nuclear@0: #include <linux/module.h>
nuclear@0: #include <linux/kernel.h>
nuclear@0: #include <linux/io.h>
nuclear@0: #include <linux/fs.h>
nuclear@1: #include <linux/interrupt.h>
nuclear@0: #include <asm/uaccess.h>
nuclear@1: #include <linux/gpio.h>
nuclear@2: #include <linux/jiffies.h>
nuclear@2: #include <linux/platform_data/bcm2708.h>
nuclear@0: 
nuclear@1: #define TEST_OUTPUT_PIN	4
nuclear@2: #define TEST_OUTPUT_GREEN	17
nuclear@1: #define TEST_INPUT_PIN	22
nuclear@0: 
nuclear@1: static int dev_init(void);
nuclear@1: static void dev_exit(void);
nuclear@1: static int dev_open(struct inode *inode, struct file *file);
nuclear@1: static int dev_close(struct inode *inode, struct file *file);
nuclear@1: static ssize_t dev_write(struct file *file, const char *buf, size_t sz, loff_t *offset);
nuclear@0: 
nuclear@1: static irqreturn_t intr_handler(int inum, void *devid, struct pt_regs *regs);
nuclear@0: 
nuclear@0: MODULE_LICENSE("GPL");
nuclear@0: MODULE_AUTHOR("John Tsiombikas");
nuclear@0: MODULE_DESCRIPTION("gpio module");
nuclear@0: 
nuclear@1: module_init(dev_init);
nuclear@1: module_exit(dev_exit);
nuclear@0: 
nuclear@0: static int major;
nuclear@1: static int intr_num = -1;
nuclear@1: static int num_presses;
nuclear@0: 
nuclear@0: static struct file_operations ops = {
nuclear@1: 	.open = dev_open,
nuclear@1: 	.release = dev_close,
nuclear@1: 	.write = dev_write
nuclear@0: };
nuclear@0: 
nuclear@1: static int dev_init(void)
nuclear@0: {
nuclear@0: 	if((major = register_chrdev(0, "gpio", &ops)) < 0) {
nuclear@0: 		printk("failed to register character device gpio (err: %d)\n", major);
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 	printk("gpio module registered (device: %d)\n", major);
nuclear@1: 
nuclear@1: 	gpio_direction_output(TEST_OUTPUT_PIN, 0);
nuclear@2: 	gpio_direction_output(TEST_OUTPUT_GREEN, 0);
nuclear@1: 
nuclear@1: 	if(gpio_request(TEST_INPUT_PIN, "test_input") != 0) {
nuclear@1: 		printk("gpio: failed to get input gpio pin\n");
nuclear@1: 		return -1;
nuclear@1: 	}
nuclear@2: 	gpio_direction_input(TEST_INPUT_PIN);
nuclear@2: 	bcm2708_gpio_setpull(gpio_to_chip(TEST_INPUT_PIN), TEST_INPUT_PIN, BCM2708_PULL_DOWN);
nuclear@1: 	if((intr_num = gpio_to_irq(TEST_INPUT_PIN)) < 0) {
nuclear@1: 		printk("gpio: failed to get interrupt line for gpio pin\n");
nuclear@1: 		return -1;
nuclear@1: 	}
nuclear@1: 	if(request_irq(intr_num, (irq_handler_t)intr_handler, IRQF_TRIGGER_RISING,
nuclear@1: 				"gpio_intr", "gpio") != 0) {
nuclear@1: 		printk("gpio: failed to setup interrupt handler\n");
nuclear@1: 		return -1;
nuclear@1: 	}
nuclear@1: 
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@1: static void dev_exit(void)
nuclear@0: {
nuclear@1: 	printk("gpio exit\n");
nuclear@2: 
nuclear@0: 	unregister_chrdev(major, "gpio");
nuclear@1: 
nuclear@1: 	if(intr_num != -1) {
nuclear@1: 		free_irq(intr_num, "gpio");
nuclear@1: 	}
nuclear@1: 	gpio_free(TEST_INPUT_PIN);
nuclear@2: 
nuclear@2: 	gpio_direction_input(TEST_OUTPUT_PIN);
nuclear@2: 	gpio_direction_input(TEST_OUTPUT_GREEN);
nuclear@2: 	bcm2708_gpio_setpull(gpio_to_chip(TEST_INPUT_PIN), TEST_INPUT_PIN, BCM2708_PULL_OFF);
nuclear@0: }
nuclear@0: 
nuclear@1: static int dev_open(struct inode *inode, struct file *file)
nuclear@0: {
nuclear@0: 	try_module_get(THIS_MODULE);
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@1: static int dev_close(struct inode *inode, struct file *file)
nuclear@0: {
nuclear@0: 	module_put(THIS_MODULE);
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@1: static ssize_t dev_write(struct file *file, const char *buf, size_t sz, loff_t *offset)
nuclear@0: {
nuclear@0: 	unsigned char val;
nuclear@0: 
nuclear@0: 	if(sz < 1) {
nuclear@0: 		return 0;
nuclear@0: 	}
nuclear@0: 	if(copy_from_user(&val, (unsigned char*)buf + sz - 1, 1) != 0) {
nuclear@0: 		return -EFAULT;
nuclear@0: 	}
nuclear@0: 
nuclear@1: 	gpio_set_value(TEST_OUTPUT_PIN, val == '0' ? 0 : 1);
nuclear@0: 	return sz;
nuclear@0: }
nuclear@0: 
nuclear@1: static irqreturn_t intr_handler(int inum, void *devid, struct pt_regs *regs)
nuclear@0: {
nuclear@2: 	static unsigned long ignore_until;
nuclear@2: 	unsigned long now = jiffies;
nuclear@2: 
nuclear@2: 	if(time_before(now, ignore_until)) {
nuclear@2: 		return IRQ_HANDLED;
nuclear@2: 	}
nuclear@2: 	ignore_until = now + 128 * HZ / 1000;
nuclear@2: 
nuclear@1: 	printk("presses: %d\n", num_presses++);
nuclear@2: 	gpio_set_value(TEST_OUTPUT_GREEN, num_presses & 1);
nuclear@1: 	return IRQ_HANDLED;
nuclear@0: }