* Re: [PATCH v2 2/2] iio:temperature:max31856:Add device tree bind info
[not found] ` <1539275890-38141-2-git-send-email-matthew.weber@rockwellcollins.com>
@ 2018-10-13 13:54 ` Jonathan Cameron
2018-10-16 22:16 ` Paresh Chaudhary
0 siblings, 1 reply; 3+ messages in thread
From: Jonathan Cameron @ 2018-10-13 13:54 UTC (permalink / raw)
To: Matt Weber
Cc: linux-iio, knaack.h, lars, pmeerw, Paresh Chaudhary, devicetree,
Rob Herring, Mark Rutland
On Thu, 11 Oct 2018 11:38:10 -0500
Matt Weber <matthew.weber@rockwellcollins.com> wrote:
> From: Paresh Chaudhary <paresh.chaudhary@rockwellcollins.com>
>
> This patch added device tree binding info for MAX31856 driver.
>
> Signed-off-by: Paresh Chaudhary <paresh.chaudhary@rockwellcollins.com>
> Signed-off-by: Matt Weber <matthew.weber@rockwellcollins.com>
Device tree bindings should be cc'd to the devicetree list and maintainers.
Thanks,
Jonathan
> ---
> Changes v1 -> v2
> [Matt
> - Removed comment block and added possibilities of
> thermocouple type in device tree binding doc.
>
> ---
> .../bindings/iio/temperature/max31856.txt | 32 ++++++++++++++++++++++
> MAINTAINERS | 1 +
> 2 files changed, 33 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/temperature/max31856.txt
>
> diff --git a/Documentation/devicetree/bindings/iio/temperature/max31856.txt b/Documentation/devicetree/bindings/iio/temperature/max31856.txt
> new file mode 100644
> index 0000000..e1def9f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/temperature/max31856.txt
> @@ -0,0 +1,32 @@
> +Maxim MAX31856 thermocouple support
> +
> +https://datasheets.maximintegrated.com/en/ds/MAX31856.pdf
> +
> +Required properties:
> + - compatible: must be "max31856"
> + - reg: SPI chip select number for the device
> + - spi-max-frequency: As per datasheet max. supported freq is 5000000
> + - spi-cpha: must be defined for max31856 to enable SPI mode 1
> + - type: Type of thermocouple (By default is K-Type)
> + 0x00 : TYPE_B
> + 0x01 : TYPE_E
> + 0x02 : TYPE_J
> + 0x03 : TYPE_K (default)
> + 0x04 : TYPE_N
> + 0x05 : TYPE_R
> + 0x06 : TYPE_S
> + 0x07 : TYPE_T
> +
> + Refer to spi/spi-bus.txt for generic SPI slave bindings.
> +
> +Optional properties:
> + - one-shot: Enable one-shot Conversion mode (By default mode is auto)
Why is this something that should be in devicetree rather than controlled
in the driver in response to some userspace interaction?
> +
> + Example:
> + max31856@0 {
> + compatible = "max31856";
> + reg = <0>;
> + spi-max-frequency = <5000000>;
> + spi-cpha;
> + type = <0x03>;
> + };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index dd9a83d..6482ae8 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -7161,6 +7161,7 @@ MAX31856 IIO DRIVER
> M: Matthew Weber <matthew.weber@rockwellcollins.com>
> S: Maintained
> F: drivers/iio/temperature/max31856.c
> +F: Documentation/devicetree/bindings/iio/temperature/max31856.txt
>
> IIO UNIT CONVERTER
> M: Peter Rosin <peda@axentia.se>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2 2/2] iio:temperature:max31856:Add device tree bind info
2018-10-13 13:54 ` [PATCH v2 2/2] iio:temperature:max31856:Add device tree bind info Jonathan Cameron
@ 2018-10-16 22:16 ` Paresh Chaudhary
2018-10-21 14:19 ` Jonathan Cameron
0 siblings, 1 reply; 3+ messages in thread
From: Paresh Chaudhary @ 2018-10-16 22:16 UTC (permalink / raw)
To: jic23
Cc: Matthew Weber, linux-iio, knaack.h, lars, pmeerw, devicetree,
robh+dt, mark.rutland
Hi Jonathan,
Please find my comment inline.
Thanks,
Paresh
On Sat, Oct 13, 2018 at 8:54 AM Jonathan Cameron <jic23@kernel.org> wrote:
>
> On Thu, 11 Oct 2018 11:38:10 -0500
> Matt Weber <matthew.weber@rockwellcollins.com> wrote:
>
> > From: Paresh Chaudhary <paresh.chaudhary@rockwellcollins.com>
> >
> > This patch added device tree binding info for MAX31856 driver.
> >
> > Signed-off-by: Paresh Chaudhary <paresh.chaudhary@rockwellcollins.com>
> > Signed-off-by: Matt Weber <matthew.weber@rockwellcollins.com>
> Device tree bindings should be cc'd to the devicetree list and maintainers.
>
> Thanks,
>
> Jonathan
>
> > ---
> > Changes v1 -> v2
> > [Matt
> > - Removed comment block and added possibilities of
> > thermocouple type in device tree binding doc.
> >
> > ---
> > .../bindings/iio/temperature/max31856.txt | 32 ++++++++++++++++++++++
> > MAINTAINERS | 1 +
> > 2 files changed, 33 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/iio/temperature/max31856.txt
> >
> > diff --git a/Documentation/devicetree/bindings/iio/temperature/max31856.txt b/Documentation/devicetree/bindings/iio/temperature/max31856.txt
> > new file mode 100644
> > index 0000000..e1def9f
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/temperature/max31856.txt
> > @@ -0,0 +1,32 @@
> > +Maxim MAX31856 thermocouple support
> > +
> > +https://datasheets.maximintegrated.com/en/ds/MAX31856.pdf
> > +
> > +Required properties:
> > + - compatible: must be "max31856"
> > + - reg: SPI chip select number for the device
> > + - spi-max-frequency: As per datasheet max. supported freq is 5000000
> > + - spi-cpha: must be defined for max31856 to enable SPI mode 1
> > + - type: Type of thermocouple (By default is K-Type)
> > + 0x00 : TYPE_B
> > + 0x01 : TYPE_E
> > + 0x02 : TYPE_J
> > + 0x03 : TYPE_K (default)
> > + 0x04 : TYPE_N
> > + 0x05 : TYPE_R
> > + 0x06 : TYPE_S
> > + 0x07 : TYPE_T
> > +
> > + Refer to spi/spi-bus.txt for generic SPI slave bindings.
> > +
> > +Optional properties:
> > + - one-shot: Enable one-shot Conversion mode (By default mode is auto)
>
> Why is this something that should be in devicetree rather than controlled
> in the driver in response to some userspace interaction?
>
>
There is no specific reason. This is just providing info to the driver
so the driver can configure chip while probe for specified mode.
I understand your concern but as of now, the driver does not have
support to decide mode based on userspace interaction. We will work on
that when we reopen for enhancement (e.g threshold for temp. range)
> > +
> > + Example:
> > + max31856@0 {
> > + compatible = "max31856";
> > + reg = <0>;
> > + spi-max-frequency = <5000000>;
> > + spi-cpha;
> > + type = <0x03>;
> > + };
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index dd9a83d..6482ae8 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -7161,6 +7161,7 @@ MAX31856 IIO DRIVER
> > M: Matthew Weber <matthew.weber@rockwellcollins.com>
> > S: Maintained
> > F: drivers/iio/temperature/max31856.c
> > +F: Documentation/devicetree/bindings/iio/temperature/max31856.txt
> >
> > IIO UNIT CONVERTER
> > M: Peter Rosin <peda@axentia.se>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2 2/2] iio:temperature:max31856:Add device tree bind info
2018-10-16 22:16 ` Paresh Chaudhary
@ 2018-10-21 14:19 ` Jonathan Cameron
0 siblings, 0 replies; 3+ messages in thread
From: Jonathan Cameron @ 2018-10-21 14:19 UTC (permalink / raw)
To: Paresh Chaudhary
Cc: Matthew Weber, linux-iio, knaack.h, lars, pmeerw, devicetree,
robh+dt, mark.rutland
On Tue, 16 Oct 2018 17:16:15 -0500
Paresh Chaudhary <paresh.chaudhary@rockwellcollins.com> wrote:
> Hi Jonathan,
>
> Please find my comment inline.
>
> Thanks,
> Paresh
>
> On Sat, Oct 13, 2018 at 8:54 AM Jonathan Cameron <jic23@kernel.org> wrote:
> >
> > On Thu, 11 Oct 2018 11:38:10 -0500
> > Matt Weber <matthew.weber@rockwellcollins.com> wrote:
> >
> > > From: Paresh Chaudhary <paresh.chaudhary@rockwellcollins.com>
> > >
> > > This patch added device tree binding info for MAX31856 driver.
> > >
> > > Signed-off-by: Paresh Chaudhary <paresh.chaudhary@rockwellcollins.com>
> > > Signed-off-by: Matt Weber <matthew.weber@rockwellcollins.com>
> > Device tree bindings should be cc'd to the devicetree list and maintainers.
> >
> > Thanks,
> >
> > Jonathan
> >
> > > ---
> > > Changes v1 -> v2
> > > [Matt
> > > - Removed comment block and added possibilities of
> > > thermocouple type in device tree binding doc.
> > >
> > > ---
> > > .../bindings/iio/temperature/max31856.txt | 32 ++++++++++++++++++++++
> > > MAINTAINERS | 1 +
> > > 2 files changed, 33 insertions(+)
> > > create mode 100644 Documentation/devicetree/bindings/iio/temperature/max31856.txt
> > >
> > > diff --git a/Documentation/devicetree/bindings/iio/temperature/max31856.txt b/Documentation/devicetree/bindings/iio/temperature/max31856.txt
> > > new file mode 100644
> > > index 0000000..e1def9f
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/iio/temperature/max31856.txt
> > > @@ -0,0 +1,32 @@
> > > +Maxim MAX31856 thermocouple support
> > > +
> > > +https://datasheets.maximintegrated.com/en/ds/MAX31856.pdf
> > > +
> > > +Required properties:
> > > + - compatible: must be "max31856"
> > > + - reg: SPI chip select number for the device
> > > + - spi-max-frequency: As per datasheet max. supported freq is 5000000
> > > + - spi-cpha: must be defined for max31856 to enable SPI mode 1
> > > + - type: Type of thermocouple (By default is K-Type)
> > > + 0x00 : TYPE_B
> > > + 0x01 : TYPE_E
> > > + 0x02 : TYPE_J
> > > + 0x03 : TYPE_K (default)
> > > + 0x04 : TYPE_N
> > > + 0x05 : TYPE_R
> > > + 0x06 : TYPE_S
> > > + 0x07 : TYPE_T
> > > +
> > > + Refer to spi/spi-bus.txt for generic SPI slave bindings.
> > > +
> > > +Optional properties:
> > > + - one-shot: Enable one-shot Conversion mode (By default mode is auto)
> >
> > Why is this something that should be in devicetree rather than controlled
> > in the driver in response to some userspace interaction?
> >
> >
> There is no specific reason. This is just providing info to the driver
> so the driver can configure chip while probe for specified mode.
> I understand your concern but as of now, the driver does not have
> support to decide mode based on userspace interaction. We will work on
> that when we reopen for enhancement (e.g threshold for temp. range)
Hmm. The problem is that this should not be a devicetree decision and
if we allow it to be so, then we end up stuck with having to support
the interface here going forward. It also sets a precedence that
will get picked up by other drivers.
So, sorry but I really don't think this is a good idea. For now you
may just have pick a default and go with it until you have the time
to add some automated switching between them at some later date.
Jonathan
> > > +
> > > + Example:
> > > + max31856@0 {
> > > + compatible = "max31856";
> > > + reg = <0>;
> > > + spi-max-frequency = <5000000>;
> > > + spi-cpha;
> > > + type = <0x03>;
> > > + };
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index dd9a83d..6482ae8 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -7161,6 +7161,7 @@ MAX31856 IIO DRIVER
> > > M: Matthew Weber <matthew.weber@rockwellcollins.com>
> > > S: Maintained
> > > F: drivers/iio/temperature/max31856.c
> > > +F: Documentation/devicetree/bindings/iio/temperature/max31856.txt
> > >
> > > IIO UNIT CONVERTER
> > > M: Peter Rosin <peda@axentia.se>
> >
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-10-21 14:19 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <1539275890-38141-1-git-send-email-matthew.weber@rockwellcollins.com>
[not found] ` <1539275890-38141-2-git-send-email-matthew.weber@rockwellcollins.com>
2018-10-13 13:54 ` [PATCH v2 2/2] iio:temperature:max31856:Add device tree bind info Jonathan Cameron
2018-10-16 22:16 ` Paresh Chaudhary
2018-10-21 14:19 ` Jonathan Cameron
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).