stmhal: Fix escape sequences in USB CDC input.

5 files changed, 41 insertions, 33 deletions

diff --git a/stmhal/pyexec.c b/stmhal/pyexec.c
index 75709bb6a..ecdd4d8c6 100644
--- a/stmhal/pyexec.c
+++ b/stmhal/pyexec.c
@@ -49,7 +49,7 @@ int stdin_rx_chr(void) {
         }
 #endif
 #endif
-        if (usb_vcp_rx_any() != 0) {
+        if (usb_vcp_rx_num() != 0) {
             return usb_vcp_rx_get();
         } else if (pyb_usart_global_debug != PYB_USART_NONE && usart_rx_any(pyb_usart_global_debug)) {
             return usart_rx_char(pyb_usart_global_debug);
@@ -78,14 +78,16 @@ static const char *readline_hist[READLINE_HIST_SIZE] = {NULL, NULL, NULL, NULL,
 int readline(vstr_t *line, const char *prompt) {
     stdout_tx_str(prompt);
     int len = vstr_len(line);
-    int escape = 0;
+    int escape_seq = 0;
     int hist_num = 0;
     for (;;) {
         int c = stdin_rx_chr();
-        if (escape == 0) {
+        if (escape_seq == 0) {
             if (VCP_CHAR_CTRL_A <= c && c <= VCP_CHAR_CTRL_D && vstr_len(line) == len) {
+                // control character with empty line
                 return c;
             } else if (c == '\r') {
+                // newline
                 stdout_tx_str("\r\n");
                 for (int i = READLINE_HIST_SIZE - 1; i > 0; i--) {
                     readline_hist[i] = readline_hist[i - 1];
@@ -93,24 +95,27 @@ int readline(vstr_t *line, const char *prompt) {
                 readline_hist[0] = str_dup(vstr_str(line));
                 return 0;
             } else if (c == 27) {
-                escape = true;
+                // escape sequence
+                escape_seq = 1;
             } else if (c == 127) {
+                // backspace
                 if (vstr_len(line) > len) {
                     vstr_cut_tail(line, 1);
                     stdout_tx_str("\b \b");
                 }
             } else if (32 <= c && c <= 126) {
+                // printable character
                 vstr_add_char(line, c);
                 stdout_tx_str(line->buf + line->len - 1);
             }
-        } else if (escape == 1) {
+        } else if (escape_seq == 1) {
             if (c == '[') {
-                escape = 2;
+                escape_seq = 2;
             } else {
-                escape = 0;
+                escape_seq = 0;
             }
-        } else if (escape == 2) {
-            escape = 0;
+        } else if (escape_seq == 2) {
+            escape_seq = 0;
             if (c == 'A') {
                 // up arrow
                 if (hist_num < READLINE_HIST_SIZE && readline_hist[hist_num] != NULL) {
@@ -128,7 +133,7 @@ int readline(vstr_t *line, const char *prompt) {
                 }
             }
         } else {
-            escape = 0;
+            escape_seq = 0;
         }
         HAL_Delay(1);
     }
diff --git a/stmhal/usb.c b/stmhal/usb.c
index e6e994a0f..21b88f9a1 100644
--- a/stmhal/usb.c
+++ b/stmhal/usb.c
@@ -71,8 +71,8 @@ void usb_vcp_set_interrupt_char(int c) {
     }
 }
 
-int usb_vcp_rx_any(void) {
-    return USBD_CDC_RxAny();
+int usb_vcp_rx_num(void) {
+    return USBD_CDC_RxNum();
 }
 
 char usb_vcp_rx_get(void) {
diff --git a/stmhal/usb.h b/stmhal/usb.h
index a0fb15324..3e6bdccec 100644
--- a/stmhal/usb.h
+++ b/stmhal/usb.h
@@ -11,7 +11,7 @@ void pyb_usb_dev_init(int usb_dev_type);
 bool usb_vcp_is_enabled(void);
 bool usb_vcp_is_connected(void);
 void usb_vcp_set_interrupt_char(int c);
-int usb_vcp_rx_any(void);
+int usb_vcp_rx_num(void);
 char usb_vcp_rx_get(void);
 void usb_vcp_send_str(const char* str);
 void usb_vcp_send_strn(const char* str, int len);
diff --git a/stmhal/usbd_cdc_interface.c b/stmhal/usbd_cdc_interface.c
index 49f108ffd..e441c0b51 100644
--- a/stmhal/usbd_cdc_interface.c
+++ b/stmhal/usbd_cdc_interface.c
@@ -44,28 +44,23 @@
 

 /* Private typedef -----------------------------------------------------------*/

 /* Private define ------------------------------------------------------------*/

-#define APP_RX_DATA_SIZE  2048 // I think this must be at least CDC_DATA_FS_OUT_PACKET_SIZE

-#define APP_TX_DATA_SIZE  2048 // I think this can be any value

+#define APP_RX_DATA_SIZE  1024 // I think this must be at least CDC_DATA_FS_OUT_PACKET_SIZE (was 2048)

+#define APP_TX_DATA_SIZE  1024 // I think this can be any value (was 2048)

 

 /* Private macro -------------------------------------------------------------*/

 /* Private variables ---------------------------------------------------------*/

 

-uint8_t UserRxBuffer[APP_RX_DATA_SIZE];/* Received Data over USB are stored in this buffer */

-uint32_t UserRxBufLen; // counts number of valid characters in UserRxBuffer

+static uint8_t UserRxBuffer[APP_RX_DATA_SIZE]; // received data from USB OUT endpoint is stored in this buffer

+static uint16_t UserRxBufCur = 0; // points to next available character in UserRxBuffer

+static uint16_t UserRxBufLen = 0; // counts number of valid characters in UserRxBuffer

 

-uint8_t UserTxBuffer[APP_TX_DATA_SIZE];/* Received Data over UART (CDC interface) are stored in this buffer */

-uint32_t UserTxBufPtrIn = 0;/* Increment this pointer or roll it back to

-                               start address when data are received over USART */

-uint32_t UserTxBufPtrOut = 0; /* Increment this pointer or roll it back to

-                                 start address when data are sent over USB */

+static uint8_t UserTxBuffer[APP_TX_DATA_SIZE]; // data for USB IN endpoind is stored in this buffer

+static uint16_t UserTxBufPtrIn = 0; // increment this pointer modulo APP_TX_DATA_SIZE when new data is available

+static uint16_t UserTxBufPtrOut = 0; // increment this pointer modulo APP_TX_DATA_SIZE when data is drained

 

 static int user_interrupt_char = VCP_CHAR_NONE;

 static void *user_interrupt_data = NULL;

 

-#if 0

-/* UART handler declaration */

-UART_HandleTypeDef UartHandle;

-#endif

 /* TIM handler declaration */

 TIM_HandleTypeDef USBD_CDC_TimHandle;

 /* USB handler declaration */

@@ -145,7 +140,9 @@ static int8_t CDC_Itf_Init(void)
   /*##-5- Set Application Buffers ############################################*/

   USBD_CDC_SetTxBuffer(&hUSBDDevice, UserTxBuffer, 0);

   USBD_CDC_SetRxBuffer(&hUSBDDevice, UserRxBuffer);

-  UserRxBufLen = 0;

+

+    UserRxBufCur = 0;

+    UserRxBufLen = 0;

   

     user_interrupt_char = VCP_CHAR_NONE;

     user_interrupt_data = NULL;

@@ -357,6 +354,9 @@ static int8_t CDC_Itf_Receive(uint8_t* Buf, uint32_t *Len) {
         }

     }

 

+    // there are new characters at the start of the buffer, so point there

+    UserRxBufCur = 0;

+

     if (UserRxBufLen == 0) {

         // initiate next USB packet transfer now that UserRxBuffer has been drained

         USBD_CDC_ReceivePacket(&hUSBDDevice);

@@ -377,16 +377,19 @@ void USBD_CDC_Tx(const char *str, uint32_t len) {
     }

 }

 

-int USBD_CDC_RxAny(void) {

-    return UserRxBufLen;

+int USBD_CDC_RxNum(void) {

+    return UserRxBufLen - UserRxBufCur;

 }

 

 int USBD_CDC_RxGet(void) {

-    while (UserRxBufLen == 0) {

+    // wait for buffer to have at least 1 character in it

+    while (USBD_CDC_RxNum() == 0) {

         __WFI();

     }

-    int c = UserRxBuffer[--UserRxBufLen];

-    if (UserRxBufLen == 0) {

+

+    // get next character

+    int c = UserRxBuffer[UserRxBufCur++];

+    if (UserRxBufCur >= UserRxBufLen) {

         // initiate next USB packet transfer now that UserRxBuffer has been drained

         USBD_CDC_ReceivePacket(&hUSBDDevice);

     }

diff --git a/stmhal/usbd_cdc_interface.h b/stmhal/usbd_cdc_interface.h
index cabd68c1e..3411893ae 100644
--- a/stmhal/usbd_cdc_interface.h
+++ b/stmhal/usbd_cdc_interface.h
@@ -51,7 +51,7 @@ extern USBD_CDC_ItfTypeDef USBD_CDC_fops;
 

 void USBD_CDC_SetInterrupt(int chr, void *data);

 void USBD_CDC_Tx(const char *str, uint32_t len);

-int USBD_CDC_RxAny(void);

+int USBD_CDC_RxNum(void);

 int USBD_CDC_RxGet(void);

 

 /* Exported macro ------------------------------------------------------------*/