usb: typec: tcpci: add alert.fault handling

[PATCH] usb: typec: tcpci: add alert.fault handling

Posted by Marco Felsch 2 months ago

Add minimal handling to clear the ALERT.Fault bit which may be set in
case of an over-current or over-voltage detection. At the moment only
the IRQ clear support is added since the TCPC Spec mentions that the
handling of such events is vendor specific.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 drivers/usb/typec/tcpm/tcpci.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index a56e31b20c21..d2d5bf7ca618 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -692,7 +692,8 @@ static int tcpci_init(struct tcpc_dev *tcpc)
 
 	reg = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_FAILED |
 		TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_RX_STATUS |
-		TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS;
+		TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS |
+		TCPC_ALERT_FAULT;
 	if (tcpci->controls_vbus)
 		reg |= TCPC_ALERT_POWER_STATUS;
 	/* Enable VSAFE0V status interrupt when detecting VSAFE0V is supported */
@@ -720,6 +721,19 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
 	irq_ret = status & tcpci->alert_mask;
 
 process_status:
+	/*
+	 * Handle nested fault before clearing the alert status to not
+	 * re-trigger a fault alert immediately again.
+	 */
+	if (status & TCPC_ALERT_FAULT) {
+		unsigned int fault;
+
+		/* TODO: Add a proper over-current and over-voltage handling */
+		ret = regmap_read(tcpci->regmap, TCPC_FAULT_STATUS, &fault);
+		if (!ret)
+			regmap_write(tcpci->regmap, TCPC_FAULT_STATUS, fault);
+	}
+
 	/*
 	 * Clear alert status for everything except RX_STATUS, which shouldn't
 	 * be cleared until we have successfully retrieved message.
-- 
2.47.3

Re: [PATCH] usb: typec: tcpci: add alert.fault handling

Posted by Heikki Krogerus 1 month, 4 weeks ago

On Fri, Jul 31, 2026 at 10:34:59AM +0200, Marco Felsch wrote:
> Add minimal handling to clear the ALERT.Fault bit which may be set in
> case of an over-current or over-voltage detection. At the moment only
> the IRQ clear support is added since the TCPC Spec mentions that the
> handling of such events is vendor specific.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
>  drivers/usb/typec/tcpm/tcpci.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index a56e31b20c21..d2d5bf7ca618 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -692,7 +692,8 @@ static int tcpci_init(struct tcpc_dev *tcpc)
>  
>  	reg = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_FAILED |
>  		TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_RX_STATUS |
> -		TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS;
> +		TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS |
> +		TCPC_ALERT_FAULT;
>  	if (tcpci->controls_vbus)
>  		reg |= TCPC_ALERT_POWER_STATUS;
>  	/* Enable VSAFE0V status interrupt when detecting VSAFE0V is supported */
> @@ -720,6 +721,19 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
>  	irq_ret = status & tcpci->alert_mask;
>  
>  process_status:
> +	/*
> +	 * Handle nested fault before clearing the alert status to not
> +	 * re-trigger a fault alert immediately again.
> +	 */

Shouldn't that explanation in the comment be also in the commit
message? That sounds like the "why" part to me.

> +	if (status & TCPC_ALERT_FAULT) {
> +		unsigned int fault;
> +
> +		/* TODO: Add a proper over-current and over-voltage handling */
> +		ret = regmap_read(tcpci->regmap, TCPC_FAULT_STATUS, &fault);
> +		if (!ret)
> +			regmap_write(tcpci->regmap, TCPC_FAULT_STATUS, fault);
> +	}
> +
>  	/*
>  	 * Clear alert status for everything except RX_STATUS, which shouldn't
>  	 * be cleared until we have successfully retrieved message.
> -- 
> 2.47.3

-- 
heikki

Re: [PATCH] usb: typec: tcpci: add alert.fault handling

Posted by Marco Felsch 1 month, 3 weeks ago

On 26-08-05, Heikki Krogerus wrote:
> On Fri, Jul 31, 2026 at 10:34:59AM +0200, Marco Felsch wrote:
> > Add minimal handling to clear the ALERT.Fault bit which may be set in
> > case of an over-current or over-voltage detection. At the moment only
> > the IRQ clear support is added since the TCPC Spec mentions that the
> > handling of such events is vendor specific.
> > 
> > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > ---
> >  drivers/usb/typec/tcpm/tcpci.c | 16 +++++++++++++++-
> >  1 file changed, 15 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> > index a56e31b20c21..d2d5bf7ca618 100644
> > --- a/drivers/usb/typec/tcpm/tcpci.c
> > +++ b/drivers/usb/typec/tcpm/tcpci.c
> > @@ -692,7 +692,8 @@ static int tcpci_init(struct tcpc_dev *tcpc)
> >  
> >  	reg = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_FAILED |
> >  		TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_RX_STATUS |
> > -		TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS;
> > +		TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS |
> > +		TCPC_ALERT_FAULT;
> >  	if (tcpci->controls_vbus)
> >  		reg |= TCPC_ALERT_POWER_STATUS;
> >  	/* Enable VSAFE0V status interrupt when detecting VSAFE0V is supported */
> > @@ -720,6 +721,19 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
> >  	irq_ret = status & tcpci->alert_mask;
> >  
> >  process_status:
> > +	/*
> > +	 * Handle nested fault before clearing the alert status to not
> > +	 * re-trigger a fault alert immediately again.
> > +	 */
> 
> Shouldn't that explanation in the comment be also in the commit
> message? That sounds like the "why" part to me.

I don't think so, it's just a comment for $dev that this ordering is
important. The commit message clearly states that an over-current or
over-voltage may trigger this.

Regards,
  Marco

> > +	if (status & TCPC_ALERT_FAULT) {
> > +		unsigned int fault;
> > +
> > +		/* TODO: Add a proper over-current and over-voltage handling */
> > +		ret = regmap_read(tcpci->regmap, TCPC_FAULT_STATUS, &fault);
> > +		if (!ret)
> > +			regmap_write(tcpci->regmap, TCPC_FAULT_STATUS, fault);
> > +	}
> > +
> >  	/*
> >  	 * Clear alert status for everything except RX_STATUS, which shouldn't
> >  	 * be cleared until we have successfully retrieved message.
> > -- 
> > 2.47.3
> 
> -- 
> heikki
> 

-- 
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Re: [PATCH] usb: typec: tcpci: add alert.fault handling

Posted by Heikki Krogerus 1 month, 3 weeks ago

On Wed, Aug 05, 2026 at 03:45:20PM +0200, Marco Felsch wrote:
> On 26-08-05, Heikki Krogerus wrote:
> > On Fri, Jul 31, 2026 at 10:34:59AM +0200, Marco Felsch wrote:
> > > Add minimal handling to clear the ALERT.Fault bit which may be set in
> > > case of an over-current or over-voltage detection. At the moment only
> > > the IRQ clear support is added since the TCPC Spec mentions that the
> > > handling of such events is vendor specific.
> > > 
> > > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > > ---
> > >  drivers/usb/typec/tcpm/tcpci.c | 16 +++++++++++++++-
> > >  1 file changed, 15 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> > > index a56e31b20c21..d2d5bf7ca618 100644
> > > --- a/drivers/usb/typec/tcpm/tcpci.c
> > > +++ b/drivers/usb/typec/tcpm/tcpci.c
> > > @@ -692,7 +692,8 @@ static int tcpci_init(struct tcpc_dev *tcpc)
> > >  
> > >  	reg = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_FAILED |
> > >  		TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_RX_STATUS |
> > > -		TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS;
> > > +		TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS |
> > > +		TCPC_ALERT_FAULT;
> > >  	if (tcpci->controls_vbus)
> > >  		reg |= TCPC_ALERT_POWER_STATUS;
> > >  	/* Enable VSAFE0V status interrupt when detecting VSAFE0V is supported */
> > > @@ -720,6 +721,19 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
> > >  	irq_ret = status & tcpci->alert_mask;
> > >  
> > >  process_status:
> > > +	/*
> > > +	 * Handle nested fault before clearing the alert status to not
> > > +	 * re-trigger a fault alert immediately again.
> > > +	 */
> > 
> > Shouldn't that explanation in the comment be also in the commit
> > message? That sounds like the "why" part to me.
> 
> I don't think so, it's just a comment for $dev that this ordering is
> important. The commit message clearly states that an over-current or
> over-voltage may trigger this.

Fair enough. Let's wait for Badhri, but FWIW:

Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

-- 
heikki