From: Marek Behún Date: Wed, 24 Nov 2021 22:49:33 +0000 (+0100) Subject: arm64: dts: marvell: armada-37xx: Set pcie_reset_pin to gpio function X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c755a93aa05e6e4ccdd3a5e921c0dd36f5c22c8b;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git arm64: dts: marvell: armada-37xx: Set pcie_reset_pin to gpio function commit 715878016984b2617f6c1f177c50039e12e7bd5b upstream. We found out that we are unable to control the PERST# signal via the default pin dedicated to be PERST# pin (GPIO2[3] pin) on A3700 SOC when this pin is in EP_PCIE1_Resetn mode. There is a register in the PCIe register space called PERSTN_GPIO_EN (D0088004[3]), but changing the value of this register does not change the pin output when measuring with voltmeter. We do not know if this is a bug in the SOC, or if it works only when PCIe controller is in a certain state. Commit f4c7d053d7f7 ("PCI: aardvark: Wait for endpoint to be ready before training link") says that when this pin changes pinctrl mode from EP_PCIE1_Resetn to GPIO, the PERST# signal is asserted for a brief moment. So currently the situation is that on A3700 boards the PERST# signal is asserted in U-Boot (because the code in U-Boot issues reset via this pin via GPIO mode), and then in Linux by the obscure and undocumented mechanism described by the above mentioned commit. We want to issue PERST# signal in a known way, therefore this patch changes the pcie_reset_pin function from "pcie" to "gpio" and adds the reset-gpios property to the PCIe node in device tree files of EspressoBin and Armada 3720 Dev Board (Turris Mox device tree already has this property and uDPU does not have a PCIe port). Signed-off-by: Marek Behún Cc: Remi Pommarel Tested-by: Tomasz Maciej Nowak Acked-by: Thomas Petazzoni Signed-off-by: Gregory CLEMENT Signed-off-by: Marek Behún Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/arm64/boot/dts/marvell/armada-3720-db.dts b/arch/arm64/boot/dts/marvell/armada-3720-db.dts index 9df0f06ce607..0a0e9e19e879 100644 --- a/arch/arm64/boot/dts/marvell/armada-3720-db.dts +++ b/arch/arm64/boot/dts/marvell/armada-3720-db.dts @@ -155,6 +155,9 @@ /* CON15(V2.0)/CON17(V1.4) : PCIe / CON15(V2.0)/CON12(V1.4) :mini-PCIe */ &pcie0 { + pinctrl-names = "default"; + pinctrl-0 = <&pcie_reset_pins &pcie_clkreq_pins>; + reset-gpios = <&gpiosb 3 GPIO_ACTIVE_LOW>; status = "okay"; }; diff --git a/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts b/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts index 13c0ec053ada..89c7385390f4 100644 --- a/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts +++ b/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts @@ -82,6 +82,9 @@ /* J9 */ &pcie0 { + pinctrl-names = "default"; + pinctrl-0 = <&pcie_reset_pins &pcie_clkreq_pins>; + reset-gpios = <&gpiosb 3 GPIO_ACTIVE_LOW>; status = "okay"; }; diff --git a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi index a4c81a1c77b7..b369356e7419 100644 --- a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi +++ b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi @@ -241,7 +241,7 @@ pcie_reset_pins: pcie-reset-pins { groups = "pcie1"; - function = "pcie"; + function = "gpio"; }; pcie_clkreq_pins: pcie-clkreq-pins {