/**
	*****************************************************************************
	* @file     cmem7_uart.c
	*
	* @brief    CMEM7 uart file
	*
	*
	* @version  V1.0
	* @date     3. September 2013
	*
	* @note               
	*           
	*****************************************************************************
	* @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, CAPITAL-MICRO 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.
	*
	* <h2><center>&copy; COPYRIGHT 2013 Capital-micro </center></h2>
	*****************************************************************************
	*/

#include "cmem7_uart.h"

#define UART_Mode_8b                        1
#define UART_Mode_8b_Parity                 7

#define UART_BaudMode_0                     0
#define UART_BaudMode_1                     1
#define UART_BaudMode_Division							19200

#define UART_WR_MAX_FIFO_SIZE               16	

static uint32_t UART_GetClock(UART0_Type* UARTx) {
	uint32_t dividor;

	if ((uint32_t)UARTx == (uint32_t)UART0) {
		dividor = GLOBAL_CTRL->CLK_SEL_0_b.UART0_CLK;
	} else if ((uint32_t)UARTx == (uint32_t)UART1) {
		dividor = GLOBAL_CTRL->CLK_SEL_0_b.UART1_CLK;
	} else if ((uint32_t)UARTx == (uint32_t)UART2) {
		dividor = GLOBAL_CTRL->CLK_SEL_1_b.UART2_CLK;
	}
	
	return SYSTEM_CLOCK_FREQ / (1 << (dividor + 1));
}

static uint16_t UART_CalcBaudrateReload(uint32_t FreqHz, uint32_t Baudrate) {
  if (Baudrate <= UART_BaudMode_Division) {                     
		/** reload in mode 0
		  *    reload = FreqHz / 16 * Baudrate
		  * round up 
		  *    reload = FreqHz / 16 * Baudrate + 1/ 2
		  *    reload = (2 * FreqHz + 16 * Baudrate) / 2 * 16 * Baudrate
		  */
		return ((FreqHz << 1) + (Baudrate << 4)) / (Baudrate << 5);
	} 
	
	/** reload in mode 1
		*    reload = Baudrate * 16 * 65536 / FreqHz
		* round up 
		*    reload = Baudrate * 16 * 65536 / FreqHz + 1/ 2
		*    reload = (2 * Baudrate * 16 * 65536 + FreqHz) / 2 * FreqHz
		*/
	return ((((uint64_t)(Baudrate)) << 21) + FreqHz) / (FreqHz << 1);
}
            
void UART_Init(UART0_Type* UARTx, UART_InitTypeDef *init) {
 	assert_param(IS_UART_ALL_PERIPH(UARTx));
	assert_param(init);
 	assert_param(IS_UART_STOPBITS(init->UART_StopBits));
 	assert_param(IS_UART_PARITY(init->UART_Parity));
	
	/* TODO : assume clock is 50MHz */
	UARTx->BAUDRATE = UART_CalcBaudrateReload(
	  UART_GetClock(UARTx), init->UART_BaudRate);
	UARTx->CTRL_b.MODE = 
	  (init->UART_Parity == UART_Parity_None) ? 
	  UART_Mode_8b : UART_Mode_8b_Parity;	
	UARTx->CTRL_b.STOP = init->UART_StopBits;
	UARTx->CTRL_b.PARITY = 
	  (init->UART_Parity == UART_Parity_None) ? 
	  UART_Parity_Even : init->UART_Parity;
	UARTx->CTRL_b.LOOPBACK = init->UART_LoopBack;
	UARTx->CTRL_b.RX_EN = init->UART_RxEn;
	UARTx->CTRL_b.CTS = init->UART_CtsEn;
	UARTx->CTRL_b.BAUD_MODE = 
	  (init->UART_BaudRate > UART_BaudMode_Division) ? 
	  UART_BaudMode_1 : UART_BaudMode_0;
	UARTx->CTRL_b.FIFO_EN = TRUE;
	UARTx->CTRL_b.RX_THRESHOLD = UART_WR_MAX_FIFO_SIZE;
	UARTx->CTRL_b.RX_HALF_FULL = (UART_WR_MAX_FIFO_SIZE >> 1);
	UARTx->TIMEOUT = 0xFF;
	
	UARTx->INT_MASK |= UART_Int_All;
	UARTx->INT_SEEN &= UART_Int_All;
}

void UART_EnableInt(UART0_Type* UARTx, uint32_t Int, BOOL enable) {
	assert_param(IS_UART_ALL_PERIPH(UARTx));
	assert_param(IS_UART_INT(Int));
	
  if (enable) {
	  UARTx->INT_MASK &= ~Int;
	} else {
		UARTx->INT_MASK |= Int;
	}
	
	UARTx->INT_MASK &= UART_Int_All;
}

void UART_Enable(UART0_Type* UARTx, BOOL enable) {
	assert_param(IS_UART_ALL_PERIPH(UARTx));
	
	UARTx->RUN_b.EN = enable;
}

BOOL UART_GetIntStatus(UART0_Type* UARTx, uint32_t Int) {
	assert_param(IS_UART_ALL_PERIPH(UARTx));
	assert_param(IS_UART_INT(Int));
	
	if (0 != (UARTx->INT_SEEN & Int)) {
		return TRUE;
	}
	
	return FALSE;
}

void UART_ClearInt(UART0_Type* UARTx, uint32_t Int) {
	assert_param(IS_UART_ALL_PERIPH(UARTx));
	assert_param(IS_UART_INT(Int));
	
	UARTx->INT_SEEN = Int;
}

uint8_t UART_Write(UART0_Type* UARTx, uint8_t Size, uint8_t* Data) {
	uint8_t count;
	
	/* Check the parameters */
  assert_param(IS_UART_ALL_PERIPH(UARTx));
	assert_param(Data);
	
	if (!UARTx->RUN_b.EN) {
		return 0;
	}
	
	count = 0;
	while (!UARTx->STATUS_b.TF && count < Size) {
		UARTx->TX_BUF = *(Data + count++);
	}
  
	return count;
}

/* return value is actual read data size */
uint8_t UART_Read(UART0_Type* UARTx, uint8_t Size, uint8_t* Data) {
	uint8_t count;
	
	assert_param(IS_UART_ALL_PERIPH(UARTx));
	assert_param(Data);
	
	if (!UARTx->RUN_b.EN) {
		return 0;
	}
	
	count = 0;
	while (UARTx->STATUS_b.RNE && count < Size) {
		*(Data + count++) = (UARTx->RX_BUF & 0x00FF);
	}
	
	return count;	
}