From 2848a74f62a242955bc0dca92f22dc790b5d5df5 Mon Sep 17 00:00:00 2001
From: Ilya Zhuravlev <whatever@xyz.is>
Date: Thu, 1 Jul 2021 15:10:05 -0400
Subject: [PATCH] qmk_settings: retrieve supported settings

---
 quantum/qmk_settings.c | 20 ++++++++++++++++++++
 quantum/qmk_settings.h |  1 +
 quantum/vial.c         |  2 ++
 3 files changed, 23 insertions(+)

diff --git a/quantum/qmk_settings.c b/quantum/qmk_settings.c
index 50c4e39395..1524fd048d 100644
--- a/quantum/qmk_settings.c
+++ b/quantum/qmk_settings.c
@@ -64,6 +64,26 @@ void qmk_settings_reset(void) {
     save_settings();
 }
 
+void qmk_settings_query(uint16_t qsid_gt, void *buffer, size_t sz) {
+    /* set all FFs, so caller can identify when all settings are retrieved by looking for an 0xFFFF entry */
+    memset(buffer, 0xFF, sz);
+
+    size_t buffer_offset = 0;
+    for (size_t i = 0; i < sizeof(protos)/sizeof(*protos); ++i) {
+        uint16_t qsid;
+
+        /* if output buffer has no space left, bail out */
+        if (buffer_offset + sizeof(qsid) > sz)
+            break;
+
+        qsid = pgm_read_word(&protos[i].qsid);
+        if (qsid > qsid_gt) {
+            memcpy((char*)buffer + buffer_offset, &qsid, sizeof(qsid));
+            buffer_offset += sizeof(qsid);
+        }
+    }
+}
+
 int qmk_settings_get(uint16_t qsid, void *setting, size_t maxsz) {
     const qmk_settings_proto_t *proto = find_setting(qsid);
     if (!proto || pgm_read_word(&proto->sz) > maxsz)
diff --git a/quantum/qmk_settings.h b/quantum/qmk_settings.h
index 5aaed68d6b..5dff122793 100644
--- a/quantum/qmk_settings.h
+++ b/quantum/qmk_settings.h
@@ -58,6 +58,7 @@ typedef struct {
 
 void qmk_settings_init(void);
 void qmk_settings_reset(void);
+void qmk_settings_query(uint16_t qsid_gt, void *buffer, size_t sz);
 int qmk_settings_get(uint16_t qsid, void *setting, size_t maxsz);
 int qmk_settings_set(uint16_t qsid, const void *setting, size_t maxsz);
 
diff --git a/quantum/vial.c b/quantum/vial.c
index e5fa51c645..1edbe94e77 100644
--- a/quantum/vial.c
+++ b/quantum/vial.c
@@ -165,6 +165,8 @@ void vial_handle_cmd(uint8_t *msg, uint8_t length) {
             break;
         }
         case vial_qmk_settings_query: {
+            uint16_t qsid_greater_than = msg[2] | (msg[3] << 8);
+            qmk_settings_query(qsid_greater_than, msg, length);
             break;
         }
         case vial_qmk_settings_get: {