From patchwork Tue Sep 29 02:40:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Badhri Jagan Sridharan X-Patchwork-Id: 11804857 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BEC16618 for ; Tue, 29 Sep 2020 02:40:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9975521531 for ; Tue, 29 Sep 2020 02:40:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="AN7jGW4h" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727617AbgI2Ck5 (ORCPT ); Mon, 28 Sep 2020 22:40:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727441AbgI2Ckh (ORCPT ); Mon, 28 Sep 2020 22:40:37 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E239FC0613D3 for ; Mon, 28 Sep 2020 19:40:36 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id k3so3269492ybk.16 for ; Mon, 28 Sep 2020 19:40:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=7BBWEe/m6+JsmjTQaxa4gKxB4RV5Mm1tFRx7FLpn8z0=; b=AN7jGW4hgtrN2OFSD0c3QWaNeXP837vSaKq4g8PRwc5JofpbMOFwmr4a/WOAkDZQMA Q73Reax2JZ4U2giSgud6hhJjxNhpDSycAqCsFS6ALymlCbLrfMATCt+c3VEHj6LQ63Xd 6SeVXMkh0v1d+bcVzlx8zNr25L8H20YBezWC8hNU1TdZiBFWH6dYJxOixKi1+jk4pnjP sfQf59iHX4opDoZ2ornVjtSxa22CEpz7wQruH0e3HRBNzvYJ+7GHOqwPmyxoD5ZSOZRa kqf9tIsL+SEJCRE73Cp4JgD2yVwgZSILP5ZAARWS1wArMiID5vHqo278TpMGwOgnBv3M k77A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=7BBWEe/m6+JsmjTQaxa4gKxB4RV5Mm1tFRx7FLpn8z0=; b=DEgNjz10keUtYOv2jpZJBnDu5KY4s18V3pmWU27uc84Oc3scCcP70ACF0Z+zQuy8eL e0P5TKBHTRT9kfwtXyOPj6HJ5UTyEu0YBET/EZjdlOkmQngH8NjWacccKAtgZ2H8pVSb WKA/2K94pEx/B3MDWCmiWQDEZUqK95wfeon25ilu8+r/GuaKZMwx0OmnVN1ARo7B3U5w zIyi4aFQGA4fNacpaw1NtOsHVcfgfBpAXk4tUwFuu1zXGxgEungpyxRp/Euvm0wI/1qJ 48h/wLUoeydTmtQyb1+ssNnaHZ5sf5GdKr0Rl95PJnY0ValptMZ4B2h6lSpd0MksKq6z aSeA== X-Gm-Message-State: AOAM532O5hog9QSVEqkdNhpRkJenYxBe8ANSYRt/4j0j8mgWF5/cpGOh 3DLH+v6ln75Zc9fMq/dZQ8eqTJ2Gta8= X-Google-Smtp-Source: ABdhPJyMJ9lnJjHbRfUQ2gIrnfQvQ9JerVsOiNzzGOPIXh148QJPCFJ8hBYWpxHE1glkBnXs+9FVKf3pBoM= Sender: "badhri via sendgmr" X-Received: from badhri.mtv.corp.google.com ([2620:15c:211:1:f292:1cff:fee0:66cf]) (user=badhri job=sendgmr) by 2002:a25:d950:: with SMTP id q77mr3541624ybg.402.1601347236072; Mon, 28 Sep 2020 19:40:36 -0700 (PDT) Date: Mon, 28 Sep 2020 19:40:02 -0700 In-Reply-To: <20200929024004.244992-1-badhri@google.com> Message-Id: <20200929024004.244992-14-badhri@google.com> Mime-Version: 1.0 References: <20200929024004.244992-1-badhri@google.com> X-Mailer: git-send-email 2.28.0.709.gb0816b6eb0-goog Subject: [PATCH v9 13/15] usb: typec: tcpm: Implement enabling Auto Discharge disconnect support From: Badhri Jagan Sridharan To: Guenter Roeck , Heikki Krogerus , Greg Kroah-Hartman , Rob Herring , Lee Jones , Mark Brown , Maxime Ripard , Alexandre Belloni , Thierry Reding , Prashant Malani , Badhri Jagan Sridharan Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org TCPCI spec allows TCPC hardware to autonomously discharge the vbus capacitance upon disconnect. The expectation is that the TCPM enables AutoDischargeDisconnect while entering SNK/SRC_ATTACHED states. Hardware then automously discharges vbus when the vbus falls below a certain threshold i.e. VBUS_SINK_DISCONNECT_THRESHOLD. Apart from enabling the vbus discharge circuit, AutoDischargeDisconnect is also used a flag to move TCPCI based TCPC implementations into Attached.Snk/Attached.Src state as mentioned in Figure 4-15. TCPC State Diagram before a Connection of the USB Type-C Port Controller Interface Specification. In such TCPC implementations, setting AutoDischargeDisconnect would prevent TCPC into entering "Connection_Invalid" state as well. Signed-off-by: Badhri Jagan Sridharan --- Changes since v1: - Changing patch version to v6 to fix version number confusion. Changes since v6: - Fixed incorrect data_role error that I introduced by mistake in the previous version. Changes since v7: - Rebase on usb-next Changes since v8: - Removing the call to tcpm_set_auto_vbus_discharge_threshold in the source path. --- drivers/usb/typec/tcpm/tcpm.c | 60 ++++++++++++++++++++++++++++++++--- include/linux/usb/tcpm.h | 15 +++++++++ 2 files changed, 71 insertions(+), 4 deletions(-) diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index d5a3e2b3bea2..51a14d282109 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -1701,6 +1701,24 @@ static void tcpm_handle_alert(struct tcpm_port *port, const __le32 *payload, } } +static int tcpm_set_auto_vbus_discharge_threshold(struct tcpm_port *port, + enum typec_pwr_opmode mode, bool pps_active, + u32 requested_vbus_voltage) +{ + int ret; + + if (!port->tcpc->set_auto_vbus_discharge_threshold) + return 0; + + ret = port->tcpc->set_auto_vbus_discharge_threshold(port->tcpc, mode, pps_active, + requested_vbus_voltage); + tcpm_log_force(port, + "set_auto_vbus_discharge_threshold mode:%d pps_active:%c vbus:%u ret:%d", + mode, pps_active ? 'y' : 'n', requested_vbus_voltage, ret); + + return ret; +} + static void tcpm_pd_data_request(struct tcpm_port *port, const struct pd_message *msg) { @@ -1871,6 +1889,10 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, port->current_limit, port->supply_voltage); port->explicit_contract = true; + tcpm_set_auto_vbus_discharge_threshold(port, + TYPEC_PWR_MODE_PD, + port->pps_data.active, + port->supply_voltage); tcpm_set_state(port, SNK_READY, 0); } else { /* @@ -2785,8 +2807,12 @@ static int tcpm_src_attach(struct tcpm_port *port) if (ret < 0) return ret; - ret = tcpm_set_roles(port, true, TYPEC_SOURCE, - tcpm_data_role_for_source(port)); + if (port->tcpc->enable_auto_vbus_discharge) { + ret = port->tcpc->enable_auto_vbus_discharge(port->tcpc, true); + tcpm_log_force(port, "enable vbus discharge ret:%d", ret); + } + + ret = tcpm_set_roles(port, true, TYPEC_SOURCE, tcpm_data_role_for_source(port)); if (ret < 0) return ret; @@ -2853,6 +2879,12 @@ static void tcpm_unregister_altmodes(struct tcpm_port *port) static void tcpm_reset_port(struct tcpm_port *port) { + int ret; + + if (port->tcpc->enable_auto_vbus_discharge) { + ret = port->tcpc->enable_auto_vbus_discharge(port->tcpc, false); + tcpm_log_force(port, "Disable vbus discharge ret:%d", ret); + } tcpm_unregister_altmodes(port); tcpm_typec_disconnect(port); port->attached = false; @@ -2917,8 +2949,13 @@ static int tcpm_snk_attach(struct tcpm_port *port) if (ret < 0) return ret; - ret = tcpm_set_roles(port, true, TYPEC_SINK, - tcpm_data_role_for_sink(port)); + if (port->tcpc->enable_auto_vbus_discharge) { + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, VSAFE5V); + ret = port->tcpc->enable_auto_vbus_discharge(port->tcpc, true); + tcpm_log_force(port, "enable vbus discharge ret:%d", ret); + } + + ret = tcpm_set_roles(port, true, TYPEC_SINK, tcpm_data_role_for_sink(port)); if (ret < 0) return ret; @@ -3502,6 +3539,8 @@ static void run_state_machine(struct tcpm_port *port) tcpm_set_state(port, SRC_UNATTACHED, PD_T_PS_SOURCE_ON); break; case SNK_HARD_RESET_SINK_OFF: + /* Do not discharge/disconnect during hard reseet */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, 0); memset(&port->pps_data, 0, sizeof(port->pps_data)); tcpm_set_vconn(port, false); if (port->pd_capable) @@ -3544,6 +3583,7 @@ static void run_state_machine(struct tcpm_port *port) tcpm_set_charge(port, true); } tcpm_set_attached_state(port, true); + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, VSAFE5V); tcpm_set_state(port, SNK_STARTUP, 0); break; @@ -3645,6 +3685,10 @@ static void run_state_machine(struct tcpm_port *port) tcpm_set_state(port, PR_SWAP_SNK_SRC_SINK_OFF, 0); break; case PR_SWAP_SRC_SNK_TRANSITION_OFF: + /* + * Prevent vbus discharge circuit from turning on during PR_SWAP + * as this is not a disconnect. + */ tcpm_set_vbus(port, false); port->explicit_contract = false; /* allow time for Vbus discharge, must be < tSrcSwapStdby */ @@ -3673,9 +3717,17 @@ static void run_state_machine(struct tcpm_port *port) tcpm_set_state_cond(port, SNK_UNATTACHED, PD_T_PS_SOURCE_ON); break; case PR_SWAP_SRC_SNK_SINK_ON: + /* Set the vbus disconnect threshold for implicit contract */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, VSAFE5V); tcpm_set_state(port, SNK_STARTUP, 0); break; case PR_SWAP_SNK_SRC_SINK_OFF: + /* + * Prevent vbus discharge circuit from turning on during PR_SWAP + * as this is not a disconnect. + */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, + port->pps_data.active, 0); tcpm_set_charge(port, false); tcpm_set_state(port, hard_reset_state(port), PD_T_PS_SOURCE_OFF); diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h index 7303f518ba49..e68aaa12886f 100644 --- a/include/linux/usb/tcpm.h +++ b/include/linux/usb/tcpm.h @@ -86,6 +86,18 @@ enum tcpm_transmit_type { * @frs_sourcing_vbus: * Optional; Called to notify that vbus is now being sourced. * Low level drivers can perform chip specific operations, if any. + * @enable_auto_vbus_discharge: + * Optional; TCPCI spec based TCPC implementations can optionally + * support hardware to autonomously dischrge vbus upon disconnecting + * as sink or source. TCPM signals TCPC to enable the mechanism upon + * entering connected state and signals disabling upon disconnect. + * @set_auto_vbus_discharge_threshold: + * Mandatory when enable_auto_vbus_discharge is implemented. TCPM + * calls this function to allow lower levels drivers to program the + * vbus threshold voltage below which the vbus discharge circuit + * will be turned on. requested_vbus_voltage is set to 0 when vbus + * is going to disappear knowingly i.e. during PR_SWAP and + * HARD_RESET etc. */ struct tcpc_dev { struct fwnode_handle *fwnode; @@ -113,6 +125,9 @@ struct tcpc_dev { int (*set_bist_data)(struct tcpc_dev *dev, bool on); int (*enable_frs)(struct tcpc_dev *dev, bool enable); void (*frs_sourcing_vbus)(struct tcpc_dev *dev); + int (*enable_auto_vbus_discharge)(struct tcpc_dev *dev, bool enable); + int (*set_auto_vbus_discharge_threshold)(struct tcpc_dev *dev, enum typec_pwr_opmode mode, + bool pps_active, u32 requested_vbus_voltage); }; struct tcpm_port;