Improve furi_hal_serial API

targets/f18/api_symbols.csv

@@ -1,5 +1,5 @@
 entry,status,name,type,params
-Version,+,54.0,,
+Version,v,54.1,,
 Header,+,applications/services/bt/bt_service/bt.h,,
 Header,+,applications/services/cli/cli.h,,
 Header,+,applications/services/cli/cli_vcp.h,,
@@ -1273,6 +1273,7 @@ Function,+,furi_hal_sd_presence_init,void,
 Function,+,furi_hal_sd_read_blocks,FuriStatus,"uint32_t*, uint32_t, uint32_t"
 Function,+,furi_hal_sd_write_blocks,FuriStatus,"const uint32_t*, uint32_t, uint32_t"
 Function,+,furi_hal_serial_async_rx,uint8_t,FuriHalSerialHandle*
+Function,+,furi_hal_serial_async_rx_available,_Bool,FuriHalSerialHandle*
 Function,+,furi_hal_serial_async_rx_start,void,"FuriHalSerialHandle*, FuriHalSerialAsyncRxCallback, void*, _Bool"
 Function,+,furi_hal_serial_async_rx_stop,void,FuriHalSerialHandle*
 Function,+,furi_hal_serial_control_acquire,FuriHalSerialHandle*,FuriHalSerialId

targets/f7/api_symbols.csv

@@ -1,5 +1,5 @@
 entry,status,name,type,params
-Version,+,54.0,,
+Version,+,54.1,,
 Header,+,applications/drivers/subghz/cc1101_ext/cc1101_ext_interconnect.h,,
 Header,+,applications/services/bt/bt_service/bt.h,,
 Header,+,applications/services/cli/cli.h,,
@@ -1439,6 +1439,7 @@ Function,+,furi_hal_sd_presence_init,void,
 Function,+,furi_hal_sd_read_blocks,FuriStatus,"uint32_t*, uint32_t, uint32_t"
 Function,+,furi_hal_sd_write_blocks,FuriStatus,"const uint32_t*, uint32_t, uint32_t"
 Function,+,furi_hal_serial_async_rx,uint8_t,FuriHalSerialHandle*
+Function,+,furi_hal_serial_async_rx_available,_Bool,FuriHalSerialHandle*
 Function,+,furi_hal_serial_async_rx_start,void,"FuriHalSerialHandle*, FuriHalSerialAsyncRxCallback, void*, _Bool"
 Function,+,furi_hal_serial_async_rx_stop,void,FuriHalSerialHandle*
 Function,+,furi_hal_serial_control_acquire,FuriHalSerialHandle*,FuriHalSerialId

targets/f7/furi_hal/furi_hal_serial.c

@@ -782,6 +782,17 @@ void furi_hal_serial_async_rx_stop(FuriHalSerialHandle* handle) {
     furi_hal_serial_async_rx_configure(handle, NULL, NULL);
 }
 
+bool furi_hal_serial_async_rx_available(FuriHalSerialHandle* handle) {
+    furi_check(FURI_IS_IRQ_MODE());
+    furi_assert(handle->id < FuriHalSerialIdMax);
+
+    if(handle->id == FuriHalSerialIdUsart) {
+        return LL_USART_IsActiveFlag_RXNE_RXFNE(USART1);
+    } else {
+        return LL_LPUART_IsActiveFlag_RXNE_RXFNE(LPUART1);
+    }
+}
+
 uint8_t furi_hal_serial_async_rx(FuriHalSerialHandle* handle) {
     furi_check(FURI_IS_IRQ_MODE());
     furi_assert(handle->id < FuriHalSerialIdMax);

targets/f7/furi_hal/furi_hal_serial.h

@@ -130,6 +130,16 @@ void furi_hal_serial_async_rx_start(
  */
 void furi_hal_serial_async_rx_stop(FuriHalSerialHandle* handle);
 
+/** Check if there is data available for reading
+ *
+ * @warning    This function must be called only from the callback
+ *             FuriHalSerialAsyncRxCallback
+ *
+ * @param      handle    Serial handle
+ * @return     true if data is available for reading, false otherwise
+ */
+bool furi_hal_serial_async_rx_available(FuriHalSerialHandle* handle);
+
 /** Get data Serial receive
  *
  * @warning    This function must be called only from the callback