[PATCH V2 1/2] arm64: dts: imx8mp: Fix SDMA2/3 clocks

[Adam Ford]

A previous patch to remove the Audio clocks from the main clock node
was intended to force people to setup the audio PLL clocks per board
instead of having a common set of rates since not all boards may use
the various audio PLL clocks for audio devices.

Unfortunately, with this parenting removed, the SDMA2 and SDMA3
clocks were slowed to 24MHz because the SDMA2/3 clocks are controlled
via the audio_blk_ctrl which is clocked from IMX8MP_CLK_AUDIO_ROOT,
and that clock is enabled by pgc_audio.

Per the TRM, "The SDMA2/3 target frequency is 400MHz IPG and 400MHz
AHB, always 1:1 mode, to make sure there is enough throughput for all
the audio use cases."

Instead of cluttering the clock node, place the clock rate and parent
information into the pgc_audio node.

With the parenting and clock rates restored for  IMX8MP_CLK_AUDIO_AHB,
and IMX8MP_CLK_AUDIO_AXI_SRC, it appears the SDMA2 and SDMA3 run at
400MHz again.

Fixes: 16c984524862 ("arm64: dts: imx8mp: don't initialize audio clocks from CCM node")
Signed-off-by: Adam Ford <aford173 at gmail.com>
Reviewed-by: Lucas Stach <l.stach at pengutronix.de>
---

V2:  Slow AUDIO_AXI to 600MHz for nominal drive.  Individual boards can increase
     this to 800MHz if they have the proper voltage configured.

diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
index 6f2f50e1639c..83d907294fbc 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
@@ -790,6 +790,12 @@ pgc_audio: power-domain at 5 {
 						reg = <IMX8MP_POWER_DOMAIN_AUDIOMIX>;
 						clocks = <&clk IMX8MP_CLK_AUDIO_ROOT>,
 							 <&clk IMX8MP_CLK_AUDIO_AXI>;
+						assigned-clocks = <&clk IMX8MP_CLK_AUDIO_AHB>,
+								  <&clk IMX8MP_CLK_AUDIO_AXI_SRC>;
+						assigned-clock-parents =  <&clk IMX8MP_SYS_PLL1_800M>,
+									  <&clk IMX8MP_SYS_PLL1_800M>;
+						assigned-clock-rates = <400000000>,
+								       <600000000>;
 					};
 
 					pgc_gpu2d: power-domain at 6 {
-- 
2.39.2