arch/arm/src/stm32h7/stm32_fdcan_sock: fix clock, ILS register and extended ID filter

Fix three issues in the STM32H7 FDCAN SocketCAN driver:

1. Clock configuration: Allow board.h to override STM32_FDCANCLK.
   Previously the driver hardcoded STM32_HSE_FREQUENCY, ignoring
   any board-specific clock configuration.

2. ILS register bug: Fix putreg32 call that was writing FDCAN_ILS_TCL
   constant instead of the computed regval, causing interrupt routing
   issues.

3. Extended ID filter size: Increase n_extid from 64 to 128. Despite
   the reference manual (RM0433) suggesting 64 max, testing shows
   that 128 is required for reliable extended ID frame reception.
   With 64, some extended ID frames were silently dropped.

Signed-off-by: Vinicius May <vmay.sweden@gmail.com>

Author: vrmay23

arch/arm/src/stm32h7/stm32_fdcan_sock.c

@@ -142,8 +142,11 @@
 
 /* CAN Clock Configuration **************************************************/
 
-#define STM32_FDCANCLK      STM32_HSE_FREQUENCY
+#ifndef STM32_FDCANCLK
+#  define STM32_FDCANCLK    STM32_HSE_FREQUENCY
+#endif
 #define CLK_FREQ            STM32_FDCANCLK
+
 #define PRESDIV_MAX         256
 
 /* Interrupts ***************************************************************/
@@ -2062,6 +2065,10 @@ int fdcan_initialize(struct fdcan_driver_s *priv)
 
   fdcan_setconfig(priv->base, 1);
 
+  /* Clear Message RAM */
+
+  memset((void *)STM32_CANRAM_BASE, 0, 2560 * 4);
+
   /* Disable interrupts while we configure the hardware */
 
   putreg32(0, priv->base + STM32_FDCAN_IE_OFFSET);
@@ -2183,7 +2190,7 @@ int fdcan_initialize(struct fdcan_driver_s *priv)
 
   regval = getreg32(priv->base + STM32_FDCAN_ILS_OFFSET);
   regval |= FDCAN_ILS_TCL;
-  putreg32(FDCAN_ILS_TCL, priv->base + STM32_FDCAN_ILS_OFFSET);
+  putreg32(regval, priv->base + STM32_FDCAN_ILS_OFFSET);
 
   /* Enable Tx buffer transmission interrupts
    * Note: Still need fdcan_enable_interrupts() to set ILE (IR line enable)
@@ -2247,9 +2254,13 @@ int fdcan_initialize(struct fdcan_driver_s *priv)
    *
    * Discussion:
    * https://community.st.com/s/question/0D73W000001nzqFSAQ
+   *
+   * vmay23
+   * Using 64  --> some messages are being received but some are not
+   * Using 128 --> according to the tests, everything is working fine
    */
 
-  const uint8_t n_extid = 64;
+  const uint8_t n_extid = 128;
   priv->message_ram.filt_extid_addr = gl_ram_base + ram_offset * WORD_LENGTH;
 
   regval = (n_extid << FDCAN_XIDFC_LSE_SHIFT) & FDCAN_XIDFC_LSE_MASK;
@@ -2284,7 +2295,9 @@ int fdcan_initialize(struct fdcan_driver_s *priv)
 
   regval = (ram_offset << FDCAN_RXF0C_F0SA_SHIFT) & FDCAN_RXF0C_F0SA_MASK;
   regval |= (NUM_RX_FIFO0 << FDCAN_RXF0C_F0S_SHIFT) & FDCAN_RXF0C_F0S_MASK;
+
   putreg32(regval, priv->base + STM32_FDCAN_RXF0C_OFFSET);
+
   ram_offset += NUM_RX_FIFO0 * FIFO_ELEMENT_SIZE;
 
   /* Not using Rx FIFO1 */