simplify board API, adding stm32f3 discovery

- remove board header since it is not used

hw/bsp/stm32f303disc/board_stm32f303disc.c

@@ -0,0 +1,122 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018, hathach (tinyusb.org)
+ *
+ * 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.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#include "../board.h"
+#include "stm32f3xx.h"
+
+#include "tusb_option.h"
+
+void board_init(void)
+{
+  // Init the LED on PD14
+  RCC->AHB1ENR |= RCC_AHB1ENR_GPIODEN;
+  GPIOD->MODER |= GPIO_MODER_MODE14_0;
+
+  // USB Clock init
+  // PLL input- 8 MHz (External oscillator clock; HSI clock tolerance isn't
+  // tight enough- 1%, need 0.25%)
+  // VCO input- 1 to 2 MHz (2 MHz, M = 4)
+  // VCO output- 100 to 432 MHz (144 MHz, N = 72)
+  // Main PLL out- <= 180 MHz (18 MHz, P = 3- divides by 8)
+  // USB PLL out- 48 MHz (Q = 3)
+  RCC->PLLCFGR = RCC_PLLCFGR_PLLSRC_HSE | (3 << RCC_PLLCFGR_PLLQ_Pos) | \
+    (3 << RCC_PLLCFGR_PLLP_Pos) | (72 << RCC_PLLCFGR_PLLN_Pos) | \
+    (4 << RCC_PLLCFGR_PLLM_Pos);
+
+  // Wait for external clock to become ready
+  RCC->CR |= RCC_CR_HSEON;
+  while(!(RCC->CR & RCC_CR_HSERDY_Msk));
+
+  // Wait for PLL to become ready
+  RCC->CR |= RCC_CR_PLLON;
+  while(!(RCC->CR & RCC_CR_PLLRDY_Msk));
+
+  // Switch clocks!
+  RCC->CFGR |= RCC_CFGR_SW_1;
+
+  // Notify runtime of frequency change.
+  SystemCoreClockUpdate();
+  // Systick init
+  #if CFG_TUSB_OS  == OPT_OS_NONE
+    SysTick_Config(SystemCoreClock / 1000);
+  #endif
+
+  RCC->AHB2ENR |= RCC_AHB2ENR_OTGFSEN;
+
+  // USB Pin Init
+  // PA9- VUSB, PA10- ID, PA11- DM, PA12- DP
+  // PC0- Power on
+  RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN;
+  GPIOA->MODER |= GPIO_MODER_MODE9_1 | GPIO_MODER_MODE10_1 | \
+    GPIO_MODER_MODE11_1 | GPIO_MODER_MODE12_1;
+  GPIOA->AFR[1] |= (10 << GPIO_AFRH_AFSEL9_Pos) | \
+    (10 << GPIO_AFRH_AFSEL10_Pos) | (10 << GPIO_AFRH_AFSEL11_Pos) | \
+    (10 << GPIO_AFRH_AFSEL12_Pos);
+
+  // Pullup required on ID, despite the manual claiming there's an
+  // internal pullup already (page 1245, Rev 17)
+  GPIOA->PUPDR |= GPIO_PUPDR_PUPD10_0;
+}
+
+
+void board_led_control(bool state)
+{
+  if (!state) {
+    GPIOD->BSRR = GPIO_BSRR_BR14;
+  } else {
+    GPIOD->BSRR = GPIO_BSRR_BS14;
+  }
+}
+
+
+/*------------------------------------------------------------------*/
+/* TUSB HAL MILLISECOND
+ *------------------------------------------------------------------*/
+#if CFG_TUSB_OS  == OPT_OS_NONE
+volatile uint32_t system_ticks = 0;
+
+void SysTick_Handler (void)
+{
+  system_ticks++;
+}
+
+uint32_t tusb_hal_millis(void)
+{
+  return board_tick2ms(system_ticks);
+}
+#endif
+
+void HardFault_Handler (void)
+{
+  asm("bkpt");
+}
+
+// Required by __libc_init_array in startup code if we are compiling using
+// -nostdlib/-nostartfiles.
+void _init(void)
+{
+
+}