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More accurate I2C handling

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I still need to document this; GPIOs are wierd with their tristate behavior
This commit is contained in:
Pokechu22 2022-08-09 12:15:38 -07:00
parent 0f4dd969bb
commit 25e31d121b
1 changed files with 17 additions and 9 deletions
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26
Source/Core/Core/HW/WII_IPC.cpp
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@ -11,6 +11,7 @@
#include "Common/Logging/Log.h"
#include "Core/Core.h"
#include "Core/CoreTiming.h"
#include "Core/Debugger/Debugger_SymbolMap.h"
#include "Core/HW/DVD/DVDInterface.h"
#include "Core/HW/MMIO.h"
#include "Core/HW/ProcessorInterface.h"
@ -257,6 +258,7 @@ static u32 ReadGPIOIn(Core::System& system)
gpio_in[GPIO::AVE_SDA] = false; // pull low
else
gpio_in[GPIO::AVE_SDA] = true; // passive pullup
gpio_in[GPIO::AVE_SCL] = true; // passive pullup
return gpio_in.m_hex;
}
@ -267,7 +269,7 @@ u32 WiiIPC::GetGPIOOut()
// In practice this means that (at least for the AVE I²C pins) a 1 is output when the pin is an
// input. (RVLoader depends on this.)
// https://github.com/Aurelio92/RVLoader/blob/75732f248019f589deb1109bba7b5323a8afaadf/source/i2c.c#L101-L109
return m_gpio_out.m_hex | ~m_gpio_dir.m_hex;
return (m_gpio_out.m_hex | ~(m_gpio_dir.m_hex)) & (ReadGPIOIn(m_system) | m_gpio_dir.m_hex);
}
void WiiIPC::GPIOOutChanged(u32 old_value_hex)
@ -275,22 +277,25 @@ void WiiIPC::GPIOOutChanged(u32 old_value_hex)
Common::Flags<GPIO> old_value;
old_value.m_hex = old_value_hex;
if (m_gpio_out[GPIO::DO_EJECT])
Common::Flags<GPIO> new_value;
new_value.m_hex = GetGPIOOut();
if (new_value[GPIO::DO_EJECT])
{
INFO_LOG_FMT(WII_IPC, "Ejecting disc due to GPIO write");
m_system.GetDVDInterface().EjectDisc(Core::CPUThreadGuard{m_system}, DVD::EjectCause::Software);
}
// I²C logic for the audio/video encoder (AVE)
if (m_gpio_dir[GPIO::AVE_SCL])
if (true || m_gpio_dir[GPIO::AVE_SCL])
{
if (old_value[GPIO::AVE_SCL] && m_gpio_out[GPIO::AVE_SCL])
if (old_value[GPIO::AVE_SCL] && new_value[GPIO::AVE_SCL])
{
// Check for changes to SDA while the clock is high. This only makes sense if the SDA pin is
// outbound.
if (m_gpio_dir[GPIO::AVE_SDA])
if (true || m_gpio_dir[GPIO::AVE_SDA])
{
if (old_value[GPIO::AVE_SDA] && !m_gpio_out[GPIO::AVE_SDA])
if (old_value[GPIO::AVE_SDA] && !new_value[GPIO::AVE_SDA])
{
DEBUG_LOG_FMT(WII_IPC, "AVE: Start I2C");
// SDA falling edge (now pulled low) while SCL is high indicates I²C start
@ -301,7 +306,7 @@ void WiiIPC::GPIOOutChanged(u32 old_value_hex)
i2c_state.is_correct_i2c_address = false;
i2c_state.read_ave_address = false;
}
else if (!old_value[GPIO::AVE_SDA] && m_gpio_out[GPIO::AVE_SDA])
else if (!old_value[GPIO::AVE_SDA] && new_value[GPIO::AVE_SDA])
{
DEBUG_LOG_FMT(WII_IPC, "AVE: Stop I2C");
// SDA rising edge (now passive pullup) while SCL is high indicates I²C stop
@ -310,7 +315,7 @@ void WiiIPC::GPIOOutChanged(u32 old_value_hex)
}
}
}
else if (!old_value[GPIO::AVE_SCL] && m_gpio_out[GPIO::AVE_SCL])
else if (!old_value[GPIO::AVE_SCL] && new_value[GPIO::AVE_SCL])
{
// Clock changed from low to high; transfer a new bit.
if (i2c_state.active && (!i2c_state.read_i2c_address || i2c_state.is_correct_i2c_address))
@ -327,7 +332,7 @@ void WiiIPC::GPIOOutChanged(u32 old_value_hex)
if (i2c_state.bit_counter < 8)
{
i2c_state.current_byte <<= 1;
if (m_gpio_out[GPIO::AVE_SDA])
if (new_value[GPIO::AVE_SDA])
i2c_state.current_byte |= 1;
}
@ -347,6 +352,9 @@ void WiiIPC::GPIOOutChanged(u32 old_value_hex)
else
{
WARN_LOG_FMT(WII_IPC, "AVE: Wrong I2C address: {:02x}", i2c_state.current_byte >> 1);
Dolphin_Debugger::PrintCallstack(Core::CPUThreadGuard(m_system),
Common::Log::LogType::WII_IPC,
Common::Log::LogLevel::LINFO);
i2c_state.acknowledge = false;
i2c_state.is_correct_i2c_address = false;
}