Move save and restore operation to a dedicated command

Save and restore are required for any commands and not only for the
USER_DATA.
Two new commands are created for that and README is changed accordingly.
For these new commands BMT456 does not exepct call to sendbyte but a
write byte on the command with a dummy value.
A test is done on the BMR version to know how to execute the command.

Moreover for the restore two options are provided to reload the default
configuration or the last saved configuration.
No automatic save is done after a restore.

Author: tcollet

README.md

@@ -28,6 +28,36 @@ bmr --bus /dev/i2c-1 --addr 0x40 <command> [subcommand] [--pretty-off|P]
 * `--addr` 7-bit device address (default: `0x40`).
 * `--pretty-off|P` disable pretty output
 
+## save — save current configuration
+
+```bash
+bmr ... save
+```
+
+### What it does
+
+Save all modifications to be permanent for next power cycle or call to restart
+command.
+
+## restore — restore configuration
+
+```bash
+bmr ... restore [default]
+```
+
+### What it does
+
+Reload and apply factory default configuration if default is set, otherwise
+reload the last saved configuration i.e. similar to call to the restart command.
+
+### Use case
+
+Drop the current change:
+
+```bash
+bmr --bus /dev/i2c-1 --addr 0x40 restore
+```
+
 ## read — Telemetry & sensor data
 
 ```bash
@@ -202,22 +232,20 @@ margins/timing profiles.
 
 ```bash
 bmr ... user-data get
-bmr ... user-data set --ascii "Hello" [--store]
+bmr ... user-data set --ascii "Hello"
 ```
 
 ### What it does
 
 Accesses vendor `USER_DATA_00` (0xB0) area for storing small notes or process
-metadata (e.g., calibration token). With `--store`, the tool persists changes
-via `STORE_USER_ALL` or device-specific store, observing NVM latency. See App
-Note 302 for STORE/RESTORE semantics and timing.
+metadata (e.g., calibration token).
 
 ### Use case
 
 Stamp a unit with a calibration tag, manufacturing information:
 
 ```bash
-bmr ... user-data set --ascii "Cal=OK@2025-11-09" --store
+bmr ... user-data set --ascii "Cal=OK@2025-11-09"
 ```
 
 Wait ~5–10 ms before re-reading to allow NVM write to complete.
@@ -605,7 +633,7 @@ Set typical limits and verify live sensors:
 bmr --bus /dev/i2c-1 --addr 0x40 temp set --ot-fault 110 --ot-warn 100 --ut-warn -20 --ut-fault -40
 
 # Persist if desired (device NVM):
-bmr --bus /dev/i2c-1 --addr 0x40 user-data set --store
+bmr --bus /dev/i2c-1 --addr 0x40 save
 
 # Read back limits and live temps
 bmr --bus /dev/i2c-1 --addr 0x40 temp get all
@@ -663,7 +691,7 @@ bmr --bus /dev/i2c-1 --addr 0x40 set temp \
 **Persist to NVM** (optional, if you want the policy/limits after power cycle):
 
 ```bash
-bmr --bus /dev/i2c-1 --addr 0x40 user-data set --store
+bmr --bus /dev/i2c-1 --addr 0x40 save
 ```
 
 **Verify**:
@@ -694,7 +722,7 @@ bmr --bus /dev/i2c-1 --addr 0x40 set temp --ot-fault 20
 bmr --bus /dev/i2c-1 --addr 0x40 set temp --ut-fault 30
 
 # Persist to NVM if you want the policy to survive power cycles
-#bmr --bus /dev/i2c-1 --addr 0x40 user-data set --store
+#bmr --bus /dev/i2c-1 --addr 0x40 save
 ```
 
 The rail shall shutdown, wait 16s, retry once, then:
@@ -709,7 +737,7 @@ bmr --bus /dev/i2c-1 --addr 0x40 temp set \
   --ot-fault 110 --ot-warn 100 --ut-warn -20 --ut-fault -40
 
 # Persist to NVM if you want the policy to survive power cycles
-bmr --bus /dev/i2c-1 --addr 0x40 user-data set --store
+bmr --bus /dev/i2c-1 --addr 0x40 save
 ```
 
 ## rw — direct access to a byte / word register

src/main.c

@@ -9,6 +9,7 @@
 #include "mfr_ramp_data.h"
 #include "mfr_addr_offset.h"
 #include "mfr_status_data.h"
+#include "mfr_save_restore.h"
 #include "timing_cmd.h"
 #include "read_cmd.h"
 #include "onoff_cmd.h"
@@ -47,13 +48,15 @@ usage(const char *p) {
 "\n"
 "Commands:\n"
 "  read [vin|vout|iout|temp1|temp2|duty|freq|all]\n"
+"  save\n"
+"  restore [default]\n"
 "  status\n"
 "  snapshot [--cycle 0..19] [--decode]\n"
 "  mfr-multi-pin get|set [--mode MODE] [--pg pushpull|highz] [--pg-enable 0|1] [--sec-rc-pull 0|1]\n"
 "  id\n"
 "  fwdata\n"
 "  restart\n"
-"  user-data get|set [--hex XX..|--ascii STR] [--store|--restore]\n"
+"  user-data get|set [--hex XX..|--ascii STR]\n"
 "  timing get|set [--profile safe|sequenced|fast|prebias]\n"
 "  fault get [all|temp|vin|vout|tonmax|iout]\n"
 "  fault temp set [--ot-delay 16s|32s|2^n] [--ot-mode disable-retry] [--ot-retries cont]\n"
@@ -278,6 +281,16 @@ main(int argc, char *const *argv) {
     goto fini;
   }
 
+  if (!strcmp(cmd, "save")) {
+    rc = cmd_save(fd);
+    goto fini;
+  }
+
+  if (!strcmp(cmd, "restore")) {
+    rc = cmd_restore(fd, sub_argc, sub_argv);
+    goto fini;
+  }
+
   usage(argv[0]);
   rc = EXIT_FAILURE;
 

src/meson.build

@@ -14,6 +14,7 @@ sources = [
   'mfr_ramp_data.c',
   'mfr_status_data.c',
   'mfr_addr_offset.c',
+  'mfr_save_restore.c',
   'timing_cmd.c',
   'read_cmd.c',
   'status_cmd.c',

src/mfr_save_restore.c

@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: AGPL-3.0-or-later */
+
+#include "pmbus_io.h"
+#include <stdio.h>
+#include <string.h>
+
+int
+cmd_save(int fd) {
+  uint8_t b[64];
+
+  /*
+   * For BMR456 STORE and RESTORE is not based on send byte but on a write byte with a dummy value
+   * Product version is read to know how to execute the command
+   */
+  pmbus_rd_block(fd, MFR_MODEL, b, (int)sizeof b);
+
+  if (strncmp((char *)b, "BMR456", (size_t)6))
+    pmbus_send_byte(fd, PMBUS_STORE_USER_ALL);
+  else
+    pmbus_wr_byte(fd, PMBUS_STORE_USER_ALL, 0x01);
+
+  puts("OK");
+
+  return 0;
+}
+
+int
+cmd_restore(int fd, int argc, char *const *argv) {
+  uint8_t b[64];
+  bool isDefault = false;
+
+  if ((argc) && !strcmp(argv[0], "default"))
+    isDefault = true;
+
+
+  /*
+   * For BMR456 STORE and RESTORE is not based on send byte but on a write byte with a dummy value
+   * Product version is read to know how to execute the command
+   */
+  pmbus_rd_block(fd, MFR_MODEL, b, (int)sizeof b);
+
+  if (isDefault) {
+    if (strncmp((char *)b, "BMR456", (size_t)6))
+      pmbus_send_byte(fd, PMBUS_RESTORE_DEFAULT_ALL);
+    else
+      pmbus_wr_byte(fd, PMBUS_RESTORE_DEFAULT_ALL, 0x01);
+  } else {
+    if (strncmp((char *)b, "BMR456", (size_t)6))
+      pmbus_send_byte(fd, PMBUS_RESTORE_USER_ALL);
+    else
+      pmbus_wr_byte(fd, PMBUS_RESTORE_USER_ALL, 0x01);
+  }
+
+  puts("OK");
+
+  return 0;
+}

src/mfr_save_restore.h

@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: AGPL-3.0-or-later */
+#pragma once
+
+int cmd_save(int fd);
+int cmd_restore(int fd, int argc, char *const *argv);

src/mfr_user_data.c

@@ -11,23 +11,24 @@
 
 int
 cmd_user_data(int fd, int argc, char *const *argv, int pretty) {
+  uint8_t b[64];
+
   if (argc < 1) {
     fprintf(stderr, "user-data get|set ...\n");
     return 2;
   }
 
   if (!strcmp(argv[0], "get")) {
-    uint8_t buf[64];
-    int n = pmbus_rd_block(fd, MFR_USER_DATA_00, buf, sizeof buf);
+    int n = pmbus_rd_block(fd, MFR_USER_DATA_00, b, sizeof b);
     if (n < 0) {
       perror("USER_DATA_00");
       return 1;
     }
 
     json_t *o = json_object();
     json_object_set_new(o, "len", json_integer(n));
-    json_object_set_new(o, "ascii", json_stringn((char *) buf, n));
-    json_add_hex_ascii(o, "hex", buf, (size_t)n);
+    json_object_set_new(o, "ascii", json_stringn((char *) b, n));
+    json_add_hex_ascii(o, "hex", b, (size_t)n);
 
     json_print_or_pretty(o, pretty);
 
@@ -36,20 +37,14 @@ cmd_user_data(int fd, int argc, char *const *argv, int pretty) {
 
   if (!strcmp(argv[0], "set")) {
     const char *hex = NULL, *ascii = NULL;
-    bool store = false, restore = false;
 
     for (int i = 1; i < argc; i++) {
       if (!strcmp(argv[i], "--hex") && i + 1 < argc)
         hex = argv[++i];
       else if (!strcmp(argv[i], "--ascii") && i + 1 < argc)
         ascii = argv[++i];
-      else if (!strcmp(argv[i], "--store"))
-        store = true;
-      else if (!strcmp(argv[i], "--restore"))
-        restore = true;
     }
 
-    uint8_t b[64];
     int n = 0;
 
     if (hex) {
@@ -85,13 +80,6 @@ cmd_user_data(int fd, int argc, char *const *argv, int pretty) {
       return 1;
     }
 
-    if (store)
-      pmbus_send_byte(fd, PMBUS_STORE_USER_ALL);
-    if (restore)
-      pmbus_send_byte(fd, PMBUS_RESTORE_USER_ALL);
-
-    puts("OK");
-
     return 0;
   }