From 50947fe0d667aa22702e230bcb2fe16c5ee8a2ed Mon Sep 17 00:00:00 2001
From: Sugar Zhang <sugar.zhang@rock-chips.com>
Date: Mon, 1 Sep 2025 11:56:06 +0800
Subject: [PATCH] soc: rockchip: cpuinfo: Add rockchip_set_spec_sn

Parse 'spec-sn' as rockchip_soc_id bit[7:0].

e.g.

cpuinfo {
	compatible = "rockchip,cpuinfo";
	nvmem-cells = <&otp_id>, <&cpu_version>, <&cpu_code>, <&specification_serial_number>;
	nvmem-cell-names = "id", "cpu-version", "cpu-code", "spec-sn";
};

* bit[7~0]: 0x1 ~ 0x1a --- A ~ Z

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Change-Id: Ic1d3d384343f4bde0e65c7826260d5dcc5149e80
---
 drivers/soc/rockchip/rockchip-cpuinfo.c | 41 +++++++++++++++++++++++++
 include/linux/rockchip/cpu.h            |  1 +
 2 files changed, 42 insertions(+)

diff --git a/drivers/soc/rockchip/rockchip-cpuinfo.c b/drivers/soc/rockchip/rockchip-cpuinfo.c
index 6e25271669a1..98b9898eaa15 100644
--- a/drivers/soc/rockchip/rockchip-cpuinfo.c
+++ b/drivers/soc/rockchip/rockchip-cpuinfo.c
@@ -65,6 +65,45 @@ static int rk3566_soc_init(struct device *dev)
 	return 0;
 }
 
+static int rockchip_set_spec_sn(struct device *dev)
+{
+	struct nvmem_cell *cell;
+	u8 *val;
+
+	cell = nvmem_cell_get(dev, "spec-sn1");
+	if (!IS_ERR(cell)) {
+		val = nvmem_cell_read(cell, NULL);
+		nvmem_cell_put(cell);
+		if (IS_ERR(val))
+			return PTR_ERR(val);
+
+		if (*val) {
+			rockchip_soc_id &= ~ROCKCHIP_SOC_SSN_MASK;
+			rockchip_soc_id |= *val;
+			kfree(val);
+
+			return 0;
+		}
+
+		kfree(val);
+	}
+
+	cell = nvmem_cell_get(dev, "spec-sn");
+	if (!IS_ERR(cell)) {
+		val = nvmem_cell_read(cell, NULL);
+		nvmem_cell_put(cell);
+		if (IS_ERR(val))
+			return PTR_ERR(val);
+
+		rockchip_soc_id &= ~ROCKCHIP_SOC_SSN_MASK;
+		rockchip_soc_id |= *val;
+
+		kfree(val);
+	}
+
+	return 0;
+}
+
 static int rockchip_cpuinfo_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -80,6 +119,8 @@ static int rockchip_cpuinfo_probe(struct platform_device *pdev)
 			goto skip_cpu_code;
 	}
 
+	rockchip_set_spec_sn(dev);
+
 	cell = nvmem_cell_get(dev, "cpu-code1");
 	if (!IS_ERR(cell)) {
 		efuse_buf = nvmem_cell_read(cell, &len);
diff --git a/include/linux/rockchip/cpu.h b/include/linux/rockchip/cpu.h
index 53f5cb758d39..45a2001bd814 100644
--- a/include/linux/rockchip/cpu.h
+++ b/include/linux/rockchip/cpu.h
@@ -248,6 +248,7 @@ static inline bool cpu_is_rk3567(void) { return false; }
 static inline bool cpu_is_rk3568(void) { return false; }
 #endif
 
+#define ROCKCHIP_SOC_SSN_MASK	0xff
 #define ROCKCHIP_SOC_MASK	(ROCKCHIP_CPU_MASK | 0xff)
 #define ROCKCHIP_SOC_PX30	(ROCKCHIP_CPU_PX30 | 0x00)
 #define ROCKCHIP_SOC_PX30S	(ROCKCHIP_CPU_PX30 | 0x01)