This is a note to let you know that I've just added the patch titled
arm64: dts: marvell: armada-37xx: Set pcie_reset_pin to gpio function
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-dts-marvell-armada-37xx-set-pcie_reset_pin-to-gpio-function.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Nov 29 01:32:04 PM CET 2021
From: "Marek Behún" <kabel@xxxxxxxxxx>
Date: Wed, 24 Nov 2021 23:49:33 +0100
Subject: arm64: dts: marvell: armada-37xx: Set pcie_reset_pin to gpio function
To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>, Sasha Levin <sashal@xxxxxxxxxx>
Cc: pali@xxxxxxxxxx, stable@xxxxxxxxxxxxxxx, "Marek Behún" <marek.behun@xxxxxx>, "Remi Pommarel" <repk@xxxxxxxxxxxx>, "Tomasz Maciej Nowak" <tmn505@xxxxxxxxx>, "Thomas Petazzoni" <thomas.petazzoni@xxxxxxxxxxx>, "Gregory CLEMENT" <gregory.clement@xxxxxxxxxxx>, "Marek Behún" <kabel@xxxxxxxxxx>
Message-ID: <20211124224933.24275-25-kabel@xxxxxxxxxx>
From: Marek Behún <marek.behun@xxxxxx>
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 <marek.behun@xxxxxx>
Cc: Remi Pommarel <repk@xxxxxxxxxxxx>
Tested-by: Tomasz Maciej Nowak <tmn505@xxxxxxxxx>
Acked-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxx>
Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>
Signed-off-by: Marek Behún <kabel@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/boot/dts/marvell/armada-3720-db.dts | 3 +++
arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts | 3 +++
arch/arm64/boot/dts/marvell/armada-37xx.dtsi | 2 +-
3 files changed, 7 insertions(+), 1 deletion(-)
--- 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";
};
--- 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";
};
--- 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 {
Patches currently in stable-queue which might be from kabel@xxxxxxxxxx are
queue-4.14/pci-aardvark-move-pcie-reset-card-code-to-advk_pcie_train_link.patch
queue-4.14/pci-aardvark-introduce-an-advk_pcie_valid_device-helper.patch
queue-4.14/pci-aardvark-update-comment-about-disabling-link-training.patch
queue-4.14/pci-aardvark-train-link-immediately-after-enabling-training.patch
queue-4.14/arm64-dts-marvell-armada-37xx-declare-pcie-reset-pin.patch
queue-4.14/pci-aardvark-replace-custom-macros-by-standard-linux-pci_regs.h-macros.patch
queue-4.14/pci-aardvark-fix-a-leaked-reference-by-adding-missing-of_node_put.patch
queue-4.14/pci-aardvark-fix-pcie-max-payload-size-setting.patch
queue-4.14/pinctrl-armada-37xx-correct-pwm-pins-definitions.patch
queue-4.14/arm64-dts-marvell-armada-37xx-set-pcie_reset_pin-to-gpio-function.patch
queue-4.14/pci-aardvark-configure-pcie-resources-from-ranges-dt-property.patch
queue-4.14/pci-aardvark-improve-link-training.patch
queue-4.14/pci-aardvark-fix-link-training.patch
queue-4.14/pci-aardvark-fix-checking-for-link-up-via-ltssm-state.patch
queue-4.14/pci-aardvark-issue-perst-via-gpio.patch
queue-4.14/pinctrl-armada-37xx-correct-mpp-definitions.patch
queue-4.14/pci-add-pci_exp_lnkctl2_tls-macros.patch
queue-4.14/pci-aardvark-wait-for-endpoint-to-be-ready-before-training-link.patch
queue-4.14/pinctrl-armada-37xx-add-missing-pin-pcie1-wakeup.patch
queue-4.14/pci-aardvark-fix-compilation-on-s390.patch
queue-4.14/pci-aardvark-fix-i-o-space-page-leak.patch
queue-4.14/pci-aardvark-don-t-touch-pcie-registers-if-no-card-connected.patch
queue-4.14/pci-aardvark-remove-pcie-outbound-window-configuration.patch
queue-4.14/pci-aardvark-indicate-error-in-val-when-config-read-fails.patch
