[PATCH v4 i2c/for-next] i2c: rcar: Add per-Generation fallback bindings
From: Simon Horman <hidden>
Date: 2016-12-02 14:25:36
Also in:
linux-i2c, linux-renesas-soc
Subsystem:
i2c subsystem, i2c subsystem host drivers, open firmware and flattened device tree bindings, renesas r-car i2c drivers, the rest · Maintainers:
Andi Shyti, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Wolfram Sang, Linus Torvalds
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 it's 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 is 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. * Add some text to describe per-SoC bindings Signed-off-by: Simon Horman <redacted> --- v4 * Correct grammar in changelog v3 * Consistently use renesas,<family>-<module> for new compat strings * Drop RFC designation v2 * 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..50c378ccb8e7 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,rcar-gen1-i2c" for a generic R-Car Gen1 compatible device. + "renesas,rcar-gen2-i2c" for a generic R-Car Gen2 compatible device. + "renesas,rcar-gen3-i2c" 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,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 }, {}, }; MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids);
--
2.7.0.rc3.207.g0ac5344