From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B66DAC43461 for ; Wed, 14 Apr 2021 02:40:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 87887613CC for ; Wed, 14 Apr 2021 02:40:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345821AbhDNCkd (ORCPT ); Tue, 13 Apr 2021 22:40:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343790AbhDNCk2 (ORCPT ); Tue, 13 Apr 2021 22:40:28 -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 C800DC06138D for ; Tue, 13 Apr 2021 19:40:07 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id p68so11709095ybg.20 for ; Tue, 13 Apr 2021 19:40:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=zITHXmYSEGrpR+08cIDRIpeKXQIvom7Nfxqoy64vyVU=; b=C1p05V8aXy0pUNoTlGHaPYXjPdNLHBzel2rlneXFncHcWnkOvSdECMtDQ3AQ682zD7 X/6FxFdlQa3fVGrePXOfP8vqSM3xAZGdvEqCMmICSeLh/TmVwu3+exKCgKliDUNIeHzE /ZXHoCc6cxMD4n1NRrrjCUVRabA7zJnq/bTI/MmWNrbBbZeZkK5rQu9dxu4fHb/ALIFc w5J5GZeJ8SmsN8r/TxPC1SBkaqBM5Eyxr47lLF5OlH7zUK5YY8c7IlY+AdTccXhmvXKD jYPwja3I2+OCtDSP4j/J3Cuztv69uKG7r+fgZo/n78C5JVpIAjmhArq1e3DhS8aLZyfv MXRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=zITHXmYSEGrpR+08cIDRIpeKXQIvom7Nfxqoy64vyVU=; b=MLuWfyyzBMBzPGUoT2zMuv9tOXlwTLtgCctZ4Hbnid+vurayIpNUjexY1f96HG7DvS 4flP1DVdzpZvCbIDkWx7KnIKxlZK1fqn8SiVMPdduEySxkYZYxhtOxu/ZXeMylghwh9z +eGzA4thU6qWdzpZqvRI1O6m8ghExoH/hXZTlTiMAlIN6Brmh5BPAriyrwvnYGM94vOs 7e67pjhtPCnXVIvR413V/6mt6zoPmvMB288mnU9pE/SdbvIChDQAW30Jm16wvFlTmi6V s/LgbMFc2Amph3O5XSCZ8C+odlOg9Fp+7DhXu3/MqE0oFrCXuM6FJKJAws3LwHPYgsPF zV2A== X-Gm-Message-State: AOAM531FjJOPTnBhc5ydNykMYGmmbLzAI1xvLJFyHrc1KBG8CaqOF9MH BBdwqB+J6Kn+qas3GXBebSbp3dnZIlg= X-Google-Smtp-Source: ABdhPJzefCYV5RXeI1VVZejUFS4/Tj7hrJeXqx6rLWZBPHyUW2YanGEB8xs/PP2eljYU+4K1f38RrBF4+R8= X-Received: from badhri.mtv.corp.google.com ([2620:15c:211:201:91dd:58ac:7590:aa21]) (user=badhri job=sendgmr) by 2002:a25:d181:: with SMTP id i123mr26623226ybg.387.1618368007045; Tue, 13 Apr 2021 19:40:07 -0700 (PDT) Date: Tue, 13 Apr 2021 19:39:59 -0700 In-Reply-To: <20210414024000.4175263-1-badhri@google.com> Message-Id: <20210414024000.4175263-2-badhri@google.com> Mime-Version: 1.0 References: <20210414024000.4175263-1-badhri@google.com> X-Mailer: git-send-email 2.31.1.295.g9ea45b61b8-goog Subject: [PATCH v3 2/3] usb: typec: tcpm: Allow slow charging loops to comply to pSnkStby From: Badhri Jagan Sridharan To: Guenter Roeck , Heikki Krogerus , Greg Kroah-Hartman , Rob Herring , Adam Thomson Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Kyle Tso , Badhri Jagan Sridharan Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When a PD charger advertising Rp-3.0 is connected to a sink port, the sink port current limit would 3A, during SNK_DISCOVERY, till power negotiation starts. Once the negotiation starts the power limit needs to drop down to pSnkStby(500mA @ 5V) and to negotiated current limit once the explicit contract is in place. Not all charging loops can ramp up to 3A and drop down to 500mA within tSnkStdby which is 15ms. The port partner might hard reset if tSnkStdby is not met. To solve this problem, this patch introduces slow-charger-loop which when set makes the port request PD_P_SNK_STDBY_MW upon entering SNK_DISCOVERY(instead of 3A or the 1.5A during SNK_DISCOVERY) and the actual currrent limit after RX of PD_CTRL_PSRDY for PD link or during SNK_READY for non-pd link. Signed-off-by: Badhri Jagan Sridharan --- Changes since V2: * Refactored code based on Heikki's suggestion --- drivers/usb/typec/tcpm/tcpm.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index aedc8bb9532a..2ad5e14a6867 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -459,6 +459,12 @@ struct tcpm_port { /* Auto vbus discharge status */ bool auto_vbus_discharge_enabled; + /* + * When set, port requests PD_P_SNK_STDBY_MW upon entering SNK_DISCOVERY and + * the actual currrent limit after RX of PD_CTRL_PSRDY for PD link, + * SNK_READY for non-pd link. + */ + bool slow_charger_loop; #ifdef CONFIG_DEBUG_FS struct dentry *dentry; struct mutex logbuffer_lock; /* log buffer access lock */ @@ -4047,9 +4053,11 @@ static void run_state_machine(struct tcpm_port *port) break; case SNK_DISCOVERY: if (port->vbus_present) { - tcpm_set_current_limit(port, - tcpm_get_current_limit(port), - 5000); + u32 current_lim = tcpm_get_current_limit(port); + + if (port->slow_charger_loop || (current_lim > PD_P_SNK_STDBY_MW / 5)) + current_lim = PD_P_SNK_STDBY_MW / 5; + tcpm_set_current_limit(port, current_lim, 5000); tcpm_set_charge(port, true); tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0); break; @@ -4161,6 +4169,8 @@ static void run_state_machine(struct tcpm_port *port) port->pwr_opmode = TYPEC_PWR_MODE_PD; } + if (!port->pd_capable && port->slow_charger_loop) + tcpm_set_current_limit(port, tcpm_get_current_limit(port), 5000); tcpm_swap_complete(port, 0); tcpm_typec_connect(port); mod_enable_frs_delayed_work(port, 0); @@ -5763,6 +5773,7 @@ static int tcpm_fw_get_caps(struct tcpm_port *port, port->typec_caps.type = ret; port->port_type = port->typec_caps.type; + port->slow_charger_loop = fwnode_property_read_bool(fwnode, "slow-charger-loop"); if (port->port_type == TYPEC_PORT_SNK) goto sink; -- 2.31.1.295.g9ea45b61b8-goog