#include <linux/init.h>

#include <linux/module.h>

#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/interrupt.h>

#include <linux/highmem.h>

#include <linux/spinlock.h>
#include <linux/spinlock_types.h>

#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/cdev.h>

#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/poll.h>

/*************************************************************************************************/
#define PRINT(A) printk(KERN_ALERT ">>>>> #A %x\n", A);

/*************************************************************************************************/
MODULE_AUTHOR("h4ndh"); //hediyehloo based on Talaee works
MODULE_LICENSE("Dual BSD/GPL");

/*************************************************************************************************/
static struct pci_device_id pcie_ids[] =
{
    {PCI_DEVICE(0x10ee, 0x7024)},
    {0, },
};
MODULE_DEVICE_TABLE(pci, pcie_ids);

/*************************************************************************************************/
static struct pci_dev *pcidev = NULL;

/*************************************************************************************************/
static int pcie_init(void);
static void pcie_exit(void);
static int pcie_probe (struct pci_dev *dev, const struct pci_device_id *id);
static void pcie_remove(struct pci_dev *dev);

static int chrdev_init(void);

static int usd_open_0(struct inode *inode, struct file *flip);
static int usd_close_0(struct inode *inode, struct file *filp);
static int usd_mmap_0(struct file *filp, struct vm_area_struct *vma);

static int usd_open_1(struct inode *inode, struct file *flip);
static int usd_close_1(struct inode *inode, struct file *filp);
static int usd_mmap_1(struct file *filp, struct vm_area_struct *vma);

static int usd_open_2(struct inode *inode, struct file *flip);
static int usd_close_2(struct inode *inode, struct file *filp);
static int usd_mmap_2(struct file *filp, struct vm_area_struct *vma);

/*************************************************************************************************/
static dev_t chrdev;
static struct cdev cdev;
static struct class *class = NULL;

#define DEV_NAME  "usd_reg"
#define CLASS_NAME  "usdpci"

/*************************************************************************************************/
#define TOTAL_BAR_NUM 2

struct bar_t{
  unsigned long bar_addr;
  unsigned long bar_size;
  void* bar_ptr;
  struct file_operations chrdev_fops;
};

struct bar_t bars[TOTAL_BAR_NUM];

/*************************************************************************************************/
static struct  pci_driver pci_driver =
{
  .name = CLASS_NAME,
  .id_table = pcie_ids,
	.probe = pcie_probe,
	.remove = __exit_p(pcie_remove),
};

/*************************************************************************************************/
#define PRINT_PREFIX  "USDriver PCIe"
#define PRINT_ALERT(STR)  printk(KERN_ALERT "%s %s\n", PRINT_PREFIX, STR)
#define PRINT_WARN(STR)  printk(KERN_WARN "%s %s\n", PRINT_PREFIX, STR)

/*************************************************************************************************/
static int __init pcie_init(void)
{
  int res = 0;
	PRINT_ALERT("driver initializing");

	res = pci_register_driver(&pci_driver);
	if ( res ) {
		PRINT_ALERT("device not found");
		return res;
	}

  //gone have 3 bar for now
  bars[0].chrdev_fops.owner = THIS_MODULE;
  bars[0].chrdev_fops.open = usd_open_0;
  bars[0].chrdev_fops.mmap = usd_mmap_0;
  bars[0].chrdev_fops.release = usd_close_0;
  bars[0].bar_size = 4 * 1024;

  bars[1].chrdev_fops.owner = THIS_MODULE;
  bars[1].chrdev_fops.open = usd_open_1;
  bars[1].chrdev_fops.mmap = usd_mmap_1;
  bars[1].chrdev_fops.release = usd_close_1;
  bars[1].bar_size = 128 * 1024 * 1024;

  //  bars[2].chrdev_fops = {
  //   .owner = THIS_MODULE,
  //   .open = usd_open_2,
  //   .mmap = usd_mmap_2,
  //   .release = usd_close_2
  // };
  // bars[2].bar_size = 4 * 1024;

	PRINT_ALERT("register driver success" );

	res = chrdev_init();
	if ( res ) {
		PRINT_ALERT("character device file creation failed");
		return res;
	}

	PRINT_ALERT("driver loaded");
	return res;
}

/*************************************************************************************************/
static int chrdev_init(void)
{
  PRINT_ALERT("chrdev_init");

  char name[16];
  int i = 0;
  for( ;i < TOTAL_BAR_NUM; i++)
  {
    sprintf(name, "%s_%d", DEV_NAME, i);
    proc_create(name, 0, NULL, &bars[i].chrdev_fops);
  }

  return 0;
}

/*************************************************************************************************/
static int usd_open_0(struct inode *inode, struct file *filp)
{
    return 0;
}

/*************************************************************************************************/
static int usd_open_1(struct inode *inode, struct file *filp)
{
    return 0;
}

/*************************************************************************************************/
static int usd_open_2(struct inode *inode, struct file *filp)
{
    return 0;
}

/*************************************************************************************************/
static int usd_close_0(struct inode *inode, struct file *filp)
{
	return 0;
}

/*************************************************************************************************/
static int usd_close_1(struct inode *inode, struct file *filp)
{
	return 0;
}

/*************************************************************************************************/
static int usd_close_2(struct inode *inode, struct file *filp)
{
	return 0;
}

/*************************************************************************************************/
static int usd_mmap_0(struct file *filp, struct vm_area_struct *vma)
{
  PRINT_ALERT("MMAP");

  unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
  unsigned long vsize = vma->vm_end - vma->vm_start;

  unsigned long physical = bars[0].bar_addr + off;

  unsigned int intvsize = bars[0].bar_size - off;
  // these are required for io maps, but is it okay for the buffer as well?
  vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
  vma->vm_flags |= VM_IO;
  if ( vsize < intvsize ) 
    intvsize = vsize;
  remap_pfn_range(vma, vma->vm_start, physical>>PAGE_SHIFT, intvsize, vma->vm_page_prot);

  return 0;
}

/*************************************************************************************************/
static int usd_mmap_1(struct file *filp, struct vm_area_struct *vma)
{
  PRINT_ALERT("MMAP");

  unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
  unsigned long vsize = vma->vm_end - vma->vm_start;

  unsigned long physical = bars[1].bar_addr + off;

  unsigned int intvsize = bars[1].bar_size - off;
  // these are required for io maps, but is it okay for the buffer as well?
  vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
  vma->vm_flags |= VM_IO;
  if ( vsize < intvsize ) 
    intvsize = vsize;
  remap_pfn_range(vma, vma->vm_start, physical>>PAGE_SHIFT, intvsize, vma->vm_page_prot);

  return 0;
}

/*************************************************************************************************/
static int usd_mmap_2(struct file *filp, struct vm_area_struct *vma)
{
  PRINT_ALERT("MMAP");

  unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
  unsigned long vsize = vma->vm_end - vma->vm_start;

  unsigned long physical = bars[2].bar_addr + off;

  unsigned int intvsize = bars[2].bar_size - off;
  // these are required for io maps, but is it okay for the buffer as well?
  vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
  vma->vm_flags |= VM_IO;
  if ( vsize < intvsize ) 
    intvsize = vsize;
  remap_pfn_range(vma, vma->vm_start, physical>>PAGE_SHIFT, intvsize, vma->vm_page_prot);

  return 0;
}

/*************************************************************************************************/
static int __init pcie_probe (struct pci_dev *dev, const struct pci_device_id *id)
{ 
  int rc = 0;

  rc = pci_enable_device(dev);
  if(rc)
  {
    PRINT_ALERT("driver pci_enable_device() failed");
	  goto probe_fail_enable;
  }
    
  /***************BAR 0***********************/
  if(!(pci_resource_flags(dev, 0) & IORESOURCE_MEM))
  {
      printk(KERN_ERR "USDriver PCIe driver incorrect BAR configuration\n" );
      rc = 1;
      goto probe_fail;
  }

  bars[0].bar_addr = pci_resource_start(dev, 0);
  rc = pci_request_region(dev, 0, "bar0");
  if(rc)
  {
    PRINT_ALERT("driver pci_request_regions bar0 failed");
    goto probe_fail;
  }

  bars[0].bar_ptr = pci_iomap(dev, 0, bars[0].bar_size);
  u32* bar0_data = (u32*)bars[0].bar_ptr;

  if(bar0_data == 0)
  {
    PRINT_ALERT("driver failed to map BAR 0");
    rc = 1;
    goto probe_fail_release_region;
  }

  if(!(pci_resource_flags(dev, 1) & IORESOURCE_MEM))
  {
      printk(KERN_ERR "USDriver PCIe driver incorrect BAR configuration\n" );
      rc = 1;
      goto probe_fail;
  }

  bars[1].bar_addr = pci_resource_start(dev, 1);
  rc = pci_request_region(dev, 1, "bar1");
  if(rc)
  {
    PRINT_ALERT("driver pci_request_regions bar1 failed");
    goto probe_fail;
  }

  bars[1].bar_ptr = pci_iomap(dev, 1, bars[1].bar_size);
  u32* bar1_data = (u32*)bars[1].bar_ptr;

  if(bar1_data == 0)
  {
    PRINT_ALERT("driver failed to map BAR 1");
    rc = 1;
    goto probe_fail_release_region;
  }

  pci_set_master(dev);

  printk(KERN_ALERT "-----------------------------------\n");
  printk(KERN_ALERT "BAR0 reg 0 = 0x%x\n", *bar0_data);
  *bar1_data = 0x12345678;
  printk(KERN_ALERT "BAR1 reg 0 = 0x%x\n", ioread32(bar1_data));
  printk(KERN_ALERT "-----------------------------------\n");

  return 0;

  probe_fail_release_region:
    pci_release_regions(dev);
  probe_fail:
    pci_disable_device(dev);
  probe_fail_enable:
    return rc;
}

/*************************************************************************************************/
static void pcie_remove(struct pci_dev *dev)
{
  PRINT_ALERT("remove driver");

	pci_clear_master(dev);
	PRINT_ALERT("Cleared PCIe master");

	pci_iounmap(dev, bars[0].bar_ptr);
  pci_iounmap(dev, bars[1].bar_ptr);
	PRINT_ALERT("IOunmap");

	pci_release_regions(dev);
	PRINT_ALERT("pci_release_regions");

	pci_disable_device(dev);
	PRINT_ALERT("pci_disable_device");
}

/*************************************************************************************************/
static void __exit pcie_exit(void)
{
	PRINT_ALERT("driver unloading");

	PRINT_ALERT("driver unregistering");
	pci_unregister_driver(&pci_driver);
  
  char name[16];
  int i = 0;
  for( ; i < TOTAL_BAR_NUM; i++)
  {
    snprintf(name, 8, "%s%d", DEV_NAME, i);
    remove_proc_entry(name, NULL);
  }

	PRINT_ALERT("driver unloaded");
}

module_init(pcie_init);
module_exit(pcie_exit);

/*************************************************************************************************/
/*************************************************************************************************/
/*************************************************************************************************/
/*************************************************************************************************/
/*************************************************************************************************/
/*************************************************************************************************/
/*************************************************************************************************/
/*************************************************************************************************/