Re: [PATCH v2] can: tcan4x5x: put tcan into sleep when removing driver

Sean Nyekjaer <[email protected]> Mon, 03 Aug 2026 11:32:15 +0000
Newsgroups org.kernel.vger.linux-can,org.kernel.vger.linux-kernel
Message-ID <qeNtat9LVO8NCBxGCR2a4Lr0ugJ5k1TYM5OqX6V2hjWgKVArdIkxm8wX_DaFd_fQZbF3EyZ-Pv5CsRiy3LgrNiBlX0uw-rn9CawvevVQ6_8=@geanix.com>



On Monday, 3 August 2026 at 13:27, Marc Kleine-Budde <[email protected]> w=
rote:

> On 03.08.2026 12:19:26, Sean Nyekjaer wrote:
> > Put the tcan4x5x transceiver into sleep mode when the driver is
> > removed, instead of leaving it in its current operating mode.
> > This reduces power consumption(3mA@12V) once the driver is
> > no longer bound to the device.
> >
> > Signed-off-by: Sean Nyekjaer <[email protected]>
>=20
> Seems you patch is not complete:
>=20
> | drivers/net/can/m_can/tcan4x5x-core.c: In function =E2=80=98tcan4x5x_ca=
n_remove=E2=80=99:
> | drivers/net/can/m_can/tcan4x5x-core.c:552:35: error: passing argument 1=
 of =E2=80=98tcan4x5x_power_enable=E2=80=99 from incompatible pointer type =
[-Wincompatible-pointer-types]
> |   552 |         tcan4x5x_power_enable(priv->power, 0);
> |       |                               ~~~~^~~~~~~
> |       |                                   |
> |       |                                   struct regulator *
> | drivers/net/can/m_can/tcan4x5x-core.c:214:56: note: expected =E2=80=
=98struct tcan4x5x_priv *=E2=80=99 but argument is of type =E2=80=98struct =
regulator *=E2=80=99
> |   214 | static int tcan4x5x_power_enable(struct tcan4x5x_priv *priv, in=
t enable)
> |       |                                  ~~~~~~~~~~~~~~~~~~~~~~^~~~

Yes.

>=20
> > ---
> > Changes since v1:
> >  - Moved enter sleep mode into tcan4x5x_power_enable()
> >
> >  drivers/net/can/m_can/tcan4x5x-core.c | 18 ++++++++++++------
> >  1 file changed, 12 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/net/can/m_can/tcan4x5x-core.c b/drivers/net/can/m_=
can/tcan4x5x-core.c
> > index 31cc9d0abd45..67902b8b0fab 100644
> > --- a/drivers/net/can/m_can/tcan4x5x-core.c
> > +++ b/drivers/net/can/m_can/tcan4x5x-core.c
> > @@ -211,15 +211,21 @@ static int tcan4x5x_write_fifo(struct m_can_class=
dev *cdev,
> >  =09return regmap_bulk_write(priv->regmap, TCAN4X5X_MRAM_START + addr_o=
ffset, val, val_count);
> >  }
> >
> > -static int tcan4x5x_power_enable(struct regulator *reg, int enable)
> > +static int tcan4x5x_power_enable(struct tcan4x5x_priv *priv, int enabl=
e)
> >  {
>=20
> If you add:
>=20
>         struct regulator *reg =3D priv->power;
>=20
> the diff should be smaller.

Yes.

>=20
> > -=09if (IS_ERR_OR_NULL(reg))
> > +=09if (IS_ERR_OR_NULL(priv->power)) {
>=20
> Can you please add a comment that the reset GPIO is needed to get the
> device out of sleep mode.

Will do! Sorry first day after vacation.

/Sean