[PATCH v2] arm64: dts: imx8mq: Add clock parents for mipi dphy

From: Guido Günther
Date: Sun Jan 10 2021 - 11:56:37 EST


This makes sure the clock tree setup for the dphy is not dependent on
other components.

Without this change bringing up the display can fail like

kernel: phy phy-30a00300.dphy.2: Invalid CM/CN/CO values: 165/217/1
kernel: phy phy-30a00300.dphy.2: for hs_clk/ref_clk=451656000/593999998 ~ 165/217

if LCDIF doesn't set up that part of the clock tree first. This was
noticed when testing the Librem 5 devkit with defconfig. It doesn't
happen when modules are built in.

Signed-off-by: Guido Günther <agx@xxxxxxxxxxx>

---
Changes from v1:
- as per review comment from Shawn Guo
https://lore.kernel.org/linux-arm-kernel/20210110124629.GO28365@dragon/
Set clock rate for IMX8MQ_VIDEO_PLL1 too. Otherwise we end up with
a close but not exact clock rate.

arch/arm64/boot/dts/freescale/imx8mq.dtsi | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mq.dtsi b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
index a841a023e8e0..50ae17f65a51 100644
--- a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
@@ -1016,9 +1016,14 @@ dphy: dphy@30a00300 {
reg = <0x30a00300 0x100>;
clocks = <&clk IMX8MQ_CLK_DSI_PHY_REF>;
clock-names = "phy_ref";
- assigned-clocks = <&clk IMX8MQ_CLK_DSI_PHY_REF>;
- assigned-clock-parents = <&clk IMX8MQ_VIDEO_PLL1_OUT>;
- assigned-clock-rates = <24000000>;
+ assigned-clocks = <&clk IMX8MQ_VIDEO_PLL1_REF_SEL>,
+ <&clk IMX8MQ_VIDEO_PLL1_BYPASS>,
+ <&clk IMX8MQ_CLK_DSI_PHY_REF>,
+ <&clk IMX8MQ_VIDEO_PLL1>;
+ assigned-clock-parents = <&clk IMX8MQ_CLK_25M>,
+ <&clk IMX8MQ_VIDEO_PLL1>,
+ <&clk IMX8MQ_VIDEO_PLL1_OUT>;
+ assigned-clock-rates = <0>, <0>, <24000000>, <594000000>;
#phy-cells = <0>;
power-domains = <&pgc_mipi>;
status = "disabled";
--
2.29.2