <&buck3_reg>; + }; + + display: bus-display { + compatible = "samsung,exynos-bus"; + clocks = <&clock CLK_DIV_ACLK_266>; + clock-names = "bus"; + operating-points-v2 = <&bus_display_opp_table>; + interconnects = <&leftbus &dmc>; + #interconnect-cells = <0>; + devfreq = <&leftbus>; + }; |