From c9d989d136bd54ff8c8a527369e319f547ec6d70 Mon Sep 17 00:00:00 2001
From: bjackson312006 <blakejackson312006@gmail.com>
Date: Tue, 17 Feb 2026 09:55:09 -0500
Subject: [PATCH 1/2] Made it so DevAddr gets hardcoded in LAN8670_Init()

---
 general/include/lan8670.h |  6 ++----
 general/src/lan8670.c     | 11 ++++++++---
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/general/include/lan8670.h b/general/include/lan8670.h
index e8af66b5..91350654 100644
--- a/general/include/lan8670.h
+++ b/general/include/lan8670.h
@@ -47,12 +47,10 @@ typedef struct {
 /**
  * @brief Initializes a LAN8670 instance.
  * @param lan Pointer to the lan8670_t instance.
- * @param device_address The address of the LAN8670.
- * @param read Function pointer for reading data from the LAN8670.
- * @param write Function pointer for writing data to the LAN8670.
+ * @param DevAddr The device address of the LAN8670. This is a 5-bit value indicated by the PHYAD0-PHYAD4 pins and their pull-up/pull-down configuration.
  * @return Status.
  */
-int32_t LAN8670_Init(lan8670_t *lan); // Initializes a LAN8670 instance.
+int32_t LAN8670_Init(lan8670_t *lan, uint32_t DevAddr); // Initializes a LAN8670 instance.
 
 /**
  * @brief Performs a software reset of the LAN8670 Ethernet PHY.
diff --git a/general/src/lan8670.c b/general/src/lan8670.c
index 238e097c..530d187b 100644
--- a/general/src/lan8670.c
+++ b/general/src/lan8670.c
@@ -411,16 +411,21 @@ static int mmd_write_register_field(lan8670_t *lan, uint16_t mmd_addr, uint16_t
 
 /**** API FUNCTIONS ****/
 
-int32_t LAN8670_Init(lan8670_t *lan)
+int32_t LAN8670_Init(lan8670_t *lan, uint32_t DevAddr)
 {
-    // Set the device address to the SMIADR[4:0] field of the Strap Control 0 Register.
+    // Store the DevAddr
+    lan->DevAddr = DevAddr;
+    
+    // Double-check that DevAddr is the same as what's stored in the SMIADR[4:0] field of the Strap Control 0 Register.
     uint32_t buffer = 0;
 	int32_t status = read_register_field(lan, REG_STRAP_CTRL0, 0, 4, &buffer);
     if(status != 0) {
         debug(lan, "ERROR 0000: LAN8670_Init() failed to read Strap Control Register 0 (Status: %d)\n", status);
         return LAN8670_STATUS_READ_ERROR;
     }
-    lan->DevAddr = buffer;
+    if(lan->DevAddr != buffer) {
+        PRINTLN_WARNING("The hardcoded DevAddr value isn't the same as what's stored in SMIADR[4:0]. Something weird is probably going on (how did it even read the register in the first place)? (DevAddr=%d, SMIADR[4:0]=%d).", lan->DevAddr, buffer);
+    }
 
 	lan->debug = false; // Default to no debugging.
 

From 3b8ce48a11a45cd078c0015d85de4ff2454b253b Mon Sep 17 00:00:00 2001
From: bjackson312006 <blakejackson312006@gmail.com>
Date: Tue, 17 Feb 2026 11:07:20 -0500
Subject: [PATCH 2/2] Added LAN8670_Read_PHY_DevAddr()

---
 general/include/lan8670.h |  8 ++++++++
 general/src/lan8670.c     | 15 +++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/general/include/lan8670.h b/general/include/lan8670.h
index 91350654..427af195 100644
--- a/general/include/lan8670.h
+++ b/general/include/lan8670.h
@@ -226,4 +226,12 @@ int32_t LAN8670_Read_PHY_ID1(lan8670_t *lan, uint16_t *data);
  */
 int32_t LAN8670_Read_Model_Number(lan8670_t *lan, uint8_t *data);
 
+/**
+ * @brief Returns the PHY's device address according to the STRAP_CTRL0 register. This is a 5-bit value and should be consistent with how the device address is configured via the hardware pins.
+ * 
+ * @param lan Pointer to the lan8670_t instance.
+ * @param data Buffer for the value.
+ * @return Status.
+ */
+int32_t LAN8670_Read_PHY_DevAddr(lan8670_t *lan, uint8_t *data);
 // clang-format on
\ No newline at end of file
diff --git a/general/src/lan8670.c b/general/src/lan8670.c
index 530d187b..26c2ea6e 100644
--- a/general/src/lan8670.c
+++ b/general/src/lan8670.c
@@ -595,4 +595,19 @@ int32_t LAN8670_Read_Model_Number(lan8670_t *lan, uint8_t *data) {
     return LAN8670_STATUS_OK;
 }
 
+/* Returns the 5-bit PHY device address. */
+int32_t LAN8670_Read_PHY_DevAddr(lan8670_t *lan, uint8_t *data) {
+    // Read bits 4:0 of the STRAP_CTRL0 register (containing the DevAddr configured by the hardware pins).
+    uint32_t buffer = 0;
+	int32_t status = read_register_field(lan, REG_STRAP_CTRL0, 0, 4, &buffer);
+    if(status != 0) {
+        PRINTLN_ERROR("Failed to call read_register_field() to read the STRAP_CTRL0 register (Status: %d).", status);
+        return LAN8670_STATUS_READ_ERROR;
+    }
+
+    // Store the value
+    *data = (uint8_t)buffer;
+    return LAN8670_STATUS_OK;
+}
+
 // clang-format on
\ No newline at end of file