board bringup: adc, usart working

1 files changed, 175 insertions, 0 deletions

diff --git a/gm_platform/fw/main.c b/gm_platform/fw/main.c
new file mode 100644
index 0000000..d2bc33c
--- /dev/null
+++ b/gm_platform/fw/main.c
@@ -0,0 +1,175 @@
+/* Megumin LED display firmware
+ * Copyright (C) 2018 Sebastian Götte <code@jaseg.net>
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "global.h"
+#include "adc.h"
+#include "serial.h"
+
+
+volatile unsigned int sys_time_seconds = 0;
+
+void update_leds() {
+
+}
+
+volatile union {
+    struct {
+        unsigned int usb, ocxo, error, _nc1, _nc2, _nc3, pps, sd_card;
+    };
+    unsigned int arr[0];
+} leds;
+
+int main(void) {
+    RCC->CR |= RCC_CR_HSEON;
+    while (!(RCC->CR&RCC_CR_HSERDY));
+    RCC->CFGR &= ~RCC_CFGR_PLLMUL_Msk & ~RCC_CFGR_SW_Msk & ~RCC_CFGR_PPRE_Msk & ~RCC_CFGR_HPRE_Msk;
+    RCC->CFGR |= ((6-2)<<RCC_CFGR_PLLMUL_Pos) | RCC_CFGR_PLLSRC_HSE_PREDIV; /* PLL x6 -> 48.0MHz */
+    RCC->CR |= RCC_CR_PLLON;
+    while (!(RCC->CR&RCC_CR_PLLRDY));
+    RCC->CFGR |= (2<<RCC_CFGR_SW_Pos);
+    SystemCoreClockUpdate();
+    SysTick_Config(SystemCoreClock/10); /* 100ms interval */
+    NVIC_EnableIRQ(SysTick_IRQn);
+    NVIC_SetPriority(SysTick_IRQn, 3<<5);
+
+    /* Turn on lots of neat things */
+    RCC->AHBENR  |= RCC_AHBENR_DMAEN | RCC_AHBENR_GPIOAEN | RCC_AHBENR_GPIOBEN | RCC_AHBENR_FLITFEN;
+    RCC->APB2ENR |= RCC_APB2ENR_SYSCFGEN | RCC_APB2ENR_ADCEN | RCC_APB2ENR_SPI1EN | RCC_APB2ENR_DBGMCUEN |\
+                    RCC_APB2ENR_TIM1EN | RCC_APB2ENR_TIM16EN | RCC_APB2ENR_USART1EN;
+    RCC->APB1ENR |= RCC_APB1ENR_TIM3EN;
+
+    GPIOA->MODER |=
+          (3<<GPIO_MODER_MODER2_Pos)  /* PA2  - LINE_MEAS */
+        | (1<<GPIO_MODER_MODER3_Pos)  /* PA3  - LED_STB */
+        | (1<<GPIO_MODER_MODER4_Pos)  /* PA4  - SD_CS */
+        | (2<<GPIO_MODER_MODER5_Pos)  /* PA5  - SCK */
+        | (2<<GPIO_MODER_MODER6_Pos)  /* PA6  - MISO */
+        | (2<<GPIO_MODER_MODER7_Pos)  /* PA7  - MOSI */
+        | (2<<GPIO_MODER_MODER9_Pos)  /* PA9  - HOST_RX */
+        | (2<<GPIO_MODER_MODER10_Pos);/* PA10 - HOST_TX */
+
+    /* Set shift register IO GPIO output speed */
+    GPIOA->OSPEEDR |=
+          (2<<GPIO_OSPEEDR_OSPEEDR3_Pos)   /* LED_STB */
+        | (2<<GPIO_OSPEEDR_OSPEEDR4_Pos)   /* SD_CS */
+        | (2<<GPIO_OSPEEDR_OSPEEDR5_Pos)   /* SCK */
+        | (2<<GPIO_OSPEEDR_OSPEEDR7_Pos)   /* MOSI */
+        | (2<<GPIO_OSPEEDR_OSPEEDR9_Pos);  /* HOST_RX */
+
+    GPIOA->AFR[0] = (0<<GPIO_AFRL_AFRL5_Pos) | (0<<GPIO_AFRL_AFRL6_Pos) | (0<<GPIO_AFRL_AFRL7_Pos);
+    GPIOA->AFR[1] = (1<<8) | (1<<4);
+
+    GPIOB->MODER |=
+          (0<<GPIO_MODER_MODER1_Pos); /* PB0  - LINE_POL */
+
+    SPI1->CR1 =
+          SPI_CR1_SSM
+        | SPI_CR1_SSI
+        | (4<<SPI_CR1_BR_Pos) /* /32 ~1.5MHz */
+        | SPI_CR1_MSTR;
+    SPI1->CR2 = (7<<SPI_CR2_DS_Pos);
+    SPI1->CR1 |= SPI_CR1_SPE;
+
+    NVIC_EnableIRQ(SPI1_IRQn);
+    NVIC_SetPriority(SPI1_IRQn, 2<<5);
+
+    TIM16->CR2 = 0;
+    TIM16->DIER = TIM_DIER_UIE;
+    TIM16->PSC = 48-1; /* 1us */
+    TIM16->ARR = 1000-1; /* 1ms */
+    TIM16->CR1 = TIM_CR1_CEN;
+
+    NVIC_EnableIRQ(TIM16_IRQn);
+    NVIC_SetPriority(TIM16_IRQn, 2<<5);
+
+    adc_configure_scope_mode(1000000);
+
+    usart_dma_init();
+
+    while (42) {
+        char *data = "FOOBAR\n";
+        usart_send_packet((uint8_t*)data, 8);
+        for (int i=0; i<100000; i++);
+        //int pol = GPIOB->IDR & (1<<1); /* Sample current polarity */
+        //leds.error = pol ? 100 : 0;
+        //for (int i=0; i<10000; i++) ;
+        //leds.error = 100;
+    }
+}
+
+void SPI1_IRQHandler(void) {
+    if (SPI1->SR & SPI_SR_TXE) {
+        /* LED_STB */
+        GPIOA->BSRR = 1<<3;
+        SPI1->CR2 &= ~SPI_CR2_TXEIE;
+    }
+}
+
+void TIM16_IRQHandler(void) {
+    static int leds_update_counter = 0;
+    if (TIM16->SR & TIM_SR_UIF) {
+        TIM16->SR &= ~TIM_SR_UIF;
+
+        uint8_t bits = 0, mask = 1;
+        for (size_t i=0; i<sizeof(leds)/sizeof(leds.arr[0]); i++) {
+            if (leds.arr[i]) {
+                leds.arr[i]--;
+                bits |= mask;
+            }
+            mask <<= 1;
+        }
+
+        if (leds_update_counter++ == 10) {
+            leds_update_counter = 0;
+
+            /* Workaround for SPI hardware bug: Even if configured to 8-bit mode, the SPI will do a 16-bit transfer if the
+             * data register is accessed through a 16-bit write. Unfortunately, the STMCube register defs define DR as an
+             * uint16_t, so we have to do some magic here to force an 8-bit write. */
+            *((volatile uint8_t*)&(SPI1->DR)) = bits;
+            SPI1->CR2 |= SPI_CR2_TXEIE;
+            GPIOA->BRR = 1<<3;
+        }
+    }
+}
+
+void NMI_Handler(void) {
+    asm volatile ("bkpt");
+}
+
+void HardFault_Handler(void) __attribute__((naked));
+void HardFault_Handler() {
+    asm volatile ("bkpt");
+}
+
+void SVC_Handler(void) {
+    asm volatile ("bkpt");
+}
+
+
+void PendSV_Handler(void) {
+    asm volatile ("bkpt");
+}
+
+void SysTick_Handler(void) {
+    static int n = 0;
+    if (n++ == 10) {
+        n = 0;
+        sys_time_seconds++;
+        leds.pps = 100; /* ms */
+    }
+}
+