fix(spi): bound HAL v2 polling transfers

Author: cumin777

libraries/SPI/src/utility/spi_com.c

@@ -20,6 +20,17 @@
 extern "C" {
 #endif
 
+#if defined(USE_HALV2_DRIVER)
+/* HAL v2 polling APIs use HAL_GetTick() for their timeout. On the current
+ * Arduino C5 clock path that tick is not guaranteed to advance while polling,
+ * so use the Arduino microsecond clock to bound LL polling instead. */
+static bool spi_transfer_timed_out(uint32_t start_us)
+{
+  return (SPI_TRANSFER_TIMEOUT != HAL_MAX_DELAY)
+         && ((uint32_t)(micros() - start_us) >= (SPI_TRANSFER_TIMEOUT * 1000UL));
+}
+#endif
+
 /* Private Functions */
 /**
   * @brief  return clock freq of an SPI instance
@@ -564,13 +575,19 @@ spi_status_e spi_transfer(spi_t *obj, const uint8_t *tx_buffer, uint8_t *rx_buff
 {
   spi_status_e ret = SPI_OK;
   uint32_t tickstart, size = len;
+#if defined(USE_HALV2_DRIVER)
+  uint32_t start_us;
+#endif
   SPI_TypeDef *_SPI = obj->spi;
   uint8_t *tx_buf = (uint8_t *)tx_buffer;
 
   if (len == 0) {
     ret = SPI_ERROR;
   } else {
     tickstart = HAL_GetTick();
+#if defined(USE_HALV2_DRIVER)
+    start_us = micros();
+#endif
 
 #if defined(SPI_CR2_TSIZE)
     /* Start transfer */
@@ -581,14 +598,32 @@ spi_status_e spi_transfer(spi_t *obj, const uint8_t *tx_buffer, uint8_t *rx_buff
 
     while (size--) {
 #if defined(SPI_SR_TXP)
+#if defined(USE_HALV2_DRIVER)
+      while (!LL_SPI_IsActiveFlag_TXP(_SPI)) {
+        if (spi_transfer_timed_out(start_us)) {
+          ret = SPI_TIMEOUT;
+          goto spi_transfer_end;
+        }
+      }
+#else
       while (!LL_SPI_IsActiveFlag_TXP(_SPI));
+#endif
 #else
       while (!LL_SPI_IsActiveFlag_TXE(_SPI));
 #endif
       LL_SPI_TransmitData8(_SPI, tx_buf ? *tx_buf++ : 0XFF);
 
 #if defined(SPI_SR_RXP)
+#if defined(USE_HALV2_DRIVER)
+      while (!LL_SPI_IsActiveFlag_RXP(_SPI)) {
+        if (spi_transfer_timed_out(start_us)) {
+          ret = SPI_TIMEOUT;
+          goto spi_transfer_end;
+        }
+      }
+#else
       while (!LL_SPI_IsActiveFlag_RXP(_SPI));
+#endif
 #else
       while (!LL_SPI_IsActiveFlag_RXNE(_SPI));
 #endif
@@ -598,17 +633,24 @@ spi_status_e spi_transfer(spi_t *obj, const uint8_t *tx_buffer, uint8_t *rx_buff
         LL_SPI_ReceiveData8(_SPI);
       }
       if ((SPI_TRANSFER_TIMEOUT != HAL_MAX_DELAY) &&
+#if defined(USE_HALV2_DRIVER)
+          (spi_transfer_timed_out(start_us))) {
+#else
           (HAL_GetTick() - tickstart >= SPI_TRANSFER_TIMEOUT)) {
+#endif
         ret = SPI_TIMEOUT;
         break;
       }
     }
 
 #if defined(SPI_IFCR_EOTC)
+spi_transfer_end:
     // Add a delay before disabling SPI otherwise last-bit/last-clock may be truncated
     // See https://github.com/stm32duino/Arduino_Core_STM32/issues/1294
     // Computed delay is half SPI clock
-    delayMicroseconds(obj->disable_delay);
+    if (ret == SPI_OK) {
+      delayMicroseconds(obj->disable_delay);
+    }
 
     /* Close transfer */
     /* Clear flags */