gpio: rcar: add gen[123] fallback compatibility strings

Add fallback compatibility string for R-Car Gen 1, 2 and 3.

In the case of Renesas R-Car hardware we know that there are generations of
SoCs, f.e. Gen 1 and 2. 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,gpio-rcar as its name is more generic than its
implementation.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c
index 4a1536a050bc..1f0871553fd2 100644
--- a/drivers/gpio/gpio-rcar.c
+++ b/drivers/gpio/gpio-rcar.c
@@ -371,6 +371,16 @@ static const struct of_device_id gpio_rcar_of_table[] = {
 		/* Gen3 GPIO is identical to Gen2. */
 		.data = &gpio_rcar_info_gen2,
 	}, {
+		.compatible = "renesas,rcar-gen1-gpio",
+		.data = &gpio_rcar_info_gen1,
+	}, {
+		.compatible = "renesas,rcar-gen2-gpio",
+		.data = &gpio_rcar_info_gen2,
+	}, {
+		.compatible = "renesas,rcar-gen3-gpio",
+		/* Gen3 GPIO is identical to Gen2. */
+		.data = &gpio_rcar_info_gen2,
+	}, {
 		.compatible = "renesas,gpio-rcar",
 		.data = &gpio_rcar_info_gen1,
 	}, {