2015-10-26 26 views
0

我實現了從Linux中前項目獲取用於嵌入式系統,我需要做的是非常簡單的一個framebuffer司機:繪製一個小矩形,其中屏幕被觸摸。Linux的幀緩衝驅動和自定義文件操作

爲了做到這一點,我想使用的功能xxxfb_fillrect(),你可以在下面的驅動程序代碼中找到(部分被省略):

#include <linux/module.h> 
#include <linux/kernel.h> 
#include <linux/errno.h> 
#include <linux/string.h> 
#include <linux/mm.h> 
#include <linux/slab.h> 
#include <linux/delay.h> 
#include <linux/fb.h> 
#include <linux/init.h> 
#include <linux/pci.h> 
#include <linux/uaccess.h> 
#include <linux/vmalloc.h> 
#include <linux/console.h> 

#define PCI_VENDOR_ID_XXX 0x10F610F6 
#define PCI_DEVICE_ID_XXX 0x2864C826 
#define PCI_CLASS_MASK  0x00FF 

#define FB_NAME    "MFCC8556_vfb_" 
#define FB_MAJOR   29 
#define VIDEOMEMSIZE  (480*800*3) 

#define FBIO_TEST   _IO('F', 0x21) 

/* Global variable */ 

/* 
* Driver data 
*/ 
//static char *videomemory; 
static int fb_count = 3; 
static u_long videomemorysize = VIDEOMEMSIZE; 

/* array of framebuffer */ 
static struct fb_info **g_fb_list; 

static struct fb_fix_screeninfo fix_default __initdata = { 
    .id   = FB_NAME, 
    .smem_len = VIDEOMEMSIZE, 
    .type  = FB_TYPE_PACKED_PIXELS, 
    .visual  = FB_VISUAL_PSEUDOCOLOR, 
    .xpanstep = 0, 
    .ypanstep = 0, 
    .ywrapstep = 0, 
    .accel  = FB_ACCEL_NONE, 
}; 


static struct fb_var_screeninfo var_default __initdata = { 
    .xres   = 800, 
    .yres   = 480, 
    .xres_virtual = 800, 
    .yres_virtual = 480, 
    .bits_per_pixel = 24, 
    .red   = {0, 8, 0}, 
    .green   = {0, 8, 0}, 
    .blue   = {0, 8, 0}, 
    .grayscale  = 0, 
    .activate  = FB_ACTIVATE_TEST, 
    .height   = -1, 
    .width   = -1, 
    .pixclock  = 30060, 
    .vmode   = FB_VMODE_NONINTERLACED, 
}; 

static int xxxfb_init(void); 
static int register_fb(struct fb_info *info); 
static int set_screen_base(struct fb_info* info); 
static int init_fb_info(struct fb_info *info, struct fb_ops *fbops, unsigned int id_no); 
static int alloc_fb_info (struct fb_info **info); 


/* ------------ Accelerated Functions --------------------- */ 

/* 
* We provide our own functions if we have hardware acceleration 
* or non packed pixel format layouts. If we have no hardware 
* acceleration, we can use a generic unaccelerated function. If using 
* a pack pixel format just use the functions in cfb_*.c. Each file 
* has one of the three different accel functions we support. 
*/ 

/** 
*  xxxfb_fillrect - REQUIRED function. Can use generic routines if 
*   non acclerated hardware and packed pixel based. 
*   Draws a rectangle on the screen.  
* 
*  @info: frame buffer structure that represents a single frame buffer 
* @region: The structure representing the rectangular region we 
*  wish to draw to. 
* 
* This drawing operation places/removes a retangle on the screen 
* depending on the rastering operation with the value of color which 
* is in the current color depth format. 
*/ 
void xxxfb_fillrect(struct fb_info *info, const struct fb_fillrect *region) 
{ 
/* Meaning of struct fb_fillrect 
* 
* @dx: The x and y coordinates of the upper left hand corner of the 
* @dy: area we want to draw to. 
* @width: How wide the rectangle is we want to draw. 
* @height: How tall the rectangle is we want to draw. 
* @color: The color to fill in the rectangle with. 
* @rop: The raster operation. We can draw the rectangle with a COPY 
*  of XOR which provides erasing effect. 
*/ 

    struct fb_fillrect *tmp_fillrect; 

    /*ptr=(unsigned long*)info->screen_base; 
    //fill the screen base /// 
    for(i=0; i<800*10; i++){ 
     *ptr=0x0000FF00; 
     ptr++; 
    }*/ 

    printk(KERN_DEBUG "\nfb_fillrect()"); 
    printk(KERN_DEBUG "\nFix Screen Info.id =%s\n", info->fix.id); 
/* printk(KERN_INFO "\nstruct fb_fillrect:\n" 
         "dx = %d\n" 
         "dy = %d\n" 
         "width = %d\n" 
         "height = %d\n" 
         "color = 0x%08X\n" 
         "rop = 0x%X\n___\n" 
         , region->dx, region->dy, region->width, region->height, region->color, region->rop); 
         */ 
// printk(KERN_INFO "_in fill_rectangle : screen_base = 0x%X\n0x_%02X_%02X_%02X_%02X\n...\n",(unsigned int)info->screen_base, *info->screen_base, *(info->screen_base+1), *(info->screen_base+2),*(info->screen_base+3)); 


    tmp_fillrect = kmalloc(sizeof(struct fb_fillrect), GFP_KERNEL); 
    *tmp_fillrect = *region; 

/*tmp_fillrect->dx=400; 
    tmp_fillrect->dy=200; 
    tmp_fillrect->width=100; 
    tmp_fillrect->height=50; 
    tmp_fillrect->color=0x0000FF00; 
    tmp_fillrect->rop=0x0; 

*/ 
//tmp = copy_from_user(tmp_fillrect, region, sizeof(struct fb_fillrect)); 

    printk(KERN_INFO "\nstruct fb_fillrect:\n" 
         "dx = %d\n" 
         "dy = %d\n" 
         "width = %d\n" 
         "height = %d\n" 
         "color = 0x%08X\n" 
         "rop = 0x%X\n___\n" 
         , tmp_fillrect->dx, tmp_fillrect->dy, tmp_fillrect->width, tmp_fillrect->height, tmp_fillrect->color, tmp_fillrect->rop); 

    //if (tmp) printk(KERN_ERR "**ERROR: copy_from_user = %d\n", tmp); 

    cfb_fillrect(info, region); 

} 

... 

int xxxfb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg){ 

    int ret = 0; 

    printk(KERN_INFO "fb_ioctl()"); 
    mutex_lock(&info->lock); 

    switch(cmd) { 
    case FBIOGET_VSCREENINFO: 
     printk(KERN_DEBUG "FBIOGET_VSCREENINFO"); 
     break; 

    case FBIOGET_FSCREENINFO: 
     printk(KERN_DEBUG "FBIOGET_FSCREENINFO"); 
     break; 

    case FBIO_TEST: 
     printk(KERN_DEBUG "FBIO_TEST"); 
     break; 

    default: 
     printk(KERN_DEBUG "ioctl DEFAULT"); 
     break; 
    } 

    mutex_unlock(&info->lock); 

    return ret; 
} 


    /* 
    * Frame buffer operations 
    */ 

static struct fb_ops xxxfb_ops = { 
    .owner   = THIS_MODULE, 
    .fb_open  = xxxfb_open, 
    .fb_read  = fb_sys_read, 
    .fb_write  = fb_sys_write, 
    .fb_release  = xxxfb_release, 
    .fb_check_var = xxxfb_check_var, 
    .fb_set_par  = xxxfb_set_par, 
    //.fb_setcolreg = xxxfb_setcolreg, 
    .fb_blank  = xxxfb_blank, 
    .fb_pan_display = xxxfb_pan_display, 
    .fb_fillrect = xxxfb_fillrect, /* Needed !!! */ 
    .fb_copyarea = xxxfb_copyarea, /* Needed !!! */ 
    .fb_imageblit = xxxfb_imageblit, /* Needed !!! */ 
    .fb_cursor  = xxxfb_cursor,  /* Optional !!! */ 
    .fb_sync  = xxxfb_sync, 
    .fb_ioctl  = xxxfb_ioctl, 
    .fb_mmap  = xxxfb_mmap, 
}; 

/* ------------------------------------------------------------------------- */ 

... 

    /* 
    * Modularization 
    */ 

module_init(xxxfb_init); 
module_exit(xxxfb_exit); 

MODULE_LICENSE("GPL"); 

但事實是,我不知道如何稱它。我最終沒有使用這個fb_fillrect()手動實現矩形的繪製。

我知道這是不是一個平常open/rd/wr/ ...操作,但它是在這裏。我如何使用它?我應該撥打ioctl()嗎?如果是,爲什麼fb_fillrect出現在幀緩衝區操作結構中?

非常感謝您的幫助。

回答

0

fb_ops的功能是不直接暴露於用戶空間低級別的操作。取而代之的是,有一種結構fb_fopsdrivers/video/fbdev/core/fbmem.c包含該open/read/write/ioctl從用戶空間中的處理程序的功能(見下面的代碼)。這些處理函數中的一些可能會調用驅動程序中的fb_ops函數(請參閱do_fb_ioctl函數)。

static const struct file_operations fb_fops = { 
    .owner = THIS_MODULE, 
    .read =  fb_read, 
    .write = fb_write, 
    .unlocked_ioctl = fb_ioctl, 

    ... 

}; 

static long fb_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
{ 
    struct fb_info *info = file_fb_info(file); 

    if (!info) 
     return -ENODEV; 
    return do_fb_ioctl(info, cmd, arg); 
} 

static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, 
     unsigned long arg) 
{ 
    struct fb_ops *fb; 

    ... 

    switch (cmd) { 
    case FBIOGET_VSCREENINFO: 
     ... 
    case FBIOPUT_VSCREENINFO: 
     ... 
    case FBIOGET_FSCREENINFO: 
     ... 
    case FBIOPAN_DISPLAY: 
     ... 

    default: 
     if (!lock_fb_info(info)) 
      return -ENODEV; 
     fb = info->fbops; 
     if (fb->fb_ioctl) 
      ret = fb->fb_ioctl(info, cmd, arg); 
     else 
      ret = -ENOTTY; 
     unlock_fb_info(info); 
    } 
    return ret; 
} 

在其他情況下,fb_ops功能可以通過像fbcon上的fbdev頂部工作的驅動程序一起使用。以下是由幀緩衝控制檯驅動程序http://lxr.free-electrons.com/source/drivers/video/console/fbcon_cw.c#L80直接調用fb_fillrect的示例。

static void cw_clear(struct vc_data *vc, struct fb_info *info, int sy, 
        int sx, int height, int width) 
{ 
     struct fbcon_ops *ops = info->fbcon_par; 
     struct fb_fillrect region; 

     ... 

     info->fbops->fb_fillrect(info, &region); 
}