/******************************************************************//**
 * @file 		drv_acmp.c
 * @brief 	ACMP (analog comparator) driver of RT-Thread RTOS for EFM32
 * 	COPYRIGHT (C) 2011, RT-Thread Development Team
 * @author 	onelife
 * @version 	0.4 beta
 **********************************************************************
 * @section License
 * The license and distribution terms for this file may be found in the file LICENSE in this 
 * distribution or at http://www.rt-thread.org/license/LICENSE
 **********************************************************************
 * @section Change Logs
 * Date			Author		Notes
 * 2011-02-21	onelife		Initial creation for EFM32
 *********************************************************************/
 
/******************************************************************//**
* @addtogroup efm32
* @{
*********************************************************************/

/* Includes -------------------------------------------------------------------*/
#include "board.h"
#include "drv_acmp.h"

/* Private typedef -------------------------------------------------------------*/
/* Private define --------------------------------------------------------------*/
/* Private macro --------------------------------------------------------------*/
/* Private variables ------------------------------------------------------------*/
#ifdef RT_USING_ACMP0
	static struct rt_device acmp0_device;
#endif

#ifdef RT_USING_ACMP1
	static struct rt_device acmp1_device;
#endif

/* Private function prototypes ---------------------------------------------------*/
ACMP_WarmTime_TypeDef efm32_acmp_WarmTimeCalc(rt_uint32_t hfperFreq);

/* Private functions ------------------------------------------------------------*/
/******************************************************************//**
 * @brief
 *   Initialize ACMP device
 *
 * @details
 *
 * @note
 *
 * @param[in] dev
 *   Pointer to device descriptor
 *
 * @return
 *   Error code
 *********************************************************************/
 static rt_err_t rt_acmp_init(rt_device_t dev)
{
	RT_ASSERT(dev != RT_NULL);

	struct efm32_acmp_device_t *acmp;

	acmp = (struct efm32_acmp_device_t *)(dev->user_data);

	acmp->hook.cbFunc 	= RT_NULL;
	acmp->hook.userPtr 	= RT_NULL;

	return RT_EOK;
}

/******************************************************************//**
* @brief
*	Configure ACMP device
*
* @details
*
* @note
*
* @param[in] dev
*	Pointer to device descriptor
*
* @param[in] cmd
*	ACMP control command
*
* @param[in] args
*	Arguments
*
* @return
*	Error code
*********************************************************************/
static rt_err_t rt_acmp_control(
	rt_device_t 	dev, 
	rt_uint8_t 		cmd, 
	void 			*args)
{
	RT_ASSERT(dev != RT_NULL);

	struct efm32_acmp_device_t *acmp;

	acmp = (struct efm32_acmp_device_t *)(dev->user_data);

	switch (cmd)
	{
	case RT_DEVICE_CTRL_SUSPEND:
		/* Suspend device */
		dev->flag |= RT_DEVICE_FLAG_SUSPENDED;
		ACMP_DisableNoReset(acmp->acmp_device);
		break;

	case RT_DEVICE_CTRL_RESUME:
		/* Resume device */
		dev->flag &= ~RT_DEVICE_FLAG_SUSPENDED;
		ACMP_Enable(acmp->acmp_device);
		break;

	case RT_DEVICE_CTRL_ACMP_INIT:
		{
			rt_bool_t int_en = false;

			rt_kprintf("ACMP: control -> init start\n");
			/* change device setting */
			struct efm32_acmp_control_t *control;

			control = (struct efm32_acmp_control_t *)args;

			/* Configure ACMPn */
			if (control->init == RT_NULL) 
			{
				return -RT_ERROR;
			}
			ACMP_Init(acmp->acmp_device, control->init);
			ACMP_ChannelSet(acmp->acmp_device, control->negInput, control->posInput);
			if (control->output != RT_NULL)
			{
				ACMP_GPIOSetup(
					acmp->acmp_device, 
					control->output->location, 
					control->output->enable, 
					control->output->invert);
				int_en = true;
			}
			if (control->hook.cbFunc != RT_NULL)
			{
				acmp->hook.cbFunc = control->hook.cbFunc;
				acmp->hook.userPtr = control->hook.userPtr;
				int_en = true;
			}

			if (int_en)
			{
				/* Enable edge interrupt */
				ACMP_IntEnable(acmp->acmp_device, ACMP_IEN_EDGE);
				ACMP_IntClear(acmp->acmp_device, ACMP_IFC_EDGE);
				
				/* Enable ACMP0/1 interrupt vector in NVIC */
				NVIC_ClearPendingIRQ(ACMP0_IRQn);
				NVIC_SetPriority(ACMP0_IRQn, EFM32_IRQ_PRI_DEFAULT);
				NVIC_EnableIRQ(ACMP0_IRQn);
			}
		}
		break;

	case RT_DEVICE_CTRL_ACMP_OUTPUT:
		*((rt_bool_t *)args) = \
			(acmp->acmp_device->STATUS & ACMP_STATUS_ACMPOUT) ? true : false;
		break;
		
		default:
			return -RT_ERROR;
	}

	return RT_EOK;
}

/******************************************************************//**
* @brief
*	Register ACMP device
*
* @details
*
* @note
*
* @param[in] device
*	Pointer to device descriptor
*
* @param[in] name
*	Device name
*
* @param[in] flag
*	Configuration flags
*
* @param[in] acmp
*	Pointer to ACMP device descriptor 
*
* @return
*	Error code
*********************************************************************/
rt_err_t rt_hw_acmp_register(
	rt_device_t		device, 
	const char		*name, 
	rt_uint32_t		flag, 
	struct efm32_acmp_device_t *acmp)
{
	RT_ASSERT(device != RT_NULL);

	device->type 		= RT_Device_Class_Char; /* fixme: should be acmp type */
	device->rx_indicate = RT_NULL;
	device->tx_complete = RT_NULL;
	device->init 		= rt_acmp_init;
	device->open		= RT_NULL;
	device->close		= RT_NULL;
	device->read 		= RT_NULL;
	device->write 		= RT_NULL;
	device->control 	= rt_acmp_control;
	device->user_data	= acmp;

	/* register a character device */
	return rt_device_register(device, name, flag);
}

/******************************************************************//**
 * @brief
 *	ACMP edge trigger interrupt handler
 *
 * @details
 *
 * @note
 *********************************************************************/
void rt_hw_acmp_isr(rt_device_t dev)
{
	RT_ASSERT(dev != RT_NULL);

	struct efm32_acmp_device_t *acmp;

	acmp = (struct efm32_acmp_device_t *)(dev->user_data);

	if (acmp->hook.cbFunc != RT_NULL)
	{
		(acmp->hook.cbFunc)(acmp->hook.userPtr);
	}
}

/******************************************************************//**
* @brief
*	Initialize all ACMP module related hardware and register ACMP device to kernel
*
* @details
*
* @note
*
*********************************************************************/
void rt_hw_acmp_init(void)
{
	struct efm32_acmp_device_t 	*acmp;
	efm32_irq_hook_init_t		hook;

#ifdef RT_USING_ACMP0
	acmp = rt_malloc(sizeof(struct efm32_acmp_device_t));
	if (acmp == RT_NULL)
	{
		rt_kprintf("no memory for ACMP0 driver\n");
		return;
	}
	acmp->acmp_device		= ACMP0;

	/* Enable clock for ACMP0 module */
	CMU_ClockEnable(cmuClock_ACMP0, true);

	/* Reset */
	 ACMP_Reset(ACMP0);

	hook.type			= efm32_irq_type_acmp;
	hook.unit			= 0;
	hook.cbFunc 		= rt_hw_acmp_isr;
	hook.userPtr		= &acmp0_device;
	efm32_irq_hook_register(&hook);

	rt_hw_acmp_register(&acmp0_device, RT_ACMP0_NAME, EFM32_NO_DATA, acmp);	
#endif

#ifdef RT_USING_ACMP1
	acmp = rt_malloc(sizeof(struct efm32_acmp_device_t));
	if (acmp == RT_NULL)
	{
		rt_kprintf("no memory for ACMP1 driver\n");
		return;
	}
	acmp->acmp_device		= ACMP1;

	/* Enable clock for ACMP1 module */
	CMU_ClockEnable(cmuClock_ACMP1, true);

	/* Reset */
	 ACMP_Reset(ACMP1);

	hook.type			= efm32_irq_type_acmp;
	hook.unit			= 0;
	hook.cbFunc 		= rt_hw_acmp_isr;
	hook.userPtr		= &acmp0_device;
	efm32_irq_hook_register(&hook);

	rt_hw_acmp_register(&acmp1_device, RT_ACMP1_NAME, EFM32_NO_DATA, acmp);	
#endif

}

/******************************************************************//**
 * @brief
 *    Calculate the warm-up time value providing at least 10us
 *
 * @param[in] hfperFreq 
 *    Frequency in Hz of reference HFPER clock. Set to 0 to use currently defined HFPER clock 
 *    setting
 *
 * @return
 *   Warm-up time  value to use for ACMP in order to achieve at least 10us
 *********************************************************************/
ACMP_WarmTime_TypeDef efm32_acmp_WarmTimeCalc(rt_uint32_t hfperFreq)
{
	if (!hfperFreq)
	{
		hfperFreq = CMU_ClockFreqGet(cmuClock_HFPER);

		/* Just in case, make sure we get non-zero freq for below calculation */
		if (!hfperFreq)
		{
		  hfperFreq = 1;
		}
	}

	/* Determine number of HFPERCLK cycle >= 10us */
	if (4 * 1000000 / hfperFreq > 10)
	{
		return acmpWarmTime4;
	}
	else if (8 * 1000000 / hfperFreq > 10)
	{
		return acmpWarmTime8;
	}
	else if (16 * 1000000 / hfperFreq > 10)
	{
		return acmpWarmTime16;
	}
	else if (32 * 1000000 / hfperFreq > 10)
	{
		return acmpWarmTime32;
	}
	else if (64 * 1000000 / hfperFreq > 10)
	{
		return acmpWarmTime64;
	}
	else if (128 * 1000000 / hfperFreq > 10)
	{
		return acmpWarmTime128;
	}
	else if (256 * 1000000 / hfperFreq > 10)
	{
		return acmpWarmTime256;
	}
	else if (512 * 1000000 / hfperFreq > 10)
	{
		return acmpWarmTime512;
	}
}

/******************************************************************//**
 * @}
*********************************************************************/