sunxi: video: Dynamically reserve framebuffer memory

Only use CONFIG_SUNXI_MAX_FB_SIZE to reserve memory at the top when relocating
u-boot, and calculate the actual amount of memory necessary when setting up
the video-mode and use only that, freeing up some additional memory for use
by the kernel.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

diff --git a/drivers/video/sunxi_display.c b/drivers/video/sunxi_display.c
index cd5963a75141d1f10722091688023a556f12e22a..dbda97e746b97b5dc2a729198738c449e59163c7 100644 (file)
--- a/drivers/video/sunxi_display.c
+++ b/drivers/video/sunxi_display.c
@@ -46,6 +46,7 @@ struct sunxi_display {
        GraphicDevice graphic_device;
        enum sunxi_monitor monitor;
        unsigned int depth;
+       unsigned int fb_size;
 } sunxi_display;
 
 #ifdef CONFIG_VIDEO_HDMI
@@ -1080,10 +1081,6 @@ void *video_hw_init(void)
 
        memset(&sunxi_display, 0, sizeof(struct sunxi_display));
 
-       printf("Reserved %dkB of RAM for Framebuffer.\n",
-              CONFIG_SUNXI_MAX_FB_SIZE >> 10);
-       gd->fb_base = gd->ram_top;
-
        video_get_ctfb_res_modes(RES_MODE_1024x768, 24, &mode,
                                 &sunxi_display.depth, &options);
 #ifdef CONFIG_VIDEO_HDMI
@@ -1174,6 +1171,17 @@ void *video_hw_init(void)
                       mode->yres, sunxi_get_mon_desc(sunxi_display.monitor));
        }
 
+       sunxi_display.fb_size =
+               (mode->xres * mode->yres * 4 + 0xfff) & ~0xfff;
+       if (sunxi_display.fb_size > CONFIG_SUNXI_MAX_FB_SIZE) {
+               printf("Error need %dkB for fb, but only %dkB is reserved\n",
+                      sunxi_display.fb_size >> 10,
+                      CONFIG_SUNXI_MAX_FB_SIZE >> 10);
+               return NULL;
+       }
+
+       gd->fb_base = gd->bd->bi_dram[0].start +
+                     gd->bd->bi_dram[0].size - sunxi_display.fb_size;
        sunxi_engines_init();
        sunxi_mode_set(mode, gd->fb_base - CONFIG_SYS_SDRAM_BASE);
 
@@ -1250,7 +1258,7 @@ int sunxi_simplefb_setup(void *blob)
         * linux/arch/arm/mm/ioremap.c around line 301.
         */
        start = gd->bd->bi_dram[0].start;
-       size = gd->bd->bi_dram[0].size - CONFIG_SUNXI_MAX_FB_SIZE;
+       size = gd->bd->bi_dram[0].size - sunxi_display.fb_size;
        ret = fdt_fixup_memory_banks(blob, &start, &size, 1);
        if (ret) {
                eprintf("Cannot setup simplefb: Error reserving memory\n");