added CDC UART to RP2040 (Pico)

Author: majbthrd

CMakeLists.txt

@@ -26,6 +26,7 @@ if(FAMILY STREQUAL "rp2040")
     ${CMAKE_CURRENT_SOURCE_DIR}/CMSIS_5/CMSIS/DAP/Firmware/Source/DAP_vendor.c
     ${CMAKE_CURRENT_SOURCE_DIR}/CMSIS_5/CMSIS/DAP/Firmware/Source/SWO.c
     ${CMAKE_CURRENT_SOURCE_DIR}/CMSIS_5/CMSIS/DAP/Firmware/Source/SW_DP.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/bsp/${FAMILY}/cdc_uart.c
   )
 
  # Example include

Makefile

@@ -17,6 +17,7 @@ SRC_C += \
     ./CMSIS_5/CMSIS/DAP/Firmware/Source/JTAG_DP.c \
     ./CMSIS_5/CMSIS/DAP/Firmware/Source/DAP_vendor.c \
     ./CMSIS_5/CMSIS/DAP/Firmware/Source/SWO.c \
-    ./CMSIS_5/CMSIS/DAP/Firmware/Source/SW_DP.c
+    ./CMSIS_5/CMSIS/DAP/Firmware/Source/SW_DP.c \
+    ./bsp/$(BOARD)/cdc_uart.c
 
 include ./tinyusb/examples/rules.mk

bsp/rp2040/cdc_uart.c

@@ -0,0 +1,68 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Raspberry Pi (Trading) Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include <pico/stdlib.h>
+
+#include "tusb.h"
+
+#include "picoprobe_config.h"
+
+void cdc_uart_init(void) {
+    gpio_set_function(PICOPROBE_UART_TX, GPIO_FUNC_UART);
+    gpio_set_function(PICOPROBE_UART_RX, GPIO_FUNC_UART);
+    uart_init(PICOPROBE_UART_INTERFACE, PICOPROBE_UART_BAUDRATE);
+}
+
+void cdc_task(void) {
+    uint8_t rx_buf[CFG_TUD_CDC_RX_BUFSIZE];
+    uint8_t tx_buf[CFG_TUD_CDC_TX_BUFSIZE];
+
+    // Consume uart fifo regardless even if not connected
+    uint rx_len = 0;
+    while(uart_is_readable(PICOPROBE_UART_INTERFACE) && (rx_len < sizeof(rx_buf))) {
+        rx_buf[rx_len++] = uart_getc(PICOPROBE_UART_INTERFACE);
+    }
+
+    if (tud_cdc_connected()) {
+        // Do we have anything to display on the host's terminal?
+        if (rx_len) {
+            for (uint i = 0; i < rx_len; i++) {
+                tud_cdc_write_char(rx_buf[i]);
+            }
+            tud_cdc_write_flush();
+        }
+
+        if (tud_cdc_available()) {
+            // Is there any data from the host for us to tx
+            uint tx_len = tud_cdc_read(tx_buf, sizeof(tx_buf));
+            uart_write_blocking(PICOPROBE_UART_INTERFACE, tx_buf, tx_len);
+        }
+    }
+}
+
+void tud_cdc_line_coding_cb(uint8_t itf, cdc_line_coding_t const* line_coding) {
+    picoprobe_info("New baud rate %d\n", line_coding->bit_rate);
+    uart_init(PICOPROBE_UART_INTERFACE, line_coding->bit_rate);
+}

bsp/stm32f072disco/cdc_uart.c

@@ -0,0 +1,7 @@
+void cdc_uart_init(void)
+{
+}
+
+void cdc_task(void)
+{
+}

main.c

@@ -33,16 +33,21 @@
 #include "DAP_config.h" /* ARM code *assumes* this is included prior to DAP.h */
 #include "DAP.h"
 
+void cdc_uart_init(void);
+void cdc_task(void);
+
 int main(void)
 {
   board_init();
+  cdc_uart_init();
   DAP_Setup();
 
   tusb_init();
 
   while (1)
   {
     tud_task(); // tinyusb device task
+    cdc_task();
   }
 
   return 0;

tusb_config.h

@@ -94,7 +94,7 @@
 #endif
 
 //------------- CLASS -------------//
-#define CFG_TUD_CDC               0
+#define CFG_TUD_CDC               1
 #define CFG_TUD_MSC               0
 #define CFG_TUD_HID               1
 #define CFG_TUD_MIDI              0
@@ -103,6 +103,10 @@
 
 #define CFG_TUD_HID_EP_BUFSIZE    64
 
+// CDC FIFO size of TX and RX
+#define CFG_TUD_CDC_RX_BUFSIZE   (TUD_OPT_HIGH_SPEED ? 512 : 64)
+#define CFG_TUD_CDC_TX_BUFSIZE   (TUD_OPT_HIGH_SPEED ? 512 : 64)
+
 #ifdef __cplusplus
  }
 #endif

usb_descriptors.c

@@ -100,20 +100,28 @@ uint8_t const * tud_hid_descriptor_report_cb(void)
 enum
 {
   ITF_NUM_HID,
+  ITF_NUM_CDC_COM,
+  ITF_NUM_CDC_DATA,
   ITF_NUM_TOTAL
 };
 
-#define  CONFIG_TOTAL_LEN  (TUD_CONFIG_DESC_LEN + TUD_HID_INOUT_DESC_LEN)
+#define  CONFIG_TOTAL_LEN  (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN + TUD_HID_INOUT_DESC_LEN)
 
-#define EPNUM_HID   0x01
+#define EPNUM_HID       0x01
+#define EPNUM_CDC_NOTIF 0x83
+#define EPNUM_CDC_OUT   0x02
+#define EPNUM_CDC_IN    0x82
 
 uint8_t const desc_configuration[] =
 {
   // Config number, interface count, string index, total length, attribute, power in mA
   TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, 100),
 
   // Interface number, string index, protocol, report descriptor len, EP In & Out address, size & polling interval
-  TUD_HID_INOUT_DESCRIPTOR(ITF_NUM_HID, 0, HID_PROTOCOL_NONE, sizeof(desc_hid_report), EPNUM_HID, 0x80 | EPNUM_HID, CFG_TUD_HID_EP_BUFSIZE, 1)
+  TUD_HID_INOUT_DESCRIPTOR(ITF_NUM_HID, 0, HID_PROTOCOL_NONE, sizeof(desc_hid_report), EPNUM_HID, 0x80 | EPNUM_HID, CFG_TUD_HID_EP_BUFSIZE, 1),
+
+  // Interface number, string index, EP notification address and size, EP data address (out, in) and size.
+  TUD_CDC_DESCRIPTOR(ITF_NUM_CDC_COM, 0, EPNUM_CDC_NOTIF, 64, EPNUM_CDC_OUT, EPNUM_CDC_IN, 64),
 };
 
 // Invoked when received GET CONFIGURATION DESCRIPTOR