On the Amlogic G12A SoC family, (only) the SDIO controller has a bug which
makes any DRAM access from the MMC controller fail.
Add the amlogic,dram-access-quirk property so signal this particular
controller has this bug and needs a quirk to work properly.
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt b/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt
index 13e70409e8ac..ccc5358db131 100644
--- a/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt
+++ b/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt
@@ -22,6 +22,10 @@ Required properties:
clock rate requested by the MMC core.
- resets : phandle of the internal reset line
+Optional properties:
+- amlogic,dram-access-quirk: set when controller's internal DMA engine cannot access the
+ DRAM memory, like on the G12A dedicated SDIO controller.
+
Example:
sd_emmc_a: mmc@70000 {
--
2.21.0
