Re: [PATCH] mfd: tps65219: Add support for soft shutdown via sys-off API

[Andrew Davis]

On 3/1/23 10:07 AM, Lee Jones wrote:
> On Fri, 03 Feb 2023, Jerome Neanne wrote:
>
> > Use new API for power-off mode support:
> > Link: https://lwn.net/Articles/894511/
> > Link: https://lore.kernel.org/all/7hfseqa7l0.fsf@xxxxxxxxxxxx/
> >
> > sys-off API allows support of shutdown handler and restart handler.
> >
> > Shutdown was not supported before that enhancement.
> > This is required for platform that are not using PSCI.

Not sure what platform doesn't have PSCI off, since you tested on
AM62-SK I'm guessing you manually disabled the PSCI off for testing?

Anyway I don't see any huge issues with the code itself, small comment below.

> > Test:
> > - restart:
> >    # reboot
> >    Default is cold reset:
> >    # cat /sys/kernel/reboot/mode
> >    Switch boot mode to warm reset:
> >    # echo warm > /sys/kernel/reboot/mode
> > - power-off:
> >    # halt
> >
> > Tested on AM62-SP-SK board.
> >
> > Signed-off-by: Jerome Neanne <jneanne@xxxxxxxxxxxx>
> > Suggested-by: Andrew Davis <afd@xxxxxx>
>
> A review from Andrew would be helpful here.
>
> > ---
> >   drivers/mfd/tps65219.c | 45 +++++++++++++++++++++++++++++++-----------
> >   1 file changed, 34 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/mfd/tps65219.c b/drivers/mfd/tps65219.c
> > index 0e402fda206b..c134f3f6e202 100644
> > --- a/drivers/mfd/tps65219.c
> > +++ b/drivers/mfd/tps65219.c
> > @@ -25,25 +25,34 @@ static int tps65219_cold_reset(struct tps65219 *tps)
> >   				  TPS65219_MFP_COLD_RESET_I2C_CTRL_MASK);
> >   }
> >   
> > -static int tps65219_restart(struct notifier_block *this,
> > -			    unsigned long reboot_mode, void *cmd)
> > +static int tps65219_soft_shutdown(struct tps65219 *tps)
> >   {
> > -	struct tps65219 *tps;
> > +	return regmap_update_bits(tps->regmap, TPS65219_REG_MFP_CTRL,
> > +				  TPS65219_MFP_I2C_OFF_REQ_MASK,
> > +				  TPS65219_MFP_I2C_OFF_REQ_MASK);
> > +}
> >   
> > -	tps = container_of(this, struct tps65219, nb);
> > +static int tps65219_power_off_handler(struct sys_off_data *data)
> > +{
> > +	tps65219_soft_shutdown(data->cb_data);
> > +	return NOTIFY_DONE;
> > +}
> >   
> > +static int tps65219_restart(struct tps65219 *tps,
> > +			    unsigned long reboot_mode)
> > +{
> >   	if (reboot_mode == REBOOT_WARM)
> >   		tps65219_warm_reset(tps);
> >   	else
> >   		tps65219_cold_reset(tps);
> > -
> >   	return NOTIFY_DONE;
> >   }
> >   
> > -static struct notifier_block pmic_rst_restart_nb = {
> > -	.notifier_call = tps65219_restart,
> > -	.priority = 200,
> > -};
> > +static int tps65219_restart_handler(struct sys_off_data *data)
> > +{
> > +	tps65219_restart(data->cb_data, data->mode);
> > +	return NOTIFY_DONE;
> > +}
> >   
> >   static const struct resource tps65219_pwrbutton_resources[] = {
> >   	DEFINE_RES_IRQ_NAMED(TPS65219_INT_PB_FALLING_EDGE_DETECT, "falling"),
> > @@ -269,13 +278,27 @@ static int tps65219_probe(struct i2c_client *client)
> >   		}
> >   	}
> >   
> > -	tps->nb = pmic_rst_restart_nb;
> > -	ret = register_restart_handler(&tps->nb);
> > +	ret = devm_register_sys_off_handler(tps->dev,
> > +					    SYS_OFF_MODE_RESTART,
> > +					    SYS_OFF_PRIO_HIGH,

Why not default prio? SYS_OFF_PRIO_DEFAULT

Then you can use this new helper devm_register_restart_handler()

> > +					    tps65219_restart_handler,
> > +					    tps);
> > +
> >   	if (ret) {
> >   		dev_err(tps->dev, "cannot register restart handler, %d\n", ret);
> >   		return ret;
> >   	}
> >   
> > +	ret = devm_register_sys_off_handler(tps->dev,
> > +					    SYS_OFF_MODE_POWER_OFF,
> > +					    SYS_OFF_PRIO_DEFAULT,
> > +					    tps65219_power_off_handler,
> > +					    tps);


devm_register_power_off_handler()?

Otherwise I see no major issues,

Reviewed-by: Andrew Davis <afd@xxxxxx>

Andrew

> > +	if (ret) {
> > +		dev_err(tps->dev, "failed to register sys-off handler: %d\n",
> > +			ret);
> > +		return ret;
> > +	}
> >   	return 0;
> >   }
> >   
> > --
> > 2.34.1