rockchip: rk3576: Implement checkboard() to print SoC variant

Implement checkboard() to print current SoC model used by a board when
U-Boot proper is running.

  U-Boot 2025.04 (Apr 22 2025 - 20:43:17 +0000)

  Model: Generic RK3576
  SoC:   RK3576
  DRAM:  8 GiB

Information about the SoC model and variant is read from OTP.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

1 files changed, 48 insertions, 0 deletions

diff --git a/arch/arm/mach-rockchip/rk3576/rk3576.c b/arch/arm/mach-rockchip/rk3576/rk3576.c
index ba5c94b4b3d..2b1318f9532 100644
--- a/arch/arm/mach-rockchip/rk3576/rk3576.c
+++ b/arch/arm/mach-rockchip/rk3576/rk3576.c
@@ -3,6 +3,10 @@
  * Copyright (c) 2024 Rockchip Electronics Co., Ltd
  */
 
+#define LOG_CATEGORY LOGC_ARCH
+
+#include <dm.h>
+#include <misc.h>
 #include <asm/armv8/mmu.h>
 #include <asm/arch-rockchip/bootrom.h>
 #include <asm/arch-rockchip/hardware.h>
@@ -153,3 +157,47 @@ int arch_cpu_init(void)
 
 	return 0;
 }
+
+#define RK3576_OTP_CPU_CODE_OFFSET		0x02
+#define RK3576_OTP_SPECIFICATION_OFFSET		0x08
+
+int checkboard(void)
+{
+	u8 cpu_code[2], specification;
+	struct udevice *dev;
+	char suffix[2];
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_ROCKCHIP_OTP) || !CONFIG_IS_ENABLED(MISC))
+		return 0;
+
+	ret = uclass_get_device_by_driver(UCLASS_MISC,
+					  DM_DRIVER_GET(rockchip_otp), &dev);
+	if (ret) {
+		log_debug("Could not find otp device, ret=%d\n", ret);
+		return 0;
+	}
+
+	/* cpu-code: SoC model, e.g. 0x35 0x76 */
+	ret = misc_read(dev, RK3576_OTP_CPU_CODE_OFFSET, cpu_code, 2);
+	if (ret < 0) {
+		log_debug("Could not read cpu-code, ret=%d\n", ret);
+		return 0;
+	}
+
+	/* specification: SoC variant, e.g. 0xA for RK3576J */
+	ret = misc_read(dev, RK3576_OTP_SPECIFICATION_OFFSET, &specification, 1);
+	if (ret < 0) {
+		log_debug("Could not read specification, ret=%d\n", ret);
+		return 0;
+	}
+	specification &= 0x1f;
+
+	/* for RK3576J i.e. '@' + 0xA = 'J' */
+	suffix[0] = specification > 1 ? '@' + specification : '\0';
+	suffix[1] = '\0';
+
+	printf("SoC:   RK%02x%02x%s\n", cpu_code[0], cpu_code[1], suffix);
+
+	return 0;
+}