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

Marc Kleine-Budde <[email protected]> Mon, 27 Jul 2026 12:06:36 +0200

Newsgroups	org.kernel.vger.linux-can,org.kernel.vger.linux-kernel
Message-ID	<[email protected]>

On 27.07.2026 11:48:59, Sean Nyekjaer wrote:
> Put the tcan4x5x transceiver into sleep mode when the driver is

Ah, the device has an internal transceiver.

> 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.
>
> Note that the reset pin is needed to bring the device out of sleep
> and back into standby mode again.

Please add a comment, that the reset pin is needed and maybe refer to
"8.4.3 Sleep Mode" of https://www.ti.com/lit/gpn/tcan4550

Does it still work, if you move the regmap_update_bits() to
tcan4x5x_power_enable()?

> Signed-off-by: Sean Nyekjaer <[email protected]>
> ---
> I havn't come across any drivers that leaves the devices in the lowest
> power mode when unbinded. But we need this to enter our lowest power
> mode in suspend.
> If it doesn't fit in, I'm happy to carry this out of tree...

The mcp251xfd driver puts the device into sleep mode.

regards,
Marc

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