google/pit: disable SYSMMU for graphics
It's not needed and it's a potential problem source.
Change-Id: Ic4cafe74e7fc3a9031d852895ad7fd5e5cd64d11
Signed-off-by: Ronald G. Minnich <rminnich@google.com>
Reviewed-on: https://gerrit.chromium.org/gerrit/62279
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/4410
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
diff --git a/src/mainboard/google/pit/mainboard.c b/src/mainboard/google/pit/mainboard.c
index 2870467..d0230e2 100644
--- a/src/mainboard/google/pit/mainboard.c
+++ b/src/mainboard/google/pit/mainboard.c
@@ -326,6 +326,15 @@
fb_addr = cbmem_find(CBMEM_ID_CONSOLE);
set_vbe_mode_info_valid(&edid, (uintptr_t)fb_addr);
+ /*
+ * The reset value for FIMD SYSMMU register MMU_CTRL:0x14640000
+ * should be 0 according to the datasheet, but has experimentally
+ * been found to come up as 3. This means FIMD SYSMMU is on by
+ * default on Exynos5420. For now we are disabling FIMD SYSMMU.
+ */
+ writel(0x0, (void *)0x14640000);
+ writel(0x0, (void *)0x14680000);
+
lcd_vdd();
parade_dp_bridge_setup();