clk: renesas: r8a7796: Add R8A77961 CPG/MSSR support

Add support for the R-Car M3-W+ (R8A77961) SoC to the Renesas Clock
Pulse Generator / Module Standby and Software Reset driver.

R-Car M3-W+ is very similar to R-Car M3-W (R8A77960), which allows for
both SoCs to share a driver. R-Car M3-W+ lacks a few modules, so their
clocks must be nullified.

Based on a patch in the BSP by Takeshi Kihara
<[e-mail]>.

Signed-off-by: Geert Uytterhoeven <[e-mail]>
Reviewed-by: Yoshihiro Shimoda <[e-mail]>
Tested-by: Yoshihiro Shimoda <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/clk/renesas/Kconfig

···
 	select CLK_R8A7794 if ARCH_R8A7794
 	select CLK_R8A7795 if ARCH_R8A7795
 	select CLK_R8A77960 if ARCH_R8A77960 || ARCH_R8A7796
+	select CLK_R8A77961 if ARCH_R8A77961
 	select CLK_R8A77965 if ARCH_R8A77965
 	select CLK_R8A77970 if ARCH_R8A77970
 	select CLK_R8A77980 if ARCH_R8A77980
···
 
 config CLK_R8A77960
 	bool "R-Car M3-W clock support" if COMPILE_TEST
+	select CLK_RCAR_GEN3_CPG
+
+config CLK_R8A77961
+	bool "R-Car M3-W+ clock support" if COMPILE_TEST
 	select CLK_RCAR_GEN3_CPG
 
 config CLK_R8A77965

drivers/clk/renesas/Makefile

···
 obj-$(CONFIG_CLK_R8A7794)		+= r8a7794-cpg-mssr.o
 obj-$(CONFIG_CLK_R8A7795)		+= r8a7795-cpg-mssr.o
 obj-$(CONFIG_CLK_R8A77960)		+= r8a7796-cpg-mssr.o
+obj-$(CONFIG_CLK_R8A77961)		+= r8a7796-cpg-mssr.o
 obj-$(CONFIG_CLK_R8A77965)		+= r8a77965-cpg-mssr.o
 obj-$(CONFIG_CLK_R8A77970)		+= r8a77970-cpg-mssr.o
 obj-$(CONFIG_CLK_R8A77980)		+= r8a77980-cpg-mssr.o

drivers/clk/renesas/r8a7796-cpg-mssr.c

···
 // SPDX-License-Identifier: GPL-2.0
 /*
- * r8a7796 Clock Pulse Generator / Module Standby and Software Reset
+ * r8a7796 (R-Car M3-W/W+) Clock Pulse Generator / Module Standby and Software
+ * Reset
  *
- * Copyright (C) 2016 Glider bvba
- * Copyright (C) 2018 Renesas Electronics Corp.
+ * Copyright (C) 2016-2019 Glider bvba
+ * Copyright (C) 2018-2019 Renesas Electronics Corp.
  *
  * Based on r8a7795-cpg-mssr.c
  *
···
 #include <linux/device.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/of.h>
 #include <linux/soc/renesas/rcar-rst.h>
 
 #include <dt-bindings/clock/r8a7796-cpg-mssr.h>
···
 	DEF_BASE("r",           R8A7796_CLK_R,     CLK_TYPE_GEN3_R, CLK_RINT),
 };
 
-static const struct mssr_mod_clk r8a7796_mod_clks[] __initconst = {
+static struct mssr_mod_clk r8a7796_mod_clks[] __initdata = {
 	DEF_MOD("fdp1-0",		 119,	R8A7796_CLK_S0D1),
 	DEF_MOD("scif5",		 202,	R8A7796_CLK_S3D4),
 	DEF_MOD("scif4",		 203,	R8A7796_CLK_S3D4),
···
 	{ 2,		192,	1,	192,	1,	32,	},
 };
 
+	/*
+	 * Fixups for R-Car M3-W+
+	 */
+
+static const unsigned int r8a77961_mod_nullify[] __initconst = {
+	MOD_CLK_ID(617),			/* FCPCI0  */
+};
+
 static int __init r8a7796_cpg_mssr_init(struct device *dev)
 {
 	const struct rcar_gen3_cpg_pll_config *cpg_pll_config;
···
 		dev_err(dev, "Prohibited setting (cpg_mode=0x%x)\n", cpg_mode);
 		return -EINVAL;
 	}
+
+	if (of_device_is_compatible(dev->of_node, "renesas,r8a77961-cpg-mssr"))
+		mssr_mod_nullify(r8a7796_mod_clks,
+				 ARRAY_SIZE(r8a7796_mod_clks),
+				 r8a77961_mod_nullify,
+				 ARRAY_SIZE(r8a77961_mod_nullify));
 
 	return rcar_gen3_cpg_init(cpg_pll_config, CLK_EXTALR, cpg_mode);
 }

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

···
 		.data = &r8a7796_cpg_mssr_info,
 	},
 #endif
+#ifdef CONFIG_CLK_R8A77961
+	{
+		.compatible = "renesas,r8a77961-cpg-mssr",
+		.data = &r8a7796_cpg_mssr_info,
+	},
+#endif
 #ifdef CONFIG_CLK_R8A77965
 	{
 		.compatible = "renesas,r8a77965-cpg-mssr",