/* 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 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];

uint16_t gAdc1Value[10][7];

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)
{
	return 0;
}

static int adc_close(struct inode *inode, struct file *filep)
{
	//__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)
{
	return 0;
}

static int adc_ioctl(struct inode *inode, struct file *filep, unsigned int cmd, unsigned long arg)
{
	int i;	
	adc_arg_t adc_arg;
	if ( copy_from_user((void*)&adc_arg, (void*)arg, 1) )
	 	return -EFAULT;

	if((adc_arg.channel < 1) || (adc_arg.channel > 7))
		return -EFAULT;

	switch(cmd)
	{
		case ADC_GET_RESULT:
			for(i=0;i<10;i++)
				adc_arg.value[i] = gAdc1Value[i][adc_arg.channel-1];

			copy_to_user((void*)arg, (void*)&adc_arg, sizeof(adc_arg_t));
		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 )
// {

// 	return IRQ_HANDLED;
// }
	

int adc_hw_init(void)
{
	ADC_ChannelConfTypeDef sConfig;
	GPIO_InitTypeDef  GPIO_InitStruct;

	/* ADC1 
	 * PA0 - ADC1_IN0
	 * PA3 - ADC1_IN3
	 * PA4 - ADC1_IN4
	 * PA5 - ADC1_IN5
	 * PA6 - ADC1_IN6
	 * PB0 - ADC1_IN8
	 * PB1 - ADC1_IN9
	*/
	__HAL_RCC_GPIOA_CLK_ENABLE();
	__HAL_RCC_GPIOB_CLK_ENABLE();
	__HAL_RCC_GPIOF_CLK_ENABLE();

	GPIO_InitStruct.Pin 	= GPIO_PIN_0 | 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);

	GPIO_InitStruct.Pin 	= GPIO_PIN_0 | GPIO_PIN_1;
	GPIO_InitStruct.Mode	= GPIO_MODE_ANALOG;
	GPIO_InitStruct.Pull    = GPIO_NOPULL;
	HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
	
	GPIO_InitStruct.Pin 	= GPIO_PIN_10;
	GPIO_InitStruct.Mode	= GPIO_MODE_ANALOG;
	GPIO_InitStruct.Pull    = GPIO_NOPULL;
	HAL_GPIO_Init(GPIOF, &GPIO_InitStruct);

	__HAL_RCC_ADC1_CLK_ENABLE();
	hadc.Instance          = ADC1;
  
	hadc.Init.ClockPrescaler = ADC_CLOCKPRESCALER_PCLK_DIV8;
	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 = 7;
	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_480CYCLES;
  	sConfig.Offset = 0;
  
  	sConfig.Rank = 1;
  	sConfig.Channel = ADC_CHANNEL_0;
  	if(HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  	{
    	printk(KERN_ERR"adc channel3 init error!\n");
  	}

  	sConfig.Rank = 2;
  	sConfig.Channel = ADC_CHANNEL_3;
  	if(HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  	{
    	printk(KERN_ERR"adc channel3 init error!\n");
  	}

  	sConfig.Rank = 3;
  	sConfig.Channel = ADC_CHANNEL_4;
  	if(HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  	{
    	printk(KERN_ERR"adc channel4 init error!\n");
  	}

  	sConfig.Rank = 4;
  	sConfig.Channel = ADC_CHANNEL_5;
  	if(HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  	{
    	printk(KERN_ERR"adc channel5 init error!\n");
  	}

  	sConfig.Rank = 5;
  	sConfig.Channel = ADC_CHANNEL_6;
  	if(HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  	{
    	printk(KERN_ERR"adc channel6 init error!\n");
  	}

  	sConfig.Rank = 6;
  	sConfig.Channel = ADC_CHANNEL_8;
  	if(HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  	{
    	printk(KERN_ERR"adc channel3 init error!\n");
  	}

  	sConfig.Rank = 7;
  	sConfig.Channel = ADC_CHANNEL_9;
  	if(HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  	{
    	printk(KERN_ERR"adc channel3 init error!\n");
  	}

 // 	__HAL_ADC_ENABLE(&hadc);


  	// config dma
  	__HAL_RCC_DMA2_CLK_ENABLE();
  	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_HALFWORD;
	hdma_adc.Init.MemDataAlignment = DMA_PDATAALIGN_HALFWORD;
	hdma_adc.Init.Mode = DMA_CIRCULAR;
	hdma_adc.Init.Priority = DMA_PRIORITY_LOW;
	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);


	return 0;
}

static int __init adc_init(void)
{
	printk("adc1 module start...\n");


	//ADC1
	adc_dev[0].devno = MKDEV(MAJOR_ADC, 0);
	sprintf(adc_dev[0].name, "%s%d", DEVNAME, 1);
	register_chrdev_region(adc_dev[0].devno, 1, adc_dev[0].name);
	cdev_add(&adc_dev[0].cdev, adc_dev[0].devno, 1);
	cdev_init(&adc_dev[0].cdev, &adc_ops);

	//ADC2

	//ADC3

	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;
	// }

	// HAL_ADC_Start(&hadc);
	// HAL_DMA_Start(&hdma_adc, (uint32_t)&hadc.Instance->DR, (uint16_t*)&gAdc1Value, 40);
	
	if(HAL_ADC_Start_DMA(&hadc, (uint32_t*)gAdc1Value, 70) != HAL_OK)
  	{
    	printk("Start DMA error!");
  	}

  	// ADC_Common_TypeDef * adc_commonReg = ADC123_COMMON;
  	// printk("adc adc driver init over!, CCR = %#x\n", adc_commonReg->CCR);
  	// printk("adc CR1: %#x, CR2: %#x\n", hadc.Instance->CR1, hadc.Instance->CR2);
	return 0;

ERR_STEP1:
	unregister_chrdev_region(adc_dev[0].devno, 1);
//ERR_STEP:
	cdev_del(&adc_dev[0].cdev);

	return 0;
}

static void __exit adc_exit(void)
{
	unregister_chrdev_region(adc_dev[0].devno, 1);
	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");