proc_zlg7289.c

基于linux操作系统ATMELARM9200 开发平台的7289控制器驱动程序

/*
 * proc_zlg7289 v1.0 09/05/05
 * www.himai.com
 *
 *
 * Copyright (C) 2004 by Himai Tech
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/*
 * proc_zlg7289.c is based on procfs_example.c by Erik Mouw.
 * For more information, please see The Linux Kernel Procfs Guide, Erik Mouw
 * http://kernelnewbies.org/documents/kdoc/procfs-guide/lkprocfsguide.html
 *
*/

/* proc_zlg7289
 * This device driver demonstrates communication with a zlg7289as LED 
 * controller using SPI signalling. This routine implements SPI communication
 * in software (bit-banging). The driver creates a /proc directory entry 
 * called /proc/zlg7289/led. Scripts can write 0~9 A~F to this file for display.
 *
 * This device driver communicates with zlg7289 
 * connected in the following manner.
 *
 *    RM9200                        zlg7289as
 *     Port            Direction    
 *      PA1    43         ->        DIO    8
 *      PA2    44         ->        CLK    7
 *      
 *     cpld7128   52      ->        /CS    6
 *    
 */

/*
gcc -O2 -D__KERNEL__ -DMODULE -I/home/HM901ESP/linux-2.4.27/include -c proc_zlg7289.c -o proc_zlg7289.o
*/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>

#include <asm/io.h>
#include <asm/arch/hardware.h>	/* atmel RM9200           	*/      
#include <asm/arch/pio.h>

//#undef  DEBUG_ZLG7289
#define DEBUG_ZLG7289	1

#ifdef DEBUG_ZLG7289
#define DBG_ZLG7289(fmt, args...) printk(fmt,##args)
#else
#define DBG_ZLG7289(fmt, args...)
#endif


#define MODULE_VERSION "1.0"
#define MODULE_NAME    "proc_zlg7289"

MODULE_LICENSE("GPL");


static struct proc_dir_entry  *tb_dir,
                              *led_file;

#define ZLG7289CS      0x808c0020 

/* data port bit definitions */
#define nCS             0x0f7
#define CLK             AT91C_PIO_PA2
#define DIO             AT91C_PIO_PA1

/* bit delay time, in usecs */
#define DELAY           500

unsigned char data;
#define clkLow()       	AT91_SYS->PIOA_CODR = AT91C_PIO_PA2 
#define clkHigh()       AT91_SYS->PIOA_SODR = AT91C_PIO_PA2
#define assertCS()      writeb(0xf7, zlg7289_base)
#define deassertCS()    writeb(0xff, zlg7289_base)


#define TRAN_CMD	1
#define TRAN_CMD_DATA	2

/* User CMD */
#define ULED1_CONTROL	1
#define ULED2_CONTROL	2
#define ULED3_CONTROL	3
#define ULED4_CONTROL	4
#define ZLG_CMD		5
#define ZLG_CMD_DATA	6

static void* zlg7289_base;

static int position;

/* function zlg7289_transform
 * type: TANS_CMD        1 byte command
 *       TANS_CMD_DATA   1 byte command + 1 byte data
 *
 *
 */
static unsigned char zlg7289_transform (unsigned char cmd, unsigned char data, int type)
{
	int i;
	unsigned char bit, read_data=0;
	
	DBG_ZLG7289("zlg7289_transform cmd=%x, data=%x, type=%x\n", cmd, data, type);

	/* CS# Low */
	assertCS();
	udelay(DELAY);
	
	/* Transform CMD */
	for(i=1; i<=8; i++){
		/* CMD Output */
		bit = ( cmd >> (8-i) ) & 0x01 ;
		//DBG_ZLG7289("zlg7289_transform bit %x\n", bit);
		if( bit )
			AT91_SYS->PIOA_SODR |= AT91C_PIO_PA1;
	        else
			AT91_SYS->PIOA_CODR |= AT91C_PIO_PA1;
		udelay(DELAY);	
		/* CLK High */
		clkHigh();
		udelay(DELAY);
		/* CLK Low */
		clkLow();
		udelay(DELAY);
	}
	
	switch (type) {
		case TRAN_CMD:
			break;
		case TRAN_CMD_DATA:
			/* Transform DATA */
        		for(i=7; i>=0; i--){
			       	/* DATA Output */
				bit = ( data >> i ) & 0x01 ;
		                if( bit )
		     			AT91_SYS->PIOA_SODR |= AT91C_PIO_PA1;	
				else   
					AT91_SYS->PIOA_CODR |= AT91C_PIO_PA1;
				udelay(DELAY);
				/* CLK High */
				clkHigh();
				udelay(DELAY);
				/* CLK Low */
				clkLow();
				udelay(DELAY);
			}
		        break;	
		default:
			DBG_ZLG7289("zlg7289_transform error type %x\n", type);
			break;	
	}//end switch
	
	/* CS# High */
	deassertCS();
	udelay(DELAY);

	return read_data;
}


/*
 *  function proc_write_display
 *  This function gets called when user writes something to
 *  /proc/zlg7289/led. It contains a mapping array from numbers
 *  (0-9,a-f) to what segments to turn on
 */
static int proc_write_display(struct file *file,
				const char *buffer,
				unsigned long count, void *data)
{
//  unsigned char e, displaybuffer[9];
//  int i;

/* seg is a segment mapping table. Element 0, 0x7E, tells zlg7289 to
 * turn on the segments to display a 0. Likewise, seg's other entries 
 * map to 1 through 9
 */
//  unsigned char seg[] = { 0x7E, 0x30, 0x6D, 0x79, 0x33, 
//         		  0x5B, 0x5F, 0x70, 0x7F, 0x7B   };
  
  if (count == 0)
      return 0;
 
  DBG_ZLG7289("count = %ld  buffer = %c\n", count, buffer[0]);
 
      
  switch (buffer[0]) {
  	case  't':             /* test command */
		zlg7289_transform(0xbf, 0, TRAN_CMD);
                break;
	case  's':             /* reset command */
		zlg7289_transform(0xa4, 0, TRAN_CMD);
		break;
 	case  'l':	       /* left shiffit  */
		zlg7289_transform(0xa1, 0, TRAN_CMD);
		break;
	case  'r':             /* right shiffit */
		zlg7289_transform(0xa0, 0, TRAN_CMD);
		break;
	default:
		if ( ((buffer[0] >= '0') && (buffer[0] <= '9')) ||
                   ((buffer[0] >= 'a') && (buffer[0] <= 'f')) ) 
		{  
			if ((buffer[0] >= '0') && (buffer[0] <= '9'))   
				zlg7289_transform(0xc8 | position, buffer[0] - '0', TRAN_CMD_DATA);
			else
				zlg7289_transform(0xc8 | position, (buffer[0] -'a')+0xa, TRAN_CMD_DATA); 
		} else {
			zlg7289_transform(0x80, 0x0f, TRAN_CMD_DATA);
		
		}
		position = (position + 1) & 0x7;

		break;
  }

  return 1;		


}


/*
 * function zlg7289_hardware_init
 * This function initializes PA1 PA2 for output
 * virtual address for zlg8279-CS
 * port. The /CS and DIO lines are then put in an initialization state.
 *
 */
static void zlg7289_hardware_init (void)
{
  
	DBG_ZLG7289("zlg7289_hardware_init\n");

	AT91_SYS->PIOA_PER |= AT91C_PIO_PA1 | AT91C_PIO_PA2;
	
	AT91_SYS->PMC_PCER |= 0x00000004;

	AT91_SYS->PIOA_OER |= AT91C_PIO_PA1 | AT91C_PIO_PA2;

	zlg7289_base = ioremap_nocache(ZLG7289CS, 0x20);

	DBG_ZLG7289("zlg7289_base = 0x%08X\n", (int)zlg7289_base);

	clkHigh();
	deassertCS();

        udelay(1000);

        zlg7289_transform(0xbf,0,TRAN_CMD);     /* zlg7289 test command */

	writeb(0x00, zlg7289_base + 0x18);
}

/*
 * function init_zlg8279
 * This initialization function creates the /proc/zlg7289
 * directory and a "led" entry in it then initializes the
 * zlg7289as controller
 *
 */
static int __init init_zlg7289(void)
{
  int rv = 0;

/* Create the zlg7289 /proc entry */
  tb_dir = proc_mkdir("zlg7289", NULL);
  if(tb_dir == NULL) {
          rv = -ENOMEM;
          goto out;
  }
  tb_dir->owner = THIS_MODULE;

/* Create led and make it writable by all - 0666 */
  led_file = create_proc_entry("led", 0666, tb_dir);
  if(led_file == NULL) {
          rv = -ENOMEM;
          goto no_led_file;
  }
  led_file->data 	= NULL;
  led_file->read_proc 	= NULL;
  led_file->write_proc 	= &proc_write_display;
  led_file->owner 	= THIS_MODULE;

  zlg7289_hardware_init();

/* everything initialized */
  printk(KERN_INFO "%s %s initialized\n",
         MODULE_NAME, MODULE_VERSION);
  return 0;

no_led_file:
  remove_proc_entry("zlg7289", NULL);
out:
  return rv;
}


/*
 * function cleanup_zlg7289
 *  
 * the /proc/zlg7289 directory and the "led" entry.
 */
static void __exit cleanup_zlg7289(void)
{

  remove_proc_entry("led", tb_dir);
  remove_proc_entry("zlg7289", NULL);

  writeb(0xff, zlg7289_base + 0x20);
  iounmap (zlg7289_base);

  printk(KERN_INFO "%s %s removed\n", MODULE_NAME, MODULE_VERSION);
}


module_init(init_zlg7289);
module_exit(cleanup_zlg7289);

MODULE_AUTHOR("Feng JInFei");
MODULE_DESCRIPTION("ZLG7289AS LED");

EXPORT_NO_SYMBOLS;