* [PATCH v2 0/2] NFC support for two Qualcomm SDM845 phones
@ 2026-03-23 23:20 David Heidelberg via B4 Relay
2026-03-23 23:20 ` [PATCH v2 1/2] arm64: dts: qcom: sdm845-oneplus: Enable NFC David Heidelberg via B4 Relay
2026-03-23 23:20 ` [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: " David Heidelberg via B4 Relay
0 siblings, 2 replies; 13+ messages in thread
From: David Heidelberg via B4 Relay @ 2026-03-23 23:20 UTC (permalink / raw)
To: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, oe-linux-nfc,
devicetree, linux-kernel, phone-devel, David Heidelberg
Verified with neard and
nfctool -d nfc0 -p
successfully detecting a tag.
Signed-off-by: David Heidelberg <david@ixit.cz>
---
Changes in v2:
- Use interrupts-extended. (Konrad)
- Dropped QUESTION prefix, as it's verified this settings work.
- Added compatible for OnePlus 6 based on schematics.
- Corrected axolotl NFC compatible based on information from Alexander (SHIFT).
- Link to v1: https://lore.kernel.org/r/20260322-oneplus-nfc-v1-0-5f22f544f0e2@ixit.cz
---
David Heidelberg (1):
arm64: dts: qcom: sdm845-shift-axolotl: Enable NFC
biemster (1):
arm64: dts: qcom: sdm845-oneplus: Enable NFC
.../arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi | 31 ++++++++++++++++++++
arch/arm64/boot/dts/qcom/sdm845-shift-axolotl.dts | 33 ++++++++++++++++++++++
2 files changed, 64 insertions(+)
---
base-commit: 09c0f7f1bcdbc3c37a5a760cbec76bf18f278406
change-id: 20251118-oneplus-nfc-c00ef1cdfa9b
Best regards,
--
David Heidelberg <david@ixit.cz>
^ permalink raw reply [flat|nested] 13+ messages in thread* [PATCH v2 1/2] arm64: dts: qcom: sdm845-oneplus: Enable NFC
2026-03-23 23:20 [PATCH v2 0/2] NFC support for two Qualcomm SDM845 phones David Heidelberg via B4 Relay
@ 2026-03-23 23:20 ` David Heidelberg via B4 Relay
2026-03-24 7:03 ` Krzysztof Kozlowski
2026-03-23 23:20 ` [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: " David Heidelberg via B4 Relay
1 sibling, 1 reply; 13+ messages in thread
From: David Heidelberg via B4 Relay @ 2026-03-23 23:20 UTC (permalink / raw)
To: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, oe-linux-nfc,
devicetree, linux-kernel, phone-devel, David Heidelberg
From: biemster <l.j.beemster@gmail.com>
Enable NFC controller NXP PN553, which is part of the package NXP NQ330
(NFC + eSE).
Signed-off-by: biemster <l.j.beemster@gmail.com>
Co-developed-by: David Heidelberg <david@ixit.cz>
Signed-off-by: David Heidelberg <david@ixit.cz>
---
.../arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi | 31 ++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
index 5b121ea5520f5..4fbce4233a773 100644
--- a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
+++ b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
@@ -392,6 +392,25 @@ &gpu_zap_shader {
firmware-name = "qcom/sdm845/OnePlus/enchilada/a630_zap.mbn";
};
+&i2c3 {
+ clock-frequency = <400000>;
+
+ status = "okay";
+
+ nfc@28 {
+ compatible = "nxp,pn553", "nxp,nxp-nci-i2c";
+ reg = <0x28>;
+
+ interrupts-extended = <&tlmm 63 IRQ_TYPE_EDGE_RISING>;
+
+ enable-gpios = <&tlmm 12 GPIO_ACTIVE_HIGH>;
+ firmware-gpios = <&tlmm 62 GPIO_ACTIVE_HIGH>;
+
+ pinctrl-0 = <&nfc_default>;
+ pinctrl-names = "default";
+ };
+};
+
&i2c10 {
status = "okay";
clock-frequency = <100000>;
@@ -594,6 +613,11 @@ &qupv3_id_0 {
status = "okay";
};
+&qup_i2c3_default {
+ drive-strength = <2>;
+ bias-disable;
+};
+
&qup_i2c10_default {
drive-strength = <2>;
bias-disable;
@@ -926,6 +950,13 @@ speaker_default: speaker-default-state {
bias-pull-up;
output-high;
};
+
+ nfc_default: nfc-default-state {
+ pins = "gpio12", "gpio62", "gpio63";
+ function = "gpio";
+ drive-strength = <6>;
+ bias-pull-up;
+ };
};
&venus {
--
2.53.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* Re: [PATCH v2 1/2] arm64: dts: qcom: sdm845-oneplus: Enable NFC
2026-03-23 23:20 ` [PATCH v2 1/2] arm64: dts: qcom: sdm845-oneplus: Enable NFC David Heidelberg via B4 Relay
@ 2026-03-24 7:03 ` Krzysztof Kozlowski
2026-03-24 9:35 ` David Heidelberg
0 siblings, 1 reply; 13+ messages in thread
From: Krzysztof Kozlowski @ 2026-03-24 7:03 UTC (permalink / raw)
To: david, Bjorn Andersson, Konrad Dybcio, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, oe-linux-nfc,
devicetree, linux-kernel, phone-devel
On 24/03/2026 00:20, David Heidelberg via B4 Relay wrote:
> From: biemster <l.j.beemster@gmail.com>
>
> Enable NFC controller NXP PN553, which is part of the package NXP NQ330
> (NFC + eSE).
>
> Signed-off-by: biemster <l.j.beemster@gmail.com>
Same comment as last time. We do not take anonymous contributions.
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 1/2] arm64: dts: qcom: sdm845-oneplus: Enable NFC
2026-03-24 7:03 ` Krzysztof Kozlowski
@ 2026-03-24 9:35 ` David Heidelberg
2026-03-24 9:38 ` Krzysztof Kozlowski
0 siblings, 1 reply; 13+ messages in thread
From: David Heidelberg @ 2026-03-24 9:35 UTC (permalink / raw)
To: Krzysztof Kozlowski, Bjorn Andersson, Konrad Dybcio, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, oe-linux-nfc,
devicetree, linux-kernel, phone-devel
On 24/03/2026 08:03, Krzysztof Kozlowski wrote:
> On 24/03/2026 00:20, David Heidelberg via B4 Relay wrote:
>> From: biemster <l.j.beemster@gmail.com>
>>
>> Enable NFC controller NXP PN553, which is part of the package NXP NQ330
>> (NFC + eSE).
>>
>> Signed-off-by: biemster <l.j.beemster@gmail.com>
>
> Same comment as last time. We do not take anonymous contributions.
> then you just add a line saying:
>
> Signed-off-by: Random J Developer <random@developer.example.org>
>
> using a known identity (sorry, no anonymous contributions.)
Quoting the kernel documentation, biemster is known contributor to us (hanging
in sdm845-next chat room, I'm personally aware of his presence for more than ~ 2
years).
I could switch Author / Co-developed-by with me in this case, but since biemster
did the initial work, it feels right to keep the credit.
David
>
> Best regards,
> Krzysztof
--
David Heidelberg
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 1/2] arm64: dts: qcom: sdm845-oneplus: Enable NFC
2026-03-24 9:35 ` David Heidelberg
@ 2026-03-24 9:38 ` Krzysztof Kozlowski
0 siblings, 0 replies; 13+ messages in thread
From: Krzysztof Kozlowski @ 2026-03-24 9:38 UTC (permalink / raw)
To: David Heidelberg, Bjorn Andersson, Konrad Dybcio, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, oe-linux-nfc,
devicetree, linux-kernel, phone-devel
On 24/03/2026 10:35, David Heidelberg wrote:
> On 24/03/2026 08:03, Krzysztof Kozlowski wrote:
>> On 24/03/2026 00:20, David Heidelberg via B4 Relay wrote:
>>> From: biemster <l.j.beemster@gmail.com>
>>>
>>> Enable NFC controller NXP PN553, which is part of the package NXP NQ330
>>> (NFC + eSE).
>>>
>>> Signed-off-by: biemster <l.j.beemster@gmail.com>
>>
>> Same comment as last time. We do not take anonymous contributions.
>
> > then you just add a line saying:
> >
> > Signed-off-by: Random J Developer <random@developer.example.org>
> >
> > using a known identity (sorry, no anonymous contributions.)
>
> Quoting the kernel documentation, biemster is known contributor to us (hanging
> in sdm845-next chat room, I'm personally aware of his presence for more than ~ 2
> years).
>
> I could switch Author / Co-developed-by with me in this case, but since biemster
> did the initial work, it feels right to keep the credit.
Hanging in chat room is not a definition of a known contributor.
Absolutely anyone can be behind a nickname on IRC channel. Or Github repo.
The kernel docs is not asking for known contributors. We ask for *known
identity*.
Quoting:
"sorry, no anonymous contributions."
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: Enable NFC
2026-03-23 23:20 [PATCH v2 0/2] NFC support for two Qualcomm SDM845 phones David Heidelberg via B4 Relay
2026-03-23 23:20 ` [PATCH v2 1/2] arm64: dts: qcom: sdm845-oneplus: Enable NFC David Heidelberg via B4 Relay
@ 2026-03-23 23:20 ` David Heidelberg via B4 Relay
2026-03-24 13:12 ` Konrad Dybcio
1 sibling, 1 reply; 13+ messages in thread
From: David Heidelberg via B4 Relay @ 2026-03-23 23:20 UTC (permalink / raw)
To: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, oe-linux-nfc,
devicetree, linux-kernel, phone-devel, David Heidelberg
From: David Heidelberg <david@ixit.cz>
Definition of the NFC.
Signed-off-by: David Heidelberg <david@ixit.cz>
---
arch/arm64/boot/dts/qcom/sdm845-shift-axolotl.dts | 33 +++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/arch/arm64/boot/dts/qcom/sdm845-shift-axolotl.dts b/arch/arm64/boot/dts/qcom/sdm845-shift-axolotl.dts
index 51b041f91d3e2..eea63aa170b16 100644
--- a/arch/arm64/boot/dts/qcom/sdm845-shift-axolotl.dts
+++ b/arch/arm64/boot/dts/qcom/sdm845-shift-axolotl.dts
@@ -431,6 +431,25 @@ &gpu_zap_shader {
firmware-name = "qcom/sdm845/SHIFT/axolotl/a630_zap.mbn";
};
+&i2c3 {
+ clock-frequency = <400000>;
+
+ status = "okay";
+
+ nfc@28 {
+ compatible = "nxp,pn553", "nxp,nxp-nci-i2c";
+ reg = <0x28>;
+
+ interrupts-extended = <&tlmm 63 IRQ_TYPE_EDGE_RISING>;
+
+ enable-gpios = <&tlmm 12 GPIO_ACTIVE_HIGH>;
+ firmware-gpios = <&tlmm 62 GPIO_ACTIVE_HIGH>;
+
+ pinctrl-0 = <&nfc_int_default &nfc_enable_default>;
+ pinctrl-names = "default";
+ };
+};
+
&i2c5 {
status = "okay";
@@ -609,6 +628,20 @@ &slpi_pas {
&tlmm {
gpio-reserved-ranges = <0 4>, <81 4>;
+ nfc_int_default: nfc-int-default-state {
+ pins = "gpio63";
+ function = "gpio";
+ drive-strength = <2>;
+ bias-pull-up;
+ };
+
+ nfc_enable_default: nfc-enable-default-state {
+ pins = "gpio12", "gpio62";
+ function = "gpio";
+ drive-strength = <2>;
+ bias-pull-up;
+ };
+
sde_dsi_active: sde-dsi-active-state {
pins = "gpio6", "gpio11";
function = "gpio";
--
2.53.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* Re: [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: Enable NFC
2026-03-23 23:20 ` [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: " David Heidelberg via B4 Relay
@ 2026-03-24 13:12 ` Konrad Dybcio
2026-03-24 18:08 ` David Heidelberg
0 siblings, 1 reply; 13+ messages in thread
From: Konrad Dybcio @ 2026-03-24 13:12 UTC (permalink / raw)
To: david, Bjorn Andersson, Konrad Dybcio, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, oe-linux-nfc,
devicetree, linux-kernel, phone-devel
On 3/24/26 12:20 AM, David Heidelberg via B4 Relay wrote:
> From: David Heidelberg <david@ixit.cz>
>
> Definition of the NFC.
"meh" commit message
[...]
> + nfc_enable_default: nfc-enable-default-state {
> + pins = "gpio12", "gpio62";
> + function = "gpio";
> + drive-strength = <2>;
> + bias-pull-up;
Are you sure about pulling up an active-high pin?
FWIW TLMM subnodes are best sorted by pin index (although the file
currently doesn't really do that) as per dts coding style
Konrad
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: Enable NFC
2026-03-24 13:12 ` Konrad Dybcio
@ 2026-03-24 18:08 ` David Heidelberg
2026-03-25 11:20 ` Konrad Dybcio
0 siblings, 1 reply; 13+ messages in thread
From: David Heidelberg @ 2026-03-24 18:08 UTC (permalink / raw)
To: Konrad Dybcio, Konrad Dybcio, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, Rob Herring,
oe-linux-nfc, Krzysztof Kozlowski, devicetree, Conor Dooley,
linux-kernel, phone-devel, Bjorn Andersson
On 24/03/2026 14:12, Konrad Dybcio wrote:
> On 3/24/26 12:20 AM, David Heidelberg via B4 Relay wrote:
>> From: David Heidelberg <david@ixit.cz>
>>
>> Definition of the NFC.
>
> "meh" commit message
>
> [...]
>
>> + nfc_enable_default: nfc-enable-default-state {
>> + pins = "gpio12", "gpio62";
>> + function = "gpio";
>> + drive-strength = <2>;
>> + bias-pull-up;
>
> Are you sure about pulling up an active-high pin?
I'm not sure, but downstream does it (and "works for me"). Maybe Alexander would
know more details here.
David
>
> FWIW TLMM subnodes are best sorted by pin index (although the file
> currently doesn't really do that) as per dts coding style
I assume when I group the -pins into -state it doesn't apply anymore? As I don't
feel having pins relevant to one device / subsystem all over the place is extra
clean.
David
P.S. before v3 code is here
https://codeberg.org/sdm845/linux/commits/branch/b4/oneplus-nfc
>
> Konrad
--
David Heidelberg
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: Enable NFC
2026-03-24 18:08 ` David Heidelberg
@ 2026-03-25 11:20 ` Konrad Dybcio
2026-03-25 11:31 ` Krzysztof Kozlowski
2026-03-25 20:17 ` David Heidelberg
0 siblings, 2 replies; 13+ messages in thread
From: Konrad Dybcio @ 2026-03-25 11:20 UTC (permalink / raw)
To: David Heidelberg, Konrad Dybcio, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, Rob Herring,
oe-linux-nfc, Krzysztof Kozlowski, devicetree, Conor Dooley,
linux-kernel, phone-devel, Bjorn Andersson
On 3/24/26 7:08 PM, David Heidelberg wrote:
>
>
> On 24/03/2026 14:12, Konrad Dybcio wrote:
>> On 3/24/26 12:20 AM, David Heidelberg via B4 Relay wrote:
>>> From: David Heidelberg <david@ixit.cz>
>>>
>>> Definition of the NFC.
>>
>> "meh" commit message
>>
>> [...]
>>
>>> + nfc_enable_default: nfc-enable-default-state {
>>> + pins = "gpio12", "gpio62";
>>> + function = "gpio";
>>> + drive-strength = <2>;
>>> + bias-pull-up;
>>
>> Are you sure about pulling up an active-high pin?
>
> I'm not sure, but downstream does it (and "works for me"). Maybe Alexander would know more details here.
Would changing it to bias-disable also "work for you"?
>
> David
>
>>
>> FWIW TLMM subnodes are best sorted by pin index (although the file
>> currently doesn't really do that) as per dts coding style
>
> I assume when I group the -pins into -state it doesn't apply anymore? As I don't feel having pins relevant to one device / subsystem all over the place is extra clean.
Krzysztof?
Konrad
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: Enable NFC
2026-03-25 11:20 ` Konrad Dybcio
@ 2026-03-25 11:31 ` Krzysztof Kozlowski
2026-03-25 11:39 ` Konrad Dybcio
2026-03-25 20:17 ` David Heidelberg
1 sibling, 1 reply; 13+ messages in thread
From: Krzysztof Kozlowski @ 2026-03-25 11:31 UTC (permalink / raw)
To: Konrad Dybcio, David Heidelberg, Konrad Dybcio, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, Rob Herring,
oe-linux-nfc, Krzysztof Kozlowski, devicetree, Conor Dooley,
linux-kernel, phone-devel, Bjorn Andersson
On 25/03/2026 12:20, Konrad Dybcio wrote:
>>
>>>
>>> FWIW TLMM subnodes are best sorted by pin index (although the file
>>> currently doesn't really do that) as per dts coding style
>>
>> I assume when I group the -pins into -state it doesn't apply anymore? As I don't feel having pins relevant to one device / subsystem all over the place is extra clean.
>
nfc_int_default: nfc-int-default-state {
pins = "gpio63";
};
nfc_enable_default: nfc-enable-default-state {
pins = "gpio12", "gpio62";
};
sde_dsi_active: sde-dsi-active-state {
pins = "gpio6", "gpio11";
}
Let's imagine future possible implementation of DTS coding style
linter/checkpatch. How it would sort the nodes? Either by node name or
the first value in "pins", this this would be:
sde_dsi_active: sde-dsi-active-state {
pins = "gpio6", "gpio11";
}
nfc_enable_default: nfc-enable-default-state {
pins = "gpio12", "gpio62";
};
nfc_int_default: nfc-int-default-state {
pins = "gpio63";
};
So that's how you code. Less work for future linter/checkpatch.
The trouble is that "pins" property sorting can result in nodes being
spread all over, imagine:
nfc_enable_default: nfc-enable-default-state {
pins = "gpio5", "gpio62";
// ^^^^^ DIFFERENCE!
};
sde_dsi_active: sde-dsi-active-state {
pins = "gpio6", "gpio11";
}
nfc_int_default: nfc-int-default-state {
pins = "gpio63";
};
That's why I would propose to keep everything sorted by node name, but I
am fine with both choices. Qualcomm maintainers decide about such
detailed style they want to impose.
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: Enable NFC
2026-03-25 11:31 ` Krzysztof Kozlowski
@ 2026-03-25 11:39 ` Konrad Dybcio
0 siblings, 0 replies; 13+ messages in thread
From: Konrad Dybcio @ 2026-03-25 11:39 UTC (permalink / raw)
To: Krzysztof Kozlowski, David Heidelberg, Konrad Dybcio,
Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, Rob Herring,
oe-linux-nfc, Krzysztof Kozlowski, devicetree, Conor Dooley,
linux-kernel, phone-devel, Bjorn Andersson
On 3/25/26 12:31 PM, Krzysztof Kozlowski wrote:
> On 25/03/2026 12:20, Konrad Dybcio wrote:
>>>
>>>>
>>>> FWIW TLMM subnodes are best sorted by pin index (although the file
>>>> currently doesn't really do that) as per dts coding style
>>>
>>> I assume when I group the -pins into -state it doesn't apply anymore? As I don't feel having pins relevant to one device / subsystem all over the place is extra clean.
>>
>
> nfc_int_default: nfc-int-default-state {
> pins = "gpio63";
> };
>
> nfc_enable_default: nfc-enable-default-state {
> pins = "gpio12", "gpio62";
> };
>
> sde_dsi_active: sde-dsi-active-state {
> pins = "gpio6", "gpio11";
> }
>
> Let's imagine future possible implementation of DTS coding style
> linter/checkpatch. How it would sort the nodes? Either by node name or
> the first value in "pins", this this would be:
>
> sde_dsi_active: sde-dsi-active-state {
> pins = "gpio6", "gpio11";
> }
>
> nfc_enable_default: nfc-enable-default-state {
> pins = "gpio12", "gpio62";
> };
>
> nfc_int_default: nfc-int-default-state {
> pins = "gpio63";
> };
>
> So that's how you code. Less work for future linter/checkpatch.
>
> The trouble is that "pins" property sorting can result in nodes being
> spread all over, imagine:
>
> nfc_enable_default: nfc-enable-default-state {
> pins = "gpio5", "gpio62";
> // ^^^^^ DIFFERENCE!
> };
>
> sde_dsi_active: sde-dsi-active-state {
> pins = "gpio6", "gpio11";
> }
>
> nfc_int_default: nfc-int-default-state {
> pins = "gpio63";
> };
>
> That's why I would propose to keep everything sorted by node name, but I
> am fine with both choices. Qualcomm maintainers decide about such
> detailed style they want to impose.
At LPC we agreed that the last sentence should not be the case ;)
I think I'm fine with "children by name" then..
Konrad
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: Enable NFC
2026-03-25 11:20 ` Konrad Dybcio
2026-03-25 11:31 ` Krzysztof Kozlowski
@ 2026-03-25 20:17 ` David Heidelberg
2026-03-26 11:39 ` Konrad Dybcio
1 sibling, 1 reply; 13+ messages in thread
From: David Heidelberg @ 2026-03-25 20:17 UTC (permalink / raw)
To: Konrad Dybcio, Konrad Dybcio, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, Rob Herring,
oe-linux-nfc, Krzysztof Kozlowski, devicetree, Conor Dooley,
linux-kernel, phone-devel, Bjorn Andersson
On 25/03/2026 12:20, Konrad Dybcio wrote:
> On 3/24/26 7:08 PM, David Heidelberg wrote:
>>
>>
>> On 24/03/2026 14:12, Konrad Dybcio wrote:
>>> On 3/24/26 12:20 AM, David Heidelberg via B4 Relay wrote:
>>>> From: David Heidelberg <david@ixit.cz>
>>>>
>>>> Definition of the NFC.
>>>
>>> "meh" commit message
>>>
>>> [...]
>>>
>>>> + nfc_enable_default: nfc-enable-default-state {
>>>> + pins = "gpio12", "gpio62";
>>>> + function = "gpio";
>>>> + drive-strength = <2>;
>>>> + bias-pull-up;
bias-disable;
>>>
>>> Are you sure about pulling up an active-high pin?
>>
>> I'm not sure, but downstream does it (and "works for me"). Maybe Alexander would know more details here.
>
> Would changing it to bias-disable also "work for you"?
Yeah, works for me. Should OnePlus 6 do the same?
Looking at OP6 datasheet, there is no pull-up/down on 12,62,nor IRQ 63.
David
>
>>
>> David
>>
>>>
>>> FWIW TLMM subnodes are best sorted by pin index (although the file
>>> currently doesn't really do that) as per dts coding style
>>
>> I assume when I group the -pins into -state it doesn't apply anymore? As I don't feel having pins relevant to one device / subsystem all over the place is extra clean.
>
> Krzysztof?
>
> Konrad
--
David Heidelberg
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: Enable NFC
2026-03-25 20:17 ` David Heidelberg
@ 2026-03-26 11:39 ` Konrad Dybcio
0 siblings, 0 replies; 13+ messages in thread
From: Konrad Dybcio @ 2026-03-26 11:39 UTC (permalink / raw)
To: David Heidelberg, Konrad Dybcio, Alexander Martinz
Cc: Petr Hodina, biemster, netdev, linux-arm-msm, Rob Herring,
oe-linux-nfc, Krzysztof Kozlowski, devicetree, Conor Dooley,
linux-kernel, phone-devel, Bjorn Andersson
On 3/25/26 9:17 PM, David Heidelberg wrote:
> On 25/03/2026 12:20, Konrad Dybcio wrote:
>> On 3/24/26 7:08 PM, David Heidelberg wrote:
>>>
>>>
>>> On 24/03/2026 14:12, Konrad Dybcio wrote:
>>>> On 3/24/26 12:20 AM, David Heidelberg via B4 Relay wrote:
>>>>> From: David Heidelberg <david@ixit.cz>
>>>>>
>>>>> Definition of the NFC.
>>>>
>>>> "meh" commit message
>>>>
>>>> [...]
>>>>
>>>>> + nfc_enable_default: nfc-enable-default-state {
>>>>> + pins = "gpio12", "gpio62";
>>>>> + function = "gpio";
>>>>> + drive-strength = <2>;
>>>>> + bias-pull-up;
>
> bias-disable;
>>>>
>>>> Are you sure about pulling up an active-high pin?
>>>
>>> I'm not sure, but downstream does it (and "works for me"). Maybe Alexander would know more details here.
>>
>> Would changing it to bias-disable also "work for you"?
>
> Yeah, works for me. Should OnePlus 6 do the same?
>
> Looking at OP6 datasheet, there is no pull-up/down on 12,62,nor IRQ 63.
Generally the internal bias would be used to counteract random noise posing
as signal, to ensure the line is kept in the "inactive" state when not
actively driven
I can see that the driver initially requests both to LOW and then sets it to
high based on the desired mode in nxp_nci_i2c_set_mode(), so pulling up is
perhaps never really desired.
Konrad
^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2026-03-26 11:39 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-03-23 23:20 [PATCH v2 0/2] NFC support for two Qualcomm SDM845 phones David Heidelberg via B4 Relay
2026-03-23 23:20 ` [PATCH v2 1/2] arm64: dts: qcom: sdm845-oneplus: Enable NFC David Heidelberg via B4 Relay
2026-03-24 7:03 ` Krzysztof Kozlowski
2026-03-24 9:35 ` David Heidelberg
2026-03-24 9:38 ` Krzysztof Kozlowski
2026-03-23 23:20 ` [PATCH v2 2/2] arm64: dts: qcom: sdm845-shift-axolotl: " David Heidelberg via B4 Relay
2026-03-24 13:12 ` Konrad Dybcio
2026-03-24 18:08 ` David Heidelberg
2026-03-25 11:20 ` Konrad Dybcio
2026-03-25 11:31 ` Krzysztof Kozlowski
2026-03-25 11:39 ` Konrad Dybcio
2026-03-25 20:17 ` David Heidelberg
2026-03-26 11:39 ` Konrad Dybcio
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