[PATCH] ARM: amlogic: add sm efuse write support and cmd for read/write efuse

[Vyacheslav Bocharov]

This adds support for amlogic efuse write and provides two subcommands
of "sm" command: "efuseread" and "efusewrite" to read/write bytes between
memory and efuse.

Signed-off-by: Vyacheslav Bocharov <ad...@lexina.in>
---
 arch/arm/mach-meson/sm.c | 68 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 67 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-meson/sm.c b/arch/arm/mach-meson/sm.c
index 1a8f23cb1fa..fb437b94d14 100644
--- a/arch/arm/mach-meson/sm.c
+++ b/arch/arm/mach-meson/sm.c
@@ -68,6 +68,26 @@ ssize_t meson_sm_read_efuse(uintptr_t offset, void *buffer, 
size_t size)
        return regs.regs[0];
 }
 
+ssize_t meson_sm_write_efuse(uintptr_t offset, void *buffer, size_t size)
+{
+       struct pt_regs regs;
+
+       meson_init_shmem();
+
+        memcpy(shmem_input, buffer, size);
+
+       regs.regs[0] = FN_EFUSE_WRITE;
+       regs.regs[1] = offset;
+       regs.regs[2] = size;
+
+       smc_call(&regs);
+
+       if (regs.regs[0] == 0)
+               return -1;
+
+       return 0;
+}
+
 #define SM_CHIP_ID_LENGTH      119
 #define SM_CHIP_ID_OFFSET      4
 #define SM_CHIP_ID_SIZE                12
@@ -187,9 +207,53 @@ static int do_sm_reboot_reason(struct cmd_tbl *cmdtp, int 
flag, int argc,
        return CMD_RET_SUCCESS;
 }
 
+static int do_efuse_read(struct cmd_tbl *cmdtp, int flag, int argc,
+                       char *const argv[])
+{
+       ulong address, offset, size;
+       int ret;
+
+       if (argc < 4)
+               return CMD_RET_USAGE;
+
+        offset = simple_strtoul(argv[1], NULL, 0);
+        size = simple_strtoul(argv[2], NULL, 0);
+
+        address = simple_strtoul(argv[3], NULL, 0);
+
+       ret = meson_sm_read_efuse(offset, (void *)address, size);
+       if (ret)
+               return CMD_RET_FAILURE;
+
+       return CMD_RET_SUCCESS;
+}
+
+static int do_efuse_write(struct cmd_tbl *cmdtp, int flag, int argc,
+                       char *const argv[])
+{
+       ulong address, offset, size;
+       int ret;
+
+       if (argc < 4)
+               return CMD_RET_USAGE;
+
+        offset = simple_strtoul(argv[1], NULL, 0);
+        size = simple_strtoul(argv[2], NULL, 0);
+
+        address = simple_strtoul(argv[3], NULL, 0);
+
+       ret = meson_sm_write_efuse(offset, (void *)address, size);
+       if (ret)
+               return CMD_RET_FAILURE;
+
+       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, "", ""),
 };
 
 static int do_sm(struct cmd_tbl *cmdtp, int flag, int argc,
@@ -216,5 +280,7 @@ U_BOOT_CMD(
        sm, 5, 0, do_sm,
        "Secure Monitor Control",
        "serial <address> - read chip unique id to memory address\n"
-       "sm reboot_reason [name] - get reboot reason and store to to 
environment"
+       "sm reboot_reason [name] - get reboot reason and store to 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"
 );
-- 
2.30.2