From f7f1b0bde0dcb69139ca90f9a6805b74463419e5 Mon Sep 17 00:00:00 2001
From: CarlWachter <carlwachter@web.de>
Date: Wed, 11 Sep 2024 16:28:58 +0200
Subject: [PATCH] feat(can): Split filtering for multiple can peripherals

---
 include/sta/devices/stm32/can.hpp |  5 ++++-
 src/devices/stm32/can.cpp         | 32 ++++++++++++++++++-------------
 2 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/include/sta/devices/stm32/can.hpp b/include/sta/devices/stm32/can.hpp
index eff37a4..4da17b3 100644
--- a/include/sta/devices/stm32/can.hpp
+++ b/include/sta/devices/stm32/can.hpp
@@ -46,8 +46,10 @@ namespace sta
     public:
         /**
          * @param handle    CAN handle
+         * 
+         * @param filter_start  Start index for filters (default: 0 for can1, 14 for can2)
          */
-        STM32CanController(CAN_HandleTypeDef * handle);
+        STM32CanController(CAN_HandleTypeDef * handle, uint32_t filter_start = 0);
 
         /**
          * @brief Enable RX pending interrupts.
@@ -97,6 +99,7 @@ namespace sta
     private:
         CAN_HandleTypeDef * handle_;                    /**< CAN handle */
         CAN_FilterTypeDef   filters_[MAX_FILTER_COUNT]; /**< Filter settings */
+        uint32_t            filter_start_;               /**< Start index for filters */
     };
 
 
diff --git a/src/devices/stm32/can.cpp b/src/devices/stm32/can.cpp
index ffd6a41..c396625 100644
--- a/src/devices/stm32/can.cpp
+++ b/src/devices/stm32/can.cpp
@@ -7,8 +7,8 @@
 
 namespace sta
 {
-    STM32CanController::STM32CanController(CAN_HandleTypeDef * handle)
-        : handle_{handle}
+    STM32CanController::STM32CanController(CAN_HandleTypeDef * handle, uint32_t filter_start)
+        : handle_{handle}, filter_start_{filter_start}
     {
         initFilters();
     }
@@ -141,7 +141,7 @@ namespace sta
 
     void STM32CanController::clearFilters()
     {
-        for (uint32_t i = 0; i < MAX_FILTER_COUNT; ++i)
+        for (uint32_t i = filter_start_; i < filter_start_ + MAX_FILTER_COUNT; ++i)
         {
             CAN_FilterTypeDef * config = &filters_[i];
 
@@ -157,17 +157,23 @@ namespace sta
 
     void STM32CanController::initFilters()
     {
-        for (uint32_t i = 0; i < MAX_FILTER_COUNT; ++i)
-        {
-            CAN_FilterTypeDef * config = &filters_[i];
-
-            config->FilterBank           = i;
-            config->FilterMode           = CAN_FILTERMODE_IDMASK;
-            config->FilterScale          = CAN_FILTERSCALE_32BIT;
-            config->FilterActivation     = CAN_FILTER_DISABLE;
-            config->SlaveStartFilterBank = MAX_FILTER_COUNT;
-            HAL_CAN_ConfigFilter(handle_, config);
+        CAN_FilterTypeDef * config = &filters_[filter_start_];
+        if (filter_start_ == 0){
+            config->FilterBank = 0;
+        }else{
+            // Split can peripheral bank for any STM F4 series supporting multiple CAN peripherals
+            config->FilterBank = filter_start_+1;
         }
+        
+        config->FilterMode           = CAN_FILTERMODE_IDMASK;
+        config->FilterScale          = CAN_FILTERSCALE_32BIT;
+        config->FilterActivation 	 = ENABLE;
+        config->FilterIdHigh 		 = 0x0000;
+        config->FilterIdLow 		 = 0x0000;
+        config->FilterMaskIdHigh 	 = 0x0000;
+        config->FilterMaskIdLow 	 = 0x0000;
+        config->SlaveStartFilterBank = filter_start_;
+        HAL_CAN_ConfigFilter(handle_, config);
     }
 
     CanPendingRxFifos STM32CanController::getPendingRxFifos(){