[PATCH v2] usb: typec: tcpm: Use configured PD revision for negotiation

[PATCH v2] usb: typec: tcpm: Use configured PD revision for negotiation

[Cosmo Chou]

Initialize negotiated_rev and negotiated_rev_prime based on the port's
configured PD revision (rev_major) rather than always defaulting to
PD_MAX_REV. This ensures ports start PD communication using their
appropriate revision level.

This allows proper communication with devices that require specific
PD revision levels, especially for the hardware designed for PD 1.0
or 2.0 specifications.

Signed-off-by: Cosmo Chou <chou.cosmo@gmail.com>
---
Change log:

v2:
  - Add PD_CAP_REVXX macros and use switch-case for better readability.

---
 drivers/usb/typec/tcpm/tcpm.c | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 8adf6f954633..48e9cfc2b49a 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -313,6 +313,10 @@ struct pd_data {
 	unsigned int operating_snk_mw;
 };
 
+#define PD_CAP_REV10	0x1
+#define PD_CAP_REV20	0x2
+#define PD_CAP_REV30	0x3
+
 struct pd_revision_info {
 	u8 rev_major;
 	u8 rev_minor;
@@ -4665,6 +4669,25 @@ static void tcpm_set_initial_svdm_version(struct tcpm_port *port)
 	}
 }
 
+static void tcpm_set_initial_negotiated_rev(struct tcpm_port *port)
+{
+	switch (port->pd_rev.rev_major) {
+	case PD_CAP_REV10:
+		port->negotiated_rev = PD_REV10;
+		break;
+	case PD_CAP_REV20:
+		port->negotiated_rev = PD_REV20;
+		break;
+	case PD_CAP_REV30:
+		port->negotiated_rev = PD_REV30;
+		break;
+	default:
+		port->negotiated_rev = PD_MAX_REV;
+		break;
+	}
+	port->negotiated_rev_prime = port->negotiated_rev;
+}
+
 static void run_state_machine(struct tcpm_port *port)
 {
 	int ret;
@@ -4782,8 +4805,7 @@ static void run_state_machine(struct tcpm_port *port)
 		typec_set_pwr_opmode(port->typec_port, opmode);
 		port->pwr_opmode = TYPEC_PWR_MODE_USB;
 		port->caps_count = 0;
-		port->negotiated_rev = PD_MAX_REV;
-		port->negotiated_rev_prime = PD_MAX_REV;
+		tcpm_set_initial_negotiated_rev(port);
 		port->message_id = 0;
 		port->message_id_prime = 0;
 		port->rx_msgid = -1;
@@ -5048,8 +5070,7 @@ static void run_state_machine(struct tcpm_port *port)
 					      port->cc2 : port->cc1);
 		typec_set_pwr_opmode(port->typec_port, opmode);
 		port->pwr_opmode = TYPEC_PWR_MODE_USB;
-		port->negotiated_rev = PD_MAX_REV;
-		port->negotiated_rev_prime = PD_MAX_REV;
+		tcpm_set_initial_negotiated_rev(port);
 		port->message_id = 0;
 		port->message_id_prime = 0;
 		port->rx_msgid = -1;
-- 
2.43.0

Re: [PATCH v2] usb: typec: tcpm: Use configured PD revision for negotiation

[Heikki Krogerus]

On Tue, May 13, 2025 at 09:08:34PM +0800, Cosmo Chou wrote:
> Initialize negotiated_rev and negotiated_rev_prime based on the port's
> configured PD revision (rev_major) rather than always defaulting to
> PD_MAX_REV. This ensures ports start PD communication using their
> appropriate revision level.
> 
> This allows proper communication with devices that require specific
> PD revision levels, especially for the hardware designed for PD 1.0
> or 2.0 specifications.
> 
> Signed-off-by: Cosmo Chou <chou.cosmo@gmail.com>
> ---
> Change log:
> 
> v2:
>   - Add PD_CAP_REVXX macros and use switch-case for better readability.
> 
> ---
>  drivers/usb/typec/tcpm/tcpm.c | 29 +++++++++++++++++++++++++----
>  1 file changed, 25 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 8adf6f954633..48e9cfc2b49a 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -313,6 +313,10 @@ struct pd_data {
>  	unsigned int operating_snk_mw;
>  };
>  
> +#define PD_CAP_REV10	0x1
> +#define PD_CAP_REV20	0x2
> +#define PD_CAP_REV30	0x3
> +
>  struct pd_revision_info {
>  	u8 rev_major;
>  	u8 rev_minor;
> @@ -4665,6 +4669,25 @@ static void tcpm_set_initial_svdm_version(struct tcpm_port *port)
>  	}
>  }
>  
> +static void tcpm_set_initial_negotiated_rev(struct tcpm_port *port)
> +{
> +	switch (port->pd_rev.rev_major) {
> +	case PD_CAP_REV10:
> +		port->negotiated_rev = PD_REV10;
> +		break;
> +	case PD_CAP_REV20:
> +		port->negotiated_rev = PD_REV20;
> +		break;
> +	case PD_CAP_REV30:
> +		port->negotiated_rev = PD_REV30;
> +		break;
> +	default:
> +		port->negotiated_rev = PD_MAX_REV;
> +		break;
> +	}
> +	port->negotiated_rev_prime = port->negotiated_rev;
> +}

Do we need this? Couldn't you just add one to rev_major?

        port->negotiated_rev = port->pd_rev.rev_major + 1;
        port->negotiated_rev_prime = port->pd_rev.rev_major + 1;

Or am I missing something?

thanks,

>  static void run_state_machine(struct tcpm_port *port)
>  {
>  	int ret;
> @@ -4782,8 +4805,7 @@ static void run_state_machine(struct tcpm_port *port)
>  		typec_set_pwr_opmode(port->typec_port, opmode);
>  		port->pwr_opmode = TYPEC_PWR_MODE_USB;
>  		port->caps_count = 0;
> -		port->negotiated_rev = PD_MAX_REV;
> -		port->negotiated_rev_prime = PD_MAX_REV;
> +		tcpm_set_initial_negotiated_rev(port);
>  		port->message_id = 0;
>  		port->message_id_prime = 0;
>  		port->rx_msgid = -1;
> @@ -5048,8 +5070,7 @@ static void run_state_machine(struct tcpm_port *port)
>  					      port->cc2 : port->cc1);
>  		typec_set_pwr_opmode(port->typec_port, opmode);
>  		port->pwr_opmode = TYPEC_PWR_MODE_USB;
> -		port->negotiated_rev = PD_MAX_REV;
> -		port->negotiated_rev_prime = PD_MAX_REV;
> +		tcpm_set_initial_negotiated_rev(port);
>  		port->message_id = 0;
>  		port->message_id_prime = 0;
>  		port->rx_msgid = -1;
> -- 
> 2.43.0

-- 
heikki

Re: [PATCH v2] usb: typec: tcpm: Use configured PD revision for negotiation

[Heikki Krogerus]

On Tue, May 13, 2025 at 04:39:09PM +0300, Heikki Krogerus wrote:
> On Tue, May 13, 2025 at 09:08:34PM +0800, Cosmo Chou wrote:
> > Initialize negotiated_rev and negotiated_rev_prime based on the port's
> > configured PD revision (rev_major) rather than always defaulting to
> > PD_MAX_REV. This ensures ports start PD communication using their
> > appropriate revision level.
> > 
> > This allows proper communication with devices that require specific
> > PD revision levels, especially for the hardware designed for PD 1.0
> > or 2.0 specifications.
> > 
> > Signed-off-by: Cosmo Chou <chou.cosmo@gmail.com>
> > ---
> > Change log:
> > 
> > v2:
> >   - Add PD_CAP_REVXX macros and use switch-case for better readability.
> > 
> > ---
> >  drivers/usb/typec/tcpm/tcpm.c | 29 +++++++++++++++++++++++++----
> >  1 file changed, 25 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> > index 8adf6f954633..48e9cfc2b49a 100644
> > --- a/drivers/usb/typec/tcpm/tcpm.c
> > +++ b/drivers/usb/typec/tcpm/tcpm.c
> > @@ -313,6 +313,10 @@ struct pd_data {
> >  	unsigned int operating_snk_mw;
> >  };
> >  
> > +#define PD_CAP_REV10	0x1
> > +#define PD_CAP_REV20	0x2
> > +#define PD_CAP_REV30	0x3
> > +
> >  struct pd_revision_info {
> >  	u8 rev_major;
> >  	u8 rev_minor;
> > @@ -4665,6 +4669,25 @@ static void tcpm_set_initial_svdm_version(struct tcpm_port *port)
> >  	}
> >  }
> >  
> > +static void tcpm_set_initial_negotiated_rev(struct tcpm_port *port)
> > +{
> > +	switch (port->pd_rev.rev_major) {
> > +	case PD_CAP_REV10:
> > +		port->negotiated_rev = PD_REV10;
> > +		break;
> > +	case PD_CAP_REV20:
> > +		port->negotiated_rev = PD_REV20;
> > +		break;
> > +	case PD_CAP_REV30:
> > +		port->negotiated_rev = PD_REV30;
> > +		break;
> > +	default:
> > +		port->negotiated_rev = PD_MAX_REV;
> > +		break;
> > +	}
> > +	port->negotiated_rev_prime = port->negotiated_rev;
> > +}
> 
> Do we need this? Couldn't you just add one to rev_major?
> 
>         port->negotiated_rev = port->pd_rev.rev_major + 1;
>         port->negotiated_rev_prime = port->pd_rev.rev_major + 1;
> 
> Or am I missing something?

Sorry, I mean minus one :-)

        port->negotiated_rev = port->pd_rev.rev_major - 1;
        port->negotiated_rev_prime = port->pd_rev.rev_major - 1;

-- 
heikki

Re: [PATCH v2] usb: typec: tcpm: Use configured PD revision for negotiation

[Cosmo Chou]

On Tue, May 13, 2025 at 04:50:49PM +0300, Heikki Krogerus wrote:
>
> On Tue, May 13, 2025 at 04:39:09PM +0300, Heikki Krogerus wrote:
> > On Tue, May 13, 2025 at 09:08:34PM +0800, Cosmo Chou wrote:
> > > Initialize negotiated_rev and negotiated_rev_prime based on the port's
> > > configured PD revision (rev_major) rather than always defaulting to
> > > PD_MAX_REV. This ensures ports start PD communication using their
> > > appropriate revision level.
> > >
> > > This allows proper communication with devices that require specific
> > > PD revision levels, especially for the hardware designed for PD 1.0
> > > or 2.0 specifications.
> > >
> > > Signed-off-by: Cosmo Chou <chou.cosmo@gmail.com>
> > > ---
> > > Change log:
> > >
> > > v2:
> > >   - Add PD_CAP_REVXX macros and use switch-case for better readability.
> > >
> > > ---
> > >  drivers/usb/typec/tcpm/tcpm.c | 29 +++++++++++++++++++++++++----
> > >  1 file changed, 25 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> > > index 8adf6f954633..48e9cfc2b49a 100644
> > > --- a/drivers/usb/typec/tcpm/tcpm.c
> > > +++ b/drivers/usb/typec/tcpm/tcpm.c
> > > @@ -313,6 +313,10 @@ struct pd_data {
> > >     unsigned int operating_snk_mw;
> > >  };
> > >
> > > +#define PD_CAP_REV10       0x1
> > > +#define PD_CAP_REV20       0x2
> > > +#define PD_CAP_REV30       0x3
> > > +
> > >  struct pd_revision_info {
> > >     u8 rev_major;
> > >     u8 rev_minor;
> > > @@ -4665,6 +4669,25 @@ static void tcpm_set_initial_svdm_version(struct tcpm_port *port)
> > >     }
> > >  }
> > >
> > > +static void tcpm_set_initial_negotiated_rev(struct tcpm_port *port)
> > > +{
> > > +   switch (port->pd_rev.rev_major) {
> > > +   case PD_CAP_REV10:
> > > +           port->negotiated_rev = PD_REV10;
> > > +           break;
> > > +   case PD_CAP_REV20:
> > > +           port->negotiated_rev = PD_REV20;
> > > +           break;
> > > +   case PD_CAP_REV30:
> > > +           port->negotiated_rev = PD_REV30;
> > > +           break;
> > > +   default:
> > > +           port->negotiated_rev = PD_MAX_REV;
> > > +           break;
> > > +   }
> > > +   port->negotiated_rev_prime = port->negotiated_rev;
> > > +}
> >
> > Do we need this? Couldn't you just add one to rev_major?
> >
> >         port->negotiated_rev = port->pd_rev.rev_major + 1;
> >         port->negotiated_rev_prime = port->pd_rev.rev_major + 1;
> >
> > Or am I missing something?
>
> Sorry, I mean minus one :-)
>
>         port->negotiated_rev = port->pd_rev.rev_major - 1;
>         port->negotiated_rev_prime = port->pd_rev.rev_major - 1;
>
> --
> heikki

It seems to be the PATCH v1:
https://lore.kernel.org/all/20250508174756.1300942-1-chou.cosmo@gmail.com/

if (port->pd_rev.rev_major > 0 && port->pd_rev.rev_major <= PD_MAX_REV + 1) {
        port->negotiated_rev = port->pd_rev.rev_major - 1;
        port->negotiated_rev_prime = port->pd_rev.rev_major - 1;
} else {
        port->negotiated_rev = PD_MAX_REV;
        port->negotiated_rev_prime = PD_MAX_REV;
}

--
Thanks
Cosmo

Re: [PATCH v2] usb: typec: tcpm: Use configured PD revision for negotiation

[Heikki Krogerus]

On Tue, May 13, 2025 at 10:14:32PM +0800, Cosmo Chou wrote:
> On Tue, May 13, 2025 at 04:50:49PM +0300, Heikki Krogerus wrote:
> >
> > On Tue, May 13, 2025 at 04:39:09PM +0300, Heikki Krogerus wrote:
> > > On Tue, May 13, 2025 at 09:08:34PM +0800, Cosmo Chou wrote:
> > > > Initialize negotiated_rev and negotiated_rev_prime based on the port's
> > > > configured PD revision (rev_major) rather than always defaulting to
> > > > PD_MAX_REV. This ensures ports start PD communication using their
> > > > appropriate revision level.
> > > >
> > > > This allows proper communication with devices that require specific
> > > > PD revision levels, especially for the hardware designed for PD 1.0
> > > > or 2.0 specifications.
> > > >
> > > > Signed-off-by: Cosmo Chou <chou.cosmo@gmail.com>
> > > > ---
> > > > Change log:
> > > >
> > > > v2:
> > > >   - Add PD_CAP_REVXX macros and use switch-case for better readability.
> > > >
> > > > ---
> > > >  drivers/usb/typec/tcpm/tcpm.c | 29 +++++++++++++++++++++++++----
> > > >  1 file changed, 25 insertions(+), 4 deletions(-)
> > > >
> > > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> > > > index 8adf6f954633..48e9cfc2b49a 100644
> > > > --- a/drivers/usb/typec/tcpm/tcpm.c
> > > > +++ b/drivers/usb/typec/tcpm/tcpm.c
> > > > @@ -313,6 +313,10 @@ struct pd_data {
> > > >     unsigned int operating_snk_mw;
> > > >  };
> > > >
> > > > +#define PD_CAP_REV10       0x1
> > > > +#define PD_CAP_REV20       0x2
> > > > +#define PD_CAP_REV30       0x3
> > > > +
> > > >  struct pd_revision_info {
> > > >     u8 rev_major;
> > > >     u8 rev_minor;
> > > > @@ -4665,6 +4669,25 @@ static void tcpm_set_initial_svdm_version(struct tcpm_port *port)
> > > >     }
> > > >  }
> > > >
> > > > +static void tcpm_set_initial_negotiated_rev(struct tcpm_port *port)
> > > > +{
> > > > +   switch (port->pd_rev.rev_major) {
> > > > +   case PD_CAP_REV10:
> > > > +           port->negotiated_rev = PD_REV10;
> > > > +           break;
> > > > +   case PD_CAP_REV20:
> > > > +           port->negotiated_rev = PD_REV20;
> > > > +           break;
> > > > +   case PD_CAP_REV30:
> > > > +           port->negotiated_rev = PD_REV30;
> > > > +           break;
> > > > +   default:
> > > > +           port->negotiated_rev = PD_MAX_REV;
> > > > +           break;
> > > > +   }
> > > > +   port->negotiated_rev_prime = port->negotiated_rev;
> > > > +}
> > >
> > > Do we need this? Couldn't you just add one to rev_major?
> > >
> > >         port->negotiated_rev = port->pd_rev.rev_major + 1;
> > >         port->negotiated_rev_prime = port->pd_rev.rev_major + 1;
> > >
> > > Or am I missing something?
> >
> > Sorry, I mean minus one :-)
> >
> >         port->negotiated_rev = port->pd_rev.rev_major - 1;
> >         port->negotiated_rev_prime = port->pd_rev.rev_major - 1;
> >
> > --
> > heikki
> 
> It seems to be the PATCH v1:
> https://lore.kernel.org/all/20250508174756.1300942-1-chou.cosmo@gmail.com/
> 
> if (port->pd_rev.rev_major > 0 && port->pd_rev.rev_major <= PD_MAX_REV + 1) {
>         port->negotiated_rev = port->pd_rev.rev_major - 1;
>         port->negotiated_rev_prime = port->pd_rev.rev_major - 1;
> } else {
>         port->negotiated_rev = PD_MAX_REV;
>         port->negotiated_rev_prime = PD_MAX_REV;
> }

Okay, sorry I missed that. I still don't like the extra definitions,
but I don't have any better idea (I guess macro is not an option?).

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

thanks,

-- 
heikki

Re: [PATCH v2] usb: typec: tcpm: Use configured PD revision for negotiation

[Amit Sunil Dhamne]

Hi Heikki,

On 5/14/25 1:12 AM, Heikki Krogerus wrote:
> On Tue, May 13, 2025 at 10:14:32PM +0800, Cosmo Chou wrote:
>> On Tue, May 13, 2025 at 04:50:49PM +0300, Heikki Krogerus wrote:
>>> On Tue, May 13, 2025 at 04:39:09PM +0300, Heikki Krogerus wrote:
>>>> On Tue, May 13, 2025 at 09:08:34PM +0800, Cosmo Chou wrote:
>>>>> Initialize negotiated_rev and negotiated_rev_prime based on the port's
>>>>> configured PD revision (rev_major) rather than always defaulting to
>>>>> PD_MAX_REV. This ensures ports start PD communication using their
>>>>> appropriate revision level.
>>>>>
>>>>> This allows proper communication with devices that require specific
>>>>> PD revision levels, especially for the hardware designed for PD 1.0
>>>>> or 2.0 specifications.
>>>>>
>>>>> Signed-off-by: Cosmo Chou <chou.cosmo@gmail.com>
>>>>> ---
>>>>> Change log:
>>>>>
>>>>> v2:
>>>>>   - Add PD_CAP_REVXX macros and use switch-case for better readability.
>>>>>
>>>>> ---
>>>>>  drivers/usb/typec/tcpm/tcpm.c | 29 +++++++++++++++++++++++++----
>>>>>  1 file changed, 25 insertions(+), 4 deletions(-)
>>>>>
>>>>> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
>>>>> index 8adf6f954633..48e9cfc2b49a 100644
>>>>> --- a/drivers/usb/typec/tcpm/tcpm.c
>>>>> +++ b/drivers/usb/typec/tcpm/tcpm.c
>>>>> @@ -313,6 +313,10 @@ struct pd_data {
>>>>>     unsigned int operating_snk_mw;
>>>>>  };
>>>>>
>>>>> +#define PD_CAP_REV10       0x1
>>>>> +#define PD_CAP_REV20       0x2
>>>>> +#define PD_CAP_REV30       0x3
>>>>> +
>>>>>  struct pd_revision_info {
>>>>>     u8 rev_major;
>>>>>     u8 rev_minor;
>>>>> @@ -4665,6 +4669,25 @@ static void tcpm_set_initial_svdm_version(struct tcpm_port *port)
>>>>>     }
>>>>>  }
>>>>>
>>>>> +static void tcpm_set_initial_negotiated_rev(struct tcpm_port *port)
>>>>> +{
>>>>> +   switch (port->pd_rev.rev_major) {
>>>>> +   case PD_CAP_REV10:
>>>>> +           port->negotiated_rev = PD_REV10;
>>>>> +           break;
>>>>> +   case PD_CAP_REV20:
>>>>> +           port->negotiated_rev = PD_REV20;
>>>>> +           break;
>>>>> +   case PD_CAP_REV30:
>>>>> +           port->negotiated_rev = PD_REV30;
>>>>> +           break;
>>>>> +   default:
>>>>> +           port->negotiated_rev = PD_MAX_REV;
>>>>> +           break;
>>>>> +   }
>>>>> +   port->negotiated_rev_prime = port->negotiated_rev;
>>>>> +}
>>>> Do we need this? Couldn't you just add one to rev_major?
>>>>
>>>>         port->negotiated_rev = port->pd_rev.rev_major + 1;
>>>>         port->negotiated_rev_prime = port->pd_rev.rev_major + 1;
>>>>
>>>> Or am I missing something?
>>> Sorry, I mean minus one :-)
>>>
>>>         port->negotiated_rev = port->pd_rev.rev_major - 1;
>>>         port->negotiated_rev_prime = port->pd_rev.rev_major - 1;

The only reason I asked for macros is that in the case of Spec Revision
for header, the value for PD 3.0 is 0x2, PD 2.0 is 0x1 & so on. While
for PD max revisions, it's the exact values. Having a clear distinction
may be easier to follow. If you want to go with the +/- approach you can
add a comment stating the above. 

I don't have a hard opinion on either approach :).

Thanks,

Amit

>>>
>>> --
>>> heikki
>> It seems to be the PATCH v1:
>> https://lore.kernel.org/all/20250508174756.1300942-1-chou.cosmo@gmail.com/
>>
>> if (port->pd_rev.rev_major > 0 && port->pd_rev.rev_major <= PD_MAX_REV + 1) {
>>         port->negotiated_rev = port->pd_rev.rev_major - 1;
>>         port->negotiated_rev_prime = port->pd_rev.rev_major - 1;
>> } else {
>>         port->negotiated_rev = PD_MAX_REV;
>>         port->negotiated_rev_prime = PD_MAX_REV;
>> }
> Okay, sorry I missed that. I still don't like the extra definitions,
> but I don't have any better idea (I guess macro is not an option?).
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
>
> thanks,
>

Re: [PATCH v2] usb: typec: tcpm: Use configured PD revision for negotiation

[Badhri Jagan Sridharan]

On Thu, May 15, 2025 at 12:15 AM Amit Sunil Dhamne <amitsd@google.com> wrote:
>
> Hi Heikki,
>
> On 5/14/25 1:12 AM, Heikki Krogerus wrote:
> > On Tue, May 13, 2025 at 10:14:32PM +0800, Cosmo Chou wrote:
> >> On Tue, May 13, 2025 at 04:50:49PM +0300, Heikki Krogerus wrote:
> >>> On Tue, May 13, 2025 at 04:39:09PM +0300, Heikki Krogerus wrote:
> >>>> On Tue, May 13, 2025 at 09:08:34PM +0800, Cosmo Chou wrote:
> >>>>> Initialize negotiated_rev and negotiated_rev_prime based on the port's
> >>>>> configured PD revision (rev_major) rather than always defaulting to
> >>>>> PD_MAX_REV. This ensures ports start PD communication using their
> >>>>> appropriate revision level.
> >>>>>
> >>>>> This allows proper communication with devices that require specific
> >>>>> PD revision levels, especially for the hardware designed for PD 1.0
> >>>>> or 2.0 specifications.
> >>>>>
> >>>>> Signed-off-by: Cosmo Chou <chou.cosmo@gmail.com>

Reviewed-by: Badhri Jagan Sridharan <badhri@google.com>

> >>>>> ---
> >>>>> Change log:
> >>>>>
> >>>>> v2:
> >>>>>   - Add PD_CAP_REVXX macros and use switch-case for better readability.
> >>>>>
> >>>>> ---
> >>>>>  drivers/usb/typec/tcpm/tcpm.c | 29 +++++++++++++++++++++++++----
> >>>>>  1 file changed, 25 insertions(+), 4 deletions(-)
> >>>>>
> >>>>> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> >>>>> index 8adf6f954633..48e9cfc2b49a 100644
> >>>>> --- a/drivers/usb/typec/tcpm/tcpm.c
> >>>>> +++ b/drivers/usb/typec/tcpm/tcpm.c
> >>>>> @@ -313,6 +313,10 @@ struct pd_data {
> >>>>>     unsigned int operating_snk_mw;
> >>>>>  };
> >>>>>
> >>>>> +#define PD_CAP_REV10       0x1
> >>>>> +#define PD_CAP_REV20       0x2
> >>>>> +#define PD_CAP_REV30       0x3
> >>>>> +
> >>>>>  struct pd_revision_info {
> >>>>>     u8 rev_major;
> >>>>>     u8 rev_minor;
> >>>>> @@ -4665,6 +4669,25 @@ static void tcpm_set_initial_svdm_version(struct tcpm_port *port)
> >>>>>     }
> >>>>>  }
> >>>>>
> >>>>> +static void tcpm_set_initial_negotiated_rev(struct tcpm_port *port)
> >>>>> +{
> >>>>> +   switch (port->pd_rev.rev_major) {
> >>>>> +   case PD_CAP_REV10:
> >>>>> +           port->negotiated_rev = PD_REV10;
> >>>>> +           break;
> >>>>> +   case PD_CAP_REV20:
> >>>>> +           port->negotiated_rev = PD_REV20;
> >>>>> +           break;
> >>>>> +   case PD_CAP_REV30:
> >>>>> +           port->negotiated_rev = PD_REV30;
> >>>>> +           break;
> >>>>> +   default:
> >>>>> +           port->negotiated_rev = PD_MAX_REV;
> >>>>> +           break;
> >>>>> +   }
> >>>>> +   port->negotiated_rev_prime = port->negotiated_rev;
> >>>>> +}

IMHO this looks better in terms of readability although V1 is more concise.

Thanks,
Badhri

> >>>> Do we need this? Couldn't you just add one to rev_major?
> >>>>
> >>>>         port->negotiated_rev = port->pd_rev.rev_major + 1;
> >>>>         port->negotiated_rev_prime = port->pd_rev.rev_major + 1;
> >>>>
> >>>> Or am I missing something?
> >>> Sorry, I mean minus one :-)
> >>>
> >>>         port->negotiated_rev = port->pd_rev.rev_major - 1;
> >>>         port->negotiated_rev_prime = port->pd_rev.rev_major - 1;
>
> The only reason I asked for macros is that in the case of Spec Revision
> for header, the value for PD 3.0 is 0x2, PD 2.0 is 0x1 & so on. While
> for PD max revisions, it's the exact values. Having a clear distinction
> may be easier to follow. If you want to go with the +/- approach you can
> add a comment stating the above.
>
> I don't have a hard opinion on either approach :).
>
> Thanks,
>
> Amit
>
> >>>
> >>> --
> >>> heikki
> >> It seems to be the PATCH v1:
> >> https://lore.kernel.org/all/20250508174756.1300942-1-chou.cosmo@gmail.com/
> >>
> >> if (port->pd_rev.rev_major > 0 && port->pd_rev.rev_major <= PD_MAX_REV + 1) {
> >>         port->negotiated_rev = port->pd_rev.rev_major - 1;
> >>         port->negotiated_rev_prime = port->pd_rev.rev_major - 1
> >> } else {
> >>         port->negotiated_rev = PD_MAX_REV;
> >>         port->negotiated_rev_prime = PD_MAX_REV;
> >> }
> > Okay, sorry I missed that. I still don't like the extra definitions,
> > but I don't have any better idea (I guess macro is not an option?).
> > Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> >
> > thanks,
> >