From patchwork Sat May 23 04:12:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prashant Malani X-Patchwork-Id: 11566559 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 0322C90 for ; Sat, 23 May 2020 04:12:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9D68207DA for ; Sat, 23 May 2020 04:12:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="aplJuZml" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387621AbgEWEMb (ORCPT ); Sat, 23 May 2020 00:12:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387615AbgEWEMb (ORCPT ); Sat, 23 May 2020 00:12:31 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A8A4C061A0E for ; Fri, 22 May 2020 21:12:31 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id u5so5928482pgn.5 for ; Fri, 22 May 2020 21:12:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=bLR6ZIRylvFFIxKdJ83iv09lWseVsvasJ0E1PrljIIA=; b=aplJuZmlLgHFVE2F12xlgenwp9VxB9NxBbFUKdNnmQzvgT2LDo7s5UCmQ+qrtoboaf zn5CIKnSME8rq5enWZ8nz5dIFTSqP3idH9HSp0N6WKayRMMfuf3TzYFSLkuqoib0kvgV Qhs9mcQej9SI9eTbqbiHkNxg0eRC3Kg7MVrA0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bLR6ZIRylvFFIxKdJ83iv09lWseVsvasJ0E1PrljIIA=; b=uXzFLKoSSDKD7iECsEaTJmvrjosxLX3Frp72XiX3GWmtZzuwEK4MsYM3cSrmKirb8B dsZynaRGtT39N8Bnm1YdoAky0BlULwOUzR+HmmonZCRhem0I6o7CIBtukIQMA5h8iuSf 7dxDShPuiYi5KhAYOQjeakOh1IeBB4FIJOJSQTKsySj/BOyEPEJiHRBbKzr5a9YsJ/pe TqJo3bQ1Vubh9xScd8hvHTXN7JdEHQv48g4BcKx06qcSSUGyKYQ9T15yUNv8yiqgJxSL uxJ2U6ToirXIaVVvxeZCrinqVB9vKKCXsBHglArx9Q5+76U32A7CPO5GMwVdw/rsvSlO 1Lzw== X-Gm-Message-State: AOAM5338+5Lh/B0jExUwGjtkmx/QnNERfAR1qiZBPyScsP86VvPId8ke xQicIGS5vNqf69i3TXXMlmn9+A== X-Google-Smtp-Source: ABdhPJyWhs3gIjSkezupuRAPz5rdIyxCk9/Qc1FlGjEqN7gxG/Bcg8Fg9+IvMTjHmsTFL3oMxffkPg== X-Received: by 2002:a62:cd8d:: with SMTP id o135mr6937224pfg.26.1590207150526; Fri, 22 May 2020 21:12:30 -0700 (PDT) Received: from pmalani2.mtv.corp.google.com ([2620:15c:202:201:476b:691:abc3:38db]) by smtp.gmail.com with ESMTPSA id h7sm7075741pgn.60.2020.05.22.21.12.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 May 2020 21:12:30 -0700 (PDT) From: Prashant Malani To: linux-kernel@vger.kernel.org Cc: enric.balletbo@collabora.com, bleung@chromium.org, groeck@chromium.org, Prashant Malani , Felipe Balbi , Greg Kroah-Hartman , linux-usb@vger.kernel.org (open list:DESIGNWARE USB3 DRD IP DRIVER) Subject: [RFC PATCH 1/1] usb: dwc3: of-simple: Add extcon support Date: Fri, 22 May 2020 21:12:02 -0700 Message-Id: <20200523041201.75217-2-pmalani@chromium.org> X-Mailer: git-send-email 2.27.0.rc0.183.gde8f92d652-goog In-Reply-To: <20200523041201.75217-1-pmalani@chromium.org> References: <20200523041201.75217-1-pmalani@chromium.org> MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Add optional extcon notifier support to enable the hotplug / unplug of the underlying PHY layer devices. If supported, the Device Tree (DT) node for the device should include an "extcon" property which is a phandle to an extcon DT node. This patch is an effort to incorporate the equivalent support from the Rockchip dwc3 driver implementation from Chrome OS [1] to the mainline. [1] : https://chromium.googlesource.com/chromiumos/third_party/kernel/ +/refs/heads/chromeos-4.4/drivers/usb/dwc3/dwc3-rockchip.c Cc: Benson Leung Cc: Guenter Roeck Cc: Enric Balletbo i Serra Signed-off-by: Prashant Malani Reviewed-by: Guenter Roeck --- drivers/usb/dwc3/dwc3-of-simple.c | 149 +++++++++++++++++++++++++++++- 1 file changed, 146 insertions(+), 3 deletions(-) diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c index e64754be47b4..28bde27cd1f9 100644 --- a/drivers/usb/dwc3/dwc3-of-simple.c +++ b/drivers/usb/dwc3/dwc3-of-simple.c @@ -11,6 +11,7 @@ * by Subbaraya Sundeep Bhatta */ +#include #include #include #include @@ -29,8 +30,117 @@ struct dwc3_of_simple { struct reset_control *resets; bool pulse_resets; bool need_reset; + struct extcon_dev *edev; + struct notifier_block nb; + struct work_struct work; + /* Denotes whether child devices have been populated. */ + bool populated; + bool suspended; + spinlock_t suspend_lock; }; +static int dwc3_of_simple_populate(struct dwc3_of_simple *simple) +{ + struct device *dev = simple->dev; + struct device_node *np = dev->of_node; + int ret; + + ret = of_platform_populate(np, NULL, NULL, dev); + if (ret) { + dev_err(dev, "Failed to populate dwc3 devices.\n"); + return ret; + } + simple->populated = true; + return 0; +} + +static void dwc3_of_simple_depopulate(struct dwc3_of_simple *simple) +{ + if (simple->populated) { + of_platform_depopulate(simple->dev); + simple->populated = false; + } +} + +static void dwc3_of_simple_work(struct work_struct *work) +{ + struct dwc3_of_simple *simple = container_of(work, + struct dwc3_of_simple, work); + struct extcon_dev *edev = simple->edev; + + if (extcon_get_state(edev, EXTCON_USB_HOST) > 0) { + if (simple->populated) + return; + + dwc3_of_simple_populate(simple); + } else { + if (!simple->populated) + return; + + dwc3_of_simple_depopulate(simple); + } +} + +static int dwc3_of_simple_notifier(struct notifier_block *nb, + unsigned long event, void *ptr) +{ + struct dwc3_of_simple *simple = container_of(nb, struct dwc3_of_simple, + nb); + unsigned long flags; + + spin_lock_irqsave(&simple->suspend_lock, flags); + if (!simple->suspended) + schedule_work(&simple->work); + spin_unlock_irqrestore(&simple->suspend_lock, flags); + + return NOTIFY_OK; +} + +static int dwc3_of_simple_extcon_register(struct dwc3_of_simple *simple) +{ + struct device *dev = simple->dev; + struct extcon_dev *edev; + int ret; + + edev = extcon_get_edev_by_phandle(dev, 0); + if (IS_ERR(edev)) { + /* The extcon property is optional. */ + if (PTR_ERR(edev) == -ENODEV) + return 0; + if (PTR_ERR(edev) != -EPROBE_DEFER) + dev_err(dev, "Couldn't get extcon device.\n"); + return PTR_ERR(edev); + } + + INIT_WORK(&simple->work, dwc3_of_simple_work); + + simple->nb.notifier_call = dwc3_of_simple_notifier; + ret = devm_extcon_register_notifier(dev, edev, EXTCON_USB_HOST, + &simple->nb); + if (ret < 0) { + dev_err(dev, "Failed to register notifier.\n"); + return ret; + } + + simple->edev = edev; + + return 0; +} + +static void dwc3_of_simple_extcon_unregister(struct dwc3_of_simple *simple) +{ + if (!simple->edev) + return; + + /* + * We explicitly unregister the notifier to prevent races with + * the of_depopulate() call in remove(). + */ + devm_extcon_unregister_notifier(simple->dev, simple->edev, + EXTCON_USB_HOST, &simple->nb); + cancel_work_sync(&simple->work); +} + static int dwc3_of_simple_probe(struct platform_device *pdev) { struct dwc3_of_simple *simple; @@ -47,6 +157,8 @@ static int dwc3_of_simple_probe(struct platform_device *pdev) platform_set_drvdata(pdev, simple); simple->dev = dev; + spin_lock_init(&simple->suspend_lock); + /* * Some controllers need to toggle the usb3-otg reset before trying to * initialize the PHY, otherwise the PHY times out. @@ -87,9 +199,24 @@ static int dwc3_of_simple_probe(struct platform_device *pdev) if (ret) goto err_resetc_assert; - ret = of_platform_populate(np, NULL, NULL, dev); - if (ret) + ret = dwc3_of_simple_extcon_register(simple); + if (ret < 0) { + dev_warn(dev, "No extcon device found, err: %d\n", ret); goto err_clk_put; + } + + if (!simple->edev) { + ret = dwc3_of_simple_populate(simple); + if (ret) + goto err_clk_put; + } else { + /* + * Populate through worker to avoid race conditions against + * action scheduled through notifier. + */ + if (extcon_get_state(simple->edev, EXTCON_USB_HOST) > 0) + schedule_work(&simple->work); + } pm_runtime_set_active(dev); pm_runtime_enable(dev); @@ -112,7 +239,8 @@ static int dwc3_of_simple_probe(struct platform_device *pdev) static void __dwc3_of_simple_teardown(struct dwc3_of_simple *simple) { - of_platform_depopulate(simple->dev); + dwc3_of_simple_extcon_unregister(simple); + dwc3_of_simple_depopulate(simple); clk_bulk_disable_unprepare(simple->num_clocks, simple->clks); clk_bulk_put_all(simple->num_clocks, simple->clks); @@ -163,6 +291,13 @@ static int __maybe_unused dwc3_of_simple_runtime_resume(struct device *dev) static int __maybe_unused dwc3_of_simple_suspend(struct device *dev) { struct dwc3_of_simple *simple = dev_get_drvdata(dev); + unsigned long flags; + + spin_lock_irqsave(&simple->suspend_lock, flags); + simple->suspended = true; + spin_unlock_irqrestore(&simple->suspend_lock, flags); + + cancel_work_sync(&simple->work); if (simple->need_reset) reset_control_assert(simple->resets); @@ -173,10 +308,18 @@ static int __maybe_unused dwc3_of_simple_suspend(struct device *dev) static int __maybe_unused dwc3_of_simple_resume(struct device *dev) { struct dwc3_of_simple *simple = dev_get_drvdata(dev); + unsigned long flags; if (simple->need_reset) reset_control_deassert(simple->resets); + spin_lock_irqsave(&simple->suspend_lock, flags); + simple->suspended = false; + spin_unlock_irqrestore(&simple->suspend_lock, flags); + + if (simple->edev) + schedule_work(&simple->work); + return 0; }