Linux-4.9.2内核在mini2440上的移植(九)——LCD驱动移植

本篇目的：添加背光驱动，添加LCD驱动。

本篇参考：

(1)背光添加：http://singleboy.blog.163.com/blog/static/54900194201152183748863/

(2)LCD驱动：http://singleboy.blog.163.com/blog/static/54900194201152113914540/

9.1 背光驱动添加

LCD的背光控制引脚是GPG4，这里我们先用0/1的方式开关LCD背光，以后再修改为PWM控制。

（1）进入到Linux源码文件夹，并在drivers/video/backlight/下建立一个背光驱动。

root@ubuntu:~#cd linux-4.9.2/

root@ubuntu:~/linux-4.9.2#vim drivers/video/backlight/mini2440_backlight.c

（2）添加驱动源码

#include <linux/errno.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/slab.h>#include <linux/input.h>#include <linux/init.h>#include <linux/serio.h>#include <linux/delay.h>#include <linux/clk.h>#include <linux/miscdevice.h>#include <linux/gpio.h> #include <asm/io.h>#include <asm/irq.h>#include <asm/uaccess.h>#include <mach/regs-clock.h>#include <mach/gpio-samsung.h>#include <mach/regs-gpio.h>#include <linux/cdev.h> #define DEVICE_NAME "backlight"#define DEVICE_MINOR 5 static long mini2440_backlight_ioctl(                structfile *file,               unsigned int cmd,               unsigned long arg){        switch(cmd)        {                case 0:                        gpio_set_value(S3C2410_GPG(4), 0);                        printk(DEVICE_NAME "turn off!\n");                       return 0;                case 1:                        gpio_set_value(S3C2410_GPG(4), 1);                       printk(DEVICE_NAME " turn on!\n");                        return 0;               default:                       return -EINVAL;        }}static struct file_operations dev_fops ={        .owner =THIS_MODULE,        .unlocked_ioctl= mini2440_backlight_ioctl,}; static struct miscdevice misc ={        .minor = DEVICE_MINOR,        .name =DEVICE_NAME,        .fops =&dev_fops,}; static int __init dev_init(void){        int ret;        ret =misc_register(&misc);        if(ret < 0)        {               printk("Register misc device fiald!");                returnret;        }       gpio_direction_output(S3C2410_GPG(4), 1);        return ret;} static void __exit dev_exit(void){       misc_deregister(&misc);} module_init(dev_init);module_exit(dev_exit); MODULE_LICENSE("GPL");MODULE_AUTHOR("ubuntu");MODULE_DESCRIPTION("Backlight control formini2440");

注意，linux4.9的GPIO驱动与linux2.6的GPIO驱动不同，

初始化并设置IO输出模式是：gpio_direction_output(S3C2410_GPG(4), 1);

IO电平状态设置是：gpio_set_value(S3C2410_GPG(4),0);

 

（3）添加make menu菜单

root@ubuntu:~/linux-4.9.2#vim drivers/video/backlight/Kconfig

 

定位到第11行，添加红色部分代码

#

# Backlight& LCD drivers configuration

#

 

menuconfigBACKLIGHT_LCD_SUPPORT

        bool "Backlight & LCD devicesupport"

        help

          Enable this to be able to choose thedrivers for controlling the

          backlight and the LCD panel on someplatforms, for example on PDAs.

 

config BACKLIGHT_MINI2440

 tristate"Backlight support for mini2440 from FriendlyARM"

 depends onBACKLIGHT_LCD_SUPPORT

 help

 backlight driver forMINI2440 from FriendlyARM

 

if BACKLIGHT_LCD_SUPPORT

 

#

# LCD

#

configLCD_CLASS_DEVICE

（4）修改makefile

root@ubuntu:~/linux-4.9.2#vim drivers/video/backlight/Makefile

 

在第24行，加入红色部分

obj-$(CONFIG_BACKLIGHT_88PM860X) += 88pm860x_bl.o
obj-$(CONFIG_BACKLIGHT_AAT2870) += aat2870_bl.o
obj-$(CONFIG_BACKLIGHT_ADP5520) += adp5520_bl.o
obj-$(CONFIG_BACKLIGHT_MINI2440) += mini2440_backlight.o
obj-$(CONFIG_BACKLIGHT_ADP8860) += adp8860_bl.o
obj-$(CONFIG_BACKLIGHT_ADP8870) += adp8870_bl.o

（5）在menuconfig中开启背光驱动。

root@ubuntu:~/linux-4.9.2#make menuconfig

在界面中找到

DeviceDrivers --->

Graphicssupport --->

 [*] Backlight & LCD device support  --->

就可以找到该配置选项，如图

选中后，保存退出。

 

9.2 添加LCD驱动

（1）修改mach-mini2440.c

root@ubuntu:~/linux-4.9.2# vim arch/arm/mach-s3c24xx/mach-mini2440.c

将从第112行

taticstruct s3c2410fb_display mini2440_lcd_cfg __initdata = {

开始，到154行

        .lpcsel         = ((0xCE6) & ~7) | 1<<4,

};

的代码全部删除

 

添加如下代码

#if defined(CONFIG_FB_S3C2410_N240320) #define LCD_WIDTH 240#define LCD_HEIGHT 320#define LCD_PIXCLOCK 100000 #define LCD_RIGHT_MARGIN 36#define LCD_LEFT_MARGIN 19#define LCD_HSYNC_LEN 5 #define LCD_UPPER_MARGIN 1#define LCD_LOWER_MARGIN 5#define LCD_VSYNC_LEN 1 #elif defined(CONFIG_FB_S3C2410_W320240)#define LCD_WIDTH 320#define LCD_HEIGHT 240#define LCD_PIXCLOCK 170000 #define LCD_RIGHT_MARGIN 0x44#define LCD_LEFT_MARGIN 0x04#define LCD_HSYNC_LEN 0x01 #define LCD_UPPER_MARGIN 10#define LCD_LOWER_MARGIN 4#define LCD_VSYNC_LEN 1 #define LCD_CON5 (S3C2410_LCDCON5_FRM565 |S3C2410_LCDCON5_INVVFRAME | S3C2410_LCDCON5_INVVLINE | S3C2410_LCDCON5_HWSWP ) #elif defined(CONFIG_FB_S3C2410_N480272)#define LCD_WIDTH 480#define LCD_HEIGHT 272#define LCD_PIXCLOCK 100000 #define LCD_RIGHT_MARGIN 36#define LCD_LEFT_MARGIN 19#define LCD_HSYNC_LEN 5 #define LCD_UPPER_MARGIN 1#define LCD_LOWER_MARGIN 5#define LCD_VSYNC_LEN 1 #elif defined(CONFIG_FB_S3C2410_TFT640480)#define LCD_WIDTH 640#define LCD_HEIGHT 480#define LCD_PIXCLOCK 40000 #define LCD_RIGHT_MARGIN 67#define LCD_LEFT_MARGIN 40#define LCD_HSYNC_LEN 31 #define LCD_UPPER_MARGIN 5#define LCD_LOWER_MARGIN 25#define LCD_VSYNC_LEN 1 #elif defined(CONFIG_FB_S3C2410_T240320)#define LCD_WIDTH 240#define LCD_HEIGHT 320#define LCD_PIXCLOCK 170000#define LCD_RIGHT_MARGIN 25#define LCD_LEFT_MARGIN 0#define LCD_HSYNC_LEN 4#define LCD_UPPER_MARGIN 1#define LCD_LOWER_MARGIN 4#define LCD_VSYNC_LEN 1#define LCD_CON5 (S3C2410_LCDCON5_FRM565 |S3C2410_LCDCON5_INVVDEN | S3C2410_LCDCON5_INVVFRAME | S3C2410_LCDCON5_INVVLINE| S3C2410_LCDCON5_INVVCLK | S3C2410_LCDCON5_HWSWP ) #elif defined(CONFIG_FB_S3C2410_X240320)#define LCD_WIDTH 240#define LCD_HEIGHT 320#define LCD_PIXCLOCK 170000#define LCD_RIGHT_MARGIN 25#define LCD_LEFT_MARGIN 0#define LCD_HSYNC_LEN 4#define LCD_UPPER_MARGIN 0#define LCD_LOWER_MARGIN 4#define LCD_VSYNC_LEN 9#define LCD_CON5 (S3C2410_LCDCON5_FRM565 |S3C2410_LCDCON5_INVVDEN | S3C2410_LCDCON5_INVVFRAME | S3C2410_LCDCON5_INVVLINE| S3C2410_LCDCON5_INVVCLK | S3C2410_LCDCON5_HWSWP ) #elif defined(CONFIG_FB_S3C2410_TFT800480)#define LCD_WIDTH 800#define LCD_HEIGHT 480#define LCD_PIXCLOCK 40000 #define LCD_RIGHT_MARGIN 67#define LCD_LEFT_MARGIN 40#define LCD_HSYNC_LEN 31 #define LCD_UPPER_MARGIN 25#define LCD_LOWER_MARGIN 5#define LCD_VSYNC_LEN 1 #elif defined(CONFIG_FB_S3C2410_VGA1024768)#define LCD_WIDTH 1024#define LCD_HEIGHT 768#define LCD_PIXCLOCK 80000 #define LCD_RIGHT_MARGIN 15#define LCD_LEFT_MARGIN 199#define LCD_HSYNC_LEN 15 #define LCD_UPPER_MARGIN 1#define LCD_LOWER_MARGIN 1#define LCD_VSYNC_LEN 1#define LCD_CON5 (S3C2410_LCDCON5_FRM565 |S3C2410_LCDCON5_HWSWP) #endif 

保存退出

 

（2）修改drivers/video/fbdev/Kconfig

root@ubuntu:~/linux-4.9.2# vim drivers/video/fbdev/Kconfig

 

在2073行附近加入红色部分代码

config FB_S3C2410_DEBUG
bool "S3C2410 lcddebug messages"
depends on FB_S3C2410
help
Turn on debuggingmessages. Note that you can set/unset at run time
through sysfs
choice
prompt "LCD select"
depends on FB_S3C2410
help
S3C24x0 LCD size select
config FB_S3C2410_W320240
boolean "3.5 inch 320X240 TFT Landscape LCD"
depends on FB_S3C2410
help
3.5 inch 320X240 TFT Landscape LCD
config FB_S3C2410_T240320
boolean "3.5 inch 240X320 Toppoly LCD"
depends on FB_S3C2410
help
3.5 inch 240X320 Toppoly LCD
config FB_S3C2410_X240320
boolean "3.5 inch 240X320 LCD(ACX502BMU)"
depends on FB_S3C2410
help
3.5 inch 240X320 LCD(ACX502BMU)
config FB_S3C2410_N240320
boolean "3.5 inch 240X320 NEC LCD"
depends on FB_S3C2410
help
3.5 inch 240x320 NEC LCD
config FB_S3C2410_N480272
boolean "4.3 inch 480X272 NEC LCD"
depends on FB_S3C2410
help
config FB_S3C2410_TFT640480
boolean "8 inch 640X480 L80 LCD"
depends on FB_S3C2410
help
8inch 640X480 LCD
config FB_S3C2410_TFT800480
boolean "7 inch 800x480 TFT LCD"
depends on FB_S3C2410
help
7inch 800x480 TFT LCD
config FB_S3C2410_VGA1024768
boolean "VGA 1024x768"
depends on FB_S3C2410
help
VGA 1024x768
endchoice
config FB_NUC900
tristate "NUC900LCD framebuffer support"
depends on FB&& ARCH_W90X900
select FB_CFB_FILLRECT
select FB_CFB_COPYAREA
selectFB_CFB_IMAGEBLIT
---help---
Frame buffer driverfor the built-in LCD controller in the Nuvoton
NUC900 processor

保存退出

 

（3）配置

root@ubuntu:~/linux-4.9.2# make menuconfig

现在，我们在命令行输入:makemenuconfig 进入内核配置，依次按下面的子菜单项选择：

 

Device Drivers --->

Graphics support --->

Frame buffer devices --->

        <*> Support forframe buffer devices --->  //这行选中，不用进入

            LCD select (3.5inch 240X320 Toppoly LCD) ---> //进入

                (X) 3.5 inch 240X320 LCD(ACX502BMU)    //根据自己开发板的屏幕型号选择，我的是X35

 

按空格或者回车键选择我们需要的 LCD 型号，然后退出保存内核配置。

 

9.3 编译测试

root@ubuntu:~/linux-4.9.2#make -j8

root@ubuntu:~/linux-4.9.2#./mkuImage.sh

 

重新启动开发板，可以看到屏幕上出现了小企鹅，并且下面打印了启动信息。