1 files changed, 73 insertions, 0 deletions
diff --git a/drivers/soc/aspeed/aspeed-sbc.c b/drivers/soc/aspeed/aspeed-sbc.c
new file mode 100644
index 000000000000..be4497b418c4
--- /dev/null
+++ b/drivers/soc/aspeed/aspeed-sbc.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Copyright 2022 IBM Corp. */
+
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/debugfs.h>
+
+#define SEC_STATUS		0x14
+#define ABR_IMAGE_SOURCE	BIT(13)
+#define OTP_PROTECTED		BIT(8)
+#define LOW_SEC_KEY		BIT(7)
+#define SECURE_BOOT		BIT(6)
+#define UART_BOOT		BIT(5)
+
+struct sbe {
+	u8 abr_image;
+	u8 low_security_key;
+	u8 otp_protected;
+	u8 secure_boot;
+	u8 invert;
+	u8 uart_boot;
+};
+
+static struct sbe sbe;
+
+static int __init aspeed_sbc_init(void)
+{
+	struct device_node *np;
+	void __iomem *base;
+	struct dentry *sbc_dir;
+	u32 security_status;
+
+	/* AST2600 only */
+	np = of_find_compatible_node(NULL, NULL, "aspeed,ast2600-sbc");
+	if (!of_device_is_available(np))
+		return -ENODEV;
+
+	base = of_iomap(np, 0);
+	if (!base) {
+		of_node_put(np);
+		return -ENODEV;
+	}
+
+	security_status = readl(base + SEC_STATUS);
+
+	iounmap(base);
+	of_node_put(np);
+
+	sbe.abr_image = !!(security_status & ABR_IMAGE_SOURCE);
+	sbe.low_security_key = !!(security_status & LOW_SEC_KEY);
+	sbe.otp_protected = !!(security_status & OTP_PROTECTED);
+	sbe.secure_boot = !!(security_status & SECURE_BOOT);
+	/* Invert the bit, as 1 is boot from SPI/eMMC */
+	sbe.uart_boot =  !(security_status & UART_BOOT);
+
+	pr_info("AST2600 secure boot %s\n", sbe.secure_boot ? "enabled" : "disabled");
+
+	sbc_dir = debugfs_create_dir("sbc", arch_debugfs_dir);
+	if (IS_ERR(sbc_dir))
+		return PTR_ERR(sbc_dir);
+
+	debugfs_create_u8("abr_image", 0444, sbc_dir, &sbe.abr_image);
+	debugfs_create_u8("low_security_key", 0444, sbc_dir, &sbe.low_security_key);
+	debugfs_create_u8("otp_protected", 0444, sbc_dir, &sbe.otp_protected);
+	debugfs_create_u8("uart_boot", 0444, sbc_dir, &sbe.uart_boot);
+	debugfs_create_u8("secure_boot", 0444, sbc_dir, &sbe.secure_boot);
+
+	return 0;
+}
+
+subsys_initcall(aspeed_sbc_init);