From 715878016984b2617f6c1f177c50039e12e7bd5b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marek=20Beh=C3=BAn?= Date: Thu, 30 Apr 2020 10:06:23 +0200 Subject: [PATCH] arm64: dts: marvell: armada-37xx: Set pcie_reset_pin to gpio function MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 --- arch/arm64/boot/dts/marvell/armada-3720-db.dts | 3 +++ arch/arm64/boot/dts/marvell/armada-3720-espressobin.dtsi | 1 + arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts | 4 ---- arch/arm64/boot/dts/marvell/armada-37xx.dtsi | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-) --- a/arch/arm64/boot/dts/marvell/armada-3720-db.dts +++ b/arch/arm64/boot/dts/marvell/armada-3720-db.dts @@ -128,6 +128,9 @@ /* 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"; }; --- a/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts +++ b/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts @@ -59,6 +59,7 @@ phys = <&comphy1 0>; pinctrl-names = "default"; pinctrl-0 = <&pcie_reset_pins &pcie_clkreq_pins>; + reset-gpios = <&gpiosb 3 GPIO_ACTIVE_LOW>; }; /* J6 */ --- a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts +++ b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts @@ -127,10 +127,6 @@ }; }; -&pcie_reset_pins { - function = "gpio"; -}; - &pcie0 { pinctrl-names = "default"; pinctrl-0 = <&pcie_reset_pins &pcie_clkreq_pins>; --- a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi +++ b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi @@ -318,7 +318,7 @@ pcie_reset_pins: pcie-reset-pins { groups = "pcie1"; - function = "pcie"; + function = "gpio"; }; pcie_clkreq_pins: pcie-clkreq-pins {