dt-bindings: mediatek: Add binding for mt8183 IOMMU and SMI

This patch adds decriptions for mt8183 IOMMU and SMI.

mt8183 has only one M4U like mt8173 and is also MTK IOMMU gen2 which
uses ARM Short-Descriptor translation table format.

The mt8183 M4U-SMI HW diagram is as below:

                          EMI
                           |
                          M4U
                           |
                       ----------
                       |        |
                   gals0-rx   gals1-rx
                       |        |
                       |        |
                   gals0-tx   gals1-tx
                       |        |
                      ------------
                       SMI Common
                      ------------
                           |
  +-----+-----+--------+-----+-----+-------+-------+
  |     |     |        |     |     |       |       |
  |     |  gals-rx  gals-rx  |   gals-rx gals-rx gals-rx
  |     |     |        |     |     |       |       |
  |     |     |        |     |     |       |       |
  |     |  gals-tx  gals-tx  |   gals-tx gals-tx gals-tx
  |     |     |        |     |     |       |       |
larb0 larb1  IPU0    IPU1  larb4  larb5  larb6    CCU
disp  vdec   img     cam    venc   img    cam

All the connections are HW fixed, SW can NOT adjust it.

Compared with mt8173, we add a GALS(Global Async Local Sync) module
between SMI-common and M4U, and additional GALS between larb2/3/5/6
and SMI-common. GALS can help synchronize for the modules in different
clock frequency, it can be seen as a "asynchronous fifo".

GALS can only help transfer the command/data while it doesn't have
the configuring register, thus it has the special "smi" clock and it
doesn't have the "apb" clock. From the diagram above, we add "gals0"
and "gals1" clocks for smi-common and add a "gals" clock for smi-larb.

>From the diagram above, IPU0/IPU1(Image Processor Unit) and CCU(Camera
Control Unit) is connected with smi-common directly, we can take them
as "larb2", "larb3" and "larb7", and their register spaces are
different with the normal larb.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.txt

@@ -2,9 +2,10 @@ SMI (Smart Multimedia Interface) Common
 
 The hardware block diagram please check bindings/iommu/mediatek,iommu.txt
 
-Mediatek SMI have two generations of HW architecture, mt2712 and mt8173 use
-the second generation of SMI HW while mt2701 uses the first generation HW of
-SMI.
+Mediatek SMI have two generations of HW architecture, here is the list
+which generation the SoCs use:
+generation 1: mt2701 and mt7623.
+generation 2: mt2712, mt8173 and mt8183.
 
 There's slight differences between the two SMI, for generation 2, the
 register which control the iommu port is at each larb's register base. But
@@ -19,6 +20,7 @@ Required properties:
 	"mediatek,mt2712-smi-common"
 	"mediatek,mt7623-smi-common", "mediatek,mt2701-smi-common"
 	"mediatek,mt8173-smi-common"
+	"mediatek,mt8183-smi-common"
 - reg : the register and size of the SMI block.
 - power-domains : a phandle to the power domain of this local arbiter.
 - clocks : Must contain an entry for each entry in clock-names.
@@ -30,6 +32,10 @@ Required properties:
 	    They may be the same if both source clocks are the same.
   - "async" : asynchronous clock, it help transform the smi clock into the emi
 	      clock domain, this clock is only needed by generation 1 smi HW.
+  and these 2 option clocks for generation 2 smi HW:
+  - "gals0": the path0 clock of GALS(Global Async Local Sync).
+  - "gals1": the path1 clock of GALS(Global Async Local Sync).
+  Here is the list which has this GALS: mt8183.
 
 Example:
 	smi_common: smi@14022000 {

Documentation/devicetree/bindings/memory-controllers/mediatek,smi-larb.txt

@@ -8,6 +8,7 @@ Required properties:
 		"mediatek,mt2712-smi-larb"
 		"mediatek,mt7623-smi-larb", "mediatek,mt2701-smi-larb"
 		"mediatek,mt8173-smi-larb"
+		"mediatek,mt8183-smi-larb"
 - reg : the register and size of this local arbiter.
 - mediatek,smi : a phandle to the smi_common node.
 - power-domains : a phandle to the power domain of this local arbiter.
@@ -16,6 +17,9 @@ Required properties:
   - "apb" : Advanced Peripheral Bus clock, It's the clock for setting
 	    the register.
   - "smi" : It's the clock for transfer data and command.
+  and this optional clock name:
+  - "gals": the clock for GALS(Global Async Local Sync).
+  Here is the list which has this GALS: mt8183.
 
 Required property for mt2701, mt2712 and mt7623:
 - mediatek,larb-id :the hardware id of this larb.