Embedded System Software I

Transcription

1 Lee, Jae Heung

2 ?.. Application Area Application System Call Interface Virtual File System(VFS) Buffer Cache Network Subsystem Character Device Driver Block Device Driver Network Device Driver Device Interface Hardware Hardware 1

3 2

4 Kernel / User Address Space memcpy(), unsigned long copy_to_user(void *to, const void *from, unsigned long count) ; unsigned long copy_from_user(void *to, const void *from, unsigned long count) ; put_user(void *x, const void *a ddr) get_user(void *x, const void *a ddr) reentrant ( ) c o nc u rrent( ) semaphore spi n l oc k I / O -> ) L E D u n s i g n e d c h a r * a d d r ; a d d r = ( u n s i g n e d c h a r * ) ( 0 x f ) ; * a d d r = 0 x a 5 ; 3

5 -. - g et _ u ser( v oi d * x, c on st v oi d * ad d r) * a d d r x s i z eo f (a d d r ). ex) g et _ u s er ( c, g d a t a ); pu t _ u ser( v oi d * x, c on st v oi d * ad d r) * x u s er a d d r s i z eo f (a d d r ). ex) p u t _ u s er ( * a d d, ( u n s i g n ed s h o r t * ) ( g d a t a )); c opy _ t o_ u ser( v oi d * t o, v oi d * f rom, u n si g n ed l on g si z e) f r o m s i z e u s er t o. c opy _ f rom_ u ser( v oi d * t o, v oi d * f rom, u n si g n ed l on g si z e) u s er f r o m s i z e t o. 4

6 I / O u 8 i n b (u n s i g n ed i n t po r t ) u 1 6 i n w (u n s i g n ed i n t po r t ) u 3 2 i n l (u n s i g n ed i n t po r t ) I / O v o i d o u t b ( u 8 d a t a, u n s i g n ed i n t po r t ) v o i d o u t w ( u 1 6 d a t a, u n s i g n ed i n t po r t ) v o i d o u t l ( u 3 2 d a t a, u n s i g n ed i n t po r t ) 5

7 LED L E D M u s t u s e r e s i s t o r t o l i m i t c u r r e n t : D i s c r e t e L E D 8 Bit Write [ D0~D7 ] Ba s e A d d res s = 0x PXA255 Memory Controller MD(7:0) B U FF E R MA(22:20) Address Decoder CK CS4 6

8 LED LED M A P Discrete LED Control Register 7

9 LED LED I / O led (led. c) #include <linux/ioport.h> #include <asm/uaccess.h> #include <linux/module.h> #include <linux/fs.h> #include <asm/io.h> #define LEDIOPORT_MAJOR 0 // 0 #define LEDIOPORT_NAME "LED IO PORT" #define LEDIOPORT_MODULE_VERSION "LED IO PORT V0.1" #define LEDIOPORT_ADDRESS 0xf // LED #define LEDIOPORT_ADDRESS_RANGE 1 I/O port define static int ledioport_usage = 0; static int ledioport_major = 0; // LED int ledioport_open(struct inode *minode, struct file *mfile) { if(ledioport_usage!= 0) return -EBUSY; MOD_INC_USE_COUNT; ledioport_usage = 1; return 0; 8

10 LED (2) // LED int led_ioport_release(struct inode *minode, struct file *mfile) { MOD_DEC_USE_COUNT; ledioport_usage = 0; return 0; // LED ssize_t led_ioport_write_byte(struct file *inode, const char *gdata, size_t length, loff_t *off_what) { unsigned char *addr; unsigned char c; get_user(c, gdata); addr = (unsigned char *)(LEDIOPORT_ADDRESS); *addr = c; return length; // static struct file_operations led_fops = { write : ledioport_write_byte, open : ledioport_open, release : ledioport_release, ; LED write 9

11 LED (3) // int init_module(void) { int result; Character device result =register_chrdev(ledioport_major, LEDIOPORT_NAME, &led_fops); if(result < 0) { LEDIOPORT_MAJOR :, 0 printk(kern_warning"can't get any major\n"); return result; LEDIOPORT_N AME : /p r o c /d e v i c e s l e d _f o p s :. ledioport_major = result; if(!check_region(ledioport_address,ledioport_address_range)) request_region(ledioport_address,ledioport_address_range,ledioport_name); else printk(kern_warning"can't get IO Region 0x%x\n",LEDIOPORT_ADDRESS); printk("init module, ledioport major number : %d\n",result); return 0; c h e c k _r e g i o n ( 0xf , 1) / / 0xf ? r e q u e s t _r e g i o n ( 0xf , 1, L E D I O P O R T V 0. 1 ) / / 0xf ~ 0xf I / O L E D I O P O R T V 0. 1 check_region I / O -> req u es t _region I / O -> rel ea s e_region I / O -> 1 0

12 LED (4) // void cleanup_module(void) { release_region(ledioport_address,ledioport_address_range) if(unregister_chrdev(ledioport_major,ledioport_name)) printk(kern_warning"%s DRIVER CLEANUP FALLED\n",LEDIOPORT_NAME); Character device c h e c k _r e g i o n ( 0xf , 1) / / 0xf ? r e q u e s t _r e g i o n ( 0xf , 1, L E D I O P O R T V 0. 1 ) / / 0xf ~ 0xf I / O L E D I O P O R T V 0. 1 r e l e a s e _r e g i o n ( 0 x f , 1 ) / / check_region I / O -> req u es t _region I / O -> rel ea s e_region I / O -> 1 1

13 LED #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> // test.c int main(int argc, char **argv) { int dev; char buff; if(argc <= 1) { printf("please input the parameter! ex)./test 0xa1\n"); return -1; // dev = open("/dev/ledioport", O_WRONLY); LED Device file open 1 2

14 LED if (dev!= -1){ if(argv[1][0] == '0' && (argv[1][1] == 'x' argv[1][1] == 'X')) // buff = (unsigned char)strtol(&argv[1][2],null,16); else buff = atoi(argv[1]); // write(dev,&buff,1); close(dev); else{ printf( "Device Open ERROR!\n"); exit(-1); LED On/Off return(0); 1 3

15 M M Makefile C C = a r m -l i n u x-g c c / / K E R N E L D I R = l i n u x r m k 4 -p xa 2 I N C L U D E D I R = -I $ ( K E R N E L D I R )/ i n c l u d e -I. / # # C F L A G S = -D K E R N E L -D M O D U L E -W a l l -O 2 -I $ ( I N C L U D E D I R ) O D U L E _ O B J S = l e d i o p o r t. o O D U L E _ S R C S = l e d i o p o r t. c # #,, T E S T _ T A R G E T = t e s t T E S T _ O B J S = t e s t. o T E S T _ S R C S = t e s t. c # # m a k e a l l a l l : $ ( M O D U L E _ O B J S ) $ ( T E S T _ T A R G E T ) # # $ ( M O D U L E _ O B J S ) : $ ( C C ) $ ( C F L A G S ) -c $ ( M O D U L E _ S R C S ) # # $ ( T E S T _ T A R G E T ) : $ ( T E S T _ O B J S ) $ ( C C ) $ ( T E S T _ O B J S ) -o # # m a k e c l e a n c l e a n : r m -f *. o r m -f $ ( T E S T _ T A R G E T ) 1 4

16 LED LED $ make LED led iop ort. o led _ test insm od loa d ing m k nod $ insmod ledioport.o Using ledioport.o Init module, ledioport major number : 253 $ mknod /dev/ledioport c $./test 0xff 1 5

17 7-segment display M a y u s e p a r a l l e l o r m u l t i p l e x e d i n p u t a f e g d b c 1 6

18 7 Segment 7 S e g m e n t LED 1 7

19 7 Segment 4 D i g i t 7 s e g m e n t Physical Address : 0x1030_ Segment LED Data Register Bit D1H D1G D1F D1E D1D D1C D1B D1A D2H D2G D2F D2E D2D D2C D2B D2A Reset x x x x x x x x x x x x x x x x Bits Name Description 7:0 D2H:D2A Digit 1 Segment Bit [ 0-A, 1-B, 2-C, 3-D, 4-E, 5-F, 6-G, 7-H ] 15:8 D1H:D1A Digit 2 Segment Bit [ 8-A, 9-B, 10-C, 11-D, 12-E, 13-F, 14-G, 15-H ] Physical Address : 0x1040_0000 Bit D4H D4G D4F D4E D4D D4C D4B D4A D3H D3G D3F D3E D3D D3C D3B D3A Reset x x x x x x x x x x x x x x x x Bits Name Description 7:0 15:8 D4A:D4H 7 Segment LED Data Register D3A:D3H Digit 3 Segment Bit [ 0-A, 1-B, 2-C, 3-D, 4-E, 5-F, 6-G, 7-H ] Digit 4 Segment Bit [ 8-A, 9-B, 10-C, 11-D, 12-E, 13-F, 14-G, 15-H ] 18

20 7 Segment (1) (segmentport.c) #include <linux/module.h>.. #include <linux/ioport.h> #define SEGMENTPORT_MAJOR 0 // 0 #define SEGMENTPORT_NAME "SEGMENT PORT" #define SEGMENTPORT_MODULE_VERSION "SEGMENT PORT V0.1" // #define SEGMENTPORT_ADDRESS_LOW 0xf // #define SEGMENTPORT_ADDRESS_HIGH 0xf #define SEGMENTPORT_ADDRESS_RANGE 4 I/O port define #define SEGMENTPORT_BASE 0xbb #define SEGMENT_WRITE_LOW _IOW(SEGMENTPORT_BASE,0,4) #define SEGMENT_WRITE_HIGH _IOW(SEGMENTPORT_BASE,1,4) unsigned int *addr_low; unsigned int *addr_high; //Global variable static int segmentport_usage = 0; static int segmentport_major = 0; 19

21 7 Segment (2) // 7 int segmentport_open(struct inode *minode, struct file *mfile) { if(segmentport_usage!= 0) return -EBUSY; MOD_INC_USE_COUNT; segmentport_usage = 1; addr_low = (unsigned int *)(SEGMENTPORT_ADDRESS_LOW); addr_high = (unsigned int *)(SEGMENTPORT_ADDRESS_HIGH); return 0; // 7 int segmentport_release(struct inode *minode, struct file *mfile) { MOD_DEC_USE_COUNT; segmentport_usage = 0; return 0; 2 0

22 7 Segment (3) // unsigned int Getsegcode(int x) { unsigned int code; switch (x) { case 0x0 : code = 0x3f; break; case 0x1 : code = 0x06; break; case 0x2 : code = 0x5b; break; case 0x3 : code = 0x4f; break; case 0x4 : code = 0x66; break; case 0x5 : code = 0x6d; break; case 0x6 : code = 0x7d; break; case 0x7 : code = 0x07; break; case 0x8 : code = 0x7f; break; case 0x9 : code = 0x6f; break; case 0xA : code = 0x77; break; case 0xB : code = 0x7c; break; case 0xC : code = 0x39; break; case 0xD : code = 0x5e; break; case 0xE : code = 0x79; break; case 0xF : code = 0x71; break; default : code = 0; break; return code; 7-segment code 2 1

23 7 Segment (4) // struct file_operations segment_fops = { write: segmentport_write, ioctl: segmentport_ioctl, open: segmentport_open, release: segmentport_release, ; // void cleanup_module(void) { release_region(segmentport_address_low,segmentport_address_ra NGE); release_region(segmentport_address_high,segmentport_address_ra NGE); if(!unregister_chrdev(segmentport_major,segmentport_name)) printk("driver : %s DRIVER CLEANUP Ok\n",SEGMENTPORT_NAME); else printk("driver : %s DRIVER CLEANUP FALLED\n",SEGMENTPORT_NAME); check_region I / O -> req u es t _region I / O -> rel ea s e_region I / O -> 2 2

24 7 Segment (5) // 7 void ShowSegment(unsigned short value) { unsigned int v0,v1,v2,v3; v0 = Getsegcode(value & 0xF); v1 = Getsegcode((value >> 4) & 0xF); v2 = Getsegcode((value >> 8) & 0xF); v3 = Getsegcode((value >> 12) & 0xF); *addr_low = (v1 << 8) v0; *addr_high = (v3 << 8) v2; // 7 ssize_t segmentport_write(struct file *inode, const char *gdata, size_t length, loff_t *off_what) { unsigned short val; get_user(val,(unsigned short *)gdata); ShowSegment(val); return length; 2 3

25 7 Segment (6) // int segmentport_ioctl(struct inode *inode, struct file *file,unsigned int cmd,unsigned long gdata) { unsigned int val; unsigned int val_low,val_high; switch(cmd){ case SEGMENT_WRITE_LOW: get_user(val,(unsigned int *)gdata); val_low = val % 10; val_high = val / 10; val_low = Getsegcode(val_low); val_high = Getsegcode(val_high); *addr_low = (val_high << 8) val_low; break; case SEGMENT_WRITE_HIGH: get_user(val,(unsigned int *)gdata); val_low = val % 10; val_high = val / 10; cmd val_low = Getsegcode(val_low); val_high = Getsegcode(val_high); *addr_high = (val_high << 8) val_low; break; default: printk("driver : no such command!\n"); return -ENOTTY; return 0; 2 4

26 7 Segment (7) // int init_module(void) { int result; result = register_chrdev(segmentport_major,segmentport_name,&segment_fops); if(result < 0) { printk(kern_warning"can't get any major\n"); return result; segmentport_major = result; if(!check_region(segmentport_address_low,segmentport_address_range)!check_region(segmentport_address_high,segmentport_address_range)) { request_region(segmentport_address_low,segmentport_address_range,segmen TPORT_NAME); request_region(segmentport_address_high,segmentport_address_range,segmen TPORT_NAME); printk("init module, segmentport major number : %d\n",result); else printk("driver : unable to register this!\n"); return 0; check_region I / O -> req u es t _region I / O -> rel ea s e_region I / O -> 2 5

27 7 Segment int main() // counter. c { int dev; unsigned int low_counter, high_counter; char ch = 'y',command; // dev = open("/dev/segmentport", O_WRONLY); if(dev < 0) { printf("application : segment driver open fails!\n"); return -1; FND Device file open printf("\n 7Segment Counter\n\n"); printf(" \n"); printf(" r for start the counter\n"); printf(" s for stop the counter\n"); printf(" c for continue the counter\n"); printf(" q for exit\n"); printf(" \n"); 2 6

28 7 Segment high_counter = low_counter = 0; init_keyboard(); command = 'r'; // 7 file_operation 20 ioctl(dev,segment_write_low,&low_counter,4); ioctl(dev,segment_write_high,&high_counter,4); ioctl // 'q' while(ch!= 'q') { // 's' 7 if(command!= 's') { ioctl(dev,segment_write_low,&low_counter,4); ioctl(dev,segment_write_high,&high_counter,4); low_counter++; // 99 0 if(low_counter>99) { low_counter = 0; high_counter++; if(high_counter > 59) high_counter = 0; 2 7

29 7 Segment // Delay usleep(10000); if(kbhit()){ ch = readch(); switch(ch){ case 'r': low_counter = 0; high_counter = 0; command = 'r'; break; case 'c': command = 'r'; break; case 's': command = 's'; break; high_counter = low_counter = 0x0000; write(dev,&low_counter,sizeof(unsigned short)); // close_keyboard(); close(dev); return 0; 2 8

30 7 Segment // void init_keyboard() { tcgetattr(0,&initial_settings); new_settings = initial_settings; new_settings.c_lflag &= ~ICANON; new_settings.c_lflag &= ~ECHO; new_settings.c_lflag &= ~ISIG; new_settings.c_cc[vmin] = 1; new_settings.c_cc[vtime] = 0; tcsetattr(0,tcsanow,&new_settings); // void close_keyboard() { tcsetattr(0,tcsanow,&initial_settings); 2 9

31 7 Segment // int kbhit() { char ch; int nread; if(peek_character!= -1) return 1; new_settings.c_cc[vmin] = 0; tcsetattr(0,tcsanow,&new_settings); nread = read(0,&ch,1); new_settings.c_cc[vmin] = 1; tcsetattr(0,tcsanow,&new_settings); if(nread == 1) { peek_character = ch; return 1; return 0; // int readch() { char ch; if(peek_character!= -1) { ch = peek_character; peek_character = -1; return ch; read(0,&ch,1); return ch; 3 0

32 M M 7 Segment Makefile CC = arm-l i n u x -g c c / / K E R N E L D I R = / h o me / e mb e d d e d 4 / l i n u x rmk 4 -p x a2 I N CL U D E D I R = -I $ ( K E R N E L D I R ) / i n c l u d e -I. / # # CF L A G S = -D K E R N E L -D M O D U L E -W al l -O 2 -I $ ( I N CL U D E D I R ) O D U L E _ O B J S = s e g me n t p o rt. o O D U L E _ S R CS = s e g me n t p o rt. c # #,, T E S T _ T A R G E T = c o u n t e r T E S T _ O B J S = c o u n t e r. o T E S T _ S R CS = c o u n t e r. c # # mak e al l al l : $ ( M O D U L E _ O B J S ) $ ( T E S T _ T A R G E T ) # # $ ( M O D U L E _ O B J S ) : $ ( CC) $ ( CF L A G S ) -c $ ( M O D U L E _ S R CS ) # # $ ( T E S T _ T A R G E T ) : $ ( T E S T _ O B J S ) $ ( CC) $ ( T E S T _ O B J S ) -o # # mak e c l e an c l e an : rm -f *. o rm -f $ ( T E S T _ T A R G E T ) 3 1

33 7 Segment F N D $ make F N D fnd.o fnd_ t e s t i ns m od l oa di ng m k nod $ insmod segmentport.o Using segmentport.o Init module, segmentport major number : 253 $ mknod /dev/segmentport c $./counter 3 2

34 Text LCD T ex t L C D 2 0 C h a r a c t e r s x 2 L i ne s / B a c k l i g h t T y p e 3 3

35 Text LCD Text LCD 3 4

36 TEXT LCD 2 Instruction R e g iste r( IR ) D a ta R e g iste r( D R ). X sca l e Text LCD 1 1 ( D0 ~ D7, R S, R / W, E ) 2 ( R S, R / W ) ( D0 ~ D7 ), E n a b l e o n / o f f X s c a l e Text LCD D0~D7 : D8 : R S D9 : R / W D1 0 : E Instruction Register(IR) Data Register(DR) Text LCD Text LCD 35

37 LCD LCD RS R/W D7 D6 D5 D4 D3 D2 D1 D0 Executed Time Clear Display mS Return Home uS Entry Mode Set I/D S 40uS Display on/off Control D C S 40uS Cursor or Display Shift S/C R/L uS Function Set D/L N F uS Set CG RAM Address CG RAM Address 40uS Set DD RAM Address DD RAM Address 40uS Read Busy Flag and Address 0 1 BF Address Counter 40uS Data Write to CG RAM or DD RAM 1 0 Write Address 40uS Data Read to CG RAM or DD RAM 1 1 Read Address 40uS RS: Register Select, R/W:Read Write, E:Enable 36

38 LCD LCD write RS(D8) R/W(D9) low E(D10) high low Text Lcd ex) // textlcdport.c void setcommand (unsigned short command) { command &= 0x00FF; outl ( (command 0x0000), TEXTLCD_ADD); outl ( (command 0x0400), TEXTLCD_ADD); outl ( (command 0x0000), TEXTLCD_ADD); udelay(50); 8 command OR 0X 0000, 0x 0400, 0x 0000 OR E low -> high -> low 37

39 LCD A d d r e s s Co u n t ( A C) AC D.D.R AM C.G.R AM Ad d r e s s Ad d r e s s I R, Ad d r e s s I R AC, D.D.R AM C.G.R AM. D D R AM x 00~ 0x 0F, 0x 4 0~ 0x 4 F 1, A 0B 0C 0D 0E 0F A 4B 4C 4D 4E 4F 38

40 LCD T e x t LCD Di s p l a y DA T A W r i t e DDRAM Address Set 1 B y te W ri te & Del a y 1 6 B y tes w ri te L i n e C h a n g e( f u n c ti o n set reg i ster) DDRAM Address Set 1 B y te W ri te & Del a y 1 6 B y tes w ri te 39

41 Text LCD (1) // void setcommand(unsigned short command){ command &= 0x00FF; outl((command 0x0000),TEXTLCDPORT_ADDRESS); outl((command 0x0400),TEXTLCDPORT_ADDRESS); outl((command & 0x0000),TEXTLCDPORT_ADDRESS); udelay(50); 8 command OR 0X 0000, 0x 0400, 0x 0000 OR // LCD void writebyte(char ch) { unsigned short data; data = ch & 0x00FF; E low -> high -> low outl((data 0x100),TEXTLCDPORT_ADDRESS); outl((data 0x500),TEXTLCDPORT_ADDRESS); outl((data 0x100),TEXTLCDPORT_ADDRESS); udelay(50); 4 0

42 Text LCD (2) // int clear_display(){ unsigned short command = 0x01; setcommand(command); udelay(2000); return 1; clear display (0x1) setcommand() Text LCD home( ) // int return_home(){ unsigned short command = 0x02; setcommand(command); udelay(2000); return 1; return home (0x02) setcommand() home 4 1

43 Text LCD (3) Entry Mode Set(0x04) increase nshift setcommand Text LCD // / int entry_mode_set(int increase, int nshift){ increase( [1], [0] ) unsigned short command = 0x04; nshift( [1], [0] ) command = increase? (command 0x2) : command; command = nshift? ( command 0x1) : command; setcommand(command); return 1; // On / Off,, int display_control(int display_enable, int cursor_enable, int nblink){ unsigned short command = 0x08; command = display_enable? (command 0x04) : command; command = cursor_enable? (command 0x02) : command; command = nblink? (command 0x01) : command; setcommand(command); Display on/off Control(0x08) display_enable cursor_enable, return 1; nbink [2],[1],[0] setcommand Text LCD display_enable( enable[1],disable[0]) cursor_enable( enable[1], disable[0]) nbink (on[1], off[0]) 4 2

44 Text LCD (4) // int cursor_shit(int set_screen, int set_rightshit){ unsigned short command = 0x10; command = set_screen? (command 0x08) : command; command = set_rightshit? (command 0x04) : command; setcommand(command); return 1; // LCD () int function_set(int rows, int nfonts){ unsigned short command = 0x30; Cursor or Display Shift(0x10) set_screen set_rightshit [3],[2] setcommand LCD set_screen ( set[1], clear[0]) set_rightshit( shift[1], [1]) if(rows == 2) command = 0x08; else if(rows == 1) command &= 0xf7; else return -1; command = nfonts? (command 0x04) : command; setcommand(command); return 1; function set (0x30) rows nfont [4],[3] setcommand TEXT LCD rows (2 [1], 1[0]) nfont (5x10 dot [1], 5 x 7 dot[0]) 4 3

45 Text LCD (5) //, LCD int set_ddram_address(int pos){ unsigned short command = 0x80; command += pos; setcommand(command); return 1; set DD RAM Address(0x80) pos command setcommand LCD pos 0x40 2 // LCD void initialize_textlcd(){ function_set(2,0); //Function Set:8bit,display 2lines,5x7 mod display_control(1,0,0); // Display on, Cursor off clear_display(); // Display clear entry_mode_set(1,0); // Entry Mode Set : shift right cursor return_home(); // go home LCD udelay(2000); 1. Function set( : 001x xx00) 2. Display ON/OFF Control(0000 1xxx) 3. Entry Mode Set( xx) 4. DD RAM 4 4

46 Text LCD (6) // LCD static int textlcdport_open(struct inode *minode, struct file *mfile) { if(textlcdport_usage!= 0) return -EBUSY; MOD_INC_USE_COUNT; textlcdport_usage = 1; MOD_INC_USE_COUNT initialize_textlcd(); return 0; INITIALIZE_TEXTLCD LCD // LCD static int textlcdport_release(struct inode *minode, struct file *mfile) { MOD_DEC_USE_COUNT; textlcdport_usage = 0; return 0;. open MOD_INC_USE_COUNT MOD_DEC_USE_COUNT 4 5

47 Text LCD (7) // LCD static ssize_t textlcdport_write(struct file *inode, const char *gdata, size_t length, loff_t *off_what) { struct strcommand_varible strcommand; copy_from_user(&strcommand,gdata,32); if(strcommand.rows == 0) write_string(0,strcommand.buf,strcommand.strlength); else if(strcommand.rows == 1) write_string(1,strcommand.buf,strcommand.strlength); return length; write gdata length gdata Text LCD length copy_from_user writebyte LCD 4 6

48 Text LCD (8) // ioctl, static int textlcdport_ioctl(struct inode *inode, struct file *file,unsigned int cmd,unsigned long gdata) { struct strcommand_varible strcommand; copy_from_user(&strcommand,(char *)gdata,32); switch(cmd){ case TEXTLCD_COMMAND_SET: setcommand(strcommand.command); break; case TEXTLCD_FUNCTION_SET: function_set((int)(strcommand.rows+1),(int)(strcommand.nfonts)); break; case TEXTLCD_DISPLAY_CONTROL: display_control((int)strcommand.display_enable, (int)strcommand.cursor_enable,(int)strcommand.nblink); break; case TEXTLCD_CURSOR_SHIFT: usrsor_shit((int)strcommand.set_screen,(int)strcommand.set_rightshit); break; case TEXTLCD_ENTRY_MODE_SET: entry_mode_set((int)strcommand.increase,(int)strcommand.nshift); break; case TEXTLCD_RETURN_HOME: return_home(); break; case TEXTLCD_CLEAR: clear_display(); break; case TEXTLCD_DD_ADDRESS: set_ddram_address((int)strcommand.pos); break; case TEXTLCD_WRITE_BYTE: writebyte(strcommand.buf[0]); break; default: printk("driver : no such command!\n"); return -ENOTTY; return 0; ioctl. gdata strcommand_variable. cmd. LCD 4 7

49 Text LCD (9) // static struct file_operations textlcd_fops = { write : textlcdport_write, ioctl : textlcdport_ioctl, open : textlcdport_open, release : textlcdport_release, ; file_operations // LCD void cleanup_module(void) { release_region(textlcdport_address,textlcdport_address_range); if(unregister_chrdev(textlcdport_major,textlcdport_name)) printk(kern_warning"%s DRIVER CLEANUP FALLED\n",TEXTLCDPORT_NAME); rmmod 4 8

50 Text LCD (10) register_chrdev // LCD request_region I/O int init_module(void){ int result; result = register_chrdev(textlcdport_major,textlcdport_name,&textlcd_fops); if(result < 0) { printk(kern_warning"can't get any major\n"); return result; insmod textlcdport_major = result; if(!check_region(textlcdport_address,textlcdport_address_range)) request_region(textlcdport_address,textlcdport_address_range,textlcdport_name); else printk(kern_warning"can't get IO Region 0x%x\n",TEXTLCDPORT_ADDRESS); printk("init module, textlcdport major number : %d\n",result); return 0; check_region I / O -> req u es t _region I / O -> rel ea s e_region I / O -> 49

51 LCD // test.c #define TEXTLCDPORT_BASE #define TEXTLCD_COMMAND_SET #define TEXTLCD_FUNCTION_SET #define TEXTLCD_DISPLAY_CONTROL #define TEXTLCD_CURSOR_SHIFT #define TEXTLCD_ENTRY_MODE_SET #define TEXTLCD_RETURN_HOME #define TEXTLCD_CLEAR #define TEXTLCD_DD_ADDRESS #define TEXTLCD_WRITE_BYTE struct strcommand_varible { char rows; char nfonts; char display_enable; char cursor_enable; char nblink; char set_screen; char set_rightshit; char increase; char nshift; char pos; char command; char strlength; char buf[20]; ; 0xbc _IOW(TEXTLCDPORT_BASE,0,32) _IOW(TEXTLCDPORT_BASE,1,32) _IOW(TEXTLCDPORT_BASE,2,32) _IOW(TEXTLCDPORT_BASE,3,32) _IOW(TEXTLCDPORT_BASE,4,32) _IOW(TEXTLCDPORT_BASE,5,32) _IOW(TEXTLCDPORT_BASE,6,32) _IOW(TEXTLCDPORT_BASE,7,32) _IOW(TEXTLCDPORT_BASE,8,32) Text LCD 5 0

52 LCD int main(int argc, char **argv) { int i,dev; // char buf[20] = "artoa lab"; char welcom[20] = "Welcome to"; char welcom2[20] = "the embeded World!"; struct strcommand_varible strcommand; // strcommand.rows = 0; strcommand.nfonts = 0; strcommand.display_enable = 1; strcommand.cursor_enable = 0; strcommand.nblink = 0; strcommand.set_screen = 0; strcommand.set_rightshit= 1; strcommand.increase = 1; strcommand.nshift = 0; strcommand.pos = 10; strcommand.command = 1; strcommand.strlength = 18; 5 1

53 LCD // buf memcpy(&strcommand.buf[0],buf,20); // dev = open("/dev/textlcdport", O_WRONLY O_NDELAY ); if (dev!= -1) { write(dev,&strcommand,32); sleep(2); ioctl(dev,textlcd_clear,&strcommand,32); strcommand.pos = 0; ioctl(dev,textlcd_dd_address,&strcommand,32); for(i=0;i<10;i++) { memcpy(&strcommand.buf[0],&wellcom[i],1); ioctl(dev,textlcd_write_byte,&strcommand,32); sleep(2); strcommand.pos = 40; ioctl(dev,textlcd_dd_address,&strcommand,32); for(i=0;i<18;i++) { memcpy(&strcommand.buf[0],&wellcom2[i],20); ioctl(dev,textlcd_write_byte,&strcommand,32); ioctl TEXTLCD_DD_ADDRESS ioctl TEXTLCD_WRITE_BYTE close(dev); else { printf( "application : Device Open ERROR!\n"); exit(-1); return(0); 5 2

54 Text LCD Makefile CC = arm-linux-gcc // KERNELDIR = /home/embedded4/linux rmk4-pxa2 INCLUDEDIR = -I$(KERNELDIR)/include -I./ ## CFLAGS = -D KERNEL -DMODULE -Wall -O2 -I$(INCLUDEDIR) MODULE_OBJS = textlcdport.o MODULE_SRCS = textlcdport.c ##,, TEST_TARGET = test TEST_OBJS = test.o TEST_SRCS = test.c ## make all all: $(MODULE_OBJS) $(TEST_TARGET) ## $(MODULE_OBJS) : $(CC) $(CFLAGS) -c $(MODULE_SRCS) ## $(TEST_TARGET) : $(TEST_OBJS) $(CC) $(TEST_OBJS) -o $@ ## make clean clean: rm -f *.o rm -f $(TEST_TARGET) 5 3

55 Text LCD LCD $ make LCD lcd.o lcd_ t e s t i n s m od loa di n g m k n od $ insmod textlcdport.o Using textlcdport.o Init module, textlcdport major number : 252 $ mknod /dev/textlcdport c $./test 5 4