diff mbox series

[V3,13/14] ARM: dts: stm32: Adjust PLL4 settings on AV96

Message ID 20200331175136.205020-14-marex@denx.de
State Accepted
Commit e5899099ab33993fa3f1ae8fe263613681b4916a
Headers show
Series ARM: stm32: Fix Avenger96 | expand

Commit Message

Marek Vasut March 31, 2020, 5:51 p.m. UTC 
The PLL4 is supplying SDMMC12, SDMMC3 and SPDIF with 120 MHz and
FDCAN with 96 MHz. This isn't good for the SDMMC interfaces, which
can not easily divide the clock down to e.g. 50 MHz for high speed
SD and eMMC devices, so those devices end up running at 30 MHz as
that is 120 MHz / 4. Adjust the PLL4 settings such that both PLL4P
and PLL4R run at 100 MHz instead, which is easy to divide to 50MHz
for optimal operation of both SD and eMMC, SPDIF clock are not that
much slower and FDCAN is also unaffected.

Reviewed-by: Patrice Chotard <patrice.chotard at st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay at st.com>
Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
Cc: Patrick Delaunay <patrick.delaunay at st.com>
Cc: Patrice Chotard <patrice.chotard at st.com>
---
V2: Move this patch before the split of AV96 into SoM and carrier
V3: No change
---
 arch/arm/dts/stm32mp157a-avenger96-u-boot.dtsi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm/dts/stm32mp157a-avenger96-u-boot.dtsi b/arch/arm/dts/stm32mp157a-avenger96-u-boot.dtsi
index 2c7dc509a3..320132a01e 100644
--- a/arch/arm/dts/stm32mp157a-avenger96-u-boot.dtsi
+++ b/arch/arm/dts/stm32mp157a-avenger96-u-boot.dtsi
@@ -130,11 +130,11 @@ 
 		u-boot,dm-pre-reloc;
 	};
 
-	/* VCO = 480.0 MHz => P = 120, Q = 40, R = 96 */
+	/* VCO = 600.0 MHz => P = 100, Q = 50, R = 100 */
 	pll4: st,pll at 3 {
 		compatible = "st,stm32mp1-pll";
 		reg = <3>;
-		cfg = < 1 39 3 11 4 PQR(1,1,1) >;
+		cfg = < 1 49 5 11 5 PQR(1,1,1) >;
 		u-boot,dm-pre-reloc;
 	};
 };