From patchwork Wed Apr 14 14:26:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Badhri Jagan Sridharan X-Patchwork-Id: 12202995 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=ham 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 6E714C433B4 for ; Wed, 14 Apr 2021 14:27:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E22A61139 for ; Wed, 14 Apr 2021 14:27:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349525AbhDNO11 (ORCPT ); Wed, 14 Apr 2021 10:27:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344300AbhDNO1Y (ORCPT ); Wed, 14 Apr 2021 10:27:24 -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 30440C061574 for ; Wed, 14 Apr 2021 07:27:03 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id e9so1199331ybq.22 for ; Wed, 14 Apr 2021 07:27:03 -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=JZNxMt0kYcdl81T06jwbz7bLyJzhVKeZXhsmaV0aays=; b=ZE7ec79JRJhAh8rz0SBhyvoILEfHFixFNghu6rEe2f1YexSR3aZx4u+OAuxRxQfX3W /Dtmoy4YPFGN+3lcE9oqKdLqdiRpM74GPwct/F7KBAIU2CwOCU2yk7Kgf59LNemHq+1Y uSP1VagOZTjumSCMsAhS15UE16C6RetQ0qKVUJbpghHeTvheg/ppOohtfLqDhqgBdYeZ IwEUiYg9324fRGmLYSKgprJY/aTsC0Xe+0KCg8//udlWAxRBJn4hMC0W8N7Kbtmo3oRk e2rGI+NfAXOM0aoT7GwkbQyfqau27dQEsl6Bavpz754cnIi326VDG4jGJ7VZLJ1HnVwB ADow== 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=JZNxMt0kYcdl81T06jwbz7bLyJzhVKeZXhsmaV0aays=; b=jAlpoqGbgr4LtEYi1v8bT6liESsJhSWpegPF/enbHEJqGR4Lz2hDkLIZE3cwIvSl8h m5C4nBQh1JZkqieiLT4gUubmfds9pT5HYa2oNM8ADCnwry+AGDL/ENuTMhx1aH+4vGc6 JlOliT8LX7H164usuiqVw/jmdbDhDFK3uuudoFvsfDSAh/Z9OfkHVasKyhsLGLd6Gtp2 zRaYVP8T0FMATUd/XMOCm7WFa14QghWS3qZUni74KLizvI7tQX7r0hPSQA8h7P/uKmo5 Kxy+A2iVDmaSyS4g7eTGQ0mDq/CfaA75dQpWLB/VTskjNPXF/2/oJdDFClwd2i+t7lKZ 0jAQ== X-Gm-Message-State: AOAM530aVpEo99pjYiOMpLOZRbcwFir4kK91rRxPz0S7r/QzS8FehSoh CBw0HQpCvUxgp9nogHuMv670PzQxzgA= X-Google-Smtp-Source: ABdhPJxBXTM7Q7HPBfGGbJx2oJtJgz+0hipcgbym5Sq9aj2qEf2V897DLXh+m+8SP5J3+G90lrqV+m3pUXE= X-Received: from badhri.mtv.corp.google.com ([2620:15c:211:201:91dd:58ac:7590:aa21]) (user=badhri job=sendgmr) by 2002:a25:cc84:: with SMTP id l126mr31805689ybf.487.1618410422394; Wed, 14 Apr 2021 07:27:02 -0700 (PDT) Date: Wed, 14 Apr 2021 07:26:55 -0700 In-Reply-To: <20210414142656.63749-1-badhri@google.com> Message-Id: <20210414142656.63749-2-badhri@google.com> Mime-Version: 1.0 References: <20210414142656.63749-1-badhri@google.com> X-Mailer: git-send-email 2.31.1.295.g9ea45b61b8-goog Subject: [PATCH v4 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 Precedence: bulk List-ID: X-Mailing-List: linux-usb@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 Reviewed-by: Heikki Krogerus --- Changes since V3: * Added reviewed-by tag from Heikki 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;