From 78857f123d05e6fb7894b69f693af62145969980 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@bht-berlin.de>
Date: Tue, 14 Feb 2023 11:14:03 +0100
Subject: [PATCH] socket_zep: simulate RSSI

---
 cpu/native/socket_zep/socket_zep.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/cpu/native/socket_zep/socket_zep.c b/cpu/native/socket_zep/socket_zep.c
index 280a541a91bf..75ea96bf2173 100644
--- a/cpu/native/socket_zep/socket_zep.c
+++ b/cpu/native/socket_zep/socket_zep.c
@@ -32,6 +32,7 @@
 
 #include "net/ieee802154/radio.h"
 #include "socket_zep.h"
+#include "random.h"
 
 #define ENABLE_DEBUG 0
 #include "debug.h"
@@ -47,6 +48,26 @@
 /* dummy packet to register with ZEP dispatcher */
 #define SOCKET_ZEP_V2_TYPE_HELLO   (255)
 
+/* simulate RSSI by calculating error function of LQI */
+static const uint8_t lqi_to_rssi[256] = {
+     74,  74,  74,  74,  74,  74,  74,  74,  74,  75,  75,  75,  75,  75,  75,  75,
+     75,  75,  75,  75,  75,  75,  75,  75,  75,  75,  75,  75,  75,  75,  75,  75,
+     75,  76,  76,  76,  76,  76,  76,  76,  76,  76,  76,  76,  76,  76,  76,  76,
+     77,  77,  77,  77,  77,  77,  77,  77,  77,  77,  77,  77,  78,  78,  78,  78,
+     78,  78,  78,  78,  78,  79,  79,  79,  79,  79,  79,  79,  79,  80,  80,  80,
+     80,  80,  80,  80,  81,  81,  81,  81,  81,  81,  82,  82,  82,  82,  82,  83,
+     83,  83,  83,  83,  83,  84,  84,  84,  84,  85,  85,  85,  85,  85,  86,  86,
+     86,  86,  87,  87,  87,  87,  88,  88,  88,  88,  89,  89,  89,  90,  90,  90,
+     90,  91,  91,  91,  92,  92,  92,  93,  93,  93,  94,  94,  94,  95,  95,  95,
+     96,  96,  96,  97,  97,  97,  98,  98,  98,  99,  99, 100, 100, 100, 101, 101,
+    102, 102, 102, 103, 103, 104, 104, 104, 105, 105, 106, 106, 107, 107, 107, 108,
+    108, 109, 109, 110, 110, 111, 111, 112, 112, 112, 113, 113, 114, 114, 115, 115,
+    116, 116, 117, 117, 118, 118, 119, 119, 120, 120, 121, 121, 122, 122, 123, 123,
+    124, 124, 125, 125, 126, 126, 127, 127, 128, 128, 129, 129, 130, 130, 131, 131,
+    132, 132, 133, 133, 134, 135, 135, 136, 136, 137, 137, 138, 138, 139, 139, 140,
+    140, 141, 141, 142, 142, 143, 143, 144, 144, 145, 145, 146, 146, 147, 147, 148,
+};
+
 static size_t _zep_hdr_fill_v2_data(socket_zep_t *dev, zep_v2_data_hdr_t *hdr,
                                     size_t payload_len)
 {
@@ -581,7 +602,8 @@ static int _read(ieee802154_dev_t *dev, void *buf, size_t max_size,
 
     if (info) {
         info->lqi = zep->lqi_val;
-        info->rssi = -IEEE802154_RADIO_RSSI_OFFSET;
+        info->rssi = lqi_to_rssi[zep->lqi_val]
+                   + ((random_uint32() & 0x3) - 2);
     }
 
     memcpy(buf, zep + 1, zep->length - 2);