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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/platform_device.h>
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#include <linux/ioport.h>
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#include <linux/io.h>
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#include <linux/wait.h>
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#include <linux/sched.h>
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#include <linux/semaphore.h>
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#include <linux/interrupt.h>
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#include <linux/spinlock_types.h>
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#define UINPUT_BASE 0xff200000
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#define UINPUT_SIZE PAGE_SIZE
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//#define UINPUT_INT_NUM 72
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#define UINPUT_INT_NUM 396 //insmod: ERROR: could not insert module fpga_uinput.ko: Device or resource busy
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void *fpga_uinput_mem;
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static DEFINE_SEMAPHORE(interrupt_mutex);
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static DECLARE_WAIT_QUEUE_HEAD(interrupt_wq);
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static int interrupt_flag = 0;
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static DEFINE_SPINLOCK(interrupt_flag_lock);
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static uint8_t input_state;
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//static int irq_cnt = 0;
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static irqreturn_t fpga_uinput_interrupt(int irq, void *dev_id)
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{
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if (irq != UINPUT_INT_NUM)
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{
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return IRQ_NONE;
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}
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spin_lock(&interrupt_flag_lock);
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interrupt_flag = 1;
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input_state = ioread8(fpga_uinput_mem);
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spin_unlock(&interrupt_flag_lock);
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wake_up_interruptible(&interrupt_wq);
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return IRQ_HANDLED;
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}
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static struct device_driver fpga_uinput_driver = {
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.name = "fpga_uinput",
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.bus = &platform_bus_type,
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};
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static ssize_t fpga_uinput_show(struct device_driver *drv, char *buf)
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{
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int ret;
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if (down_trylock(&interrupt_mutex))
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{
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printk(KERN_ALERT "1: KERNEL DEBUG down_trylock: Passed %s %d \n",__FUNCTION__,__LINE__);
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return -EAGAIN;
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}
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if (wait_event_interruptible(interrupt_wq, interrupt_flag != 0)) {
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ret = -ERESTART;
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printk(KERN_ALERT "2: KERNEL DEBUG release_and_exit: Passed %s %d \n",__FUNCTION__,__LINE__);
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goto release_and_exit;
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}
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spin_lock(&interrupt_flag_lock);
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interrupt_flag = 0;
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spin_unlock(&interrupt_flag_lock);
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buf[0] = input_state;
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ret = 1;
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release_and_exit:
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up(&interrupt_mutex);
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return ret;
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}
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static ssize_t fpga_uinput_store(struct device_driver *drv,
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const char *buf, size_t count)
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{
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return -EROFS;
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}
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static DRIVER_ATTR(fpga_uinput, S_IRUSR, fpga_uinput_show, fpga_uinput_store);
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static int __init fpga_uinput_init(void)
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{
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int ret;
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struct resource *res;
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printk(KERN_ALERT "3: KERNEL DEBUG fpga_uinput_init: Passed %s %d \n",__FUNCTION__,__LINE__);
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ret = driver_register(&fpga_uinput_driver);
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if (ret < 0)
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goto fail_driver_register;
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ret = driver_create_file(&fpga_uinput_driver,
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&driver_attr_fpga_uinput);
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if (ret < 0)
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goto fail_create_file;
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res = request_mem_region(UINPUT_BASE, UINPUT_SIZE, "fpga_uinput");
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if (res == NULL) {
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ret = -EBUSY;
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goto fail_request_mem;
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}
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fpga_uinput_mem = ioremap(UINPUT_BASE, UINPUT_SIZE);
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if (fpga_uinput_mem == NULL) {
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ret = -EFAULT;
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goto fail_ioremap;
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}
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ret = request_irq(UINPUT_INT_NUM, fpga_uinput_interrupt,
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0, "fpga_uinput", NULL);
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if (ret < 0)
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goto fail_request_irq;
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return 0;
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fail_request_irq:
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iounmap(fpga_uinput_mem);
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fail_ioremap:
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release_mem_region(UINPUT_BASE, UINPUT_SIZE);
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fail_request_mem:
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driver_remove_file(&fpga_uinput_driver, &driver_attr_fpga_uinput);
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fail_create_file:
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driver_unregister(&fpga_uinput_driver);
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fail_driver_register:
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return ret;
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}
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static void __exit fpga_uinput_exit(void)
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{
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free_irq(UINPUT_INT_NUM, NULL);
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iounmap(fpga_uinput_mem);
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release_mem_region(UINPUT_BASE, UINPUT_SIZE);
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driver_remove_file(&fpga_uinput_driver, &driver_attr_fpga_uinput);
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driver_unregister(&fpga_uinput_driver);
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}
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MODULE_LICENSE("Dual BSD/GPL");
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module_init(fpga_uinput_init);
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module_exit(fpga_uinput_exit);
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