?? linux設(shè)備驅(qū)動(dòng)程序?qū)W習(xí)（1）-字符設(shè)備驅(qū)動(dòng)程序 - linux設(shè)備驅(qū)動(dòng)程序 - tekkaman ninja.htm
字號(hào):
cdev</SPAN></SPAN></FONT><FONT
style="COLOR: rgb(255,1,2)" size=3><SPAN
style="COLOR: rgb(0,1,2)">。代碼應(yīng)包含</SPAN></FONT><FONT
size=3><SPAN
style="FONT-WEIGHT: normal; COLOR: rgb(0,1,2)"><SPAN
style="COLOR: rgb(0,1,255)"><linux/cdev.h></SPAN></SPAN></FONT><FONT
style="COLOR: rgb(255,1,2)" size=3><SPAN
style="COLOR: rgb(0,1,2)">，它定義了</SPAN></FONT><FONT
style="COLOR: rgb(255,1,2)" size=3><SPAN
style="COLOR: rgb(0,1,2)"><SPAN
style="COLOR: rgb(0,1,255)">struct
cdev</SPAN></SPAN></FONT><FONT
style="COLOR: rgb(255,1,2)" size=3><SPAN
style="COLOR: rgb(0,1,2)">以及與其相關(guān)的一些輔助函數(shù)。</SPAN></FONT></P>
<P align=center><FONT
style="COLOR: rgb(255,1,2)"><SPAN
style="COLOR: rgb(0,1,2)"><FONT color=#0000ff
size=3><STRONG>注冊(cè)一個(gè)獨(dú)立的cdev設(shè)備的基本過(guò)程如下：</STRONG></FONT></SPAN></FONT></P><FONT
style="COLOR: rgb(255,1,2)"></FONT>
<P align=left><FONT
style="COLOR: rgb(255,1,2)"><FONT face=楷體
color=#0000ff size=3>1、為struct cdev
分配空間(如果已經(jīng)將struct cdev
嵌入到自己的設(shè)備的特定結(jié)構(gòu)體中，并分配了空間，這步略過(guò)！)</FONT></FONT></P>
<P align=left><FONT
style="COLOR: rgb(255,1,2)"><FONT face=楷體
color=#000000>struct cdev *my_cdev =
cdev_alloc();</FONT></FONT></P>
<P><FONT style="COLOR: rgb(255,1,2)"><FONT face=楷體
color=#0000ff size=3>2、初始化struct cdev
</FONT></FONT></P><FONT
style="COLOR: rgb(255,1,2)"><FONT color=#000000
size=2>void cdev_init(struct cdev *cdev, const
struct file_operations *fops)</FONT> </FONT>
<P><FONT style="COLOR: rgb(255,1,2)"><FONT face=楷體
color=#0000ff
size=3>3、初始化cdev.owner</FONT></FONT></P>
<P><FONT style="COLOR: rgb(255,1,2)"><FONT
color=#000000>cdev.owner =
THIS_MODULE;</FONT></FONT></P>
<P><FONT style="COLOR: rgb(255,1,2)"><FONT
size=3><FONT face=楷體
color=#0000ff>4、cdev設(shè)置完成，通知內(nèi)核struct cdev的信息（<FONT
color=#ff0000>在執(zhí)行這步之前必須確定你對(duì)<FONT size=2>struct
cdev</FONT></FONT><FONT size=3><FONT
color=#ff0000>的以上設(shè)置已經(jīng)完成！</FONT>）</FONT></FONT></FONT></FONT></P>
<P><FONT style="COLOR: rgb(255,1,2)"><FONT
color=#000000>int cdev_add(struct cdev *p, dev_t
dev, unsigned count)</FONT></FONT></P>
<P><FONT style="COLOR: rgb(255,1,2)"><FONT
color=#0000ff size=3>從系統(tǒng)中移除一個(gè)字符設(shè)備：<FONT
color=#000000 size=2>void cdev_del(struct cdev
*p)</FONT></FONT></FONT></P>
<P><FONT style="COLOR: rgb(255,1,2)"><FONT
size=3><FONT color=#000000></FONT><FONT
color=#0000ff>以下是scull中的初始化代碼（之前已經(jīng)為<FONT
size=2><FONT face=新宋體><FONT color=#000000><FONT
color=#000000><SPAN
style="COLOR: rgb(0,0,255)"><FONT
color=#000000>struct</FONT></SPAN>
</FONT>scull_dev</FONT> <FONT
size=3>分配了空間</FONT></FONT></FONT>）：</FONT></FONT></FONT></P>
<TABLE style="BORDER-COLLAPSE: collapse"
borderColor=#999999 cellSpacing=0 cellPadding=0
width="95%" bgColor=#f1f1f1 border=1>
<TBODY>
<TR>
<TD>
<P
style="MARGIN: 5px; LINE-HEIGHT: 150%"><CODE><SPAN
style="COLOR: rgb(0,0,0)"><SPAN
style="COLOR: rgb(255,153,0)">/*<BR> * Set
up the char_dev structure for this
device.<BR> */</SPAN><BR><SPAN
style="COLOR: rgb(0,0,255)">static</SPAN> <SPAN
style="COLOR: rgb(0,0,255)">void</SPAN>
scull_setup_cdev<SPAN
style="COLOR: rgb(0,0,204)">(</SPAN><SPAN
style="COLOR: rgb(0,0,255)">struct</SPAN>
scull_dev <SPAN
style="COLOR: rgb(0,0,204)">*</SPAN>dev<SPAN
style="COLOR: rgb(0,0,204)">,</SPAN> <SPAN
style="COLOR: rgb(0,0,255)">int</SPAN>
index<SPAN
style="COLOR: rgb(0,0,204)">)</SPAN><BR><SPAN
style="COLOR: rgb(0,0,204)">{</SPAN><BR> <SPAN
style="COLOR: rgb(0,0,255)">int</SPAN> err<SPAN
style="COLOR: rgb(0,0,204)">,</SPAN> devno <SPAN
style="COLOR: rgb(0,0,204)">=</SPAN> MKDEV<SPAN
style="COLOR: rgb(0,0,204)">(</SPAN>scull_major<SPAN
style="COLOR: rgb(0,0,204)">,</SPAN> scull_minor
<SPAN style="COLOR: rgb(0,0,204)">+</SPAN>
index<SPAN
style="COLOR: rgb(0,0,204)">)</SPAN><SPAN
style="COLOR: rgb(0,0,204)">;</SPAN><BR> <BR> cdev_init<SPAN
style="COLOR: rgb(0,0,204)">(</SPAN><SPAN
style="COLOR: rgb(0,0,204)">&</SPAN>dev<SPAN
style="COLOR: rgb(0,0,204)">-</SPAN><SPAN
style="COLOR: rgb(0,0,204)">></SPAN>cdev<SPAN
style="COLOR: rgb(0,0,204)">,</SPAN> <SPAN
style="COLOR: rgb(0,0,204)">&</SPAN>scull_fops<SPAN
style="COLOR: rgb(0,0,204)">)</SPAN><SPAN
style="COLOR: rgb(0,0,204)">;</SPAN><BR> dev<SPAN
style="COLOR: rgb(0,0,204)">-</SPAN><SPAN
style="COLOR: rgb(0,0,204)">></SPAN>cdev<SPAN
style="COLOR: rgb(0,0,204)">.</SPAN>owner <SPAN
style="COLOR: rgb(0,0,204)">=</SPAN>
THIS_MODULE<SPAN
style="COLOR: rgb(0,0,204)">;</SPAN><BR> dev<SPAN
style="COLOR: rgb(0,0,204)">-</SPAN><SPAN
style="COLOR: rgb(0,0,204)">></SPAN>cdev<SPAN
style="COLOR: rgb(0,0,204)">.</SPAN>ops <SPAN
style="COLOR: rgb(0,0,204)">=</SPAN> <SPAN
style="COLOR: rgb(0,0,204)">&</SPAN>scull_fops<SPAN
style="COLOR: rgb(0,0,204)">; </SPAN></SPAN></CODE><CODE><SPAN
style="COLOR: rgb(0,0,0)"><SPAN
style="COLOR: rgb(0,0,204)"> <FONT
color=#ff0000>//這句可以省略，在<FONT face=新宋體><FONT
color=#000000>cdev_init</FONT>中已經(jīng)做過(guò)</FONT></FONT></SPAN><BR> err
<SPAN style="COLOR: rgb(0,0,204)">=</SPAN>
cdev_add <SPAN
style="COLOR: rgb(0,0,204)">(</SPAN><SPAN
style="COLOR: rgb(0,0,204)">&</SPAN>dev<SPAN
style="COLOR: rgb(0,0,204)">-</SPAN><SPAN
style="COLOR: rgb(0,0,204)">></SPAN>cdev<SPAN
style="COLOR: rgb(0,0,204)">,</SPAN> devno<SPAN
style="COLOR: rgb(0,0,204)">,</SPAN> 1<SPAN
style="COLOR: rgb(0,0,204)">)</SPAN><SPAN
style="COLOR: rgb(0,0,204)">;</SPAN><BR> <SPAN
style="COLOR: rgb(255,153,0)">/* Fail gracefully
if need be <FONT
color=#ff0000>這步值得注意</FONT>*/</SPAN><BR> <SPAN
style="COLOR: rgb(0,0,255)">if</SPAN> <SPAN
style="COLOR: rgb(0,0,204)">(</SPAN>err<SPAN
style="COLOR: rgb(0,0,204)">)</SPAN><BR> printk<SPAN
style="COLOR: rgb(0,0,204)">(</SPAN>KERN_NOTICE
<SPAN style="COLOR: rgb(255,0,255)">"Error %d
adding scull%d"</SPAN><SPAN
style="COLOR: rgb(0,0,204)">,</SPAN> err<SPAN
style="COLOR: rgb(0,0,204)">,</SPAN> index<SPAN
style="COLOR: rgb(0,0,204)">)</SPAN><SPAN
style="COLOR: rgb(0,0,204)">;</SPAN><BR><SPAN
style="COLOR: rgb(0,0,204)">}</SPAN></SPAN></CODE></P></TD></TR></TBODY></TABLE><FONT
color=#0001ff size=4></FONT>
<P></P>
<HR id=null>
<FONT color=#0001ff size=4><FONT
size=4>四、scull模型的內(nèi)存使用</FONT> </FONT>
<P></P>
<P><FONT color=#0001ff size=4><IMG
src="Linux設(shè)備驅(qū)動(dòng)程序?qū)W習(xí)（1）-字符設(shè)備驅(qū)動(dòng)程序 - Linux設(shè)備驅(qū)動(dòng)程序 - Tekkaman Ninja.files/071024144610.jpg"></FONT></P>
<P><FONT color=#0001ff size=4><FONT
size=3>以下是scull模型的結(jié)構(gòu)體：</FONT></FONT></P>
<DIV></DIV>
<DIV></DIV>
<TABLE style="BORDER-COLLAPSE: collapse"
borderColor=#999999 cellSpacing=0 cellPadding=0
width="95%" bgColor=#f1f1f1 border=1>
<TBODY>
<TR>
<TD>
<P
style="MARGIN: 5px; LINE-HEIGHT: 150%"><CODE><SPAN
style="COLOR: rgb(0,0,0)"><SPAN
style="COLOR: rgb(255,153,0)">/*<BR> *
Representation of scull quantum
sets.<BR> */</SPAN><BR><SPAN
style="COLOR: rgb(0,0,255)">struct</SPAN>
scull_qset <SPAN
style="COLOR: rgb(0,0,204)">{</SPAN><BR> <SPAN
style="COLOR: rgb(0,0,255)">void</SPAN> <SPAN
style="COLOR: rgb(0,0,204)">*</SPAN><SPAN
style="COLOR: rgb(0,0,204)">*</SPAN>data<SPAN
style="COLOR: rgb(0,0,204)">;</SPAN><BR> <SPAN
style="COLOR: rgb(0,0,255)">struct</SPAN>
scull_qset <SPAN
style="COLOR: rgb(0,0,204)">*</SPAN>next<SPAN
style="COLOR: rgb(0,0,204)">;</SPAN><BR><SPAN
style="COLOR: rgb(0,0,204)">}</SPAN><SPAN
style="COLOR: rgb(0,0,204)">;</SPAN><BR><BR><SPAN
style="COLOR: rgb(0,0,255)">struct</SPAN>
scull_dev <SPAN
style="COLOR: rgb(0,0,204)">{</SPAN><BR> <SPAN
style="COLOR: rgb(0,0,255)">struct</SPAN>
scull_qset <SPAN
style="COLOR: rgb(0,0,204)">*</SPAN>data<SPAN
style="COLOR: rgb(0,0,204)">;</SPAN> <SPAN
style="COLOR: rgb(255,153,0)">/* Pointer to
first quantum set
*/</SPAN><BR> <SPAN
style="COLOR: rgb(0,0,255)">int</SPAN>
?? 快捷鍵說(shuō)明
復(fù)制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號(hào)
Ctrl + =
減小字號(hào)
Ctrl + -