Updating examples to Board changes, adding irq driver demo

Examples/drivers/IRQ/irq.c

@@ -0,0 +1,175 @@
+/*
+ *  Interrupt device driver demo
+ *
+ *  Author:     Andres Calderon
+ *  Created:    September 16, 2005
+ *  Copyright:  (C) 2005 emQbit Ltda
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/module.h>       /* Needed by all modules */
+#include <linux/kernel.h>       /* Needed for KERN_INFO */
+#include <linux/ioport.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>  /* We want an interrupt */
+#include <linux/irq.h>        /* We want an interrupt */
+#include <linux/platform_device.h>
+#include <linux/fs.h>
+#include <asm/delay.h>
+#include <asm/uaccess.h>  
+#include <asm/io.h>
+#include <linux/gpio.h>
+#include <asm/mach-jz4740/gpio.h>
+
+
+
+#define FPGA_IRQ_PIN          JZ_GPIO_PORTC(15)
+#define FPGA_BASE             0x15000000    //FPGA_BASE (FPGA) 0x14000000 - 0x17FFFFFF //
+#define SUCCESS               0
+#define DEVICE_NAME           "irq"    /* Dev name as it appears in /proc/devices   */
+#define BUF_LEN               80       /* Max length of the message from the device */
+
+
+  
+static int device_open(struct inode *, struct file *);
+static int device_release(struct inode *, struct file *);
+static ssize_t device_read(struct file *, char *, size_t, loff_t *);
+static ssize_t device_write(struct file *, const char *, size_t, loff_t *);
+
+static int irq_enabled = 0;
+static int is_device_open = 0; /* Is device open?  Used to prevent multiple access to device */
+static int Major; 
+
+void __iomem *ioaddress;
+static unsigned int  interrupt_counter = 0;
+
+static DECLARE_WAIT_QUEUE_HEAD(wq);
+
+
+struct file_operations fops = {
+  .owner  = THIS_MODULE,
+  .read   = device_read,
+  .write  = device_write,
+  .open   = device_open,
+  .release = device_release
+};
+
+
+
+static irqreturn_t irq_handler(int irq, void *dev_id)
+{
+  if(irq_enabled)
+  {
+    interrupt_counter++;
+    printk(KERN_INFO "interrupt_counter=%d\n",interrupt_counter);
+    wake_up_interruptible(&wq);
+  }
+  
+  return IRQ_HANDLED;
+}
+
+
+static int __init qem_init(void)
+{
+  int res, irq;
+  printk(KERN_INFO "FPGA module is Up.\n");
+  interrupt_counter = 0;
+         
+  Major = register_chrdev(0, DEVICE_NAME, &fops);         
+  
+  if (Major < 0) {
+      printk(KERN_ALERT "Registering char device failed with %d\n", Major);
+    return Major;
+  } 
+  
+  printk(KERN_ALERT  "I was assigned major number %d. To talk to\n", Major);
+  printk(KERN_ALERT  "the driver, create a dev file with\n");
+  printk(KERN_ALERT  "'mknod /dev/%s c %d 0'.\n", DEVICE_NAME, Major);
+  
+  
+  /* Set up the FGPA irq line */ 
+  irq = gpio_to_irq(FPGA_IRQ_PIN);
+  
+  res = request_irq(irq, irq_handler, IRQF_DISABLED | IRQF_TRIGGER_RISING, "FPGA - IRQ", NULL); // IRQF_TRIGGER_FALLING
+       
+  ioaddress = ioremap(FPGA_BASE, 0x4000);
+       
+  return 0;
+}
+
+
+static void __exit qem_exit(void)
+{
+//  int ret;
+  /*Tho order for free_irq, iounmap & unregister is very important */
+  free_irq(FPGA_IRQ_PIN, NULL);         
+  iounmap(ioaddress);
+  unregister_chrdev(Major, DEVICE_NAME);
+  printk(KERN_INFO "FPGA driver is down...\n");
+}
+
+
+static int device_open(struct inode *inode, struct file *file)
+{
+  if (is_device_open)
+    return -EBUSY;
+
+  is_device_open = 1;
+
+  try_module_get(THIS_MODULE);
+
+  return SUCCESS;
+}
+
+static int device_release(struct inode *inode, struct file *file)
+{ 
+  is_device_open = 0;  
+
+  module_put(THIS_MODULE);
+
+  return 0;
+}
+
+static ssize_t device_read(struct file *filp, /* see include/linux/fs.h   */
+         char *buffer,  /* buffer to fill with data */
+         size_t count, /* length of the buffer     */
+         loff_t *offset)
+{ 
+
+  wait_event_interruptible(wq, interrupt_counter!=0);
+  return copy_to_user(buffer, &interrupt_counter, sizeof(interrupt_counter)) ? -EFAULT : 0;
+}
+
+static ssize_t
+device_write(struct file *filp, const char *buff, size_t count, loff_t * off)
+{
+  const char cmd = buff[0];
+  
+  if(cmd=='Q')
+  {
+    irq_enabled = 1;
+    printk(KERN_INFO "FPGA irq_enabled...\n");
+        
+  }
+  else
+    if(cmd=='S'){
+      irq_enabled = 0;
+      printk(KERN_INFO "FPGA irq disabled.\n");
+    }
+  
+  return 1;
+}
+
+module_init(qem_init);
+module_exit(qem_exit);
+
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andres Calderon <andresn@emqbit.com>");
+MODULE_DESCRIPTION("FPGA' IRQ driver");
+MODULE_VERSION("1:0.1");