高通mdss-dsi：多DSI控制器支持与MIPi调试详解

Qualcomm mdss-dsi

mdss-dsi is the master DSI device which supports multiple DSI host controllers that
are compatible with MIPI display serial interface specification.

Required properties:
- compatible: Must be "qcom,mdss-dsi"
- hw-config: Specifies the DSI host setup configuration
"hw-config" = "single_dsi"
"hw-config" = "dual_dsi"
"hw-config" = "split_dsi"
- ranges: The standard property which specifies the child address
space, parent address space and the length.
- vdda-supply: Phandle for vreg regulator device node.

Bus Scaling Data:
- qcom,msm-bus,name: String property describing MDSS client.
- qcom, msm-bus,num-cases: This is the number of bus scaling use cases
defined in the vectors property. This must be
set to <2> for MDSS DSI driver where use-case 0
is used to remove BW votes from the system. Use
case 1 is used to generate bandwidth requestes
when sending command packets.
- qcom,msm-bus,num-paths: This represents number of paths in each bus
scaling usecase. This value depends on number of
AXI master ports dedicated to MDSS for
particular chipset.
- qcom,msm-bus,vectors-KBps: A series of 4 cell properties, with a format
of (src, dst, ab, ib) which is defined at
Documentation/devicetree/bindings/arm/msm/msm_bus.txt.

DSI driver should always set average bandwidth
(ab) to 0 and always use instantaneous
bandwidth(ib) values.

Optional properties:
- vcca-supply: Phandle for vcca regulator device node.
- qcom,<type>-supply-entries: A node that lists the elements of the supply used by the
a particular "type" of DSI modulee. The module "types"
can be "core", "ctrl", and "phy". Within the same type,
there can be more than one instance of this binding,
in which case the entry would be appended with the
supply entry index.
e.g. qcom,ctrl-supply-entry@0
-- qcom,supply-name: name of the supply (vdd/vdda/vddio)
-- qcom,supply-min-voltage: minimum voltage level (uV)
-- qcom,supply-max-voltage: maximum voltage level (uV)
-- qcom,supply-enable-load: load drawn (uA) from enabled supply
-- qcom,supply-disable-load: load drawn (uA) from disabled supply
-- qcom,supply-pre-on-sleep: time to sleep (ms) before turning on
-- qcom,supply-post-on-sleep: time to sleep (ms) after turning on
-- qcom,supply-pre-off-sleep: time to sleep (ms) before turning off
-- qcom,supply-post-off-sleep: time to sleep (ms) after turning off
- pll-src-config Specified the source PLL for the DSI
link clocks:
"PLL0" - Clocks sourced out of DSI PLL0
"PLL1" - Clocks sourced out of DSI PLL1
This property is only valid for
certain DSI hardware configurations
mentioned in the "hw-config" binding above.
For example, in split_dsi config, the clocks can