boot/fdt_simplefb.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Simplefb device tree support
   4  *
   5  * (C) Copyright 2015
   6  * Stephen Warren <swarren@wwwdotorg.org>
   7  */
   8
   9 #include <common.h>
  10 #include <dm.h>
  11 #include <fdt_support.h>
  12 #include <asm/global_data.h>
  13 #include <linux/libfdt.h>
  14 #include <video.h>
  15
  16 DECLARE_GLOBAL_DATA_PTR;
  17
  18 static int fdt_simplefb_configure_node(void *blob, int off)
  19 {
  20         int xsize, ysize;
  21         int bpix; /* log2 of bits per pixel */
  22         const char *name;
  23         ulong fb_base;
  24         struct video_uc_plat *plat;
  25         struct video_priv *uc_priv;
  26         struct udevice *dev;
  27         int ret;
  28
  29         ret = uclass_first_device_err(UCLASS_VIDEO, &dev);
  30         if (ret)
  31                 return ret;
  32         uc_priv = dev_get_uclass_priv(dev);
  33         plat = dev_get_uclass_plat(dev);
  34         xsize = uc_priv->xsize;
  35         ysize = uc_priv->ysize;
  36         bpix = uc_priv->bpix;
  37         fb_base = plat->base;
  38         switch (bpix) {
  39         case 4: /* VIDEO_BPP16 */
  40                 name = "r5g6b5";
  41                 break;
  42         case 5: /* VIDEO_BPP32 */
  43                 name = "a8r8g8b8";
  44                 break;
  45         default:
  46                 return -EINVAL;
  47         }
  48
  49         return fdt_setup_simplefb_node(blob, off, fb_base, xsize, ysize,
  50                                        xsize * (1 << bpix) / 8, name);
  51 }
  52
  53 int fdt_simplefb_add_node(void *blob)
  54 {
  55         static const char compat[] = "simple-framebuffer";
  56         static const char disabled[] = "disabled";
  57         int off, ret;
  58
  59         off = fdt_add_subnode(blob, 0, "framebuffer");
  60         if (off < 0)
  61                 return -1;
  62
  63         ret = fdt_setprop(blob, off, "status", disabled, sizeof(disabled));
  64         if (ret < 0)
  65                 return -1;
  66
  67         ret = fdt_setprop(blob, off, "compatible", compat, sizeof(compat));
  68         if (ret < 0)
  69                 return -1;
  70
  71         return fdt_simplefb_configure_node(blob, off);
  72 }
  73
  74 /**
  75  * fdt_simplefb_enable_existing_node() - enable simple-framebuffer DT node
  76  *
  77  * @blob:       device-tree
  78  * Return:      0 on success, non-zero otherwise
  79  */
  80 static int fdt_simplefb_enable_existing_node(void *blob)
  81 {
  82         int off;
  83
  84         off = fdt_node_offset_by_compatible(blob, -1, "simple-framebuffer");
  85         if (off < 0)
  86                 return -1;
  87
  88         return fdt_simplefb_configure_node(blob, off);
  89 }
  90
  91 #if IS_ENABLED(CONFIG_VIDEO)
  92 int fdt_simplefb_enable_and_mem_rsv(void *blob)
  93 {
  94         struct fdt_memory mem;
  95         int ret;
  96
  97         /* nothing to do when video is not active */
  98         if (!video_is_active())
  99                 return 0;
 100
 101         ret = fdt_simplefb_enable_existing_node(blob);
 102         if (ret)
 103                 return ret;
 104
 105         /* nothing to do when the frame buffer is not defined */
 106         if (gd->video_bottom == gd->video_top)
 107                 return 0;
 108
 109         /* reserved with no-map tag the video buffer */
 110         mem.start = gd->video_bottom;
 111         mem.end = gd->video_top - 1;
 112
 113         return fdtdec_add_reserved_memory(blob, "framebuffer", &mem, NULL, 0, NULL,
 114                                           FDTDEC_RESERVED_MEMORY_NO_MAP);
 115 }
 116 #endif