| Message ID | 20220930182212.209804-2-krzysztof.kozlowski@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/3] arm64: dts: qcom: sdm630: fix UART1 pin bias | expand |
On 30/09/2022 22:12, Doug Anderson wrote: > Hi, > > On Fri, Sep 30, 2022 at 11:22 AM Krzysztof Kozlowski > <krzysztof.kozlowski@linaro.org> wrote: >> >> The pin configuration (done with generic pin controller helpers and >> as expressed by bindings) requires children nodes with either: >> 1. "pins" property and the actual configuration, >> 2. another set of nodes with above point. >> >> The qup_spi2_default pin configuration used second method - with a >> "pinmux" child. >> >> Fixes: 8d23a0040475 ("arm64: dts: qcom: db845c: add Low speed expansion i2c and spi nodes") >> Cc: <stable@vger.kernel.org> >> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> >> >> --- >> >> Not tested on hardware. >> --- >> arch/arm64/boot/dts/qcom/sdm845-db845c.dts | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts >> index 132417e2d11e..a157eab66dee 100644 >> --- a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts >> +++ b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts >> @@ -1123,7 +1123,9 @@ &wifi { >> >> /* PINCTRL - additions to nodes defined in sdm845.dtsi */ >> &qup_spi2_default { >> - drive-strength = <16>; >> + pinmux { >> + drive-strength = <16>; >> + }; > > The convention on Qualcomm boards of this era is that muxing (setting > the function) is done under a "pinmux" node and, unless some of the > pins need to be treated differently like for the UARTs, configuration > (bias, drive strength, etc) is done under a "pinconf" subnode. Yes, although this was not expressed in bindings. > I > believe that the "pinconf" subnode also needs to replicate the list of > pins, or at least that's what we did everywhere else on sdm845 / > sc7180. Yes. > > Thus to match conventions, I assume you'd do: > > &qup_spi2_default { > pinconf { No, because I want a convention of all pinctrl bindings and drivers, not convention of old pinctrl ones. The new ones are already moved or being moved to "-state" and "-pins". In the same time I am also unifying the requirement of "function" property - enforcing it in each node, thus "pinconf" will not be valid anymore. > pins = "gpio27", "gpio28", "gpio29", "gpio30"; > drive-strength = <16>; > }; > }; > > We've since moved away from this to a less cumbersome approach, but > for "older" boards like db845c we should probably match the existing > convention, or have a flag day and change all sdm845 boards over to > the new convention. That's what my next patchset from yesterday was doing. Unifying the bindings with modern bindings and converting DTS to match them. https://lore.kernel.org/linux-devicetree/20220930200529.331223-1-krzysztof.kozlowski@linaro.org/T/#t Best regards, Krzysztof
Hi, On Sat, Oct 1, 2022 at 3:01 AM Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote: > > On 30/09/2022 22:12, Doug Anderson wrote: > > Hi, > > > > On Fri, Sep 30, 2022 at 11:22 AM Krzysztof Kozlowski > > <krzysztof.kozlowski@linaro.org> wrote: > >> > >> The pin configuration (done with generic pin controller helpers and > >> as expressed by bindings) requires children nodes with either: > >> 1. "pins" property and the actual configuration, > >> 2. another set of nodes with above point. > >> > >> The qup_spi2_default pin configuration used second method - with a > >> "pinmux" child. > >> > >> Fixes: 8d23a0040475 ("arm64: dts: qcom: db845c: add Low speed expansion i2c and spi nodes") > >> Cc: <stable@vger.kernel.org> > >> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> > >> > >> --- > >> > >> Not tested on hardware. > >> --- > >> arch/arm64/boot/dts/qcom/sdm845-db845c.dts | 4 +++- > >> 1 file changed, 3 insertions(+), 1 deletion(-) > >> > >> diff --git a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts > >> index 132417e2d11e..a157eab66dee 100644 > >> --- a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts > >> +++ b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts > >> @@ -1123,7 +1123,9 @@ &wifi { > >> > >> /* PINCTRL - additions to nodes defined in sdm845.dtsi */ > >> &qup_spi2_default { > >> - drive-strength = <16>; > >> + pinmux { > >> + drive-strength = <16>; > >> + }; > > > > The convention on Qualcomm boards of this era is that muxing (setting > > the function) is done under a "pinmux" node and, unless some of the > > pins need to be treated differently like for the UARTs, configuration > > (bias, drive strength, etc) is done under a "pinconf" subnode. > > Yes, although this was not expressed in bindings. > > > I > > believe that the "pinconf" subnode also needs to replicate the list of > > pins, or at least that's what we did everywhere else on sdm845 / > > sc7180. > > Yes. > > > > > Thus to match conventions, I assume you'd do: > > > > &qup_spi2_default { > > pinconf { > > No, because I want a convention of all pinctrl bindings and drivers, not > convention of old pinctrl ones. The new ones are already moved or being > moved to "-state" and "-pins". In the same time I am also unifying the > requirement of "function" property - enforcing it in each node, thus > "pinconf" will not be valid anymore. Regardless of where we want to end up, it feels like as of ${SUBJECT} patch this should match existing conventions in this file. If a later patch wants to change the conventions in this file then it can, but having just this one patch leaving things in an inconsistent state isn't great IMO... If this really has to be one-off then the subnode shouldn't be called "pinmux". A subnode called "pinmux" implies that it just has muxing information in it. After your patch this is called "pinmux" but has _configuration_ in it. > > pins = "gpio27", "gpio28", "gpio29", "gpio30"; > > drive-strength = <16>; > > }; > > }; > > > > We've since moved away from this to a less cumbersome approach, but > > for "older" boards like db845c we should probably match the existing > > convention, or have a flag day and change all sdm845 boards over to > > the new convention. > > That's what my next patchset from yesterday was doing. Unifying the > bindings with modern bindings and converting DTS to match them. > > https://lore.kernel.org/linux-devicetree/20220930200529.331223-1-krzysztof.kozlowski@linaro.org/T/#t I wasn't CCed on that patch series. A few things jump out as not quite right to me. I'll try to do a review. -Doug
On 03/10/2022 17:40, Doug Anderson wrote: >>>> >>>> diff --git a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts >>>> index 132417e2d11e..a157eab66dee 100644 >>>> --- a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts >>>> +++ b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts >>>> @@ -1123,7 +1123,9 @@ &wifi { >>>> >>>> /* PINCTRL - additions to nodes defined in sdm845.dtsi */ >>>> &qup_spi2_default { >>>> - drive-strength = <16>; >>>> + pinmux { >>>> + drive-strength = <16>; >>>> + }; >>> >>> The convention on Qualcomm boards of this era is that muxing (setting >>> the function) is done under a "pinmux" node and, unless some of the >>> pins need to be treated differently like for the UARTs, configuration >>> (bias, drive strength, etc) is done under a "pinconf" subnode. >> >> Yes, although this was not expressed in bindings. >> >>> I >>> believe that the "pinconf" subnode also needs to replicate the list of >>> pins, or at least that's what we did everywhere else on sdm845 / >>> sc7180. >> >> Yes. >> >>> >>> Thus to match conventions, I assume you'd do: >>> >>> &qup_spi2_default { >>> pinconf { >> >> No, because I want a convention of all pinctrl bindings and drivers, not >> convention of old pinctrl ones. The new ones are already moved or being >> moved to "-state" and "-pins". In the same time I am also unifying the >> requirement of "function" property - enforcing it in each node, thus >> "pinconf" will not be valid anymore. > > Regardless of where we want to end up, it feels like as of ${SUBJECT} > patch this should match existing conventions in this file. If a later > patch wants to change the conventions in this file then it can, but > having just this one patch leaving things in an inconsistent state > isn't great IMO... > > If this really has to be one-off then the subnode shouldn't be called > "pinmux". A subnode called "pinmux" implies that it just has muxing > information in it. After your patch this is called "pinmux" but has > _configuration_ in it. > It is a poor argument to keep some convention which is both undocumented, not kept in this file and known only to some folks (although that's effect of lack of documentation). Even the bindings do not say it should be "pinconf" but they mention "config" in example. The existing sdm845.dts uses config - so why now there should be "pinconf"? By this "convention" we have both "pinmux" and "mux", perfect. Several other pins do not have pinmux/mux/config at all. This convention was never implemented, so there is nothing to keep/match. Changing it to "config" (because this is the most used "convention" in the file and bindings) would also mean to add useless "pins" which will be in next patch removed. Best regards, Krzysztof
Hi, On Mon, Oct 3, 2022 at 10:57 AM Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote: > > On 03/10/2022 17:40, Doug Anderson wrote: > >>>> > >>>> diff --git a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts > >>>> index 132417e2d11e..a157eab66dee 100644 > >>>> --- a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts > >>>> +++ b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts > >>>> @@ -1123,7 +1123,9 @@ &wifi { > >>>> > >>>> /* PINCTRL - additions to nodes defined in sdm845.dtsi */ > >>>> &qup_spi2_default { > >>>> - drive-strength = <16>; > >>>> + pinmux { > >>>> + drive-strength = <16>; > >>>> + }; > >>> > >>> The convention on Qualcomm boards of this era is that muxing (setting > >>> the function) is done under a "pinmux" node and, unless some of the > >>> pins need to be treated differently like for the UARTs, configuration > >>> (bias, drive strength, etc) is done under a "pinconf" subnode. > >> > >> Yes, although this was not expressed in bindings. > >> > >>> I > >>> believe that the "pinconf" subnode also needs to replicate the list of > >>> pins, or at least that's what we did everywhere else on sdm845 / > >>> sc7180. > >> > >> Yes. > >> > >>> > >>> Thus to match conventions, I assume you'd do: > >>> > >>> &qup_spi2_default { > >>> pinconf { > >> > >> No, because I want a convention of all pinctrl bindings and drivers, not > >> convention of old pinctrl ones. The new ones are already moved or being > >> moved to "-state" and "-pins". In the same time I am also unifying the > >> requirement of "function" property - enforcing it in each node, thus > >> "pinconf" will not be valid anymore. > > > > Regardless of where we want to end up, it feels like as of ${SUBJECT} > > patch this should match existing conventions in this file. If a later > > patch wants to change the conventions in this file then it can, but > > having just this one patch leaving things in an inconsistent state > > isn't great IMO... > > > > If this really has to be one-off then the subnode shouldn't be called > > "pinmux". A subnode called "pinmux" implies that it just has muxing > > information in it. After your patch this is called "pinmux" but has > > _configuration_ in it. > > > > It is a poor argument to keep some convention which is both > undocumented, not kept in this file and known only to some folks > (although that's effect of lack of documentation). Even the bindings do > not say it should be "pinconf" but they mention "config" in example. The > existing sdm845.dts uses config - so why now there should be "pinconf"? > By this "convention" we have both "pinmux" and "mux", perfect. Several > other pins do not have pinmux/mux/config at all. > > This convention was never implemented, so there is nothing to keep/match. > > Changing it to "config" (because this is the most used "convention" in > the file and bindings) would also mean to add useless "pins" which will > be in next patch removed. I certainly won't make the argument that the old convention was great or even that consistently followed. That's why it changed. ...but to me it's more that a patch should stand on its own and not only make sense in the context of future patches. After applying ${SUBJECT} patch you end up with a node called "pinmux" that has more than just muxing information in it. That seems less than ideal. -Doug
On 04/10/2022 01:03, Doug Anderson wrote: >>> If this really has to be one-off then the subnode shouldn't be called >>> "pinmux". A subnode called "pinmux" implies that it just has muxing >>> information in it. After your patch this is called "pinmux" but has >>> _configuration_ in it. >>> >> >> It is a poor argument to keep some convention which is both >> undocumented, not kept in this file and known only to some folks >> (although that's effect of lack of documentation). Even the bindings do >> not say it should be "pinconf" but they mention "config" in example. The >> existing sdm845.dts uses config - so why now there should be "pinconf"? >> By this "convention" we have both "pinmux" and "mux", perfect. Several >> other pins do not have pinmux/mux/config at all. >> >> This convention was never implemented, so there is nothing to keep/match. >> >> Changing it to "config" (because this is the most used "convention" in >> the file and bindings) would also mean to add useless "pins" which will >> be in next patch removed. > > I certainly won't make the argument that the old convention was great > or even that consistently followed. That's why it changed. ...but to > me it's more that a patch should stand on its own and not only make > sense in the context of future patches. After applying ${SUBJECT} > patch you end up with a node called "pinmux" that has more than just > muxing information in it. That seems less than ideal. OK, let me make it part of "config" then to match other nodes from DTSI. Best regards, Krzysztof
diff --git a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts index 132417e2d11e..a157eab66dee 100644 --- a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts +++ b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts @@ -1123,7 +1123,9 @@ &wifi { /* PINCTRL - additions to nodes defined in sdm845.dtsi */ &qup_spi2_default { - drive-strength = <16>; + pinmux { + drive-strength = <16>; + }; }; &qup_uart3_default{
The pin configuration (done with generic pin controller helpers and as expressed by bindings) requires children nodes with either: 1. "pins" property and the actual configuration, 2. another set of nodes with above point. The qup_spi2_default pin configuration used second method - with a "pinmux" child. Fixes: 8d23a0040475 ("arm64: dts: qcom: db845c: add Low speed expansion i2c and spi nodes") Cc: <stable@vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> --- Not tested on hardware. --- arch/arm64/boot/dts/qcom/sdm845-db845c.dts | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)