[v9,2/3] usb: typec: tcpci: Add callback for evaluating contaminant presence

Message ID 20221210061626.948426-2-badhri@google.com
State New
Headers
Series [v9,1/3] usb: typec: tcpm: Add callbacks to mitigate wakeups due to contaminant |

Commit Message

Badhri Jagan Sridharan Dec. 10, 2022, 6:16 a.m. UTC
  This change adds callback to evaluate presence of contaminant in
the TCPCI layer.

Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
---
Changes since v7:
* None. Skipped versions by mistake.
Changes since v6:
* Removed is_potential_contaminant callback
Changes since v5:
* None
Changes since v4:
* None
Changes since v3:
* None
Changes since v2:
* Added tcpci_is_potential_contaminant to offload
* disconnect_while_debounce logic
---
 drivers/usb/typec/tcpm/tcpci.c | 9 +++++++++
 include/linux/usb/tcpci.h      | 7 +++++++
 2 files changed, 16 insertions(+)
  

Comments

Guenter Roeck Dec. 10, 2022, 4:07 p.m. UTC | #1
On 12/9/22 22:16, Badhri Jagan Sridharan wrote:
> This change adds callback to evaluate presence of contaminant in
> the TCPCI layer.
> 
> Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
> ---
> Changes since v7:
> * None. Skipped versions by mistake.
> Changes since v6:
> * Removed is_potential_contaminant callback
> Changes since v5:
> * None
> Changes since v4:
> * None
> Changes since v3:
> * None
> Changes since v2:
> * Added tcpci_is_potential_contaminant to offload
> * disconnect_while_debounce logic
> ---
>   drivers/usb/typec/tcpm/tcpci.c | 9 +++++++++
>   include/linux/usb/tcpci.h      | 7 +++++++
>   2 files changed, 16 insertions(+)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index fe781a38dc82..c8e78c13c9c4 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -403,6 +403,14 @@ static void tcpci_frs_sourcing_vbus(struct tcpc_dev *dev)
>   		tcpci->data->frs_sourcing_vbus(tcpci, tcpci->data);
>   }
>   
> +static void tcpci_check_contaminant(struct tcpc_dev *dev)
> +{
> +	struct tcpci *tcpci = tcpc_to_tcpci(dev);
> +
> +	if (tcpci->data->check_contaminant)
> +		tcpci->data->check_contaminant(tcpci, tcpci->data);
> +}
> +

With this callback to tcpm in place, how does tcpm ever leave the
CHECK_CONTAMINANT state if the low level driver does not support
the callback ?

Thanks,
Guenter


>   static int tcpci_set_bist_data(struct tcpc_dev *tcpc, bool enable)
>   {
>   	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
> @@ -777,6 +785,7 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
>   	tcpci->tcpc.enable_frs = tcpci_enable_frs;
>   	tcpci->tcpc.frs_sourcing_vbus = tcpci_frs_sourcing_vbus;
>   	tcpci->tcpc.set_partner_usb_comm_capable = tcpci_set_partner_usb_comm_capable;
> +	tcpci->tcpc.check_contaminant = tcpci_check_contaminant;
>   
>   	if (tcpci->data->auto_discharge_disconnect) {
>   		tcpci->tcpc.enable_auto_vbus_discharge = tcpci_enable_auto_vbus_discharge;
> diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
> index 17657451c762..85e95a3251d3 100644
> --- a/include/linux/usb/tcpci.h
> +++ b/include/linux/usb/tcpci.h
> @@ -188,6 +188,12 @@ struct tcpci;
>    *		Optional; The USB Communications Capable bit indicates if port
>    *		partner is capable of communication over the USB data lines
>    *		(e.g. D+/- or SS Tx/Rx). Called to notify the status of the bit.
> + * @check_contaminant:
> + *		Optional; The callback is invoked when chiplevel drivers indicated
> + *		that the USB port needs to be checked for contaminant presence.
> + *		Chip level drivers are expected to check for contaminant and call
> + *		tcpm_clean_port when the port is clean to put the port back into
> + *		toggling state.
>    */
>   struct tcpci_data {
>   	struct regmap *regmap;
> @@ -204,6 +210,7 @@ struct tcpci_data {
>   	void (*frs_sourcing_vbus)(struct tcpci *tcpci, struct tcpci_data *data);
>   	void (*set_partner_usb_comm_capable)(struct tcpci *tcpci, struct tcpci_data *data,
>   					     bool capable);
> +	void (*check_contaminant)(struct tcpci *tcpci, struct tcpci_data *data);
>   };
>   
>   struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data);
  
Badhri Jagan Sridharan Dec. 10, 2022, 5:36 p.m. UTC | #2
On Sat, Dec 10, 2022 at 8:08 AM Guenter Roeck <linux@roeck-us.net> wrote:
>
> On 12/9/22 22:16, Badhri Jagan Sridharan wrote:
> > This change adds callback to evaluate presence of contaminant in
> > the TCPCI layer.
> >
> > Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
> > ---
> > Changes since v7:
> > * None. Skipped versions by mistake.
> > Changes since v6:
> > * Removed is_potential_contaminant callback
> > Changes since v5:
> > * None
> > Changes since v4:
> > * None
> > Changes since v3:
> > * None
> > Changes since v2:
> > * Added tcpci_is_potential_contaminant to offload
> > * disconnect_while_debounce logic
> > ---
> >   drivers/usb/typec/tcpm/tcpci.c | 9 +++++++++
> >   include/linux/usb/tcpci.h      | 7 +++++++
> >   2 files changed, 16 insertions(+)
> >
> > diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> > index fe781a38dc82..c8e78c13c9c4 100644
> > --- a/drivers/usb/typec/tcpm/tcpci.c
> > +++ b/drivers/usb/typec/tcpm/tcpci.c
> > @@ -403,6 +403,14 @@ static void tcpci_frs_sourcing_vbus(struct tcpc_dev *dev)
> >               tcpci->data->frs_sourcing_vbus(tcpci, tcpci->data);
> >   }
> >
> > +static void tcpci_check_contaminant(struct tcpc_dev *dev)
> > +{
> > +     struct tcpci *tcpci = tcpc_to_tcpci(dev);
> > +
> > +     if (tcpci->data->check_contaminant)
> > +             tcpci->data->check_contaminant(tcpci, tcpci->data);
> > +}
> > +
>
> With this callback to tcpm in place, how does tcpm ever leave the
> CHECK_CONTAMINANT state if the low level driver does not support
> the callback ?

Ah ! Good point.. I will fix it by installing the callback only when
the lower level driver implements check_contaminant.
Let me know if you think it wouldn't work.

--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -785,7 +785,9 @@ struct tcpci *tcpci_register_port(struct device
*dev, struct tcpci_data *data)
        tcpci->tcpc.enable_frs = tcpci_enable_frs;
        tcpci->tcpc.frs_sourcing_vbus = tcpci_frs_sourcing_vbus;
        tcpci->tcpc.set_partner_usb_comm_capable =
tcpci_set_partner_usb_comm_capable;
-       tcpci->tcpc.check_contaminant = tcpci_check_contaminant;
+
+       if (tcpci->data->check_contaminant)
+               tcpci->tcpc.check_contaminant = tcpci_check_contaminant;

Thanks,
Badhri

>
> Thanks,
> Guenter
>
>
> >   static int tcpci_set_bist_data(struct tcpc_dev *tcpc, bool enable)
> >   {
> >       struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
> > @@ -777,6 +785,7 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
> >       tcpci->tcpc.enable_frs = tcpci_enable_frs;
> >       tcpci->tcpc.frs_sourcing_vbus = tcpci_frs_sourcing_vbus;
> >       tcpci->tcpc.set_partner_usb_comm_capable = tcpci_set_partner_usb_comm_capable;
> > +     tcpci->tcpc.check_contaminant = tcpci_check_contaminant;
> >
> >       if (tcpci->data->auto_discharge_disconnect) {
> >               tcpci->tcpc.enable_auto_vbus_discharge = tcpci_enable_auto_vbus_discharge;
> > diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
> > index 17657451c762..85e95a3251d3 100644
> > --- a/include/linux/usb/tcpci.h
> > +++ b/include/linux/usb/tcpci.h
> > @@ -188,6 +188,12 @@ struct tcpci;
> >    *          Optional; The USB Communications Capable bit indicates if port
> >    *          partner is capable of communication over the USB data lines
> >    *          (e.g. D+/- or SS Tx/Rx). Called to notify the status of the bit.
> > + * @check_contaminant:
> > + *           Optional; The callback is invoked when chiplevel drivers indicated
> > + *           that the USB port needs to be checked for contaminant presence.
> > + *           Chip level drivers are expected to check for contaminant and call
> > + *           tcpm_clean_port when the port is clean to put the port back into
> > + *           toggling state.
> >    */
> >   struct tcpci_data {
> >       struct regmap *regmap;
> > @@ -204,6 +210,7 @@ struct tcpci_data {
> >       void (*frs_sourcing_vbus)(struct tcpci *tcpci, struct tcpci_data *data);
> >       void (*set_partner_usb_comm_capable)(struct tcpci *tcpci, struct tcpci_data *data,
> >                                            bool capable);
> > +     void (*check_contaminant)(struct tcpci *tcpci, struct tcpci_data *data);
> >   };
> >
> >   struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data);
>
  

Patch

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index fe781a38dc82..c8e78c13c9c4 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -403,6 +403,14 @@  static void tcpci_frs_sourcing_vbus(struct tcpc_dev *dev)
 		tcpci->data->frs_sourcing_vbus(tcpci, tcpci->data);
 }
 
+static void tcpci_check_contaminant(struct tcpc_dev *dev)
+{
+	struct tcpci *tcpci = tcpc_to_tcpci(dev);
+
+	if (tcpci->data->check_contaminant)
+		tcpci->data->check_contaminant(tcpci, tcpci->data);
+}
+
 static int tcpci_set_bist_data(struct tcpc_dev *tcpc, bool enable)
 {
 	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
@@ -777,6 +785,7 @@  struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
 	tcpci->tcpc.enable_frs = tcpci_enable_frs;
 	tcpci->tcpc.frs_sourcing_vbus = tcpci_frs_sourcing_vbus;
 	tcpci->tcpc.set_partner_usb_comm_capable = tcpci_set_partner_usb_comm_capable;
+	tcpci->tcpc.check_contaminant = tcpci_check_contaminant;
 
 	if (tcpci->data->auto_discharge_disconnect) {
 		tcpci->tcpc.enable_auto_vbus_discharge = tcpci_enable_auto_vbus_discharge;
diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
index 17657451c762..85e95a3251d3 100644
--- a/include/linux/usb/tcpci.h
+++ b/include/linux/usb/tcpci.h
@@ -188,6 +188,12 @@  struct tcpci;
  *		Optional; The USB Communications Capable bit indicates if port
  *		partner is capable of communication over the USB data lines
  *		(e.g. D+/- or SS Tx/Rx). Called to notify the status of the bit.
+ * @check_contaminant:
+ *		Optional; The callback is invoked when chiplevel drivers indicated
+ *		that the USB port needs to be checked for contaminant presence.
+ *		Chip level drivers are expected to check for contaminant and call
+ *		tcpm_clean_port when the port is clean to put the port back into
+ *		toggling state.
  */
 struct tcpci_data {
 	struct regmap *regmap;
@@ -204,6 +210,7 @@  struct tcpci_data {
 	void (*frs_sourcing_vbus)(struct tcpci *tcpci, struct tcpci_data *data);
 	void (*set_partner_usb_comm_capable)(struct tcpci *tcpci, struct tcpci_data *data,
 					     bool capable);
+	void (*check_contaminant)(struct tcpci *tcpci, struct tcpci_data *data);
 };
 
 struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data);