Adds uart.getconfig(0) to get the current uart parameters (#1658)

app/driver/uart.c

@@ -356,3 +356,18 @@ uart_setup(uint8 uart_no)
 void ICACHE_FLASH_ATTR uart_set_alt_output_uart0(void (*fn)(char)) {
   alt_uart0_tx = fn;
 }
+
+UartConfig ICACHE_FLASH_ATTR uart_get_config(uint8 uart_no) {
+  UartConfig config;
+
+  config.baut_rate = UART_CLK_FREQ / READ_PERI_REG(UART_CLKDIV(uart_no));
+
+  uint32_t conf = READ_PERI_REG(UART_CONF0(uart_no));
+
+  config.exist_parity = (conf >> UART_PARITY_EN_S)    & UART_PARITY_EN_M;
+  config.parity       = (conf >> UART_PARITY_S)       & UART_PARITY_M;
+  config.stop_bits    = (conf >> UART_STOP_BIT_NUM_S) & UART_STOP_BIT_NUM;
+  config.data_bits    = (conf >> UART_BIT_NUM_S)      & UART_BIT_NUM;
+
+  return config;
+}

app/include/driver/uart.h

@@ -101,7 +101,16 @@ typedef struct {
     int                      buff_uart_no;  //indicate which uart use tx/rx buffer
 } UartDevice;
 
+typedef struct {
+    UartBautRate      baut_rate;
+    UartBitsNum4Char  data_bits;
+    UartExistParity   exist_parity;
+    UartParityMode    parity;   
+    UartStopBitsNum   stop_bits;
+} UartConfig;
+
 void uart_init(UartBautRate uart0_br, UartBautRate uart1_br, os_signal_t sig_input, uint8 *flag_input);
+UartConfig uart_get_config(uint8 uart_no);
 void uart0_alt(uint8 on);
 void uart0_sendStr(const char *str);
 void uart0_putc(const char c);

app/modules/uart.c

@@ -27,7 +27,7 @@ bool uart_on_data_cb(const char *buf, size_t len){
 uint16_t need_len = 0;
 int16_t end_char = -1;
 // Lua: uart.on("method", [number/char], function, [run_input])
-static int uart_on( lua_State* L )
+static int l_uart_on( lua_State* L )
 {
   size_t sl, el;
   int32_t run = 1;
@@ -89,13 +89,14 @@ static int uart_on( lua_State* L )
 
 bool uart0_echo = true;
 // Lua: actualbaud = setup( id, baud, databits, parity, stopbits, echo )
-static int uart_setup( lua_State* L )
+static int l_uart_setup( lua_State* L )
 {
-  unsigned id, databits, parity, stopbits, echo = 1;
+  uint32_t id, databits, parity, stopbits, echo = 1;
-  u32 baud, res;
+  uint32_t baud, res;
   
   id = luaL_checkinteger( L, 1 );
   MOD_CHECK_ID( uart, id );
+
   baud = luaL_checkinteger( L, 2 );
   databits = luaL_checkinteger( L, 3 );
   parity = luaL_checkinteger( L, 4 );
@@ -113,8 +114,26 @@ static int uart_setup( lua_State* L )
   return 1;
 }
 
+// uart.getconfig(id)
+static int l_uart_getconfig( lua_State* L )
+{
+  uint32_t id, databits, parity, stopbits;
+  uint32_t baud;
+  
+  id = luaL_checkinteger( L, 1 );
+  MOD_CHECK_ID( uart, id );
+
+  platform_uart_get_config(id, &baud, &databits, &parity, &stopbits);
+
+  lua_pushinteger(L, baud);
+  lua_pushinteger(L, databits);
+  lua_pushinteger(L, parity);
+  lua_pushinteger(L, stopbits);
+  return 4;
+}
+
 // Lua: alt( set )
-static int uart_alt( lua_State* L )
+static int l_uart_alt( lua_State* L )
 {
   unsigned set;
   
@@ -125,7 +144,7 @@ static int uart_alt( lua_State* L )
 }
 
 // Lua: write( id, string1, [string2], ..., [stringn] )
-static int uart_write( lua_State* L )
+static int l_uart_write( lua_State* L )
 {
   int id;
   const char* buf;
@@ -156,10 +175,11 @@ static int uart_write( lua_State* L )
 
 // Module function map
 static const LUA_REG_TYPE uart_map[] =  {
-  { LSTRKEY( "setup" ), LFUNCVAL( uart_setup ) },
+  { LSTRKEY( "setup" ), LFUNCVAL( l_uart_setup ) },
-  { LSTRKEY( "write" ), LFUNCVAL( uart_write ) },
+  { LSTRKEY( "getconfig" ), LFUNCVAL( l_uart_getconfig ) },
-  { LSTRKEY( "on" ),    LFUNCVAL( uart_on ) },
+  { LSTRKEY( "write" ), LFUNCVAL( l_uart_write ) },
-  { LSTRKEY( "alt" ),   LFUNCVAL( uart_alt ) },
+  { LSTRKEY( "on" ),    LFUNCVAL( l_uart_on ) },
+  { LSTRKEY( "alt" ),   LFUNCVAL( l_uart_alt ) },
   { LSTRKEY( "STOPBITS_1" ),   LNUMVAL( PLATFORM_UART_STOPBITS_1 ) },
   { LSTRKEY( "STOPBITS_1_5" ), LNUMVAL( PLATFORM_UART_STOPBITS_1_5 ) },
   { LSTRKEY( "STOPBITS_2" ),   LNUMVAL( PLATFORM_UART_STOPBITS_2 ) },

app/platform/platform.c

@@ -32,6 +32,26 @@ static struct gpio_hook platform_gpio_hook;
 #endif
 #endif
 
+static const int uart_bitrates[] = {
+    BIT_RATE_300,
+    BIT_RATE_600,
+    BIT_RATE_1200,
+    BIT_RATE_2400,
+    BIT_RATE_4800,
+    BIT_RATE_9600,
+    BIT_RATE_19200,
+    BIT_RATE_38400,
+    BIT_RATE_57600,
+    BIT_RATE_74880,
+    BIT_RATE_115200,
+    BIT_RATE_230400,
+    BIT_RATE_256000,
+    BIT_RATE_460800,
+    BIT_RATE_921600,
+    BIT_RATE_1843200,
+    BIT_RATE_3686400
+};
+
 int platform_init()
 {
   // Setup the various forward and reverse mappings for the pins
@@ -410,6 +430,64 @@ uint32_t platform_uart_setup( unsigned id, uint32_t baud, int databits, int pari
   return baud;
 }
 
+void platform_uart_get_config(unsigned id, uint32_t *baudp, uint32_t *databitsp, uint32_t *parityp, uint32_t *stopbitsp) {
+  UartConfig config =  uart_get_config(id);
+  int i;
+
+  int offset = config.baut_rate;
+
+  for (i = 0; i < sizeof(uart_bitrates) / sizeof(uart_bitrates[0]); i++) {
+    int diff = config.baut_rate - uart_bitrates[i];
+
+    if (diff < 0) {
+      diff = -diff;
+    }
+
+    if (diff < offset) {
+       offset = diff;
+       *baudp = uart_bitrates[i];
+    }
+  }
+
+  switch( config.data_bits )
+  {
+    case FIVE_BITS:
+      *databitsp = 5;
+      break;
+    case SIX_BITS:
+      *databitsp = 6;
+      break;
+    case SEVEN_BITS:
+      *databitsp = 7;
+      break;
+    case EIGHT_BITS:
+    default:
+      *databitsp = 8;
+      break;
+  }
+
+  switch (config.stop_bits)
+  {
+    case ONE_HALF_STOP_BIT:
+      *stopbitsp = PLATFORM_UART_STOPBITS_1_5;
+      break;
+    case TWO_STOP_BIT:
+      *stopbitsp = PLATFORM_UART_STOPBITS_2;
+      break;
+    default:
+      *stopbitsp = PLATFORM_UART_STOPBITS_1;
+      break;
+  }
+
+  if (config.exist_parity == STICK_PARITY_DIS) {
+    *parityp = PLATFORM_UART_PARITY_NONE;
+  } else if (config.parity == EVEN_BITS) {
+    *parityp = PLATFORM_UART_PARITY_EVEN;
+  } else {
+    *parityp = PLATFORM_UART_PARITY_ODD;
+  }
+}
+
 // if set=1, then alternate serial output pins are used. (15=rx, 13=tx)
 void platform_uart_alt( int set )
 {

app/platform/platform.h

@@ -7,6 +7,7 @@
 
 #include "c_types.h"
 #include "driver/pwm.h"
+#include "driver/uart.h"
 #include "task/task.h"
 
 // Error / status codes
@@ -161,6 +162,7 @@ int platform_s_uart_recv( unsigned id, timer_data_type timeout );
 int platform_uart_set_flow_control( unsigned id, int type );
 int platform_s_uart_set_flow_control( unsigned id, int type );
 void platform_uart_alt( int set );
+void platform_uart_get_config(unsigned id, uint32_t *baudp, uint32_t *databitsp, uint32_t *parityp, uint32_t *stopbitsp);
 
 // *****************************************************************************
 // PWM subsection

docs/en/modules/uart.md

@@ -67,7 +67,7 @@ end, 0)
 
 ## uart.setup()
 
-(Re-)configures the communication parameters of the UART.
+(Re-)configures the communication parameters of the UART. 
 
 #### Syntax
 `uart.setup(id, baud, databits, parity, stopbits, echo)`
@@ -89,6 +89,32 @@ configured baud rate (number)
 uart.setup(0, 9600, 8, uart.PARITY_NONE, uart.STOPBITS_1, 1)
 ```
 
+## uart.getconfig()
+
+Returns the current configuration parameters of the UART. 
+
+#### Syntax
+`uart.getconfig(id)`
+
+#### Parameters
+- `id` always zero, only one uart supported
+
+#### Returns
+Four values as follows:
+
+- `baud` one of 300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 74880, 115200, 230400, 256000, 460800, 921600, 1843200, 3686400
+- `databits` one of 5, 6, 7, 8
+- `parity` `uart.PARITY_NONE`, `uart.PARITY_ODD`, or `uart.PARITY_EVEN`
+- `stopbits` `uart.STOPBITS_1`, `uart.STOPBITS_1_5`, or `uart.STOPBITS_2`
+
+#### Example
+```lua
+print (uart.getconfig(0))
+-- prints 9600 8 0 1   for 9600, 8N1
+```
+
+
+
 ## uart.write()
 
 Write string or byte to the UART.