On Fri, Dec 13, 2024 at 03:35:43PM -0800, Abhishek Pandit-Subedi wrote: > From: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> > > Thunderbolt 3 Alternate Mode entry flow is described in > USB Type-C Specification Release 2.0. > > Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> > Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx> > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx> Reviewed-by: Benson Leung <bleung@xxxxxxxxxxxx> > --- > > Changes in v5: > - Add lockdep, missing includes and fix up block comment style. > > Changes in v4: > - Large refactor to use cable_altmodes > - Fixed ordering of cable mode enter/exit (SOP', SOP", then port for > enter; reverse order for exit) > - Other small fixes from v3 feedback > > 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 > > Changes in v1: > - 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)) > > drivers/usb/typec/altmodes/Kconfig | 9 + > drivers/usb/typec/altmodes/Makefile | 2 + > drivers/usb/typec/altmodes/thunderbolt.c | 388 +++++++++++++++++++++++ > include/linux/usb/typec_tbt.h | 1 + > 4 files changed, 400 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..1b475b1d98e7 > --- /dev/null > +++ b/drivers/usb/typec/altmodes/thunderbolt.c > @@ -0,0 +1,388 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * USB Typec-C Thunderbolt3 Alternate Mode driver > + * > + * Copyright (C) 2019 Intel Corporation > + * Author: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> > + */ > + > +#include <linux/lockdep.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/workqueue.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_cable_altmode_enter(tbt->alt, TYPEC_PLUG_SOP_P, NULL); > + if (ret) { > + dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_P]->dev, > + "failed to enter mode (%d)\n", ret); > + goto disable_plugs; > + } > + break; > + case TBT_STATE_SOP_PP_ENTER: > + ret = typec_cable_altmode_enter(tbt->alt, TYPEC_PLUG_SOP_PP, NULL); > + if (ret) { > + dev_dbg(&tbt->plug[TYPEC_PLUG_SOP_PP]->dev, > + "failed to enter mode (%d)\n", ret); > + goto disable_plugs; > + } > + 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_cable_altmode_exit(tbt->alt, TYPEC_PLUG_SOP_PP); > + break; > + case TBT_STATE_SOP_P_EXIT: > + typec_cable_altmode_exit(tbt->alt, TYPEC_PLUG_SOP_P); > + break; > + default: > + break; > + } > + > + tbt->state = TBT_STATE_IDLE; > + > + mutex_unlock(&tbt->lock); > + return; > + > +disable_plugs: > + for (int i = TYPEC_PLUG_SOP_PP; i > 0; --i) { > + if (tbt->plug[i]) > + typec_altmode_put_plug(tbt->plug[i]); > + > + tbt->plug[i] = NULL; > + } > + > + tbt->state = TBT_STATE_ENTER; > + schedule_work(&tbt->work); > + mutex_unlock(&tbt->lock); > +} > + > +/* > + * If SOP' is available, enter that first (which will trigger a VDM response > + * that will enter SOP" if available and then the port). If entering SOP' fails, > + * stop attempting to enter either cable altmode (probably not supported) and > + * directly enter the port altmode. > + */ > +static int tbt_enter_modes_ordered(struct typec_altmode *alt) > +{ > + struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt); > + int ret = 0; > + > + lockdep_assert_held(&tbt->lock); > + > + if (!tbt_ready(tbt->alt)) > + return -ENODEV; > + > + if (tbt->plug[TYPEC_PLUG_SOP_P]) { > + ret = typec_cable_altmode_enter(alt, TYPEC_PLUG_SOP_P, NULL); > + if (ret < 0) { > + for (int i = TYPEC_PLUG_SOP_PP; i > 0; --i) { > + if (tbt->plug[i]) > + typec_altmode_put_plug(tbt->plug[i]); > + > + tbt->plug[i] = NULL; > + } > + } else { > + return ret; > + } > + } > + > + return tbt_enter_mode(tbt); > +} > + > +static int tbt_cable_altmode_vdm(struct typec_altmode *alt, > + enum typec_plug_index sop, 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 described in USB Type-C Spec > + * R2.0 Section 6.7.3: SOP', SOP", then port. > + */ > + if (sop == 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 (sop == TYPEC_PLUG_SOP_PP) > + tbt->state = TBT_STATE_ENTER; > + > + break; > + case CMD_EXIT_MODE: > + /* Exit in opposite order: Port, SOP", then SOP'. */ > + if (sop == TYPEC_PLUG_SOP_PP) > + tbt->state = TBT_STATE_SOP_P_EXIT; > + break; > + } > + break; > + default: > + break; > + } > + > + if (tbt->state != TBT_STATE_IDLE) > + schedule_work(&tbt->work); > + > + mutex_unlock(&tbt->lock); > + return 0; > +} > + > +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); > + struct typec_thunderbolt_data data; > + 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: > + /* Port altmode is last to enter and first to exit. */ > + switch (cmd) { > + case CMD_ENTER_MODE: > + memset(&data, 0, sizeof(data)); > + > + data.device_mode = tbt->alt->vdo; > + data.enter_vdo = tbt->enter_vdo; > + if (tbt->plug[TYPEC_PLUG_SOP_P]) > + data.cable_mode = tbt->plug[TYPEC_PLUG_SOP_P]->vdo; > + > + typec_altmode_notify(alt, TYPEC_STATE_MODAL, &data); > + break; > + case CMD_EXIT_MODE: > + 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; > + 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 (activate) > + ret = tbt_enter_modes_ordered(alt); > + 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 const struct typec_cable_ops tbt_cable_ops = { > + .vdm = tbt_cable_altmode_vdm, > +}; > + > +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_P]) > + tbt->state = TBT_STATE_SOP_P_ENTER; > + else if (tbt->plug[TYPEC_PLUG_SOP_PP]) > + tbt->state = TBT_STATE_SOP_PP_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; > + > + /* Thunderbolt 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_TBT_SID) > + break; > + > + plug->desc = "Thunderbolt3"; > + plug->cable_ops = &tbt_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", > + } > +}; > +module_typec_altmode_driver(tbt_altmode_driver); > + > +MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>"); > +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) > -- > 2.47.1.613.gc27f4b7a9f-goog > >
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