diff mbox series

[v2,3/4] usb: typec: tcpci: clear the fault status bit

Message ID 20230504-b4-v6-3-topic-boards-imx8mp-evk-dual-role-usb-v2-3-3889b1b2050c@pengutronix.de
State New
Headers
Series Add i.MX8MP-EVK USB Gadget Support |

Commit Message

Marco Felsch May 4, 2023, 1:46 p.m. UTC 
  According the "USB Type-C Port Controller Interface Specification v2.0"
the TCPC sets the fault status register bit-7
(AllRegistersResetToDefault) once the registers have been reseted to
their default values.

This triggers an alert(-irq) on PTN5110 devices albeit we do mask the
fault-irq. Fix this gernally by writing a one to the correspondig
bit-7.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 drivers/usb/typec/tcpm/tcpci.c | 5 +++++
 include/linux/usb/tcpci.h      | 1 +
 2 files changed, 6 insertions(+)

Comments

Guenter Roeck May 4, 2023, 2:08 p.m. UTC | #1 
On 5/4/23 06:46, Marco Felsch wrote:
> According the "USB Type-C Port Controller Interface Specification v2.0"
> the TCPC sets the fault status register bit-7
> (AllRegistersResetToDefault) once the registers have been reseted to

cleared ? set ?

> their default values.
> 
> This triggers an alert(-irq) on PTN5110 devices albeit we do mask the
> fault-irq. Fix this gernally by writing a one to the correspondig

generically ?

corresponding

> bit-7.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
>   drivers/usb/typec/tcpm/tcpci.c | 5 +++++
>   include/linux/usb/tcpci.h      | 1 +
>   2 files changed, 6 insertions(+)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index 8da23240afbe..15632d023e4c 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -602,6 +602,11 @@ static int tcpci_init(struct tcpc_dev *tcpc)
>   	if (time_after(jiffies, timeout))
>   		return -ETIMEDOUT;
>   
> +	regmap_read(tcpci->regmap, TCPC_FAULT_STATUS, &reg);

Needs error check.

Also, I am not sure if this is the correct place for this code. The alert
status is cleared after vendor initialization. Should the same be done
here ? Also, why not just write the bit unconditionally, similar
to TCPC_ALERT ?

Thanks,
Guenter

> +	if (reg & TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT)
> +		tcpci_write16(tcpci, TCPC_FAULT_STATUS,
> +			      TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
> +
>   	/* Handle vendor init */
>   	if (tcpci->data->init) {
>   		ret = tcpci->data->init(tcpci, tcpci->data);
> diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
> index 85e95a3251d3..83376473ac76 100644
> --- a/include/linux/usb/tcpci.h
> +++ b/include/linux/usb/tcpci.h
> @@ -103,6 +103,7 @@
>   #define TCPC_POWER_STATUS_SINKING_VBUS	BIT(0)
>   
>   #define TCPC_FAULT_STATUS		0x1f
> +#define TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT BIT(7)
>   
>   #define TCPC_ALERT_EXTENDED		0x21
>   
>
Marco Felsch May 4, 2023, 2:27 p.m. UTC | #2 
On 23-05-04, Guenter Roeck wrote:
> On 5/4/23 06:46, Marco Felsch wrote:
> > According the "USB Type-C Port Controller Interface Specification v2.0"
> > the TCPC sets the fault status register bit-7
> > (AllRegistersResetToDefault) once the registers have been reseted to
> 
> cleared ? set ?

Sry. I don't get this.

> > their default values.
> > 
> > This triggers an alert(-irq) on PTN5110 devices albeit we do mask the
> > fault-irq. Fix this gernally by writing a one to the correspondig
> 
> generically ?

Sure, thanks.

> corresponding

Of course!

> > bit-7.
> > 
> > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > ---
> >   drivers/usb/typec/tcpm/tcpci.c | 5 +++++
> >   include/linux/usb/tcpci.h      | 1 +
> >   2 files changed, 6 insertions(+)
> > 
> > diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> > index 8da23240afbe..15632d023e4c 100644
> > --- a/drivers/usb/typec/tcpm/tcpci.c
> > +++ b/drivers/usb/typec/tcpm/tcpci.c
> > @@ -602,6 +602,11 @@ static int tcpci_init(struct tcpc_dev *tcpc)
> >   	if (time_after(jiffies, timeout))
> >   		return -ETIMEDOUT;
> > +	regmap_read(tcpci->regmap, TCPC_FAULT_STATUS, &reg);
> 
> Needs error check.

I will add this.

> Also, I am not sure if this is the correct place for this code. The alert
> status is cleared after vendor initialization. Should the same be done
> here ?

According the spec the bit must be cleared before the TCPC_ALERT is
cleared. Of course the vendor-init can (re-)trigger the bit, therefore
we should move behind the vendor init and right before the TCPC_ALERT
clear.

> Also, why not just write the bit unconditionally, similar
> to TCPC_ALERT ?

Thought about this too.. I will change it in the v3.

Thanks for the feedback,
  Marco

> 
> Thanks,
> Guenter
> 
> > +	if (reg & TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT)
> > +		tcpci_write16(tcpci, TCPC_FAULT_STATUS,
> > +			      TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
> > +
> >   	/* Handle vendor init */
> >   	if (tcpci->data->init) {
> >   		ret = tcpci->data->init(tcpci, tcpci->data);
> > diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
> > index 85e95a3251d3..83376473ac76 100644
> > --- a/include/linux/usb/tcpci.h
> > +++ b/include/linux/usb/tcpci.h
> > @@ -103,6 +103,7 @@
> >   #define TCPC_POWER_STATUS_SINKING_VBUS	BIT(0)
> >   #define TCPC_FAULT_STATUS		0x1f
> > +#define TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT BIT(7)
> >   #define TCPC_ALERT_EXTENDED		0x21
> > 
> 
>
Guenter Roeck May 4, 2023, 3:27 p.m. UTC | #3 
On 5/4/23 07:27, Marco Felsch wrote:
> On 23-05-04, Guenter Roeck wrote:
>> On 5/4/23 06:46, Marco Felsch wrote:
>>> According the "USB Type-C Port Controller Interface Specification v2.0"
>>> the TCPC sets the fault status register bit-7
>>> (AllRegistersResetToDefault) once the registers have been reseted to
>>
>> cleared ? set ?
> 
> Sry. I don't get this.
> 

instead of "reseted" which isn't really a word.

>>> their default values.
>>>
>>> This triggers an alert(-irq) on PTN5110 devices albeit we do mask the
>>> fault-irq. Fix this gernally by writing a one to the correspondig
>>
>> generically ?
> 
> Sure, thanks.
> 
>> corresponding
> 
> Of course!
> 
>>> bit-7.
>>>
>>> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
>>> ---
>>>    drivers/usb/typec/tcpm/tcpci.c | 5 +++++
>>>    include/linux/usb/tcpci.h      | 1 +
>>>    2 files changed, 6 insertions(+)
>>>
>>> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
>>> index 8da23240afbe..15632d023e4c 100644
>>> --- a/drivers/usb/typec/tcpm/tcpci.c
>>> +++ b/drivers/usb/typec/tcpm/tcpci.c
>>> @@ -602,6 +602,11 @@ static int tcpci_init(struct tcpc_dev *tcpc)
>>>    	if (time_after(jiffies, timeout))
>>>    		return -ETIMEDOUT;
>>> +	regmap_read(tcpci->regmap, TCPC_FAULT_STATUS, &reg);
>>
>> Needs error check.
> 
> I will add this.
> 
>> Also, I am not sure if this is the correct place for this code. The alert
>> status is cleared after vendor initialization. Should the same be done
>> here ?
> 
> According the spec the bit must be cleared before the TCPC_ALERT is
> cleared. Of course the vendor-init can (re-)trigger the bit, therefore
> we should move behind the vendor init and right before the TCPC_ALERT
> clear.
> 
>> Also, why not just write the bit unconditionally, similar
>> to TCPC_ALERT ?
> 
> Thought about this too.. I will change it in the v3.
> 
> Thanks for the feedback,
>    Marco
> 
>>
>> Thanks,
>> Guenter
>>
>>> +	if (reg & TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT)
>>> +		tcpci_write16(tcpci, TCPC_FAULT_STATUS,
>>> +			      TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
>>> +
>>>    	/* Handle vendor init */
>>>    	if (tcpci->data->init) {
>>>    		ret = tcpci->data->init(tcpci, tcpci->data);
>>> diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
>>> index 85e95a3251d3..83376473ac76 100644
>>> --- a/include/linux/usb/tcpci.h
>>> +++ b/include/linux/usb/tcpci.h
>>> @@ -103,6 +103,7 @@
>>>    #define TCPC_POWER_STATUS_SINKING_VBUS	BIT(0)
>>>    #define TCPC_FAULT_STATUS		0x1f
>>> +#define TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT BIT(7)
>>>    #define TCPC_ALERT_EXTENDED		0x21
>>>
>>
>>
Marco Felsch May 4, 2023, 4:52 p.m. UTC | #4 
On 23-05-04, Guenter Roeck wrote:
> On 5/4/23 07:27, Marco Felsch wrote:
> > On 23-05-04, Guenter Roeck wrote:
> > > On 5/4/23 06:46, Marco Felsch wrote:
> > > > According the "USB Type-C Port Controller Interface Specification v2.0"
> > > > the TCPC sets the fault status register bit-7
> > > > (AllRegistersResetToDefault) once the registers have been reseted to
> > > 
> > > cleared ? set ?
> > 
> > Sry. I don't get this.
> > 
> 
> instead of "reseted" which isn't really a word.

Sure, thanks.

Regards,
  Marco
Marco Felsch Aug. 17, 2023, 8 a.m. UTC | #5 
On 23-08-16, Fabio Estevam wrote:
> Hi Marco,
> 
> On Thu, May 4, 2023 at 11:27 AM Marco Felsch <m.felsch@pengutronix.de> wrote:
> 
> > > Also, why not just write the bit unconditionally, similar
> > > to TCPC_ALERT ?
> >
> > Thought about this too.. I will change it in the v3.
> 
> Was there ever a v3 for this patch?

Nope, thanks for sending it separate :)

Regards,
  Marco
diff mbox series

Patch

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index 8da23240afbe..15632d023e4c 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -602,6 +602,11 @@  static int tcpci_init(struct tcpc_dev *tcpc)
 	if (time_after(jiffies, timeout))
 		return -ETIMEDOUT;
 
+	regmap_read(tcpci->regmap, TCPC_FAULT_STATUS, &reg);
+	if (reg & TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT)
+		tcpci_write16(tcpci, TCPC_FAULT_STATUS,
+			      TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
+
 	/* Handle vendor init */
 	if (tcpci->data->init) {
 		ret = tcpci->data->init(tcpci, tcpci->data);
diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
index 85e95a3251d3..83376473ac76 100644
--- a/include/linux/usb/tcpci.h
+++ b/include/linux/usb/tcpci.h
@@ -103,6 +103,7 @@ 
 #define TCPC_POWER_STATUS_SINKING_VBUS	BIT(0)
 
 #define TCPC_FAULT_STATUS		0x1f
+#define TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT BIT(7)
 
 #define TCPC_ALERT_EXTENDED		0x21