gpio_key.c

atmel gpio driver for linux-2.6.20

/*
 * Driver for keys on GPIO lines capable of generating interrupts.
 *
 * Copyright 2005 Phil Blundell
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/version.h>

#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/irq.h>
#include <linux/gpio_keys.h>
#include <asm/gpio.h>

#define AT_GPIO_MODULE	"AT_GPIO"
#define TRACE \    
 printk("%s: %s(): line %d\n", AT_GPIO_MODULE, __FUNCTION__, __LINE__)

/**
 * input_set_capability - mark device as capable of a certain event
 * @dev: device that is capable of emitting or accepting event
 * @type: type of the event (EV_KEY, EV_REL, etc...)
 * @code: event code
 *
 * In addition to setting up corresponding bit in appropriate capability
 * bitmap the function also adjusts dev->evbit.
 */

/* 记录本设备对于哪些事件感兴趣(对其进行处理)*/
void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
{
	TRACE;
	switch (type) {
    case EV_KEY:
        __set_bit(code, dev->keybit);//比如按键,应该对哪些键值的按键进行处理(对于其它按键不予理睬)
        break;

    case EV_REL:
        __set_bit(code, dev->relbit);
        break;

    case EV_ABS:
        __set_bit(code, dev->absbit);
        break;

    case EV_MSC:
        __set_bit(code, dev->mscbit);
        break;

    case EV_SW:
        __set_bit(code, dev->swbit);
        break;

    case EV_LED:
        __set_bit(code, dev->ledbit);
        break;

    case EV_SND:
        __set_bit(code, dev->sndbit);
        break;

    case EV_FF:
        __set_bit(code, dev->ffbit);
        break;

    default:
        printk(KERN_ERR
            "input_set_capability: unknown type %u (code %u)\n",
            type, code);
        dump_stack();
        return;
    }

    __set_bit(type, dev->evbit);//感觉和前面重复了(前面一经配置过一次了)
}
EXPORT_SYMBOL(input_set_capability);


static struct gpio_plat_data{

unsigned int  flags;
};

static struct file_operations gpio_key={

        .owner  = THIS_MODULE,
};

static  struct  cdev *gpio_keys;

#define gpio_PLATF_16BITONLY 0x0008

static struct gpio_plat_data gpio_platdata = {
        .flags          = gpio_PLATF_16BITONLY,
};

static struct platform_device gpio_device = {
        .name           = "gpio",
        .id             = 0,
        .num_resources  = 0,
        .resource       = NULL,
        .dev            = {
                .platform_data  = &gpio_platdata,
        }
};

struct platform_device *pdev;

static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
{
	int i;
	struct platform_device *pdev = dev_id;
	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
	struct input_dev *input = platform_get_drvdata(pdev);
	TRACE;
	for (i = 0; i < pdata->nbuttons; i++) {
		struct gpio_keys_button *button = &pdata->buttons[i];
		int gpio = button->gpio;

		if (irq == gpio_to_irq(gpio)) {
			unsigned int type = button->type ?: EV_KEY;
			int state = (gpio_get_value(gpio) ? 1 : 0) ^ button->active_low;

			input_event(input, type, button->code, !!state);
			input_sync(input);
		}
	}
	TRACE;
	printk("return IRQ_HANDLED is :%x \n",IRQ_HANDLED);
	return IRQ_HANDLED;

}



static int __exit gpio_keys_remove(void)
{

	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
	struct input_dev *input = platform_get_drvdata(pdev);
	int i;
	TRACE;
	for (i = 0; i < pdata->nbuttons; i++) {
		int irq = gpio_to_irq(pdata->buttons[i].gpio);
		free_irq(irq, pdev);
	}

	input_unregister_device(input);

	return 0;
}


struct platform_driver gpio_keys_device_driver = {
//		.probe		= gpio_keys_probe,
		.remove		= __devexit_p(gpio_keys_remove),
		.driver		= {
		.name	= "gpio-keys",
		.owner  = THIS_MODULE,
	}
};



struct platform_device dev;
struct gpio_keys_platform_data data;


static int __init gpio_keys_init(void)
{
		
    struct platform_device *pdev=&dev;

   struct gpio_keys_platform_data *pdata = pdev->dev.platform_data =&data;
    
	TRACE;
	struct input_dev *input;
	int i, error;
	TRACE;
	platform_device_register(&gpio_device);
	input = input_allocate_device();
	if (!input)
		return -ENOMEM;
	TRACE;
	platform_set_drvdata(pdev, input);
//	platform_set_drvdata(pdata, input);
	TRACE;
//	cdev_init(gpio_keys,&gpio_key);
	input->evbit[0] = BIT(EV_KEY);
	TRACE;

	input->name = pdev->name;
	input->phys = "gpio-keys/input0";
//	input->dev.parent = &pdev->dev;
	input->cdev.parent = &pdev->dev;
	TRACE;

	input->id.bustype = BUS_HOST;
	input->id.vendor = 0x0001;
	input->id.product = 0x0001;
	input->id.version = 0x0100;
	TRACE;
	pdata->nbuttons =4;
	TRACE;
/*	
	pdata->buttons[0].gpio =AT91_PIN_PA24; 
	pdata->buttons[1].gpio =AT91_PIN_PA25; 
	pdata->buttons[2].gpio =AT91_PIN_PA28; 
	pdata->buttons[3].gpio =AT91_PIN_PA29; 
	TRACE;
	pdata->buttons[0].code = KEY_A;
	pdata->buttons[1].code = KEY_B;
	pdata->buttons[2].code = KEY_C;
	pdata->buttons[3].code = KEY_D;
	TRACE;
	pdata->buttons[0].type = EV_KEY;
	pdata->buttons[1].type = EV_KEY;
	pdata->buttons[2].type = EV_KEY;
	pdata->buttons[3].type = EV_KEY;
	TRACE;
*/	
	for (i = 0; i < pdata->nbuttons; i++) {

		struct gpio_keys_button *button = &pdata->buttons[i];
		
		switch (i){
				case 0:
		        button->gpio =AT91_PIN_PA24;
		        button->code =KEY_A;
				TRACE;
				break;
				case 1:
				  button->gpio =AT91_PIN_PA25;
		        button->code =KEY_B;
				TRACE;
			    break;

				case 2:
					  button->gpio =AT91_PIN_PA28;
		        button->code =KEY_C;
				TRACE;
				break;
				case 3:
				  button->gpio =AT91_PIN_PA29;
		        button->code =KEY_D;	
				TRACE;
				break;

		}
			

		int irq = gpio_to_irq(button->gpio);
		unsigned int type = button->type ?: EV_KEY;

		set_irq_type(irq, IRQ_TYPE_EDGE_BOTH);
		error = request_irq(irq, gpio_keys_isr, IRQF_SAMPLE_RANDOM,
				     button->desc ? button->desc : "gpio_keys",
				     pdev);
		if (error) {
			printk(KERN_ERR "gpio-keys: unable to claim irq %d; error %d\n",
				irq, error);
			goto fail;
		}
		TRACE;
		input_set_capability(input, type, button->code);
	  
}
	error = input_register_device(input);
	if (error) {
		printk(KERN_ERR "Unable to register gpio-keys input device\n");
		goto fail;
	}

	return 0;

 fail:
	for (i = i - 1; i >= 0; i--)
		free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev);

	input_free_device(input);

	return error;

}

#if 0
static void __exit gpio_keys_exit(void)
{
	platform_driver_unregister(&gpio_keys_device_driver);
}

#endif

module_init(gpio_keys_init);
module_exit(gpio_keys_remove);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Phil Blundell <[e-mail]>");
MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");