video: fsl_dcu_fb: fix framebuffer to the end of memory
Fix the framebuffer location to the very end of the available memory.
This allows to remove the area from available memory for the kernel,
which in turn allows to display the splash screen through the Linux
kernel boot process.
Ideas has been taken from the sunxi display driver, e.g.
20779ec3a5 ("sunxi: video: Dynamically reserve framebuffer memory")
Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
diff --git a/drivers/video/fsl_dcu_fb.c b/drivers/video/fsl_dcu_fb.c
index d4cd382..7f03290 100644
--- a/drivers/video/fsl_dcu_fb.c
+++ b/drivers/video/fsl_dcu_fb.c
@@ -8,6 +8,7 @@
#include <asm/io.h>
#include <common.h>
+#include <fdt_support.h>
#include <fsl_dcu_fb.h>
#include <linux/fb.h>
#include <malloc.h>
@@ -79,6 +80,8 @@
#define BPP_24_RGB888 5
#define BPP_32_ARGB8888 6
+DECLARE_GLOBAL_DATA_PTR;
+
/*
* This setting is used for the TWR_LCD_RGB card
*/
@@ -254,11 +257,19 @@
struct dcu_reg *regs = (struct dcu_reg *)CONFIG_SYS_DCU_ADDR;
unsigned int div, mode;
- /* Memory allocation for framebuffer */
info.screen_size =
info.var.xres * info.var.yres * (info.var.bits_per_pixel / 8);
- info.screen_base = (char *)memalign(ARCH_DMA_MINALIGN,
- roundup(info.screen_size, ARCH_DMA_MINALIGN));
+
+ if (info.screen_size > CONFIG_VIDEO_FSL_DCU_MAX_FB_SIZE_MB) {
+ info.screen_size = 0;
+ return -ENOMEM;
+ }
+
+ /* Reserve framebuffer at the end of memory */
+ gd->fb_base = gd->bd->bi_dram[0].start +
+ gd->bd->bi_dram[0].size - info.screen_size;
+ info.screen_base = (char *)gd->fb_base;
+
memset(info.screen_base, 0, info.screen_size);
reset_total_layers();
@@ -305,6 +316,11 @@
return 0;
}
+ulong board_get_usable_ram_top(ulong total_size)
+{
+ return gd->ram_top - CONFIG_VIDEO_FSL_DCU_MAX_FB_SIZE_MB;
+}
+
void *video_hw_init(void)
{
static GraphicDevice ctfb;
@@ -363,3 +379,26 @@
return &ctfb;
}
+
+#if defined(CONFIG_OF_BOARD_SETUP)
+int fsl_dcu_fixedfb_setup(void *blob)
+{
+ u64 start, size;
+ int ret;
+
+ start = gd->bd->bi_dram[0].start;
+ size = gd->bd->bi_dram[0].size - info.screen_size;
+
+ /*
+ * Align size on section size (1 MiB).
+ */
+ size &= 0xfff00000;
+ ret = fdt_fixup_memory_banks(blob, &start, &size, 1);
+ if (ret) {
+ eprintf("Cannot setup fb: Error reserving memory\n");
+ return ret;
+ }
+
+ return 0;
+}
+#endif