[v3] Thunderbolt and DP altmode support for cros-ec-typec

[PATCH v3 6/7] platform/chrome: cros_ec_typec: Thunderbolt support

Posted by Abhishek Pandit-Subedi 2 weeks, 2 days ago

Add support for entering and exiting Thunderbolt alt-mode using AP
driven alt-mode.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v3:
- Fix usage of TBT sid and mode.
- Removed unused vdm operations during altmode registration

Changes in v2:
- Refactored thunderbolt support into cros_typec_altmode.c

 drivers/platform/chrome/Makefile             |  3 +
 drivers/platform/chrome/cros_ec_typec.c      | 23 +++---
 drivers/platform/chrome/cros_typec_altmode.c | 85 ++++++++++++++++++++
 drivers/platform/chrome/cros_typec_altmode.h | 14 ++++
 4 files changed, 114 insertions(+), 11 deletions(-)

diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index 2f90d4db8099..b9b1281de063 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -21,6 +21,9 @@ cros-ec-typec-objs			:= cros_ec_typec.o cros_typec_vdm.o
 ifneq ($(CONFIG_TYPEC_DP_ALTMODE),)
 	cros-ec-typec-objs		+= cros_typec_altmode.o
 endif
+ifneq ($(CONFIG_TYPEC_TBT_ALTMODE),)
+	cros-ec-typec-objs		+= cros_typec_altmode.o
+endif
 obj-$(CONFIG_CROS_EC_TYPEC)		+= cros-ec-typec.o
 
 obj-$(CONFIG_CROS_EC_LPC)		+= cros_ec_lpcs.o
diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 3a6f5f2717b9..558b618df63c 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -302,18 +302,19 @@ static int cros_typec_register_port_altmodes(struct cros_typec_data *typec,
 
 	/*
 	 * Register TBT compatibility alt mode. The EC will not enter the mode
-	 * if it doesn't support it, so it's safe to register it unconditionally
-	 * here for now.
+	 * if it doesn't support it and it will not enter automatically by
+	 * design so we can use the |ap_driven_altmode| feature to check if we
+	 * should register it.
 	 */
-	memset(&desc, 0, sizeof(desc));
-	desc.svid = USB_TYPEC_TBT_SID;
-	desc.mode = TYPEC_ANY_MODE;
-	amode = typec_port_register_altmode(port->port, &desc);
-	if (IS_ERR(amode))
-		return PTR_ERR(amode);
-	port->port_altmode[CROS_EC_ALTMODE_TBT] = amode;
-	typec_altmode_set_drvdata(amode, port);
-	amode->ops = &port_amode_ops;
+	if (typec->ap_driven_altmode) {
+		memset(&desc, 0, sizeof(desc));
+		desc.svid = USB_TYPEC_TBT_SID;
+		desc.mode = TBT_MODE;
+		amode = cros_typec_register_thunderbolt(port, &desc);
+		if (IS_ERR(amode))
+			return PTR_ERR(amode);
+		port->port_altmode[CROS_EC_ALTMODE_TBT] = amode;
+	}
 
 	port->state.alt = NULL;
 	port->state.mode = TYPEC_STATE_USB;
diff --git a/drivers/platform/chrome/cros_typec_altmode.c b/drivers/platform/chrome/cros_typec_altmode.c
index 3598b8a6ceee..9cf2cef6c277 100644
--- a/drivers/platform/chrome/cros_typec_altmode.c
+++ b/drivers/platform/chrome/cros_typec_altmode.c
@@ -8,6 +8,7 @@
 #include "cros_ec_typec.h"
 
 #include <linux/usb/typec_dp.h>
+#include <linux/usb/typec_tbt.h>
 #include <linux/usb/pd_vdo.h>
 
 #include "cros_typec_altmode.h"
@@ -67,6 +68,8 @@ static int cros_typec_altmode_enter(struct typec_altmode *alt, u32 *vdo)
 
 	if (data->sid == USB_TYPEC_DP_SID)
 		req.mode_to_enter = CROS_EC_ALTMODE_DP;
+	else if (data->sid == USB_TYPEC_TBT_SID)
+		req.mode_to_enter = CROS_EC_ALTMODE_TBT;
 	else
 		return -EOPNOTSUPP;
 
@@ -196,6 +199,53 @@ static int cros_typec_displayport_vdm(struct typec_altmode *alt, u32 header,
 	return 0;
 }
 
+static int cros_typec_thunderbolt_vdm(struct typec_altmode *alt, u32 header,
+				      const u32 *data, int count)
+{
+	struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
+
+	int cmd_type = PD_VDO_CMDT(header);
+	int cmd = PD_VDO_CMD(header);
+	int svdm_version;
+
+	svdm_version = typec_altmode_get_svdm_version(alt);
+	if (svdm_version < 0)
+		return svdm_version;
+
+	switch (cmd_type) {
+	case CMDT_INIT:
+		if (PD_VDO_SVDM_VER(header) < svdm_version) {
+			typec_partner_set_svdm_version(adata->port->partner,
+						       PD_VDO_SVDM_VER(header));
+			svdm_version = PD_VDO_SVDM_VER(header);
+		}
+
+		adata->header = VDO(adata->sid, 1, svdm_version, cmd);
+		adata->header |= VDO_OPOS(adata->mode);
+
+		switch (cmd) {
+		case CMD_ENTER_MODE:
+			/* Don't respond to the enter mode vdm because it
+			 * triggers mux configuration. This is handled directly
+			 * by the cros_ec_typec driver so the Thunderbolt driver
+			 * doesn't need to be involved.
+			 */
+			break;
+		default:
+			adata->header |= VDO_CMDT(CMDT_RSP_ACK);
+			schedule_work(&adata->work);
+			break;
+		}
+
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+
 static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
 				      const u32 *data, int count)
 {
@@ -204,6 +254,9 @@ static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
 	if (adata->sid == USB_TYPEC_DP_SID)
 		return cros_typec_displayport_vdm(alt, header, data, count);
 
+	if (adata->sid == USB_TYPEC_TBT_SID)
+		return cros_typec_thunderbolt_vdm(alt, header, data, count);
+
 	return -EINVAL;
 }
 
@@ -273,3 +326,35 @@ cros_typec_register_displayport(struct cros_typec_port *port,
 	return alt;
 }
 #endif
+
+#if IS_ENABLED(CONFIG_TYPEC_TBT_ALTMODE)
+struct typec_altmode *
+cros_typec_register_thunderbolt(struct cros_typec_port *port,
+				struct typec_altmode_desc *desc)
+{
+	struct typec_altmode *alt;
+	struct cros_typec_altmode_data *data;
+
+	alt = typec_port_register_altmode(port->port, desc);
+	if (IS_ERR(alt))
+		return alt;
+
+	data = devm_kzalloc(&alt->dev, sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		typec_unregister_altmode(alt);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	INIT_WORK(&data->work, cros_typec_altmode_work);
+	data->alt = alt;
+	data->port = port;
+	data->ap_mode_entry = true;
+	data->sid = desc->svid;
+	data->mode = desc->mode;
+
+	typec_altmode_set_ops(alt, &cros_typec_altmode_ops);
+	typec_altmode_set_drvdata(alt, data);
+
+	return alt;
+}
+#endif
diff --git a/drivers/platform/chrome/cros_typec_altmode.h b/drivers/platform/chrome/cros_typec_altmode.h
index c6f8fb02c99c..810b553ddcd8 100644
--- a/drivers/platform/chrome/cros_typec_altmode.h
+++ b/drivers/platform/chrome/cros_typec_altmode.h
@@ -31,4 +31,18 @@ static inline int cros_typec_displayport_status_update(struct typec_altmode *alt
 	return 0;
 }
 #endif
+
+#if IS_ENABLED(CONFIG_TYPEC_TBT_ALTMODE)
+struct typec_altmode *
+cros_typec_register_thunderbolt(struct cros_typec_port *port,
+				struct typec_altmode_desc *desc);
+#else
+static inline struct typec_altmode *
+cros_typec_register_thunderbolt(struct cros_typec_port *port,
+				struct typec_altmode_desc *desc)
+{
+	return typec_port_register_altmode(port->port, desc);
+}
+#endif
+
 #endif /* __CROS_TYPEC_ALTMODE_H__ */
-- 
2.47.0.277.g8800431eea-goog

Re: [PATCH v3 6/7] platform/chrome: cros_ec_typec: Thunderbolt support

Posted by Dmitry Baryshkov 2 weeks ago

On Thu, Nov 07, 2024 at 11:29:59AM -0800, Abhishek Pandit-Subedi wrote:
> Add support for entering and exiting Thunderbolt alt-mode using AP
> driven alt-mode.
> 
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> ---
> 
> Changes in v3:
> - Fix usage of TBT sid and mode.
> - Removed unused vdm operations during altmode registration
> 
> Changes in v2:
> - Refactored thunderbolt support into cros_typec_altmode.c
> 
>  drivers/platform/chrome/Makefile             |  3 +
>  drivers/platform/chrome/cros_ec_typec.c      | 23 +++---
>  drivers/platform/chrome/cros_typec_altmode.c | 85 ++++++++++++++++++++
>  drivers/platform/chrome/cros_typec_altmode.h | 14 ++++
>  4 files changed, 114 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
> index 2f90d4db8099..b9b1281de063 100644
> --- a/drivers/platform/chrome/Makefile
> +++ b/drivers/platform/chrome/Makefile
> @@ -21,6 +21,9 @@ cros-ec-typec-objs			:= cros_ec_typec.o cros_typec_vdm.o
>  ifneq ($(CONFIG_TYPEC_DP_ALTMODE),)
>  	cros-ec-typec-objs		+= cros_typec_altmode.o
>  endif
> +ifneq ($(CONFIG_TYPEC_TBT_ALTMODE),)
> +	cros-ec-typec-objs		+= cros_typec_altmode.o
> +endif

Doesn't this also result in the object file being included twice and
thus in a duplicate symbols declaration?

>  obj-$(CONFIG_CROS_EC_TYPEC)		+= cros-ec-typec.o
>  
>  obj-$(CONFIG_CROS_EC_LPC)		+= cros_ec_lpcs.o
> diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
> index 3a6f5f2717b9..558b618df63c 100644
> --- a/drivers/platform/chrome/cros_ec_typec.c
> +++ b/drivers/platform/chrome/cros_ec_typec.c
> @@ -302,18 +302,19 @@ static int cros_typec_register_port_altmodes(struct cros_typec_data *typec,
>  
>  	/*
>  	 * Register TBT compatibility alt mode. The EC will not enter the mode
> -	 * if it doesn't support it, so it's safe to register it unconditionally
> -	 * here for now.
> +	 * if it doesn't support it and it will not enter automatically by
> +	 * design so we can use the |ap_driven_altmode| feature to check if we
> +	 * should register it.
>  	 */
> -	memset(&desc, 0, sizeof(desc));
> -	desc.svid = USB_TYPEC_TBT_SID;
> -	desc.mode = TYPEC_ANY_MODE;
> -	amode = typec_port_register_altmode(port->port, &desc);
> -	if (IS_ERR(amode))
> -		return PTR_ERR(amode);
> -	port->port_altmode[CROS_EC_ALTMODE_TBT] = amode;
> -	typec_altmode_set_drvdata(amode, port);
> -	amode->ops = &port_amode_ops;
> +	if (typec->ap_driven_altmode) {
> +		memset(&desc, 0, sizeof(desc));
> +		desc.svid = USB_TYPEC_TBT_SID;
> +		desc.mode = TBT_MODE;
> +		amode = cros_typec_register_thunderbolt(port, &desc);
> +		if (IS_ERR(amode))
> +			return PTR_ERR(amode);
> +		port->port_altmode[CROS_EC_ALTMODE_TBT] = amode;
> +	}
>  
>  	port->state.alt = NULL;
>  	port->state.mode = TYPEC_STATE_USB;
> diff --git a/drivers/platform/chrome/cros_typec_altmode.c b/drivers/platform/chrome/cros_typec_altmode.c
> index 3598b8a6ceee..9cf2cef6c277 100644
> --- a/drivers/platform/chrome/cros_typec_altmode.c
> +++ b/drivers/platform/chrome/cros_typec_altmode.c
> @@ -8,6 +8,7 @@
>  #include "cros_ec_typec.h"
>  
>  #include <linux/usb/typec_dp.h>
> +#include <linux/usb/typec_tbt.h>
>  #include <linux/usb/pd_vdo.h>
>  
>  #include "cros_typec_altmode.h"
> @@ -67,6 +68,8 @@ static int cros_typec_altmode_enter(struct typec_altmode *alt, u32 *vdo)
>  
>  	if (data->sid == USB_TYPEC_DP_SID)
>  		req.mode_to_enter = CROS_EC_ALTMODE_DP;
> +	else if (data->sid == USB_TYPEC_TBT_SID)
> +		req.mode_to_enter = CROS_EC_ALTMODE_TBT;
>  	else
>  		return -EOPNOTSUPP;
>  
> @@ -196,6 +199,53 @@ static int cros_typec_displayport_vdm(struct typec_altmode *alt, u32 header,
>  	return 0;
>  }
>  
> +static int cros_typec_thunderbolt_vdm(struct typec_altmode *alt, u32 header,
> +				      const u32 *data, int count)
> +{
> +	struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
> +
> +	int cmd_type = PD_VDO_CMDT(header);
> +	int cmd = PD_VDO_CMD(header);
> +	int svdm_version;

I suppose that with the current approach this misses the ap_mode_entry
check. If it gets moved to cros_typec_altmode_vdm(), then it should be
okay.

> +
> +	svdm_version = typec_altmode_get_svdm_version(alt);
> +	if (svdm_version < 0)
> +		return svdm_version;
> +
> +	switch (cmd_type) {
> +	case CMDT_INIT:
> +		if (PD_VDO_SVDM_VER(header) < svdm_version) {
> +			typec_partner_set_svdm_version(adata->port->partner,
> +						       PD_VDO_SVDM_VER(header));
> +			svdm_version = PD_VDO_SVDM_VER(header);
> +		}
> +
> +		adata->header = VDO(adata->sid, 1, svdm_version, cmd);
> +		adata->header |= VDO_OPOS(adata->mode);
> +
> +		switch (cmd) {
> +		case CMD_ENTER_MODE:
> +			/* Don't respond to the enter mode vdm because it
> +			 * triggers mux configuration. This is handled directly
> +			 * by the cros_ec_typec driver so the Thunderbolt driver
> +			 * doesn't need to be involved.
> +			 */
> +			break;
> +		default:
> +			adata->header |= VDO_CMDT(CMDT_RSP_ACK);
> +			schedule_work(&adata->work);
> +			break;
> +		}
> +
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +
>  static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
>  				      const u32 *data, int count)
>  {
> @@ -204,6 +254,9 @@ static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
>  	if (adata->sid == USB_TYPEC_DP_SID)
>  		return cros_typec_displayport_vdm(alt, header, data, count);
>  
> +	if (adata->sid == USB_TYPEC_TBT_SID)
> +		return cros_typec_thunderbolt_vdm(alt, header, data, count);
> +
>  	return -EINVAL;
>  }
>  
> @@ -273,3 +326,35 @@ cros_typec_register_displayport(struct cros_typec_port *port,
>  	return alt;
>  }
>  #endif
> +
> +#if IS_ENABLED(CONFIG_TYPEC_TBT_ALTMODE)
> +struct typec_altmode *
> +cros_typec_register_thunderbolt(struct cros_typec_port *port,
> +				struct typec_altmode_desc *desc)
> +{
> +	struct typec_altmode *alt;
> +	struct cros_typec_altmode_data *data;
> +
> +	alt = typec_port_register_altmode(port->port, desc);
> +	if (IS_ERR(alt))
> +		return alt;
> +
> +	data = devm_kzalloc(&alt->dev, sizeof(*data), GFP_KERNEL);
> +	if (!data) {
> +		typec_unregister_altmode(alt);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	INIT_WORK(&data->work, cros_typec_altmode_work);
> +	data->alt = alt;
> +	data->port = port;
> +	data->ap_mode_entry = true;
> +	data->sid = desc->svid;
> +	data->mode = desc->mode;
> +
> +	typec_altmode_set_ops(alt, &cros_typec_altmode_ops);
> +	typec_altmode_set_drvdata(alt, data);
> +
> +	return alt;
> +}
> +#endif
> diff --git a/drivers/platform/chrome/cros_typec_altmode.h b/drivers/platform/chrome/cros_typec_altmode.h
> index c6f8fb02c99c..810b553ddcd8 100644
> --- a/drivers/platform/chrome/cros_typec_altmode.h
> +++ b/drivers/platform/chrome/cros_typec_altmode.h
> @@ -31,4 +31,18 @@ static inline int cros_typec_displayport_status_update(struct typec_altmode *alt
>  	return 0;
>  }
>  #endif
> +
> +#if IS_ENABLED(CONFIG_TYPEC_TBT_ALTMODE)
> +struct typec_altmode *
> +cros_typec_register_thunderbolt(struct cros_typec_port *port,
> +				struct typec_altmode_desc *desc);
> +#else
> +static inline struct typec_altmode *
> +cros_typec_register_thunderbolt(struct cros_typec_port *port,
> +				struct typec_altmode_desc *desc)
> +{
> +	return typec_port_register_altmode(port->port, desc);
> +}
> +#endif
> +
>  #endif /* __CROS_TYPEC_ALTMODE_H__ */
> -- 
> 2.47.0.277.g8800431eea-goog
> 

-- 
With best wishes
Dmitry

Re: [PATCH v3 6/7] platform/chrome: cros_ec_typec: Thunderbolt support

Posted by Abhishek Pandit-Subedi 1 week, 2 days ago

On Fri, Nov 8, 2024 at 10:41 PM Dmitry Baryshkov
<dmitry.baryshkov@linaro.org> wrote:
>
> On Thu, Nov 07, 2024 at 11:29:59AM -0800, Abhishek Pandit-Subedi wrote:
> > Add support for entering and exiting Thunderbolt alt-mode using AP
> > driven alt-mode.
> >
> > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > ---
> >
> > Changes in v3:
> > - Fix usage of TBT sid and mode.
> > - Removed unused vdm operations during altmode registration
> >
> > Changes in v2:
> > - Refactored thunderbolt support into cros_typec_altmode.c
> >
> >  drivers/platform/chrome/Makefile             |  3 +
> >  drivers/platform/chrome/cros_ec_typec.c      | 23 +++---
> >  drivers/platform/chrome/cros_typec_altmode.c | 85 ++++++++++++++++++++
> >  drivers/platform/chrome/cros_typec_altmode.h | 14 ++++
> >  4 files changed, 114 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
> > index 2f90d4db8099..b9b1281de063 100644
> > --- a/drivers/platform/chrome/Makefile
> > +++ b/drivers/platform/chrome/Makefile
> > @@ -21,6 +21,9 @@ cros-ec-typec-objs                  := cros_ec_typec.o cros_typec_vdm.o
> >  ifneq ($(CONFIG_TYPEC_DP_ALTMODE),)
> >       cros-ec-typec-objs              += cros_typec_altmode.o
> >  endif
> > +ifneq ($(CONFIG_TYPEC_TBT_ALTMODE),)
> > +     cros-ec-typec-objs              += cros_typec_altmode.o
> > +endif
>
> Doesn't this also result in the object file being included twice and
> thus in a duplicate symbols declaration?

I was trying to figure out how to add this file if either of those
config options existed in
https://docs.kernel.org/kbuild/makefiles.html#built-in-object-goals-obj-y
and it says, "Duplicates in the lists are allowed: the first instance
will be linked into built-in.a and succeeding instances will be
ignored."

Is there a preferred way of doing the following in the Makefile:
    if (defined(CONFIG_TYPEC_TBT_ALTMODE) ||
defined(CONFIG_TYPEC_DP_ALTMODE)) {...}

I briefly considered the following and dropped it because it is
terrible readability-wise:
  ifneq ($(CONFIG_TYPEC_TBT_ALTMODE)$(CONFIG_TYPEC_DP_ALTMODE),)

>
> >  obj-$(CONFIG_CROS_EC_TYPEC)          += cros-ec-typec.o
> >
> >  obj-$(CONFIG_CROS_EC_LPC)            += cros_ec_lpcs.o
> > diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
> > index 3a6f5f2717b9..558b618df63c 100644
> > --- a/drivers/platform/chrome/cros_ec_typec.c
> > +++ b/drivers/platform/chrome/cros_ec_typec.c
> > @@ -302,18 +302,19 @@ static int cros_typec_register_port_altmodes(struct cros_typec_data *typec,
> >
> >       /*
> >        * Register TBT compatibility alt mode. The EC will not enter the mode
> > -      * if it doesn't support it, so it's safe to register it unconditionally
> > -      * here for now.
> > +      * if it doesn't support it and it will not enter automatically by
> > +      * design so we can use the |ap_driven_altmode| feature to check if we
> > +      * should register it.
> >        */
> > -     memset(&desc, 0, sizeof(desc));
> > -     desc.svid = USB_TYPEC_TBT_SID;
> > -     desc.mode = TYPEC_ANY_MODE;
> > -     amode = typec_port_register_altmode(port->port, &desc);
> > -     if (IS_ERR(amode))
> > -             return PTR_ERR(amode);
> > -     port->port_altmode[CROS_EC_ALTMODE_TBT] = amode;
> > -     typec_altmode_set_drvdata(amode, port);
> > -     amode->ops = &port_amode_ops;
> > +     if (typec->ap_driven_altmode) {
> > +             memset(&desc, 0, sizeof(desc));
> > +             desc.svid = USB_TYPEC_TBT_SID;
> > +             desc.mode = TBT_MODE;
> > +             amode = cros_typec_register_thunderbolt(port, &desc);
> > +             if (IS_ERR(amode))
> > +                     return PTR_ERR(amode);
> > +             port->port_altmode[CROS_EC_ALTMODE_TBT] = amode;
> > +     }
> >
> >       port->state.alt = NULL;
> >       port->state.mode = TYPEC_STATE_USB;
> > diff --git a/drivers/platform/chrome/cros_typec_altmode.c b/drivers/platform/chrome/cros_typec_altmode.c
> > index 3598b8a6ceee..9cf2cef6c277 100644
> > --- a/drivers/platform/chrome/cros_typec_altmode.c
> > +++ b/drivers/platform/chrome/cros_typec_altmode.c
> > @@ -8,6 +8,7 @@
> >  #include "cros_ec_typec.h"
> >
> >  #include <linux/usb/typec_dp.h>
> > +#include <linux/usb/typec_tbt.h>
> >  #include <linux/usb/pd_vdo.h>
> >
> >  #include "cros_typec_altmode.h"
> > @@ -67,6 +68,8 @@ static int cros_typec_altmode_enter(struct typec_altmode *alt, u32 *vdo)
> >
> >       if (data->sid == USB_TYPEC_DP_SID)
> >               req.mode_to_enter = CROS_EC_ALTMODE_DP;
> > +     else if (data->sid == USB_TYPEC_TBT_SID)
> > +             req.mode_to_enter = CROS_EC_ALTMODE_TBT;
> >       else
> >               return -EOPNOTSUPP;
> >
> > @@ -196,6 +199,53 @@ static int cros_typec_displayport_vdm(struct typec_altmode *alt, u32 header,
> >       return 0;
> >  }
> >
> > +static int cros_typec_thunderbolt_vdm(struct typec_altmode *alt, u32 header,
> > +                                   const u32 *data, int count)
> > +{
> > +     struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
> > +
> > +     int cmd_type = PD_VDO_CMDT(header);
> > +     int cmd = PD_VDO_CMD(header);
> > +     int svdm_version;
>
> I suppose that with the current approach this misses the ap_mode_entry
> check. If it gets moved to cros_typec_altmode_vdm(), then it should be
> okay.

We don't register the thunderbolt port driver if ap_mode_entry is
false so it's an unnecessary check.

>
> > +
> > +     svdm_version = typec_altmode_get_svdm_version(alt);
> > +     if (svdm_version < 0)
> > +             return svdm_version;
> > +
> > +     switch (cmd_type) {
> > +     case CMDT_INIT:
> > +             if (PD_VDO_SVDM_VER(header) < svdm_version) {
> > +                     typec_partner_set_svdm_version(adata->port->partner,
> > +                                                    PD_VDO_SVDM_VER(header));
> > +                     svdm_version = PD_VDO_SVDM_VER(header);
> > +             }
> > +
> > +             adata->header = VDO(adata->sid, 1, svdm_version, cmd);
> > +             adata->header |= VDO_OPOS(adata->mode);
> > +
> > +             switch (cmd) {
> > +             case CMD_ENTER_MODE:
> > +                     /* Don't respond to the enter mode vdm because it
> > +                      * triggers mux configuration. This is handled directly
> > +                      * by the cros_ec_typec driver so the Thunderbolt driver
> > +                      * doesn't need to be involved.
> > +                      */
> > +                     break;
> > +             default:
> > +                     adata->header |= VDO_CMDT(CMDT_RSP_ACK);
> > +                     schedule_work(&adata->work);
> > +                     break;
> > +             }
> > +
> > +             break;
> > +     default:
> > +             break;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +
> >  static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
> >                                     const u32 *data, int count)
> >  {
> > @@ -204,6 +254,9 @@ static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
> >       if (adata->sid == USB_TYPEC_DP_SID)
> >               return cros_typec_displayport_vdm(alt, header, data, count);
> >
> > +     if (adata->sid == USB_TYPEC_TBT_SID)
> > +             return cros_typec_thunderbolt_vdm(alt, header, data, count);
> > +
> >       return -EINVAL;
> >  }
> >
> > @@ -273,3 +326,35 @@ cros_typec_register_displayport(struct cros_typec_port *port,
> >       return alt;
> >  }
> >  #endif
> > +
> > +#if IS_ENABLED(CONFIG_TYPEC_TBT_ALTMODE)
> > +struct typec_altmode *
> > +cros_typec_register_thunderbolt(struct cros_typec_port *port,
> > +                             struct typec_altmode_desc *desc)
> > +{
> > +     struct typec_altmode *alt;
> > +     struct cros_typec_altmode_data *data;
> > +
> > +     alt = typec_port_register_altmode(port->port, desc);
> > +     if (IS_ERR(alt))
> > +             return alt;
> > +
> > +     data = devm_kzalloc(&alt->dev, sizeof(*data), GFP_KERNEL);
> > +     if (!data) {
> > +             typec_unregister_altmode(alt);
> > +             return ERR_PTR(-ENOMEM);
> > +     }
> > +
> > +     INIT_WORK(&data->work, cros_typec_altmode_work);
> > +     data->alt = alt;
> > +     data->port = port;
> > +     data->ap_mode_entry = true;
> > +     data->sid = desc->svid;
> > +     data->mode = desc->mode;
> > +
> > +     typec_altmode_set_ops(alt, &cros_typec_altmode_ops);
> > +     typec_altmode_set_drvdata(alt, data);
> > +
> > +     return alt;
> > +}
> > +#endif
> > diff --git a/drivers/platform/chrome/cros_typec_altmode.h b/drivers/platform/chrome/cros_typec_altmode.h
> > index c6f8fb02c99c..810b553ddcd8 100644
> > --- a/drivers/platform/chrome/cros_typec_altmode.h
> > +++ b/drivers/platform/chrome/cros_typec_altmode.h
> > @@ -31,4 +31,18 @@ static inline int cros_typec_displayport_status_update(struct typec_altmode *alt
> >       return 0;
> >  }
> >  #endif
> > +
> > +#if IS_ENABLED(CONFIG_TYPEC_TBT_ALTMODE)
> > +struct typec_altmode *
> > +cros_typec_register_thunderbolt(struct cros_typec_port *port,
> > +                             struct typec_altmode_desc *desc);
> > +#else
> > +static inline struct typec_altmode *
> > +cros_typec_register_thunderbolt(struct cros_typec_port *port,
> > +                             struct typec_altmode_desc *desc)
> > +{
> > +     return typec_port_register_altmode(port->port, desc);
> > +}
> > +#endif
> > +
> >  #endif /* __CROS_TYPEC_ALTMODE_H__ */
> > --
> > 2.47.0.277.g8800431eea-goog
> >
>
> --
> With best wishes
> Dmitry

Re: [PATCH v3 6/7] platform/chrome: cros_ec_typec: Thunderbolt support

Posted by Dmitry Baryshkov 1 week, 2 days ago

On Wed, Nov 13, 2024 at 08:01:57PM -0800, Abhishek Pandit-Subedi wrote:
> On Fri, Nov 8, 2024 at 10:41 PM Dmitry Baryshkov
> <dmitry.baryshkov@linaro.org> wrote:
> >
> > On Thu, Nov 07, 2024 at 11:29:59AM -0800, Abhishek Pandit-Subedi wrote:
> > > Add support for entering and exiting Thunderbolt alt-mode using AP
> > > driven alt-mode.
> > >
> > > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > > ---
> > >
> > > Changes in v3:
> > > - Fix usage of TBT sid and mode.
> > > - Removed unused vdm operations during altmode registration
> > >
> > > Changes in v2:
> > > - Refactored thunderbolt support into cros_typec_altmode.c
> > >
> > >  drivers/platform/chrome/Makefile             |  3 +
> > >  drivers/platform/chrome/cros_ec_typec.c      | 23 +++---
> > >  drivers/platform/chrome/cros_typec_altmode.c | 85 ++++++++++++++++++++
> > >  drivers/platform/chrome/cros_typec_altmode.h | 14 ++++
> > >  4 files changed, 114 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
> > > index 2f90d4db8099..b9b1281de063 100644
> > > --- a/drivers/platform/chrome/Makefile
> > > +++ b/drivers/platform/chrome/Makefile
> > > @@ -21,6 +21,9 @@ cros-ec-typec-objs                  := cros_ec_typec.o cros_typec_vdm.o
> > >  ifneq ($(CONFIG_TYPEC_DP_ALTMODE),)
> > >       cros-ec-typec-objs              += cros_typec_altmode.o
> > >  endif
> > > +ifneq ($(CONFIG_TYPEC_TBT_ALTMODE),)
> > > +     cros-ec-typec-objs              += cros_typec_altmode.o
> > > +endif
> >
> > Doesn't this also result in the object file being included twice and
> > thus in a duplicate symbols declaration?
> 
> I was trying to figure out how to add this file if either of those
> config options existed in
> https://docs.kernel.org/kbuild/makefiles.html#built-in-object-goals-obj-y
> and it says, "Duplicates in the lists are allowed: the first instance
> will be linked into built-in.a and succeeding instances will be
> ignored."
> 
> Is there a preferred way of doing the following in the Makefile:
>     if (defined(CONFIG_TYPEC_TBT_ALTMODE) ||
> defined(CONFIG_TYPEC_DP_ALTMODE)) {...}
> 
> I briefly considered the following and dropped it because it is
> terrible readability-wise:
>   ifneq ($(CONFIG_TYPEC_TBT_ALTMODE)$(CONFIG_TYPEC_DP_ALTMODE),)

The usual way would to define new Kconfig symbol:

config CROS_EC_TYPEC_ALTMODES
	bool # Note, no description here, don't show in menuconfig
	help
	  Selectable symbol to enable altmodes

config CROS_EC_TYPEC
	...
	select CROS_EC_TYPEC_ALTMODES if CONFIG_TYPEC_DP_ALTMODE
	select CROS_EC_TYPEC_ALTMODES if CONFIG_TYPEC_TBT_ALTMODE
	...

----

cros-ec-typec-$(CONFIG_CROS_EC_TYPEC_ALTMODES) += cros_typec_altmode.o

> 
> >
> > >  obj-$(CONFIG_CROS_EC_TYPEC)          += cros-ec-typec.o
> > >
> > >  obj-$(CONFIG_CROS_EC_LPC)            += cros_ec_lpcs.o
> > > diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
> > > index 3a6f5f2717b9..558b618df63c 100644
> > > --- a/drivers/platform/chrome/cros_ec_typec.c
> > > +++ b/drivers/platform/chrome/cros_ec_typec.c
> > > @@ -302,18 +302,19 @@ static int cros_typec_register_port_altmodes(struct cros_typec_data *typec,
> > >
> > >       /*
> > >        * Register TBT compatibility alt mode. The EC will not enter the mode
> > > -      * if it doesn't support it, so it's safe to register it unconditionally
> > > -      * here for now.
> > > +      * if it doesn't support it and it will not enter automatically by
> > > +      * design so we can use the |ap_driven_altmode| feature to check if we
> > > +      * should register it.
> > >        */
> > > -     memset(&desc, 0, sizeof(desc));
> > > -     desc.svid = USB_TYPEC_TBT_SID;
> > > -     desc.mode = TYPEC_ANY_MODE;
> > > -     amode = typec_port_register_altmode(port->port, &desc);
> > > -     if (IS_ERR(amode))
> > > -             return PTR_ERR(amode);
> > > -     port->port_altmode[CROS_EC_ALTMODE_TBT] = amode;
> > > -     typec_altmode_set_drvdata(amode, port);
> > > -     amode->ops = &port_amode_ops;
> > > +     if (typec->ap_driven_altmode) {
> > > +             memset(&desc, 0, sizeof(desc));
> > > +             desc.svid = USB_TYPEC_TBT_SID;
> > > +             desc.mode = TBT_MODE;
> > > +             amode = cros_typec_register_thunderbolt(port, &desc);
> > > +             if (IS_ERR(amode))
> > > +                     return PTR_ERR(amode);
> > > +             port->port_altmode[CROS_EC_ALTMODE_TBT] = amode;
> > > +     }
> > >
> > >       port->state.alt = NULL;
> > >       port->state.mode = TYPEC_STATE_USB;
> > > diff --git a/drivers/platform/chrome/cros_typec_altmode.c b/drivers/platform/chrome/cros_typec_altmode.c
> > > index 3598b8a6ceee..9cf2cef6c277 100644
> > > --- a/drivers/platform/chrome/cros_typec_altmode.c
> > > +++ b/drivers/platform/chrome/cros_typec_altmode.c
> > > @@ -8,6 +8,7 @@
> > >  #include "cros_ec_typec.h"
> > >
> > >  #include <linux/usb/typec_dp.h>
> > > +#include <linux/usb/typec_tbt.h>
> > >  #include <linux/usb/pd_vdo.h>
> > >
> > >  #include "cros_typec_altmode.h"
> > > @@ -67,6 +68,8 @@ static int cros_typec_altmode_enter(struct typec_altmode *alt, u32 *vdo)
> > >
> > >       if (data->sid == USB_TYPEC_DP_SID)
> > >               req.mode_to_enter = CROS_EC_ALTMODE_DP;
> > > +     else if (data->sid == USB_TYPEC_TBT_SID)
> > > +             req.mode_to_enter = CROS_EC_ALTMODE_TBT;
> > >       else
> > >               return -EOPNOTSUPP;
> > >
> > > @@ -196,6 +199,53 @@ static int cros_typec_displayport_vdm(struct typec_altmode *alt, u32 header,
> > >       return 0;
> > >  }
> > >
> > > +static int cros_typec_thunderbolt_vdm(struct typec_altmode *alt, u32 header,
> > > +                                   const u32 *data, int count)
> > > +{
> > > +     struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
> > > +
> > > +     int cmd_type = PD_VDO_CMDT(header);
> > > +     int cmd = PD_VDO_CMD(header);
> > > +     int svdm_version;
> >
> > I suppose that with the current approach this misses the ap_mode_entry
> > check. If it gets moved to cros_typec_altmode_vdm(), then it should be
> > okay.
> 
> We don't register the thunderbolt port driver if ap_mode_entry is
> false so it's an unnecessary check.

Why don't you register it? It would allow userspace to understand, what
is happening, e.g. that the Type-C has switched to the TBT mode.

> 
> >
> > > +
> > > +     svdm_version = typec_altmode_get_svdm_version(alt);
> > > +     if (svdm_version < 0)
> > > +             return svdm_version;
> > > +
> > > +     switch (cmd_type) {
> > > +     case CMDT_INIT:
> > > +             if (PD_VDO_SVDM_VER(header) < svdm_version) {
> > > +                     typec_partner_set_svdm_version(adata->port->partner,
> > > +                                                    PD_VDO_SVDM_VER(header));
> > > +                     svdm_version = PD_VDO_SVDM_VER(header);
> > > +             }
> > > +
> > > +             adata->header = VDO(adata->sid, 1, svdm_version, cmd);
> > > +             adata->header |= VDO_OPOS(adata->mode);
> > > +
> > > +             switch (cmd) {
> > > +             case CMD_ENTER_MODE:
> > > +                     /* Don't respond to the enter mode vdm because it
> > > +                      * triggers mux configuration. This is handled directly
> > > +                      * by the cros_ec_typec driver so the Thunderbolt driver
> > > +                      * doesn't need to be involved.
> > > +                      */
> > > +                     break;
> > > +             default:
> > > +                     adata->header |= VDO_CMDT(CMDT_RSP_ACK);
> > > +                     schedule_work(&adata->work);
> > > +                     break;
> > > +             }
> > > +
> > > +             break;
> > > +     default:
> > > +             break;
> > > +     }
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +
> > >  static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
> > >                                     const u32 *data, int count)
> > >  {
> > > @@ -204,6 +254,9 @@ static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
> > >       if (adata->sid == USB_TYPEC_DP_SID)
> > >               return cros_typec_displayport_vdm(alt, header, data, count);
> > >
> > > +     if (adata->sid == USB_TYPEC_TBT_SID)
> > > +             return cros_typec_thunderbolt_vdm(alt, header, data, count);
> > > +
> > >       return -EINVAL;
> > >  }
> > >
> > > @@ -273,3 +326,35 @@ cros_typec_register_displayport(struct cros_typec_port *port,
> > >       return alt;
> > >  }
> > >  #endif
> > > +
> > > +#if IS_ENABLED(CONFIG_TYPEC_TBT_ALTMODE)
> > > +struct typec_altmode *
> > > +cros_typec_register_thunderbolt(struct cros_typec_port *port,
> > > +                             struct typec_altmode_desc *desc)
> > > +{
> > > +     struct typec_altmode *alt;
> > > +     struct cros_typec_altmode_data *data;
> > > +
> > > +     alt = typec_port_register_altmode(port->port, desc);
> > > +     if (IS_ERR(alt))
> > > +             return alt;
> > > +
> > > +     data = devm_kzalloc(&alt->dev, sizeof(*data), GFP_KERNEL);
> > > +     if (!data) {
> > > +             typec_unregister_altmode(alt);
> > > +             return ERR_PTR(-ENOMEM);
> > > +     }
> > > +
> > > +     INIT_WORK(&data->work, cros_typec_altmode_work);
> > > +     data->alt = alt;
> > > +     data->port = port;
> > > +     data->ap_mode_entry = true;
> > > +     data->sid = desc->svid;
> > > +     data->mode = desc->mode;
> > > +
> > > +     typec_altmode_set_ops(alt, &cros_typec_altmode_ops);
> > > +     typec_altmode_set_drvdata(alt, data);
> > > +
> > > +     return alt;
> > > +}
> > > +#endif
> > > diff --git a/drivers/platform/chrome/cros_typec_altmode.h b/drivers/platform/chrome/cros_typec_altmode.h
> > > index c6f8fb02c99c..810b553ddcd8 100644
> > > --- a/drivers/platform/chrome/cros_typec_altmode.h
> > > +++ b/drivers/platform/chrome/cros_typec_altmode.h
> > > @@ -31,4 +31,18 @@ static inline int cros_typec_displayport_status_update(struct typec_altmode *alt
> > >       return 0;
> > >  }
> > >  #endif
> > > +
> > > +#if IS_ENABLED(CONFIG_TYPEC_TBT_ALTMODE)
> > > +struct typec_altmode *
> > > +cros_typec_register_thunderbolt(struct cros_typec_port *port,
> > > +                             struct typec_altmode_desc *desc);
> > > +#else
> > > +static inline struct typec_altmode *
> > > +cros_typec_register_thunderbolt(struct cros_typec_port *port,
> > > +                             struct typec_altmode_desc *desc)
> > > +{
> > > +     return typec_port_register_altmode(port->port, desc);
> > > +}
> > > +#endif
> > > +
> > >  #endif /* __CROS_TYPEC_ALTMODE_H__ */
> > > --
> > > 2.47.0.277.g8800431eea-goog
> > >
> >
> > --
> > With best wishes
> > Dmitry

-- 
With best wishes
Dmitry

[PATCH v3 1/7] usb: typec: Only use SVID for matching altmodes
[PATCH v3 2/7] usb: typec: Add driver for Thunderbolt 3 Alternate Mode
[PATCH v3 3/7] usb: typec: Check port is active before enter mode on probe
[PATCH v3 4/7] platform/chrome: cros_ec_typec: Update partner altmode active
[PATCH v3 5/7] platform/chrome: cros_ec_typec: Displayport support
[PATCH v3 6/7] platform/chrome: cros_ec_typec: Thunderbolt support
[PATCH v3 7/7] platform/chrome: cros_ec_typec: Disable tbt on port