at91_mygpio.c

gpio driver for atmel ar91rm92

/*======================================================================
	current file::/drivers/at91/mygpio/at91_mygpio.c
	Device driver for the GPIO(PIO) control of Atmel AT91RM9200
	(c)e-tek Ltd,Shenzhen,Guangdong,China

	The original code is created by beeswing<[e-mail]>. 
	20060216 add portb irq handle as a share read
	
	Copyright (C) 2005 beeswing.  
	All Rights Reserved.    
======================================================================*/ 
   
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/proc_fs.h>
#include <linux/init.h>

#ifdef CONFIG_DEVFS_FS
#include <linux/devfs_fs_kernel.h>
#endif

#include <asm/io.h>
#include <asm/arch/hardware.h>

#include	"at91_mygpio.h"

///#define GPIO_DEBUG	1

#define PORT(x)		((x >> 8) & 0x0F)
#define GPIO(x)		(x & 0xFF)
#define PORT_MAX	NR_GPIO_DEVICES
#define GPIO_MAX	32

extern AT91PS_SYS AT91_SYS;

#ifdef	CONFIG_PORTS_SHARE_IRQ		
	unsigned long ports_irq_status[4];
	static unsigned int port_dev_id[4];	
#endif

#ifdef CONFIG_DEVFS_FS
static devfs_handle_t devfs_handle = NULL;
#endif


//check if gpio or AB select function 1=gpio
static int check_gpio_fun(AT91PS_PIO PORT, unsigned int num)
{
        return (PORT->PIO_PSR & PIO_GPIO(num)) ? 1 : 0;
}

//check the direction: 1 = output
static int check_gpio_direct(AT91PS_PIO PORT, unsigned int num)
{
        return (PORT->PIO_OSR & PIO_GPIO(num)) ? 1 : 0;
}


static ssize_t gpio_write(struct file * file, const char * buf, size_t count, loff_t * ppos)
{
	unsigned int gpio_arg = file->private_data;
	unsigned int gpio_device = PORT(gpio_arg);
	unsigned int pin_num = GPIO(gpio_arg);
	AT91PS_PIO AT91_PORT = (AT91PS_PIO)(unsigned long)(AT91C_VA_BASE_SYS + 0x400 + 0x200 * gpio_device);

	if (gpio_device >= NR_GPIO_DEVICES)
		return -ENODEV;

	if (!check_gpio_fun(AT91_PORT, pin_num)) {
		printk(KERN_ERR "IO not a gpio!\n");
	  	return -EIO;
	}

	if (!check_gpio_direct(AT91_PORT, pin_num)) {
		printk(KERN_ERR "Not a output gpio!\n");
	  	return -EIO;
	}

#ifdef	GPIO_DEBUG
	printk("MYgpio write port %d pin %d:data %c!\n", gpio_device,pin_num,*buf);
#endif

	if ( (*buf) == '1')
		AT91_PORT->PIO_SODR = PIO_GPIO(pin_num);
	else if ( (*buf) == '0')
		AT91_PORT->PIO_CODR = PIO_GPIO(pin_num);
	return 1;
}

//
static ssize_t gpio_read (struct file * file, char * buf, size_t count, loff_t * ppos) 
{
	unsigned int gpio_arg = file->private_data;
	unsigned int gpio_device = PORT(gpio_arg);
	unsigned int pin_num = GPIO(gpio_arg);
	AT91PS_PIO AT91_PORT = (AT91PS_PIO)(unsigned long)(AT91C_VA_BASE_SYS + 0x400 + 0x200 * gpio_device);

	if (gpio_device >= NR_GPIO_DEVICES)
		return -ENODEV;
	
	if (!check_gpio_fun(AT91_PORT, pin_num)) {
		printk(KERN_ERR "IO not a gpio!\n");
	  	return -EIO;
	}

	if (check_gpio_direct(AT91_PORT, pin_num)) {
		printk(KERN_ERR "Not a input gpio!\n");
	 	return -EIO;
	}

	*buf = (AT91_PORT->PIO_PDSR & PIO_GPIO(pin_num))? '1':'0';
	
#ifdef	GPIO_DEBUG	
	printk("MYgpio read port %d pin %d data:%c!\n",gpio_device, pin_num, *buf);
#endif

	return 1;
}

//arg include input pin_num

static int gpio_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	unsigned int gpio_device = MINOR(inode->i_rdev);
	unsigned int pin_num = GPIO(arg);
	AT91PS_PIO AT91_PORT = (AT91PS_PIO)(unsigned long)(AT91C_VA_BASE_SYS + 0x400 + 0x200 * gpio_device);
	
	if (gpio_device >= NR_GPIO_DEVICES)
		return -ENODEV;

#ifdef	MYGPIO_DEBUG
	printk(KERN_INFO "mygpio minor: %X \n",gpio_device);
#endif

	if (pin_num > GPIO_MAX)
	{
		printk(KERN_ERR "mygpio IO error in ioctl!\n");
		return -EIO;
	}
	
#ifdef	MYGPIO_DEBUG
	printk(KERN_INFO "mygpio pin NO: %d\n",pin_num);
#endif

	//map physical address this method is OK
	//move to open function
	///AT91_PORT = (AT91PS_PIO)(unsigned long)(AT91C_VA_BASE_SYS + 0x400 + 0x200 * gpio_device);

#ifdef	MYGPIO_DEBUG
	printk("mygpio ioctl setting cmd:%X Arg: %X port_base: %X \n",cmd,arg,AT91_PORT);
#endif
	switch (cmd) 
	{
	
 	  case PIO_SET_PASR:
		AT91_PORT->PIO_ASR = PIO_GPIO(pin_num); 
		AT91_PORT->PIO_PDR = PIO_GPIO(pin_num);
		break; 
	
	  case PIO_SET_PBSR:
		AT91_PORT->PIO_BSR = PIO_GPIO(pin_num); 
		AT91_PORT->PIO_PDR = PIO_GPIO(pin_num); 
		break;

	  case PIO_SET_GPIO:
		AT91_PORT->PIO_PER = PIO_GPIO(pin_num); 
		break;

	  case PIO_SET_INPUT:
		AT91_PORT->PIO_ODR = PIO_GPIO(pin_num); 
		break;

	  case PIO_SET_OUTPUT:
		AT91_PORT->PIO_OER = PIO_GPIO(pin_num); 
		break;

	  default:
                return -EINVAL;
	}

	(unsigned int) file->private_data = (gpio_device << 8) | pin_num;

	return 0;
}


static int gpio_open(struct inode *inode, struct file *file)
{
	unsigned int gpio_device = MINOR(inode->i_rdev);
	//move from ioctl
	AT91PS_PIO AT91_PORT = (AT91PS_PIO)(unsigned long)(AT91C_VA_BASE_SYS + 0x400 + 0x200 * gpio_device);

	if (gpio_device >= NR_GPIO_DEVICES)
		return -ENODEV;
	
	MOD_INC_USE_COUNT;
	
	AT91_SYS->PMC_PCER = 1 << (AT91C_ID_PIOA + gpio_device);	

#ifdef	GPIO_DEBUG	
	printk(KERN_INFO "mygpio open port %d add:%X \n", gpio_device,AT91_PORT);
#endif
	return 0;

}

static int gpio_close(struct inode *inode, struct file *file)
{
	unsigned int gpio_device = MINOR(inode->i_rdev);

	if (gpio_device >= NR_GPIO_DEVICES)
		return -ENODEV;

	//disable peripheral clock 
	AT91_SYS->PMC_PCDR = 1 << (AT91C_ID_PIOA + gpio_device);
	MOD_DEC_USE_COUNT;

#ifdef	GPIO_DEBUG	
	printk(KERN_INFO "mygpio close port %d add:%X \n", gpio_device,AT91_PORT);
#endif
	return 0;
}

#ifdef	CONFIG_PORTS_SHARE_IRQ
static void port_interrupt_handle(int irq, void *dev_id, struct pt_regs *regs)
{
	AT91PS_PIO at91_gport = (AT91PS_PIO)(unsigned long)(AT91C_VA_BASE_SYS + 0x400 + 0x200 * (irq - AT91C_ID_PIOA));
	ports_irq_status[irq - AT91C_ID_PIOA] = at91_gport->PIO_ISR & at91_gport->PIO_IMR;
	//printk("mygpio.c port(%d) irq status = %X\n", irq - AT91C_ID_PIOA, ports_irq_status[irq - AT91C_ID_PIOA]);
}
#endif

//file operations
static struct file_operations gpio_fops = {
	owner:	THIS_MODULE,
	read:	gpio_read,
	write:	gpio_write,
	ioctl:	gpio_ioctl,
	open:	gpio_open,
	release:	gpio_close,
};


/*
 * Main initialization routine
 */
static int __init init_gpio(void)
{
	unsigned int i;
#ifdef CONFIG_DEVFS_FS
	unsigned char *devname;
	if (devfs_register_chrdev(GPIO_MAJOR, "mygpio", &gpio_fops)) {
#else
	if (register_chrdev(GPIO_MAJOR, "mygpio", &gpio_fops)) {
#endif
		printk(KERN_ERR "mygpio: unable to get major %d\n", GPIO_MAJOR);
		return -EIO;
	}
		
#ifdef CONFIG_DEVFS_FS
	devfs_handle = devfs_mk_dir(NULL, "mygpio", NULL);
	if (!devfs_handle) return -EBUSY;
		
	devfs_register_series (devfs_handle, "port%u", NR_GPIO_DEVICES,		\
		DEVFS_FL_DEFAULT, 						\
		GPIO_MAJOR, 0, S_IFCHR | S_IRUGO | S_IWUGO,			\
		&gpio_fops, NULL);

#endif

#ifdef	CONFIG_PORTS_SHARE_IRQ
	for (i = 0; i < PORTS_NUM; i++){	
		if (request_irq(AT91C_ID_PIOA + i, port_interrupt_handle, SA_SHIRQ, "mygpio", &port_dev_id[i])){
			printk(KERN_ERR "can not get assigned ports irq %d\n", AT91C_ID_PIOA+i);
		}
	}
#endif
	printk(KERN_INFO "mygpio driver initialized by beeswing!\n");
	return 0;
}


static void __exit gpio_cleanup(void)
{

#ifdef	CONFIG_PORTS_SHARE_IRQ
	int i;
	for (i = 0; i < PORTS_NUM; i++){
		free_irq(AT91C_ID_PIOA + i, &port_dev_id[i]);
	}
#endif

#ifdef CONFIG_DEVFS_FS
	devfs_unregister(devfs_handle);
	if (devfs_unregister_chrdev(GPIO_MAJOR, "mygpio"))
#else
	if (unregister_chrdev(GPIO_MAJOR, "mygpio"))
#endif
	printk(KERN_ERR "at91_mygpio: Unable to release major %d for gpio\n", GPIO_MAJOR);
	return;

}

EXPORT_NO_SYMBOLS;

MODULE_AUTHOR("Beeswing");
MODULE_DESCRIPTION("GPIO driver for Atmel AT91RM9200");
MODULE_LICENSE("GPL");

module_init(init_gpio);
module_exit(gpio_cleanup);