[FL-3734] UART framing mode selection (#4121)

* HAL: feat: uart framing
* JS: feat: uart framing
* fix formatting
* fix pvs warning
* HAL: flash impact reduction attempt 1
* HAL: flash impact reduction attempt 2
* fix compile error
* HAL: finalize flash impact reduction
* HAL: remove user-facing magic numbers

Co-authored-by: Aleksandr Kutuzov <alleteam@gmail.com>

applications/debug/uart_echo/uart_echo.c

@@ -16,6 +16,9 @@
 #define LINES_ON_SCREEN   6
 #define COLUMNS_ON_SCREEN 21
 #define DEFAULT_BAUD_RATE 230400
+#define DEFAULT_DATA_BITS FuriHalSerialDataBits8
+#define DEFAULT_PARITY    FuriHalSerialParityNone
+#define DEFAULT_STOP_BITS FuriHalSerialStopBits1
 
 typedef struct UartDumpModel UartDumpModel;
 
@@ -49,11 +52,12 @@ typedef enum {
     WorkerEventRxOverrunError = (1 << 4),
     WorkerEventRxFramingError = (1 << 5),
     WorkerEventRxNoiseError = (1 << 6),
+    WorkerEventRxParityError = (1 << 7),
 } WorkerEventFlags;
 
 #define WORKER_EVENTS_MASK                                                                 \
     (WorkerEventStop | WorkerEventRxData | WorkerEventRxIdle | WorkerEventRxOverrunError | \
-     WorkerEventRxFramingError | WorkerEventRxNoiseError)
+     WorkerEventRxFramingError | WorkerEventRxNoiseError | WorkerEventRxParityError)
 
 const NotificationSequence sequence_notification = {
     &message_display_backlight_on,
@@ -62,6 +66,13 @@ const NotificationSequence sequence_notification = {
     NULL,
 };
 
+const NotificationSequence sequence_error = {
+    &message_display_backlight_on,
+    &message_red_255,
+    &message_delay_10,
+    NULL,
+};
+
 static void uart_echo_view_draw_callback(Canvas* canvas, void* _model) {
     UartDumpModel* model = _model;
 
@@ -133,6 +144,9 @@ static void
     if(event & FuriHalSerialRxEventOverrunError) {
         flag |= WorkerEventRxOverrunError;
     }
+    if(event & FuriHalSerialRxEventParityError) {
+        flag |= WorkerEventRxParityError;
+    }
 
     furi_thread_flags_set(furi_thread_get_id(app->worker_thread), flag);
 }
@@ -227,13 +241,21 @@ static int32_t uart_echo_worker(void* context) {
             if(events & WorkerEventRxNoiseError) {
                 furi_hal_serial_tx(app->serial_handle, (uint8_t*)"\r\nDetect NE\r\n", 13);
             }
+            if(events & WorkerEventRxParityError) {
+                furi_hal_serial_tx(app->serial_handle, (uint8_t*)"\r\nDetect PE\r\n", 13);
+            }
+            notification_message(app->notification, &sequence_error);
         }
     }
 
     return 0;
 }
 
-static UartEchoApp* uart_echo_app_alloc(uint32_t baudrate) {
+static UartEchoApp* uart_echo_app_alloc(
+    uint32_t baudrate,
+    FuriHalSerialDataBits data_bits,
+    FuriHalSerialParity parity,
+    FuriHalSerialStopBits stop_bits) {
     UartEchoApp* app = malloc(sizeof(UartEchoApp));
 
     app->rx_stream = furi_stream_buffer_alloc(2048, 1);
@@ -275,6 +297,7 @@ static UartEchoApp* uart_echo_app_alloc(uint32_t baudrate) {
     app->serial_handle = furi_hal_serial_control_acquire(FuriHalSerialIdUsart);
     furi_check(app->serial_handle);
     furi_hal_serial_init(app->serial_handle, baudrate);
+    furi_hal_serial_configure_framing(app->serial_handle, data_bits, parity, stop_bits);
 
     furi_hal_serial_async_rx_start(app->serial_handle, uart_echo_on_irq_cb, app, true);
 
@@ -318,19 +341,76 @@ static void uart_echo_app_free(UartEchoApp* app) {
     free(app);
 }
 
+// silences "same-assignment" false positives in the arg parser below
+// -V::1048
+
 int32_t uart_echo_app(void* p) {
     uint32_t baudrate = DEFAULT_BAUD_RATE;
+    FuriHalSerialDataBits data_bits = DEFAULT_DATA_BITS;
+    FuriHalSerialParity parity = DEFAULT_PARITY;
+    FuriHalSerialStopBits stop_bits = DEFAULT_STOP_BITS;
+
     if(p) {
-        const char* baudrate_str = p;
-        if(strint_to_uint32(baudrate_str, NULL, &baudrate, 10) != StrintParseNoError) {
-            FURI_LOG_E(TAG, "Invalid baudrate: %s", baudrate_str);
-            baudrate = DEFAULT_BAUD_RATE;
+        // parse argument
+        char* parse_ptr = p;
+        bool parse_success = false;
+
+        do {
+            if(strint_to_uint32(parse_ptr, &parse_ptr, &baudrate, 10) != StrintParseNoError) break;
+
+            if(*(parse_ptr++) != '_') break;
+
+            uint16_t data_bits_int;
+            if(strint_to_uint16(parse_ptr, &parse_ptr, &data_bits_int, 10) != StrintParseNoError)
+                break;
+            if(data_bits_int == 6)
+                data_bits = FuriHalSerialDataBits6;
+            else if(data_bits_int == 7)
+                data_bits = FuriHalSerialDataBits7;
+            else if(data_bits_int == 8)
+                data_bits = FuriHalSerialDataBits8;
+            else if(data_bits_int == 9)
+                data_bits = FuriHalSerialDataBits9;
+            else
+                break;
+
+            char parity_char = *(parse_ptr++);
+            if(parity_char == 'N')
+                parity = FuriHalSerialParityNone;
+            else if(parity_char == 'E')
+                parity = FuriHalSerialParityEven;
+            else if(parity_char == 'O')
+                parity = FuriHalSerialParityOdd;
+            else
+                break;
+
+            uint16_t stop_bits_int;
+            if(strint_to_uint16(parse_ptr, &parse_ptr, &stop_bits_int, 10) != StrintParseNoError)
+                break;
+            if(stop_bits_int == 5)
+                stop_bits = FuriHalSerialStopBits0_5;
+            else if(stop_bits_int == 1)
+                stop_bits = FuriHalSerialStopBits1;
+            else if(stop_bits_int == 15)
+                stop_bits = FuriHalSerialStopBits1_5;
+            else if(stop_bits_int == 2)
+                stop_bits = FuriHalSerialStopBits2;
+            else
+                break;
+
+            parse_success = true;
+        } while(0);
+
+        if(!parse_success) {
+            FURI_LOG_I(
+                TAG,
+                "Couldn't parse baud rate and framing (%s). Applying defaults (%d_8N1)",
+                (const char*)p,
+                DEFAULT_BAUD_RATE);
         }
     }
 
-    FURI_LOG_I(TAG, "Using baudrate: %lu", baudrate);
-
-    UartEchoApp* app = uart_echo_app_alloc(baudrate);
+    UartEchoApp* app = uart_echo_app_alloc(baudrate, data_bits, parity, stop_bits);
     view_dispatcher_run(app->view_dispatcher);
     uart_echo_app_free(app);
     return 0;

applications/debug/unit_tests/resources/unit_tests/js/basic.js

@@ -12,4 +12,4 @@ tests.assert_eq(false, doesSdkSupport(["abobus", "other-nonexistent-feature"]));
 
 tests.assert_eq("flipperdevices", flipper.firmwareVendor);
 tests.assert_eq(0, flipper.jsSdkVersion[0]);
-tests.assert_eq(2, flipper.jsSdkVersion[1]);
+tests.assert_eq(3, flipper.jsSdkVersion[1]);

applications/system/js_app/examples/apps/Scripts/uart_echo_8e1.js

@@ -0,0 +1,15 @@
+// This script is like uart_echo, except it uses 8E1 framing (8 data bits, even
+// parity, 1 stop bit) as opposed to the default 8N1 (8 data bits, no parity,
+// 1 stop bit)
+
+let serial = require("serial");
+serial.setup("usart", 230400, { dataBits: "8", parity: "even", stopBits: "1" });
+
+while (1) {
+    let rx_data = serial.readBytes(1, 1000);
+    if (rx_data !== undefined) {
+        serial.write(rx_data);
+        let data_view = Uint8Array(rx_data);
+        print("0x" + data_view[0].toString(16));
+    }
+}

applications/system/js_app/js_modules.c

@@ -269,6 +269,7 @@ static const char* extra_features[] = {
     "baseline", // dummy "feature"
     "gpio-pwm",
     "gui-widget",
+    "serial-framing",
 };
 
 /**

applications/system/js_app/js_modules.h

@@ -11,7 +11,7 @@
 
 #define JS_SDK_VENDOR "flipperdevices"
 #define JS_SDK_MAJOR  0
-#define JS_SDK_MINOR  2
+#define JS_SDK_MINOR  3
 
 /**
  * @brief Returns the foreign pointer in `obj["_"]`
@@ -81,6 +81,11 @@ typedef enum {
  */
 #define JS_AT_LEAST >=
 
+typedef struct {
+    const char* name;
+    size_t value;
+} JsEnumMapping;
+
 #define JS_ENUM_MAP(var_name, ...)                      \
     static const JsEnumMapping var_name##_mapping[] = { \
         {NULL, sizeof(var_name)},                       \
@@ -90,8 +95,14 @@ typedef enum {
 
 typedef struct {
     const char* name;
-    size_t value;
-} JsEnumMapping;
+    size_t offset;
+} JsObjectMapping;
+
+#define JS_OBJ_MAP(var_name, ...)                         \
+    static const JsObjectMapping var_name##_mapping[] = { \
+        __VA_ARGS__,                                      \
+        {NULL, 0},                                        \
+    };
 
 typedef struct {
     void* out;
@@ -199,6 +210,54 @@ static inline void
         _js_validate_enum,          \
         var_name##_mapping})
 
+static inline bool _js_validate_object(struct mjs* mjs, mjs_val_t val, const void* extra) {
+    for(const JsObjectMapping* mapping = (JsObjectMapping*)extra; mapping->name; mapping++)
+        if(mjs_get(mjs, val, mapping->name, ~0) == MJS_UNDEFINED) return false;
+    return true;
+}
+static inline void
+    _js_convert_object(struct mjs* mjs, mjs_val_t* val, void* out, const void* extra) {
+    const JsObjectMapping* mapping = (JsObjectMapping*)extra;
+    for(; mapping->name; mapping++) {
+        mjs_val_t field_val = mjs_get(mjs, *val, mapping->name, ~0);
+        *(mjs_val_t*)((uint8_t*)out + mapping->offset) = field_val;
+    }
+}
+#define JS_ARG_OBJECT(var_name, name) \
+    ((_js_arg_decl){                  \
+        &var_name,                    \
+        mjs_is_object,                \
+        _js_convert_object,           \
+        name " object",               \
+        _js_validate_object,          \
+        var_name##_mapping})
+
+/**
+ * @brief Validates and converts a JS value with a declarative interface
+ * 
+ * Example: `int32_t my_value; JS_CONVERT_OR_RETURN(mjs, &mjs_val, JS_ARG_INT32(&my_value), "value source");`
+ * 
+ * @warning This macro executes `return;` by design in case of a validation failure
+ */
+#define JS_CONVERT_OR_RETURN(mjs, value, decl, source, ...)        \
+    if(decl.validator)                                             \
+        if(!decl.validator(*value))                                \
+            JS_ERROR_AND_RETURN(                                   \
+                mjs,                                               \
+                MJS_BAD_ARGS_ERROR,                                \
+                source ": expected %s",                            \
+                ##__VA_ARGS__,                                     \
+                decl.expected_type);                               \
+    if(decl.extended_validator)                                    \
+        if(!decl.extended_validator(mjs, *value, decl.extra_data)) \
+            JS_ERROR_AND_RETURN(                                   \
+                mjs,                                               \
+                MJS_BAD_ARGS_ERROR,                                \
+                source ": expected %s",                            \
+                ##__VA_ARGS__,                                     \
+                decl.expected_type);                               \
+    decl.converter(mjs, value, decl.out, decl.extra_data);
+
 //-V:JS_FETCH_ARGS_OR_RETURN:1008
 /**
  * @brief Fetches and validates the arguments passed to a JS function
@@ -222,24 +281,7 @@ static inline void
             mjs_nargs(mjs));                                                           \
     for(int _i = 0; _i < _js_arg_cnt; _i++) {                                          \
         _js_arg_vals[_i] = mjs_arg(mjs, _i);                                           \
-        if(_js_args[_i].validator)                                                               \
-            if(!_js_args[_i].validator(_js_arg_vals[_i]))                                        \
-                JS_ERROR_AND_RETURN(                                                             \
-                    mjs,                                                                         \
-                    MJS_BAD_ARGS_ERROR,                                                          \
-                    "argument %d: expected %s",                                                  \
-                    _i,                                                                          \
-                    _js_args[_i].expected_type);                                                 \
-        if(_js_args[_i].extended_validator)                                                      \
-            if(!_js_args[_i].extended_validator(mjs, _js_arg_vals[_i], _js_args[_i].extra_data)) \
-                JS_ERROR_AND_RETURN(                                                             \
-                    mjs,                                                                         \
-                    MJS_BAD_ARGS_ERROR,                                                          \
-                    "argument %d: expected %s",                                                  \
-                    _i,                                                                          \
-                    _js_args[_i].expected_type);                                                 \
-        _js_args[_i].converter(                                                                  \
-            mjs, &_js_arg_vals[_i], _js_args[_i].out, _js_args[_i].extra_data);                  \
+        JS_CONVERT_OR_RETURN(mjs, &_js_arg_vals[_i], _js_args[_i], "argument %d", _i); \
     }
 
 /**

applications/system/js_app/modules/js_serial.c

@@ -20,14 +20,6 @@ typedef struct {
     char* data;
 } PatternArrayItem;
 
-static const struct {
-    const char* name;
-    const FuriHalSerialId value;
-} serial_channels[] = {
-    {"usart", FuriHalSerialIdUsart},
-    {"lpuart", FuriHalSerialIdLpuart},
-};
-
 ARRAY_DEF(PatternArray, PatternArrayItem, M_POD_OPLIST);
 
 static void
@@ -43,9 +35,54 @@ static void
 }
 
 static void js_serial_setup(struct mjs* mjs) {
-    mjs_val_t obj_inst = mjs_get(mjs, mjs_get_this(mjs), INST_PROP_NAME, ~0);
-    JsSerialInst* serial = mjs_get_ptr(mjs, obj_inst);
-    furi_assert(serial);
+    FuriHalSerialId serial_id;
+    int32_t baudrate;
+    JS_ENUM_MAP(serial_id, {"lpuart", FuriHalSerialIdLpuart}, {"usart", FuriHalSerialIdUsart});
+    JS_FETCH_ARGS_OR_RETURN(
+        mjs, JS_AT_LEAST, JS_ARG_ENUM(serial_id, "SerialId"), JS_ARG_INT32(&baudrate));
+
+    FuriHalSerialDataBits data_bits = FuriHalSerialDataBits8;
+    FuriHalSerialParity parity = FuriHalSerialParityNone;
+    FuriHalSerialStopBits stop_bits = FuriHalSerialStopBits1;
+    if(mjs_nargs(mjs) > 2) {
+        struct framing {
+            mjs_val_t data_bits;
+            mjs_val_t parity;
+            mjs_val_t stop_bits;
+        } framing;
+        JS_OBJ_MAP(
+            framing,
+            {"dataBits", offsetof(struct framing, data_bits)},
+            {"parity", offsetof(struct framing, parity)},
+            {"stopBits", offsetof(struct framing, stop_bits)});
+        JS_ENUM_MAP(
+            data_bits,
+            {"6", FuriHalSerialDataBits6},
+            {"7", FuriHalSerialDataBits7},
+            {"8", FuriHalSerialDataBits8},
+            {"9", FuriHalSerialDataBits9});
+        JS_ENUM_MAP(
+            parity,
+            {"none", FuriHalSerialParityNone},
+            {"even", FuriHalSerialParityEven},
+            {"odd", FuriHalSerialParityOdd});
+        JS_ENUM_MAP(
+            stop_bits,
+            {"0.5", FuriHalSerialStopBits0_5},
+            {"1", FuriHalSerialStopBits1},
+            {"1.5", FuriHalSerialStopBits1_5},
+            {"2", FuriHalSerialStopBits2});
+        mjs_val_t framing_obj = mjs_arg(mjs, 2);
+        JS_CONVERT_OR_RETURN(mjs, &framing_obj, JS_ARG_OBJECT(framing, "Framing"), "argument 2");
+        JS_CONVERT_OR_RETURN(
+            mjs, &framing.data_bits, JS_ARG_ENUM(data_bits, "DataBits"), "argument 2: dataBits");
+        JS_CONVERT_OR_RETURN(
+            mjs, &framing.parity, JS_ARG_ENUM(parity, "Parity"), "argument 2: parity");
+        JS_CONVERT_OR_RETURN(
+            mjs, &framing.stop_bits, JS_ARG_ENUM(stop_bits, "StopBits"), "argument 2: stopBits");
+    }
+
+    JsSerialInst* serial = JS_GET_CONTEXT(mjs);
 
     if(serial->setup_done) {
         mjs_prepend_errorf(mjs, MJS_INTERNAL_ERROR, "Serial is already configured");
@@ -53,43 +90,6 @@ static void js_serial_setup(struct mjs* mjs) {
         return;
     }
 
-    bool args_correct = false;
-    FuriHalSerialId serial_id = FuriHalSerialIdMax;
-    uint32_t baudrate = 0;
-
-    do {
-        if(mjs_nargs(mjs) != 2) break;
-
-        mjs_val_t arg = mjs_arg(mjs, 0);
-        if(!mjs_is_string(arg)) break;
-
-        size_t str_len = 0;
-        const char* arg_str = mjs_get_string(mjs, &arg, &str_len);
-        for(size_t i = 0; i < COUNT_OF(serial_channels); i++) {
-            size_t name_len = strlen(serial_channels[i].name);
-            if(str_len != name_len) continue;
-            if(strncmp(arg_str, serial_channels[i].name, str_len) == 0) {
-                serial_id = serial_channels[i].value;
-                break;
-            }
-        }
-        if(serial_id == FuriHalSerialIdMax) {
-            break;
-        }
-
-        arg = mjs_arg(mjs, 1);
-        if(!mjs_is_number(arg)) break;
-        baudrate = mjs_get_int32(mjs, arg);
-
-        args_correct = true;
-    } while(0);
-
-    if(!args_correct) {
-        mjs_prepend_errorf(mjs, MJS_BAD_ARGS_ERROR, "");
-        mjs_return(mjs, MJS_UNDEFINED);
-        return;
-    }
-
     expansion_disable(furi_record_open(RECORD_EXPANSION));
     furi_record_close(RECORD_EXPANSION);
 
@@ -97,6 +97,7 @@ static void js_serial_setup(struct mjs* mjs) {
     if(serial->serial_handle) {
         serial->rx_stream = furi_stream_buffer_alloc(RX_BUF_LEN, 1);
         furi_hal_serial_init(serial->serial_handle, baudrate);
+        furi_hal_serial_configure_framing(serial->serial_handle, data_bits, parity, stop_bits);
         furi_hal_serial_async_rx_start(
             serial->serial_handle, js_serial_on_async_rx, serial, false);
         serial->setup_done = true;

applications/system/js_app/packages/create-fz-app/template/package.json

@@ -6,7 +6,7 @@
     "start": "npm run build && node node_modules/@flipperdevices/fz-sdk/sdk.js upload"
   },
   "devDependencies": {
-    "@flipperdevices/fz-sdk": "^0.1",
+    "@flipperdevices/fz-sdk": "^0.3",
     "typescript": "^5.6.3"
   }
 }

applications/system/js_app/packages/fz-sdk/global.d.ts

@@ -72,7 +72,7 @@
  * @brief Checks compatibility between the script and the JS SDK that the
  *        firmware provides
  * 
- * @note You're looking at JS SDK v0.1
+ * @note You're looking at JS SDK v0.3
  * 
  * @param expectedMajor JS SDK major version expected by the script
  * @param expectedMinor JS SDK minor version expected by the script
@@ -92,7 +92,7 @@ declare function sdkCompatibilityStatus(expectedMajor: number, expectedMinor: nu
  * @brief Checks compatibility between the script and the JS SDK that the
  *        firmware provides in a boolean fashion
  * 
- * @note You're looking at JS SDK v0.1
+ * @note You're looking at JS SDK v0.3
  * 
  * @param expectedMajor JS SDK major version expected by the script
  * @param expectedMinor JS SDK minor version expected by the script
@@ -105,7 +105,7 @@ declare function isSdkCompatible(expectedMajor: number, expectedMinor: number):
  * @brief Asks the user whether to continue executing the script if the versions
  *        are not compatible. Does nothing if they are.
  * 
- * @note You're looking at JS SDK v0.1
+ * @note You're looking at JS SDK v0.3
  * 
  * @param expectedMajor JS SDK major version expected by the script
  * @param expectedMinor JS SDK minor version expected by the script

applications/system/js_app/packages/fz-sdk/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@flipperdevices/fz-sdk",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "description": "Type declarations and documentation for native JS modules available on Flipper Zero",
   "keywords": [
     "flipper",

applications/system/js_app/packages/fz-sdk/serial/index.d.ts

@@ -4,16 +4,33 @@
  * @module
  */
 
+export interface Framing {
+    /**
+     * @note 6 data bits can only be selected when parity is enabled (even or
+     * odd)
+     * @note 9 data bits can only be selected when parity is disabled (none)
+     */
+    dataBits: "6" | "7" | "8" | "9";
+    parity: "none" | "even" | "odd";
+    /**
+     * @note LPUART only supports whole stop bit lengths (i.e. 1 and 2 but not
+     * 0.5 and 1.5)
+     */
+    stopBits: "0.5" | "1" | "1.5" | "2";
+}
+
 /**
  * @brief Initializes the serial port
  * 
  * Automatically disables Expansion module service to prevent interference.
  * 
- * @param port The port to initialize (`"lpuart"` or `"start"`)
- * @param baudRate 
+ * @param port The port to initialize (`"lpuart"` or `"usart"`)
+ * @param baudRate Baud rate
+ * @param framing See `Framing` type
  * @version Added in JS SDK 0.1
+ * @version Added `framing` parameter in JS SDK 0.3, extra feature `"serial-framing"`
  */
-export declare function setup(port: "lpuart" | "usart", baudRate: number): void;
+export declare function setup(port: "lpuart" | "usart", baudRate: number, framing?: Framing): void;
 
 /**
  * @brief Writes data to the serial port

targets/f18/api_symbols.csv

@@ -1,5 +1,5 @@
 entry,status,name,type,params
-Version,+,80.3,,
+Version,+,80.4,,
 Header,+,applications/services/bt/bt_service/bt.h,,
 Header,+,applications/services/bt/bt_service/bt_keys_storage.h,,
 Header,+,applications/services/cli/cli.h,,
@@ -1437,6 +1437,7 @@ 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_configure_framing,void,"FuriHalSerialHandle*, FuriHalSerialDataBits, FuriHalSerialParity, FuriHalSerialStopBits"
 Function,+,furi_hal_serial_control_acquire,FuriHalSerialHandle*,FuriHalSerialId
 Function,+,furi_hal_serial_control_deinit,void,
 Function,+,furi_hal_serial_control_init,void,

targets/f7/api_symbols.csv

@@ -1,5 +1,5 @@
 entry,status,name,type,params
-Version,+,80.3,,
+Version,+,80.4,,
 Header,+,applications/drivers/subghz/cc1101_ext/cc1101_ext_interconnect.h,,
 Header,+,applications/services/bt/bt_service/bt.h,,
 Header,+,applications/services/bt/bt_service/bt_keys_storage.h,,
@@ -1627,6 +1627,7 @@ 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_configure_framing,void,"FuriHalSerialHandle*, FuriHalSerialDataBits, FuriHalSerialParity, FuriHalSerialStopBits"
 Function,+,furi_hal_serial_control_acquire,FuriHalSerialHandle*,FuriHalSerialId
 Function,+,furi_hal_serial_control_deinit,void,
 Function,+,furi_hal_serial_control_init,void,

targets/f7/furi_hal/furi_hal_serial.c

@@ -120,7 +120,7 @@ static void furi_hal_serial_usart_irq_callback(void* context) {
     }
     if(USART1->ISR & USART_ISR_PE) {
         USART1->ICR = USART_ICR_PECF;
-        event |= FuriHalSerialRxEventFrameError;
+        event |= FuriHalSerialRxEventParityError;
     }
 
     if(furi_hal_serial[FuriHalSerialIdUsart].buffer_rx_ptr == NULL) {
@@ -321,7 +321,7 @@ static void furi_hal_serial_lpuart_irq_callback(void* context) {
     }
     if(LPUART1->ISR & USART_ISR_PE) {
         LPUART1->ICR = USART_ICR_PECF;
-        event |= FuriHalSerialRxEventFrameError;
+        event |= FuriHalSerialRxEventParityError;
     }
 
     if(furi_hal_serial[FuriHalSerialIdLpuart].buffer_rx_ptr == NULL) {
@@ -605,6 +605,92 @@ void furi_hal_serial_set_br(FuriHalSerialHandle* handle, uint32_t baud) {
     }
 }
 
+// Avoid duplicating look-up tables between USART and LPUART
+static_assert(LL_LPUART_DATAWIDTH_7B == LL_USART_DATAWIDTH_7B);
+static_assert(LL_LPUART_DATAWIDTH_8B == LL_USART_DATAWIDTH_8B);
+static_assert(LL_LPUART_DATAWIDTH_9B == LL_USART_DATAWIDTH_9B);
+static_assert(LL_LPUART_PARITY_NONE == LL_USART_PARITY_NONE);
+static_assert(LL_LPUART_PARITY_EVEN == LL_USART_PARITY_EVEN);
+static_assert(LL_LPUART_PARITY_ODD == LL_USART_PARITY_ODD);
+static_assert(LL_LPUART_STOPBITS_1 == LL_USART_STOPBITS_1);
+static_assert(LL_LPUART_STOPBITS_2 == LL_USART_STOPBITS_2);
+
+static const uint32_t serial_data_bits_lut[] = {
+    [FuriHalSerialDataBits7] = LL_USART_DATAWIDTH_7B,
+    [FuriHalSerialDataBits8] = LL_USART_DATAWIDTH_8B,
+    [FuriHalSerialDataBits9] = LL_USART_DATAWIDTH_9B,
+};
+
+static const uint32_t serial_parity_lut[] = {
+    [FuriHalSerialParityNone] = LL_USART_PARITY_NONE,
+    [FuriHalSerialParityEven] = LL_USART_PARITY_EVEN,
+    [FuriHalSerialParityOdd] = LL_USART_PARITY_ODD,
+};
+
+static const uint32_t serial_stop_bits_lut[] = {
+    [FuriHalSerialStopBits0_5] = LL_USART_STOPBITS_0_5,
+    [FuriHalSerialStopBits1] = LL_USART_STOPBITS_1,
+    [FuriHalSerialStopBits1_5] = LL_USART_STOPBITS_1_5,
+    [FuriHalSerialStopBits2] = LL_USART_STOPBITS_2,
+};
+
+static void furi_hal_serial_usart_configure_framing(
+    FuriHalSerialDataBits data_bits,
+    FuriHalSerialParity parity,
+    FuriHalSerialStopBits stop_bits) {
+    LL_USART_SetDataWidth(USART1, serial_data_bits_lut[data_bits]);
+    LL_USART_SetParity(USART1, serial_parity_lut[parity]);
+    LL_USART_SetStopBitsLength(USART1, serial_stop_bits_lut[stop_bits]);
+}
+
+static void furi_hal_serial_lpuart_configure_framing(
+    FuriHalSerialDataBits data_bits,
+    FuriHalSerialParity parity,
+    FuriHalSerialStopBits stop_bits) {
+    LL_LPUART_SetDataWidth(LPUART1, serial_data_bits_lut[data_bits]);
+    LL_LPUART_SetParity(LPUART1, serial_parity_lut[parity]);
+    // Unsupported non-whole stop bit numbers have been furi_check'ed away
+    LL_LPUART_SetStopBitsLength(LPUART1, serial_stop_bits_lut[stop_bits]);
+}
+
+void furi_hal_serial_configure_framing(
+    FuriHalSerialHandle* handle,
+    FuriHalSerialDataBits data_bits,
+    FuriHalSerialParity parity,
+    FuriHalSerialStopBits stop_bits) {
+    furi_check(handle);
+
+    // Unsupported combinations
+    if(data_bits == FuriHalSerialDataBits9) furi_check(parity == FuriHalSerialParityNone);
+    if(data_bits == FuriHalSerialDataBits6) furi_check(parity != FuriHalSerialParityNone);
+
+    // Extend data word to account for parity bit
+    if(parity != FuriHalSerialParityNone) data_bits++;
+
+    if(handle->id == FuriHalSerialIdUsart) {
+        if(LL_USART_IsEnabled(USART1)) {
+            // Wait for transfer complete flag
+            while(!LL_USART_IsActiveFlag_TC(USART1))
+                ;
+            LL_USART_Disable(USART1);
+            furi_hal_serial_usart_configure_framing(data_bits, parity, stop_bits);
+            LL_USART_Enable(USART1);
+        }
+    } else if(handle->id == FuriHalSerialIdLpuart) {
+        // Unsupported configurations
+        furi_check(stop_bits == FuriHalSerialStopBits1 || stop_bits == FuriHalSerialStopBits2);
+
+        if(LL_LPUART_IsEnabled(LPUART1)) {
+            // Wait for transfer complete flag
+            while(!LL_LPUART_IsActiveFlag_TC(LPUART1))
+                ;
+            LL_LPUART_Disable(LPUART1);
+            furi_hal_serial_lpuart_configure_framing(data_bits, parity, stop_bits);
+            LL_LPUART_Enable(LPUART1);
+        }
+    }
+}
+
 void furi_hal_serial_deinit(FuriHalSerialHandle* handle) {
     furi_check(handle);
     furi_hal_serial_async_rx_configure(handle, NULL, NULL);

targets/f7/furi_hal/furi_hal_serial.h

@@ -16,7 +16,9 @@ extern "C" {
 
 /** Initialize Serial
  *
- * Configures GPIO, configures and enables transceiver.
+ * Configures GPIO, configures and enables transceiver. Default framing settings
+ * are used: 8 data bits, no parity, 1 stop bit. Override them with
+ * `furi_hal_serial_configure_framing`.
  *
  * @param      handle  Serial handle
  * @param      baud    baud rate
@@ -64,6 +66,20 @@ bool furi_hal_serial_is_baud_rate_supported(FuriHalSerialHandle* handle, uint32_
  */
 void furi_hal_serial_set_br(FuriHalSerialHandle* handle, uint32_t baud);
 
+/**
+ * @brief Configures framing of a serial interface
+ * 
+ * @param      handle     Serial handle
+ * @param      data_bits  Data bits
+ * @param      parity     Parity
+ * @param      stop_bits  Stop bits
+ */
+void furi_hal_serial_configure_framing(
+    FuriHalSerialHandle* handle,
+    FuriHalSerialDataBits data_bits,
+    FuriHalSerialParity parity,
+    FuriHalSerialStopBits stop_bits);
+
 /** Transmits data in semi-blocking mode
  *
  * Fills transmission pipe with data, returns as soon as all bytes from buffer
@@ -93,6 +109,7 @@ typedef enum {
     FuriHalSerialRxEventFrameError = (1 << 2), /**< Framing Error: incorrect frame detected */
     FuriHalSerialRxEventNoiseError = (1 << 3), /**< Noise Error: noise on the line detected */
     FuriHalSerialRxEventOverrunError = (1 << 4), /**< Overrun Error: no space for received data */
+    FuriHalSerialRxEventParityError = (1 << 5), /**< Parity Error: incorrect parity bit received */
 } FuriHalSerialRxEvent;
 
 /** Receive callback
@@ -172,7 +189,7 @@ typedef void (*FuriHalSerialDmaRxCallback)(
     void* context);
 
 /**
- * @brief Enable an input/output directon
+ * @brief Enable an input/output direction
  *
  * Takes over the respective pin by reconfiguring it to
  * the appropriate alternative function.
@@ -185,7 +202,7 @@ void furi_hal_serial_enable_direction(
     FuriHalSerialDirection direction);
 
 /**
- * @brief Disable an input/output directon
+ * @brief Disable an input/output direction
  *
  * Releases the respective pin by reconfiguring it to
  * initial state, making possible its use for other purposes.

targets/f7/furi_hal/furi_hal_serial_types.h

@@ -19,4 +19,39 @@ typedef enum {
     FuriHalSerialDirectionMax,
 } FuriHalSerialDirection;
 
+/**
+ * @brief Actual data bits, i.e. not including start/stop and parity bits
+ * @note 6 data bits are only permitted when parity is enabled
+ * @note 9 data bits are only permitted when parity is disabled
+ */
+typedef enum {
+    FuriHalSerialDataBits6,
+    FuriHalSerialDataBits7,
+    FuriHalSerialDataBits8,
+    FuriHalSerialDataBits9,
+
+    FuriHalSerialDataBitsMax,
+} FuriHalSerialDataBits;
+
+typedef enum {
+    FuriHalSerialParityNone,
+    FuriHalSerialParityEven,
+    FuriHalSerialParityOdd,
+
+    FuriHalSerialParityMax,
+} FuriHalSerialParity;
+
+/**
+ * @brief Stop bit length
+ * @note LPUART only supports whole stop bit lengths (i.e. 1 and 2, but not 0.5 and 1.5)
+ */
+typedef enum {
+    FuriHalSerialStopBits0_5,
+    FuriHalSerialStopBits1,
+    FuriHalSerialStopBits1_5,
+    FuriHalSerialStopBits2,
+
+    FuriHalSerialStopBits2Max,
+} FuriHalSerialStopBits;
+
 typedef struct FuriHalSerialHandle FuriHalSerialHandle;