From patchwork Thu Dec 2 16:24:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Binding X-Patchwork-Id: 12653101 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 59277C43217 for ; Thu, 2 Dec 2021 16:25:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359427AbhLBQ2e (ORCPT ); Thu, 2 Dec 2021 11:28:34 -0500 Received: from mx0a-001ae601.pphosted.com ([67.231.149.25]:4180 "EHLO mx0b-001ae601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1347619AbhLBQ2c (ORCPT ); Thu, 2 Dec 2021 11:28:32 -0500 Received: from pps.filterd (m0077473.ppops.net [127.0.0.1]) by mx0a-001ae601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 1B24r9Mv013038; Thu, 2 Dec 2021 10:24:59 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cirrus.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=PODMain02222019; bh=76HTMV8KbuUL5hsVdys0VO+mEyDn+msgMSgJlOog7K4=; b=Y3REhZ04kM3AQEHk9wtmbsS/ZnDyq6jd0WT5j+KMDqj4ynlraKnZB/oicROtcZM0etL8 y6MrvLmmmmXYWw/n3E13z+I9mXC+Lc2MpnzBue76C2KnvEeoBCWwEcRcAE9AHRM28OOZ p8kYMUT+sslG56wGmNV/meKvJnjtrRMEOxpxDdqIGcO2vam3pmMWZrLvNxWVmWOrbqPl REvCTsRyhF2Tt48eg9Wdm1dMck1p/m9jjwh7h8qNpyNsJn4EpkUk9mjJ3khX9DqgPm+w GZ/PkDR9G5rLr/+rAM+tB0LCoMqolksXUSDJf+Z0ISpk0GSp8u2HALla/htaHp1HAvby ZA== Received: from ediex02.ad.cirrus.com ([84.19.233.68]) by mx0a-001ae601.pphosted.com (PPS) with ESMTPS id 3cp6c89wp4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Thu, 02 Dec 2021 10:24:59 -0600 Received: from EDIEX01.ad.cirrus.com (198.61.84.80) by EDIEX02.ad.cirrus.com (198.61.84.81) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.17; Thu, 2 Dec 2021 16:24:57 +0000 Received: from ediswmail.ad.cirrus.com (198.61.86.93) by EDIEX01.ad.cirrus.com (198.61.84.80) with Microsoft SMTP Server id 15.1.2375.17 via Frontend Transport; Thu, 2 Dec 2021 16:24:57 +0000 Received: from LONN2DGDQ73.ad.cirrus.com (unknown [198.90.238.136]) by ediswmail.ad.cirrus.com (Postfix) with ESMTP id 7F7212AA; Thu, 2 Dec 2021 16:24:56 +0000 (UTC) From: Stefan Binding To: Mark Brown , "Rafael J . Wysocki" , Len Brown , Hans de Goede , Mark Gross CC: , , , , , Lucas Tanure , Stefan Binding Subject: [PATCH 1/3] spi: Revert "spi: Remove unused function spi_busnum_to_master()" Date: Thu, 2 Dec 2021 16:24:19 +0000 Message-ID: <20211202162421.7628-1-sbinding@opensource.cirrus.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Proofpoint-ORIG-GUID: B7iDop18gN-_w8BoDZtY6kLxaA4i6EHT X-Proofpoint-GUID: B7iDop18gN-_w8BoDZtY6kLxaA4i6EHT X-Proofpoint-Spam-Reason: safe Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org From: Lucas Tanure Revert commit bdc7ca008e1f ("spi: Remove unused function spi_busnum_to_master()") This function is needed for the spi version of i2c multi instantiate driver. Signed-off-by: Lucas Tanure Signed-off-by: Stefan Binding --- Documentation/spi/spi-summary.rst | 8 +++++++ drivers/spi/spi.c | 35 +++++++++++++++++++++++++++++++ include/linux/spi/spi.h | 2 ++ 3 files changed, 45 insertions(+) diff --git a/Documentation/spi/spi-summary.rst b/Documentation/spi/spi-summary.rst index aab5d07cb3d7..d4239025461d 100644 --- a/Documentation/spi/spi-summary.rst +++ b/Documentation/spi/spi-summary.rst @@ -336,6 +336,14 @@ certainly includes SPI devices hooked up through the card connectors! Non-static Configurations ^^^^^^^^^^^^^^^^^^^^^^^^^ +Developer boards often play by different rules than product boards, and one +example is the potential need to hotplug SPI devices and/or controllers. + +For those cases you might need to use spi_busnum_to_master() to look +up the spi bus master, and will likely need spi_new_device() to provide the +board info based on the board that was hotplugged. Of course, you'd later +call at least spi_unregister_device() when that board is removed. + When Linux includes support for MMC/SD/SDIO/DataFlash cards through SPI, those configurations will also be dynamic. Fortunately, such devices all support basic device identification probes, so they should hotplug normally. diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 8726309b3eaf..7c81173edb0c 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -3145,6 +3145,41 @@ int spi_controller_resume(struct spi_controller *ctlr) } EXPORT_SYMBOL_GPL(spi_controller_resume); +static int __spi_controller_match(struct device *dev, const void *data) +{ + struct spi_controller *ctlr; + const u16 *bus_num = data; + + ctlr = container_of(dev, struct spi_controller, dev); + return ctlr->bus_num == *bus_num; +} + +/** + * spi_busnum_to_master - look up master associated with bus_num + * @bus_num: the master's bus number + * Context: can sleep + * + * This call may be used with devices that are registered after + * arch init time. It returns a refcounted pointer to the relevant + * spi_controller (which the caller must release), or NULL if there is + * no such master registered. + * + * Return: the SPI master structure on success, else NULL. + */ +struct spi_controller *spi_busnum_to_master(u16 bus_num) +{ + struct device *dev; + struct spi_controller *ctlr = NULL; + + dev = class_find_device(&spi_master_class, NULL, &bus_num, + __spi_controller_match); + if (dev) + ctlr = container_of(dev, struct spi_controller, dev); + /* reference got in class_find_device */ + return ctlr; +} +EXPORT_SYMBOL_GPL(spi_busnum_to_master); + /*-------------------------------------------------------------------------*/ /* Core methods for spi_message alterations */ diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index eb7ac8a1e03c..5f2781cb750f 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -759,6 +759,8 @@ extern int devm_spi_register_controller(struct device *dev, struct spi_controller *ctlr); extern void spi_unregister_controller(struct spi_controller *ctlr); +extern struct spi_controller *spi_busnum_to_master(u16 busnum); + /* * SPI resource management while processing a SPI message */