From 5af248eaefd0a7ea8a8d9cc9e929fbc8dd45d616 Mon Sep 17 00:00:00 2001
From: meepingsnesroms <guicrith@gmail.com>
Date: Sat, 24 Aug 2019 12:56:18 -0700
Subject: [PATCH] Partially implement TSC2101 buffer

---
 bugs/unimplementedHardware.txt |  3 +++
 src/tsc2101.c                  | 42 ++++++++++++++++++++++++++++++----
 2 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/bugs/unimplementedHardware.txt b/bugs/unimplementedHardware.txt
index f55f6d8..cb87ced 100644
--- a/bugs/unimplementedHardware.txt
+++ b/bugs/unimplementedHardware.txt
@@ -39,6 +39,9 @@ electrical noise on lines(conversions probably should have +-20 added to values)
 in the edge case that SPICLK2 is disabled while using ADS7846 and a 1 was the last bit shifted out 0s will still be shifted in
 need to to verify behavior of differential mode bit
 
+TSC2101:
+values of AUX1 and AUX2 are unknown an need to be tested, emulation has issues with the USB port shortly after and it would make sense that since the T3 has the same connector as the m515 AUX1 is the device type resistor in the bottom connector
+
 SD Card:
 block specific write protect bits don't work
 IRQ2 may actually be attached to the SD Card data out pin, triggering an interrupt when a 0 is received to process the return data
diff --git a/src/tsc2101.c b/src/tsc2101.c
index 8e24265..f3fd297 100644
--- a/src/tsc2101.c
+++ b/src/tsc2101.c
@@ -37,13 +37,17 @@ enum{
    TOUCH_CONTROL_AUX2_MAX,
    TOUCH_CONTROL_AUX2_MIN,
    TOUCH_CONTROL_MEASUREMENT_CONFIGURATION,
-   TOUCH_CONTROL_PROGRAMMABLE_DELAY
+   TOUCH_CONTROL_PROGRAMMABLE_DELAY,
    //TOUCH_CONTROL_RESERVED_X...
    //TODO: add audio control registers
+   BUFFER_START = TSC2101_REG_LOCATION(3, 0),
+   BUFFER_END = TSC2101_REG_LOCATION(3, 63)
 };
 
 
 static uint16_t tsc2101Registers[0x100];
+static uint8_t  tsc2101BufferReadPosition;
+static uint8_t  tsc2101BufferWritePosition;
 static uint16_t tsc2101CurrentWord;
 static uint8_t  tsc2101CurrentWordBitsRemaining;
 static uint8_t  tsc2101CurrentPage;
@@ -53,6 +57,31 @@ static bool     tsc2101Read;
 static bool     tsc2101ChipSelect;
 
 
+static uint8_t tsc2101BufferFifoEntrys(void){
+   //check for wraparound
+   if(tsc2101BufferWritePosition < tsc2101BufferReadPosition)
+      return tsc2101BufferWritePosition + 17 - tsc2101BufferReadPosition;
+   return tsc2101BufferWritePosition - tsc2101BufferReadPosition;
+}
+
+static uint16_t tsc2101BufferFifoRead(void){
+   if(tsc2101BufferFifoEntrys() > 0)
+      tsc2101BufferReadPosition = (tsc2101BufferReadPosition + 1) % 65;
+   return tsc2101Registers[BUFFER_START + tsc2101BufferReadPosition];
+}
+
+static void tsc2101BufferFifoWrite(uint16_t value){
+   if(tsc2101BufferFifoEntrys() < 64)
+      tsc2101BufferWritePosition = (tsc2101BufferWritePosition + 1) % 65;
+   else
+      debugLog("tsc2101 buffer FIFO overflowed\n");
+   tsc2101Registers[BUFFER_START + tsc2101BufferWritePosition] = value;
+}
+
+static void tsc2101BufferFifoFlush(void){
+   tsc2101BufferReadPosition = tsc2101BufferWritePosition;
+}
+
 static uint16_t tsc2101GetAnalogMask(void){
    const uint16_t masks[4] = {0xFFF, 0xFF0, 0xFFC, 0xFFF};
 
@@ -108,7 +137,6 @@ static void tsc2101ResetRegisters(void){
 
    //TODO: need to add all the registers here
    tsc2101Registers[TOUCH_CONTROL_STATUS] = 0x8000;
-   //tsc2101Registers[TOUCH_CONTROL_BUFFER_MODE] = 0x0200;//TODO: return buffer emupt flag based on real buffer size
    tsc2101Registers[TOUCH_CONTROL_REFERENCE] = 0x0002;
 
    tsc2101RefreshInterrupt();
@@ -126,9 +154,13 @@ static uint16_t tsc2101RegisterRead(uint8_t page, uint8_t address){
          debugLog("TSC2101 read status register\n");
          return tsc2101Registers[TOUCH_CONTROL_STATUS] | 0x0FDE;
 
+      case TOUCH_CONTROL_BUFFER_MODE:
+         return tsc2101Registers[TOUCH_CONTROL_BUFFER_MODE] | (tsc2101BufferFifoEntrys() == 64) << 10 | (tsc2101BufferFifoEntrys() == 0) << 9;
+
       case TOUCH_CONTROL_RESET_CONTROL_REGISTER:
          return 0xFFFF;
 
+      //TOUCH_DATA_* registers are scaned, the values get copyed to the register when the result is generated
       case TOUCH_DATA_X:
       case TOUCH_DATA_Y:
       case TOUCH_DATA_Z1:
@@ -138,8 +170,8 @@ static uint16_t tsc2101RegisterRead(uint8_t page, uint8_t address){
       case TOUCH_DATA_AUX2:
       case TOUCH_DATA_TEMP1:
       case TOUCH_DATA_TEMP2:
-         debugLog("Unimplemented TSC2101 analog port read:%d\n", combinedRegisterNumber);
-         return 0x0000;
+         //simple read, no actions needed
+         return tsc2101Registers[combinedRegisterNumber];
 
       default:
          debugLog("Unimplemented TSC2101 register read, page:0x%01X, address:0x%02X\n", page, address);
@@ -212,6 +244,8 @@ static void tsc2101RegisterWrite(uint8_t page, uint8_t address, uint16_t value){
 }
 
 void tsc2101Reset(bool isBoot){
+   tsc2101BufferReadPosition = 0;
+   tsc2101BufferWritePosition = 0;
    tsc2101CurrentWord = 0x0000;
    tsc2101CurrentWordBitsRemaining = 16;
    tsc2101CurrentPage = 0;