From 3bbffa65a13826515eb8384d72e25fad9910a544 Mon Sep 17 00:00:00 2001
From: meepingsnesroms <guicrith@gmail.com>
Date: Tue, 19 Jun 2018 14:38:49 -0700
Subject: [PATCH] Can now run with or without the bootloader in the Qt port

Also clean up ads7846 functions
---
 qtBuildSystem/Mu/emuwrapper.cpp    |  6 +++++-
 src/ads7846.c                      | 31 +++++++++++++++++-------------
 src/ads7846.h                      |  4 ++--
 src/hardwareRegistersAccessors.c.h |  4 ++--
 4 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/qtBuildSystem/Mu/emuwrapper.cpp b/qtBuildSystem/Mu/emuwrapper.cpp
index 654f878..0328444 100644
--- a/qtBuildSystem/Mu/emuwrapper.cpp
+++ b/qtBuildSystem/Mu/emuwrapper.cpp
@@ -129,7 +129,7 @@ uint32_t EmuWrapper::init(QString romPath, QString bootloaderPath, uint32_t feat
          return EMU_ERROR_INVALID_PARAMETER;
       }
 
-      if(bootloaderPath != ""){
+      if(bootloaderPath != "" && bootloaderFile.exists()){
          if(bootloaderFile.open(QFile::ReadOnly)){
             bootloaderData = bootloaderFile.readAll();
             bootloaderFile.close();
@@ -141,6 +141,10 @@ uint32_t EmuWrapper::init(QString romPath, QString bootloaderPath, uint32_t feat
             return EMU_ERROR_INVALID_PARAMETER;
          }
       }
+      else{
+         bootloaderBuff.data = NULL;
+         bootloaderBuff.size = 0;
+      }
 
       error = emulatorInit(romBuff, bootloaderBuff, features);
       if(error == EMU_ERROR_NONE){
diff --git a/src/ads7846.c b/src/ads7846.c
index 30fcfe9..32dfb26 100644
--- a/src/ads7846.c
+++ b/src/ads7846.c
@@ -10,21 +10,29 @@ bool     ads7846PenIrqEnabled;
 uint16_t ads7846OutputValue;
 
 
-void ads7846SendBit(bool bit){
+static inline bool ads7846GetAdcBit(){
+   //a new control byte can be sent while receiving data
+   //this is valid behavior as long as the start of the last control byte was 16 or more clock cycles ago
+   bool bit = ads7846OutputValue & 0x8000;
+   ads7846OutputValue <<= 1;
+   return bit;
+}
+
+bool ads7846ExchangeBit(bool bitIn){
    if(ads7846BitsToNextControl > 0)
       ads7846BitsToNextControl--;
 
    if(ads7846BitsToNextControl == 0){
       //check for control bit
-      if(bit){
+      if(bitIn){
          ads7846ControlByte = 0x01;
          ads7846BitsToNextControl = 16;
       }
-      return;
+      return ads7846GetAdcBit();
    }
    else if(ads7846BitsToNextControl < 8){
       ads7846ControlByte <<= 1;
-      ads7846ControlByte |= bit;
+      ads7846ControlByte |= bitIn;
    }
 
    if(ads7846BitsToNextControl == 7){
@@ -103,17 +111,14 @@ void ads7846SendBit(bool bit){
          }
       }
    }
+
+   return ads7846GetAdcBit();
 }
 
-bool ads7846RecieveBit(){
-   bool bit;
-
-   //a new control byte can be sent while receiving data
-   //this is valid behavior as long as there has been 16 clock cycles since the start of the last control byte
-
-   bit = ads7846OutputValue & 0x8000;
-   ads7846OutputValue <<= 1;
-   return bit;
+bool ads7846Busy(){
+   if(ads7846BitsToNextControl == 8)
+      return true;
+   return false;
 }
 
 void ads7846Reset(){
diff --git a/src/ads7846.h b/src/ads7846.h
index 3daf20f..f0b5d99 100644
--- a/src/ads7846.h
+++ b/src/ads7846.h
@@ -7,7 +7,7 @@ extern uint8_t  ads7846ControlByte;
 extern bool     ads7846PenIrqEnabled;
 extern uint16_t ads7846OutputValue;
 
-void ads7846SendBit(bool bit);
-bool ads7846RecieveBit();
+bool ads7846ExchangeBit(bool bitIn);
+bool ads7846Busy();
 
 void ads7846Reset();
diff --git a/src/hardwareRegistersAccessors.c.h b/src/hardwareRegistersAccessors.c.h
index fb7536b..400ec94 100644
--- a/src/hardwareRegistersAccessors.c.h
+++ b/src/hardwareRegistersAccessors.c.h
@@ -250,9 +250,9 @@ static inline void setSpiCont2(uint16_t value){
 
       for(uint8_t bits = 0; bits < bitCount; bits++){
          //the Palm m515 seems to invert received bits
-         ads7846SendBit(spi2Data & 0x8000);
+         bool newBit = ads7846ExchangeBit(spi2Data & 0x8000);
          spi2Data <<= 1;
-         spi2Data |= !ads7846RecieveBit();
+         spi2Data |= !newBit;
       }
       registerArrayWrite16(SPIDATA2, spi2Data);