microbit.c

00001 /**
00002  * @file    microbit.c
00003  * @brief   board ID for the BBC Microbit board
00004  *
00005  * DAPLink Interface Firmware
00006  * Copyright (c) 2009-2019, ARM Limited, All Rights Reserved
00007  * SPDX-License-Identifier: Apache-2.0
00008  *
00009  * Licensed under the Apache License, Version 2.0 (the "License"); you may
00010  * not use this file except in compliance with the License.
00011  * You may obtain a copy of the License at
00012  *
00013  * http://www.apache.org/licenses/LICENSE-2.0
00014  *
00015  * Unless required by applicable law or agreed to in writing, software
00016  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00017  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00018  * See the License for the specific language governing permissions and
00019  * limitations under the License.
00020  */
00021 #include "fsl_device_registers.h"
00022 #include "IO_Config.h"
00023 #include "DAP.h"
00024 #include "target_family.h"
00025 #include "target_board.h"
00026 
00027 const char * const board_id_mb_1_3 = "9900";
00028 const char * const board_id_mb_1_5 = "9901";
00029 
00030 typedef enum {
00031     BOARD_VERSION_1_3 = 0,
00032     BOARD_VERSION_1_5 = 1,
00033 } mb_version_t;
00034 
00035 // Enables Board Type Pin, reads it and disables it
00036 // Depends on gpio_init() to have been executed already
00037 static uint8_t read_board_type_pin(void) {
00038     uint8_t pin_state = 0;
00039     // GPIO mode, Pull enable, pull down, input
00040     PIN_BOARD_TYPE_PORT->PCR[PIN_BOARD_TYPE_BIT] = PORT_PCR_MUX(1) | PORT_PCR_PE(1) | PORT_PCR_PS(0);
00041     PIN_BOARD_TYPE_GPIO->PDDR &= ~PIN_BOARD_TYPE;
00042     // Wait to stabilise, based on gpio.c busy_wait(), at -O2 10000 iterations delay ~850us
00043     for (volatile uint32_t i = 10000; i > 0; i--);
00044     // Read pin
00045     pin_state = (PIN_BOARD_TYPE_GPIO->PDIR & PIN_BOARD_TYPE);
00046     // Revert and disable
00047     PIN_BOARD_TYPE_PORT->PCR[PIN_BOARD_TYPE_BIT] = PORT_PCR_MUX(0) | PORT_PCR_PE(0);
00048     return pin_state;
00049 }
00050 
00051 static void set_board_id(mb_version_t board_version) {
00052     switch (board_version) {
00053         case BOARD_VERSION_1_3:
00054             target_device.rt_board_id = board_id_mb_1_3;
00055             break;
00056         case BOARD_VERSION_1_5:
00057             target_device.rt_board_id = board_id_mb_1_5;
00058             break;
00059         default:
00060             target_device.rt_board_id = board_id_mb_1_5;
00061             break;
00062     }
00063 }
00064 
00065 // Called in main_task() to init before USB and files are configured
00066 static void prerun_board_config(void) {
00067     // With only two boards the digital pin read maps directly to the type
00068     mb_version_t board_version = (mb_version_t)read_board_type_pin();
00069     set_board_id(board_version);
00070 }
00071 
00072 // USB HID override function return 1 if the activity is trivial or response is null 
00073 uint8_t usbd_hid_no_activity(uint8_t *buf)
00074 {
00075     if(buf[0] == ID_DAP_Vendor3 &&  buf[1] == 0)
00076         return 1;
00077     else
00078         return 0;
00079 }
00080 
00081 const board_info_t g_board_info = {
00082     .info_version = kBoardInfoVersion,
00083     .family_id = kNordic_Nrf51_FamilyID,
00084     .daplink_url_name =       "MICROBITHTM",
00085     .daplink_drive_name =       "MICROBIT   ",
00086     .daplink_target_url = "https://microbit.org/device/?id=@B&v=@V",
00087     .prerun_board_config = prerun_board_config,
00088     .target_cfg = &target_device,
00089 };