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From: Romain Izard <romain.izard.pro@gmail.com>
To: Nicolas Ferre <nicolas.ferre@microchip.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Tudor Ambarus <Tudor.Ambarus@microchip.com>
Cc: Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Romain Izard <romain.izard.pro@gmail.com>
Subject: [PATCH] ARM: dts: at91: sama5d2: use the divided clock for SMC
Date: Tue, 20 Nov 2018 17:57:37 +0100	[thread overview]
Message-ID: <20181120165737.4998-1-romain.izard.pro@gmail.com> (raw)

The SAMA5D2 is different from SAMA5D3 and SAMA5D4, as there are two
different clocks for the peripherals in the SoC. The Static Memory
controller is connected to the divided master clock.

Unfortunately, the device tree does not correctly show this and uses the
master clock directly. This clock is then used by the code for the NAND
controller to calculate the timings for the controller, and we end up with
slow NAND Flash access.

Fix the device tree, and the performance of Flash access is improved.

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
---
 arch/arm/boot/dts/sama5d2.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/sama5d2.dtsi b/arch/arm/boot/dts/sama5d2.dtsi
index 61f68e5c48e9..b405992eb601 100644
--- a/arch/arm/boot/dts/sama5d2.dtsi
+++ b/arch/arm/boot/dts/sama5d2.dtsi
@@ -308,7 +308,7 @@
 				  0x1 0x0 0x60000000 0x10000000
 				  0x2 0x0 0x70000000 0x10000000
 				  0x3 0x0 0x80000000 0x10000000>;
-			clocks = <&mck>;
+			clocks = <&h32ck>;
 			status = "disabled";
 
 			nand_controller: nand-controller {
-- 
2.17.1


             reply	other threads:[~2018-11-20 16:58 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-20 16:57 Romain Izard [this message]
2018-11-20 17:16 ` [PATCH] ARM: dts: at91: sama5d2: use the divided clock for SMC Alexandre Belloni
2018-11-20 18:01   ` Romain Izard
2018-11-20 20:40     ` Alexandre Belloni
2018-11-21 11:00       ` Alexandre Belloni

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