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author | Marek BehĂșn <marek.behun@nic.cz> | 2020-04-30 10:06:23 +0200 |
---|---|---|
committer | Gregory CLEMENT <gregory.clement@bootlin.com> | 2020-05-17 17:51:43 +0200 |
commit | 715878016984b2617f6c1f177c50039e12e7bd5b (patch) | |
tree | e34d06027113bab0384ae0c25377064eb5eaef9d /arch/arm64/boot/dts/marvell | |
parent | 847c3323d5d1d2c7c61a1257dbec6f0d975e2b61 (diff) | |
download | linux-715878016984b2617f6c1f177c50039e12e7bd5b.tar.bz2 |
arm64: dts: marvell: armada-37xx: Set pcie_reset_pin to gpio function
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 BehĂșn <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>
Diffstat (limited to 'arch/arm64/boot/dts/marvell')
4 files changed, 5 insertions, 5 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.dtsi b/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dtsi index 42e992f9c8a5..c92ad664cb0e 100644 --- a/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dtsi +++ b/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dtsi @@ -47,6 +47,7 @@ phys = <&comphy1 0>; pinctrl-names = "default"; pinctrl-0 = <&pcie_reset_pins &pcie_clkreq_pins>; + reset-gpios = <&gpiosb 3 GPIO_ACTIVE_LOW>; }; /* J6 */ diff --git a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts index bb42d1e6a4e9..e496bd9d4737 100644 --- a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts +++ b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts @@ -128,10 +128,6 @@ }; }; -&pcie_reset_pins { - function = "gpio"; -}; - &pcie0 { pinctrl-names = "default"; pinctrl-0 = <&pcie_reset_pins &pcie_clkreq_pins>; diff --git a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi index 000c135e39b7..7909c146eabf 100644 --- a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi +++ b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi @@ -317,7 +317,7 @@ pcie_reset_pins: pcie-reset-pins { groups = "pcie1"; - function = "pcie"; + function = "gpio"; }; pcie_clkreq_pins: pcie-clkreq-pins { |