[PATCH v3] arm64: dts: qcom: sc8280xp: correct ref_aux clock for ufs_mem_phy

[Brian Masney]

The first UFS host controller fails to start on the SA8540P automotive
board (QDrive3) due to the following errors:

    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag_retry: query attribute, opcode 5, idn 18, failed
        with error 253 after 3 retries

The system eventually fails to boot with the warning:

    gcc_ufs_phy_axi_clk status stuck at 'off'

This issue can be worked around by adding clk_ignore_unused to the
kernel command line since the system firmware sets up this clock for us.

Let's fix this issue by updating the ref clock on ufs_mem_phy. Note
that the downstream MSM 5.4 sources list this as ref_clk_parent. With
this patch, the SA8540P is able to be booted without clk_ignore_unused.

Signed-off-by: Brian Masney <bmasney@xxxxxxxxxx>
Fixes: 152d1faf1e2f3 ("arm64: dts: qcom: add SC8280XP platform")
---
v2 of this patch can be found at
https://lore.kernel.org/lkml/20220825163755.683843-1-bmasney@xxxxxxxxxx/T/#u

v1 of this patch can be found at
https://lore.kernel.org/lkml/20220623142837.3140680-1-bmasney@xxxxxxxxxx/T/#u

Note that there's also a similar issue with the second UFS controller
(ufs_card_hc) since it separately fails with:

    ufshcd-qcom 1da4000.ufs: Controller enable failed
    ufshcd-qcom 1da4000.ufs: link startup failed 1
    ...
    gcc_ufs_card_axi_clk status stuck at 'off'

We are currently disabling the second UFS host controller (ufs_card_hc) in
our DTS at the moment. I haven't had any luck so far tracking this one
down and it's particularly tough without docs access.

 arch/arm64/boot/dts/qcom/sc8280xp.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
index 49ea8b5612fc..2bdde4b8f72b 100644
--- a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
@@ -891,7 +891,7 @@ ufs_mem_phy: phy@1d87000 {
 			ranges;
 			clock-names = "ref",
 				      "ref_aux";
-			clocks = <&rpmhcc RPMH_CXO_CLK>,
+			clocks = <&gcc GCC_UFS_REF_CLKREF_CLK>,
 				 <&gcc GCC_UFS_PHY_PHY_AUX_CLK>;
 
 			resets = <&ufs_mem_hc 0>;
-- 
2.37.1