Linux-2.6.39在Tiny6410上的移植 - 外设驱动移植

Linux内核版本号：linux 2.6.39

交叉编译工具：arm-linux-gcc 4.5.1

Linux内核下载： www.kernel.org

开发板：友善之臂Tiny6410

LCD：友善之臂S70

一、移植LED驱动

打开arch/arm/mach-s3c64xx/mach-mini6410.c添加下列代码：

  1 static struct gpio_led tiny6410_gpio_led[] = {  2     [0] = {  3         .name = "led1",              //设备名  4         .gpio = S3C64XX_GPK(4),      //GPK4    5         .active_low = 1,             //低电平点亮  6         .default_state = LEDS_GPIO_DEFSTATE_ON,        //系统启动后默认为打开  7     },  8     [1] = {  9         .name = "led2", 10         .gpio = S3C64XX_GPK(5), 11         .active_low = 1, 12         .default_state = LEDS_GPIO_DEFSTATE_OFF,       //系统启动后默认关闭 13     }, 14     [2] = { 15         .name = "led3", 16         .gpio = S3C64XX_GPK(6), 17         .active_low = 1, 18         .default_state = LEDS_GPIO_DEFSTATE_ON, 19     }, 20     [3] = { 21         .name = "led4", 22         .gpio = S3C64XX_GPK(7), 23         .active_low = 1, 24         .default_state = LEDS_GPIO_DEFSTATE_OFF, 25     }, 26 }; 27  28 static struct gpio_led_platform_data tiny6410_leds_data = { 29     .num_leds = ARRAY_SIZE(tiny6410_gpio_led), 30     .leds = &tiny6410_gpio_led, 31 }; 32  33 static struct platform_device tiny6410_device_leds = { 34     .name = "leds-gpio", 35     .id = -1, 36     .dev = { 37         .platform_data = &tiny6410_leds_data, 38     }, 39 }; 

在mini6410_devices中添加tiny6410_device_leds，系统启动时将自动注册LED平台设备：

 1 static struct platform_device *mini6410_devices[] __initdata = { 2     ... 3     &tiny6410_device_leds, 4 }; 

执行make menuconfig修改内核配置，添加对LED设备的支持：

Device Drivers  --->

│ │    [*] LED Support  --->

编译并烧写内核，启动开发板可以看到第一、第三个LED被点亮。

编写应用程序控制LED：

系统LED设备名为每个LED设备创建了一个节点文件夹，位于/sys/devices/platform/leds-gpio/leds/目录下，对设备文件夹里面的brightness 文件写0或写非0即可对LED进行操作。

  1 #include <stdio.h>  2 #include <sys/stat.h>  3 #include <sys/types.h>  4 #include <fcntl.h>  5 #include <stdlib.h>  6 #include <string.h>  7   8   9 int main(int argc,char** argv) 10 { 11     int fd = 0; 12     char path[64] = "/sys/devices/platform/leds-gpio/leds/"; 13      14     if(argc != 3) 15     { 16         printf("format error!/n"); 17         return -1; 18     } 19      20     strcat(path,argv[1]); 21     strcat(path,"/brightness"); 22      23     printf("%s/n",path); 24     fd = open(path,O_RDWR); 25     if(fd == -1) 26     { 27         printf("open file failure!/n"); 28         return -1; 29     } 30     if(atoi(argv[2])) 31         write(fd,"1",1); 32     else 33         write(fd,"0",1); 34      35     close(fd); 36     return 0; 37 } 

二、按键驱动移植

在arch/arm/mach-s3c64xx/mach-mini6410.c添加下列代码：

  1 static struct gpio_keys_button tiny6410_gpio_keys[] = {  2     [0] = {  3         .code            = KEY_F1,        //键值  4         .type            = EV_KEY,        //按键输入类型  5         .gpio            = S3C64XX_GPN(0),  6         .active_low        = 1,           //低电平表示按下  7         .wakeup            = 0,  8         .debounce_interval    = 5, /* ms */    //延时消抖  9         .desc            = "Button 1", 10     }, 11     [1] = { 12         .code            = KEY_F2, 13         .type            = EV_KEY, 14         .gpio            = S3C64XX_GPN(1), 15         .active_low        = 1, 16         .wakeup            = 0, 17         .debounce_interval    = 5, /* ms */ 18         .desc            = "Button 2", 19     }, 20     [2] = { 21         .code            = KEY_F3, 22         .type            = EV_KEY, 23         .gpio            = S3C64XX_GPN(2), 24         .active_low        = 1, 25         .wakeup            = 0, 26         .debounce_interval    = 5, /* ms */ 27         .desc            = "Button 3", 28     }, 29     [3] = { 30         .code            = KEY_F4, 31         .type            = EV_KEY, 32         .gpio            = S3C64XX_GPN(3), 33         .active_low        = 1, 34         .wakeup            = 0, 35         .debounce_interval    = 5, /* ms */ 36         .desc            = "Button 4", 37     }, 38      39 }; 40  41 static struct gpio_keys_platform_data tiny6410_key_data = { 42     .buttons = &tiny6410_gpio_keys, 43     .nbuttons = ARRAY_SIZE(tiny6410_gpio_keys), 44 }; 45  46 static struct platform_device tiny6410_device_keys = { 47     .name = "gpio-keys", 48     .id = -1, 49     .dev = { 50         .platform_data = &tiny6410_key_data, 51     }, 52 }; 

在mini6410_devices中添加tiny6410_device_keys:

 1 static struct platform_device *mini6410_devices[] __initdata = { 2     .... 3     &tiny6410_device_leds, 4     &tiny6410_device_keys, 5 }; 

执行make menuconfig修改内核配置，添加对LED设备的支持：

Device Drivers  --->

│ │        Input device support  --->

Device Drivers  --->

│ │        Input device support  --->

│ │    <*>   Event interface

编译并烧写内核，启动开发板可以在/dev/目录下生成了event0设备文件，对按键驱动进行简单的测试：

执行hexdump /dev/event0

每次按下按键可以看到如下所示按键信息，表明按键是工作正常的。

 1 /dev # hexdump event0 2 0000000 034d 0000 0e3b 000c 0001 003b 0001 0000 3 0000010 034d 0000 0e4c 000c 0000 0000 0000 0000 4 0000020 034d 0000 cd5f 000e 0001 003b 0000 0000 5 0000030 034d 0000 cd6b 000e 0000 0000 0000 0000 

编写应用程序测试按键驱动：

按键驱动为输入子系统，应用程序中需要对event进行循环检测看系统有没有上报输入事件，按键的输入事件类型为EV_KEY，键值分别问KEY_F1、KEY_F2、KEY_F3、KEY_F4，数值为1表示按键按下为0表示按键释放。

  1 #include <stdio.h>  2 #include <sys/stat.h>  3 #include <sys/types.h>  4 #include <fcntl.h>  5 #include <stdlib.h>  6 #include <linux/input.h>  7   8 int main(void)  9 { 10     int fd = 0; 11     struct input_event event_key; 12     int count = 0; 13      14     fd = open("/dev/event0",O_RDONLY); 15     if(fd == -1) 16     { 17         printf("open file failed/n"); 18         return -1; 19     } 20      21     while(1) 22     { 23         count = read(fd,&event_key,sizeof(struct input_event)); 24         if(count < 0) 25         { 26             printf("read failed/n"); 27             break; 28         } 29         if(event_key.type == EV_KEY) 30         { 31             switch(event_key.code) 32             { 33                 case KEY_F1: 34                 { 35                     if(event_key.value == 1) 36                         printf("key1 pressed/n"); 37                     else if(event_key.value == 0) 38                         printf("key1 released/n"); 39                 } 40                 break; 41                 case KEY_F2: 42                 { 43                     if(event_key.value == 1) 44                         printf("key2 pressed/n"); 45                     else if(event_key.value == 0) 46                         printf("key2 released/n"); 47                 } 48                 break; 49                 case KEY_F3: 50                 { 51                     if(event_key.value == 1) 52                         printf("key3 pressed/n"); 53                     else if(event_key.value == 0) 54                         printf("key3 released/n"); 55                 } 56                 break; 57                 case KEY_F4: 58                 { 59                     if(event_key.value == 1) 60                         printf("key4 pressed/n"); 61                     else if(event_key.value == 0) 62                         printf("key4 released/n"); 63                 } 64                 break; 65             } 66         } 67          68     } 69      70     close(fd); 71     return 0; 72 } 

三、LCD显示屏移植

在arch/arm/mach-s3c64xx/mach-mini6410.c修改显示代码：

  1 static struct s3c_fb_pd_win mini6410_fb_win[] = {  2     {  3         .win_mode    = {    /* 7.0" 800x480 */  4             .left_margin    = 0x2c,//26,      5             .right_margin    = 0xd2,//210,     6             .upper_margin    = 0x15,//13,       7             .lower_margin    = 0x16,//22,      8             .hsync_len    = 0x02,//20,  9             .vsync_len    = 0x02,//10, 10             .xres        = 800, 11             .yres        = 480, 12         }, 13         .max_bpp    = 32, 14         .default_bpp    = 16, 15     },  16 }; 

参数的值根据LCD显示屏规格书确定，具体参数解释及计算见博客 http://blog.csdn.net/longxiaowu/article/details/24319933

执行make menuconfig修改内核配置，添加对LCD设备的支持：

Device Drivers  --->

│ │        Input device support  --->

│ │        Graphics support  --->

│ │    <*> Support for frame buffer devices  --->

│ │    <*>   Samsung S3C framebuffer support

│ │    [*] Bootup logo  --->               //开机显示小企鹅

编译烧写内核并开机，屏幕上并没有看到小企鹅。加载Tiny6410一线触摸设备驱动之后小企鹅出来了，应该是Tiny6410 S70屏幕的背光是在一线触摸中进行打开的，由于一线触摸的协议并不开源所以没有进行深究。

四、触摸屏校验程序tslib移植

见博客： http://www.cnblogs.com/ape-ming/p/5134542.html