From patchwork Tue Apr 10 22:44:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris Brezillon X-Patchwork-Id: 10334329 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 511556053B for ; Tue, 10 Apr 2018 22:44:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3CE8728536 for ; Tue, 10 Apr 2018 22:44:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 317112853A; Tue, 10 Apr 2018 22:44:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C5A7F28538 for ; Tue, 10 Apr 2018 22:44:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752078AbeDJWot (ORCPT ); Tue, 10 Apr 2018 18:44:49 -0400 Received: from mail.bootlin.com ([62.4.15.54]:34630 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756123AbeDJWor (ORCPT ); Tue, 10 Apr 2018 18:44:47 -0400 Received: by mail.bootlin.com (Postfix, from userid 110) id 25AC320893; Wed, 11 Apr 2018 00:44:46 +0200 (CEST) Received: from localhost.localdomain (unknown [91.160.177.164]) by mail.bootlin.com (Postfix) with ESMTPSA id B7FCE20728; Wed, 11 Apr 2018 00:44:45 +0200 (CEST) From: Boris Brezillon To: David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Richard Weinberger , Cyrille Pitchen , linux-mtd@lists.infradead.org, Miquel Raynal , Mark Brown , linux-spi@vger.kernel.org Cc: Peter Pan , Frieder Schrempf , Vignesh R , Yogesh Gaur , =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= , Kamal Dasu , Sourav Poddar , Maxime Chevallier Subject: [PATCH v2 05/10] spi: Make support for regular transfers optional when ->mem_ops != NULL Date: Wed, 11 Apr 2018 00:44:34 +0200 Message-Id: <20180410224439.9260-6-boris.brezillon@bootlin.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180410224439.9260-1-boris.brezillon@bootlin.com> References: <20180410224439.9260-1-boris.brezillon@bootlin.com> Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Some SPI/QuadSPI controllers only expose a high-level SPI memory interface, thus preventing any regular SPI transfers from being done. In that case, SPI controller drivers can leave all ->transfer_xxx() hooks empty and only implement the spi_mem_ops interface. Adjust the core to allow such situations: - extend spi_controller_check_ops() to accept situations where all ->transfer_xxx() pointers are NULL only if ->mem_ops != NULL - make sure we do not initialize the SPI message queue if ctlr->transfer_one and ctlr->transfer_one_message are missing - return -ENOTSUPP if someone tries to do a regular SPI transfer on a controller that does not support it Signed-off-by: Boris Brezillon --- drivers/spi/spi.c | 33 ++++++++++++++++++++++++++------- 1 file changed, 26 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index d7e046128b3f..4961a5e91941 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -2069,12 +2070,19 @@ static int of_spi_register_master(struct spi_controller *ctlr) static int spi_controller_check_ops(struct spi_controller *ctlr) { /* - * The controller must at least implement one of the ->transfer() - * hooks. + * The controller may implement only the high-level SPI-memory like + * operations if it does not support regular SPI transfers, and this is + * valid use case. + * If ->mem_ops is NULL, we request that at least one of the + * ->transfer_xxx() method be implemented. */ - if (!ctlr->transfer && !ctlr->transfer_one && - !ctlr->transfer_one_message) + if (ctlr->mem_ops) { + if (!ctlr->mem_ops->exec_op) + return -EINVAL; + } else if (!ctlr->transfer && !ctlr->transfer_one && + !ctlr->transfer_one_message) { return -EINVAL; + } return 0; } @@ -2185,10 +2193,14 @@ int spi_register_controller(struct spi_controller *ctlr) spi_controller_is_slave(ctlr) ? "slave" : "master", dev_name(&ctlr->dev)); - /* If we're using a queued driver, start the queue */ - if (ctlr->transfer) + /* + * If we're using a queued driver, start the queue. Note that we don't + * need the queueing logic if the driver is only supporting high-level + * memory operations. + */ + if (ctlr->transfer) { dev_info(dev, "controller is unqueued, this is deprecated\n"); - else { + } else if (ctlr->transfer_one || ctlr->transfer_one_message) { status = spi_controller_initialize_queue(ctlr); if (status) { device_del(&ctlr->dev); @@ -2918,6 +2930,13 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) { struct spi_controller *ctlr = spi->controller; + /* + * Some controllers do not support doing regular SPI transfers. Return + * ENOTSUPP when this is the case. + */ + if (!ctlr->transfer) + return -ENOTSUPP; + message->spi = spi; SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);