linux-kernel - [PATCH v3 2/4] arm64: dts: qcom: sc7180: revert "arm64: dts: qcom: sc7180: Avoid glitching SPI CS at bootup on trogdor"

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Message-Id: <20221019001351.1630089-3-krzysztof.kozlowski@linaro.org>
Date:   Tue, 18 Oct 2022 20:13:49 -0400
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Bjorn Andersson <andersson@...nel.org>,
        Andy Gross <agross@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...ainline.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Matthias Kaehlcke <mka@...omium.org>,
        Douglas Anderson <dianders@...omium.org>,
        Stephen Boyd <swboyd@...omium.org>,
        linux-arm-msm@...r.kernel.org, linux-gpio@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
Subject: [PATCH v3 2/4] arm64: dts: qcom: sc7180: revert "arm64: dts: qcom: sc7180: Avoid glitching SPI CS at bootup on trogdor"

This reverts commit e440e30e26dd6b0424002ad0ddcbbcea783efd85 because it
is not a reliable way of fixing SPI CS glitch and it depends on specific
Linux kernel pin controller driver behavior.

This behavior of kernel driver was changed in commit b991f8c3622c
("pinctrl: core: Handling pinmux and pinconf separately") thus
effectively the DTS fix stopped being effective.

Proper solution for the glitching SPI chip select must be implemented in
the drivers, not via ordering of entries in DTS.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>

---

Changes since v2:
1. New patch

Not tested on hardware.

Cc: Doug Anderson <dianders@...omium.org>
---
 arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi | 27 +++-----------------
 1 file changed, 3 insertions(+), 24 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
index eae22e6e97c1..8f6e19bd6a99 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
@@ -880,17 +880,17 @@ &sdhc_2 {
 };
 
 &spi0 {
-	pinctrl-0 = <&qup_spi0_cs_gpio_init_high>, <&qup_spi0_cs_gpio>;
+	pinctrl-0 = <&qup_spi0_cs_gpio>;
 	cs-gpios = <&tlmm 37 GPIO_ACTIVE_LOW>;
 };
 
 &spi6 {
-	pinctrl-0 = <&qup_spi6_cs_gpio_init_high>, <&qup_spi6_cs_gpio>;
+	pinctrl-0 = <&qup_spi6_cs_gpio>;
 	cs-gpios = <&tlmm 62 GPIO_ACTIVE_LOW>;
 };
 
 ap_spi_fp: &spi10 {
-	pinctrl-0 = <&qup_spi10_cs_gpio_init_high>, <&qup_spi10_cs_gpio>;
+	pinctrl-0 = <&qup_spi10_cs_gpio>;
 	cs-gpios = <&tlmm 89 GPIO_ACTIVE_LOW>;
 
 	cros_ec_fp: ec@0 {
@@ -1422,27 +1422,6 @@ pinconf {
 		};
 	};
 
-	qup_spi0_cs_gpio_init_high: qup-spi0-cs-gpio-init-high {
-		pinconf {
-			pins = "gpio37";
-			output-high;
-		};
-	};
-
-	qup_spi6_cs_gpio_init_high: qup-spi6-cs-gpio-init-high {
-		pinconf {
-			pins = "gpio62";
-			output-high;
-		};
-	};
-
-	qup_spi10_cs_gpio_init_high: qup-spi10-cs-gpio-init-high {
-		pinconf {
-			pins = "gpio89";
-			output-high;
-		};
-	};
-
 	qup_uart3_sleep: qup-uart3-sleep {
 		pinmux {
 			pins = "gpio38", "gpio39",
-- 
2.34.1