Qualcomm MDSS MDP

MDSS is Mobile Display SubSystem which implements Linux framebuffer APIs to
drive user interface to different panel interfaces. MDP driver is the core of
MDSS which manage all data paths to different panel interfaces.

Required properties
- compatible :		Must be "qcom,mdss_mdp"
- reg :			offset and length of the register set for the device.
- reg-names :		names to refer to register sets related to this device
- interrupts :		Interrupt associated with MDSS.
- vdd-supply :		Phandle for vdd regulator device node.
- qcom,max-clk-rate:	Specify maximum MDP core clock rate in hz that this
			device supports.
- qcom,mdss-pipe-vig-off:	Array of offset for MDP source surface pipes of
				type VIG, the offsets are calculated from
				register "mdp_phys" defined in reg property.
				The number of offsets defined here should
				reflect the amount of VIG pipes that can be
				active in MDP for this configuration.
- qcom,mdss-pipe-vig-fetch-id:	Array of shared memory pool fetch ids
				corresponding to the VIG pipe offsets defined in
				previous property, the amount of fetch ids
				defined should match the number of offsets
				defined in property: qcom,mdss-pipe-vig-off
- qcom,mdss-pipe-rgb-off:	Array of offsets for MDP source surface pipes of
				type RGB, the offsets are calculated from
				register "mdp_phys" defined in reg property.
				The number of offsets defined here should
				reflect the amount of RGB pipes that can be
				active in MDP for this configuration.
- qcom,mdss-pipe-rgb-fetch-id:	Array of shared memory pool fetch ids
				corresponding to the RGB pipe offsets defined in
				previous property, the amount of fetch ids
				defined should match the number of offsets
				defined in property: qcom,mdss-pipe-rgb-off
- qcom,mdss-pipe-dma-off:	Array of offsets for MDP source surface pipes of
				type DMA, the offsets are calculated from
				register "mdp_phys" defined in reg property.
				The number of offsets defined here should
				reflect the amount of DMA pipes that can be
				active in MDP for this configuration.
- qcom,mdss-pipe-dma-fetch-id:	Array of shared memory pool fetch ids
				corresponding to the DMA pipe offsets defined in
				previous property, the amount of fetch ids
				defined should match the number of offsets
				defined in property: qcom,mdss-pipe-dma-off
- qcom,mdss-smp-data:		Array of shared memory pool data. There should
				be only two values in this property. The first
				value corresponds to the number of smp blocks
				and the second is the size of each block
				present in the mdss hardware.
- qcom,mdss-ctl-off:		Array of offset addresses for the available ctl
				hw blocks within MDP, these offsets are
				calculated from register "mdp_phys" defined in
				reg property.  The number of ctl offsets defined
				here should reflect the number of control paths
				that can be configured concurrently on MDP for
				this configuration.
- qcom,mdss-wb-off:		Array of offset addresses for the progammable
				writeback blocks within MDP. The number of
				offsets defined should match the number of ctl
				blocks defined in property: qcom,mdss-ctl-off
- qcom,mdss-mixer-intf-off: 	Array of offset addresses for the available
				mixer blocks that can drive data to panel
				interfaces.
				These offsets are be calculated from register
				"mdp_phys" defined in reg property.
				The number of offsets defined should reflect the
				amount of mixers that can drive data to a panel
				interface.
- qcom,mdss-dspp-off: 		Array of offset addresses for the available dspp
				blocks. These offsets are calculated from
				regsiter "mdp_phys" defined in reg property.
				The number of dspp blocks should match the
				number of mixers driving data to interface
				defined in property: qcom,mdss-mixer-intf-off
- qcom,mdss-pingpong-off:	Array of offset addresses for the available
				pingpong blocks. These offsets are calculated
				from regsiter "mdp_phys" defined in reg property.
				The number of pingpong blocks should match the
				number of mixers driving data to interface
				defined in property: qcom,mdss-mixer-intf-off
- qcom,mdss-mixer-wb-off: 	Array of offset addresses for the available
				mixer blocks that can be drive data to writeback
				block.  These offsets will be calculated from
				register "mdp_phys" defined in reg property.
				The number of writeback mixer offsets defined
				should reflect the number of mixers that can
				drive data to a writeback block.
- qcom,mdss-intf-off:		Array of offset addresses for the available MDP
				video interface blocks that can drive data to a
				panel controller through timing engine.
				The offsets are calculated from "mdp_phys"
				defined in reg property. The number of offsets
				defiend should reflect the number of progammable
				interface blocks available in hardware.
- qcom,mdss-pref-prim-intf:	A string which indicates the configured hardware
				interface between MDP and the primary panel.
				Individual panel controller drivers initialize
				hardware based on this property.
				Based on the interfaces supported at present,
				possible values are:
				- "dsi"
				- "edp"
				- "hdmi"

Optional properties:
- vdd-cx-supply :	Phandle for vdd CX regulator device node.
- batfet-supply :	Phandle for battery FET regulator device node.
- qcom,vbif-settings :	Array with key-value pairs of constant VBIF register
			settings used to setup MDSS QoS for optimum performance.
			The key used should be offset from "vbif_phys" register
			defined in reg property.
- qcom,mdp-settings :	Array with key-value pairs of constant MDP register
			settings used to setup MDSS QoS for best performance.
			The key used should be offset from "mdp_phys" register
			defined in reg property.
- qcom,mdss-rot-block-size:	The size of a memory block (in pixels) to be used
				by the rotator. If this property is not specified,
				then a default value of 128 pixels would be used.
- qcom,mdss-has-bwc: Boolean property to indicate the presence of bandwidth
		      compression feature in the rotator.
- qcom,mdss-has-decimation: Boolean property to indicate the presence of
			    decimation feature in fetch.
- qcom,mdss-ad-off:		Array of offset addresses for the available
				Assertive Display (AD) blocks. These offsets
				are calculated from the register "mdp_phys"
				defined in reg property. The number of AD
				offsets should be less than or equal to the
				number of mixers driving interfaces defined in
				property: qcom,mdss-mixer-intf-off. Assumes
				that AD blocks are aligned with the mixer
				offsets as well (i.e. the first mixer offset
				corresponds to the same pathway as the first
				AD offset).
- qcom,mdss-has-wfd-blk: Boolean property to indicate the presence of dedicated
			writeback wfd block in MDSS as opposed to writeback
			block that is shared between rotator and wfd.
- qcom,mdss-smp-mb-per-pipe:	Maximum number of shared memory pool blocks
				restricted for a source surface pipe. If this
				property is not specified, no such restriction
				would be applied.
- qcom,mdss-pipe-rgb-fixed-mmb: Array of indexes describing fixed Memory Macro
				Blocks (MMBs) for rgb pipes. First value denotes
				total numbers of MMBs per pipe while values, if
				any, following first one denotes indexes of MMBs
				to that RGB pipe.

Optional subnodes:
Child nodes representing the frame buffer virtual devices.

Subnode properties:
- compatible :		Must be "qcom,mdss-fb"
- cell-index :		Index representing frame buffer
- qcom,mdss-mixer-swap: A boolean property that indicates if the mixer muxes
			 need to be swapped based on the target panel.
			 By default the property is not defined.
- qcom,mdss-fb-split:	 Array of splitted framebuffer size. There should
			 be only two values in this property. The values
			 correspond to the left and right size respectively.
			 MDP muxes two mixer output together before sending to
			 the panel interface and these values are used to set
			 each mixer width, so the sum of these two values
			 should be equal to the panel x-resolution.

			 Note that if the sum of two values is not equal to
			 x-resolution or this subnode itself is not defined
			 in device tree there are two cases: 1)split is not
			 enabled if framebuffer size is less than max mixer
			 width; 2) the defaut even split is enabled if frambuffer
			 size is greater than max mixer width.
- qcom,memblock-reserve: Specifies the memory location and the size reserved
			 for the framebuffer used to display the splash screen.
			 This property is required whenever the continuous splash
			 screen feature is enabled for the corresponding
			 framebuffer device.

Example:
	mdss_mdp: qcom,mdss_mdp@fd900000 {
		compatible = "qcom,mdss_mdp";
		reg = <0xfd900000 0x22100>,
			<0xfd924000 0x1000>;
		reg-names = "mdp_phys", "vbif_phys";
		interrupts = <0 72 0>;
		vdd-supply = <&gdsc_mdss>;
		vdd-cx-supply = <&pm8841_s2_corner>;
		batfet-supply = <&pm8941_chg_batif>;
		qcom,max-clk-rate = <320000000>;
		qcom,vbif-settings = <0x0004 0x00000001>,
				     <0x00D8 0x00000707>;
		qcom,mdp-settings = <0x02E0 0x000000AA>,
				    <0x02E4 0x00000055>;
		qcom,mdss-pipe-vig-off = <0x00001200 0x00001600
					  0x00001A00>;
		qcom,mdss-pipe-rgb-off = <0x00001E00 0x00002200
					  0x00002600>;
		qcom,mdss-pipe-dma-off = <0x00002A00 0x00002E00>;
		qcom,mdss-pipe-vig-fetch-id = <1 4 7>;
		qcom,mdss-pipe-rgb-fetch-id = <16 17 18>;
		qcom,mdss-pipe-dma-fetch-id = <10 13>;
		qcom,mdss-pipe-rgb-fixed-mmb =	<2 0 1>,
						<2 2 3>,
						<2 4 5>,
						<2 6 7>;
		qcom,mdss-smp-data = <22 4096>;
		qcom,mdss-rot-block-size = <64>;
		qcom,mdss-smp-mb-per-pipe = <2>;
		qcom,mdss-pref-prim-intf = "dsi";
		qcom,mdss-has-bwc;
		qcom,mdss-has-decimation;
		qcom,mdss-has-wfd-blk;

		qcom,mdss-ctl-off = <0x00000600 0x00000700 0x00000800
				     0x00000900 0x0000A00>;
		qcom,mdss-mixer-intf-off = <0x00003200 0x00003600
					    0x00003A00>;
		qcom,mdss-mixer-wb-off = <0x00003E00 0x00004200>;
		qcom,mdss-dspp-off = <0x00004600 0x00004A00 0x00004E00>;
		qcom,mdss-pingpong-off = <0x00012D00 0x00012E00 0x00012F00>;
		qcom,mdss-wb-off = <0x00011100 0x00013100 0x00015100
				    0x00017100 0x00019100>;
		qcom,mdss-intf-off = <0x00021100 0x00021300
					   0x00021500 0x00021700>;

		mdss_fb0: qcom,mdss_fb_primary {
			cell-index = <0>;
			compatible = "qcom,mdss-fb";
			qcom,mdss-mixer-swap;
			qcom,mdss-fb-split = <480 240>
		};
	};