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From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Magnus Damm <magnus.damm@gmail.com>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	linux-renesas-soc@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH] arm64: dts: renesas: r8a779g0: Fix HSCIF0 "brg_int" clock
Date: Fri,  7 Oct 2022 17:20:03 +0200	[thread overview]
Message-ID: <a5bd4148f92806f7c8e577d383370f810315f586.1665155947.git.geert+renesas@glider.be> (raw)

As serial communication requires a clock signal, the High Speed Serial
Communication Interfaces with FIFO (HSCIF) are clocked by a clock that
is not affected by Spread Spectrum or Fractional Multiplication.

Hence change the clock input for the HSCIF0 Baud Rate Generator internal
clock from the S0D3_PER clock to the SASYNCPERD1 clock (which has the
same clock rate), cfr. R-Car V4H Hardware User's Manual rev. 0.54.

Fixes: 987da486d84a5643 ("arm64: dts: renesas: Add Renesas R8A779G0 SoC support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
For full proper operation, this depends on "[PATCH 1/5] clk: renesas:
r8a779g0: Add SASYNCPER clocks"[1].
However, as the "brg_int" clock is optional, the serial driver will keep
on functioning without it, and just resort to a less optimal clock
input/divider combination, which is still good enough for the serial
console.

[1] https://lore.kernel.org/r/d0f35c35e1f96c5a649ab477e7ba5d8025957cd0.1665147497.git.geert+renesas@glider.be
---
 arch/arm64/boot/dts/renesas/r8a779g0.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/renesas/r8a779g0.dtsi b/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
index edabd1519ccc979d..c941054f4980667b 100644
--- a/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
+++ b/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
@@ -360,7 +360,7 @@ hscif0: serial@e6540000 {
 			reg = <0 0xe6540000 0 96>;
 			interrupts = <GIC_SPI 246 IRQ_TYPE_LEVEL_HIGH>;
 			clocks = <&cpg CPG_MOD 514>,
-				 <&cpg CPG_CORE R8A779G0_CLK_S0D3_PER>,
+				 <&cpg CPG_CORE R8A779G0_CLK_SASYNCPERD1>,
 				 <&scif_clk>;
 			clock-names = "fck", "brg_int", "scif_clk";
 			dmas = <&dmac0 0x31>, <&dmac0 0x30>,
-- 
2.25.1


WARNING: multiple messages have this Message-ID (diff)
From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Magnus Damm <magnus.damm@gmail.com>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	linux-renesas-soc@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH] arm64: dts: renesas: r8a779g0: Fix HSCIF0 "brg_int" clock
Date: Fri,  7 Oct 2022 17:20:03 +0200	[thread overview]
Message-ID: <a5bd4148f92806f7c8e577d383370f810315f586.1665155947.git.geert+renesas@glider.be> (raw)

As serial communication requires a clock signal, the High Speed Serial
Communication Interfaces with FIFO (HSCIF) are clocked by a clock that
is not affected by Spread Spectrum or Fractional Multiplication.

Hence change the clock input for the HSCIF0 Baud Rate Generator internal
clock from the S0D3_PER clock to the SASYNCPERD1 clock (which has the
same clock rate), cfr. R-Car V4H Hardware User's Manual rev. 0.54.

Fixes: 987da486d84a5643 ("arm64: dts: renesas: Add Renesas R8A779G0 SoC support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
For full proper operation, this depends on "[PATCH 1/5] clk: renesas:
r8a779g0: Add SASYNCPER clocks"[1].
However, as the "brg_int" clock is optional, the serial driver will keep
on functioning without it, and just resort to a less optimal clock
input/divider combination, which is still good enough for the serial
console.

[1] https://lore.kernel.org/r/d0f35c35e1f96c5a649ab477e7ba5d8025957cd0.1665147497.git.geert+renesas@glider.be
---
 arch/arm64/boot/dts/renesas/r8a779g0.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/renesas/r8a779g0.dtsi b/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
index edabd1519ccc979d..c941054f4980667b 100644
--- a/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
+++ b/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
@@ -360,7 +360,7 @@ hscif0: serial@e6540000 {
 			reg = <0 0xe6540000 0 96>;
 			interrupts = <GIC_SPI 246 IRQ_TYPE_LEVEL_HIGH>;
 			clocks = <&cpg CPG_MOD 514>,
-				 <&cpg CPG_CORE R8A779G0_CLK_S0D3_PER>,
+				 <&cpg CPG_CORE R8A779G0_CLK_SASYNCPERD1>,
 				 <&scif_clk>;
 			clock-names = "fck", "brg_int", "scif_clk";
 			dmas = <&dmac0 0x31>, <&dmac0 0x30>,
-- 
2.25.1


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             reply	other threads:[~2022-10-07 15:20 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-07 15:20 Geert Uytterhoeven [this message]
2022-10-07 15:20 ` [PATCH] arm64: dts: renesas: r8a779g0: Fix HSCIF0 "brg_int" clock Geert Uytterhoeven
2022-10-10  7:55 ` Wolfram Sang
2022-10-10  7:55   ` Wolfram Sang
2022-10-10 11:12   ` Geert Uytterhoeven
2022-10-10 11:12     ` Geert Uytterhoeven

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