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[35.227.180.227]) by smtp.gmail.com with UTF8SMTPSA id 98e67ed59e1d1-2f2a1e9939fsm333523a91.13.2024.12.13.15.35.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 13 Dec 2024 15:35:56 -0800 (PST) From: Abhishek Pandit-Subedi To: heikki.krogerus@linux.intel.com, tzungbi@kernel.org, linux-usb@vger.kernel.org, chrome-platform@lists.linux.dev Cc: akuchynski@google.com, sboyd@kernel.org, pmalani@chromium.org, badhri@google.com, rdbabiera@google.com, dmitry.baryshkov@linaro.org, jthies@google.com, Abhishek Pandit-Subedi , Greg Kroah-Hartman , linux-kernel@vger.kernel.org Subject: [PATCH v5 2/8] usb: typec: Add driver for Thunderbolt 3 Alternate Mode Date: Fri, 13 Dec 2024 15:35:43 -0800 Message-ID: <20241213153543.v5.2.I3080b036e8de0b9957c57c1c3059db7149c5e549@changeid> X-Mailer: git-send-email 2.47.1.613.gc27f4b7a9f-goog In-Reply-To: <20241213233552.451927-1-abhishekpandit@chromium.org> References: <20241213233552.451927-1-abhishekpandit@chromium.org> Precedence: bulk X-Mailing-List: chrome-platform@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Heikki Krogerus Thunderbolt 3 Alternate Mode entry flow is described in USB Type-C Specification Release 2.0. Signed-off-by: Heikki Krogerus Co-developed-by: Abhishek Pandit-Subedi Signed-off-by: Abhishek Pandit-Subedi Reviewed-by: Benson Leung --- 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 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 + */ + +#include +#include +#include +#include +#include +#include +#include + +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 "); +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)