/* include path: install_root/linux/include */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/device.h>
#include <linux/err.h>
#include <asm/uaccess.h>
#include <linux/interrupt.h>
#include <linux/irqreturn.h>
#include <linux/wait.h>

#include "stm32f4xx.h"
#include "stm32f4xx_hal_rcc.h"
#include "stm32f4xx_hal_gpio.h"
#include "stm32f4xx_hal_adc.h"
#include "stm32f4xx_hal_dma.h"
#include "driver.h"
#include "stm32_hal_legacy.h"

static int major = MAJOR_ADC;
static int minor = 0;
//static dev_t devno;
//static struct cdev *adc_cdev = NULL;
//static int count  = 3;
#define NUM_OF_DEVICES	3
//ruct class *my_class = NULL;
//struct device *dev = NULL;

#define DEVNAME "adc"

struct adc_device {
	dev_t devno;
	struct cdev cdev;
	char data[128];
	char name[16];
	IRQn_Type	DMA_IRQn;
} adc_dev[NUM_OF_DEVICES];

uint32_t gAdc1Value[10][4];

static int adc_open(struct inode *inode, struct file *filep);
static int adc_close(struct inode *inode, struct file *filep);
static ssize_t adc_read(struct file *filep, char __user *buf, size_t size, loff_t *offset);
static ssize_t adc_write(struct file *filep, const char __user *buf, size_t size, loff_t *offset);
static int adc_ioctl(struct inode *inode, struct file *filep, unsigned int cmd, unsigned long arg);

static struct file_operations adc_ops = 
{
	.owner = THIS_MODULE,
	.open = adc_open,
	.release = adc_close,
	.read = adc_read,
	.write = adc_write,
	.ioctl = adc_ioctl,
};

static int adc_open(struct inode *inode, struct file *filep)
{
	int imajor,iminor;
	// ADC_HandleTypeDef hadc;
	imajor = MAJOR(inode->i_rdev);
	iminor = MINOR(inode->i_rdev);

	printk("adc open, major %d, minor %d\n", imajor, iminor);
	// if(imajor != MAJOR_ADC)
	// {
	// 	printk("Error: %s %d adc major fail! %d\n",__FILE__,__LINE__,imajor);
	// 	return -1;
	// }
	// switch(iminor)
	// {
	// case 0:
	// 	hadc.Instance = ADC1;
	// 	__HAL_RCC_ADC1_CLK_ENABLE();
	// 	break;
	// case 1:
	// 	hadc.Instance = ADC2;
	// 	__HAL_RCC_ADC2_CLK_ENABLE();
	// 	break;
	// case 2:
	// 	hadc.Instance = ADC3;
	// 	__HAL_RCC_ADC3_CLK_ENABLE();
	// 	break;
	// }
	
	// __HAL_ADC_ENABLE(&hadc);
	return 0;
}

static int adc_close(struct inode *inode, struct file *filep)
{
	int imajor,iminor;
	ADC_HandleTypeDef handle_adc;
	imajor = MAJOR(inode->i_rdev);
	iminor = MINOR(inode->i_rdev);
	if(imajor != MAJOR_ADC)
	{
		printk("Error: %s %d adc major fail! %d\n",__FILE__,__LINE__,imajor);
		return -1;
	}
	switch(iminor)
	{
	case 0:
		handle_adc.Instance = ADC1;
		__HAL_RCC_ADC1_CLK_DISABLE();
		break;
	case 1:
		handle_adc.Instance = ADC2;
		__HAL_RCC_ADC1_CLK_DISABLE();
		break;
	case 2:
		handle_adc.Instance = ADC3;
		__HAL_RCC_ADC1_CLK_DISABLE();
		break;
	}

	printk("adc close, major %d, minor %d\n", imajor, iminor);
	__HAL_ADC_DISABLE(&handle_adc);
	return 0;
}

static ssize_t adc_read(struct file *filep, char __user *buf, size_t size, loff_t *offset)
{
	//printk("fmc_read!\n");
	return 0;
}

static ssize_t adc_write(struct file *filep, const char __user *buf, size_t size, loff_t *offset)
{
/*	uint32_t i;
	uint8_t	tmp_buf[100];
	printk("fmc_write");
	for(i=0;i<size;i++)
		tmp_buf[i] = *(uint8_t*)(offset+i);
	copy_to_user();*/
	return 0;
}

static int adc_ioctl(struct inode *inode, struct file *filep, unsigned int cmd, unsigned long arg)
{
	int i;	
	// if ( copy_from_user(&fmc_arg, (void*)arg, sizeof(fmc_cpld_t)) )
	// 	return -EFAULT;

	switch(cmd)
	{
		case ADC_GET_RESULT:	
			for(i=0;i<10;i++)
				printk("%d : %#x, %#x, %#x, %#x\n", i, gAdc1Value[i][0], gAdc1Value[i][1], gAdc1Value[i][2], gAdc1Value[i][3]);
		break;
		default:
			printk("Invalid command!\n");
			break;	
	}
	
	return 0;
}

ADC_HandleTypeDef  hadc;
DMA_HandleTypeDef  hdma_adc;
/**
  * @brief  Handles DMA interrupt request.
  * @param  hdma pointer to a DMA_HandleTypeDef structure that contains
  *               the configuration information for the specified DMA Stream.  
  * @retval None
  */
irqreturn_t HAL_DMA_IRQHandler(int irqno, void *dev_id )
{
	uint32_t tmpisr;
	__IO uint32_t count = 0U;
	uint32_t timeout = 18750;	//SystemCoreClock / 9600U;
	DMA_HandleTypeDef *hdma = &hdma_adc;
	/* calculate DMA base and stream number */
	DMA_Base_Registers *regs = (DMA_Base_Registers *)hdma->StreamBaseAddress;

	tmpisr = regs->ISR;

	/* Transfer Error Interrupt management ***************************************/
	if ((tmpisr & (DMA_FLAG_TEIF0_4 << hdma->StreamIndex)) != RESET)
	{
		if(__HAL_DMA_GET_IT_SOURCE(hdma, DMA_IT_TE) != RESET)
		{
			/* Disable the transfer error interrupt */
			hdma->Instance->CR  &= ~(DMA_IT_TE);

			/* Clear the transfer error flag */
			regs->IFCR = DMA_FLAG_TEIF0_4 << hdma->StreamIndex;

			/* Update error code */
			hdma->ErrorCode |= HAL_DMA_ERROR_TE;
		}
	}

	/* FIFO Error Interrupt management ******************************************/
	if ((tmpisr & (DMA_FLAG_FEIF0_4 << hdma->StreamIndex)) != RESET)
	{
		if(__HAL_DMA_GET_IT_SOURCE(hdma, DMA_IT_FE) != RESET)
		{
			/* Clear the FIFO error flag */
			regs->IFCR = DMA_FLAG_FEIF0_4 << hdma->StreamIndex;

			/* Update error code */
			hdma->ErrorCode |= HAL_DMA_ERROR_FE;
		}
	}

	/* Direct Mode Error Interrupt management ***********************************/
	if ((tmpisr & (DMA_FLAG_DMEIF0_4 << hdma->StreamIndex)) != RESET)
	{
		if(__HAL_DMA_GET_IT_SOURCE(hdma, DMA_IT_DME) != RESET)
		{
			/* Clear the direct mode error flag */
			regs->IFCR = DMA_FLAG_DMEIF0_4 << hdma->StreamIndex;

			/* Update error code */
			hdma->ErrorCode |= HAL_DMA_ERROR_DME;
		}
	}

	/* Half Transfer Complete Interrupt management ******************************/
	if ((tmpisr & (DMA_FLAG_HTIF0_4 << hdma->StreamIndex)) != RESET)
	{
		if(__HAL_DMA_GET_IT_SOURCE(hdma, DMA_IT_HT) != RESET)
		{
			/* Clear the half transfer complete flag */
			regs->IFCR = DMA_FLAG_HTIF0_4 << hdma->StreamIndex;

			/* Multi_Buffering mode enabled */
			if(((hdma->Instance->CR) & (uint32_t)(DMA_SxCR_DBM)) != RESET)
			{
				/* Current memory buffer used is Memory 0 */
				if((hdma->Instance->CR & DMA_SxCR_CT) == RESET)
				{
					if(hdma->XferHalfCpltCallback != NULL)
					{
						/* Half transfer callback */
						hdma->XferHalfCpltCallback(hdma);
					}
				}
				/* Current memory buffer used is Memory 1 */
				else
				{
					if(hdma->XferM1HalfCpltCallback != NULL)
					{
						/* Half transfer callback */
						hdma->XferM1HalfCpltCallback(hdma);
					}
				}
			}
			else
			{
				/* Disable the half transfer interrupt if the DMA mode is not CIRCULAR */
				if((hdma->Instance->CR & DMA_SxCR_CIRC) == RESET)
				{
					/* Disable the half transfer interrupt */
					hdma->Instance->CR  &= ~(DMA_IT_HT);
				}

				if(hdma->XferHalfCpltCallback != NULL)
				{
					/* Half transfer callback */
					hdma->XferHalfCpltCallback(hdma);
				}
			}
		}
	}

	/* Transfer Complete Interrupt management ***********************************/
	if ((tmpisr & (DMA_FLAG_TCIF0_4 << hdma->StreamIndex)) != RESET)
	{
		if(__HAL_DMA_GET_IT_SOURCE(hdma, DMA_IT_TC) != RESET)
		{
			/* Clear the transfer complete flag */
			regs->IFCR = DMA_FLAG_TCIF0_4 << hdma->StreamIndex;

			if(HAL_DMA_STATE_ABORT == hdma->State)
			{
				/* Disable all the transfer interrupts */
				hdma->Instance->CR  &= ~(DMA_IT_TC | DMA_IT_TE | DMA_IT_DME);
				hdma->Instance->FCR &= ~(DMA_IT_FE);

				if((hdma->XferHalfCpltCallback != NULL) || (hdma->XferM1HalfCpltCallback != NULL))
				{
					hdma->Instance->CR  &= ~(DMA_IT_HT);
				}

				/* Clear all interrupt flags at correct offset within the register */
				regs->IFCR = 0x3FU << hdma->StreamIndex;

				/* Process Unlocked */
				__HAL_UNLOCK(hdma);

				/* Change the DMA state */
				hdma->State = HAL_DMA_STATE_READY;

				if(hdma->XferAbortCallback != NULL)
				{
					hdma->XferAbortCallback(hdma);
				}
				return IRQ_HANDLED;
			}

			if(((hdma->Instance->CR) & (uint32_t)(DMA_SxCR_DBM)) != RESET)
			{
				/* Current memory buffer used is Memory 0 */
				if((hdma->Instance->CR & DMA_SxCR_CT) == RESET)
				{
					if(hdma->XferM1CpltCallback != NULL)
					{
						/* Transfer complete Callback for memory1 */
						hdma->XferM1CpltCallback(hdma);
					}
				}
				/* Current memory buffer used is Memory 1 */
				else
				{
					if(hdma->XferCpltCallback != NULL)
					{
						/* Transfer complete Callback for memory0 */
						hdma->XferCpltCallback(hdma);
					}
				}
			}
			/* Disable the transfer complete interrupt if the DMA mode is not CIRCULAR */
			else
			{
				if((hdma->Instance->CR & DMA_SxCR_CIRC) == RESET)
				{
					/* Disable the transfer complete interrupt */
					hdma->Instance->CR  &= ~(DMA_IT_TC);

					/* Process Unlocked */
					__HAL_UNLOCK(hdma);

					/* Change the DMA state */
					hdma->State = HAL_DMA_STATE_READY;
				}

				if(hdma->XferCpltCallback != NULL)
				{
					/* Transfer complete callback */
					hdma->XferCpltCallback(hdma);
				}				
			}
		}
	}

	/* manage error case */
	if(hdma->ErrorCode != HAL_DMA_ERROR_NONE)
	{
		if((hdma->ErrorCode & HAL_DMA_ERROR_TE) != RESET)
		{
			hdma->State = HAL_DMA_STATE_ABORT;

			/* Disable the stream */
			__HAL_DMA_DISABLE(hdma);

			do
			{
				if (++count > timeout)
				{
				 	break;
				}
			}
			while((hdma->Instance->CR & DMA_SxCR_EN) != RESET);

			/* Process Unlocked */
			__HAL_UNLOCK(hdma);

			/* Change the DMA state */
			hdma->State = HAL_DMA_STATE_READY;
		}

		if(hdma->XferErrorCallback != NULL)
		{
			/* Transfer error callback */
			hdma->XferErrorCallback(hdma);
		}
	}
	return IRQ_HANDLED;
}
	

int adc_hw_init(void)
{
	ADC_ChannelConfTypeDef sConfig;
	GPIO_InitTypeDef  GPIO_InitStruct;
	/* ADC1 
	 * PA3 - ADC1_IN3
	 * PA4 - ADC1_IN4
	 * PA5 - ADC1_IN5
	 * PA6 - ADC1_IN6
	*/
	__HAL_RCC_GPIOA_CLK_ENABLE();

	GPIO_InitStruct.Pin 	= GPIO_PIN_3 | GPIO_PIN_4 | GPIO_PIN_5 | GPIO_PIN_6;
	GPIO_InitStruct.Mode	= GPIO_MODE_ANALOG;
	GPIO_InitStruct.Pull    = GPIO_NOPULL;
	HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
	
	hadc.Instance          = ADC1;
  
	hadc.Init.ClockPrescaler = ADC_CLOCKPRESCALER_PCLK_DIV2;
	hadc.Init.Resolution = ADC_RESOLUTION_12B;
	hadc.Init.ScanConvMode = ENABLE;
	hadc.Init.ContinuousConvMode = ENABLE;
	hadc.Init.DiscontinuousConvMode = DISABLE;
	hadc.Init.NbrOfDiscConversion = 0;
	//hadc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
	hadc.Init.ExternalTrigConv = ADC_SOFTWARE_START;
	hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT;
	hadc.Init.NbrOfConversion = 4;
	hadc.Init.DMAContinuousRequests = ENABLE;
	hadc.Init.EOCSelection = DISABLE;
      
	if(HAL_ADC_Init(&hadc) != HAL_OK)
	{
		printk(KERN_ERR"adc hw init error!\n");
	}

  	sConfig.SamplingTime = ADC_SAMPLETIME_3CYCLES;
  	sConfig.Offset = 0;
  
  	sConfig.Rank = 1;
  	sConfig.Channel = ADC_CHANNEL_3;
  	if(HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  	{
    	printk(KERN_ERR"adc channel3 init error!\n");
  	}

  	sConfig.Rank = 2;
  	sConfig.Channel = ADC_CHANNEL_4;
  	if(HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  	{
    	printk(KERN_ERR"adc channel4 init error!\n");
  	}

  	sConfig.Rank = 3;
  	sConfig.Channel = ADC_CHANNEL_5;
  	if(HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  	{
    	printk(KERN_ERR"adc channel5 init error!\n");
  	}

  	sConfig.Rank = 4;
  	sConfig.Channel = ADC_CHANNEL_6;
  	if(HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  	{
    	printk(KERN_ERR"adc channel6 init error!\n");
  	}

  	__HAL_RCC_ADC1_CLK_ENABLE();
  	__HAL_ADC_ENABLE(&hadc);

  	// config dma
  	hdma_adc.Instance = DMA2_Stream0;
  
	hdma_adc.Init.Channel  = DMA_CHANNEL_0;
	hdma_adc.Init.Direction = DMA_PERIPH_TO_MEMORY;
	hdma_adc.Init.PeriphInc = DMA_PINC_DISABLE;
	hdma_adc.Init.MemInc = DMA_MINC_ENABLE;
	hdma_adc.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD;
	hdma_adc.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;
	hdma_adc.Init.Mode = DMA_CIRCULAR;
	hdma_adc.Init.Priority = DMA_PRIORITY_HIGH;
	hdma_adc.Init.FIFOMode = DMA_FIFOMODE_DISABLE;         
	hdma_adc.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_HALFFULL;
	hdma_adc.Init.MemBurst = DMA_MBURST_SINGLE;
	hdma_adc.Init.PeriphBurst = DMA_PBURST_SINGLE; 

  	HAL_DMA_Init(&hdma_adc);

  	 /* Associate the initialized DMA handle to the the ADC handle */
	__HAL_LINKDMA(&hadc, DMA_Handle, hdma_adc);

	/*##-4- Configure the NVIC for DMA #########################################*/
	/* NVIC configuration for DMA transfer complete interrupt */
	HAL_NVIC_SetPriority(DMA2_Stream0_IRQn, 3, 0);   
	HAL_NVIC_EnableIRQ(DMA2_Stream0_IRQn);

	return 0;
}

static int __init adc_init(void)
{
	int ret;
	int i;
	printk("adc driver init!\n");

	for (i = 0; i < NUM_OF_DEVICES; i++)
	{
	    adc_dev[i].devno = MKDEV(MAJOR_ADC, i);
		sprintf(adc_dev[i].name, "%s%d", DEVNAME, i+1);
		register_chrdev_region(adc_dev[i].devno, 1, adc_dev[i].name);
		     
		cdev_add(&adc_dev[i].cdev, adc_dev[i].devno, 1);
		cdev_init(&adc_dev[i].cdev, &adc_ops);
	}

	if(adc_hw_init() != 0)
		goto ERR_STEP1;

	adc_dev[0].DMA_IRQn	= DMA2_Stream0_IRQn;
	adc_dev[1].DMA_IRQn	= DMA2_Stream2_IRQn;
	adc_dev[2].DMA_IRQn	= DMA2_Stream1_IRQn;

	// register adc1 interrupt
	ret = request_irq(adc_dev[0].DMA_IRQn, HAL_DMA_IRQHandler, IRQF_SHARED, adc_dev[0].name, &adc_dev[0].devno);
	if(ret) {
		printk("request_irq() fialed! %d\n", ret);
		goto ERR_STEP1;
	}

	
	if(HAL_ADC_Start_DMA(&hadc, (uint32_t*)&gAdc1Value, 40) != HAL_OK)
  	{
    	printk("Start DMA error!");
  	}

	return 0;

ERR_STEP1:
	unregister_chrdev_region(adc_dev[0].devno, NUM_OF_DEVICES);
//ERR_STEP:
	cdev_del(&adc_dev[0].cdev);

	return 0;
}

static void __exit adc_exit(void)
{
	unregister_chrdev_region(MKDEV(major, minor), NUM_OF_DEVICES);
	cdev_del(&adc_dev[0].cdev);
}

module_init(adc_init);
module_exit(adc_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("jimbo_zhang");
MODULE_DESCRIPTION("adc driver");