Allow rebooting on Brahma 2

source/i2c.c

@@ -0,0 +1,150 @@
+#include "i2c.h"
+#include "draw.h"
+
+//-----------------------------------------------------------------------------
+
+static const struct { u8 bus_id, reg_addr } dev_data[] = {
+    {0, 0x4A}, {0, 0x7A}, {0, 0x78},
+    {1, 0x4A}, {1, 0x78}, {1, 0x2C},
+    {1, 0x2E}, {1, 0x40}, {1, 0x44},
+    {2, 0xD6}, {2, 0xD0}, {2, 0xD2},
+    {2, 0xA4}, {2, 0x9A}, {2, 0xA0},
+};
+
+const inline u8 i2cGetDeviceBusId(u8 device_id) {
+    return dev_data[device_id].bus_id;
+}
+
+const inline u8 i2cGetDeviceRegAddr(u8 device_id) {
+    return dev_data[device_id].reg_addr;
+}
+
+//-----------------------------------------------------------------------------
+
+static vu8* const reg_data_addrs[] = {
+    (vu8*)(I2C1_REG_OFF + I2C_REG_DATA),
+    (vu8*)(I2C2_REG_OFF + I2C_REG_DATA),
+    (vu8*)(I2C3_REG_OFF + I2C_REG_DATA),
+};
+
+inline vu8* const i2cGetDataReg(u8 bus_id) {
+    return reg_data_addrs[bus_id];
+}
+
+//-----------------------------------------------------------------------------
+
+static vu8* const reg_cnt_addrs[] = {
+    (vu8*)(I2C1_REG_OFF + I2C_REG_CNT),
+    (vu8*)(I2C2_REG_OFF + I2C_REG_CNT),
+    (vu8*)(I2C3_REG_OFF + I2C_REG_CNT),
+};
+
+inline vu8* const i2cGetCntReg(u8 bus_id) {
+    return reg_cnt_addrs[bus_id];
+}
+
+//-----------------------------------------------------------------------------
+
+inline void i2cWaitBusy(u8 bus_id) {
+    while (*i2cGetCntReg(bus_id) & 0x80);
+}
+
+inline bool i2cGetResult(u8 bus_id) {
+    i2cWaitBusy(bus_id);
+    return (*i2cGetCntReg(bus_id) >> 4) & 1;
+}
+
+void i2cStop(u8 bus_id, u8 arg0) {
+    *i2cGetCntReg(bus_id) = (arg0 << 5) | 0xC0;
+    i2cWaitBusy(bus_id);
+    *i2cGetCntReg(bus_id) = 0xC5;
+}
+
+//-----------------------------------------------------------------------------
+
+bool i2cSelectDevice(u8 bus_id, u8 dev_reg) {
+    i2cWaitBusy(bus_id);
+    *i2cGetDataReg(bus_id) = dev_reg;
+    *i2cGetCntReg(bus_id) = 0xC2;
+    return i2cGetResult(bus_id);
+}
+
+bool i2cSelectRegister(u8 bus_id, u8 reg) {
+    i2cWaitBusy(bus_id);
+    *i2cGetDataReg(bus_id) = reg;
+    *i2cGetCntReg(bus_id) = 0xC0;
+    return i2cGetResult(bus_id);
+}
+
+//-----------------------------------------------------------------------------
+
+u8 i2cReadRegister(u8 dev_id, u8 reg) {
+    u8 bus_id = i2cGetDeviceBusId(dev_id);
+    u8 dev_addr = i2cGetDeviceRegAddr(dev_id);
+
+    for (size_t i = 0; i < 8; i++) {
+        if (i2cSelectDevice(bus_id, dev_addr) && i2cSelectRegister(bus_id, reg)) {
+            if (i2cSelectDevice(bus_id, dev_addr | 1)) {
+                i2cWaitBusy(bus_id);
+                i2cStop(bus_id, 1);
+                i2cWaitBusy(bus_id);
+                return *i2cGetDataReg(bus_id);
+            }
+        }
+        *i2cGetCntReg(bus_id) = 0xC5;
+        i2cWaitBusy(bus_id);
+    }
+    return 0xff;
+}
+
+bool i2cReadRegisterBuffer(unsigned int dev_id, int reg, u8* buffer, size_t buf_size) {
+    u8 bus_id = i2cGetDeviceBusId(dev_id);
+    u8 dev_addr = i2cGetDeviceRegAddr(dev_id);
+
+    size_t j = 0;
+    while (!i2cSelectDevice(bus_id, dev_addr)
+        || !i2cSelectRegister(bus_id, reg)
+        || !i2cSelectDevice(bus_id, dev_addr | 1))
+    {
+        i2cWaitBusy(bus_id);
+        *i2cGetCntReg(bus_id) = 0xC5;
+        i2cWaitBusy(bus_id);
+        if (++j >= 8)
+            return false;
+    }
+
+    if (buf_size != 1) {
+        for (int i = 0; i < buf_size - 1; i++) {
+            i2cWaitBusy(bus_id);
+            *i2cGetCntReg(bus_id) = 0xF0;
+            i2cWaitBusy(bus_id);
+            buffer[i] = *i2cGetDataReg(bus_id);
+        }
+    }
+
+    i2cWaitBusy(bus_id);
+    *i2cGetCntReg(bus_id) = 0xE1;
+    i2cWaitBusy(bus_id);
+    *buffer = *i2cGetDataReg(bus_id);
+    return true;
+}
+
+bool i2cWriteRegister(u8 dev_id, u8 reg, u8 data) {
+    u8 bus_id = i2cGetDeviceBusId(dev_id);
+    u8 dev_addr = i2cGetDeviceRegAddr(dev_id);
+
+    for (int i = 0; i < 8; i++) {
+        if (i2cSelectDevice(bus_id, dev_addr) && i2cSelectRegister(bus_id, reg)) {
+            i2cWaitBusy(bus_id);
+            *i2cGetDataReg(bus_id) = data;
+            *i2cGetCntReg(bus_id) = 0xC1;
+            i2cStop(bus_id, 0);
+            if (i2cGetResult(bus_id))
+                return true;
+        }
+        *i2cGetCntReg(bus_id) = 0xC5;
+        i2cWaitBusy(bus_id);
+    }
+
+    return false;
+}

source/i2c.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include "common.h"
+
+#define I2C1_REG_OFF 0x10161000
+#define I2C2_REG_OFF 0x10144000
+#define I2C3_REG_OFF 0x10148000
+
+#define I2C_REG_DATA  0
+#define I2C_REG_CNT   1
+#define I2C_REG_CNTEX 2
+#define I2C_REG_SCL   4
+
+#define I2C_DEV_MCU  3
+#define I2C_DEV_GYRO 10
+#define I2C_DEV_IR   13
+
+const u8 i2cGetDeviceBusId(u8 device_id);
+const u8 i2cGetDeviceRegAddr(u8 device_id);
+
+vu8* const i2cGetDataReg(u8 bus_id);
+vu8* const i2cGetCntReg(u8 bus_id);
+
+void i2cWaitBusy(u8 bus_id);
+bool i2cGetResult(u8 bus_id);
+u8 i2cGetData(u8 bus_id);
+void i2cStop(u8 bus_id, u8 arg0);
+
+bool i2cSelectDevice(u8 bus_id, u8 dev_reg);
+bool i2cSelectRegister(u8 bus_id, u8 reg);
+
+u8 i2cReadRegister(u8 dev_id, u8 reg);
+bool i2cWriteRegister(u8 dev_id, u8 reg, u8 data);
+
+bool i2cReadRegisterBuffer(unsigned int dev_id, int reg, u8* buffer, size_t buf_size);

source/main.c

@@ -4,6 +4,7 @@
 
 #include "draw.h"
 #include "hid.h"
+#include "i2c.h"
 #include "fatfs/ff.h"
 #include "gamecart/protocol.h"
 #include "gamecart/command_ctr.h"
@@ -26,6 +27,12 @@ static void wait_key(void) {
     InputWait();
 }
 
+void Reboot()
+{
+    i2cWriteRegister(I2C_DEV_MCU, 0x20, 1 << 2);
+    while(true);
+}
+
 struct Context {
     u8* buffer;
     size_t buffer_size;
@@ -187,5 +194,6 @@ restart_prompt:
     if (!(InputWait() & BUTTON_B))
         goto restart_program;
 
+    Reboot();
     return 0;
 }