基于s3c2440的12864液晶驱动

末蓝、 2022-03-26 14:10 214阅读 0赞

12864是128\*64[点阵][Link 1]液晶模块的点阵数简称，业界约定俗成的简称。

一、液晶显示模块概述  
12864A-1 汉字图形点阵液晶显示模块,可显示汉字及图形,内置 8192 个中文汉字(16X16 点阵,16\*8=128,16\*4=64,一行只能写 8 个汉字,4 行;、128 个字符(8X16 点阵)及 64X256 点阵显示 RAM(GDRAM))。  
主要技术参数和显示特性:  
电源:VDD 3.3V~+5V(内置升压电路,无需负压);  
显示内容:128 列× 64 行(128 表示点数)  
显示颜色:黄绿  
显示角度:6:00 钟直视  
LCD 类型:STN  
与 MCU 接口:8 位或 4 位并行/3 位串行  
配置 LED 背光  
多种软件功能:光标显示、画面移位、自定义字符、睡眠模式等

引脚定义：D0-D7，RS，RES，RD，WR，CS，BL；具体头文件定义如下：

\#ifndef LCD12864\_H  
 \#define  LCD12864\_H   
  
 \#define  LCD12864\_MAJOR 242   
 \#define  DEV\_NAME "lcd12864"   
  
 \#define  LCD12864\_IOCTL 'l'   
 \#define  SET\_FONT\_SIZE \_IOW(LCD12864\_IOCTL,0 ,unsigned int)   
 \#define  SET\_LCD\_PAGE \_IOW(LCD12864\_IOCTL,1 ,unsigned int)   
 \#define  SET\_LCD\_COLUMN \_IOW(LCD12864\_IOCTL,2 ,unsigned int)   
 \#define  CLR\_SCREEN \_IOW(LCD12864\_IOCTL,3 ,unsigned int)   
 \#define  BACKLIGHT\_CTRL \_IOW(LCD12864\_IOCTL,4 ,unsigned int)   
 \#define  CONTRAST\_SETTING \_IOW(LCD12864\_IOCTL,5 ,unsigned int)   
  
 \#define  LCD\_DATA\_0 S3C2410\_GPC8   
 \#define  LCD\_DATA\_1 S3C2410\_GPC9   
 \#define  LCD\_DATA\_2 S3C2410\_GPC10   
 \#define  LCD\_DATA\_3 S3C2410\_GPC11   
  
 \#define  LCD\_DATA\_4 S3C2410\_GPC12   
 \#define  LCD\_DATA\_5 S3C2410\_GPC13   
 \#define  LCD\_DATA\_6 S3C2410\_GPC14   
 \#define  LCD\_DATA\_7 S3C2410\_GPC15   
  
  
 \#define  LCD\_E\_RD S3C2410\_GPD0   
 \#define  LCD\_RW\_WR S3C2410\_GPD1   
 \#define  LCD\_RS S3C2410\_GPD2   
 \#define  LCD\_RES S3C2410\_GPD3   
 \#define  LCD\_CS1 S3C2410\_GPD4   
 \#define  LCD\_BL S3C2410\_GPD5   
  
  
 \#define  LCD\_DATA\_CFG0\_OUTP S3C2410\_GPC8\_OUTP   
 \#define  LCD\_DATA\_CFG1\_OUTP S3C2410\_GPC9\_OUTP   
 \#define  LCD\_DATA\_CFG2\_OUTP S3C2410\_GPC10\_OUTP   
 \#define  LCD\_DATA\_CFG3\_OUTP S3C2410\_GPC11\_OUTP   
  
 \#define  LCD\_DATA\_CFG4\_OUTP S3C2410\_GPC12\_OUTP   
 \#define  LCD\_DATA\_CFG5\_OUTP S3C2410\_GPC13\_OUTP   
 \#define  LCD\_DATA\_CFG6\_OUTP S3C2410\_GPC14\_OUTP   
 \#define  LCD\_DATA\_CFG7\_OUTP S3C2410\_GPC15\_OUTP   
  
  
 \#define  LCD\_E\_RD\_CFG\_OUTP S3C2410\_GPD0\_OUTP   
 \#define  LCD\_RW\_WR\_CFG\_OUTP S3C2410\_GPD1\_OUTP   
 \#define  LCD\_RS\_CFG\_OUTP S3C2410\_GPD2\_OUTP   
 \#define  LCD\_RES\_CFG\_OUTP S3C2410\_GPD3\_OUTP   
 \#define  LCD\_CS1\_CFG\_OUTP S3C2410\_GPD4\_OUTP   
 \#define  LCD\_BL\_CFG\_OUTP S3C2410\_GPD5\_OUTP   
  
  
 \#define  FONT\_SIZE\_8 8   
 \#define  FONT\_SIZE\_16 16   
  
  
 \#endif

将引脚单独用头文件重新自己定义一次，以提高代码的可移植性。

下面看看模块初始化/释放函数：

static  int  \_\_init lcd12864\_init( void )  
\{  
 int  ret;  
dev\_t devno;  
  
DBPRINTF(KERN\_ALERT  " %s enter!\\n " ,\_\_func\_\_);  
devno  =  MKDEV(lcd12864\_major, 0 );  
 if ((ret  =  register\_chrdev\_region(devno, 1 ,DEV\_NAME)) < 0 )  
\{  
 if ((ret  =  alloc\_chrdev\_region( & devno,  0 ,  1 , DEV\_NAME)) < 0 )  
\{  
DBPRINTF(KERN\_ALERT  " chrdev region fail!ret=%d;\\n " ,ret);  
 return  ret;  
\}  
 else   
\{  
lcd12864\_major  =  MAJOR(devno);  
\}  
\}  
cdev\_init( & lcd\_cdev,  & lcd12864\_ops);  
lcd\_cdev.owner = THIS\_MODULE;  
lcd\_cdev.ops  =  & lcd12864\_ops;  
  
ret  =  cdev\_add( & lcd\_cdev, devno,  1 );  
 if (ret < 0 )  
\{  
 goto  fail\_reg;  
\}  
  
lcd\_dev\_class  =  class\_create(THIS\_MODULE, DEV\_NAME);  
 if (IS\_ERR(lcd\_dev\_class))  
\{  
 goto  fail\_cdev;  
\}  
device\_create(lcd\_dev\_class, NULL, devno, NULL, DEV\_NAME);  
  
lcd\_bd\_info  =  kmalloc( sizeof ( struct  lcd\_board\_info),GFP\_KERNEL);  
lcd\_bd\_info \-> font\_size  =  16 ;  
  
\#ifdef NORMAL  
lcd\_bd\_info \-> pag  =  0 ;  
lcd\_bd\_info \-> column  =  0 ;  
 \#else   
lcd\_bd\_info \-> pag  =  6 ;  
lcd\_bd\_info \-> column  =  112 ;  
 \#endif   
lcd\_bd\_info \-> lcd\_data\_t  =  lcd\_data\_table;  
lcd\_bd\_info \-> lcd\_data\_cfg\_t  =  lcd\_data\_cfg\_table;  
  
spin\_lock\_init( & lock );  
  
gpio\_pin\_init();  
 // gpio\_pin\_init();   
   
  
ret  =  init\_lcd12864();  
 if (ret < 0 )  
\{  
 goto  fail\_dev;  
\}  
back\_light\_ctrl( 1 );  
clear\_lcd\_screen( 0x00 );  
DBPRINTF(KERN\_ALERT  " %s leave,init success!\\n " ,\_\_func\_\_);  
 return  ret;  
  
fail\_dev:  
device\_destroy(lcd\_dev\_class, devno);  
class\_destroy(lcd\_dev\_class);  
  
fail\_cdev:  
cdev\_del( & lcd\_cdev);  
fail\_reg:  
unregister\_chrdev\_region(devno,  1 );  
 return  ret;  
\}  
  
  
 static  void  \_\_exit lcd12864\_exit( void )  
\{  
kfree(lcd\_bd\_info);  
device\_destroy(lcd\_dev\_class, MKDEV(lcd12864\_major,  0 ));  
class\_destroy(lcd\_dev\_class);  
cdev\_del( & lcd\_cdev);  
unregister\_chrdev\_region(MKDEV(lcd12864\_major,  0 ),  1 );  
\}  
  
module\_init(lcd12864\_init);  
module\_exit(lcd12864\_exit);  
  
MODULE\_LICENSE( " GPL " );  
MODULE\_AUTHOR( " HOY " );  
MODULE\_DESCRIPTION( " gonsin 128x64 lcd driver " );

以上主要工作是：通过register\_chrdev\_region静态分配设备号devno,如果分配失败，则通过系统alloc\_chrdev\_region动态分配；

此处通过cdev创建字符设备;通过cdev\_add添加入系统中。通过class\_create和device\_create生成并注册一个逻辑设备，通过此工作，可以在/dev/下面看到设备名；

初始化lcd\_board\_info结构，lcd\_board\_info结构定义如下：

struct  lcd\_board\_info\{  
  
unsigned  int  font\_size;  
unsigned  int  pag;  
unsigned  int  column;  
unsigned  long \*  lcd\_data\_t;  
unsigned  long \*  lcd\_data\_cfg\_t;  
\};  
  
 static  struct  lcd\_board\_info \*  lcd\_bd\_info;

其他变量和头文件定义如下：

\#include  < linux / fs.h >   
\#include  < linux / module.h >   
\#include  < linux / init.h >   
\#include  < mach / regs \- gpio.h >   
\#include  < linux / ioctl.h >   
\#include  < linux / cdev.h >   
\#include  < linux / slab.h >   
\#include  < linux / uaccess.h >   
\#include  < linux / device.h >   
\#include  < asm / io.h >   
\#include  < linux / delay.h >   
  
 \#define  DEBUG  // 调试状态   
\#ifdef DEBUG  
 \#define  DBPRINTF(fmt,args...) printk(KERN\_ALERT "lcd:" fmt, \#\#args)   
 \#else   
 \#define  DBPRINTF(fmt,args...)   
 \#endif   
  
\#include  " lcd\_12864.h "   
  
 \#define  NORMAL  // 正常模式   
  
  
 static  struct  class \*  lcd\_dev\_class;  
  
 struct  cdev lcd\_cdev;  
  
 static  int  lcd12864\_major  =  LCD12864\_MAJOR;  
  
 static  unsigned  long  lcd\_data\_table\[\] = \{  
LCD\_DATA\_0,  
LCD\_DATA\_1,  
LCD\_DATA\_2,  
LCD\_DATA\_3,  
  
LCD\_DATA\_4,  
LCD\_DATA\_5,  
LCD\_DATA\_6,  
LCD\_DATA\_7,  
\};  
  
 /\*\*/   
 static  unsigned  long  lcd\_data\_cfg\_table\[\]  =   
\{  
LCD\_DATA\_CFG0\_OUTP,  
LCD\_DATA\_CFG1\_OUTP,  
LCD\_DATA\_CFG2\_OUTP,  
LCD\_DATA\_CFG3\_OUTP,  
  
LCD\_DATA\_CFG4\_OUTP,  
LCD\_DATA\_CFG5\_OUTP,  
LCD\_DATA\_CFG6\_OUTP,  
LCD\_DATA\_CFG7\_OUTP,  
\};  
  
 /\*   
static unsigned char io\_read\_byte()  
\{  
  
\}  
 \*/   
spinlock\_t  lock ;

然后调用以下函数进行gpio引脚的初始化、液晶屏的初始化：

static  int  gpio\_pin\_init( void )  
\{  
  
 int  ii;  
s3c2410\_gpio\_cfgpin(LCD\_CS1, LCD\_CS1\_CFG\_OUTP);  
s3c2410\_gpio\_cfgpin(LCD\_RES, LCD\_RES\_CFG\_OUTP);  
s3c2410\_gpio\_cfgpin(LCD\_RS, LCD\_RS\_CFG\_OUTP);  
s3c2410\_gpio\_cfgpin(LCD\_RW\_WR, LCD\_RW\_WR\_CFG\_OUTP);  
s3c2410\_gpio\_cfgpin(LCD\_E\_RD, LCD\_E\_RD\_CFG\_OUTP);  
s3c2410\_gpio\_cfgpin(LCD\_BL, LCD\_BL\_CFG\_OUTP);  
  
 for (ii = 0 ; ii < 8 ; ii \++ )  
\{  
s3c2410\_gpio\_cfgpin(lcd\_bd\_info \-> lcd\_data\_t\[ii\], lcd\_bd\_info \-> lcd\_data\_cfg\_t\[ii\]);  
\}  
 return  0 ;  
\}  
  
  
 static  unsigned  char  init\_cmd\[\] = \{  
 0xe2 ,  
 0xa0 ,  
 0xc0 ,  
 0xA2 ,  
 0x2B ,  
 0x2E ,  
 0x2F ,  
 0x27 ,  
 0xAF ,  
 0 ,  
\};  
  
  
 static  int  init\_lcd12864( void )  
\{  
  
 int  ii;  
s3c2410\_gpio\_setpin(LCD\_CS1,  0 );  
udelay( 500 );  
s3c2410\_gpio\_setpin(LCD\_RES,  0 );  
udelay( 500 );  
s3c2410\_gpio\_setpin(LCD\_RES,  1 );  
udelay( 500 );  
  
 for (ii = 0 ;init\_cmd\[ii\] != 0 ;ii \++ )  
\{  
send\_cmd(init\_cmd\[ii\]);  
udelay( 50 );  
\}  
 return  0 ;  
\}

以下为写液晶屏和写命令的操作：

\#ifdef NORMAL  
 /\* 往液晶中写入1个字符数据 \*/   
 static  void  io\_write\_byte(unsigned  char  data)  
\{  
unsigned  char  ii;  
spin\_lock( & lock );  
  
 for (ii = 0 ;ii < 8 ;ii \++ )  
\{  
 if (data & 0b1)  
\{  
s3c2410\_gpio\_setpin(lcd\_bd\_info \-> lcd\_data\_t\[ii\],  1 );  
\}  
 else   
\{  
s3c2410\_gpio\_setpin(lcd\_bd\_info \-> lcd\_data\_t\[ii\],  0 );  
\}  
data  =  data >> 1 ;  
\}  
 // \_\_raw\_writel(((\_\_raw\_readl(S3C2410\_GPCDAT)&~(0xff<<8))|(data<<8)),S3C2410\_GPCDAT);   
   
spin\_unlock( & lock );  
  
s3c2410\_gpio\_setpin(LCD\_RS,  1 );  
s3c2410\_gpio\_setpin(LCD\_RW\_WR,  0 );  
s3c2410\_gpio\_setpin(LCD\_E\_RD,  1 );  
s3c2410\_gpio\_setpin(LCD\_CS1,  1 );  
udelay( 1 );  
s3c2410\_gpio\_setpin(LCD\_CS1,  0 );  
udelay( 1 );  
  
\}  
 \#else   
 static  void  io\_write\_byte(unsigned  char  data)  
\{  
unsigned  char  ii;  
spin\_lock( & lock );  
 for (ii = 0 ;ii < 8 ;ii \++ )  
\{  
 if (data & 0x80 )  
\{  
 // DBPRINTF(KERN\_ALERT "\[||||||||||||||||||||\]\\n");   
 s3c2410\_gpio\_setpin(lcd\_bd\_info \-> lcd\_data\_t\[ii\],  1 );  
\}  
 else   
\{  
 // DBPRINTF(KERN\_ALERT "\[--------------------\]\\n");   
 s3c2410\_gpio\_setpin(lcd\_bd\_info \-> lcd\_data\_t\[ii\],  0 );  
\}  
data  =  data << 1 ;  
\}  
spin\_unlock( & lock );  
 // DBPRINTF(KERN\_ALERT "\\n");   
   
s3c2410\_gpio\_setpin(LCD\_RS,  1 );  
s3c2410\_gpio\_setpin(LCD\_RW\_WR,  0 );  
s3c2410\_gpio\_setpin(LCD\_E\_RD,  1 );  
  
s3c2410\_gpio\_setpin(LCD\_CS1,  1 );  
udelay( 1 );  
s3c2410\_gpio\_setpin(LCD\_CS1,  0 );  
udelay( 1 );  
\}  
 \#endif   
  
 // 发送命令   
 static  int  send\_cmd(unsigned  char  cmd)  
\{  
 int  ii;  
unsigned  char  tmp;  
tmp  =  0x00 ;  
spin\_lock( & lock );  
  
 for (ii = 0 ;ii < 8 ;ii \++ )  
\{  
 if (cmd & 0x80 )  
\{  
s3c2410\_gpio\_setpin(lcd\_bd\_info \-> lcd\_data\_t\[ii\],  1 );  
\}  
 else   
\{  
s3c2410\_gpio\_setpin(lcd\_bd\_info \-> lcd\_data\_t\[ii\],  0 );  
\}  
cmd  =  cmd << 1 ;  
\}  
 /\* \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* \*/   
 /\*   
for(ii=0;ii<8;ii++)  
\{  
tmp = tmp<<1;  
if(cmd&0b1)  
\{  
tmp|=0b1;  
\}  
else  
\{  
tmp &= 0b0;  
\}  
cmd = cmd>>1;  
  
\}  
\_\_raw\_writel(((\_\_raw\_readl(S3C2410\_GPCDAT)&~(0xff<<8))|(tmp<<8)),S3C2410\_GPCDAT); \*/   
 /\* \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* \*/   
  
spin\_unlock( & lock );  
  
  
s3c2410\_gpio\_setpin(LCD\_RS,  0 );  
s3c2410\_gpio\_setpin(LCD\_RW\_WR,  0 );  
s3c2410\_gpio\_setpin(LCD\_E\_RD,  1 );  
s3c2410\_gpio\_setpin(LCD\_CS1,  1 );  
udelay( 1 );  
  
s3c2410\_gpio\_setpin(LCD\_CS1,  0 );  
udelay( 1 );  
 return  0 ;  
\}  
  
  
  
 static  int  dev\_write\_data( const  char \*  data)  
\{  
unsigned  char  dl,dh;  
 int  i,j;  
spin\_lock( & lock );  
dh  =  lcd\_bd\_info \-> column / 16 ;  
dl  =  lcd\_bd\_info \-> column \- dh \* 16 ;  
 for (i = 0 ; i < 2 ; i \++ )  
\{  
send\_cmd( 0xB7 \- i \- lcd\_bd\_info \-> pag);  
send\_cmd( 0x10 \+ dh);  
send\_cmd(dl);  
  
\#ifdef NORMAL  
 for (j = 0 ;j < 16 ;j \++ )  
io\_write\_byte(data\[lcd\_bd\_info \-> font\_size \* i \+ j\]);  
 \#else   
 for (j = 0 ;j < 16 ;j \++ )  
io\_write\_byte(data\[lcd\_bd\_info \-> font\_size \* ( 1 \- i) \+ ( 15 \- j)\]);  
 \#endif   
\}  
spin\_unlock( & lock );  
 return  0 ;  
\}

因为公司结构方面的需要，要将液晶倒转显示，所以此处做了两个不同的方案，如果定义了NORMAL,则正常显示，否则倒转显示;

其他对液晶屏控制的操作如下：

/\* 清除屏幕 \*/   
 static  void  clear\_lcd\_screen(unsigned  char  clr\_data)  
\{  
unsigned  char  page\_addr  =  0xb7 ;  
unsigned  int  page\_num;  
 int  ii;  
 for (page\_num = 0 ; page\_num < 8 ; page\_num \++ )  
\{  
send\_cmd(page\_addr);  
send\_cmd( 0x10 );  
send\_cmd( 0x00 );  
 for (ii = 0 ; ii < 128 ; ii \++ )  
io\_write\_byte(clr\_data);  
page\_addr \-- ;  
\}  
\}  
  
 static  int  lcd12864\_open( struct  inode \*  inode,  struct  file \*  filp)  
\{  
 return  0 ;  
\}  
  
 static  int  lcd12864\_release( struct  inode \*  inode,  struct  file \*  filp)  
\{  
 return  0 ;  
\}  
  
 static  ssize\_t lcd12864\_write( struct  file \*  filp,  char  \_\_user \*  buf, size\_t size, loff\_t offset)  
\{  
 char \*  kbuf;  
 //  int count;   
   
kbuf  =  kmalloc(size, GFP\_KERNEL);  
copy\_from\_user(kbuf, buf, size);  
dev\_write\_data(kbuf);  
  
kfree(kbuf);  
 return  0 ;  
\}  
  
 static  int  contrast\_setting( int  val)  
\{  
 if ((val & 0xff ) > 0x3e )  
 return  \- 1 ;  
send\_cmd( 0x81 );  
send\_cmd(val & 0xff );  
DBPRINTF(KERN\_ALERT  " contrast setting,val is%d\\n " ,val);  
 return  0 ;  
\}  
 /\* 背光控制 \*/   
 static  int  back\_light\_ctrl( int  bl)  
\{  
 if (bl < 0 )  
\{  
 return  \- 1 ;  
\}  
 else  if (bl == 0 )  
\{  
s3c2410\_gpio\_setpin(LCD\_BL,  0 );  
DBPRINTF(KERN\_ALERT  " back light set value is 0\\n " );  
\}  
 else   
\{  
s3c2410\_gpio\_setpin(LCD\_BL,  1 );  
DBPRINTF(KERN\_ALERT  " back light set value is 1\\n " );  
\}  
 return  0 ;  
\}  
  
 static  int  lcd12864\_ioctl( struct  inode \*  inode, struct  file \*  filp, unsigned  int  cmd, unsigned  long  args)  
\{  
 int  ret;  
spin\_lock( & lock );  
ret  =  0 ;  
DBPRINTF(KERN\_ALERT  " %s " ,\_\_func\_\_);  
 switch (cmd)  
\{  
 case  SET\_FONT\_SIZE:  
\{  
 int  size  =  \* ( int \* )args;  
 if (size  ==  FONT\_SIZE\_8 || size  ==  FONT\_SIZE\_16)  
\{  
lcd\_bd\_info \-> font\_size  =  size;  
\}  
 else   
\{  
ret  =  \- 1 ;  
DBPRINTF(KERN\_ALERT  " set font size fail!\\n " );  
 goto  ioctl\_fail;  
\}  
 break ;  
\}  
 case  SET\_LCD\_PAGE:  
\{  
 int  tmp  =  \* ( int \* )args;  
 if (tmp > 63 )  
 return  \- 1 ;  
  
  
\#ifdef NORMAL  
lcd\_bd\_info \-> pag  =  tmp;  
 \#else   
lcd\_bd\_info \-> pag  =  6 \- tmp;  
 \#endif   
DBPRINTF(KERN\_ALERT  " set pag is %d\\n " ,lcd\_bd\_info \-> pag);  
 break ;  
\}  
 case  SET\_LCD\_COLUMN:  
\{  
 int  tmp  =  \* ( int \* )args;  
 if (tmp > 127 )  
 return  \- 1 ;  
\#ifdef NORMAL  
lcd\_bd\_info \-> column  = tmp;  
 \#else   
lcd\_bd\_info \-> column  = 112 \- tmp;  
 \#endif   
DBPRINTF(KERN\_ALERT  " set column is %d\\n " ,lcd\_bd\_info \-> column);  
 break ;  
\}  
 case  CLR\_SCREEN:  
\{  
unsigned  char  data  =  \* ( char \* )args;  
clear\_lcd\_screen(data);  
 break ;  
\}  
 case  BACKLIGHT\_CTRL:  
\{  
 int  bl  =  \* ( int \* )args;  
ret  =  back\_light\_ctrl(bl);  
 break ;  
\}  
 case  CONTRAST\_SETTING:  
\{  
 int  con  =  \* ( int \* )args;  
ret  =  contrast\_setting(con);  
 break ;  
\}  
  
\}  
spin\_unlock( & lock );  
 return  ret;  
ioctl\_fail:  
spin\_unlock( & lock );  
 return  ret;  
\}

最后看看file\_operations结构体：

static  struct  file\_operations lcd12864\_ops = \{  
.owner  =  THIS\_MODULE,  
.open  =  lcd12864\_open,  
.release  =  lcd12864\_release,  
.write  =  lcd12864\_write,  
 // .read = lcd12864\_read,   
 .ioctl  =  lcd12864\_ioctl,  
\};

以上则是液晶屏的驱动程序，很简单吧？哈哈~~

Makefile如下所示：

obj \- m: = lcd\_12864.o  
KDIR =/ home / project / linux \- res / linux \- 2.6 . 30.4 /   
  
all:  
$(MAKE)  \- C $(KDIR) M = $(PWD)  
  
.PHONY:clean  
clean:  
rm  \- f  \* .o  \* .ko  \* .mod.c  \* .mod.o  \* .tmp\_versions

最后是液晶屏测试程序：

enum  \{  
FONT\_SIZE8,  
FONT\_SIZE16,  
FONT\_SIZE32,  
\};  
  
  
 /\* 将字符数组里面的每一位取反 \*/   
 void  oppersite( const  char \*  cin, \_\_out  char \*  cout, int  len)  
\{  
 int  i = 0 ;  
  
 for (i = 0 ;i < len;i \++ )  
\{  
cout\[i\] =~ cin\[i\];  
\}  
\}  
  
 /\* 由size\_flag 解析出字体大小 \*/   
 int  prase\_size\_flag( int  size\_flag)  
\{  
 int  fsize;  
 switch (size\_flag)  
\{  
 case  FONT\_SIZE8:  
fsize  =  8 ;  
 break ;  
 case  FONT\_SIZE16:  
fsize  =  16 ;  
 break ;  
 case  FONT\_SIZE32:  
fsize  =  32 ;  
 break ;  
 default :  
printf( " size\_flag is involid!\\n " );  
 return  \- 1 ;  
\}  
 return  fsize;  
\}  
  
 int  prase\_row( int  pag)  
\{  
 return  pag \* 2 ;  
\}  
  
 int  prase\_column( int  col)  
\{  
 return  col \* 16 ;  
\}  
  
 /\* 显示一个选中的字符  
ch:字符的16进制数组  
pag:第几页;0-7  
col:第几列;0-127  
size\_flag:字体枚举  
 \*/   
 int  show\_select\_ch( int  fd,  const  char \*  ch,  int  pag,  int  col,  int  size\_flag)  
\{  
 char  chtmp\[ 50 \];  
 int  fsize;  
  
 if ( ! ch)  
 return  \- 1 ;  
  
 if ((fsize = prase\_size\_flag(size\_flag)) < 0 )  
 return  \- 1 ;  
  
 int  size  =  fsize \* fsize / 8 ;  
oppersite(ch, chtmp, size);  
 if (ioctl(fd, SET\_LCD\_PAGE,  & pag) < 0 )  
 return  \- 1 ;  
 if (ioctl(fd, SET\_LCD\_COLUMN,  & col) < 0 )  
 return  \- 1 ;  
 if (write(fd, chtmp, size) < 0 )  
 return  \- 1 ;  
 return  0 ;  
\}  
 /\* 显示一个字符  
ch:字符的16进制数组  
pag:第几页;0-7  
col:第几列;0-127  
size\_flag:字体枚举  
 \*/   
 int  show\_ch( int  fd,  const  char \*  ch,  int  pag,  int  col,  int  size\_flag)  
\{  
 if ( ! ch)  
 return  \- 1 ;  
  
 int  fsize;  
 if ((fsize = prase\_size\_flag(size\_flag)) < 0 )  
 return  \- 1 ;  
  
 int  size  =  fsize \* fsize / 8 ;  
 if (ioctl(fd, SET\_LCD\_PAGE,  & pag) < 0 )  
 return  \- 1 ;  
 if (ioctl(fd, SET\_LCD\_COLUMN,  & col) < 0 )  
 return  \- 1 ;  
 if (write(fd, ch, size) < 0 )  
 return  \- 1 ;  
 return  0 ;  
\}  
  
 /\* 显示一行字符串 \*/   
 int  show\_str( int  fd,  const  char \*\*  str,  int  count,  int  pag,  int  col,  int  size\_flag)  
\{  
 int  fsize;  
 int  i;  
 if ((fsize = prase\_size\_flag(size\_flag)) < 0 )  
 return  \- 1 ;  
  
 for (i = 0 ; i < count; i \++ )  
\{  
 if (pag < PAGE\_COUNT  &&  col < COLUMN\_COUNT)  
\{  
 if (show\_ch(fd, str\[i\], pag, col, size\_flag) < 0 )  
 return  \- 1 ;  
col \+= fsize;  
\}  
\}  
 return  0 ;  
\}  
  
 /\* 显示一行选中的字符串 \*/   
 int  show\_select\_str( int  fd,  const  char \*\*  str,  int  count,  int  pag,  int  col,  int  size\_flag)  
\{  
 int  fsize;  
 int  i;  
 if ((fsize = prase\_size\_flag(size\_flag)) < 0 )  
 return  \- 1 ;  
  
 for (i = 0 ; i < count; i \++ )  
\{  
 if (pag < PAGE\_COUNT  &&  col < COLUMN\_COUNT)  
\{  
 if (show\_select\_ch(fd, str\[i\], pag, col, size\_flag) < 0 )  
 return  \- 1 ;  
col \+= fsize;  
\}  
\}  
 return  0 ;  
\}  
  
 /\* 对比度调节0-62 \*/   
 int  contrast\_ctrl( int  fd,  int  val)  
\{  
 if (ioctl(fd,CONTRAST\_SETTING, & val) < 0 )  
 return  \- 1 ;  
 return  0 ;  
\}  
  
 /\* 背光调节 1:亮，0:灭 \*/   
 int  backlight\_ctrl( int  fd, int  val)  
\{  
 if (ioctl(fd, BACKLIGHT\_CTRL,  & val) < 0 )  
 return  \- 1 ;  
 return  0 ;  
\}  
  
 /\* 清屏 \*/   
 int  clear\_screen( int  fd,  int  val)  
\{  
 if (ioctl(fd, CLR\_SCREEN,  & val) < 0 )  
 return  \- 1 ;  
 return  0 ;  
\}  
  
  
 /\* 字体大小 \*/   
 int  font\_size( int  fd,  int  val)  
\{  
 if (ioctl(fd, SET\_FONT\_SIZE,  & val) < 0 )  
 return  \- 1 ;  
 return  0 ;  
\}

int  main( void )  
\{  
fd  =  open(LCD\_DEV\_NAME,O\_RDWR);  
show\_ch(fd, zi,  0 ,  0 ,  1 );  
show\_select\_ch(fd, zi,  0 ,  32 ,  1 );  
show\_str(fd, tmp,  8 ,  2 ,  0 ,  1 );  
show\_select\_str(fd, tmp,  8 ,  4 ,  0 ,  1 );  
close(fd);  
\}

[Link 1]: http://www.cnblogs.cc2/view/545607.htm