[PATCH v2 01/14] ARM: dts: imx6ull-colibri: use pull-down for adc pins

From: Marcel Ziswiler
Date: Mon Apr 25 2022 - 12:26:33 EST


From: Philippe Schenker <philippe.schenker@xxxxxxxxxxx>

Disable the keeper and enable a 100k pull-down on the ADC pins as per
the following note in section 13.2 of the i.MX 6ULL Application
Processor Reference Manual, Rev. 1, 11/2017 [1]:

The keeper causes an undesired jump behavior in ADC. To avoid the
problem, disable keeper before starting ADC.

[1] https://www.nxp.com/webapp/Download?colCode=IMX6ULLRM

Signed-off-by: Philippe Schenker <philippe.schenker@xxxxxxxxxxx>
Signed-off-by: Denys Drozdov <denys.drozdov@xxxxxxxxxxx>
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
---

(no changes since v1)

arch/arm/boot/dts/imx6ull-colibri.dtsi | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/arch/arm/boot/dts/imx6ull-colibri.dtsi b/arch/arm/boot/dts/imx6ull-colibri.dtsi
index 951a2a6c5a65..eb13ed60d2e4 100644
--- a/arch/arm/boot/dts/imx6ull-colibri.dtsi
+++ b/arch/arm/boot/dts/imx6ull-colibri.dtsi
@@ -52,6 +52,8 @@ reg_sd1_vmmc: regulator-sd1-vmmc {
&adc1 {
num-channels = <10>;
vref-supply = <&reg_module_3v3_avdd>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_adc1>;
};

&can1 {
@@ -214,6 +216,16 @@ &wdog1 {
};

&iomuxc {
+
+ pinctrl_adc1: adc1grp {
+ fsl,pins = <
+ MX6UL_PAD_GPIO1_IO00__GPIO1_IO00 0x3000 /* SODIMM 8 */
+ MX6UL_PAD_GPIO1_IO01__GPIO1_IO01 0x3000 /* SODIMM 6 */
+ MX6UL_PAD_GPIO1_IO08__GPIO1_IO08 0x3000 /* SODIMM 4 */
+ MX6UL_PAD_GPIO1_IO09__GPIO1_IO09 0x3000 /* SODIMM 2 */
+ >;
+ };
+
pinctrl_can_int: canint-grp {
fsl,pins = <
MX6UL_PAD_ENET1_TX_DATA1__GPIO2_IO04 0x13010 /* SODIMM 73 */
--
2.35.1