[PATCH v6 1/5] soc: renesas: rz-sysc: Add syscon/regmap support

[John Madieu <john.madieu.xa@bp.renesas.com>]

The RZ/G3E system controller has various registers that control or report
some properties specific to individual IPs. The regmap is registered as a
syscon device to allow these IP drivers to access the registers through the
regmap API.

As other RZ SoCs might have custom read/write callbacks or max-offsets,
add register a custom regmap configuration.

Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
[claudiu.beznea:
 - s/rzg3e_sysc_regmap/rzv2h_sysc_regmap in RZ/V2H sysc
   file
 - do not check the match->data validity in rz_sysc_probe() as it is
   always valid
 - register the regmap if data->regmap_cfg is valid]
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes:

v1 -> v2: no changes
v2 -> v3: no changes
v3 -> v4: no changes
v4 -> v5: no changes
v6: Addressed the review comments received at [1];

[1] https://lore.kernel.org/all/20250330214945.185725-2-john.madieu.xa@bp.renesas.com/

 drivers/soc/renesas/Kconfig          |  1 +
 drivers/soc/renesas/r9a08g045-sysc.c | 10 ++++++++++
 drivers/soc/renesas/r9a09g047-sys.c  | 10 ++++++++++
 drivers/soc/renesas/r9a09g057-sys.c  | 10 ++++++++++
 drivers/soc/renesas/rz-sysc.c        | 17 ++++++++++++++++-
 drivers/soc/renesas/rz-sysc.h        |  3 +++
 6 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/renesas/Kconfig b/drivers/soc/renesas/Kconfig
index fbc3b69d21a7..f3b7546092d6 100644
--- a/drivers/soc/renesas/Kconfig
+++ b/drivers/soc/renesas/Kconfig
@@ -437,6 +437,7 @@ config RST_RCAR
 
 config SYSC_RZ
 	bool "System controller for RZ SoCs" if COMPILE_TEST
+	select MFD_SYSCON
 
 config SYSC_R9A08G045
 	bool "Renesas RZ/G3S System controller support" if COMPILE_TEST
diff --git a/drivers/soc/renesas/r9a08g045-sysc.c b/drivers/soc/renesas/r9a08g045-sysc.c
index f4db1431e036..0ef6df77e25f 100644
--- a/drivers/soc/renesas/r9a08g045-sysc.c
+++ b/drivers/soc/renesas/r9a08g045-sysc.c
@@ -18,6 +18,16 @@ static const struct rz_sysc_soc_id_init_data rzg3s_sysc_soc_id_init_data __initc
 	.specific_id_mask = GENMASK(27, 0),
 };
 
+static const struct regmap_config rzg3s_sysc_regmap __initconst = {
+	.name = "rzg3s_sysc_regs",
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.fast_io = true,
+	.max_register = 0xe20,
+};
+
 const struct rz_sysc_init_data rzg3s_sysc_init_data __initconst = {
 	.soc_id_init_data = &rzg3s_sysc_soc_id_init_data,
+	.regmap_cfg = &rzg3s_sysc_regmap,
 };
diff --git a/drivers/soc/renesas/r9a09g047-sys.c b/drivers/soc/renesas/r9a09g047-sys.c
index cd2eb7782cfe..a3acf6dd2867 100644
--- a/drivers/soc/renesas/r9a09g047-sys.c
+++ b/drivers/soc/renesas/r9a09g047-sys.c
@@ -62,6 +62,16 @@ static const struct rz_sysc_soc_id_init_data rzg3e_sys_soc_id_init_data __initco
 	.print_id = rzg3e_sys_print_id,
 };
 
+static const struct regmap_config rzg3e_sysc_regmap __initconst = {
+	.name = "rzg3e_sysc_regs",
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.fast_io = true,
+	.max_register = 0x170c,
+};
+
 const struct rz_sysc_init_data rzg3e_sys_init_data = {
 	.soc_id_init_data = &rzg3e_sys_soc_id_init_data,
+	.regmap_cfg = &rzg3e_sysc_regmap,
 };
diff --git a/drivers/soc/renesas/r9a09g057-sys.c b/drivers/soc/renesas/r9a09g057-sys.c
index 4c21cc29edbc..c26821636dce 100644
--- a/drivers/soc/renesas/r9a09g057-sys.c
+++ b/drivers/soc/renesas/r9a09g057-sys.c
@@ -62,6 +62,16 @@ static const struct rz_sysc_soc_id_init_data rzv2h_sys_soc_id_init_data __initco
 	.print_id = rzv2h_sys_print_id,
 };
 
+static const struct regmap_config rzv2h_sysc_regmap __initconst = {
+	.name = "rzv2h_sysc_regs",
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.fast_io = true,
+	.max_register = 0x170c,
+};
+
 const struct rz_sysc_init_data rzv2h_sys_init_data = {
 	.soc_id_init_data = &rzv2h_sys_soc_id_init_data,
+	.regmap_cfg = &rzv2h_sysc_regmap,
 };
diff --git a/drivers/soc/renesas/rz-sysc.c b/drivers/soc/renesas/rz-sysc.c
index ffa65fb4dade..70556a2f55e6 100644
--- a/drivers/soc/renesas/rz-sysc.c
+++ b/drivers/soc/renesas/rz-sysc.c
@@ -6,8 +6,10 @@
  */
 
 #include <linux/io.h>
+#include <linux/mfd/syscon.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/sys_soc.h>
 
 #include "rz-sysc.h"
@@ -100,14 +102,19 @@ MODULE_DEVICE_TABLE(of, rz_sysc_match);
 
 static int rz_sysc_probe(struct platform_device *pdev)
 {
+	const struct rz_sysc_init_data *data;
 	const struct of_device_id *match;
 	struct device *dev = &pdev->dev;
+	struct regmap *regmap;
 	struct rz_sysc *sysc;
+	int ret;
 
 	match = of_match_node(rz_sysc_match, dev->of_node);
 	if (!match)
 		return -ENODEV;
 
+	data = match->data;
+
 	sysc = devm_kzalloc(dev, sizeof(*sysc), GFP_KERNEL);
 	if (!sysc)
 		return -ENOMEM;
@@ -117,7 +124,15 @@ static int rz_sysc_probe(struct platform_device *pdev)
 		return PTR_ERR(sysc->base);
 
 	sysc->dev = dev;
-	return rz_sysc_soc_init(sysc, match);
+	ret = rz_sysc_soc_init(sysc, match);
+	if (ret || !data->regmap_cfg)
+		return ret;
+
+	regmap = devm_regmap_init_mmio(dev, sysc->base, data->regmap_cfg);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	return of_syscon_register_regmap(dev->of_node, regmap);
 }
 
 static struct platform_driver rz_sysc_driver = {
diff --git a/drivers/soc/renesas/rz-sysc.h b/drivers/soc/renesas/rz-sysc.h
index 56bc047a1bff..447008140634 100644
--- a/drivers/soc/renesas/rz-sysc.h
+++ b/drivers/soc/renesas/rz-sysc.h
@@ -9,6 +9,7 @@
 #define __SOC_RENESAS_RZ_SYSC_H__
 
 #include <linux/device.h>
+#include <linux/regmap.h>
 #include <linux/sys_soc.h>
 #include <linux/types.h>
 
@@ -34,9 +35,11 @@ struct rz_sysc_soc_id_init_data {
 /**
  * struct rz_sysc_init_data - RZ SYSC initialization data
  * @soc_id_init_data: RZ SYSC SoC ID initialization data
+ * @regmap_cfg: SoC-specific regmap config
  */
 struct rz_sysc_init_data {
 	const struct rz_sysc_soc_id_init_data *soc_id_init_data;
+	const struct regmap_config *regmap_cfg;
 };
 
 extern const struct rz_sysc_init_data rzg3e_sys_init_data;
-- 
2.25.1