From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Viacheslav Bocharov <adeep@lexina.in>
Date: Mon, 12 Jan 2026 15:26:33 +0300
Subject: arm: meson: add securemonitor getmax function

Add sm getmax [name] cli function to get size of AmLogic soc efuse

Signed-off-by: Viacheslav Bocharov <adeep@lexina.in>
---
 arch/arm/include/asm/arch-meson/sm.h |  9 ++++
 arch/arm/mach-meson/sm.c             | 18 +++++++
 cmd/meson/sm.c                       | 27 +++++++++-
 drivers/sm/meson-sm.c                |  1 +
 include/meson/sm.h                   |  1 +
 5 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/arch-meson/sm.h b/arch/arm/include/asm/arch-meson/sm.h
index 111111111111..222222222222 100644
--- a/arch/arm/include/asm/arch-meson/sm.h
+++ b/arch/arm/include/asm/arch-meson/sm.h
@@ -83,6 +83,15 @@ int meson_sm_get_serial(void *buffer, size_t size);
  */
 int meson_sm_get_chip_id(struct meson_sm_chip_id *chip_id);
 
+
+/**
+ * meson_sm_getmax - get max size of user efuse
+ * @buffer: pointer to buffer
+ * @size: buffer size
+ * @return: size of user efuse or -errno on failure
+ */
+ssize_t meson_sm_getmax(void *buffer, size_t size);
+
 enum {
 	REBOOT_REASON_COLD = 0,
 	REBOOT_REASON_NORMAL = 1,
diff --git a/arch/arm/mach-meson/sm.c b/arch/arm/mach-meson/sm.c
index 111111111111..222222222222 100644
--- a/arch/arm/mach-meson/sm.c
+++ b/arch/arm/mach-meson/sm.c
@@ -78,6 +78,24 @@ ssize_t meson_sm_write_efuse(uintptr_t offset, void *buffer, size_t size)
 	return err;
 }
 
+ssize_t meson_sm_getmax(void *buffer, size_t size)
+{
+	struct udevice *dev;
+	struct pt_regs regs = { 0 };
+	int err;
+
+	dev = meson_get_sm_device();
+	if (IS_ERR(dev))
+		return PTR_ERR(dev);
+
+	err = sm_call_read(dev, buffer, size,
+			   MESON_SMC_CMD_EFUSE_MAX, &regs);
+	if (err < 0)
+		pr_err("Failed to read max size of efuse memory (%d)\n", err);
+
+	return err;
+}
+
 /*
  * Helps to handle two flavors of cpu_id layouts:
  *
diff --git a/cmd/meson/sm.c b/cmd/meson/sm.c
index 111111111111..222222222222 100644
--- a/cmd/meson/sm.c
+++ b/cmd/meson/sm.c
@@ -152,12 +152,36 @@ free_buffer:
 	return ret;
 }
 
+static int do_efuse_getmax(struct cmd_tbl *cmdtp, int flag, int argc,
+			   char *const argv[])
+{
+	char efusesizeprint[32]; // this covers int64 (2^64), which is 20 digits long
+	char *destarg = NULL;
+	int efusesize;
+
+	if (argc > 1)
+		destarg = argv[1];
+
+	efusesize = meson_sm_getmax(NULL, 0); // TODO: check if this is correct
+	if (efusesize < 0)
+		return CMD_RET_FAILURE;
+
+	snprintf(efusesizeprint, sizeof(efusesizeprint), "%d", efusesize);
+	if (destarg)
+		env_set(destarg, efusesizeprint);
+	else
+		printf("%s\n", efusesizeprint);
+
+	return CMD_RET_SUCCESS;
+}
+
 static struct cmd_tbl cmd_sm_sub[] = {
 	U_BOOT_CMD_MKENT(serial, 2, 1, do_sm_serial, "", ""),
 	U_BOOT_CMD_MKENT(reboot_reason, 1, 1, do_sm_reboot_reason, "", ""),
 	U_BOOT_CMD_MKENT(efuseread, 4, 1, do_efuse_read, "", ""),
 	U_BOOT_CMD_MKENT(efusewrite, 4, 0, do_efuse_write, "", ""),
 	U_BOOT_CMD_MKENT(efusedump, 3, 1, do_efuse_dump, "", ""),
+	U_BOOT_CMD_MKENT(getmax, 2, 1, do_efuse_getmax, "", ""),
 };
 
 static int do_sm(struct cmd_tbl *cmdtp, int flag, int argc,
@@ -187,5 +211,6 @@ U_BOOT_CMD(
 	"sm reboot_reason [name] - get reboot reason and store to environment\n"
 	"sm efuseread <offset> <size> <address> - read efuse to memory address\n"
 	"sm efusewrite <offset> <size> <address> - write into efuse from memory address\n"
-	"sm efusedump <offset> <size> - dump efuse data range to console"
+	"sm efusedump <offset> <size> - dump efuse data range to console\n"
+	"sm getmax [name] - get max size of user accessible efuse and store to environment"
 );
diff --git a/drivers/sm/meson-sm.c b/drivers/sm/meson-sm.c
index 111111111111..222222222222 100644
--- a/drivers/sm/meson-sm.c
+++ b/drivers/sm/meson-sm.c
@@ -166,6 +166,7 @@ static const struct meson_sm_data meson_sm_gxbb_data = {
 	.cmd_get_shmem_out = 0x82000021,
 	.shmem_size = SZ_4K,
 	.cmd = {
+		SET_CMD(MESON_SMC_CMD_EFUSE_MAX,   0x82000033),
 		SET_CMD(MESON_SMC_CMD_EFUSE_READ,  0x82000030),
 		SET_CMD(MESON_SMC_CMD_EFUSE_WRITE, 0x82000031),
 		SET_CMD(MESON_SMC_CMD_CHIP_ID_GET, 0x82000044),
diff --git a/include/meson/sm.h b/include/meson/sm.h
index 111111111111..222222222222 100644
--- a/include/meson/sm.h
+++ b/include/meson/sm.h
@@ -9,6 +9,7 @@
 #define __MESON_SM_CMD_H__
 
 enum meson_smc_cmd {
+	MESON_SMC_CMD_EFUSE_MAX,   /* get max size of user efuse */
 	MESON_SMC_CMD_EFUSE_READ,  /* read efuse memory */
 	MESON_SMC_CMD_EFUSE_WRITE, /* write efuse memory */
 	MESON_SMC_CMD_CHIP_ID_GET, /* readh chip unique id */
-- 
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