/**
  ******************************************************************************
  * @file    stm32l1xx_dac.c
  * @author  MCD Application Team
  * @version V1.1.0
  * @date    24-January-2012
  * @brief   This file provides firmware functions to manage the following 
  *          functionalities of the Digital-to-Analog Converter (DAC) peripheral: 
  *          + DAC channels configuration: trigger, output buffer, data format
  *          + DMA management      
  *          + Interrupts and flags management

  * @verbatim      
  *   
 ===============================================================================
                        ##### DAC Peripheral features #####
 ===============================================================================
    [..] The device integrates two 12-bit Digital Analog Converters that can 
         be used independently or simultaneously (dual mode):
         (#) DAC channel1 with DAC_OUT1 (PA4) as output.
         (#) DAC channel2 with DAC_OUT2 (PA5) as output.
  
    [..] Digital to Analog conversion can be non-triggered using DAC_Trigger_None
         and DAC_OUT1/DAC_OUT2 is available once writing to DHRx register using 
         DAC_SetChannel1Data()/DAC_SetChannel2Data.
  
    [..] Digital to Analog conversion can be triggered by:
         (#) External event: EXTI Line 9 (any GPIOx_Pin9) using DAC_Trigger_Ext_IT9.
             The used pin (GPIOx_Pin9) must be configured in input mode.
         (#) Timers TRGO: TIM2, TIM4, TIM6, TIM7 and TIM9 
             (DAC_Trigger_T2_TRGO, DAC_Trigger_T4_TRGO...).
             The timer TRGO event should be selected using TIM_SelectOutputTrigger()
         (#) Software using DAC_Trigger_Software.
  
    [..] Each DAC channel integrates an output buffer that can be used to 
         reduce the output impedance, and to drive external loads directly
         without having to add an external operational amplifier.
         To enable, the output buffer use  
         DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
            
    [..] Refer to the device datasheet for more details about output impedance
         value with and without output buffer.
  
    [..] Both DAC channels can be used to generate:
         (#) Noise wave using DAC_WaveGeneration_Noise
         (#) Triangle wave using DAC_WaveGeneration_Triangle
  
    [..] Wave generation can be disabled using DAC_WaveGeneration_None.
  
    [..] The DAC data format can be:
         (#) 8-bit right alignment using DAC_Align_8b_R
         (#) 12-bit left alignment using DAC_Align_12b_L
         (#) 12-bit right alignment using DAC_Align_12b_R
  
    [..] The analog output voltage on each DAC channel pin is determined
         by the following equation: DAC_OUTx = VREF+ * DOR / 4095
         with  DOR is the Data Output Register.
         VEF+ is the input voltage reference (refer to the device datasheet)
         e.g. To set DAC_OUT1 to 0.7V, use
         DAC_SetChannel1Data(DAC_Align_12b_R, 868);
         Assuming that VREF+ = 3.3, DAC_OUT1 = (3.3 * 868) / 4095 = 0.7V.
  
    [..] A DMA1 request can be generated when an external trigger (but not
         a software trigger) occurs if DMA1 requests are enabled using
         DAC_DMACmd()
    [..] DMA1 requests are mapped as following:
         (#) DAC channel1 is mapped on DMA1 channel3 which must be already 
             configured.
         (#) DAC channel2 is mapped on DMA1 channel4 which must be already 
             configured.
  
                      ##### How to use this driver #####
 ===============================================================================
    [..]
        (+) DAC APB clock must be enabled to get write access to DAC registers using
            RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE)
        (+) Configure DAC_OUTx (DAC_OUT1: PA4, DAC_OUT2: PA5) in analog mode.
        (+) Configure the DAC channel using DAC_Init()
        (+) Enable the DAC channel using DAC_Cmd()

   @endverbatim
  *    
  ******************************************************************************
  * @attention
  *
  * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
  * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
  * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
  * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
  * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
  * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
  *
  * FOR MORE INFORMATION PLEASE READ CAREFULLY THE LICENSE AGREEMENT FILE
  * LOCATED IN THE ROOT DIRECTORY OF THIS FIRMWARE PACKAGE.
  *
  * <h2><center>&copy; COPYRIGHT 2012 STMicroelectronics</center></h2>
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "stm32l1xx_dac.h"
#include "stm32l1xx_rcc.h"

/** @addtogroup STM32L1xx_StdPeriph_Driver
  * @{
  */

/** @defgroup DAC 
  * @brief DAC driver modules
  * @{
  */ 

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* CR register Mask */
#define CR_CLEAR_MASK              ((uint32_t)0x00000FFE)

/* DAC Dual Channels SWTRIG masks */
#define DUAL_SWTRIG_SET            ((uint32_t)0x00000003)
#define DUAL_SWTRIG_RESET          ((uint32_t)0xFFFFFFFC)

/* DHR registers offsets */
#define DHR12R1_OFFSET             ((uint32_t)0x00000008)
#define DHR12R2_OFFSET             ((uint32_t)0x00000014)
#define DHR12RD_OFFSET             ((uint32_t)0x00000020)

/* DOR register offset */
#define DOR_OFFSET                 ((uint32_t)0x0000002C)

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/

/** @defgroup DAC_Private_Functions
  * @{
  */ 

/** @defgroup DAC_Group1 DAC channels configuration
 *  @brief   DAC channels configuration: trigger, output buffer, data format.
 *
@verbatim
 ===============================================================================
  ##### DAC channels configuration: trigger, output buffer, data format #####
 ===============================================================================

@endverbatim
  * @{
  */

/**
  * @brief  Deinitializes the DAC peripheral registers to their default reset values.
  * @param  None
  * @retval None
  */
void DAC_DeInit(void)
{
  /* Enable DAC reset state */
  RCC_APB1PeriphResetCmd(RCC_APB1Periph_DAC, ENABLE);
  /* Release DAC from reset state */
  RCC_APB1PeriphResetCmd(RCC_APB1Periph_DAC, DISABLE);
}

/**
  * @brief  Initializes the DAC peripheral according to the specified 
  *         parameters in the DAC_InitStruct.
  * @param  DAC_Channel: the selected DAC channel.
  *   This parameter can be one of the following values:
  *     @arg DAC_Channel_1: DAC Channel1 selected.
  *     @arg DAC_Channel_2: DAC Channel2 selected.
  * @param  DAC_InitStruct: pointer to a DAC_InitTypeDef structure that
  *         contains the configuration information for the specified DAC channel.
  * @retval None
  */
void DAC_Init(uint32_t DAC_Channel, DAC_InitTypeDef* DAC_InitStruct)
{
  uint32_t tmpreg1 = 0, tmpreg2 = 0;

  /* Check the DAC parameters */
  assert_param(IS_DAC_CHANNEL(DAC_Channel));
  assert_param(IS_DAC_TRIGGER(DAC_InitStruct->DAC_Trigger));
  assert_param(IS_DAC_GENERATE_WAVE(DAC_InitStruct->DAC_WaveGeneration));
  assert_param(IS_DAC_LFSR_UNMASK_TRIANGLE_AMPLITUDE(DAC_InitStruct->DAC_LFSRUnmask_TriangleAmplitude));
  assert_param(IS_DAC_OUTPUT_BUFFER_STATE(DAC_InitStruct->DAC_OutputBuffer));

/*---------------------------- DAC CR Configuration --------------------------*/
  /* Get the DAC CR value */
  tmpreg1 = DAC->CR;
  /* Clear BOFFx, TENx, TSELx, WAVEx and MAMPx bits */
  tmpreg1 &= ~(CR_CLEAR_MASK << DAC_Channel);
  /* Configure for the selected DAC channel: buffer output, trigger, wave generation,
     mask/amplitude for wave generation */
  /* Set TSELx and TENx bits according to DAC_Trigger value */
  /* Set WAVEx bits according to DAC_WaveGeneration value */
  /* Set MAMPx bits according to DAC_LFSRUnmask_TriangleAmplitude value */ 
  /* Set BOFFx bit according to DAC_OutputBuffer value */   
  tmpreg2 = (DAC_InitStruct->DAC_Trigger | DAC_InitStruct->DAC_WaveGeneration |
             DAC_InitStruct->DAC_LFSRUnmask_TriangleAmplitude | DAC_InitStruct->DAC_OutputBuffer);
  /* Calculate CR register value depending on DAC_Channel */
  tmpreg1 |= tmpreg2 << DAC_Channel;
  /* Write to DAC CR */
  DAC->CR = tmpreg1;
}

/**
  * @brief  Fills each DAC_InitStruct member with its default value.
  * @param  DAC_InitStruct: pointer to a DAC_InitTypeDef structure which will 
  *         be initialized.
  * @retval None
  */
void DAC_StructInit(DAC_InitTypeDef* DAC_InitStruct)
{
/*--------------- Reset DAC init structure parameters values -----------------*/
  /* Initialize the DAC_Trigger member */
  DAC_InitStruct->DAC_Trigger = DAC_Trigger_None;
  /* Initialize the DAC_WaveGeneration member */
  DAC_InitStruct->DAC_WaveGeneration = DAC_WaveGeneration_None;
  /* Initialize the DAC_LFSRUnmask_TriangleAmplitude member */
  DAC_InitStruct->DAC_LFSRUnmask_TriangleAmplitude = DAC_LFSRUnmask_Bit0;
  /* Initialize the DAC_OutputBuffer member */
  DAC_InitStruct->DAC_OutputBuffer = DAC_OutputBuffer_Enable;
}

/**
  * @brief  Enables or disables the specified DAC channel.
  * @param  DAC_Channel: The selected DAC channel. 
  *   This parameter can be one of the following values:
  *     @arg DAC_Channel_1: DAC Channel1 selected
  *     @arg DAC_Channel_2: DAC Channel2 selected
  * @param  NewState: new state of the DAC channel. 
  *      This parameter can be: ENABLE or DISABLE.
  * @note When the DAC channel is enabled the trigger source can no more
  *       be modified.
  * @retval None
  */
void DAC_Cmd(uint32_t DAC_Channel, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_DAC_CHANNEL(DAC_Channel));
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable the selected DAC channel */
    DAC->CR |= (DAC_CR_EN1 << DAC_Channel);
  }
  else
  {
    /* Disable the selected DAC channel */
    DAC->CR &= (~(DAC_CR_EN1 << DAC_Channel));
  }
}

/**
  * @brief  Enables or disables the selected DAC channel software trigger.
  * @param  DAC_Channel: the selected DAC channel.
  *   This parameter can be one of the following values:
  *     @arg DAC_Channel_1: DAC Channel1 selected
  *     @arg DAC_Channel_2: DAC Channel2 selected
  * @param  NewState: new state of the selected DAC channel software trigger.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void DAC_SoftwareTriggerCmd(uint32_t DAC_Channel, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_DAC_CHANNEL(DAC_Channel));
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable software trigger for the selected DAC channel */
    DAC->SWTRIGR |= (uint32_t)DAC_SWTRIGR_SWTRIG1 << (DAC_Channel >> 4);
  }
  else
  {
    /* Disable software trigger for the selected DAC channel */
    DAC->SWTRIGR &= ~((uint32_t)DAC_SWTRIGR_SWTRIG1 << (DAC_Channel >> 4));
  }
}

/**
  * @brief  Enables or disables simultaneously the two DAC channels software
  *         triggers.
  * @param  NewState: new state of the DAC channels software triggers.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void DAC_DualSoftwareTriggerCmd(FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable software trigger for both DAC channels */
    DAC->SWTRIGR |= DUAL_SWTRIG_SET;
  }
  else
  {
    /* Disable software trigger for both DAC channels */
    DAC->SWTRIGR &= DUAL_SWTRIG_RESET;
  }
}

/**
  * @brief  Enables or disables the selected DAC channel wave generation.
  * @param  DAC_Channel: the selected DAC channel.
  *   This parameter can be one of the following values:
  *     @arg DAC_Channel_1: DAC Channel1 selected
  *     @arg DAC_Channel_2: DAC Channel2 selected
  * @param  DAC_Wave: Specifies the wave type to enable or disable.
  *   This parameter can be one of the following values:
  *     @arg DAC_Wave_Noise: noise wave generation
  *     @arg DAC_Wave_Triangle: triangle wave generation
  * @param  NewState: new state of the selected DAC channel wave generation.
  *   This parameter can be: ENABLE or DISABLE.
  * @note   
  * @retval None
  */
void DAC_WaveGenerationCmd(uint32_t DAC_Channel, uint32_t DAC_Wave, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_DAC_CHANNEL(DAC_Channel));
  assert_param(IS_DAC_WAVE(DAC_Wave)); 
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable the selected wave generation for the selected DAC channel */
    DAC->CR |= DAC_Wave << DAC_Channel;
  }
  else
  {
    /* Disable the selected wave generation for the selected DAC channel */
    DAC->CR &= ~(DAC_Wave << DAC_Channel);
  }
}

/**
  * @brief  Set the specified data holding register value for DAC channel1.
  * @param  DAC_Align: Specifies the data alignment for DAC channel1.
  *   This parameter can be one of the following values: