git.ipfire.org Git - thirdparty/openwrt.git/blob

   1 From b27886692e427117c9dd270bbf6ea423761f293a Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Mon, 9 Oct 2023 16:32:45 +0100
   4 Subject: [PATCH 0678/1085] fbdev: Allow client to request a particular
   5  /dev/fbN node
   6
   7 Add a flag custom_fb_num to denote that the client has
   8 requested a specific fbdev node number via node.
   9
  10 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  11 ---
  12  drivers/video/fbdev/core/fbmem.c | 19 ++++++++++++++-----
  13  include/linux/fb.h               |  2 ++
  14  2 files changed, 16 insertions(+), 5 deletions(-)
  15
  16 --- a/drivers/video/fbdev/core/fbmem.c
  17 +++ b/drivers/video/fbdev/core/fbmem.c
  18 @@ -49,6 +49,7 @@ struct class *fb_class;
  19  DEFINE_MUTEX(registration_lock);
  20  struct fb_info *registered_fb[FB_MAX] __read_mostly;
  21  int num_registered_fb __read_mostly;
  22 +int min_dynamic_fb __read_mostly;
  23  #define for_each_registered_fb(i)              \
  24         for (i = 0; i < FB_MAX; i++)            \
  25                 if (!registered_fb[i]) {} else
  26 @@ -938,10 +939,12 @@ static int do_register_framebuffer(struc
  27                 return -ENXIO;
  28
  29         num_registered_fb++;
  30 -       for (i = 0 ; i < FB_MAX; i++)
  31 -               if (!registered_fb[i])
  32 -                       break;
  33 -       fb_info->node = i;
  34 +       if (!fb_info->custom_fb_num || fb_info->node >= FB_MAX || registered_fb[fb_info->node]) {
  35 +               for (i = min_dynamic_fb ; i < FB_MAX; i++)
  36 +                       if (!registered_fb[i])
  37 +                               break;
  38 +               fb_info->node = i;
  39 +       }
  40         refcount_set(&fb_info->count, 1);
  41         mutex_init(&fb_info->lock);
  42         mutex_init(&fb_info->mm_lock);
  43 @@ -976,7 +979,7 @@ static int do_register_framebuffer(struc
  44
  45         fb_var_to_videomode(&mode, &fb_info->var);
  46         fb_add_videomode(&mode, &fb_info->modelist);
  47 -       registered_fb[i] = fb_info;
  48 +       registered_fb[fb_info->node] = fb_info;
  49
  50  #ifdef CONFIG_GUMSTIX_AM200EPD
  51         {
  52 @@ -1037,6 +1040,12 @@ static void do_unregister_framebuffer(st
  53         put_fb_info(fb_info);
  54  }
  55
  56 +void fb_set_lowest_dynamic_fb(int min_fb_dev)
  57 +{
  58 +       min_dynamic_fb = min_fb_dev;
  59 +}
  60 +EXPORT_SYMBOL(fb_set_lowest_dynamic_fb);
  61 +
  62  /**
  63   *     register_framebuffer - registers a frame buffer device
  64   *     @fb_info: frame buffer info structure
  65 --- a/include/linux/fb.h
  66 +++ b/include/linux/fb.h
  67 @@ -501,6 +501,7 @@ struct fb_info {
  68         void *par;
  69
  70         bool skip_vt_switch; /* no VT switch on suspend/resume required */
  71 +       bool custom_fb_num; /* Use value in node as the preferred node number */
  72  };
  73
  74  /* This will go away
  75 @@ -589,6 +590,7 @@ extern ssize_t fb_sys_write(struct fb_in
  76         .fb_imageblit   = sys_imageblit
  77
  78  /* fbmem.c */
  79 +extern void fb_set_lowest_dynamic_fb(int min_fb_dev);
  80  extern int register_framebuffer(struct fb_info *fb_info);
  81  extern void unregister_framebuffer(struct fb_info *fb_info);
  82  extern int fb_prepare_logo(struct fb_info *fb_info, int rotate);