From patchwork Wed May 20 16:30:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pratyush Yadav X-Patchwork-Id: 11560705 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6BE1713B1 for ; Wed, 20 May 2020 16:32:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 553B22075F for ; Wed, 20 May 2020 16:32:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="eOGNMxd7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727083AbgETQcR (ORCPT ); Wed, 20 May 2020 12:32:17 -0400 Received: from lelv0143.ext.ti.com ([198.47.23.248]:58712 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726436AbgETQcR (ORCPT ); Wed, 20 May 2020 12:32:17 -0400 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id 04KGVtv3044505; Wed, 20 May 2020 11:31:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1589992315; bh=c7C3r3QF/TMH/epmeuxUZDNfTYW7xsLdZE5YulWo4ZQ=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=eOGNMxd7eeQsbvjSQieSl0EIVwdPx2RA4gAimptThzpSa1jwuw3ElsK6q++64cgs4 gi1ttUr3cFKFYW8glk2r8Y0p6P6SoxGH1u7QFb2opDyvQ/foiwLk3ASOIK3ZycBPFR s3YelrnTDjrtldGrfTgJlT6MTtcwYjWasabFVZ40= Received: from DLEE113.ent.ti.com (dlee113.ent.ti.com [157.170.170.24]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTP id 04KGVseY109785; Wed, 20 May 2020 11:31:54 -0500 Received: from DLEE107.ent.ti.com (157.170.170.37) by DLEE113.ent.ti.com (157.170.170.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Wed, 20 May 2020 11:31:54 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE107.ent.ti.com (157.170.170.37) 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; Wed, 20 May 2020 11:31:54 -0500 Received: from pratyush-OptiPlex-790.dhcp.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 04KGUsxa001551; Wed, 20 May 2020 11:31:50 -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 v6 11/19] mtd: spi-nor: core: do 2 byte reads for SR and FSR in DTR mode Date: Wed, 20 May 2020 22:00:45 +0530 Message-ID: <20200520163053.24357-12-p.yadav@ti.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200520163053.24357-1-p.yadav@ti.com> References: <20200520163053.24357-1-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);