[PATCH] ARM: dts: stm32: Adjust PLL4 settings on AV96 again

Marek Vasut marex at denx.de
Sat Aug 22 22:45:25 CEST 2020


PLL4Q is supplying both FDCAN and LTDC. In case HDMI is in use, the
50 MHz generated from PLL4Q cannot be divided well enough to produce
accurate clock for HDMI pixel clock. Adjust it to generate 74.25 MHz
instead. The PLL4P/PLL4R are generating 99 MHz instead of 100 MHz,
which is in tolerance for the SDMMC.

Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Gerald Baeza <gerald.baeza at st.com>
Cc: Patrick Delaunay <patrick.delaunay at st.com>
Cc: Patrice Chotard <patrice.chotard at st.com>
---
NOTE: Thanks to Gerald for this suggestion.
---
 arch/arm/dts/stm32mp15xx-dhcor-u-boot.dtsi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/dts/stm32mp15xx-dhcor-u-boot.dtsi b/arch/arm/dts/stm32mp15xx-dhcor-u-boot.dtsi
index 7529068c51..c73318488d 100644
--- a/arch/arm/dts/stm32mp15xx-dhcor-u-boot.dtsi
+++ b/arch/arm/dts/stm32mp15xx-dhcor-u-boot.dtsi
@@ -132,11 +132,11 @@
 		u-boot,dm-pre-reloc;
 	};
 
-	/* VCO = 600.0 MHz => P = 100, Q = 50, R = 100 */
+	/* VCO = 600.0 MHz => P = 99, Q = 74, R = 99 */
 	pll4: st,pll at 3 {
 		compatible = "st,stm32mp1-pll";
 		reg = <3>;
-		cfg = < 1 49 5 11 5 PQR(1,1,1) >;
+		cfg = < 3 98 5 7 5 PQR(1,1,1) >;
 		u-boot,dm-pre-reloc;
 	};
 };
-- 
2.28.0



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