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From:   Tudor Ambarus <tudor.ambarus@microchip.com>
To:     <nicolas.ferre@microchip.com>, <claudiu.beznea@microchip.com>
CC:     <alexandre.belloni@bootlin.com>, <devicetree@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>,
        "Tudor Ambarus" <tudor.ambarus@microchip.com>,
        Mihai Sain <mihai.sain@microchip.com>
Subject: [PATCH] ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines
Date:   Wed, 6 Apr 2022 16:05:05 +0300
Message-ID: <20220406130505.422042-1-tudor.ambarus@microchip.com>
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The impedance of the QSPI PCB lines on the sama7g5ek is 50 Ohms.
Align the output impedance of the QSPI0 HSIOs by setting a medium drive
strength which corresponds to an impedance of 56 Ohms when VDD is in the
3.0V - 3.6V range. The high drive strength setting corresponds to an
output impedance of 42 Ohms on the QSPI0 HSIOs.

Suggested-by: Mihai Sain <mihai.sain@microchip.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
---
 arch/arm/boot/dts/at91-sama7g5ek.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
index 08685a10eda1..8f9643170ba3 100644
--- a/arch/arm/boot/dts/at91-sama7g5ek.dts
+++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
@@ -655,7 +655,7 @@ pinctrl_qspi: qspi {
 			 <PIN_PB21__QSPI0_INT>;
 		bias-disable;
 		slew-rate = <0>;
-		atmel,drive-strength = <ATMEL_PIO_DRVSTR_HI>;
+		atmel,drive-strength = <ATMEL_PIO_DRVSTR_ME>;
 	};
 
 	pinctrl_sdmmc0_default: sdmmc0_default {
-- 
2.25.1