From 047b8172ae6993cb6cacd07da94558411e81e11a Mon Sep 17 00:00:00 2001
From: Koen Zandberg <koen@bergzand.net>
Date: Wed, 30 Aug 2017 21:09:21 +0200
Subject: [PATCH] cc2420: Add RSSI dBm conversion

---
 drivers/cc2420/cc2420.c                   | 9 +++++++--
 drivers/cc2420/include/cc2420_registers.h | 8 ++++++++
 drivers/include/cc2420.h                  | 5 +++++
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/cc2420/cc2420.c b/drivers/cc2420/cc2420.c
index bb7ce3d5ce..2b4802772f 100644
--- a/drivers/cc2420/cc2420.c
+++ b/drivers/cc2420/cc2420.c
@@ -197,8 +197,8 @@ int cc2420_rx(cc2420_t *dev, uint8_t *buf, size_t max_len, void *info)
         DEBUG("cc2420: recv: reading %i byte of the packet\n", (int)len);
         cc2420_fifo_read(dev, buf, len);
 
-        uint8_t rssi;
-        cc2420_fifo_read(dev, &rssi, 1);
+        int8_t rssi;
+        cc2420_fifo_read(dev, (uint8_t*)&rssi, 1);
         DEBUG("cc2420: recv: RSSI is %i\n", (int)rssi);
 
         /* fetch and check if CRC_OK bit (MSB) is set */
@@ -208,6 +208,11 @@ int cc2420_rx(cc2420_t *dev, uint8_t *buf, size_t max_len, void *info)
             /* drop the corrupted frame from the RXFIFO */
             len = 0;
         }
+        if (info != NULL) {
+            netdev_ieee802154_rx_info_t *radio_info = info;
+            radio_info->rssi = CC2420_RSSI_OFFSET + rssi;
+            radio_info->lqi = crc_corr & CC2420_CRCCOR_COR_MASK;
+        }
 
         /* finally flush the FIFO */
         cc2420_strobe(dev, CC2420_STROBE_FLUSHRX);
diff --git a/drivers/cc2420/include/cc2420_registers.h b/drivers/cc2420/include/cc2420_registers.h
index 23cba2cee5..00725aa1fb 100644
--- a/drivers/cc2420/include/cc2420_registers.h
+++ b/drivers/cc2420/include/cc2420_registers.h
@@ -190,6 +190,14 @@ enum {
 #define CC2420_MDMCTRL0_PREAMBLE_3B (0x0002)
 /** @} */
 
+/**
+ * @brief  CRC/Correlation bit masks
+ * @{
+ */
+#define CC2420_CRCCOR_CRC_MASK      (0x80)
+#define CC2420_CRCCOR_COR_MASK      (0x7F)
+/** @} */
+
 /**
  * @name    Transmit control register bitfields
  * @{
diff --git a/drivers/include/cc2420.h b/drivers/include/cc2420.h
index cee30a128a..a2d6f77be4 100644
--- a/drivers/include/cc2420.h
+++ b/drivers/include/cc2420.h
@@ -61,6 +61,11 @@ extern "C" {
 #define CC2420_TXPOWER_DEFAULT  (IEEE802154_DEFAULT_TXPOWER)
 /** @} */
 
+/**
+ * @brief   RSSI offset
+ */
+#define CC2420_RSSI_OFFSET      (-45)
+
 /**
  * @brief   A couple of return values used in this driver
  */