From patchwork Thu Oct 12 20:52:19 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Norris X-Patchwork-Id: 825087 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.b="W92V2Bno"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3yCjkC1H09z9sBW for ; Fri, 13 Oct 2017 07:53:39 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755274AbdJLUxg (ORCPT ); Thu, 12 Oct 2017 16:53:36 -0400 Received: from mail-pf0-f181.google.com ([209.85.192.181]:47143 "EHLO mail-pf0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755214AbdJLUwe (ORCPT ); Thu, 12 Oct 2017 16:52:34 -0400 Received: by mail-pf0-f181.google.com with SMTP id z11so6603996pfk.4 for ; Thu, 12 Oct 2017 13:52:33 -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; bh=dnH5A9agN+AqHbnjhAY8RChCdBxo0Fr8J2aLGGv5zBU=; b=W92V2BnouHD7lgjA6ZVAfwMuhe9hyWL95tsd5GyJV3/wom2tXc+yZf03S46jbz7GeW MnG1iJhuHbMDh+CUl7OYVyoZcBhaUpkdfdXO5t57wN9LGDfS/UJBqzH+wkxQZWcVG5h2 IEONh+BBqXZNBXss8d6Sie2zuw+kxyDQim1P4= 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; bh=dnH5A9agN+AqHbnjhAY8RChCdBxo0Fr8J2aLGGv5zBU=; b=tWMoGH3jhAYB8ZtoxTCYi3LEzYa6v2miUyMLzylwFuKKHcM3aHjopfIB0+zlD8vkr+ sfyry1zqScWNWy1INJrLYCjzDxE9Qx67pAOfxOMLDeeW6Sbck4Rvp/2thwGhbk28VL6k j2WoCANli3IiUV0DpTiHOoqJXmU4QOQ3rgw4HTdLmuk1OfebjYpxhGrU9YyrsHQTlvfu xlRvnlxoMY9L7DHPLNAvlwqyDiT8NN8D/3p4/pMfbYWH/8dmgls8rOTSRsO/BYicfLnT 2LF12pWgPF6vqMiDBwYyeJTQdd9f3norxaBwbUVD777AOrqlYBXDfJ43CyjprV3FSdtb rCuA== X-Gm-Message-State: AMCzsaUS0S4JD5nhMT+Ki//2scImoEF1I8Y9YzkB7DMlcNIcsV0uP5GE deQJwVB6niowmLing5EcW8lgbA== X-Google-Smtp-Source: AOwi7QBlyTauwjzQ/g322s6jzdis7/MH92T885b/e1mC3PKBwYJgpircxpWYeiD2vRW/64gNiF3uog== X-Received: by 10.84.129.65 with SMTP id 59mr1181421plb.442.1507841553498; Thu, 12 Oct 2017 13:52:33 -0700 (PDT) Received: from ban.mtv.corp.google.com ([172.22.113.17]) by smtp.gmail.com with ESMTPSA id h1sm25048704pgp.37.2017.10.12.13.52.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 12 Oct 2017 13:52:33 -0700 (PDT) From: Brian Norris To: Bjorn Helgaas Cc: Rajat Jain , Rob Herring , Mark Rutland , Frank Rowand , Shawn Lin , Heiko Stuebner , linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Brian Norris Subject: [PATCH 2/3] of/pci: Add of_pci_get_pcie_reset_suspend() to parse pcie-reset-suspend Date: Thu, 12 Oct 2017 13:52:19 -0700 Message-Id: <20171012205220.130048-3-briannorris@chromium.org> X-Mailer: git-send-email 2.15.0.rc0.271.g36b669edcc-goog In-Reply-To: <20171012205220.130048-1-briannorris@chromium.org> References: <20171012205220.130048-1-briannorris@chromium.org> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org This helper can be used by drivers to determine the expected PERST# behavior when in low-power system suspend (e.g., S3). I've found the expected behavior to vary across a few different endpoint implementations. Signed-off-by: Brian Norris --- drivers/of/of_pci.c | 25 +++++++++++++++++++++++++ include/linux/of_pci.h | 7 +++++++ 2 files changed, 32 insertions(+) diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c index e9ec931f5b9a..ab2586f86094 100644 --- a/drivers/of/of_pci.c +++ b/drivers/of/of_pci.c @@ -137,6 +137,31 @@ int of_pci_get_max_link_speed(struct device_node *node) } EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed); +/** + * This function returns true if the PCIe controller should assert PCIe Reset + * (PERST#) when entering system suspend (e.g., S3). + * + * @node: device tree node with the reset property + * + * Returns 1 (meaning "assert reset") or 0 ("don't assert reset"), if the DT + * defined a valid behavior. Otherwise, returns a negative error code. + */ +int of_pci_get_pcie_reset_suspend(struct device_node *node) +{ + int ret; + u32 val; + + ret = of_property_read_u32(node, "pcie-reset-suspend", &val); + if (ret) + return ret; + + if (val > 1) + return -EINVAL; + + return val; +} +EXPORT_SYMBOL_GPL(of_pci_get_pcie_reset_suspend); + /** * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only * is present and valid diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h index 518c8d20647a..df453893080b 100644 --- a/include/linux/of_pci.h +++ b/include/linux/of_pci.h @@ -17,6 +17,7 @@ int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin); int of_pci_parse_bus_range(struct device_node *node, struct resource *res); int of_get_pci_domain_nr(struct device_node *node); int of_pci_get_max_link_speed(struct device_node *node); +int of_pci_get_pcie_reset_suspend(struct device_node *node); void of_pci_check_probe_only(void); int of_pci_map_rid(struct device_node *np, u32 rid, const char *map_name, const char *map_mask_name, @@ -69,6 +70,12 @@ of_pci_get_max_link_speed(struct device_node *node) return -EINVAL; } +static inline int +of_pci_get_pcie_reset_suspend(struct device_node *node) +{ + return -EINVAL; +} + static inline void of_pci_check_probe_only(void) { } #endif