Re: [PATCH v1] ARM: dts: imx: tqma7: add lm75a sensor (rev. 01xxx)

jrodrigues
2023-11-09T09:27:07Z

Hi Alexander,

On Thu, 09 Nov 2023 07:57:36 +0100
Alexander Stein <alexander.stein@ew.tq-group.com> wrote:

> Hi João,
>
> Am Dienstag, 7. November 2023, 07:34:32 CET schrieb Alexander Stein:
> > Hi,
> >
> > Am Freitag, 3. November 2023, 22:07:08 CET schrieb Fabio Estevam:
> > > [Adding Bruno and Alexander]
> > >
> > > On Thu, Nov 2, 2023 at 7:12 PM João Rodrigues
> > > <jrodrigues@ubimet.com>
> wrote:
> > > > From: João Rodrigues <jrodrigues@ubimet.com>
> > > >
> > > > TQMa7x (revision 01xxx) uses a LM75A temperature sensor.
> > > > The two sensors use different I2C addresses, so we can set both
> > > > sensors simultaneously.
> >
> > I've contacted responsible department and I am waiting for more
> > details.
>
> I got response that REV.01xx was just a prototype and not released
> officially.

But REV. 01xx was not an internal-only prototype.
Furthermore, in the board manual,
https://www.tq-group.com/filedownloads/files/products/embedded/manuals/arm/carrierboard/MBa7x/MBa7x.UM.0101.pdf
section 4.1.2, the old version is still referenced.

>
> > Best regards,
> > Alexander
> >
> > > > Signed-off-by: João Rodrigues <jrodrigues@ubimet.com>
> > > > ---
> > > >
> > > > arch/arm/boot/dts/nxp/imx/imx7-tqma7.dtsi | 9 +++++++--
> > > > 1 file changed, 7 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/arch/arm/boot/dts/nxp/imx/imx7-tqma7.dtsi
> > > > b/arch/arm/boot/dts/nxp/imx/imx7-tqma7.dtsi index
> > > > fe42b0a4683..3fc3130f9de 100644
> > > > --- a/arch/arm/boot/dts/nxp/imx/imx7-tqma7.dtsi
> > > > +++ b/arch/arm/boot/dts/nxp/imx/imx7-tqma7.dtsi
> > > > @@ -128,11 +128,16 @@ vgen6_reg: vldo4 {
> > > >
> > > > };
> > > >
> > > > };
> > > >
> > > > - /* NXP SE97BTP with temperature sensor + eeprom */
> > > > + /* LM75A temperature sensor, TQMa7x 01xx */
> > > > + lm75a: temperature-sensor@48 {
> > > > + compatible = "national,lm75a";
> > > > + reg = <0x48>;
> > > > + };
>
> I don't like the idea of adding an i2c device for everybody. This
> restricts/ affects usage of i2c address 0x48 for all rev.02xx users,
> no?

Yes, it restricts the usage of I2C address 0x48 in I2C1.
While I2C1 is not exclusive to the SoM, the TQMa7x manual states
"I2C1 is used for devices on the TQMa7x".
As a counterpoint, the MBa7x carrier board also uses I2C1.

>
> Best regards,
> Alexander
> > > > +
> > > > + /* NXP SE97BTP with temperature sensor + eeprom, TQMa7x
> > > > 02xx */
> > > >
> > > > se97b: temperature-sensor-eeprom@1e {
> > > >
> > > > compatible = "nxp,se97b", "jedec,jc-42.4-temp";
> > > > reg = <0x1e>;
> > > >
> > > > - status = "okay";
> > > >
> > > > };
> > > >
> > > > /* ST M24C64 */
> > > >
> > > > --
> > > > 2.25.1
>
>