rt-thread-official/bsp/efm32/drv_acmp.c

/***************************************************************************//**
 * @file    drv_acmp.c
 * @brief   ACMP (analog comparator) driver of RT-Thread RTOS for EFM32
 *  COPYRIGHT (C) 2012, RT-Thread Development Team
 * @author  onelife
 * @version 1.0
 *******************************************************************************
 * @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
 * 2011-06-17   onelife     Modify init and control function for efm32lib v2
 *  upgrading
 ******************************************************************************/

/***************************************************************************//**
 * @addtogroup efm32
 * @{
 ******************************************************************************/

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

#if (defined(RT_USING_ACMP0) || defined(RT_USING_ACMP1))
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
#ifdef RT_ACMP_DEBUG
#define acmp_debug(format,args...) 			rt_kprintf(format, ##args)
#else
#define acmp_debug(format,args...)
#endif

/* 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_Disable(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;
			struct efm32_acmp_control_t *control;

			control = (struct efm32_acmp_control_t *)args;
			acmp_debug("ACMP: control -> init start\n");

			/* 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 the specified ACMP unit
 *
 * @details
 *
 * @note
 *
 * @param[in] device
 *	Pointer to device descriptor
 *
 * @param[in] unitNumber
 *	Unit number
 *
 * @return
 *	Pointer to ACMP device
 ******************************************************************************/
static struct efm32_acmp_device_t *rt_hw_acmp_unit_init(
	rt_device_t device,
	rt_uint8_t 	unitNumber)
{
	struct efm32_acmp_device_t 		*acmp;
	efm32_irq_hook_init_t			hook;
	CMU_Clock_TypeDef				acmpClock;

	do
	{
		/* Allocate device */
		acmp = rt_malloc(sizeof(struct efm32_acmp_device_t));
		if (acmp == RT_NULL)
		{
			acmp_debug("ACMP err: no mem for ACMP%d\n", unitNumber);
			break;
		}

		/* Initialization */
		if (unitNumber >= ACMP_COUNT)
		{
			break;
		}
		switch (unitNumber)
		{
		case 0:
			acmp->acmp_device	= ACMP0;
			acmpClock 			= (CMU_Clock_TypeDef)cmuClock_ACMP0;
			break;

		case 1:
			acmp->acmp_device	= ACMP1;
			acmpClock 			= (CMU_Clock_TypeDef)cmuClock_ACMP1;
			break;

		default:
			break;
		}

		/* Enable ACMP clock */
		CMU_ClockEnable(acmpClock, true);

		/* Reset */
		ACMP_Reset(acmp->acmp_device);

		/* Config interrupt and NVIC */
		hook.type			= efm32_irq_type_acmp;
		hook.unit			= unitNumber;
		hook.cbFunc 		= rt_hw_acmp_isr;
		hook.userPtr		= device;
		efm32_irq_hook_register(&hook);

		return acmp;
	} while(0);

	if (acmp)
	{
		rt_free(acmp);
	}
	rt_kprintf("ACMP: Init failed!\n");
	return RT_NULL;
}

/***************************************************************************//**
 * @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;

#ifdef RT_USING_ACMP0
	if ((acmp = rt_hw_acmp_unit_init(&acmp0_device, 0)) != RT_NULL)
	{
		rt_hw_acmp_register(&acmp0_device, RT_ACMP0_NAME, EFM32_NO_DATA, acmp);
	}
#endif

#ifdef RT_USING_ACMP1
	if ((acmp = rt_hw_acmp_unit_init(&acmp1_device, 1)) != RT_NULL)
	{
		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;
	}
}

#endif
/***************************************************************************//**
 * @}
 ******************************************************************************/