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[34.127.75.226]) by smtp.gmail.com with UTF8SMTPSA id 41be03b00d2f7-7e6b7c3f161sm2912617a12.27.2024.09.25.09.25.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 25 Sep 2024 09:25:15 -0700 (PDT) From: Abhishek Pandit-Subedi To: heikki.krogerus@linux.intel.com, tzungbi@kernel.org Cc: jthies@google.com, pmalani@chromium.org, akuchynski@google.com, Abhishek Pandit-Subedi , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: [PATCH 1/8] usb: typec: Add driver for Thunderbolt 3 Alternate Mode Date: Wed, 25 Sep 2024 09:25:02 -0700 Message-ID: <20240925092505.1.I3080b036e8de0b9957c57c1c3059db7149c5e549@changeid> X-Mailer: git-send-email 2.46.0.792.g87dc391469-goog In-Reply-To: <20240925162513.435177-1-abhishekpandit@chromium.org> References: <20240925162513.435177-1-abhishekpandit@chromium.org> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org 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 Signed-off-by: Abhishek Pandit-Subedi --- 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. drivers/usb/typec/altmodes/Kconfig | 9 + drivers/usb/typec/altmodes/Makefile | 2 + drivers/usb/typec/altmodes/thunderbolt.c | 321 +++++++++++++++++++++++ 3 files changed, 332 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..515e775ee41a --- /dev/null +++ b/drivers/usb/typec/altmodes/thunderbolt.c @@ -0,0 +1,321 @@ +// SPDX-License-Identifier: GPL-2.0 +/** + * USB Typec-C Thuderbolt3 Alternate Mode driver + * + * Copyright (C) 2019 Intel Corporation + * Author: Heikki Krogerus + */ + +#include +#include +#include +#include +#include + +#define USB_TYPEC_VENDOR_INTEL 0x8087 + +/* TBT3 Device Discover Mode VDO bits */ +#define TBT_MODE BIT(0) +#define TBT_ADAPTER(_vdo_) (((_vdo_) & BIT(16)) >> 16) +#define TBT_ADAPTER_LEGACY 0 +#define TBT_ADAPTER_TBT3 1 +#define TBT_INTEL_SPECIFIC_B0 BIT(26) +#define TBT_VENDOR_SPECIFIC_B0 BIT(30) +#define TBT_VENDOR_SPECIFIC_B1 BIT(31) + +/* TBT3 Cable Discover Mode VDO bits */ +#define TBT_CABLE_SPEED(_vdo_) (((_vdo_) & GENMASK(18, 16)) >> 16) +#define TBT_CABLE_USB3_GEN1 1 +#define TBT_CABLE_USB3_PASSIVE 2 +#define TBT_CABLE_10_AND_20GBPS 3 +#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) + +/* TBT3 Device Enter Mode VDO bits */ +#define TBT_ENTER_MODE_CABLE_SPEED(_s_) (((_s_) & GENMASK(2, 0)) << 16) +#define TBT_ENTER_MODE_ACTIVE_CABLE BIT(24) + +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]; + + 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); + } + + 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 { + typec_altmode_notify(alt, TYPEC_STATE_MODAL, + NULL); + } + 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_VENDOR_INTEL, TYPEC_ANY_MODE }, + { } +}; +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 "); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Thunderbolt3 USB Type-C Alternate Mode");