From patchwork Tue May 19 14:26:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pratyush Yadav X-Patchwork-Id: 214624 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59DEDC433E0 for ; Tue, 19 May 2020 14:28:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3418D20825 for ; Tue, 19 May 2020 14:28:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="YBXGZ25N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728633AbgESO17 (ORCPT ); Tue, 19 May 2020 10:27:59 -0400 Received: from lelv0143.ext.ti.com ([198.47.23.248]:36870 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729196AbgESO15 (ORCPT ); Tue, 19 May 2020 10:27:57 -0400 Received: from lelv0265.itg.ti.com ([10.180.67.224]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id 04JERhke062708; Tue, 19 May 2020 09:27:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1589898463; bh=c7C3r3QF/TMH/epmeuxUZDNfTYW7xsLdZE5YulWo4ZQ=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=YBXGZ25NJhwEXR4yQ+KnYmqKXaaDebAeM+t7deatTCuJqzcJ96iqPNfSFoEf3ybuH SpPAC5wWiKhtcxxd2G1WZ0bx3y0Zm6yqOiyxRL2WIBa16FovPN0MSDeoi3JkQ2sNNh hCbIsOqJH8eHpTVBvxEU8uSWm+cEXu50Fq6BnyqI= Received: from DFLE114.ent.ti.com (dfle114.ent.ti.com [10.64.6.35]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 04JERhwZ082065 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 19 May 2020 09:27:43 -0500 Received: from DFLE108.ent.ti.com (10.64.6.29) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Tue, 19 May 2020 09:27:43 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DFLE108.ent.ti.com (10.64.6.29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3 via Frontend Transport; Tue, 19 May 2020 09:27:43 -0500 Received: from pratyush-OptiPlex-790.dhcp.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id 04JEQgjT008313; Tue, 19 May 2020 09:27:38 -0500 From: Pratyush Yadav To: Tudor Ambarus , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Mark Brown , Nicolas Ferre , Alexandre Belloni , Ludovic Desroches , Matthias Brugger , , , , , CC: Pratyush Yadav , Sekhar Nori , Boris Brezillon , Mason Yang Subject: [PATCH v5 11/19] mtd: spi-nor: core: do 2 byte reads for SR and FSR in DTR mode Date: Tue, 19 May 2020 19:56:33 +0530 Message-ID: <20200519142642.24131-12-p.yadav@ti.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200519142642.24131-1-p.yadav@ti.com> References: <20200519142642.24131-1-p.yadav@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org Some controllers, like the cadence qspi controller, have trouble reading only 1 byte in DTR mode. So, do 2 byte reads for SR and FSR commands in DTR mode, and then discard the second byte. Signed-off-by: Pratyush Yadav --- drivers/mtd/spi-nor/core.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 2ad248140b6c..5cb7e391cd29 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -350,7 +350,7 @@ int spi_nor_write_disable(struct spi_nor *nor) * spi_nor_read_sr() - Read the Status Register. * @nor: pointer to 'struct spi_nor'. * @sr: pointer to a DMA-able buffer where the value of the - * Status Register will be written. + * Status Register will be written. Should be at least 2 bytes. * * Return: 0 on success, -errno otherwise. */ @@ -371,6 +371,11 @@ static int spi_nor_read_sr(struct spi_nor *nor, u8 *sr) op.addr.nbytes = addr_bytes; op.addr.val = 0; op.dummy.nbytes = dummy; + /* + * We don't want to read only one byte in DTR mode. So, + * read 2 and then discard the second byte. + */ + op.data.nbytes = 2; } spi_nor_spimem_setup_op(nor, &op, nor->reg_proto); @@ -394,7 +399,8 @@ static int spi_nor_read_sr(struct spi_nor *nor, u8 *sr) * spi_nor_read_fsr() - Read the Flag Status Register. * @nor: pointer to 'struct spi_nor' * @fsr: pointer to a DMA-able buffer where the value of the - * Flag Status Register will be written. + * Flag Status Register will be written. Should be at least 2 + * bytes. * * Return: 0 on success, -errno otherwise. */ @@ -415,6 +421,11 @@ static int spi_nor_read_fsr(struct spi_nor *nor, u8 *fsr) op.addr.nbytes = addr_bytes; op.addr.val = 0; op.dummy.nbytes = dummy; + /* + * We don't want to read only one byte in DTR mode. So, + * read 2 and then discard the second byte. + */ + op.data.nbytes = 2; } spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);