From patchwork Tue Jul 12 15:06:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Stein X-Patchwork-Id: 590029 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB9CDC43334 for ; Tue, 12 Jul 2022 15:14:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229918AbiGLPOX (ORCPT ); Tue, 12 Jul 2022 11:14:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44004 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233235AbiGLPNu (ORCPT ); Tue, 12 Jul 2022 11:13:50 -0400 Received: from mx1.tq-group.com (mx1.tq-group.com [93.104.207.81]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BC63D1393; Tue, 12 Jul 2022 08:06:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tq-group.com; i=@tq-group.com; q=dns/txt; s=key1; t=1657638410; x=1689174410; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=OfgXpXXnxYkkdwb4bULIi/Pbx109DJwee81W/cf3QsM=; b=Maf5gXjPcn35A/9jvJKn2XzTDtwdW6Wlo+WOt8ObjYqYFhqpHWlKCJGe /wLhQpe54FVfcjpN+puM8xN21nQhzZkW6xqzkYw0dVyPryiUKQyWiniYC bldaEJ+vcQKVgoqB+Mw2j//894ScxVWeW3a02HeIhRc0S1Kt8+bkjBPvm /RVrCN1Kp28IixrDbxkLgXzVBJnc0+3v7CTJgeC1Wy+ted8waRKyZAf7T zS95DvSk84WZBRLvcfims6OKOexZIfDnJMUDJrJOosIb/CH/zjbPnIZHp 7/d9/YeEBEIUO+Tbglnew6v74SiXghR6lo1qbiU1m04pksZpdShRER+OO g==; X-IronPort-AV: E=Sophos;i="5.92,266,1650924000"; d="scan'208";a="25005746" Received: from unknown (HELO tq-pgp-pr1.tq-net.de) ([192.168.6.15]) by mx1-pgp.tq-group.com with ESMTP; 12 Jul 2022 17:06:47 +0200 Received: from mx1.tq-group.com ([192.168.6.7]) by tq-pgp-pr1.tq-net.de (PGP Universal service); Tue, 12 Jul 2022 17:06:47 +0200 X-PGP-Universal: processed; by tq-pgp-pr1.tq-net.de on Tue, 12 Jul 2022 17:06:47 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tq-group.com; i=@tq-group.com; q=dns/txt; s=key1; t=1657638407; x=1689174407; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=OfgXpXXnxYkkdwb4bULIi/Pbx109DJwee81W/cf3QsM=; b=pZxY0k/GxPT9fzQAfFCsullpK6SF5cWRHKvR6cqycTBkoXt2CxrUkfKP dt7QilL6/Zflulc0E0Ir23Bh/Rq2XnoyP01/jRxpzU6YFlWG1ILhq1Vrj 5ya14V7fuwA4a+TjRFmbnhDCDb3FHvnPCH2AX1X3FdFWOKKKS4ckZuJJY FLZhxosavLGGcxUlUQRkQ1ywo7lLYJ8cRbAREgCIeUXCOwQf3nglH379T DTLKkE6/jiv+XNA4Uk/Enwi48I5qVgMpH6PQU7gy81hPCmIwKKSCLLQfh 9d2VWiC5VaBZw70fJYHhBCOZhzuvN+RuSdSjRmkn/Dejs0ZPictoyNtwn g==; X-IronPort-AV: E=Sophos;i="5.92,266,1650924000"; d="scan'208";a="25005739" Received: from vtuxmail01.tq-net.de ([10.115.0.20]) by mx1.tq-group.com with ESMTP; 12 Jul 2022 17:06:32 +0200 Received: from steina-w.tq-net.de (unknown [10.123.49.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by vtuxmail01.tq-net.de (Postfix) with ESMTPSA id 02425280072; Tue, 12 Jul 2022 17:06:31 +0200 (CEST) From: Alexander Stein To: Greg Kroah-Hartman , Rob Herring , Krzysztof Kozlowski , Matthias Kaehlcke Cc: Alexander Stein , linux-usb@vger.kernel.org, devicetree@vger.kernel.org Subject: [PATCH 2/3] usb: misc: onboard_usb_hub: Add reset-gpio support Date: Tue, 12 Jul 2022 17:06:26 +0200 Message-Id: <20220712150627.1444761-2-alexander.stein@ew.tq-group.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220712150627.1444761-1-alexander.stein@ew.tq-group.com> References: <20220712150627.1444761-1-alexander.stein@ew.tq-group.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Despite default reset upon probe, release reset line after powering up the hub and assert reset again before powering down. Signed-off-by: Alexander Stein --- My current DT node on my TQMa8MPxL looks like this ``` &usb_dwc3_1 { dr_mode = "host"; #address-cells = <1>; #size-cells = <0>; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_usbhub>; status = "okay"; hub_2_0: hub@1 { compatible = "usb451,8142"; reg = <1>; peer-hub = <&hub_3_0>; reset-gpio = <&gpio1 11 GPIO_ACTIVE_LOW>; }; hub_3_0: hub@2 { compatible = "usb451,8140"; reg = <2>; peer-hub = <&hub_2_0>; reset-gpio = <&gpio1 11 GPIO_ACTIVE_LOW>; }; }; ``` which I don't like much for 2 reasons: * the pinctrl has to be put in a common top-node of USB hub node. The pinctrl can not be requested twice. * Apparently there is no conflict on the reset-gpio only because just one device gets probed here: > $ ls /sys/bus/platform/drivers/onboard-usb-hub/ > 38200000.usb:hub@1 bind uevent unbind But this seems better than to use a common fixed-regulator referenced by both hub nodes, which just is controlled by GPIO and does not supply any voltages. Note: It might also be necessary to add bindings to specify ramp up times and/or reset timeouts. drivers/usb/misc/onboard_usb_hub.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/usb/misc/onboard_usb_hub.c b/drivers/usb/misc/onboard_usb_hub.c index 6b9b949d17d3..348fb5270266 100644 --- a/drivers/usb/misc/onboard_usb_hub.c +++ b/drivers/usb/misc/onboard_usb_hub.c @@ -7,6 +7,7 @@ #include #include +#include #include #include #include @@ -38,6 +39,7 @@ struct usbdev_node { struct onboard_hub { struct regulator *vdd; struct device *dev; + struct gpio_desc *reset_gpio; bool always_powered_in_suspend; bool is_powered_on; bool going_away; @@ -56,6 +58,10 @@ static int onboard_hub_power_on(struct onboard_hub *hub) return err; } + /* Deassert reset */ + usleep_range(3000, 3100); + gpiod_set_value_cansleep(hub->reset_gpio, 0); + hub->is_powered_on = true; return 0; @@ -65,6 +71,10 @@ static int onboard_hub_power_off(struct onboard_hub *hub) { int err; + /* Assert reset */ + gpiod_set_value_cansleep(hub->reset_gpio, 1); + usleep_range(4000, 5000); + err = regulator_disable(hub->vdd); if (err) { dev_err(hub->dev, "failed to disable regulator: %d\n", err); @@ -231,6 +241,14 @@ static int onboard_hub_probe(struct platform_device *pdev) if (IS_ERR(hub->vdd)) return PTR_ERR(hub->vdd); + /* Put the hub into reset, pull reset line low, and assure 4ms reset low timing. */ + hub->reset_gpio = devm_gpiod_get_optional(dev, "reset", + GPIOD_OUT_HIGH); + if (IS_ERR(hub->reset_gpio)) + return dev_err_probe(dev, PTR_ERR(hub->reset_gpio), "failed to get reset GPIO\n"); + + usleep_range(4000, 5000); + hub->dev = dev; mutex_init(&hub->lock); INIT_LIST_HEAD(&hub->udev_list);