In the case of Renesas R-Car hardware we know that there are generations of
SoCs, e.g. Gen 2 and Gen 3. But beyond that its not clear what the
relationship between IP blocks might be. For example, I believe that
r8a7790 is older than r8a7791 but that doesn't imply that the latter is a
descendant of the former or vice versa.
We can, however, by examining the documentation and behaviour of the
hardware at run-time observe that the current driver implementation appears
to be compatible with the IP blocks on SoCs within a given generation.
For the above reasons and convenience when enabling new SoCs a
per-generation fallback compatibility string scheme being adopted for
drivers for Renesas SoCs.
Also deprecate renesas,i2c-rcar. It seems poorly named as it is only
compatible with R-Car Gen 1. It also appears unused in mainline.
Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
---
Documentation/devicetree/bindings/i2c/i2c-rcar.txt | 32 ++++++++++++++--------
1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt
index 239632a0d709..8c679b17c4c6 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt
@@ -1,17 +1,25 @@
I2C for R-Car platforms
Required properties:
-- compatible: Must be one of
- "renesas,i2c-rcar"
- "renesas,i2c-r8a7778"
- "renesas,i2c-r8a7779"
- "renesas,i2c-r8a7790"
- "renesas,i2c-r8a7791"
- "renesas,i2c-r8a7792"
- "renesas,i2c-r8a7793"
- "renesas,i2c-r8a7794"
- "renesas,i2c-r8a7795"
- "renesas,i2c-r8a7796"
+- compatible:
+ "renesas,i2c-r8a7778" if the device is a part of a R8A7778 SoC.
+ "renesas,i2c-r8a7779" if the device is a part of a R8A7797 SoC.
+ "renesas,i2c-r8a7790" if the device is a part of a R8A7790 SoC.
+ "renesas,i2c-r8a7791" if the device is a part of a R8A7791 SoC.
+ "renesas,i2c-r8a7792" if the device is a part of a R8A7792 SoC.
+ "renesas,i2c-r8a7793" if the device is a part of a R8A7793 SoC.
+ "renesas,i2c-r8a7794" if the device is a part of a R8A7794 SoC.
+ "renesas,i2c-r8a7795" if the device is a part of a R8A7795 SoC.
+ "renesas,i2c-r8a7796" if the device is a part of a R8A7796 SoC.
+ "renesas,i2c-rcar-gen1" for a generic R-Car Gen1 compatible device.
+ "renesas,i2c-rcar-gen2" for a generic R-Car Gen2 compatible device.
+ "renesas,i2c-rcar-gen3" for a generic R-Car Gen3 compatible device.
+ "renesas,i2c-rcar" (deprecated)
+
+ When compatible with the generic version, nodes must list the
+ SoC-specific version corresponding to the platform first followed
+ by the generic version.
+
- reg: physical base address of the controller and length of memory mapped
region.
- interrupts: interrupt specifier.
@@ -33,7 +41,7 @@ Examples :
i2c0: i2c@e6508000 {
#address-cells = <1>;
#size-cells = <0>;
- compatible = "renesas,i2c-r8a7791";
+ compatible = "renesas,i2c-r8a7791", "renesas,i2c-rcar-gen2";
reg = <0 0xe6508000 0 0x40>;
interrupts = <0 287 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&mstp9_clks R8A7791_CLK_I2C0>;
--
2.7.0.rc3.207.g0ac5344
--
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