ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines
authorTudor Ambarus <tudor.ambarus@microchip.com>
Wed, 6 Apr 2022 13:05:05 +0000 (16:05 +0300)
committerNicolas Ferre <nicolas.ferre@microchip.com>
Wed, 13 Apr 2022 16:42:50 +0000 (18:42 +0200)
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>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20220406130505.422042-1-tudor.ambarus@microchip.com
arch/arm/boot/dts/at91-sama7g5ek.dts

index dd047a8..d83f76a 100644 (file)
                         <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 {