|
1、驱动源代码
$ \( X4 ~0 B8 k5 ?7 U! m
7 ^6 \' k- b, p0 b) i
' I0 ^9 w/ b$ b#include <linux/module.h>
2 |: ]- n/ c/ X: ?#include <linux/kernel.h>2 g! e1 G2 t8 x5 s* h- c' E
#include <linux/fs.h>
: p y" u; m9 L# k4 @#include <linux/init.h>
- H5 q$ Q) d! Z+ I#include <linux/device.h>4 J9 ~0 m& p" Y% x
#include <linux/miscdevice.h>
0 n! A5 F u% |7 o#include <linux/delay.h>
' K; P' x' m0 h* ?# c3 c" W! g#include <linux/mm.h>
4 b$ Z0 S# e* `* p3 m. A( D#include <asm/irq.h>2 C$ M) p+ @% J3 A
#include <asm/arch/regs-timer.h>: D2 l/ @- E p! I5 W4 I3 f
#include <asm/arch/regs-adc.h>
* Z% r& b4 g4 |#include <asm/arch/regs-gpio.h>
( a0 t: l7 B$ r6 a9 t#include <asm/arch/map.h>
- [1 h7 Z( S( T4 _6 h ]( m: a#include <asm/arch/regs-irq.h>+ ?7 Y3 k2 z6 `+ t
#include <asm/io.h>0 L" h; B) o4 X! N) g
#include <asm/hardware.h>
+ D. W0 u9 [8 J2 u#include <asm/uaccess.h>
1 d/ z3 T. r' r4 q* F8 C#include <asm/system.h>
+ t `# x2 p8 x! x& { P2 W#include <linux/errno.h>- P2 L( c/ {* d" B, w4 w2 ?
#include <linux/slab.h>* x/ |) P% L0 S
#include <linux/input.h>
5 @! A& p. u7 {1 h; j' q#include <linux/serio.h>+ n$ e/ X& R! R) L& L9 f
#include <linux/clk.h># R. ?6 X6 m7 k* u' _( @( u
#include <linux/cdev.h># a. i# R2 l& T1 ^" F
% R( J+ R9 [0 k7 j/ `% L% f9 `
) F5 ]9 p8 |0 d0 t7 d: T
8 e D4 i! F/ F: r1 I
+ H# r ^4 ?+ }1 d3 X6 w#define ADC_WRITE(ch, prescale) ((ch) << 16 | (prescale))0 j8 u! e+ M+ X. c r$ {0 v
6 j, ~+ k& v" m3 a$ s- N b+ d2 {8 B9 b
#define ADC_WRITE_GETCH(data) (((data) >> 16) & 0x7)
. v5 a* l6 H( q#define ADC_WRITE_GETPRE(data) ((data) & 0xff); K: L, K$ g1 _; j4 I! u4 ^
" z3 e6 w A. b, k' S) \1 n. R; p6 m/ c# v
#define DEVICE_NAME "adc"1 T% j& ~/ q2 `. U/ O% X2 J8 F
6 c/ F* Q( s% n/ _0 L7 E7 U. q T6 f0 Q
static void __iomem *base_addr;
/ \4 `* v' I c( ^: c- O' Z% D- z0 M, v5 D: F8 K; k H' w
0 E. K9 ?( ~. [5 V t' S
typedef struct { //adc转换的设备结构体
1 `5 U2 a3 o8 x wait_queue_head_t wait; //等待队列) Z# y0 Q! i2 B7 V0 n
int channel; //ADC转换通道8 i6 ^# M0 @6 k8 i) }2 D
int prescale;
% ?* ^9 n& n. h6 s}ADC_DEV;
* N7 {1 `: |0 X8 Q6 P( ?. W K: D$ D# M' M+ ]6 _6 p
; F3 i! L$ n+ `: L9 |7 {( N8 B2 {DECLARE_MUTEX(ADC_LOCK); //定义互斥信号量
9 Z5 C. B* M9 j1 u% ]' hstatic int ADC_OK = 0;8 c; F _6 `4 L# v' e) Q |
# t1 D9 Y O# a) c! \+ m& b9 E4 u
' _. i5 s7 @7 w; z' }
static ADC_DEV adcdev;
7 x7 g) v4 }2 Mstatic volatile int ev_adc = 0;. b1 ]. v% G6 C. |+ ?
static int adc_data;3 z9 ^! B/ I$ D2 Y8 J
$ ~8 T. q# m/ y7 f7 y1 g/ N% [1 \$ l$ @: G1 P9 q; r
static struct clk *adc_clock;
) t* u. F' a( _ L; x) |0 H" d7 y* ?9 X+ N9 m; \- {
4 l& H* L( J! }* [) ^#define ADCCON (*(volatile unsigned long *)(base_addr + S3C2410_ADCCON)) //ADC control8 t( D ~5 @7 |& A/ G
#define ADCTSC (*(volatile unsigned long *)(base_addr + S3C2410_ADCTSC)) //ADC touch screen control
# R4 p1 ~" {2 z& W- C! I#define ADCDLY (*(volatile unsigned long *)(base_addr + S3C2410_ADCDLY)) //ADC start or Interval Delay
. q& ]5 @( ^1 I& c1 x% O#define ADCDAT0 (*(volatile unsigned long *)(base_addr + S3C2410_ADCDAT0)) //ADC conversion data 0) a' W( b, f) ~) T6 j3 |
#define ADCDAT1 (*(volatile unsigned long *)(base_addr + S3C2410_ADCDAT1)) //ADC conversion data 1
7 W' A1 A2 `. S7 t#define ADCUPDN (*(volatile unsigned long *)(base_addr + 0x14)) //Stylus Up/Down interrupt status% k' I' R6 I" k( i
$ P4 o Y5 x1 `3 X1 a& ^) s3 T; z$ d
$ n5 r, A+ P( Z; m0 N#define PRESCALE_DIS (0 << 14)
- i# b/ u- y! O/ v#define PRESCALE_EN (1 << 14) //使能预分频/ \3 {- _% K/ t! A5 f8 L3 C0 w
#define PRSCVL(x) ((x) << 6)//设定的预分频值
% j+ H5 @: E" A! s& O+ r$ ^#define ADC_INPUT(x) ((x) << 3) //选择ADC转换通道
. s) l) s2 u% ~! g/ S! m2 H6 w5 C#define ADC_START (1 << 0) // 启动ADC转换
; S! A4 ~* b! B [& d#define ADC_ENDCVT (1 << 15)
5 d6 `" y- c: S$ E8 J) M+ g4 ]; f- P" O
" F( E! ^1 a& K6 y6 a/ }5 B
//AD转换中断处理函数
; k: }: J- y" hstatic irqreturn_t adcdone_int_handler(int irq, void *dev_id)2 Y' Q2 F) t9 S5 f/ m9 J& J
{undefined
$ }* m; w: R: i6 c3 t/ v! Z if (ADC_OK)
0 V. W6 n, t( X/ _3 z: ] {undefined
4 v5 O! [) a& r- g. \4 S% v* j# D adc_data = ADCDAT0 & 0x3ff; //提取AD转换后的数据
5 s& a; T; P! R" S2 L& J3 r+ C7 a% A8 H$ u
/ A% }) O; [' o5 h9 ]4 h( ` ev_adc = 1; //转换结束唤醒等待的进程
& Q3 P K1 t/ b0 }; s I wake_up_interruptible(&adcdev.wait);
8 d e3 K6 }- X$ G: O/ W" G+ K }
1 h' F& l0 q D7 W' [* y. F2 N, ^8 p
7 g' @( P% S" D. b" _' a) C return IRQ_HANDLED;7 y, J7 T! F1 Z" i; Q$ L
}9 f' }* _3 ^* @8 Y
0 i' G' X: D2 [
* l+ T/ f8 h, r( R$ B, B X
static ssize_t s3c2410_adc_read(struct file *filp, char *buffer, size_t count, loff_t *ppos)$ ~9 F. P8 A2 t$ h- f6 d
{undefined4 P" {0 \1 E" p* i7 s
char str[20];
1 ]. W9 r: g: L, n* F* b1 ~ int value;
8 r$ \- J. u8 S" e2 M" u1 { size_t len;
* I$ c+ @) \/ B2 X, l3 v3 m if (down_trylock(&ADC_LOCK) == 0) //获得信号量 :获得不到信号量不会阻塞6 @9 D2 [/ T1 h
{undefined( g; k( O. h' v. a% Q) I/ s; u
ADC_OK = 1;//启动AD转换0 I' n" S( z+ R/ I1 |1 Q3 T$ l+ n
ADCCON = PRESCALE_EN | PRSCVL(adcdev.prescale) | ADC_INPUT((adcdev.channel)) ;* W+ Y6 ^" Z: m' _- T" B/ K
//使能预分频 设置预分频值 选择ADC转换通道5 z3 k( ^2 m/ x2 D3 h
ADCCON |= ADC_START; //启动AD转换
4 b, v* \1 W5 \ 8 E/ s7 F; t- P
wait_event_interruptible(adcdev.wait, ev_adc); //阻塞等待AD转换" W. t; T/ }- `7 v& L
( p, R1 H9 t- e+ \9 D. k/ Z
. i" N" j) V5 Z1 u6 {
ev_adc = 0;//清除转换标志位, @) U! k8 p7 \- Q( D& `2 R0 f" p
, s. C3 `; Y% A0 ?
7 f$ V) o4 C- P2 |0 A4 ]
// printk("AIN[%d] = 0x%04x, %d\n", adcdev.channel, adc_data, ADCCON & 0x80 ? 1:0);& e% j. ]& _; {6 F$ l. c
; I r9 t5 Q/ d7 b! r
' |- P% r3 {# \1 K/ ~
value = adc_data; //AD转换的数据
3 G" ~6 y7 c. ~$ X" [5 E sprintf(str,"%5d", adc_data);//数据转换0 a( A$ p5 H$ K2 D6 F& v& h& \
//copy_to_user(buffer, (char *)&adc_data, sizeof(adc_data));
* {: S$ U/ f' H+ ~* q
9 W+ U8 E- j5 ]* b! c7 v6 e. g% f- {- D% s4 V2 E( N
ADC_OK = 0;
, o8 a0 c* a m( s up(&ADC_LOCK);//释放信号量& N- F# M" d1 d
}
. W1 a$ `% k$ F3 |0 K6 U! @4 u else& F) S, x8 q& g/ h/ H @7 Z
{undefined+ u: v a1 i X+ J& a1 d3 S
value = -1;8 z N: ^; b% F6 r F8 t5 K# c
}
+ B* ^5 X# Z& r# W* c+ W. b, _5 D3 O) j: j
9 ]9 T: T0 q: _! i4 i- d
len = sprintf(str, "%d\n", value);
/ _5 G' w+ g7 C x if (count >= len)
. n$ E0 |/ S# y7 Y- V {undefined4 I7 M/ {$ _) b# g5 z
int r = copy_to_user(buffer, str, len); //把AD转换数据送回用户空间
& F7 W' ?: K* l9 \# Z+ f4 m2 n return r ? r : len;
; D! \4 q2 R) i3 U6 O }
/ a7 m/ c9 H# x$ Q else
' q, a2 z3 |0 [6 z4 ] {undefined* y; I4 t' b$ l l, E
return -EINVAL;2 n. o* d3 N, Q
}5 t1 i. p5 _9 l) n/ K, o8 t) s
}
" M" N0 u4 s2 k/ J& j4 j- m% B" A2 {! {! k
2 b1 x, p u& n8 \8 P
static int s3c2410_adc_open(struct inode *inode, struct file *filp)
; J! _/ F$ M' ^8 T( _{undefined8 N! ^$ x5 ]( E
init_waitqueue_head(&(adcdev.wait)); //初始化等待队列
9 L m" Q N) `: {9 Z e& A, [% {# e/ |9 u; o
6 q' V5 _/ L3 _5 y* M
adcdev.channel=0; //选择ADC转换的通道 //AIN 0 or (0~7)0 i( H5 W' r; }0 G# S: B
adcdev.prescale=0xff; //AD转换延时% e* L1 ^) d3 ?8 Z* | y
: t1 q0 K. b% T
# H. A3 N H5 x( T0 E+ I% u; N* B printk( "ADC opened\n");' ]/ _( F/ w( X- x, M# @
return 0;
! h0 l' f: c {, B2 e2 L1 {! c. g}7 H* J+ R- B) o! F1 B$ I# f6 }
! S' N' P3 ?& T
$ H6 R/ v6 i% u- ~static int s3c2410_adc_release(struct inode *inode, struct file *filp)! ^: z1 l2 |3 b6 b* X7 I: }. p
{undefined/ E* u9 G' r$ k* y' C
printk( "EmbedSky-ADC closed\n");7 l5 L: Q0 g3 q* o7 I
return 0;' S7 G8 [" r# w) W6 W0 g
}
7 a( g: ]- u1 I/ L3 s4 L( B( h0 e4 q5 t
* K2 o- U# l! o' w* bstatic struct file_operations Adc_fops = {undefined
. R; K$ Y" z" N owner: THIS_MODULE,
, V3 J& W% s7 U+ E open: s3c2410_adc_open,
, `. L( n4 W! C! E read: s3c2410_adc_read, 2 {/ `3 Y% W3 E! X% c4 ~% C
release: s3c2410_adc_release,0 x* y3 O6 n D3 H5 l
};: m# L, x1 Y3 x/ j9 P( X* a8 _% |
1 x# l% ]: D+ e+ {" o. u& ?
8 \2 Z0 }" p, ^/ B! L: H# {static struct miscdevice misc = {undefined
5 D6 z l3 ~' |4 d: `- m .minor = MISC_DYNAMIC_MINOR,
! ]) @8 E$ }; ]# v5 X2 p .name = DEVICE_NAME,; T ?/ [: ]% z0 G& Q
.fops = &Adc_fops,6 C/ q5 X3 q% {& A! ~
};# ^( Y; f# ], q: ^2 V
; b0 P" B2 ^5 r* g: e1 I @8 Z2 l ]" Y) L
static char __initdata banner[] = "S3C2440 ADC\n";
7 [1 r! B8 N- L a% J3 r8 |" p; P
0 u' [4 t$ B4 {, u0 _' }; h# u0 z
* g3 F p0 y; a, i& P+ wstatic int __init Adc_init(void); U; d, w I8 l- n) _( e/ U, H7 |$ x
{undefined
2 \! D! l% W* }/ f4 e int ret;
$ p. X1 S2 }, Y t: E5 E printk(banner);8 R; m; J+ S* X; D+ k- W% D
8 S5 e" U3 q% r
. e; _ F1 Z9 H5 V% _! f base_addr=ioremap(S3C2410_PA_ADC,0x20);//映射把物理地址映射为虚拟地址' x0 t- e# ~. s0 x" Y/ ^* Q
if (base_addr == NULL) //返回值检测
5 \5 X. e$ {+ Y- ~ {undefined
+ X: @7 X/ c8 a- W9 p3 Y: Q printk(KERN_ERR "Failed to remap register block\n");
" w5 u/ [8 r2 p9 Z return -ENOMEM;; N9 H/ m+ b$ o
}
' W: C6 h6 M6 ?4 o; S0 \( G2 F: F8 c
9 D5 D) o3 r/ \
adc_clock = clk_get(NULL, "adc"); //获得ADC的时钟, J2 R' _' s7 G0 B* }/ E* U
if (!adc_clock)
6 v5 \2 h4 M. I! j% v1 B {undefined
: d6 Z. p, |9 X4 I+ N: p; Q printk(KERN_ERR "failed to get adc clock source\n");7 X* n$ w, L" r J% q% C7 \
return -ENOENT;# H2 L3 j" Y U+ p) `! \# d) }
}( {: K5 e+ b2 p, R" o! {6 w
clk_enable(adc_clock);//使能ADC的时钟/ a" |" c4 H5 O$ n) p
! ?* \( u* g" ]! o7 v6 U8 D6 f
/* normal ADC */- F9 K/ ?0 L1 B4 K
ADCTSC = 0;//不使用触摸屏2 c6 E$ S2 G! H
: T$ \4 q. d* h f9 J0 ?0 f8 \: F. B( }* ?/ ?' G$ o5 t
ret = request_irq(IRQ_ADC, adcdone_int_handler, IRQF_SHARED, DEVICE_NAME, &adcdev);//注册中断
/ l3 b. E: e( @: ? if (ret)8 T$ s; q! J u+ _- H2 K4 S5 \
{undefined
, h% i# ^' B# }: J2 d iounmap(base_addr);
9 o& Y' _* T( w. w return ret;
& ]: W1 D; @2 ]" }# L }, A) T! N, m: K! W8 e) o) |$ M$ _
+ v8 S+ N0 o2 f& {! k Y
! m8 J- r2 \/ K$ d0 R( M' a6 R
ret = misc_register(&misc);//注册一个混杂设备
4 P$ @& D3 V8 N& S( {/ b- a( b, h; G% \9 N0 M4 L: B& B! N% E) V
% ]$ P$ \. x1 C, U& v2 } printk(DEVICE_NAME " initialized\n");1 w6 |1 J6 X' \8 m) z
return ret;" v2 G8 T# `6 @
}
8 |. \8 Y; s+ G" p8 J, O0 L0 w
+ y+ U2 F0 m6 j& `3 S0 P) _7 d P3 G+ I: @: i& d4 E' L
static void __exit Adc_exit(void)7 l3 y( p# f/ K5 j1 n
{undefined
: P% T) |1 O4 P free_irq(IRQ_ADC, &adcdev);//注销中断
3 f. v: T$ `/ M/ E$ ` iounmap(base_addr); //解除映射
" {3 `9 T3 k8 }- |' ~
4 w# g0 ?% r/ v. P' H! K4 |/ @' O" C
if (adc_clock)( v9 ]& r# d* ?
{undefined5 ~1 h- x5 C: A" ^" B/ n( v
clk_disable(adc_clock);//关闭adc转换的时钟
* S2 S2 Y' B- |) N( ^* G clk_put(adc_clock);
4 Y( z2 u) U+ X3 h8 Q- P) M+ y1 A6 h adc_clock = NULL;
/ |3 R2 G9 U' p }- G5 N3 u- @1 z1 x' y7 \! j% U$ }2 B
8 Z% x- k8 W. o* i! z( I
) E& M! t" |9 j misc_deregister(&misc);//注销混杂设备, y0 X" \. g; G
}
. Y+ Z2 s# P; x! o8 c8 D5 b- u. o1 y* C( m0 e1 C7 \% t
( T1 E# }* P! f" y( l1 \EXPORT_SYMBOL(ADC_LOCK);' g- [) |, [- x4 s! g3 K, X
- `' M5 Q! ^* @/ s" W
9 f1 w1 ~6 e0 t- I! |: M; s
# P) \/ h, Q/ k" p
* y. g+ W. Y, Ymodule_init(Adc_init);
; H" O3 q2 J1 U, r/ y) Y$ {/ |module_exit(Adc_exit);# n: a* n. G+ E. a5 |% ^6 b9 l h. T9 u
. \1 p2 w- @- D9 C8 w8 H
; g6 j$ A7 P) G" D1 V2 E# F5 v
$ ^9 s" y" M0 L$ r ?$ U
S: W" G; ~" q! l3 p, T$ g& RMODULE_LICENSE("GPL"); & }4 _9 ~0 b1 O2 l6 H) ^
2、应用程序
1 I+ C8 ]6 ~1 V3 D, m3 H0 V, U/ ~5 R) S6 S0 x
0 n% X2 E, J) r' n" [, } @#include <stdio.h>
* F& F% G" H) ^: k% o+ ~+ _- ]#include <stdlib.h>& j$ J& E) P( f/ r/ g2 x
#include <unistd.h>
$ M% \6 T7 s( h r* x#include <sys/ioctl.h>! A% O8 o1 U! L
#include <sys/types.h> z% d& y/ @5 a) T$ ]
#include <sys/stat.h>
( X( Z" s! o/ y9 g" x' U; u#include <fcntl.h>$ v' u: n% f J* G. B0 y& E
#include <sys/select.h>7 A' _% `1 d% m: Y
#include <sys/time.h>- c" Z' b: s* [0 |, Z
#include <errno.h>
' m+ `1 f8 w$ O8 X* ?#include <linux/input.h>( t3 D/ v2 _+ B
int main(void)
* k8 a$ Z) [( V9 T+ f& C) ^{undefined6 W! c9 t4 `2 A
int adc_fd;; B. q9 N5 i$ L0 s: I- K" d
int count;, h: q/ h" U8 A$ K, z0 B% B
char adc[6];. [9 m+ q. l" F5 C& n
adc_fd = open("/dev/adc", O_RDWR); //以阻塞的方式打开设备文件
% z9 Z3 v$ W3 v/ Q3 `7 ^, p/ o if (adc_fd < 0) {undefined
" ^0 ?/ d' V5 K: u perror("open device adc_fd");. u4 `; X X8 a; L3 k3 d
exit(1);
- G$ O! M& z$ S! | }
- Z# ^) v9 m$ M% y$ u5 p- |, J8 X# [0 I' A
) ]9 A! _& M3 J L4 t4 k4 H4 x8 @ for (;;) {undefined# u. d. h. V1 m6 V) H/ ^ V
count = read(adc_fd,&adc,sizeof(adc));- z. @3 v( ~! U6 q ^% f8 r7 u
adc[count]='\0';
/ X1 w, C! [: w6 w printf(" adc = %s\n", adc);, X" Q5 @# B5 t: x
sleep(2);//2秒钟采样一次5 z% z2 L2 P( R/ x% U( [9 V
3 o, u( H6 h, x( P- o1 k
- U% K( W. z2 O- o: b9 g+ H }
6 @6 I, F) M* D4 ~% F y. d9 C2 P2 l$ U% R; S. |
8 E$ @0 a7 o6 I7 |" d2 ~ close(adc_fd);. O) K9 S) @- K1 j7 A
return 0;
" k# F) ?) H' H}& U: V1 _$ a0 |* \& `
希望能帮到你, {4 I$ G9 L' z* X+ y8 Q. }, Q
0 J4 ?- k0 s# t% | |
|