diff mbox series

[v3,2/7] usb: typec: Add driver for Thunderbolt 3 Alternate Mode

Message ID 20241107112955.v3.2.I3080b036e8de0b9957c57c1c3059db7149c5e549@changeid (mailing list archive)
State Superseded
Headers show
Series Thunderbolt and DP altmode support for cros-ec-typec | expand

Commit Message

Abhishek Pandit-Subedi Nov. 7, 2024, 7:29 p.m. UTC
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>

Thunderbolt 3 Alternate Mode entry flow is described in
USB Type-C Specification Release 2.0.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes:
* Delay cable + plug checks so that the module doesn't fail to probe
  if cable + plug information isn't available by the time the partner
  altmode is registered.
* Remove unncessary brace after if (IS_ERR(plug))

The rest of this patch should be the same as Heikki's original RFC.


Changes in v3:
- Revert rename of TYPEC_TBT_MODE
- Remove mode from typec_device_id

Changes in v2:
- Use <linux/usb/typec_tbt.h> and add missing TBT_CABLE_ROUNDED
- Pass struct typec_thunderbolt_data to typec_altmode_notify
- Rename TYPEC_TBT_MODE to USB_TYPEC_TBT_MODE
- Use USB_TYPEC_TBT_SID and USB_TYPEC_TBT_MODE for device id
- Change module license to GPL due to checkpatch warning

 drivers/usb/typec/altmodes/Kconfig       |   9 +
 drivers/usb/typec/altmodes/Makefile      |   2 +
 drivers/usb/typec/altmodes/thunderbolt.c | 308 +++++++++++++++++++++++
 include/linux/usb/typec_tbt.h            |   1 +
 4 files changed, 320 insertions(+)
 create mode 100644 drivers/usb/typec/altmodes/thunderbolt.c

Comments

Dmitry Baryshkov Nov. 9, 2024, 6:21 a.m. UTC | #1
On Thu, Nov 07, 2024 at 11:29:55AM -0800, Abhishek Pandit-Subedi wrote:
> From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> 
> Thunderbolt 3 Alternate Mode entry flow is described in
> USB Type-C Specification Release 2.0.
> 
> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> ---
> 
> Changes:
> * Delay cable + plug checks so that the module doesn't fail to probe
>   if cable + plug information isn't available by the time the partner
>   altmode is registered.
> * Remove unncessary brace after if (IS_ERR(plug))
> 
> The rest of this patch should be the same as Heikki's original RFC.
> 
> 
> Changes in v3:
> - Revert rename of TYPEC_TBT_MODE
> - Remove mode from typec_device_id
> 
> Changes in v2:
> - Use <linux/usb/typec_tbt.h> and add missing TBT_CABLE_ROUNDED
> - Pass struct typec_thunderbolt_data to typec_altmode_notify
> - Rename TYPEC_TBT_MODE to USB_TYPEC_TBT_MODE
> - Use USB_TYPEC_TBT_SID and USB_TYPEC_TBT_MODE for device id
> - Change module license to GPL due to checkpatch warning
> 
>  drivers/usb/typec/altmodes/Kconfig       |   9 +
>  drivers/usb/typec/altmodes/Makefile      |   2 +
>  drivers/usb/typec/altmodes/thunderbolt.c | 308 +++++++++++++++++++++++
>  include/linux/usb/typec_tbt.h            |   1 +
>  4 files changed, 320 insertions(+)
>  create mode 100644 drivers/usb/typec/altmodes/thunderbolt.c
> 
> diff --git a/drivers/usb/typec/altmodes/Kconfig b/drivers/usb/typec/altmodes/Kconfig
> index 1a6b5e872b0d..7867fa7c405d 100644
> --- a/drivers/usb/typec/altmodes/Kconfig
> +++ b/drivers/usb/typec/altmodes/Kconfig
> @@ -23,4 +23,13 @@ config TYPEC_NVIDIA_ALTMODE
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called typec_nvidia.
>  
> +config TYPEC_TBT_ALTMODE
> +	tristate "Thunderbolt3 Alternate Mode driver"
> +	help
> +	  Select this option if you have Thunderbolt3 hardware on your
> +	  system.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called typec_thunderbolt.
> +
>  endmenu
> diff --git a/drivers/usb/typec/altmodes/Makefile b/drivers/usb/typec/altmodes/Makefile
> index 45717548b396..508a68351bd2 100644
> --- a/drivers/usb/typec/altmodes/Makefile
> +++ b/drivers/usb/typec/altmodes/Makefile
> @@ -4,3 +4,5 @@ obj-$(CONFIG_TYPEC_DP_ALTMODE)		+= typec_displayport.o
>  typec_displayport-y			:= displayport.o
>  obj-$(CONFIG_TYPEC_NVIDIA_ALTMODE)	+= typec_nvidia.o
>  typec_nvidia-y				:= nvidia.o
> +obj-$(CONFIG_TYPEC_TBT_ALTMODE)		+= typec_thunderbolt.o
> +typec_thunderbolt-y			:= thunderbolt.o
> diff --git a/drivers/usb/typec/altmodes/thunderbolt.c b/drivers/usb/typec/altmodes/thunderbolt.c
> new file mode 100644
> index 000000000000..a945b9d35a1d
> --- /dev/null
> +++ b/drivers/usb/typec/altmodes/thunderbolt.c
> @@ -0,0 +1,308 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/**
> + * USB Typec-C Thuderbolt3 Alternate Mode driver
> + *
> + * Copyright (C) 2019 Intel Corporation
> + * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/mutex.h>
> +#include <linux/module.h>
> +#include <linux/usb/pd_vdo.h>
> +#include <linux/usb/typec_altmode.h>
> +#include <linux/usb/typec_tbt.h>
> +
> +enum tbt_state {
> +	TBT_STATE_IDLE,
> +	TBT_STATE_SOP_P_ENTER,
> +	TBT_STATE_SOP_PP_ENTER,
> +	TBT_STATE_ENTER,
> +	TBT_STATE_EXIT,
> +	TBT_STATE_SOP_PP_EXIT,
> +	TBT_STATE_SOP_P_EXIT
> +};
> +
> +struct tbt_altmode {
> +	enum tbt_state state;
> +	struct typec_cable *cable;
> +	struct typec_altmode *alt;
> +	struct typec_altmode *plug[2];
> +	u32 enter_vdo;
> +
> +	struct work_struct work;
> +	struct mutex lock; /* device lock */
> +};
> +
> +static bool tbt_ready(struct typec_altmode *alt);
> +
> +static int tbt_enter_mode(struct tbt_altmode *tbt)
> +{
> +	struct typec_altmode *plug = tbt->plug[TYPEC_PLUG_SOP_P];
> +	u32 vdo;
> +
> +	vdo = tbt->alt->vdo & (TBT_VENDOR_SPECIFIC_B0 | TBT_VENDOR_SPECIFIC_B1);
> +	vdo |= tbt->alt->vdo & TBT_INTEL_SPECIFIC_B0;
> +	vdo |= TBT_MODE;
> +
> +	if (plug) {
> +		if (typec_cable_is_active(tbt->cable))
> +			vdo |= TBT_ENTER_MODE_ACTIVE_CABLE;
> +
> +		vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_SPEED(plug->vdo));
> +		vdo |= plug->vdo & TBT_CABLE_ROUNDED;
> +		vdo |= plug->vdo & TBT_CABLE_OPTICAL;
> +		vdo |= plug->vdo & TBT_CABLE_RETIMER;
> +		vdo |= plug->vdo & TBT_CABLE_LINK_TRAINING;
> +	} else {
> +		vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_USB3_PASSIVE);
> +	}
> +
> +	tbt->enter_vdo = vdo;
> +	return typec_altmode_enter(tbt->alt, &vdo);
> +}
> +
> +static void tbt_altmode_work(struct work_struct *work)
> +{
> +	struct tbt_altmode *tbt = container_of(work, struct tbt_altmode, work);
> +	int ret;
> +
> +	mutex_lock(&tbt->lock);
> +
> +	switch (tbt->state) {
> +	case TBT_STATE_SOP_P_ENTER:
> +		ret = typec_altmode_enter(tbt->plug[TYPEC_PLUG_SOP_P], NULL);

typec_cable_altmode_enter() ?

> +		if (ret)
> +			dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_P]->dev,
> +				"failed to enter mode (%d)\n", ret);
> +		break;
> +	case TBT_STATE_SOP_PP_ENTER:
> +		ret = typec_altmode_enter(tbt->plug[TYPEC_PLUG_SOP_PP], NULL);

typec_cable_altmode_enter() ?

> +		if (ret)
> +			dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_PP]->dev,
> +				"failed to enter mode (%d)\n", ret);
> +		break;
> +	case TBT_STATE_ENTER:
> +		ret = tbt_enter_mode(tbt);
> +		if (ret)
> +			dev_dbg(&tbt->alt->dev, "failed to enter mode (%d)\n",
> +				ret);
> +		break;
> +	case TBT_STATE_EXIT:
> +		typec_altmode_exit(tbt->alt);
> +		break;
> +	case TBT_STATE_SOP_PP_EXIT:
> +		typec_altmode_exit(tbt->plug[TYPEC_PLUG_SOP_PP]);
> +		break;
> +	case TBT_STATE_SOP_P_EXIT:
> +		typec_altmode_exit(tbt->plug[TYPEC_PLUG_SOP_P]);
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	tbt->state = TBT_STATE_IDLE;
> +
> +	mutex_unlock(&tbt->lock);
> +}
> +
> +static int tbt_altmode_vdm(struct typec_altmode *alt,
> +			   const u32 hdr, const u32 *vdo, int count)
> +{
> +	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> +	int cmd_type = PD_VDO_CMDT(hdr);
> +	int cmd = PD_VDO_CMD(hdr);
> +
> +	mutex_lock(&tbt->lock);
> +
> +	if (tbt->state != TBT_STATE_IDLE) {
> +		mutex_unlock(&tbt->lock);
> +		return -EBUSY;
> +	}
> +
> +	switch (cmd_type) {
> +	case CMDT_RSP_ACK:
> +		switch (cmd) {
> +		case CMD_ENTER_MODE:
> +			/*
> +			 * Following the order describeded in USB Type-C Spec
> +			 * R2.0 Section 6.7.3.
> +			 */
> +			if (alt == tbt->plug[TYPEC_PLUG_SOP_P]) {
> +				if (tbt->plug[TYPEC_PLUG_SOP_PP])
> +					tbt->state = TBT_STATE_SOP_PP_ENTER;
> +				else
> +					tbt->state = TBT_STATE_ENTER;
> +			} else if (alt == tbt->plug[TYPEC_PLUG_SOP_PP]) {
> +				tbt->state = TBT_STATE_ENTER;
> +			} else {
> +				struct typec_thunderbolt_data data;
> +
> +				data.device_mode = tbt->alt->vdo;
> +				data.cable_mode =
> +					tbt->plug[TYPEC_PLUG_SOP_P] ?
> +						tbt->plug[TYPEC_PLUG_SOP_P]
> +							->vdo :

I'd say, please move the -> vdo to the previous line, otherwise it's a
bit unreadable.

> +						0;
> +				data.enter_vdo = tbt->enter_vdo;
> +
> +				typec_altmode_notify(alt, TYPEC_STATE_MODAL, &data);
> +			}
> +			break;
> +		case CMD_EXIT_MODE:
> +			if (alt == tbt->alt) {
> +				if (tbt->plug[TYPEC_PLUG_SOP_PP])
> +					tbt->state = TBT_STATE_SOP_PP_EXIT;
> +				else if (tbt->plug[TYPEC_PLUG_SOP_P])
> +					tbt->state = TBT_STATE_SOP_P_EXIT;
> +			} else if (alt == tbt->plug[TYPEC_PLUG_SOP_PP]) {
> +				tbt->state = TBT_STATE_SOP_P_EXIT;
> +			}
> +			break;
> +		}
> +		break;
> +	case CMDT_RSP_NAK:
> +		switch (cmd) {
> +		case CMD_ENTER_MODE:
> +			dev_warn(&alt->dev, "Enter Mode refused\n");
> +			break;
> +		default:
> +			break;
> +		}
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	if (tbt->state != TBT_STATE_IDLE)
> +		schedule_work(&tbt->work);
> +
> +	mutex_unlock(&tbt->lock);
> +
> +	return 0;
> +}
> +
> +static int tbt_altmode_activate(struct typec_altmode *alt, int activate)
> +{
> +	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> +	int ret;
> +
> +	mutex_lock(&tbt->lock);
> +
> +	if (!tbt_ready(alt))
> +		return -ENODEV;
> +
> +	/* Preventing the user space from entering/exiting the cable alt mode */
> +	if (alt != tbt->alt)
> +		ret = -EPERM;
> +	else if (activate)
> +		ret = tbt_enter_mode(tbt);
> +	else
> +		ret = typec_altmode_exit(alt);
> +
> +	mutex_unlock(&tbt->lock);
> +
> +	return ret;
> +}
> +
> +static const struct typec_altmode_ops tbt_altmode_ops = {
> +	.vdm		= tbt_altmode_vdm,
> +	.activate	= tbt_altmode_activate
> +};
> +
> +static int tbt_altmode_probe(struct typec_altmode *alt)
> +{
> +	struct tbt_altmode *tbt;
> +
> +	tbt = devm_kzalloc(&alt->dev, sizeof(*tbt), GFP_KERNEL);
> +	if (!tbt)
> +		return -ENOMEM;
> +
> +	INIT_WORK(&tbt->work, tbt_altmode_work);
> +	mutex_init(&tbt->lock);
> +	tbt->alt = alt;
> +
> +	alt->desc = "Thunderbolt3";
> +	typec_altmode_set_drvdata(alt, tbt);
> +	typec_altmode_set_ops(alt, &tbt_altmode_ops);
> +
> +	if (tbt_ready(alt)) {
> +		if (tbt->plug[TYPEC_PLUG_SOP_PP])
> +			tbt->state = TBT_STATE_SOP_PP_ENTER;
> +		else if (tbt->plug[TYPEC_PLUG_SOP_P])
> +			tbt->state = TBT_STATE_SOP_P_ENTER;
> +		else
> +			tbt->state = TBT_STATE_ENTER;
> +		schedule_work(&tbt->work);
> +	}
> +
> +	return 0;
> +}
> +
> +static void tbt_altmode_remove(struct typec_altmode *alt)
> +{
> +	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> +
> +	for (int i = TYPEC_PLUG_SOP_PP; i > 0; --i) {
> +		if (tbt->plug[i])
> +			typec_altmode_put_plug(tbt->plug[i]);
> +	}
> +
> +	if (tbt->cable)
> +		typec_cable_put(tbt->cable);
> +}
> +
> +static bool tbt_ready(struct typec_altmode *alt)
> +{
> +	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> +	struct typec_altmode *plug;
> +
> +	if (tbt->cable)
> +		return true;
> +
> +	/* Thundebolt 3 requires a cable with eMarker */
> +	tbt->cable = typec_cable_get(typec_altmode2port(tbt->alt));
> +	if (!tbt->cable)
> +		return false;
> +
> +	/* We accept systems without SOP' or SOP''. This means the port altmode
> +	 * driver will be responsible for properly ordering entry/exit.
> +	 */
> +	for (int i = 0; i < TYPEC_PLUG_SOP_PP + 1; i++) {
> +		plug = typec_altmode_get_plug(tbt->alt, i);
> +		if (IS_ERR(plug))
> +			continue;
> +
> +		if (!plug || plug->svid != USB_TYPEC_VENDOR_INTEL)

!= USB_TYPEC_TBT_SID

> +			break;
> +
> +		plug->desc = "Thunderbolt3";
> +		plug->ops = &tbt_altmode_ops;

Should this be plug->cable_ops ?

> +		typec_altmode_set_drvdata(plug, tbt);
> +
> +		tbt->plug[i] = plug;
> +	}
> +
> +	return true;
> +}
> +
> +static const struct typec_device_id tbt_typec_id[] = {
> +	{ USB_TYPEC_TBT_SID },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(typec, tbt_typec_id);
> +
> +static struct typec_altmode_driver tbt_altmode_driver = {
> +	.id_table = tbt_typec_id,
> +	.probe = tbt_altmode_probe,
> +	.remove = tbt_altmode_remove,
> +	.driver = {
> +		.name = "typec-thunderbolt",
> +		.owner = THIS_MODULE,

Should not be necessary, it is set by __typec_altmode_register_driver()

> +	}
> +};
> +module_typec_altmode_driver(tbt_altmode_driver);
> +
> +MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Thunderbolt3 USB Type-C Alternate Mode");
> diff --git a/include/linux/usb/typec_tbt.h b/include/linux/usb/typec_tbt.h
> index fa97d7e00f5c..55dcea12082c 100644
> --- a/include/linux/usb/typec_tbt.h
> +++ b/include/linux/usb/typec_tbt.h
> @@ -44,6 +44,7 @@ struct typec_thunderbolt_data {
>  
>  #define   TBT_GEN3_NON_ROUNDED                 0
>  #define   TBT_GEN3_GEN4_ROUNDED_NON_ROUNDED    1
> +#define TBT_CABLE_ROUNDED		BIT(19)
>  #define TBT_CABLE_OPTICAL		BIT(21)
>  #define TBT_CABLE_RETIMER		BIT(22)
>  #define TBT_CABLE_LINK_TRAINING		BIT(23)
> -- 
> 2.47.0.277.g8800431eea-goog
>
Abhishek Pandit-Subedi Nov. 14, 2024, 3:51 a.m. UTC | #2
On Fri, Nov 8, 2024 at 10:21 PM Dmitry Baryshkov
<dmitry.baryshkov@linaro.org> wrote:
>
> On Thu, Nov 07, 2024 at 11:29:55AM -0800, Abhishek Pandit-Subedi wrote:
> > From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> >
> > Thunderbolt 3 Alternate Mode entry flow is described in
> > USB Type-C Specification Release 2.0.
> >
> > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > ---
> >
> > Changes:
> > * Delay cable + plug checks so that the module doesn't fail to probe
> >   if cable + plug information isn't available by the time the partner
> >   altmode is registered.
> > * Remove unncessary brace after if (IS_ERR(plug))
> >
> > The rest of this patch should be the same as Heikki's original RFC.
> >
> >
> > Changes in v3:
> > - Revert rename of TYPEC_TBT_MODE
> > - Remove mode from typec_device_id
> >
> > Changes in v2:
> > - Use <linux/usb/typec_tbt.h> and add missing TBT_CABLE_ROUNDED
> > - Pass struct typec_thunderbolt_data to typec_altmode_notify
> > - Rename TYPEC_TBT_MODE to USB_TYPEC_TBT_MODE
> > - Use USB_TYPEC_TBT_SID and USB_TYPEC_TBT_MODE for device id
> > - Change module license to GPL due to checkpatch warning
> >
> >  drivers/usb/typec/altmodes/Kconfig       |   9 +
> >  drivers/usb/typec/altmodes/Makefile      |   2 +
> >  drivers/usb/typec/altmodes/thunderbolt.c | 308 +++++++++++++++++++++++
> >  include/linux/usb/typec_tbt.h            |   1 +
> >  4 files changed, 320 insertions(+)
> >  create mode 100644 drivers/usb/typec/altmodes/thunderbolt.c
> >
> > diff --git a/drivers/usb/typec/altmodes/Kconfig b/drivers/usb/typec/altmodes/Kconfig
> > index 1a6b5e872b0d..7867fa7c405d 100644
> > --- a/drivers/usb/typec/altmodes/Kconfig
> > +++ b/drivers/usb/typec/altmodes/Kconfig
> > @@ -23,4 +23,13 @@ config TYPEC_NVIDIA_ALTMODE
> >         To compile this driver as a module, choose M here: the
> >         module will be called typec_nvidia.
> >
> > +config TYPEC_TBT_ALTMODE
> > +     tristate "Thunderbolt3 Alternate Mode driver"
> > +     help
> > +       Select this option if you have Thunderbolt3 hardware on your
> > +       system.
> > +
> > +       To compile this driver as a module, choose M here: the
> > +       module will be called typec_thunderbolt.
> > +
> >  endmenu
> > diff --git a/drivers/usb/typec/altmodes/Makefile b/drivers/usb/typec/altmodes/Makefile
> > index 45717548b396..508a68351bd2 100644
> > --- a/drivers/usb/typec/altmodes/Makefile
> > +++ b/drivers/usb/typec/altmodes/Makefile
> > @@ -4,3 +4,5 @@ obj-$(CONFIG_TYPEC_DP_ALTMODE)                += typec_displayport.o
> >  typec_displayport-y                  := displayport.o
> >  obj-$(CONFIG_TYPEC_NVIDIA_ALTMODE)   += typec_nvidia.o
> >  typec_nvidia-y                               := nvidia.o
> > +obj-$(CONFIG_TYPEC_TBT_ALTMODE)              += typec_thunderbolt.o
> > +typec_thunderbolt-y                  := thunderbolt.o
> > diff --git a/drivers/usb/typec/altmodes/thunderbolt.c b/drivers/usb/typec/altmodes/thunderbolt.c
> > new file mode 100644
> > index 000000000000..a945b9d35a1d
> > --- /dev/null
> > +++ b/drivers/usb/typec/altmodes/thunderbolt.c
> > @@ -0,0 +1,308 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/**
> > + * USB Typec-C Thuderbolt3 Alternate Mode driver
> > + *
> > + * Copyright (C) 2019 Intel Corporation
> > + * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/mutex.h>
> > +#include <linux/module.h>
> > +#include <linux/usb/pd_vdo.h>
> > +#include <linux/usb/typec_altmode.h>
> > +#include <linux/usb/typec_tbt.h>
> > +
> > +enum tbt_state {
> > +     TBT_STATE_IDLE,
> > +     TBT_STATE_SOP_P_ENTER,
> > +     TBT_STATE_SOP_PP_ENTER,
> > +     TBT_STATE_ENTER,
> > +     TBT_STATE_EXIT,
> > +     TBT_STATE_SOP_PP_EXIT,
> > +     TBT_STATE_SOP_P_EXIT
> > +};
> > +
> > +struct tbt_altmode {
> > +     enum tbt_state state;
> > +     struct typec_cable *cable;
> > +     struct typec_altmode *alt;
> > +     struct typec_altmode *plug[2];
> > +     u32 enter_vdo;
> > +
> > +     struct work_struct work;
> > +     struct mutex lock; /* device lock */
> > +};
> > +
> > +static bool tbt_ready(struct typec_altmode *alt);
> > +
> > +static int tbt_enter_mode(struct tbt_altmode *tbt)
> > +{
> > +     struct typec_altmode *plug = tbt->plug[TYPEC_PLUG_SOP_P];
> > +     u32 vdo;
> > +
> > +     vdo = tbt->alt->vdo & (TBT_VENDOR_SPECIFIC_B0 | TBT_VENDOR_SPECIFIC_B1);
> > +     vdo |= tbt->alt->vdo & TBT_INTEL_SPECIFIC_B0;
> > +     vdo |= TBT_MODE;
> > +
> > +     if (plug) {
> > +             if (typec_cable_is_active(tbt->cable))
> > +                     vdo |= TBT_ENTER_MODE_ACTIVE_CABLE;
> > +
> > +             vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_SPEED(plug->vdo));
> > +             vdo |= plug->vdo & TBT_CABLE_ROUNDED;
> > +             vdo |= plug->vdo & TBT_CABLE_OPTICAL;
> > +             vdo |= plug->vdo & TBT_CABLE_RETIMER;
> > +             vdo |= plug->vdo & TBT_CABLE_LINK_TRAINING;
> > +     } else {
> > +             vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_USB3_PASSIVE);
> > +     }
> > +
> > +     tbt->enter_vdo = vdo;
> > +     return typec_altmode_enter(tbt->alt, &vdo);
> > +}
> > +
> > +static void tbt_altmode_work(struct work_struct *work)
> > +{
> > +     struct tbt_altmode *tbt = container_of(work, struct tbt_altmode, work);
> > +     int ret;
> > +
> > +     mutex_lock(&tbt->lock);
> > +
> > +     switch (tbt->state) {
> > +     case TBT_STATE_SOP_P_ENTER:
> > +             ret = typec_altmode_enter(tbt->plug[TYPEC_PLUG_SOP_P], NULL);
>
> typec_cable_altmode_enter() ?
>
> > +             if (ret)
> > +                     dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_P]->dev,
> > +                             "failed to enter mode (%d)\n", ret);
> > +             break;
> > +     case TBT_STATE_SOP_PP_ENTER:
> > +             ret = typec_altmode_enter(tbt->plug[TYPEC_PLUG_SOP_PP], NULL);
>
> typec_cable_altmode_enter() ?
>
> > +             if (ret)
> > +                     dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_PP]->dev,
> > +                             "failed to enter mode (%d)\n", ret);
> > +             break;
> > +     case TBT_STATE_ENTER:
> > +             ret = tbt_enter_mode(tbt);
> > +             if (ret)
> > +                     dev_dbg(&tbt->alt->dev, "failed to enter mode (%d)\n",
> > +                             ret);
> > +             break;
> > +     case TBT_STATE_EXIT:
> > +             typec_altmode_exit(tbt->alt);
> > +             break;
> > +     case TBT_STATE_SOP_PP_EXIT:
> > +             typec_altmode_exit(tbt->plug[TYPEC_PLUG_SOP_PP]);
> > +             break;
> > +     case TBT_STATE_SOP_P_EXIT:
> > +             typec_altmode_exit(tbt->plug[TYPEC_PLUG_SOP_P]);
> > +             break;
> > +     default:
> > +             break;
> > +     }
> > +
> > +     tbt->state = TBT_STATE_IDLE;
> > +
> > +     mutex_unlock(&tbt->lock);
> > +}
> > +
> > +static int tbt_altmode_vdm(struct typec_altmode *alt,
> > +                        const u32 hdr, const u32 *vdo, int count)
> > +{
> > +     struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> > +     int cmd_type = PD_VDO_CMDT(hdr);
> > +     int cmd = PD_VDO_CMD(hdr);
> > +
> > +     mutex_lock(&tbt->lock);
> > +
> > +     if (tbt->state != TBT_STATE_IDLE) {
> > +             mutex_unlock(&tbt->lock);
> > +             return -EBUSY;
> > +     }
> > +
> > +     switch (cmd_type) {
> > +     case CMDT_RSP_ACK:
> > +             switch (cmd) {
> > +             case CMD_ENTER_MODE:
> > +                     /*
> > +                      * Following the order describeded in USB Type-C Spec
> > +                      * R2.0 Section 6.7.3.
> > +                      */
> > +                     if (alt == tbt->plug[TYPEC_PLUG_SOP_P]) {
> > +                             if (tbt->plug[TYPEC_PLUG_SOP_PP])
> > +                                     tbt->state = TBT_STATE_SOP_PP_ENTER;
> > +                             else
> > +                                     tbt->state = TBT_STATE_ENTER;
> > +                     } else if (alt == tbt->plug[TYPEC_PLUG_SOP_PP]) {
> > +                             tbt->state = TBT_STATE_ENTER;
> > +                     } else {
> > +                             struct typec_thunderbolt_data data;
> > +
> > +                             data.device_mode = tbt->alt->vdo;
> > +                             data.cable_mode =
> > +                                     tbt->plug[TYPEC_PLUG_SOP_P] ?
> > +                                             tbt->plug[TYPEC_PLUG_SOP_P]
> > +                                                     ->vdo :
>
> I'd say, please move the -> vdo to the previous line, otherwise it's a
> bit unreadable.
>
> > +                                             0;
> > +                             data.enter_vdo = tbt->enter_vdo;
> > +
> > +                             typec_altmode_notify(alt, TYPEC_STATE_MODAL, &data);
> > +                     }
> > +                     break;
> > +             case CMD_EXIT_MODE:
> > +                     if (alt == tbt->alt) {
> > +                             if (tbt->plug[TYPEC_PLUG_SOP_PP])
> > +                                     tbt->state = TBT_STATE_SOP_PP_EXIT;
> > +                             else if (tbt->plug[TYPEC_PLUG_SOP_P])
> > +                                     tbt->state = TBT_STATE_SOP_P_EXIT;
> > +                     } else if (alt == tbt->plug[TYPEC_PLUG_SOP_PP]) {
> > +                             tbt->state = TBT_STATE_SOP_P_EXIT;
> > +                     }
> > +                     break;
> > +             }
> > +             break;
> > +     case CMDT_RSP_NAK:
> > +             switch (cmd) {
> > +             case CMD_ENTER_MODE:
> > +                     dev_warn(&alt->dev, "Enter Mode refused\n");
> > +                     break;
> > +             default:
> > +                     break;
> > +             }
> > +             break;
> > +     default:
> > +             break;
> > +     }
> > +
> > +     if (tbt->state != TBT_STATE_IDLE)
> > +             schedule_work(&tbt->work);
> > +
> > +     mutex_unlock(&tbt->lock);
> > +
> > +     return 0;
> > +}
> > +
> > +static int tbt_altmode_activate(struct typec_altmode *alt, int activate)
> > +{
> > +     struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> > +     int ret;
> > +
> > +     mutex_lock(&tbt->lock);
> > +
> > +     if (!tbt_ready(alt))
> > +             return -ENODEV;
> > +
> > +     /* Preventing the user space from entering/exiting the cable alt mode */
> > +     if (alt != tbt->alt)
> > +             ret = -EPERM;
> > +     else if (activate)
> > +             ret = tbt_enter_mode(tbt);
> > +     else
> > +             ret = typec_altmode_exit(alt);
> > +
> > +     mutex_unlock(&tbt->lock);
> > +
> > +     return ret;
> > +}
> > +
> > +static const struct typec_altmode_ops tbt_altmode_ops = {
> > +     .vdm            = tbt_altmode_vdm,
> > +     .activate       = tbt_altmode_activate
> > +};
> > +
> > +static int tbt_altmode_probe(struct typec_altmode *alt)
> > +{
> > +     struct tbt_altmode *tbt;
> > +
> > +     tbt = devm_kzalloc(&alt->dev, sizeof(*tbt), GFP_KERNEL);
> > +     if (!tbt)
> > +             return -ENOMEM;
> > +
> > +     INIT_WORK(&tbt->work, tbt_altmode_work);
> > +     mutex_init(&tbt->lock);
> > +     tbt->alt = alt;
> > +
> > +     alt->desc = "Thunderbolt3";
> > +     typec_altmode_set_drvdata(alt, tbt);
> > +     typec_altmode_set_ops(alt, &tbt_altmode_ops);
> > +
> > +     if (tbt_ready(alt)) {
> > +             if (tbt->plug[TYPEC_PLUG_SOP_PP])
> > +                     tbt->state = TBT_STATE_SOP_PP_ENTER;
> > +             else if (tbt->plug[TYPEC_PLUG_SOP_P])
> > +                     tbt->state = TBT_STATE_SOP_P_ENTER;
> > +             else
> > +                     tbt->state = TBT_STATE_ENTER;
> > +             schedule_work(&tbt->work);
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static void tbt_altmode_remove(struct typec_altmode *alt)
> > +{
> > +     struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> > +
> > +     for (int i = TYPEC_PLUG_SOP_PP; i > 0; --i) {
> > +             if (tbt->plug[i])
> > +                     typec_altmode_put_plug(tbt->plug[i]);
> > +     }
> > +
> > +     if (tbt->cable)
> > +             typec_cable_put(tbt->cable);
> > +}
> > +
> > +static bool tbt_ready(struct typec_altmode *alt)
> > +{
> > +     struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> > +     struct typec_altmode *plug;
> > +
> > +     if (tbt->cable)
> > +             return true;
> > +
> > +     /* Thundebolt 3 requires a cable with eMarker */
> > +     tbt->cable = typec_cable_get(typec_altmode2port(tbt->alt));
> > +     if (!tbt->cable)
> > +             return false;
> > +
> > +     /* We accept systems without SOP' or SOP''. This means the port altmode
> > +      * driver will be responsible for properly ordering entry/exit.
> > +      */
> > +     for (int i = 0; i < TYPEC_PLUG_SOP_PP + 1; i++) {
> > +             plug = typec_altmode_get_plug(tbt->alt, i);
> > +             if (IS_ERR(plug))
> > +                     continue;
> > +
> > +             if (!plug || plug->svid != USB_TYPEC_VENDOR_INTEL)
>
> != USB_TYPEC_TBT_SID
>
> > +                     break;
> > +
> > +             plug->desc = "Thunderbolt3";
> > +             plug->ops = &tbt_altmode_ops;
>
> Should this be plug->cable_ops ?
>
> > +             typec_altmode_set_drvdata(plug, tbt);
> > +
> > +             tbt->plug[i] = plug;
> > +     }
> > +
> > +     return true;
> > +}
> > +
> > +static const struct typec_device_id tbt_typec_id[] = {
> > +     { USB_TYPEC_TBT_SID },
> > +     { }
> > +};
> > +MODULE_DEVICE_TABLE(typec, tbt_typec_id);
> > +
> > +static struct typec_altmode_driver tbt_altmode_driver = {
> > +     .id_table = tbt_typec_id,
> > +     .probe = tbt_altmode_probe,
> > +     .remove = tbt_altmode_remove,
> > +     .driver = {
> > +             .name = "typec-thunderbolt",
> > +             .owner = THIS_MODULE,
>
> Should not be necessary, it is set by __typec_altmode_register_driver()
>
> > +     }
> > +};
> > +module_typec_altmode_driver(tbt_altmode_driver);
> > +
> > +MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
> > +MODULE_LICENSE("GPL");
> > +MODULE_DESCRIPTION("Thunderbolt3 USB Type-C Alternate Mode");
> > diff --git a/include/linux/usb/typec_tbt.h b/include/linux/usb/typec_tbt.h
> > index fa97d7e00f5c..55dcea12082c 100644
> > --- a/include/linux/usb/typec_tbt.h
> > +++ b/include/linux/usb/typec_tbt.h
> > @@ -44,6 +44,7 @@ struct typec_thunderbolt_data {
> >
> >  #define   TBT_GEN3_NON_ROUNDED                 0
> >  #define   TBT_GEN3_GEN4_ROUNDED_NON_ROUNDED    1
> > +#define TBT_CABLE_ROUNDED            BIT(19)
> >  #define TBT_CABLE_OPTICAL            BIT(21)
> >  #define TBT_CABLE_RETIMER            BIT(22)
> >  #define TBT_CABLE_LINK_TRAINING              BIT(23)
> > --
> > 2.47.0.277.g8800431eea-goog
> >
>
> --
> With best wishes
> Dmitry

Will address all comments in the next series.

The cable alt-modes are new to me. Looking at the implementation, one
part confuses me -- it looks like cable alt-modes expect the partner
to already be active when entering
(https://github.com/torvalds/linux/blob/master/drivers/usb/typec/bus.c#L272).
I'll reach out to the author of cable altmodes to see how to integrate
this correctly with the current series.
Benson Leung Nov. 22, 2024, 6:50 p.m. UTC | #3
Hi Abhishek,


On Thu, Nov 07, 2024 at 11:29:55AM -0800, Abhishek Pandit-Subedi wrote:
> From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> 
> Thunderbolt 3 Alternate Mode entry flow is described in
> USB Type-C Specification Release 2.0.
> 
> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> ---
> 
> Changes:
> * Delay cable + plug checks so that the module doesn't fail to probe
>   if cable + plug information isn't available by the time the partner
>   altmode is registered.
> * Remove unncessary brace after if (IS_ERR(plug))
> 
> The rest of this patch should be the same as Heikki's original RFC.
> 
> 
> Changes in v3:
> - Revert rename of TYPEC_TBT_MODE
> - Remove mode from typec_device_id
> 
> Changes in v2:
> - Use <linux/usb/typec_tbt.h> and add missing TBT_CABLE_ROUNDED
> - Pass struct typec_thunderbolt_data to typec_altmode_notify
> - Rename TYPEC_TBT_MODE to USB_TYPEC_TBT_MODE
> - Use USB_TYPEC_TBT_SID and USB_TYPEC_TBT_MODE for device id
> - Change module license to GPL due to checkpatch warning
> 
>  drivers/usb/typec/altmodes/Kconfig       |   9 +
>  drivers/usb/typec/altmodes/Makefile      |   2 +
>  drivers/usb/typec/altmodes/thunderbolt.c | 308 +++++++++++++++++++++++
>  include/linux/usb/typec_tbt.h            |   1 +
>  4 files changed, 320 insertions(+)
>  create mode 100644 drivers/usb/typec/altmodes/thunderbolt.c
> 
> diff --git a/drivers/usb/typec/altmodes/Kconfig b/drivers/usb/typec/altmodes/Kconfig
> index 1a6b5e872b0d..7867fa7c405d 100644
> --- a/drivers/usb/typec/altmodes/Kconfig
> +++ b/drivers/usb/typec/altmodes/Kconfig
> @@ -23,4 +23,13 @@ config TYPEC_NVIDIA_ALTMODE
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called typec_nvidia.
>  
> +config TYPEC_TBT_ALTMODE
> +	tristate "Thunderbolt3 Alternate Mode driver"
> +	help
> +	  Select this option if you have Thunderbolt3 hardware on your
> +	  system.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called typec_thunderbolt.
> +
>  endmenu
> diff --git a/drivers/usb/typec/altmodes/Makefile b/drivers/usb/typec/altmodes/Makefile
> index 45717548b396..508a68351bd2 100644
> --- a/drivers/usb/typec/altmodes/Makefile
> +++ b/drivers/usb/typec/altmodes/Makefile
> @@ -4,3 +4,5 @@ obj-$(CONFIG_TYPEC_DP_ALTMODE)		+= typec_displayport.o
>  typec_displayport-y			:= displayport.o
>  obj-$(CONFIG_TYPEC_NVIDIA_ALTMODE)	+= typec_nvidia.o
>  typec_nvidia-y				:= nvidia.o
> +obj-$(CONFIG_TYPEC_TBT_ALTMODE)		+= typec_thunderbolt.o
> +typec_thunderbolt-y			:= thunderbolt.o
> diff --git a/drivers/usb/typec/altmodes/thunderbolt.c b/drivers/usb/typec/altmodes/thunderbolt.c
> new file mode 100644
> index 000000000000..a945b9d35a1d
> --- /dev/null
> +++ b/drivers/usb/typec/altmodes/thunderbolt.c
> @@ -0,0 +1,308 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/**
> + * USB Typec-C Thuderbolt3 Alternate Mode driver
> + *
> + * Copyright (C) 2019 Intel Corporation
> + * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/mutex.h>
> +#include <linux/module.h>
> +#include <linux/usb/pd_vdo.h>
> +#include <linux/usb/typec_altmode.h>
> +#include <linux/usb/typec_tbt.h>
> +
> +enum tbt_state {
> +	TBT_STATE_IDLE,
> +	TBT_STATE_SOP_P_ENTER,
> +	TBT_STATE_SOP_PP_ENTER,
> +	TBT_STATE_ENTER,
> +	TBT_STATE_EXIT,
> +	TBT_STATE_SOP_PP_EXIT,
> +	TBT_STATE_SOP_P_EXIT
> +};
> +
> +struct tbt_altmode {
> +	enum tbt_state state;
> +	struct typec_cable *cable;
> +	struct typec_altmode *alt;
> +	struct typec_altmode *plug[2];
> +	u32 enter_vdo;
> +
> +	struct work_struct work;
> +	struct mutex lock; /* device lock */
> +};
> +
> +static bool tbt_ready(struct typec_altmode *alt);
> +
> +static int tbt_enter_mode(struct tbt_altmode *tbt)
> +{
> +	struct typec_altmode *plug = tbt->plug[TYPEC_PLUG_SOP_P];
> +	u32 vdo;
> +
> +	vdo = tbt->alt->vdo & (TBT_VENDOR_SPECIFIC_B0 | TBT_VENDOR_SPECIFIC_B1);
> +	vdo |= tbt->alt->vdo & TBT_INTEL_SPECIFIC_B0;
> +	vdo |= TBT_MODE;
> +
> +	if (plug) {
> +		if (typec_cable_is_active(tbt->cable))
> +			vdo |= TBT_ENTER_MODE_ACTIVE_CABLE;
> +
> +		vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_SPEED(plug->vdo));
> +		vdo |= plug->vdo & TBT_CABLE_ROUNDED;
> +		vdo |= plug->vdo & TBT_CABLE_OPTICAL;
> +		vdo |= plug->vdo & TBT_CABLE_RETIMER;
> +		vdo |= plug->vdo & TBT_CABLE_LINK_TRAINING;
> +	} else {
> +		vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_USB3_PASSIVE);
> +	}
> +
> +	tbt->enter_vdo = vdo;
> +	return typec_altmode_enter(tbt->alt, &vdo);
> +}
> +
> +static void tbt_altmode_work(struct work_struct *work)
> +{
> +	struct tbt_altmode *tbt = container_of(work, struct tbt_altmode, work);
> +	int ret;
> +
> +	mutex_lock(&tbt->lock);
> +
> +	switch (tbt->state) {
> +	case TBT_STATE_SOP_P_ENTER:
> +		ret = typec_altmode_enter(tbt->plug[TYPEC_PLUG_SOP_P], NULL);
> +		if (ret)
> +			dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_P]->dev,
> +				"failed to enter mode (%d)\n", ret);
> +		break;
> +	case TBT_STATE_SOP_PP_ENTER:
> +		ret = typec_altmode_enter(tbt->plug[TYPEC_PLUG_SOP_PP], NULL);
> +		if (ret)
> +			dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_PP]->dev,
> +				"failed to enter mode (%d)\n", ret);
> +		break;
> +	case TBT_STATE_ENTER:
> +		ret = tbt_enter_mode(tbt);
> +		if (ret)
> +			dev_dbg(&tbt->alt->dev, "failed to enter mode (%d)\n",
> +				ret);
> +		break;
> +	case TBT_STATE_EXIT:
> +		typec_altmode_exit(tbt->alt);
> +		break;
> +	case TBT_STATE_SOP_PP_EXIT:
> +		typec_altmode_exit(tbt->plug[TYPEC_PLUG_SOP_PP]);
> +		break;
> +	case TBT_STATE_SOP_P_EXIT:
> +		typec_altmode_exit(tbt->plug[TYPEC_PLUG_SOP_P]);
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	tbt->state = TBT_STATE_IDLE;
> +
> +	mutex_unlock(&tbt->lock);
> +}
> +
> +static int tbt_altmode_vdm(struct typec_altmode *alt,
> +			   const u32 hdr, const u32 *vdo, int count)
> +{
> +	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> +	int cmd_type = PD_VDO_CMDT(hdr);
> +	int cmd = PD_VDO_CMD(hdr);
> +
> +	mutex_lock(&tbt->lock);
> +
> +	if (tbt->state != TBT_STATE_IDLE) {
> +		mutex_unlock(&tbt->lock);
> +		return -EBUSY;
> +	}
> +
> +	switch (cmd_type) {
> +	case CMDT_RSP_ACK:
> +		switch (cmd) {
> +		case CMD_ENTER_MODE:
> +			/*
> +			 * Following the order describeded in USB Type-C Spec
> +			 * R2.0 Section 6.7.3.
> +			 */
> +			if (alt == tbt->plug[TYPEC_PLUG_SOP_P]) {
> +				if (tbt->plug[TYPEC_PLUG_SOP_PP])
> +					tbt->state = TBT_STATE_SOP_PP_ENTER;
> +				else
> +					tbt->state = TBT_STATE_ENTER;
> +			} else if (alt == tbt->plug[TYPEC_PLUG_SOP_PP]) {
> +				tbt->state = TBT_STATE_ENTER;
> +			} else {
> +				struct typec_thunderbolt_data data;
> +
> +				data.device_mode = tbt->alt->vdo;
> +				data.cable_mode =
> +					tbt->plug[TYPEC_PLUG_SOP_P] ?
> +						tbt->plug[TYPEC_PLUG_SOP_P]
> +							->vdo :
> +						0;
> +				data.enter_vdo = tbt->enter_vdo;
> +
> +				typec_altmode_notify(alt, TYPEC_STATE_MODAL, &data);
> +			}
> +			break;
> +		case CMD_EXIT_MODE:
> +			if (alt == tbt->alt) {
> +				if (tbt->plug[TYPEC_PLUG_SOP_PP])
> +					tbt->state = TBT_STATE_SOP_PP_EXIT;
> +				else if (tbt->plug[TYPEC_PLUG_SOP_P])
> +					tbt->state = TBT_STATE_SOP_P_EXIT;
> +			} else if (alt == tbt->plug[TYPEC_PLUG_SOP_PP]) {
> +				tbt->state = TBT_STATE_SOP_P_EXIT;
> +			}
> +			break;
> +		}
> +		break;
> +	case CMDT_RSP_NAK:
> +		switch (cmd) {
> +		case CMD_ENTER_MODE:
> +			dev_warn(&alt->dev, "Enter Mode refused\n");
> +			break;
> +		default:
> +			break;
> +		}
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	if (tbt->state != TBT_STATE_IDLE)
> +		schedule_work(&tbt->work);
> +
> +	mutex_unlock(&tbt->lock);
> +
> +	return 0;
> +}
> +
> +static int tbt_altmode_activate(struct typec_altmode *alt, int activate)
> +{
> +	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> +	int ret;
> +
> +	mutex_lock(&tbt->lock);
> +
> +	if (!tbt_ready(alt))
> +		return -ENODEV;


You need to mutex_unlock(&tbt->lock);  before the return.

Credit to danielgeorgem@google.com for his catching this in his code review.

> +
> +	/* Preventing the user space from entering/exiting the cable alt mode */
> +	if (alt != tbt->alt)
> +		ret = -EPERM;
> +	else if (activate)
> +		ret = tbt_enter_mode(tbt);
> +	else
> +		ret = typec_altmode_exit(alt);
> +
> +	mutex_unlock(&tbt->lock);
> +
> +	return ret;
> +}
> +
> +static const struct typec_altmode_ops tbt_altmode_ops = {
> +	.vdm		= tbt_altmode_vdm,
> +	.activate	= tbt_altmode_activate
> +};
> +
> +static int tbt_altmode_probe(struct typec_altmode *alt)
> +{
> +	struct tbt_altmode *tbt;
> +
> +	tbt = devm_kzalloc(&alt->dev, sizeof(*tbt), GFP_KERNEL);
> +	if (!tbt)
> +		return -ENOMEM;
> +
> +	INIT_WORK(&tbt->work, tbt_altmode_work);
> +	mutex_init(&tbt->lock);
> +	tbt->alt = alt;
> +
> +	alt->desc = "Thunderbolt3";
> +	typec_altmode_set_drvdata(alt, tbt);
> +	typec_altmode_set_ops(alt, &tbt_altmode_ops);
> +
> +	if (tbt_ready(alt)) {
> +		if (tbt->plug[TYPEC_PLUG_SOP_PP])
> +			tbt->state = TBT_STATE_SOP_PP_ENTER;
> +		else if (tbt->plug[TYPEC_PLUG_SOP_P])
> +			tbt->state = TBT_STATE_SOP_P_ENTER;
> +		else
> +			tbt->state = TBT_STATE_ENTER;
> +		schedule_work(&tbt->work);
> +	}
> +
> +	return 0;
> +}
> +
> +static void tbt_altmode_remove(struct typec_altmode *alt)
> +{
> +	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> +
> +	for (int i = TYPEC_PLUG_SOP_PP; i > 0; --i) {
> +		if (tbt->plug[i])
> +			typec_altmode_put_plug(tbt->plug[i]);
> +	}
> +
> +	if (tbt->cable)
> +		typec_cable_put(tbt->cable);
> +}
> +
> +static bool tbt_ready(struct typec_altmode *alt)
> +{
> +	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> +	struct typec_altmode *plug;
> +
> +	if (tbt->cable)
> +		return true;
> +
> +	/* Thundebolt 3 requires a cable with eMarker */
> +	tbt->cable = typec_cable_get(typec_altmode2port(tbt->alt));
> +	if (!tbt->cable)
> +		return false;
> +
> +	/* We accept systems without SOP' or SOP''. This means the port altmode
> +	 * driver will be responsible for properly ordering entry/exit.
> +	 */
> +	for (int i = 0; i < TYPEC_PLUG_SOP_PP + 1; i++) {
> +		plug = typec_altmode_get_plug(tbt->alt, i);
> +		if (IS_ERR(plug))
> +			continue;
> +
> +		if (!plug || plug->svid != USB_TYPEC_VENDOR_INTEL)
> +			break;
> +
> +		plug->desc = "Thunderbolt3";
> +		plug->ops = &tbt_altmode_ops;
> +		typec_altmode_set_drvdata(plug, tbt);
> +
> +		tbt->plug[i] = plug;
> +	}
> +
> +	return true;
> +}
> +
> +static const struct typec_device_id tbt_typec_id[] = {
> +	{ USB_TYPEC_TBT_SID },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(typec, tbt_typec_id);
> +
> +static struct typec_altmode_driver tbt_altmode_driver = {
> +	.id_table = tbt_typec_id,
> +	.probe = tbt_altmode_probe,
> +	.remove = tbt_altmode_remove,
> +	.driver = {
> +		.name = "typec-thunderbolt",
> +		.owner = THIS_MODULE,
> +	}
> +};
> +module_typec_altmode_driver(tbt_altmode_driver);
> +
> +MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Thunderbolt3 USB Type-C Alternate Mode");
> diff --git a/include/linux/usb/typec_tbt.h b/include/linux/usb/typec_tbt.h
> index fa97d7e00f5c..55dcea12082c 100644
> --- a/include/linux/usb/typec_tbt.h
> +++ b/include/linux/usb/typec_tbt.h
> @@ -44,6 +44,7 @@ struct typec_thunderbolt_data {
>  
>  #define   TBT_GEN3_NON_ROUNDED                 0
>  #define   TBT_GEN3_GEN4_ROUNDED_NON_ROUNDED    1
> +#define TBT_CABLE_ROUNDED		BIT(19)
>  #define TBT_CABLE_OPTICAL		BIT(21)
>  #define TBT_CABLE_RETIMER		BIT(22)
>  #define TBT_CABLE_LINK_TRAINING		BIT(23)
> -- 
> 2.47.0.277.g8800431eea-goog
> 
>
Abhishek Pandit-Subedi Dec. 6, 2024, 10:27 p.m. UTC | #4
On Fri, Nov 22, 2024 at 10:51 AM Benson Leung <bleung@google.com> wrote:
>
> Hi Abhishek,
>
>
> On Thu, Nov 07, 2024 at 11:29:55AM -0800, Abhishek Pandit-Subedi wrote:
> > From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> >
> > Thunderbolt 3 Alternate Mode entry flow is described in
> > USB Type-C Specification Release 2.0.
> >
> > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > ---
> >
> > Changes:
> > * Delay cable + plug checks so that the module doesn't fail to probe
> >   if cable + plug information isn't available by the time the partner
> >   altmode is registered.
> > * Remove unncessary brace after if (IS_ERR(plug))
> >
> > The rest of this patch should be the same as Heikki's original RFC.
> >
> >
> > Changes in v3:
> > - Revert rename of TYPEC_TBT_MODE
> > - Remove mode from typec_device_id
> >
> > Changes in v2:
> > - Use <linux/usb/typec_tbt.h> and add missing TBT_CABLE_ROUNDED
> > - Pass struct typec_thunderbolt_data to typec_altmode_notify
> > - Rename TYPEC_TBT_MODE to USB_TYPEC_TBT_MODE
> > - Use USB_TYPEC_TBT_SID and USB_TYPEC_TBT_MODE for device id
> > - Change module license to GPL due to checkpatch warning
> >
> >  drivers/usb/typec/altmodes/Kconfig       |   9 +
> >  drivers/usb/typec/altmodes/Makefile      |   2 +
> >  drivers/usb/typec/altmodes/thunderbolt.c | 308 +++++++++++++++++++++++
> >  include/linux/usb/typec_tbt.h            |   1 +
> >  4 files changed, 320 insertions(+)
> >  create mode 100644 drivers/usb/typec/altmodes/thunderbolt.c
> >
> > diff --git a/drivers/usb/typec/altmodes/Kconfig b/drivers/usb/typec/altmodes/Kconfig
> > index 1a6b5e872b0d..7867fa7c405d 100644
> > --- a/drivers/usb/typec/altmodes/Kconfig
> > +++ b/drivers/usb/typec/altmodes/Kconfig
> > @@ -23,4 +23,13 @@ config TYPEC_NVIDIA_ALTMODE
> >         To compile this driver as a module, choose M here: the
> >         module will be called typec_nvidia.
> >
> > +config TYPEC_TBT_ALTMODE
> > +     tristate "Thunderbolt3 Alternate Mode driver"
> > +     help
> > +       Select this option if you have Thunderbolt3 hardware on your
> > +       system.
> > +
> > +       To compile this driver as a module, choose M here: the
> > +       module will be called typec_thunderbolt.
> > +
> >  endmenu
> > diff --git a/drivers/usb/typec/altmodes/Makefile b/drivers/usb/typec/altmodes/Makefile
> > index 45717548b396..508a68351bd2 100644
> > --- a/drivers/usb/typec/altmodes/Makefile
> > +++ b/drivers/usb/typec/altmodes/Makefile
> > @@ -4,3 +4,5 @@ obj-$(CONFIG_TYPEC_DP_ALTMODE)                += typec_displayport.o
> >  typec_displayport-y                  := displayport.o
> >  obj-$(CONFIG_TYPEC_NVIDIA_ALTMODE)   += typec_nvidia.o
> >  typec_nvidia-y                               := nvidia.o
> > +obj-$(CONFIG_TYPEC_TBT_ALTMODE)              += typec_thunderbolt.o
> > +typec_thunderbolt-y                  := thunderbolt.o
> > diff --git a/drivers/usb/typec/altmodes/thunderbolt.c b/drivers/usb/typec/altmodes/thunderbolt.c
> > new file mode 100644
> > index 000000000000..a945b9d35a1d
> > --- /dev/null
> > +++ b/drivers/usb/typec/altmodes/thunderbolt.c
> > @@ -0,0 +1,308 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/**
> > + * USB Typec-C Thuderbolt3 Alternate Mode driver
> > + *
> > + * Copyright (C) 2019 Intel Corporation
> > + * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/mutex.h>
> > +#include <linux/module.h>
> > +#include <linux/usb/pd_vdo.h>
> > +#include <linux/usb/typec_altmode.h>
> > +#include <linux/usb/typec_tbt.h>
> > +
> > +enum tbt_state {
> > +     TBT_STATE_IDLE,
> > +     TBT_STATE_SOP_P_ENTER,
> > +     TBT_STATE_SOP_PP_ENTER,
> > +     TBT_STATE_ENTER,
> > +     TBT_STATE_EXIT,
> > +     TBT_STATE_SOP_PP_EXIT,
> > +     TBT_STATE_SOP_P_EXIT
> > +};
> > +
> > +struct tbt_altmode {
> > +     enum tbt_state state;
> > +     struct typec_cable *cable;
> > +     struct typec_altmode *alt;
> > +     struct typec_altmode *plug[2];
> > +     u32 enter_vdo;
> > +
> > +     struct work_struct work;
> > +     struct mutex lock; /* device lock */
> > +};
> > +
> > +static bool tbt_ready(struct typec_altmode *alt);
> > +
> > +static int tbt_enter_mode(struct tbt_altmode *tbt)
> > +{
> > +     struct typec_altmode *plug = tbt->plug[TYPEC_PLUG_SOP_P];
> > +     u32 vdo;
> > +
> > +     vdo = tbt->alt->vdo & (TBT_VENDOR_SPECIFIC_B0 | TBT_VENDOR_SPECIFIC_B1);
> > +     vdo |= tbt->alt->vdo & TBT_INTEL_SPECIFIC_B0;
> > +     vdo |= TBT_MODE;
> > +
> > +     if (plug) {
> > +             if (typec_cable_is_active(tbt->cable))
> > +                     vdo |= TBT_ENTER_MODE_ACTIVE_CABLE;
> > +
> > +             vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_SPEED(plug->vdo));
> > +             vdo |= plug->vdo & TBT_CABLE_ROUNDED;
> > +             vdo |= plug->vdo & TBT_CABLE_OPTICAL;
> > +             vdo |= plug->vdo & TBT_CABLE_RETIMER;
> > +             vdo |= plug->vdo & TBT_CABLE_LINK_TRAINING;
> > +     } else {
> > +             vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_USB3_PASSIVE);
> > +     }
> > +
> > +     tbt->enter_vdo = vdo;
> > +     return typec_altmode_enter(tbt->alt, &vdo);
> > +}
> > +
> > +static void tbt_altmode_work(struct work_struct *work)
> > +{
> > +     struct tbt_altmode *tbt = container_of(work, struct tbt_altmode, work);
> > +     int ret;
> > +
> > +     mutex_lock(&tbt->lock);
> > +
> > +     switch (tbt->state) {
> > +     case TBT_STATE_SOP_P_ENTER:
> > +             ret = typec_altmode_enter(tbt->plug[TYPEC_PLUG_SOP_P], NULL);
> > +             if (ret)
> > +                     dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_P]->dev,
> > +                             "failed to enter mode (%d)\n", ret);
> > +             break;
> > +     case TBT_STATE_SOP_PP_ENTER:
> > +             ret = typec_altmode_enter(tbt->plug[TYPEC_PLUG_SOP_PP], NULL);
> > +             if (ret)
> > +                     dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_PP]->dev,
> > +                             "failed to enter mode (%d)\n", ret);
> > +             break;
> > +     case TBT_STATE_ENTER:
> > +             ret = tbt_enter_mode(tbt);
> > +             if (ret)
> > +                     dev_dbg(&tbt->alt->dev, "failed to enter mode (%d)\n",
> > +                             ret);
> > +             break;
> > +     case TBT_STATE_EXIT:
> > +             typec_altmode_exit(tbt->alt);
> > +             break;
> > +     case TBT_STATE_SOP_PP_EXIT:
> > +             typec_altmode_exit(tbt->plug[TYPEC_PLUG_SOP_PP]);
> > +             break;
> > +     case TBT_STATE_SOP_P_EXIT:
> > +             typec_altmode_exit(tbt->plug[TYPEC_PLUG_SOP_P]);
> > +             break;
> > +     default:
> > +             break;
> > +     }
> > +
> > +     tbt->state = TBT_STATE_IDLE;
> > +
> > +     mutex_unlock(&tbt->lock);
> > +}
> > +
> > +static int tbt_altmode_vdm(struct typec_altmode *alt,
> > +                        const u32 hdr, const u32 *vdo, int count)
> > +{
> > +     struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> > +     int cmd_type = PD_VDO_CMDT(hdr);
> > +     int cmd = PD_VDO_CMD(hdr);
> > +
> > +     mutex_lock(&tbt->lock);
> > +
> > +     if (tbt->state != TBT_STATE_IDLE) {
> > +             mutex_unlock(&tbt->lock);
> > +             return -EBUSY;
> > +     }
> > +
> > +     switch (cmd_type) {
> > +     case CMDT_RSP_ACK:
> > +             switch (cmd) {
> > +             case CMD_ENTER_MODE:
> > +                     /*
> > +                      * Following the order describeded in USB Type-C Spec
> > +                      * R2.0 Section 6.7.3.
> > +                      */
> > +                     if (alt == tbt->plug[TYPEC_PLUG_SOP_P]) {
> > +                             if (tbt->plug[TYPEC_PLUG_SOP_PP])
> > +                                     tbt->state = TBT_STATE_SOP_PP_ENTER;
> > +                             else
> > +                                     tbt->state = TBT_STATE_ENTER;
> > +                     } else if (alt == tbt->plug[TYPEC_PLUG_SOP_PP]) {
> > +                             tbt->state = TBT_STATE_ENTER;
> > +                     } else {
> > +                             struct typec_thunderbolt_data data;
> > +
> > +                             data.device_mode = tbt->alt->vdo;
> > +                             data.cable_mode =
> > +                                     tbt->plug[TYPEC_PLUG_SOP_P] ?
> > +                                             tbt->plug[TYPEC_PLUG_SOP_P]
> > +                                                     ->vdo :
> > +                                             0;
> > +                             data.enter_vdo = tbt->enter_vdo;
> > +
> > +                             typec_altmode_notify(alt, TYPEC_STATE_MODAL, &data);
> > +                     }
> > +                     break;
> > +             case CMD_EXIT_MODE:
> > +                     if (alt == tbt->alt) {
> > +                             if (tbt->plug[TYPEC_PLUG_SOP_PP])
> > +                                     tbt->state = TBT_STATE_SOP_PP_EXIT;
> > +                             else if (tbt->plug[TYPEC_PLUG_SOP_P])
> > +                                     tbt->state = TBT_STATE_SOP_P_EXIT;
> > +                     } else if (alt == tbt->plug[TYPEC_PLUG_SOP_PP]) {
> > +                             tbt->state = TBT_STATE_SOP_P_EXIT;
> > +                     }
> > +                     break;
> > +             }
> > +             break;
> > +     case CMDT_RSP_NAK:
> > +             switch (cmd) {
> > +             case CMD_ENTER_MODE:
> > +                     dev_warn(&alt->dev, "Enter Mode refused\n");
> > +                     break;
> > +             default:
> > +                     break;
> > +             }
> > +             break;
> > +     default:
> > +             break;
> > +     }
> > +
> > +     if (tbt->state != TBT_STATE_IDLE)
> > +             schedule_work(&tbt->work);
> > +
> > +     mutex_unlock(&tbt->lock);
> > +
> > +     return 0;
> > +}
> > +
> > +static int tbt_altmode_activate(struct typec_altmode *alt, int activate)
> > +{
> > +     struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> > +     int ret;
> > +
> > +     mutex_lock(&tbt->lock);
> > +
> > +     if (!tbt_ready(alt))
> > +             return -ENODEV;
>
>
> You need to mutex_unlock(&tbt->lock);  before the return.
>
> Credit to danielgeorgem@google.com for his catching this in his code review.

Good catch! Next update will have this.

Sorry for late replies -- it took me a while to get back to this +
refactor to use the new cable ops apis. In the process, I also
discovered some mistakes in how we were entering TBT from .activate so
I opted to follow a similar pattern to what RD has done for DP with
cables.

v4 will come soon.

>
> > +
> > +     /* Preventing the user space from entering/exiting the cable alt mode */
> > +     if (alt != tbt->alt)
> > +             ret = -EPERM;
> > +     else if (activate)
> > +             ret = tbt_enter_mode(tbt);
> > +     else
> > +             ret = typec_altmode_exit(alt);
> > +
> > +     mutex_unlock(&tbt->lock);
> > +
> > +     return ret;
> > +}
> > +
> > +static const struct typec_altmode_ops tbt_altmode_ops = {
> > +     .vdm            = tbt_altmode_vdm,
> > +     .activate       = tbt_altmode_activate
> > +};
> > +
> > +static int tbt_altmode_probe(struct typec_altmode *alt)
> > +{
> > +     struct tbt_altmode *tbt;
> > +
> > +     tbt = devm_kzalloc(&alt->dev, sizeof(*tbt), GFP_KERNEL);
> > +     if (!tbt)
> > +             return -ENOMEM;
> > +
> > +     INIT_WORK(&tbt->work, tbt_altmode_work);
> > +     mutex_init(&tbt->lock);
> > +     tbt->alt = alt;
> > +
> > +     alt->desc = "Thunderbolt3";
> > +     typec_altmode_set_drvdata(alt, tbt);
> > +     typec_altmode_set_ops(alt, &tbt_altmode_ops);
> > +
> > +     if (tbt_ready(alt)) {
> > +             if (tbt->plug[TYPEC_PLUG_SOP_PP])
> > +                     tbt->state = TBT_STATE_SOP_PP_ENTER;
> > +             else if (tbt->plug[TYPEC_PLUG_SOP_P])
> > +                     tbt->state = TBT_STATE_SOP_P_ENTER;
> > +             else
> > +                     tbt->state = TBT_STATE_ENTER;
> > +             schedule_work(&tbt->work);
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static void tbt_altmode_remove(struct typec_altmode *alt)
> > +{
> > +     struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> > +
> > +     for (int i = TYPEC_PLUG_SOP_PP; i > 0; --i) {
> > +             if (tbt->plug[i])
> > +                     typec_altmode_put_plug(tbt->plug[i]);
> > +     }
> > +
> > +     if (tbt->cable)
> > +             typec_cable_put(tbt->cable);
> > +}
> > +
> > +static bool tbt_ready(struct typec_altmode *alt)
> > +{
> > +     struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
> > +     struct typec_altmode *plug;
> > +
> > +     if (tbt->cable)
> > +             return true;
> > +
> > +     /* Thundebolt 3 requires a cable with eMarker */
> > +     tbt->cable = typec_cable_get(typec_altmode2port(tbt->alt));
> > +     if (!tbt->cable)
> > +             return false;
> > +
> > +     /* We accept systems without SOP' or SOP''. This means the port altmode
> > +      * driver will be responsible for properly ordering entry/exit.
> > +      */
> > +     for (int i = 0; i < TYPEC_PLUG_SOP_PP + 1; i++) {
> > +             plug = typec_altmode_get_plug(tbt->alt, i);
> > +             if (IS_ERR(plug))
> > +                     continue;
> > +
> > +             if (!plug || plug->svid != USB_TYPEC_VENDOR_INTEL)
> > +                     break;
> > +
> > +             plug->desc = "Thunderbolt3";
> > +             plug->ops = &tbt_altmode_ops;
> > +             typec_altmode_set_drvdata(plug, tbt);
> > +
> > +             tbt->plug[i] = plug;
> > +     }
> > +
> > +     return true;
> > +}
> > +
> > +static const struct typec_device_id tbt_typec_id[] = {
> > +     { USB_TYPEC_TBT_SID },
> > +     { }
> > +};
> > +MODULE_DEVICE_TABLE(typec, tbt_typec_id);
> > +
> > +static struct typec_altmode_driver tbt_altmode_driver = {
> > +     .id_table = tbt_typec_id,
> > +     .probe = tbt_altmode_probe,
> > +     .remove = tbt_altmode_remove,
> > +     .driver = {
> > +             .name = "typec-thunderbolt",
> > +             .owner = THIS_MODULE,
> > +     }
> > +};
> > +module_typec_altmode_driver(tbt_altmode_driver);
> > +
> > +MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
> > +MODULE_LICENSE("GPL");
> > +MODULE_DESCRIPTION("Thunderbolt3 USB Type-C Alternate Mode");
> > diff --git a/include/linux/usb/typec_tbt.h b/include/linux/usb/typec_tbt.h
> > index fa97d7e00f5c..55dcea12082c 100644
> > --- a/include/linux/usb/typec_tbt.h
> > +++ b/include/linux/usb/typec_tbt.h
> > @@ -44,6 +44,7 @@ struct typec_thunderbolt_data {
> >
> >  #define   TBT_GEN3_NON_ROUNDED                 0
> >  #define   TBT_GEN3_GEN4_ROUNDED_NON_ROUNDED    1
> > +#define TBT_CABLE_ROUNDED            BIT(19)
> >  #define TBT_CABLE_OPTICAL            BIT(21)
> >  #define TBT_CABLE_RETIMER            BIT(22)
> >  #define TBT_CABLE_LINK_TRAINING              BIT(23)
> > --
> > 2.47.0.277.g8800431eea-goog
> >
> >
diff mbox series

Patch

diff --git a/drivers/usb/typec/altmodes/Kconfig b/drivers/usb/typec/altmodes/Kconfig
index 1a6b5e872b0d..7867fa7c405d 100644
--- a/drivers/usb/typec/altmodes/Kconfig
+++ b/drivers/usb/typec/altmodes/Kconfig
@@ -23,4 +23,13 @@  config TYPEC_NVIDIA_ALTMODE
 	  To compile this driver as a module, choose M here: the
 	  module will be called typec_nvidia.
 
+config TYPEC_TBT_ALTMODE
+	tristate "Thunderbolt3 Alternate Mode driver"
+	help
+	  Select this option if you have Thunderbolt3 hardware on your
+	  system.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called typec_thunderbolt.
+
 endmenu
diff --git a/drivers/usb/typec/altmodes/Makefile b/drivers/usb/typec/altmodes/Makefile
index 45717548b396..508a68351bd2 100644
--- a/drivers/usb/typec/altmodes/Makefile
+++ b/drivers/usb/typec/altmodes/Makefile
@@ -4,3 +4,5 @@  obj-$(CONFIG_TYPEC_DP_ALTMODE)		+= typec_displayport.o
 typec_displayport-y			:= displayport.o
 obj-$(CONFIG_TYPEC_NVIDIA_ALTMODE)	+= typec_nvidia.o
 typec_nvidia-y				:= nvidia.o
+obj-$(CONFIG_TYPEC_TBT_ALTMODE)		+= typec_thunderbolt.o
+typec_thunderbolt-y			:= thunderbolt.o
diff --git a/drivers/usb/typec/altmodes/thunderbolt.c b/drivers/usb/typec/altmodes/thunderbolt.c
new file mode 100644
index 000000000000..a945b9d35a1d
--- /dev/null
+++ b/drivers/usb/typec/altmodes/thunderbolt.c
@@ -0,0 +1,308 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * USB Typec-C Thuderbolt3 Alternate Mode driver
+ *
+ * Copyright (C) 2019 Intel Corporation
+ * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/usb/pd_vdo.h>
+#include <linux/usb/typec_altmode.h>
+#include <linux/usb/typec_tbt.h>
+
+enum tbt_state {
+	TBT_STATE_IDLE,
+	TBT_STATE_SOP_P_ENTER,
+	TBT_STATE_SOP_PP_ENTER,
+	TBT_STATE_ENTER,
+	TBT_STATE_EXIT,
+	TBT_STATE_SOP_PP_EXIT,
+	TBT_STATE_SOP_P_EXIT
+};
+
+struct tbt_altmode {
+	enum tbt_state state;
+	struct typec_cable *cable;
+	struct typec_altmode *alt;
+	struct typec_altmode *plug[2];
+	u32 enter_vdo;
+
+	struct work_struct work;
+	struct mutex lock; /* device lock */
+};
+
+static bool tbt_ready(struct typec_altmode *alt);
+
+static int tbt_enter_mode(struct tbt_altmode *tbt)
+{
+	struct typec_altmode *plug = tbt->plug[TYPEC_PLUG_SOP_P];
+	u32 vdo;
+
+	vdo = tbt->alt->vdo & (TBT_VENDOR_SPECIFIC_B0 | TBT_VENDOR_SPECIFIC_B1);
+	vdo |= tbt->alt->vdo & TBT_INTEL_SPECIFIC_B0;
+	vdo |= TBT_MODE;
+
+	if (plug) {
+		if (typec_cable_is_active(tbt->cable))
+			vdo |= TBT_ENTER_MODE_ACTIVE_CABLE;
+
+		vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_SPEED(plug->vdo));
+		vdo |= plug->vdo & TBT_CABLE_ROUNDED;
+		vdo |= plug->vdo & TBT_CABLE_OPTICAL;
+		vdo |= plug->vdo & TBT_CABLE_RETIMER;
+		vdo |= plug->vdo & TBT_CABLE_LINK_TRAINING;
+	} else {
+		vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_USB3_PASSIVE);
+	}
+
+	tbt->enter_vdo = vdo;
+	return typec_altmode_enter(tbt->alt, &vdo);
+}
+
+static void tbt_altmode_work(struct work_struct *work)
+{
+	struct tbt_altmode *tbt = container_of(work, struct tbt_altmode, work);
+	int ret;
+
+	mutex_lock(&tbt->lock);
+
+	switch (tbt->state) {
+	case TBT_STATE_SOP_P_ENTER:
+		ret = typec_altmode_enter(tbt->plug[TYPEC_PLUG_SOP_P], NULL);
+		if (ret)
+			dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_P]->dev,
+				"failed to enter mode (%d)\n", ret);
+		break;
+	case TBT_STATE_SOP_PP_ENTER:
+		ret = typec_altmode_enter(tbt->plug[TYPEC_PLUG_SOP_PP], NULL);
+		if (ret)
+			dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_PP]->dev,
+				"failed to enter mode (%d)\n", ret);
+		break;
+	case TBT_STATE_ENTER:
+		ret = tbt_enter_mode(tbt);
+		if (ret)
+			dev_dbg(&tbt->alt->dev, "failed to enter mode (%d)\n",
+				ret);
+		break;
+	case TBT_STATE_EXIT:
+		typec_altmode_exit(tbt->alt);
+		break;
+	case TBT_STATE_SOP_PP_EXIT:
+		typec_altmode_exit(tbt->plug[TYPEC_PLUG_SOP_PP]);
+		break;
+	case TBT_STATE_SOP_P_EXIT:
+		typec_altmode_exit(tbt->plug[TYPEC_PLUG_SOP_P]);
+		break;
+	default:
+		break;
+	}
+
+	tbt->state = TBT_STATE_IDLE;
+
+	mutex_unlock(&tbt->lock);
+}
+
+static int tbt_altmode_vdm(struct typec_altmode *alt,
+			   const u32 hdr, const u32 *vdo, int count)
+{
+	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
+	int cmd_type = PD_VDO_CMDT(hdr);
+	int cmd = PD_VDO_CMD(hdr);
+
+	mutex_lock(&tbt->lock);
+
+	if (tbt->state != TBT_STATE_IDLE) {
+		mutex_unlock(&tbt->lock);
+		return -EBUSY;
+	}
+
+	switch (cmd_type) {
+	case CMDT_RSP_ACK:
+		switch (cmd) {
+		case CMD_ENTER_MODE:
+			/*
+			 * Following the order describeded in USB Type-C Spec
+			 * R2.0 Section 6.7.3.
+			 */
+			if (alt == tbt->plug[TYPEC_PLUG_SOP_P]) {
+				if (tbt->plug[TYPEC_PLUG_SOP_PP])
+					tbt->state = TBT_STATE_SOP_PP_ENTER;
+				else
+					tbt->state = TBT_STATE_ENTER;
+			} else if (alt == tbt->plug[TYPEC_PLUG_SOP_PP]) {
+				tbt->state = TBT_STATE_ENTER;
+			} else {
+				struct typec_thunderbolt_data data;
+
+				data.device_mode = tbt->alt->vdo;
+				data.cable_mode =
+					tbt->plug[TYPEC_PLUG_SOP_P] ?
+						tbt->plug[TYPEC_PLUG_SOP_P]
+							->vdo :
+						0;
+				data.enter_vdo = tbt->enter_vdo;
+
+				typec_altmode_notify(alt, TYPEC_STATE_MODAL, &data);
+			}
+			break;
+		case CMD_EXIT_MODE:
+			if (alt == tbt->alt) {
+				if (tbt->plug[TYPEC_PLUG_SOP_PP])
+					tbt->state = TBT_STATE_SOP_PP_EXIT;
+				else if (tbt->plug[TYPEC_PLUG_SOP_P])
+					tbt->state = TBT_STATE_SOP_P_EXIT;
+			} else if (alt == tbt->plug[TYPEC_PLUG_SOP_PP]) {
+				tbt->state = TBT_STATE_SOP_P_EXIT;
+			}
+			break;
+		}
+		break;
+	case CMDT_RSP_NAK:
+		switch (cmd) {
+		case CMD_ENTER_MODE:
+			dev_warn(&alt->dev, "Enter Mode refused\n");
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	if (tbt->state != TBT_STATE_IDLE)
+		schedule_work(&tbt->work);
+
+	mutex_unlock(&tbt->lock);
+
+	return 0;
+}
+
+static int tbt_altmode_activate(struct typec_altmode *alt, int activate)
+{
+	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
+	int ret;
+
+	mutex_lock(&tbt->lock);
+
+	if (!tbt_ready(alt))
+		return -ENODEV;
+
+	/* Preventing the user space from entering/exiting the cable alt mode */
+	if (alt != tbt->alt)
+		ret = -EPERM;
+	else if (activate)
+		ret = tbt_enter_mode(tbt);
+	else
+		ret = typec_altmode_exit(alt);
+
+	mutex_unlock(&tbt->lock);
+
+	return ret;
+}
+
+static const struct typec_altmode_ops tbt_altmode_ops = {
+	.vdm		= tbt_altmode_vdm,
+	.activate	= tbt_altmode_activate
+};
+
+static int tbt_altmode_probe(struct typec_altmode *alt)
+{
+	struct tbt_altmode *tbt;
+
+	tbt = devm_kzalloc(&alt->dev, sizeof(*tbt), GFP_KERNEL);
+	if (!tbt)
+		return -ENOMEM;
+
+	INIT_WORK(&tbt->work, tbt_altmode_work);
+	mutex_init(&tbt->lock);
+	tbt->alt = alt;
+
+	alt->desc = "Thunderbolt3";
+	typec_altmode_set_drvdata(alt, tbt);
+	typec_altmode_set_ops(alt, &tbt_altmode_ops);
+
+	if (tbt_ready(alt)) {
+		if (tbt->plug[TYPEC_PLUG_SOP_PP])
+			tbt->state = TBT_STATE_SOP_PP_ENTER;
+		else if (tbt->plug[TYPEC_PLUG_SOP_P])
+			tbt->state = TBT_STATE_SOP_P_ENTER;
+		else
+			tbt->state = TBT_STATE_ENTER;
+		schedule_work(&tbt->work);
+	}
+
+	return 0;
+}
+
+static void tbt_altmode_remove(struct typec_altmode *alt)
+{
+	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
+
+	for (int i = TYPEC_PLUG_SOP_PP; i > 0; --i) {
+		if (tbt->plug[i])
+			typec_altmode_put_plug(tbt->plug[i]);
+	}
+
+	if (tbt->cable)
+		typec_cable_put(tbt->cable);
+}
+
+static bool tbt_ready(struct typec_altmode *alt)
+{
+	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
+	struct typec_altmode *plug;
+
+	if (tbt->cable)
+		return true;
+
+	/* Thundebolt 3 requires a cable with eMarker */
+	tbt->cable = typec_cable_get(typec_altmode2port(tbt->alt));
+	if (!tbt->cable)
+		return false;
+
+	/* We accept systems without SOP' or SOP''. This means the port altmode
+	 * driver will be responsible for properly ordering entry/exit.
+	 */
+	for (int i = 0; i < TYPEC_PLUG_SOP_PP + 1; i++) {
+		plug = typec_altmode_get_plug(tbt->alt, i);
+		if (IS_ERR(plug))
+			continue;
+
+		if (!plug || plug->svid != USB_TYPEC_VENDOR_INTEL)
+			break;
+
+		plug->desc = "Thunderbolt3";
+		plug->ops = &tbt_altmode_ops;
+		typec_altmode_set_drvdata(plug, tbt);
+
+		tbt->plug[i] = plug;
+	}
+
+	return true;
+}
+
+static const struct typec_device_id tbt_typec_id[] = {
+	{ USB_TYPEC_TBT_SID },
+	{ }
+};
+MODULE_DEVICE_TABLE(typec, tbt_typec_id);
+
+static struct typec_altmode_driver tbt_altmode_driver = {
+	.id_table = tbt_typec_id,
+	.probe = tbt_altmode_probe,
+	.remove = tbt_altmode_remove,
+	.driver = {
+		.name = "typec-thunderbolt",
+		.owner = THIS_MODULE,
+	}
+};
+module_typec_altmode_driver(tbt_altmode_driver);
+
+MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Thunderbolt3 USB Type-C Alternate Mode");
diff --git a/include/linux/usb/typec_tbt.h b/include/linux/usb/typec_tbt.h
index fa97d7e00f5c..55dcea12082c 100644
--- a/include/linux/usb/typec_tbt.h
+++ b/include/linux/usb/typec_tbt.h
@@ -44,6 +44,7 @@  struct typec_thunderbolt_data {
 
 #define   TBT_GEN3_NON_ROUNDED                 0
 #define   TBT_GEN3_GEN4_ROUNDED_NON_ROUNDED    1
+#define TBT_CABLE_ROUNDED		BIT(19)
 #define TBT_CABLE_OPTICAL		BIT(21)
 #define TBT_CABLE_RETIMER		BIT(22)
 #define TBT_CABLE_LINK_TRAINING		BIT(23)