From patchwork Sat Jan 14 09:32:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Badhri Jagan Sridharan X-Patchwork-Id: 13101920 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16B36C3DA78 for ; Sat, 14 Jan 2023 09:32:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229843AbjANJc6 (ORCPT ); Sat, 14 Jan 2023 04:32:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229947AbjANJcz (ORCPT ); Sat, 14 Jan 2023 04:32:55 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1087D6583 for ; Sat, 14 Jan 2023 01:32:51 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id x188-20020a2531c5000000b00716de19d76bso25570111ybx.19 for ; Sat, 14 Jan 2023 01:32:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=9mZBZpcFizd+zpHcl1R3Cd1un/Yz5/uAA1C9mtynnYA=; b=dbOUYZaTmjuRaeC/eOwwVVbY8fx67okDmvyMeMYXtaKqScsxIi8qpW5zQM/+x4F0YS RuZ0iBOHF2ZZWVEGsyX2mEgMgaZ9latc6NkGiokGf95S5WOsqc213XnEBGsfd2mNIGc7 bSn5VSJ1AGDMZ6QVV1VMumvEVCS1QnX6i3qSMtzaocv80yLNLY6ddnSVQdz7GA7+Y6pE L3ICnyrqZ7AtqHDRk5pXIP0LvD9gxM2HkL0VXZyz0++EpyGFOlOhWh/MGvB839xU1E0G f6X7IyspQ/wR7W6sPxg8KEHxeyRbfPHArQ4CyMSEs2aneTlMg5SWDfZjOu/8Iek/IZ3b mkNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=9mZBZpcFizd+zpHcl1R3Cd1un/Yz5/uAA1C9mtynnYA=; b=m5zB6rJxMN1Qm7hkWlYC/SA/I4DwfN4/+fysNP5I4oHoBrQC4yy+HHliSFgWH9oykK Aic7asxv64OLnDvtNha6m2pDlIznMIdv3S0rEAblDKmquEFZ0sWi1+bDh+QN8lglWI3L v9eO/4SbVIFHAse/7O4tQQFsiZYcRkmv6xGQHLbi6NQx13x21DGpdacKiCCDiDQTNYwS cFBj6ECDUXGZR9Fj7bzUWFsZcpwbqE2Wa+FX1/I7DyB0tzZ4e+NipvOjSB3GbQ7UMB+3 qFwUcd8PNuJUg5LD94avbaTf/3Gj/lYScxpc9+c3g2YdD8fZxcjoe6thAz8t+zdpTJpy Zo8g== X-Gm-Message-State: AFqh2kpqQq12chx3ycSL06bEHa9Ta+EvLMyEQRy6d2vuu83UbYYnSE9d dLqcsjmssGgfI1oe8rkNunFjtzvnoSA= X-Google-Smtp-Source: AMrXdXvFHVx3fEiPGSxDhbP8av0tyLHUFFwL64VrYeTOau2cfytSwqhZtEvDRpb4kaS5R2LhS7muQ2B5fi0= X-Received: from badhri.mtv.corp.google.com ([2620:15c:211:201:d726:232e:7cc0:6434]) (user=badhri job=sendgmr) by 2002:a0d:cb41:0:b0:4d9:36f4:2221 with SMTP id n62-20020a0dcb41000000b004d936f42221mr1191036ywd.6.1673688770365; Sat, 14 Jan 2023 01:32:50 -0800 (PST) Date: Sat, 14 Jan 2023 01:32:44 -0800 Mime-Version: 1.0 X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog Message-ID: <20230114093246.1933321-1-badhri@google.com> Subject: [PATCH v13 1/3] usb: typec: tcpm: Add callbacks to mitigate wakeups due to contaminant From: Badhri Jagan Sridharan To: Guenter Roeck , Heikki Krogerus , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Kyle Tso , Badhri Jagan Sridharan Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On some of the TCPC implementations, when the Type-C port is exposed to contaminants, such as water, TCPC stops toggling while reporting OPEN either by the time TCPM reads CC pin status or during CC debounce window. This causes TCPM to be stuck in TOGGLING state. If TCPM is made to restart toggling, the behavior recurs causing redundant CPU wakeups till the USB-C port is free of contaminant. [206199.287817] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected] [206199.640337] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected] [206199.985789] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected] (or) [ 7853.867577] Start toggling [ 7853.889921] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected] [ 7855.698765] CC1: 0 -> 0, CC2: 0 -> 5 [state TOGGLING, polarity 0, connected] [ 7855.698790] state change TOGGLING -> SNK_ATTACH_WAIT [rev3 NONE_AMS] [ 7855.698826] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev3 NONE_AMS] [ 7855.703559] CC1: 0 -> 0, CC2: 5 -> 5 [state SNK_ATTACH_WAIT, polarity 0, connected] [ 7855.856555] CC1: 0 -> 0, CC2: 5 -> 0 [state SNK_ATTACH_WAIT, polarity 0, disconnected] [ 7855.856581] state change SNK_ATTACH_WAIT -> SNK_ATTACH_WAIT [rev3 NONE_AMS] [ 7855.856613] pending state change SNK_ATTACH_WAIT -> SNK_UNATTACHED @ 170 ms [rev3 NONE_AMS] [ 7856.027744] state change SNK_ATTACH_WAIT -> SNK_UNATTACHED [delayed 170 ms] [ 7856.181949] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected] [ 7856.187896] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected] [ 7857.645630] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected] [ 7857.647291] CC1: 0 -> 0, CC2: 0 -> 5 [state TOGGLING, polarity 0, connected] [ 7857.647298] state change TOGGLING -> SNK_ATTACH_WAIT [rev3 NONE_AMS] [ 7857.647310] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev3 NONE_AMS] [ 7857.808106] CC1: 0 -> 0, CC2: 5 -> 0 [state SNK_ATTACH_WAIT, polarity 0, disconnected] [ 7857.808123] state change SNK_ATTACH_WAIT -> SNK_ATTACH_WAIT [rev3 NONE_AMS] [ 7857.808150] pending state change SNK_ATTACH_WAIT -> SNK_UNATTACHED @ 170 ms [rev3 NONE_AMS] [ 7857.978727] state change SNK_ATTACH_WAIT -> SNK_UNATTACHED [delayed 170 ms] To mitigate redundant TCPM wakeups, TCPCs which do have the needed hardware can implement the check_contaminant callback which is invoked by TCPM to evaluate for presence of contaminant. Lower level TCPC driver can restart toggling through TCPM_PORT_CLEAN event when the driver detects that USB-C port is free of contaminant. check_contaminant callback also passes the disconnect_while_debounce flag which when true denotes that the CC pins transitioned to OPEN state during the CC debounce window. Signed-off-by: Badhri Jagan Sridharan Acked-by: Heikki Krogerus --- Changes since v12: * None. Changes since v11: * None. Changes since v10: * Fall back to default state if enabling toggling fails when * exiting CHECK_CONTAMINANT state Changes since v9: * Invoke tcpm_start_toggling before transitioning to TOGGLING from * CHECK_CONTAMINANT. Changes since v7: * None. Skipped versions by mistake. Changes since v6: * folded the debounce logic into tcpm state machine and removed tcpm * state export. * Added a helper to determine whether the port is in toggling state. * Excluded CHECK_CONTAMINANT from tcpm_log. Changes since v5: * Updated commit message. Removed change id. Changes since v4: * None Changes since v3: * None Changes since V2: * Offloaded tcpm from maintaining disconnect_while_debouncing logic * to lower level maxim tcpc driver based on feedback. --- drivers/usb/typec/tcpm/tcpm.c | 55 ++++++++++++++++++++++++++++++++++- include/linux/usb/tcpm.h | 8 +++++ 2 files changed, 62 insertions(+), 1 deletion(-) diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index 904c7b4ce2f0..c624747f32df 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -36,6 +36,7 @@ #define FOREACH_STATE(S) \ S(INVALID_STATE), \ S(TOGGLING), \ + S(CHECK_CONTAMINANT), \ S(SRC_UNATTACHED), \ S(SRC_ATTACH_WAIT), \ S(SRC_ATTACHED), \ @@ -249,6 +250,7 @@ enum frs_typec_current { #define TCPM_RESET_EVENT BIT(2) #define TCPM_FRS_EVENT BIT(3) #define TCPM_SOURCING_VBUS BIT(4) +#define TCPM_PORT_CLEAN BIT(5) #define LOG_BUFFER_ENTRIES 1024 #define LOG_BUFFER_ENTRY_SIZE 128 @@ -483,6 +485,13 @@ struct tcpm_port { * SNK_READY for non-pd link. */ bool slow_charger_loop; + + /* + * When true indicates that the lower level drivers indicate potential presence + * of contaminant in the connector pins based on the tcpm state machine + * transitions. + */ + bool potential_contaminant; #ifdef CONFIG_DEBUG_FS struct dentry *dentry; struct mutex logbuffer_lock; /* log buffer access lock */ @@ -647,7 +656,7 @@ static void tcpm_log(struct tcpm_port *port, const char *fmt, ...) /* Do not log while disconnected and unattached */ if (tcpm_port_is_disconnected(port) && (port->state == SRC_UNATTACHED || port->state == SNK_UNATTACHED || - port->state == TOGGLING)) + port->state == TOGGLING || port->state == CHECK_CONTAMINANT)) return; va_start(args, fmt); @@ -3904,15 +3913,28 @@ static void run_state_machine(struct tcpm_port *port) unsigned int msecs; enum tcpm_state upcoming_state; + if (port->tcpc->check_contaminant && port->state != CHECK_CONTAMINANT) + port->potential_contaminant = ((port->enter_state == SRC_ATTACH_WAIT && + port->state == SRC_UNATTACHED) || + (port->enter_state == SNK_ATTACH_WAIT && + port->state == SNK_UNATTACHED)); + port->enter_state = port->state; switch (port->state) { case TOGGLING: break; + case CHECK_CONTAMINANT: + port->tcpc->check_contaminant(port->tcpc); + break; /* SRC states */ case SRC_UNATTACHED: if (!port->non_pd_role_swap) tcpm_swap_complete(port, -ENOTCONN); tcpm_src_detach(port); + if (port->potential_contaminant) { + tcpm_set_state(port, CHECK_CONTAMINANT, 0); + break; + } if (tcpm_start_toggling(port, tcpm_rp_cc(port))) { tcpm_set_state(port, TOGGLING, 0); break; @@ -4150,6 +4172,10 @@ static void run_state_machine(struct tcpm_port *port) tcpm_swap_complete(port, -ENOTCONN); tcpm_pps_complete(port, -ENOTCONN); tcpm_snk_detach(port); + if (port->potential_contaminant) { + tcpm_set_state(port, CHECK_CONTAMINANT, 0); + break; + } if (tcpm_start_toggling(port, TYPEC_CC_RD)) { tcpm_set_state(port, TOGGLING, 0); break; @@ -4926,6 +4952,9 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1, else if (tcpm_port_is_sink(port)) tcpm_set_state(port, SNK_ATTACH_WAIT, 0); break; + case CHECK_CONTAMINANT: + /* Wait for Toggling to be resumed */ + break; case SRC_UNATTACHED: case ACC_UNATTACHED: if (tcpm_port_is_debug(port) || tcpm_port_is_audio(port) || @@ -5425,6 +5454,15 @@ static void tcpm_pd_event_handler(struct kthread_work *work) port->vbus_source = true; _tcpm_pd_vbus_on(port); } + if (events & TCPM_PORT_CLEAN) { + tcpm_log(port, "port clean"); + if (port->state == CHECK_CONTAMINANT) { + if (tcpm_start_toggling(port, tcpm_rp_cc(port))) + tcpm_set_state(port, TOGGLING, 0); + else + tcpm_set_state(port, tcpm_default_state(port), 0); + } + } spin_lock(&port->pd_event_lock); } @@ -5477,6 +5515,21 @@ void tcpm_sourcing_vbus(struct tcpm_port *port) } EXPORT_SYMBOL_GPL(tcpm_sourcing_vbus); +void tcpm_port_clean(struct tcpm_port *port) +{ + spin_lock(&port->pd_event_lock); + port->pd_events |= TCPM_PORT_CLEAN; + spin_unlock(&port->pd_event_lock); + kthread_queue_work(port->wq, &port->event_work); +} +EXPORT_SYMBOL_GPL(tcpm_port_clean); + +bool tcpm_port_is_toggling(struct tcpm_port *port) +{ + return port->port_type == TYPEC_PORT_DRP && port->state == TOGGLING; +} +EXPORT_SYMBOL_GPL(tcpm_port_is_toggling); + static void tcpm_enable_frs_work(struct kthread_work *work) { struct tcpm_port *port = container_of(work, struct tcpm_port, enable_frs); diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h index bffc8d3e14ad..ab7ca872950b 100644 --- a/include/linux/usb/tcpm.h +++ b/include/linux/usb/tcpm.h @@ -114,6 +114,11 @@ enum tcpm_transmit_type { * Optional; The USB Communications Capable bit indicates if port * partner is capable of communication over the USB data lines * (e.g. D+/- or SS Tx/Rx). Called to notify the status of the bit. + * @check_contaminant: + * Optional; The callback is called when CC pins report open status + * at the end of the deboumce period or when the port is still + * toggling. Chip level drivers are expected to check for contaminant + * and call tcpm_clean_port when the port is clean. */ struct tcpc_dev { struct fwnode_handle *fwnode; @@ -148,6 +153,7 @@ struct tcpc_dev { bool pps_active, u32 requested_vbus_voltage); bool (*is_vbus_vsafe0v)(struct tcpc_dev *dev); void (*set_partner_usb_comm_capable)(struct tcpc_dev *dev, bool enable); + void (*check_contaminant)(struct tcpc_dev *dev); }; struct tcpm_port; @@ -165,5 +171,7 @@ void tcpm_pd_transmit_complete(struct tcpm_port *port, enum tcpm_transmit_status status); void tcpm_pd_hard_reset(struct tcpm_port *port); void tcpm_tcpc_reset(struct tcpm_port *port); +void tcpm_port_clean(struct tcpm_port *port); +bool tcpm_port_is_toggling(struct tcpm_port *port); #endif /* __LINUX_USB_TCPM_H */