clk: renesas: r8a7791/r8a7793: Add new CPG/MSSR driver

Add a new R-Car M2-W/N Clock Pulse Generator / Module Standby and
Software Reset driver, using the CPG/MSSR driver core.  This will enable
support for module resets, which are not supported by the existing
driver.

The old driver can still be used through a Kconfig option, to preserve
backward compatibility with old DTBs.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

drivers/clk/renesas/Kconfig

@@ -21,7 +21,7 @@ if CLK_RENESAS
 
 config CLK_RENESAS_LEGACY
 	bool "Legacy DT clock support"
-	depends on CLK_R8A7790
+	depends on CLK_R8A7790 || CLK_R8A7791
 	default y
 	help
 	  Enable backward compatibility with old device trees describing a
@@ -71,7 +71,8 @@ config CLK_R8A7790
 
 config CLK_R8A7791
 	bool
-	select CLK_RCAR_GEN2
+	select CLK_RCAR_GEN2 if CLK_RENESAS_LEGACY
+	select CLK_RCAR_GEN2_CPG
 	select CLK_RENESAS_DIV6
 
 config CLK_R8A7792

drivers/clk/renesas/Makefile

@@ -8,6 +8,7 @@ obj-$(CONFIG_CLK_R8A7745)		+= r8a7745-cpg-mssr.o
 obj-$(CONFIG_CLK_R8A7778)		+= clk-r8a7778.o
 obj-$(CONFIG_CLK_R8A7779)		+= clk-r8a7779.o
 obj-$(CONFIG_CLK_R8A7790)		+= r8a7790-cpg-mssr.o
+obj-$(CONFIG_CLK_R8A7791)		+= r8a7791-cpg-mssr.o
 obj-$(CONFIG_CLK_R8A7795)		+= r8a7795-cpg-mssr.o
 obj-$(CONFIG_CLK_R8A7796)		+= r8a7796-cpg-mssr.o
 obj-$(CONFIG_CLK_SH73A0)		+= clk-sh73a0.o

drivers/clk/renesas/renesas-cpg-mssr.c

@@ -645,6 +645,17 @@ static const struct of_device_id cpg_mssr_match[] = {
 		.data = &r8a7790_cpg_mssr_info,
 	},
 #endif
+#ifdef CONFIG_CLK_R8A7791
+	{
+		.compatible = "renesas,r8a7791-cpg-mssr",
+		.data = &r8a7791_cpg_mssr_info,
+	},
+	/* R-Car M2-N is (almost) identical to R-Car M2-W w.r.t. clocks. */
+	{
+		.compatible = "renesas,r8a7793-cpg-mssr",
+		.data = &r8a7791_cpg_mssr_info,
+	},
+#endif
 #ifdef CONFIG_CLK_R8A7795
 	{
 		.compatible = "renesas,r8a7795-cpg-mssr",

drivers/clk/renesas/renesas-cpg-mssr.h

@@ -133,6 +133,7 @@ struct cpg_mssr_info {
 extern const struct cpg_mssr_info r8a7743_cpg_mssr_info;
 extern const struct cpg_mssr_info r8a7745_cpg_mssr_info;
 extern const struct cpg_mssr_info r8a7790_cpg_mssr_info;
+extern const struct cpg_mssr_info r8a7791_cpg_mssr_info;
 extern const struct cpg_mssr_info r8a7795_cpg_mssr_info;
 extern const struct cpg_mssr_info r8a7796_cpg_mssr_info;