From 1396d24f579fbf52ec9166ca0a3f1d8edab6cdfd Mon Sep 17 00:00:00 2001
From: id101010 <aaron@duckpond.ch>
Date: Wed, 13 May 2015 01:34:26 +0200
Subject: [PATCH] Working touchcontroller communication

---
 discovery/src/ll_touch.c | 134 ++++++++++++---------------------------
 1 file changed, 42 insertions(+), 92 deletions(-)

diff --git a/discovery/src/ll_touch.c b/discovery/src/ll_touch.c
index 0b98c21..7192661 100644
--- a/discovery/src/ll_touch.c
+++ b/discovery/src/ll_touch.c
@@ -2,73 +2,9 @@
 #include<stm32f4xx_spi.h>
 #include<stm32f4xx_rcc.h>
 
-
 #define CLEAR_CS    GPIO_ResetBits(GPIOB,GPIO_Pin_9)
 #define SET_CS      GPIO_SetBits(GPIOB,GPIO_Pin_9)
 
-
-/*
-static void touch_read(const uint16_t RegisterStartAddress, const uint8_t NumberOfRegisters, uint16_t *DataBuffer, const uint16_t OffsetInBuffer)
-{
-  uint16_t ControlValue;
-  uint8_t i,j, RegisterIndex;
-  uint16_t InputValue;
-  
-  ControlValue = 0xE400 | (RegisterStartAddress & 0x03FF);                          // Create the 16-bit header
-  
-  for (i=0;i<100;i++);                                                              // delay
-
-  //Write out the control word
-  CLEAR_CS;
-  SPI_I2S_SendData(SPI1, ControlValue);
-  while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) != RESET);  
-  while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
-  InputValue = SPI_I2S_ReceiveData(SPI1);                                           // Read dummy
-
-  //Copy each register in the buffer contiguously.
-  //Read data in.
-  for (RegisterIndex=0; RegisterIndex<NumberOfRegisters; RegisterIndex++){
-    SPI_I2S_SendData(SPI1, 0xFFFF);
-    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) != RESET); 
-    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
-    InputValue = SPI_I2S_ReceiveData(SPI1);                                         // read data
-    *(DataBuffer+OffsetInBuffer+RegisterIndex)=(uint16_t)InputValue;
-  }
-
-  SET_CS;
-  for (j=0;j<5;j++);                                                                // delay
-}
-
-static void touch_send_cmd(const uint16_t RegisterAddress, const uint8_t NumberOfRegisters, uint16_t *DataBuffer, const uint8_t OffsetInBuffer)
-{
-  uint16_t ControlValue;
-  uint16_t ValueToWrite;
-  uint16_t RegisterIndex;
-  uint8_t j;
-  
-  ControlValue = 0xE000 | (RegisterAddress & 0x03FF);                               //Create the 16-bit header
-
-  //Write out the control word
-  CLEAR_CS;
-  SPI_I2S_SendData(SPI1, ControlValue);
-  while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) != RESET);  
-  while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
-
-  //And then the data
-  for (RegisterIndex=0; RegisterIndex<NumberOfRegisters; RegisterIndex++){
-    ValueToWrite= *(DataBuffer+RegisterIndex+OffsetInBuffer);
-    SPI_I2S_SendData(SPI1, ValueToWrite);
-    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) != RESET); 
-    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
-  }
-
-  SET_CS;
-  for (j=0;j<5;j++);                                                                // delay
-}
-
-
-*/
-
 static uint8_t touch_send(uint8_t dat)
 {
   SPI_I2S_SendData(SPI2, dat);
@@ -77,59 +13,74 @@ static uint8_t touch_send(uint8_t dat)
   return  SPI_I2S_ReceiveData(SPI2);                                    
 }
 
-
 bool ll_touch_init() 
 {
     //We have a ADS7843 Touch controller
     //Datasheet: http://www.ti.com/lit/ds/symlink/ads7843.pdf
 
-    return false; //TODO: remove
-
     // init structures
     SPI_InitTypeDef     SPI_SPI2_InitStructure;
     GPIO_InitTypeDef    GPIO_SPI2_InitStructure;
 
-    // enable gpio clock    TODO: Check if not done already
-    //RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
-    // enable spi clock     TODO: Check if this is the correct one
-    //RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
+    // enable gpio clock
+    RCC_APB2PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
+    
+    // enable spi clock 
+    RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);
 
-    GPIO_SPI2_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_14 | GPIO_Pin_15;     // 10 = SPI2_SCK, 14 = SPI2_MISO, 15 = SPI2_MOSI
-    GPIO_SPI2_InitStructure.GPIO_OType = GPIO_OType_OD;
-    GPIO_SPI2_InitStructure.GPIO_Mode = GPIO_Mode_AF;
-    GPIO_SPI2_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
+    // fill gpio init struct and init gpio
+    GPIO_StructInit(&GPIO_SPI2_InitStructure);
+    GPIO_SPI2_InitStructure.GPIO_Pin    = GPIO_Pin_10 | GPIO_Pin_14 | GPIO_Pin_15;     // 10 = SPI2_SCK, 14 = SPI2_MISO, 15 = SPI2_MOSI
+    GPIO_SPI2_InitStructure.GPIO_OType  = GPIO_OType_PP;
+    GPIO_SPI2_InitStructure.GPIO_Mode   = GPIO_Mode_AF;
+    GPIO_SPI2_InitStructure.GPIO_Speed  = GPIO_Speed_50MHz;
+    GPIO_SPI2_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
+    GPIO_Init(GPIOB, &GPIO_SPI2_InitStructure);
+    
+    // set chip select
+    SET_CS;
+
+    // fill gpio init struct and init gpio
+    GPIO_StructInit(&GPIO_SPI2_InitStructure);
+    GPIO_SPI2_InitStructure.GPIO_Pin    = GPIO_Pin_9;                                  // 9 = SPI2_CS
+    GPIO_SPI2_InitStructure.GPIO_Mode   = GPIO_Mode_OUT;
+    GPIO_SPI2_InitStructure.GPIO_OType  = GPIO_OType_PP;
+    GPIO_SPI2_InitStructure.GPIO_Speed  = GPIO_Speed_50MHz;
     GPIO_Init(GPIOB, &GPIO_SPI2_InitStructure);
 
-    GPIO_SPI2_InitStructure.GPIO_Pin = GPIO_Pin_9;                                  // 9 = SPI2_CS
-    GPIO_SPI2_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
-    GPIO_SPI2_InitStructure.GPIO_OType = GPIO_OType_PP;
-    GPIO_SPI2_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
-    GPIO_Init(GPIOB, &GPIO_SPI2_InitStructure);
+    // init alternate functions on GPIOB
+    GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_SPI2);
+    GPIO_PinAFConfig(GPIOB, GPIO_PinSource14, GPIO_AF_SPI2);
+    GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_SPI2);
 
     // clear spi initialisation
     SPI_I2S_DeInit(SPI2);
 
     // fill spi init structure
-    SPI_SPI2_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
-    SPI_SPI2_InitStructure.SPI_Mode = SPI_Mode_Master;
-    SPI_SPI2_InitStructure.SPI_DataSize = SPI_DataSize_8b;
-    SPI_SPI2_InitStructure.SPI_CPOL = SPI_CPOL_Low;
-    SPI_SPI2_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
-    SPI_SPI2_InitStructure.SPI_NSS = SPI_NSS_Soft;
-    SPI_SPI2_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;
-    SPI_SPI2_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
-    //SPI_SPI2_InitStructure.SPI_CRCPolynomial = 7;  
+    SPI_StructInit(&SPI_SPI2_InitStructure);
+    SPI_SPI2_InitStructure.SPI_Direction            = SPI_Direction_2Lines_FullDuplex;
+    SPI_SPI2_InitStructure.SPI_Mode                 = SPI_Mode_Master;
+    SPI_SPI2_InitStructure.SPI_DataSize             = SPI_DataSize_8b;
+    SPI_SPI2_InitStructure.SPI_CPOL                 = SPI_CPOL_Low;
+    SPI_SPI2_InitStructure.SPI_CPHA                 = SPI_CPHA_1Edge;
+    SPI_SPI2_InitStructure.SPI_NSS                  = SPI_NSS_Soft | SPI_NSSInternalSoft_Set;
+    SPI_SPI2_InitStructure.SPI_BaudRatePrescaler    = SPI_BaudRatePrescaler_256;
+    SPI_SPI2_InitStructure.SPI_FirstBit             = SPI_FirstBit_MSB;
 
     // init spi
     SPI_Init(SPI2, &SPI_SPI2_InitStructure);  
+ 
+    // enable spi   
     SPI_Cmd(SPI2, ENABLE);
 
 
+    /*
+     * TEST ahead ...
+     */
 
-
-    //test
     CLEAR_CS;
     touch_send(0x90);
+    
     for(long i=0; i<1000; i++);
 
     uint16_t buf = ((uint16_t) touch_send(0x00))<<5;
@@ -138,7 +89,6 @@ bool ll_touch_init()
     SET_CS;
 
 
-
     return true;
 }