[PATCH 2/2] ARM: dts: at91: sama7g5ek: to not touch slew-rate for SDMMC pins
flat view
STALE1843d
LANDED
From: Claudiu Beznea <hidden>
Date: 2021-09-15 07:49:17
Also in:
linux-devicetree, lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
Landed in mainline as dbe68bc9e82b on 2021-10-04.
With commit c709135e576b ("pinctrl: at91-pio4: add support for slew-rate")
and commit cbde6c823bfa ("pinctrl: at91-pio4: Fix slew rate disablement")
the slew-rate is enabled by default for each configured pin. The datasheet
specifies at chapter "Output Driver AC Characteristics" that HSIO
drivers (use in SDMMCx and QSPI0 peripherals), don't have a slewrate
setting but are rather calibrated against an external 1% resistor mounted
on the SDMMCx_CAL or QSPI0_CAL pins. Depending on the target signal
frequency and the external load, it is possible to adjust their target
output impedance. Thus set slew-rate = <0> for SDMMC (QSPI is not enabled
at the moment in device tree).
Fixes: 7540629e2fc7 ("ARM: dts: at91: add sama7g5 SoC DT and sama7g5-ek")
Signed-off-by: Claudiu Beznea <redacted>
---
arch/arm/boot/dts/at91-sama7g5ek.dts | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
index 0bed8207d498..624162fec223 100644
--- a/arch/arm/boot/dts/at91-sama7g5ek.dts
+++ b/arch/arm/boot/dts/at91-sama7g5ek.dts@@ -556,6 +556,7 @@ cmd_data { <PIN_PA8__SDMMC0_DAT5>, <PIN_PA9__SDMMC0_DAT6>, <PIN_PA10__SDMMC0_DAT7>; + slew-rate = <0>; bias-pull-up; };
@@ -563,6 +564,7 @@ ck_cd_rstn_vddsel { pinmux = <PIN_PA0__SDMMC0_CK>, <PIN_PA2__SDMMC0_RSTN>, <PIN_PA11__SDMMC0_DS>; + slew-rate = <0>; bias-pull-up; }; };
@@ -574,6 +576,7 @@ cmd_data { <PIN_PC0__SDMMC1_DAT1>, <PIN_PC1__SDMMC1_DAT2>, <PIN_PC2__SDMMC1_DAT3>; + slew-rate = <0>; bias-pull-up; };
@@ -582,6 +585,7 @@ ck_cd_rstn_vddsel { <PIN_PB28__SDMMC1_RSTN>, <PIN_PC5__SDMMC1_1V8SEL>, <PIN_PC4__SDMMC1_CD>; + slew-rate = <0>; bias-pull-up; }; };
@@ -593,11 +597,13 @@ cmd_data { <PIN_PD6__SDMMC2_DAT1>, <PIN_PD7__SDMMC2_DAT2>, <PIN_PD8__SDMMC2_DAT3>; + slew-rate = <0>; bias-pull-up; }; ck { pinmux = <PIN_PD4__SDMMC2_CK>; + slew-rate = <0>; bias-pull-up; }; };
--
2.25.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel