[PATCH 1/3] soc: renesas: rz-sysc: Register auxiliary device for PWRRDY power sequencer

[Biju]

From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>

Some RZ SoCs (e.g. RZ/G3L) have a PWRRDY register that is controlled
through a power sequencer rather than directly by the SYSC driver.

Add a pwrrdy_pwrseq flag to struct rz_sysc_soc_id_init_data to mark
SoCs with this property, and set it for RZ/G3L. When set,
rz_sysc_probe() registers a "pwrseq-pwrrdy" auxiliary device so a
dedicated driver can handle the PWRRDY sequencing, with automatic
teardown via devm_add_action_or_reset().

Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
 drivers/soc/renesas/r9a08g046-sysc.c |  1 +
 drivers/soc/renesas/rz-sysc.c        | 40 ++++++++++++++++++++++++++++
 drivers/soc/renesas/rz-sysc.h        |  2 ++
 3 files changed, 43 insertions(+)

diff --git a/drivers/soc/renesas/r9a08g046-sysc.c b/drivers/soc/renesas/r9a08g046-sysc.c
index 90db9d383539..cd129c727461 100644
--- a/drivers/soc/renesas/r9a08g046-sysc.c
+++ b/drivers/soc/renesas/r9a08g046-sysc.c
@@ -76,6 +76,7 @@ static const struct rz_sysc_soc_id_init_data rzg3l_sysc_soc_id_init_data __initc
 	.devid_offset = 0xa04,
 	.revision_mask = GENMASK(31, 28),
 	.specific_id_mask = GENMASK(27, 0),
+	.pwrrdy_pwrseq = true,
 };
 
 const struct rz_sysc_init_data rzg3l_sysc_init_data __initconst = {
diff --git a/drivers/soc/renesas/rz-sysc.c b/drivers/soc/renesas/rz-sysc.c
index 161e8c38eea6..ea49ca51e740 100644
--- a/drivers/soc/renesas/rz-sysc.c
+++ b/drivers/soc/renesas/rz-sysc.c
@@ -5,6 +5,7 @@
  * Copyright (C) 2024 Renesas Electronics Corp.
  */
 
+#include <linux/auxiliary_bus.h>
 #include <linux/bitfield.h>
 #include <linux/cleanup.h>
 #include <linux/io.h>
@@ -84,6 +85,41 @@ static int rz_sysc_soc_init(struct rz_sysc *sysc, const struct of_device_id *mat
 	return 0;
 }
 
+static void rz_sysc_pwrrdy_pwrseq_unregister_adev(void *adev)
+{
+	auxiliary_device_delete(adev);
+	auxiliary_device_uninit(adev);
+}
+
+static int rz_sysc_pwrrdy_pwrseq_init(struct device *dev, const struct rz_sysc_init_data *data)
+{
+	const struct rz_sysc_soc_id_init_data *soc_data = data->soc_id_init_data;
+	struct auxiliary_device *adev;
+	int ret;
+
+	if (!soc_data->pwrrdy_pwrseq)
+		return 0;
+
+	adev = devm_kzalloc(dev, sizeof(*adev), GFP_KERNEL);
+	if (!adev)
+		return -ENOMEM;
+
+	adev->name = "pwrseq-pwrrdy";
+	adev->dev.parent = dev;
+
+	ret = auxiliary_device_init(adev);
+	if (ret)
+		return ret;
+
+	ret = auxiliary_device_add(adev);
+	if (ret) {
+		auxiliary_device_uninit(adev);
+		return ret;
+	}
+
+	return devm_add_action_or_reset(dev, rz_sysc_pwrrdy_pwrseq_unregister_adev, adev);
+}
+
 static const struct of_device_id rz_sysc_match[] = {
 #ifdef CONFIG_SYSC_R9A08G045
 	{ .compatible = "renesas,r9a08g045-sysc", .data = &rzg3s_sysc_init_data },
@@ -149,6 +185,10 @@ static int rz_sysc_probe(struct platform_device *pdev)
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);
 
+	ret = rz_sysc_pwrrdy_pwrseq_init(dev, match->data);
+	if (ret)
+		return ret;
+
 	return of_syscon_register_regmap(dev->of_node, regmap);
 }
 
diff --git a/drivers/soc/renesas/rz-sysc.h b/drivers/soc/renesas/rz-sysc.h
index 921ee0d26c47..e55f3258d703 100644
--- a/drivers/soc/renesas/rz-sysc.h
+++ b/drivers/soc/renesas/rz-sysc.h
@@ -20,6 +20,7 @@
  * @revision_mask: SYSC SoC ID revision mask
  * @specific_id_mask: SYSC SoC ID specific ID mask
  * @print_id: print SoC-specific extended device identification
+ * @pwrrdy_pwrseq: has pwrrdy register controlled through power sequencer
  */
 struct rz_sysc_soc_id_init_data {
 	const char * const family;
@@ -29,6 +30,7 @@ struct rz_sysc_soc_id_init_data {
 	u32 specific_id_mask;
 	void (*print_id)(struct device *dev, void __iomem *sysc_base,
 			 struct soc_device_attribute *soc_dev_attr);
+	bool pwrrdy_pwrseq;
 };
 
 /**
-- 
2.43.0