parport_2410_16c552.c

我为S3C2410写的扩展并口驱动程序

/* S3C2410 开发板扩展并口16C552的low-level驱动
 *
 * Author: Allen He<[e-mail]>
 *
 *
 *
 * The extended parallel port provides one port at a fixed address
 * with 8 output data lines (D0 - D7), 1 output control line (STROBE)
 * and 1 input status line (BUSY) able to cause an interrupt.
 */

//#define MODULE  //HYL Add 
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/parport.h>
#include <linux/slab.h>
#include <linux/ioport.h>


#include <asm/irq.h>
#include <asm/hardware.h>
#include <asm/arch/cpu_s3c2410.h>
#include <asm/arch/parport_2410_16c552.h>

static struct parport *this_port = NULL;

 unsigned char
parport_16c552_read_data(struct parport *p)
{
	unsigned long flags;
	unsigned char data;

	save_flags(flags);
	cli();
	data=*((unsigned char *)(p->base+0x0)) ;
	restore_flags(flags);
	return data;
}

static void
parport_16c552_write_data(struct parport *p, unsigned char data)
{
	unsigned long flags;

	save_flags(flags);
	cli();
	*((unsigned char *)(p->base+0x0))=data;
	restore_flags(flags);
	return;
}



unsigned char parport_16c552_read_control(struct parport *p)
{
	unsigned long flags;
	unsigned char control = 0;

	save_flags(flags);
	cli();
	control=*((unsigned char *)(p->base+0x2));
	restore_flags(flags);
	return control;

}

void parport_16c552_write_control(struct parport *p, unsigned char d)
{

	unsigned long flags;

	save_flags(flags);
	cli();
	*((unsigned char *)(p->base+0x2))=d;
	restore_flags(flags);
	return;
}

static unsigned char
parport_16c552_frob_control(struct parport *p, unsigned char mask,
			   unsigned char val)
{
	unsigned char old = parport_16c552_read_control(p);
	parport_16c552_write_control(p, (old & ~mask) ^ val);
	return old;
}

static unsigned char
parport_16c552_read_status(struct parport *p)
{
	return (*((unsigned char *)(p->base+0x1)));
}

static void
parport_16c552_init_state(struct pardevice *d, struct parport_state *s)
{
}

static void
parport_16c552_save_state(struct parport *p, struct parport_state *s)
{
}

static void
parport_16c552_restore_state(struct parport *p, struct parport_state *s)
{
}

static void
parport_16c552_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	parport_generic_irq(irq, (struct parport *) dev_id, regs);
}

static void
parport_16c552_enable_irq(struct parport *p)
{
	enable_irq(INT_EINT8_23);
}

static void
parport_16c552_disable_irq(struct parport *p)
{
	disable_irq(INT_EINT8_23);
}

static void
parport_16c552_data_forward(struct parport *p)
{
	unsigned long flags;
	save_flags(flags);
	cli();
	parport_16c552_frob_control(p,0x20,0x0);
	restore_flags(flags);
}

static void
parport_16c552_data_reverse(struct parport *p)
{
	unsigned long flags;
	save_flags(flags);
	cli();
	parport_16c552_frob_control(p,0x20,0x20);
	restore_flags(flags);
}

static void
parport_16c552_inc_use_count(void)
{
	MOD_INC_USE_COUNT;
}

static void
parport_16c552_dec_use_count(void)
{
	MOD_DEC_USE_COUNT;
}

static struct parport_operations parport_16c552_ops = {
	parport_16c552_write_data,
	parport_16c552_read_data,

	parport_16c552_write_control,
	parport_16c552_read_control,
	parport_16c552_frob_control,

	parport_16c552_read_status,

	parport_16c552_enable_irq,
	parport_16c552_disable_irq,

	parport_16c552_data_forward,
	parport_16c552_data_reverse,

	parport_16c552_init_state,
	parport_16c552_save_state,
	parport_16c552_restore_state,

	parport_16c552_inc_use_count,
	parport_16c552_dec_use_count,

	parport_ieee1284_epp_write_data,
	parport_ieee1284_epp_read_data,
	parport_ieee1284_epp_write_addr,
	parport_ieee1284_epp_read_addr,

	parport_ieee1284_ecp_write_data,
	parport_ieee1284_ecp_read_data,
	parport_ieee1284_ecp_write_addr,

	parport_ieee1284_write_compat,
	parport_ieee1284_read_nibble,
	parport_ieee1284_read_byte,
};


int __init
parport_16c552_init(void)
{
	struct parport *p;
	unsigned long flags;

		/*分配内存区域*/
		if(check_mem_region(brd_16c552_parportbase,0x800))//0x800 is a number defined as will.
		{
			printk("16c552 driver:memory already in use\n");
			return -EBUSY;
		}
		request_mem_region(brd_16c552_parportbase,0x800,"parport_16c552");		
		
		p = parport_register_port(brd_16c552_parportbase,INT_EINT8_23,
					  PARPORT_DMA_NONE,
					  &parport_16c552_ops);
		if (!p)
			return 0;
		if (request_irq(INT_EINT8_23, parport_16c552_interrupt,
				SA_SHIRQ, p->name, p)) {
			parport_unregister_port (p);
			return 0;
		}
	
/*		// initialize the parport as a input device with disabling irq. 
		save_flags(flags);
		cli();
		parport_16c552_frob_control(p,0x3f,0x24);		
		restore_flags(flags);
*/


		this_port = p;
		printk(KERN_INFO "%s: s3c2410 brd extended with 16c552, port using irq\n", p->name);
		
		parport_proc_register(p);

		parport_announce_port (p);

		return 1;
	
}

#ifdef MODULE

MODULE_AUTHOR("Wingwind");
MODULE_DESCRIPTION("Parport Driver for 16c552 parellel Port");
MODULE_SUPPORTED_DEVICE("S3c2410 extending 16c552 Parallel Port");
MODULE_LICENSE("GPL");

int
init_module(void)
{
	return parport_16c552_init() ? 0 : -ENODEV;
}

void
cleanup_module(void)
{
	if (this_port->irq != PARPORT_IRQ_NONE)
		free_irq(IRQ_MFP_BUSY, this_port);
	parport_proc_unregister(this_port);
	parport_unregister_port(this_port);
	release_mem_region(brd_16c552_parportbase,0x800,);	
}
#endif