arm64: dts: mediatek: mt8173: Reserve memory for audio frontend

Some MediaTek platforms already reserve a small block of memory for the
audio frontend. These platforms reserve it at a fixed address, though it
is unclear if that is due to hardware access restrictions or simply
compacting the reserved memory blocks together.

Reserve the same size of memory on the MT8173 as well, to align with the
other platforms. This also helps with memory starvation as these devices
commonly end up in low memory conditions.

Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20250424102509.1083185-11-wenst@chromium.org
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

diff --git a/arch/arm64/boot/dts/mediatek/mt8173.dtsi b/arch/arm64/boot/dts/mediatek/mt8173.dtsi
index 6d1d8877b43f24d65a90401226e14a200778ee57..122a57c3780b69ac25bb114193814f68dac43791 100644 (file)
--- a/arch/arm64/boot/dts/mediatek/mt8173.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8173.dtsi
@@ -318,6 +318,14 @@
                #address-cells = <2>;
                #size-cells = <2>;
                ranges;
+
+               afe_dma_mem: audio-dma-pool {
+                       compatible = "shared-dma-pool";
+                       size = <0 0x100000>;
+                       alignment = <0 0x10>;
+                       no-map;
+               };
+
                vpu_dma_reserved: vpu-dma-mem@b7000000 {
                        compatible = "shared-dma-pool";
                        reg = <0 0xb7000000 0 0x500000>;
@@ -887,6 +895,7 @@
                                          <&topckgen CLK_TOP_AUD_2_SEL>;
                        assigned-clock-parents = <&topckgen CLK_TOP_APLL1>,
                                                 <&topckgen CLK_TOP_APLL2>;
+                       memory-region = <&afe_dma_mem>;
                };
 
                mmc0: mmc@11230000 {