From patchwork Thu Oct 8 06:15:54 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: 11822215 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 02F10139F for ; Thu, 8 Oct 2020 06:16:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D349620760 for ; Thu, 8 Oct 2020 06:16:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="mNMAOTdU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728851AbgJHGQj (ORCPT ); Thu, 8 Oct 2020 02:16:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728412AbgJHGQi (ORCPT ); Thu, 8 Oct 2020 02:16:38 -0400 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 0FB1BC0613E2 for ; Wed, 7 Oct 2020 23:16:30 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id v4so203370ybp.3 for ; Wed, 07 Oct 2020 23:16:30 -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=GjCc+BQkNqKSsKaA/WplKUyBVW0UGrqMAZUqUladaLM=; b=mNMAOTdUE549pA1vBLa0xlJl2DtepK4ZRhiLM0QF82FkDuuyDMHjtOyDdYrY9DNHtK oaEVZ53iAMGaUt8Pgp0PRKucNYmejbhR2AAMK50NC+W9D9ogB7hvNj1UmBZAMeAhgiPB 1asuQEZiPBJyrkkD4eg9V0K4jGraGxlidw0RFZA8eXdnYIIL2lSm7ZD0MyVJaPLyGarq 9/je4jc1vJ5ZkMyoup0Ph6Oj+DVsG2IngP4zXGN7+NDAglskG6FiwO8neTxTsdKZO7GO EmQwBwcEY1cMH4unzzc36st1ax5FRhaWXNWdkBjKq8TUj17RUll/H3LYtPLqbKgZSmnp d4tw== 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=GjCc+BQkNqKSsKaA/WplKUyBVW0UGrqMAZUqUladaLM=; b=dOYS+cqDfQj+FEcPmbFS2HElAKLy+3W+uXm3ict3zN4O3b6EDYe7oIMFfcGVIfOvI5 3jYVBtKA4G06D+AnjIFc9hpQfx3Y2NcHBZHddjfoVSqI/8mUt3wStv20ZC1Kest6suaJ zzZntgB+hQAdzbQ9IEwsl/GZvI2b9yf5ZZttjsoUTAlnSMpB8gh3KBp8038BkbzHgXge 7TdvfzMYags8nRFtQe3QLNoGKjeD4t3zLsD4M3m5uQllBTgg1mVklvGWT5LywIRM80gh Qy0vQ61I7sNEVYJNwGAs6qda+AaGjDYlnSDyPcWjb7ir//5TtOO+FQ0JYkeqvngf6nIM kNFg== X-Gm-Message-State: AOAM5334EK/zMq2M7nrw8UZXQlX4QKTo/Z8+17SLA+VPJd5xD4LvM2yP EtuuLHRpjcrjCiJ8HCmlfM+xoHqt1iI= X-Google-Smtp-Source: ABdhPJzw4x4l4Msd/pS1Y6RiCAeIrWU4Iz05D1UDL3YFVodLdqhIcGiLm6uyT/nuVvEkqP5oiunssN376wQ= 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:a290:: with SMTP id c16mr9189840ybi.84.1602137789208; Wed, 07 Oct 2020 23:16:29 -0700 (PDT) Date: Wed, 7 Oct 2020 23:15:54 -0700 In-Reply-To: <20201008061556.1402293-1-badhri@google.com> Message-Id: <20201008061556.1402293-14-badhri@google.com> Mime-Version: 1.0 References: <20201008061556.1402293-1-badhri@google.com> X-Mailer: git-send-email 2.28.0.806.g8561365e88-goog Subject: [PATCH v10 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, Amelie Delaunay 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 Reviewed-by: Heikki Krogerus --- 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. - Changes since v9: - None --- 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;