[PATCH v1 12/13] soc: starfive: Add socinfo driver for JHB100 SoC

[Changhuang Liang <changhuang.liang@starfivetech.com>]

Add socinfo driver for JHB100 SoC. Currently available for distinguishing
between the two reversions, A0 and A1.

Signed-off-by: Changhuang Liang <changhuang.liang@starfivetech.com>
---
 MAINTAINERS                                   |  6 ++
 drivers/soc/Kconfig                           |  1 +
 drivers/soc/Makefile                          |  1 +
 drivers/soc/starfive/Kconfig                  |  6 ++
 drivers/soc/starfive/Makefile                 |  2 +
 drivers/soc/starfive/socinfo/Kconfig          | 11 +++
 drivers/soc/starfive/socinfo/Makefile         |  2 +
 drivers/soc/starfive/socinfo/jhb100-socinfo.c | 90 +++++++++++++++++++
 8 files changed, 119 insertions(+)
 create mode 100644 drivers/soc/starfive/Kconfig
 create mode 100644 drivers/soc/starfive/Makefile
 create mode 100644 drivers/soc/starfive/socinfo/Kconfig
 create mode 100644 drivers/soc/starfive/socinfo/Makefile
 create mode 100644 drivers/soc/starfive/socinfo/jhb100-socinfo.c

diff --git a/MAINTAINERS b/MAINTAINERS
index eb5f6a383146..32bd94a0b94c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -25325,6 +25325,12 @@ S:	Maintained
 F:	drivers/reset/starfive/reset-starfive-jhb1*
 F:	include/dt-bindings/reset/starfive,jhb1*.h
 
+STARFIVE JHB100 SOCINFO DRIVER
+M:	Changhuang Liang <changhuang.liang@starfivetech.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/hwinfo/starfive,jhb100-socinfo.yaml
+F:	drivers/soc/starfive/socinfo/jhb100-socinfo.c
+
 STARFIVE JHB100 SYSCON
 M:	Changhuang Liang <changhuang.liang@starfivetech.com>
 S:	Maintained
diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index a2d65adffb80..b3b01fc38139 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -24,6 +24,7 @@ source "drivers/soc/renesas/Kconfig"
 source "drivers/soc/rockchip/Kconfig"
 source "drivers/soc/samsung/Kconfig"
 source "drivers/soc/sophgo/Kconfig"
+source "drivers/soc/starfive/Kconfig"
 source "drivers/soc/sunxi/Kconfig"
 source "drivers/soc/tegra/Kconfig"
 source "drivers/soc/ti/Kconfig"
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index c9e689080ceb..009f85ff891a 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -30,6 +30,7 @@ obj-y				+= renesas/
 obj-y				+= rockchip/
 obj-$(CONFIG_SOC_SAMSUNG)	+= samsung/
 obj-y				+= sophgo/
+obj-y				+= starfive/
 obj-y				+= sunxi/
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
 obj-y				+= ti/
diff --git a/drivers/soc/starfive/Kconfig b/drivers/soc/starfive/Kconfig
new file mode 100644
index 000000000000..04b020083d3e
--- /dev/null
+++ b/drivers/soc/starfive/Kconfig
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "StarFive SoC (System On Chip) specific Drivers"
+
+source "drivers/soc/starfive/socinfo/Kconfig"
+
+endmenu
diff --git a/drivers/soc/starfive/Makefile b/drivers/soc/starfive/Makefile
new file mode 100644
index 000000000000..ca1e609b8104
--- /dev/null
+++ b/drivers/soc/starfive/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-y += socinfo/
diff --git a/drivers/soc/starfive/socinfo/Kconfig b/drivers/soc/starfive/socinfo/Kconfig
new file mode 100644
index 000000000000..0a20382da5d3
--- /dev/null
+++ b/drivers/soc/starfive/socinfo/Kconfig
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config STARFIVE_JHB100_SOCINFO
+	tristate "StarFive JHB100 SoC Information"
+	depends on ARCH_STARFIVE || COMPILE_TEST
+	select SOC_BUS
+	default ARCH_STARFIVE
+	help
+	  Include support for the SoC bus socinfo for the StarFive JHB100 SoC
+	  platforms to provide information about the SoC family and variant
+	  to user space.
diff --git a/drivers/soc/starfive/socinfo/Makefile b/drivers/soc/starfive/socinfo/Makefile
new file mode 100644
index 000000000000..26c2bdf1de3b
--- /dev/null
+++ b/drivers/soc/starfive/socinfo/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_STARFIVE_JHB100_SOCINFO)	+= jhb100-socinfo.o
diff --git a/drivers/soc/starfive/socinfo/jhb100-socinfo.c b/drivers/soc/starfive/socinfo/jhb100-socinfo.c
new file mode 100644
index 000000000000..c2ad1c269314
--- /dev/null
+++ b/drivers/soc/starfive/socinfo/jhb100-socinfo.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 StarFive Technology Co., Ltd.
+ *
+ * Author: Changhuang Liang <changhuang.liang@starfivetech.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/sys_soc.h>
+
+#define JHB100_REV_ID_CHAR		GENMASK(3, 2)
+#define JHB100_REV_ID_NUM		GENMASK(1, 0)
+
+static void jhb100_soc_socdev_release(void *data)
+{
+	struct soc_device *soc_dev = data;
+
+	soc_device_unregister(soc_dev);
+}
+
+static int jhb100_soc_probe(struct platform_device *pdev)
+{
+	struct soc_device_attribute *soc_dev_attr;
+	struct soc_device *soc_dev;
+	void __iomem *base;
+	char rev_char;
+	u32 rev_id;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	soc_dev_attr = devm_kzalloc(&pdev->dev, sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		return -ENOMEM;
+
+	rev_id = readl(base);
+	rev_char = (char)FIELD_GET(JHB100_REV_ID_CHAR, rev_id) + 'A';
+	rev_id = (u32)FIELD_GET(JHB100_REV_ID_NUM, rev_id);
+
+	soc_dev_attr->revision = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%c%u",
+						rev_char, rev_id);
+	soc_dev_attr->family = "JH";
+	soc_dev_attr->soc_id = "JHB100";
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev))
+		return -ENODEV;
+
+	dev_info(&pdev->dev, "StarFive %s SoC rev(%s)\n", soc_dev_attr->soc_id,
+		 soc_dev_attr->revision);
+
+	return devm_add_action_or_reset(&pdev->dev, jhb100_soc_socdev_release,
+					soc_dev);
+}
+
+static const struct of_device_id jhb100_soc_of_match[] = {
+	{ .compatible = "starfive,jhb100-socinfo", },
+	{ }
+};
+
+static struct platform_driver jhb100_soc_driver = {
+	.probe = jhb100_soc_probe,
+	.driver = {
+		.name = "jhb100-socinfo",
+		.of_match_table = jhb100_soc_of_match,
+	},
+};
+
+static int __init jhb100_soc_init(void)
+{
+	return platform_driver_register(&jhb100_soc_driver);
+}
+
+static void __exit jhb100_soc_exit(void)
+{
+	platform_driver_unregister(&jhb100_soc_driver);
+}
+
+subsys_initcall(jhb100_soc_init);
+module_exit(jhb100_soc_exit);
+
+MODULE_AUTHOR("Changhuang Liang <changhuang.liang@starfivetech.com>");
+MODULE_DESCRIPTION("StarFive JHB100 SoC Information Driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1