Mity CPU Platforms » MitySOM-5CSX Altera Cyclone V

#include <linux/init.h>

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/device.h>

#include <linux/platform_device.h>

#include <linux/ioport.h>

#include <linux/io.h>

#include <linux/wait.h>

#include <linux/sched.h>

#include <linux/semaphore.h>

#include <linux/interrupt.h>

#include <linux/spinlock_types.h>

#define UINPUT_BASE 0xff200000

#define UINPUT_SIZE PAGE_SIZE

//#define UINPUT_INT_NUM 72

#define UINPUT_INT_NUM 396   //insmod: ERROR: could not insert module fpga_uinput.ko: Device or resource busy

void *fpga_uinput_mem;

static DEFINE_SEMAPHORE(interrupt_mutex);

static DECLARE_WAIT_QUEUE_HEAD(interrupt_wq);

static int interrupt_flag = 0;

static DEFINE_SPINLOCK(interrupt_flag_lock);

static uint8_t input_state;

//static int irq_cnt = 0;

static irqreturn_t fpga_uinput_interrupt(int irq, void *dev_id)

{

   if (irq != UINPUT_INT_NUM)

   {

      return IRQ_NONE;

   }

   spin_lock(&interrupt_flag_lock);

   interrupt_flag = 1;

   input_state = ioread8(fpga_uinput_mem);

   spin_unlock(&interrupt_flag_lock);

   wake_up_interruptible(&interrupt_wq);

   return IRQ_HANDLED;

}

static struct device_driver fpga_uinput_driver = {

   .name = "fpga_uinput",

   .bus = &platform_bus_type,

};

static ssize_t fpga_uinput_show(struct device_driver *drv, char *buf)

{

   int ret;

   if (down_trylock(&interrupt_mutex))

   {

      printk(KERN_ALERT "1: KERNEL DEBUG down_trylock: Passed %s %d \n",__FUNCTION__,__LINE__);             

      return -EAGAIN;

   }

   if (wait_event_interruptible(interrupt_wq, interrupt_flag != 0)) {

      ret = -ERESTART;

      printk(KERN_ALERT "2: KERNEL DEBUG release_and_exit: Passed %s %d \n",__FUNCTION__,__LINE__);         

      goto release_and_exit;

   }

   spin_lock(&interrupt_flag_lock);

   interrupt_flag = 0;

   spin_unlock(&interrupt_flag_lock);

   buf[0] = input_state;

   ret = 1;

release_and_exit:

   up(&interrupt_mutex);

   return ret;

}

static ssize_t fpga_uinput_store(struct device_driver *drv,

      const char *buf, size_t count)

{

   return -EROFS;

}

static DRIVER_ATTR(fpga_uinput, S_IRUSR, fpga_uinput_show, fpga_uinput_store);

static int __init fpga_uinput_init(void)

{

   int ret;

   struct resource *res;

    printk(KERN_ALERT "3: KERNEL DEBUG fpga_uinput_init: Passed %s %d \n",__FUNCTION__,__LINE__);  

   ret = driver_register(&fpga_uinput_driver);

   if (ret < 0)

      goto fail_driver_register;

   ret = driver_create_file(&fpga_uinput_driver,

         &driver_attr_fpga_uinput);

   if (ret < 0)

      goto fail_create_file;

   res = request_mem_region(UINPUT_BASE, UINPUT_SIZE, "fpga_uinput");

   if (res == NULL) {

      ret = -EBUSY;

      goto fail_request_mem;

   }

   fpga_uinput_mem = ioremap(UINPUT_BASE, UINPUT_SIZE);

   if (fpga_uinput_mem == NULL) {

      ret = -EFAULT;

      goto fail_ioremap;

   }

   ret = request_irq(UINPUT_INT_NUM, fpga_uinput_interrupt,

         0, "fpga_uinput", NULL);

   if (ret < 0)

      goto fail_request_irq;

   return 0;

fail_request_irq:

   iounmap(fpga_uinput_mem);

fail_ioremap:

   release_mem_region(UINPUT_BASE, UINPUT_SIZE);

fail_request_mem:

   driver_remove_file(&fpga_uinput_driver, &driver_attr_fpga_uinput);

fail_create_file:

   driver_unregister(&fpga_uinput_driver);

fail_driver_register:

   return ret;

}

static void __exit fpga_uinput_exit(void)

{

   free_irq(UINPUT_INT_NUM, NULL);

   iounmap(fpga_uinput_mem);

   release_mem_region(UINPUT_BASE, UINPUT_SIZE);

   driver_remove_file(&fpga_uinput_driver, &driver_attr_fpga_uinput);

   driver_unregister(&fpga_uinput_driver);

}

MODULE_LICENSE("Dual BSD/GPL");

module_init(fpga_uinput_init);

module_exit(fpga_uinput_exit);