79 lines
2.8 KiB
Plaintext
79 lines
2.8 KiB
Plaintext
QTI MDSS Rotator
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MDSS rotator is a rotator driver, which manages the rotator hw
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block inside the Mobile Display Subsystem.
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Required properties
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- compatible : Must be "qcom,mdss-rotator".
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- qcom,mdss-wb-count: The number of writeback block
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in the hardware
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- <name>-supply: Phandle for <name> regulator device node.
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Bus Scaling Data:
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- qcom,msm-bus,name: String property describing MDSS client.
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- qcom,msm-bus,num-cases: This is the the number of Bus Scaling use cases
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defined in the vectors property. This must be
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set to <3> for MDSS driver where use-case 0 is
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used to take off MDSS BW votes from the system.
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And use-case 1 & 2 are used in ping-pong fashion
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to generate run-time BW requests.
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- qcom,msm-bus,num-paths: This represents the number of paths in each
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Bus Scaling Usecase. This value depends on
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how many number of AXI master ports are
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dedicated to MDSS for particular chipset.
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- qcom,msm-bus,vectors-KBps: * A series of 4 cell properties, with a format
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of (src, dst, ab, ib) which is defined at
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Documentation/devicetree/bindings/arm/msm/msm_bus.txt
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* Current values of src & dst are defined at
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include/linux/msm-bus-board.h
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src values allowed for MDSS are:
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22 = MSM_BUS_MASTER_MDP_PORT0
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23 = MSM_BUS_MASTER_MDP_PORT1
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25 = MSM_BUS_MASTER_ROTATOR
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dst values allowed for MDSS are:
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512 = MSM_BUS_SLAVE_EBI_CH0
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ab: Represents aggregated bandwidth.
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ib: Represents instantaneous bandwidth.
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* Total number of 4 cell properties will be
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(number of use-cases * number of paths).
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* These values will be overridden by the driver
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based on the run-time requirements. So initial
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ab and ib values defined here are random and
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bare no logic except for the use-case 0 where ab
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and ib values needs to be 0.
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* Define realtime vector properties followed by
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non-realtime vector properties.
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Optional properties
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- qcom,mdss-has-reg-bus: Boolean property to indicate
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if rotator needs to vote for register bus. This
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property is needed starting 8996
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- qcom,mdss-has-ubwc: Boolean property to indicate
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if the hw supports universal
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bandwidth compression (ubwc)
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- qcom,mdss-has-downscale Boolean property to indicate
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if the hw supports downscale
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Example:
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mdss_rotator: qcom,mdss_rotator {
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compatible = "qcom,mdss_rotator";
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qcom,mdss-has-downscale;
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qcom,mdss-has-ubwc;
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qcom,mdss-wb-count = <2>;
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qcom,mdss-has-reg-bus;
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/* Bus Scale Settings */
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qcom,msm-bus,name = "mdss_rotator";
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qcom,msm-bus,num-cases = <3>;
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qcom,msm-bus,num-paths = <1>;
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qcom,mdss-num-nrt-paths = <1>;
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qcom,msm-bus,vectors-KBps =
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<25 512 0 0>,
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<25 512 0 6400000>,
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<25 512 0 6400000>;
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vdd-supply = <&gdsc_mdss>;
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gdsc-mmagic-mdss-supply = <&gdsc_mmagic_mdss>;
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qcom,supply-names = "vdd", "gdsc-mmagic-mdss";
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};
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