Hi Simon,
On Thu, Dec 1, 2016 at 4:41 PM, Simon Horman <horms+renesas@xxxxxxxxxxxx> wrote:
> 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>
> ---
> Include accidently omitted i2c-rcar.c portion of patch
> ---
> Documentation/devicetree/bindings/i2c/i2c-rcar.txt | 32 ++++++++++++++--------
> drivers/i2c/busses/i2c-rcar.c | 5 +++-
> 2 files changed, 24 insertions(+), 13 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,rcar-gen1-i2c" etc.
> + "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";
"renesas,rcar-gen2-i2c"
> reg = <0 0xe6508000 0 0x40>;
> interrupts = <0 287 IRQ_TYPE_LEVEL_HIGH>;
> clocks = <&mstp9_clks R8A7791_CLK_I2C0>;
> diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
> index 726615e54f2a..622def6b43e2 100644
> --- a/drivers/i2c/busses/i2c-rcar.c
> +++ b/drivers/i2c/busses/i2c-rcar.c
> @@ -793,7 +793,6 @@ static const struct i2c_algorithm rcar_i2c_algo = {
> };
>
> static const struct of_device_id rcar_i2c_dt_ids[] = {
> - { .compatible = "renesas,i2c-rcar", .data = (void *)I2C_RCAR_GEN1 },
> { .compatible = "renesas,i2c-r8a7778", .data = (void *)I2C_RCAR_GEN1 },
> { .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 },
> { .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 },
> @@ -803,6 +802,10 @@ static const struct of_device_id rcar_i2c_dt_ids[] = {
> { .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 },
> { .compatible = "renesas,i2c-r8a7795", .data = (void *)I2C_RCAR_GEN3 },
> { .compatible = "renesas,i2c-r8a7796", .data = (void *)I2C_RCAR_GEN3 },
> + { .compatible = "renesas,i2c-rcar", .data = (void *)I2C_RCAR_GEN1 }, // Deprecated
> + { .compatible = "renesas,rcar-gen1-i2c", .data = (void *)I2C_RCAR_GEN1 },
> + { .compatible = "renesas,rcar-gen2-i2c", .data = (void *)I2C_RCAR_GEN2 },
> + { .compatible = "renesas,rcar-gen3-i2c", .data = (void *)I2C_RCAR_GEN3 },
The driver does it right ;-)
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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