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| author | Marek Behún <marek.behun@nic.cz> | 2021-11-25 00:05:00 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-01 09:27:41 +0100 |
| commit | c472f170cb1c833edf53493156ac6043ba80477e (patch) | |
| tree | 0c94e458d363d1c2ccb7853b78ade3f6901b0125 | |
| parent | 33a174313477c1d7e64b27829d9a82745ced75a7 (diff) | |
| download | linux-stable-c472f170cb1c833edf53493156ac6043ba80477e.tar.gz linux-stable-c472f170cb1c833edf53493156ac6043ba80477e.tar.bz2 linux-stable-c472f170cb1c833edf53493156ac6043ba80477e.zip | |
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 <marek.behun@nic.cz>
Cc: Remi Pommarel <repk@triplefau.lt>
Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm64/boot/dts/marvell/armada-3720-db.dts | 3 | ||||
| -rw-r--r-- | arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts | 3 | ||||
| -rw-r--r-- | arch/arm64/boot/dts/marvell/armada-37xx.dtsi | 2 |
3 files changed, 7 insertions, 1 deletions
diff --git a/arch/arm64/boot/dts/marvell/armada-3720-db.dts b/arch/arm64/boot/dts/marvell/armada-3720-db.dts index f2cc00594d64..3e5789f37206 100644 --- 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"; }; diff --git a/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts b/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts index 1a3e6e3b04eb..f36089198243 100644 --- a/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts +++ b/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts @@ -55,6 +55,9 @@ /* 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 5299a16459f2..7500be1a11a3 100644 --- a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi +++ b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi @@ -256,7 +256,7 @@ pcie_reset_pins: pcie-reset-pins { groups = "pcie1"; - function = "pcie"; + function = "gpio"; }; pcie_clkreq_pins: pcie-clkreq-pins { |