1 files changed, 355 insertions, 0 deletions
diff --git a/apps/i2c1/i2c1.cpp b/apps/i2c1/i2c1.cpp
new file mode 100644
index 0000000..b6d0a27
--- /dev/null
+++ b/apps/i2c1/i2c1.cpp
@@ -0,0 +1,355 @@
+#include <cstdint>
+#include <cstring>
+#include <stm32f10x_conf.h>
+#include <stm32f10x.h>
+#include <stm32f10x_rcc.h>
+#include <stm32f10x_gpio.h>
+#include <stm32f10x_i2c.h>
+#include <inttypes.h>
+#include <playground.h>
+#include "debug.h"
+#include "tinyprintf.h"
+
+extern "C" void halt();
+
+extern "C"
+__attribute__((naked))
+void HardFault_Handler_C(uint32_t *hardfault_args) {
+    dbg_printf("r0  = 0x%08lx (%lu)\n", hardfault_args[0], hardfault_args[0]);
+    dbg_printf("r1  = 0x%08lx (%lu)\n", hardfault_args[1], hardfault_args[1]);
+    dbg_printf("r2  = 0x%08lx (%lu)\n", hardfault_args[2], hardfault_args[2]);
+    dbg_printf("r3  = 0x%08lx (%lu)\n", hardfault_args[3], hardfault_args[3]);
+    dbg_printf("r12 = 0x%08lx (%lu)\n", hardfault_args[4], hardfault_args[4]);
+    dbg_printf("lr  = 0x%08lx (%lu)\n", hardfault_args[5], hardfault_args[5]);
+    dbg_printf("pc  = 0x%08lx (%lu)\n", hardfault_args[6], hardfault_args[6]);
+    dbg_printf("psr = 0x%08lx (%lu)\n", hardfault_args[7], hardfault_args[7]);
+    dbg_printf("\n");
+
+    halt();
+}
+
+size_t strlen(const char *s) {
+    size_t size = 0;
+    while (*s++ != '\0') size++;
+    return size;
+}
+
+bool run = true;
+
+volatile USART_TypeDef *usart1 = (volatile USART_TypeDef *) USART1_BASE;
+volatile I2C_TypeDef *i2c1 = (volatile I2C_TypeDef *) I2C1_BASE;
+volatile I2C_TypeDef *i2c2 = (volatile I2C_TypeDef *) I2C2_BASE;
+
+extern "C"
+void assert_failed(uint8_t *file, uint32_t line) {
+    dbg_printf("assert_failed: %s: %" PRIu32 "\n", file, line);
+}
+
+int start_wait_count;
+
+void i2c_hard_reset(I2C_TypeDef *I2Cx, I2C_InitTypeDef &i2c_init) {
+    dbg_printf("start_wait_count=%d\n", start_wait_count);
+    I2C_DeInit(I2Cx);
+    I2C_Cmd(I2Cx, DISABLE);
+    I2C_Init(I2Cx, &i2c_init);
+
+    GPIO_InitTypeDef init;
+    GPIO_StructInit(&init);
+    init.GPIO_Pin = GPIO_Pin_10;
+    init.GPIO_Mode = GPIO_Mode_Out_PP;
+    GPIO_Init(GPIOB, &init);
+
+    GPIO_WriteBit(GPIOB, GPIO_Pin_10, Bit_RESET);
+    for (int i = 0; i < 8; i++) {
+        GPIO_WriteBit(GPIOB, GPIO_Pin_10, Bit_SET);
+        GPIO_WriteBit(GPIOB, GPIO_Pin_10, Bit_RESET);
+    }
+
+    init.GPIO_Pin = GPIO_Pin_10;
+    init.GPIO_Mode = GPIO_Mode_AF_OD;
+    GPIO_Init(GPIOB, &init);
+
+    I2C_Cmd(I2Cx, ENABLE);
+
+    I2C_SoftwareResetCmd(I2Cx, ENABLE);
+    for (int i = 0; i < 100; i++) {
+        __NOP();
+    }
+    I2C_SoftwareResetCmd(I2Cx, DISABLE);
+}
+
+static inline bool i2c_wait_for_flag(I2C_TypeDef *I2Cx, uint32_t flag, FlagStatus status, unsigned int timeout) {
+    do {
+        auto flagStatus = I2C_GetFlagStatus(I2Cx, flag);
+        if (flagStatus == status) {
+            return true;
+        }
+    } while (timeout-- > 0);
+
+    return false;
+}
+
+static inline bool i2c_wait_for_event(I2C_TypeDef *I2Cx, uint32_t expected, unsigned int timeout) {
+    uint32_t actual;
+    do {
+        actual = I2C_GetLastEvent(I2Cx);
+        if (actual == expected) {
+            return true;
+        }
+    } while (timeout-- > 0);
+
+    dbg_printf("i2c_wait_for_event, expected=%08" PRIx32 ", actual=%08" PRIx32 "\n", expected, actual);
+
+    return false;
+}
+
+const unsigned int timeout = 1000 * 1000;
+
+bool i2c_write(I2C_TypeDef *port, uint8_t address, uint8_t *buf, uint8_t count, bool generate_stop) {
+    if (!i2c_wait_for_flag(port, I2C_FLAG_BUSY, RESET, timeout)) {
+        dbg_printf("Failed while waiting for I2C_FLAG_BUSY\n");
+        return false;
+    }
+
+    I2C_GenerateSTART(port, ENABLE);
+
+    if (!i2c_wait_for_event(port, I2C_EVENT_MASTER_MODE_SELECT, timeout)) {
+        dbg_printf("Failed while waiting for I2C_EVENT_MASTER_MODE_SELECT\n");
+        return false;
+    }
+
+    I2C_Send7bitAddress(port, address, I2C_Direction_Transmitter);
+
+    if (!i2c_wait_for_event(port, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED, timeout)) {
+        dbg_printf("Failed while waiting for I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED\n");
+        return false;
+    }
+
+    do {
+        I2C_SendData(port, *buf++);
+
+        if (!i2c_wait_for_event(port, I2C_EVENT_MASTER_BYTE_TRANSMITTED, timeout)) {
+            dbg_printf("Failed while waiting for I2C_EVENT_MASTER_BYTE_TRANSMITTED\n");
+            return false;
+        }
+    } while (--count);
+
+    if (generate_stop) {
+        I2C_GenerateSTOP(port, ENABLE);
+
+        while (I2C_GetFlagStatus(port, I2C_FLAG_STOPF)) {
+            __NOP();
+        }
+    }
+
+    return true;
+}
+
+bool i2c_read(I2C_TypeDef *port, uint8_t address, uint8_t *buf, uint8_t count, bool generate_start) {
+    start_wait_count = 0;
+    int dbg_counter = 0;
+    (void) dbg_counter;
+
+    if (generate_start) {
+        if (!i2c_wait_for_flag(port, I2C_FLAG_BUSY, RESET, timeout)) {
+            dbg_printf("Failed while waiting for I2C_FLAG_BUSY\n");
+            return false;
+        }
+
+        I2C_AcknowledgeConfig(port, ENABLE);
+//    dbg_printf("%2d SR2 SR1 = %08" PRIx32 "\n", dbg_counter, I2C_GetLastEvent(port));
+        I2C_NACKPositionConfig(port, I2C_NACKPosition_Current);
+//    dbg_printf("%2d SR2 SR1 = %08" PRIx32 "\n", dbg_counter, I2C_GetLastEvent(port));
+
+        I2C_GenerateSTART(port, ENABLE);
+
+//    dbg_printf("%2d SR2 SR1 = %08" PRIx32 "\n", dbg_counter, I2C_GetLastEvent(port));
+
+        /* I2C_EVENT_MASTER_MODE_SELECT = BUSY, MSL and SB flag */
+        if (!i2c_wait_for_event(port, I2C_EVENT_MASTER_MODE_SELECT, timeout)) {
+            dbg_printf("Failed while waiting for I2C_EVENT_MASTER_MODE_SELECT\n");
+            return false;
+        }
+
+        I2C_Send7bitAddress(port, address, I2C_Direction_Receiver);
+
+        // I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED == BUSY, MSL and ADDR
+        if (!i2c_wait_for_event(port, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED, timeout)) {
+            dbg_printf("Failed while waiting for I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED\n");
+            return false;
+        }
+    }
+
+    if (count == 1) {
+        I2C_AcknowledgeConfig(port, DISABLE);
+
+        __disable_irq();
+        (void) port->SR2;
+        I2C_GenerateSTOP(port, ENABLE);
+        __enable_irq();
+
+        while (!I2C_CheckEvent(port, I2C_EVENT_MASTER_BYTE_RECEIVED)) {
+            __NOP();
+        }
+
+        *buf = I2C_ReceiveData(port);
+    } else if (count == 2) {
+        I2C_NACKPositionConfig(port, I2C_NACKPosition_Next);
+
+        __disable_irq();
+        (void) port->SR2;
+        I2C_AcknowledgeConfig(port, DISABLE);
+        __enable_irq();
+
+        while (!I2C_CheckEvent(port, I2C_EVENT_MASTER_BYTE_RECEIVED)) {
+            __NOP();
+        }
+
+        __disable_irq();
+        I2C_GenerateSTOP(port, ENABLE);
+        *buf++ = I2C_ReceiveData(port);
+        __enable_irq();
+        *buf = I2C_ReceiveData(port);
+    } else {
+        do {
+            if (!i2c_wait_for_event(port, I2C_EVENT_MASTER_BYTE_RECEIVED, timeout)) {
+                dbg_printf("Failed while waiting for I2C_EVENT_MASTER_BYTE_RECEIVED, count=%d\n", count);
+                return false;
+            }
+
+            *buf++ = I2C_ReceiveData(port);
+        } while (--count != 2);
+
+        I2C_AcknowledgeConfig(port, DISABLE);
+
+        __disable_irq();
+        *buf++ = I2C_ReceiveData(port);
+        I2C_GenerateSTOP(port, ENABLE);
+        __enable_irq();
+
+        *buf++ = I2C_ReceiveData(port);
+
+        if (!i2c_wait_for_event(port, I2C_EVENT_MASTER_BYTE_RECEIVED, timeout)) {
+            dbg_printf("Failed while waiting for I2C_EVENT_MASTER_BYTE_RECEIVED\n");
+            return false;
+        }
+
+        *buf = I2C_ReceiveData(port);
+    }
+
+    while (I2C_GetFlagStatus(port, I2C_FLAG_STOPF)) {
+        __NOP();
+    }
+
+    return true;
+}
+
+int main() {
+    SystemInit();
+
+    init_printf(nullptr, dbg_putc);
+
+    dbg_printf("i2c1\n");
+
+    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO
+                           | RCC_APB2Periph_USART1
+                           | RCC_APB2Periph_GPIOA
+                           | RCC_APB2Periph_GPIOB
+                           | RCC_APB2Periph_GPIOC,
+                           ENABLE);
+
+    /* ***************************************** */
+
+    // Debug on port B
+
+    RCC_APB2PeriphResetCmd(RCC_APB2Periph_GPIOB, ENABLE);
+    RCC_APB2PeriphResetCmd(RCC_APB2Periph_GPIOB, DISABLE);
+
+    // Make Port B's pin #5 the debug output pin
+    GPIO_InitTypeDef init;
+    GPIO_StructInit(&init);
+    init.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
+    init.GPIO_Mode = GPIO_Mode_Out_PP;
+    init.GPIO_Speed = GPIO_Speed_2MHz;
+    GPIO_Init(GPIOB, &init);
+
+    /* ***************************************** */
+
+    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2,
+                           ENABLE);
+
+    /*
+     * PB10 I2C2_SCL
+     * PB11 I2C2_SDA
+     */
+
+    RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C2, ENABLE);
+    RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C2, DISABLE);
+
+    GPIO_StructInit(&init);
+    init.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;
+    init.GPIO_Mode = GPIO_Mode_AF_OD;
+    GPIO_Init(GPIOB, &init);
+
+    /*
+    i2c2->CR2 |= 36; // APB1 freq is 36 MHz
+    // 36 MHz = 27.78 ns, 400 kHz = 2500ns
+    // 2500 ns / 27.78 ns = 89.99
+    i2c2->CCR |= I2C_CCR_FS | 90;
+    */
+
+    I2C_TypeDef *const i2c_port = I2C2;
+    I2C_DeInit(i2c_port);
+    I2C_InitTypeDef i2c_init;
+    I2C_StructInit(&i2c_init);
+    i2c_init.I2C_ClockSpeed = 100 * 1000;
+    i2c_init.I2C_Ack = I2C_Ack_Enable;
+    i2c_init.I2C_Mode = I2C_Mode_I2C;
+    I2C_Init(i2c_port, &i2c_init);
+    I2C_Cmd(i2c_port, ENABLE);
+
+    const int DS3231_address = 0b11010000; // 0x68
+
+    run = true;
+    bool toggle = true;
+    bool success = true;
+    while (run) {
+        GPIO_WriteBit(GPIOB, GPIO_Pin_5, toggle ? Bit_SET : Bit_RESET);
+        GPIO_WriteBit(GPIOB, GPIO_Pin_6, toggle ? Bit_SET : Bit_RESET);
+        GPIO_WriteBit(GPIOB, GPIO_Pin_7, toggle ? Bit_SET : Bit_RESET);
+        toggle = !toggle;
+
+        if (!success) {
+            dbg_printf("resetting...\n");
+            i2c_hard_reset(i2c_port, i2c_init);
+        }
+
+        uint8_t buf[12];
+        for (size_t i = 0; i < SizeOfArray(buf); i++) {
+            buf[i] = 0;
+        }
+
+        success = i2c_write(i2c_port, DS3231_address, buf, 1, false);
+
+        if (!success) {
+            dbg_printf("i2c_write failed\n");
+            continue;
+        }
+
+        success = i2c_read(i2c_port, DS3231_address, buf, SizeOfArray<uint8_t>(buf), false);
+
+        if (success) {
+            dbg_printf(
+                "%3d %3d %3d %3d %3d %3d %3d %3d %3d %3d %3d %3d\n"
+//                "%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x" /*" %02x %02x %02x %02x"*/ "\n"
+                    "\n",
+//                buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7], buf[8],
+//                buf[9], buf[10], buf[11], buf[12], buf[13], buf[14], buf[15],
+                buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7], buf[8],
+                buf[9], buf[10], buf[11]/*, buf[12], buf[13], buf[14], buf[15]*/);
+        }
+    }
+
+    return 0;
+}
+