From mboxrd@z Thu Jan 1 00:00:00 1970 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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 458C3C4338F for ; Fri, 6 Aug 2021 18:43:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2232560EC0 for ; Fri, 6 Aug 2021 18:43:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243289AbhHFSn4 convert rfc822-to-8bit (ORCPT ); Fri, 6 Aug 2021 14:43:56 -0400 Received: from relay8-d.mail.gandi.net ([217.70.183.201]:42887 "EHLO relay8-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231889AbhHFSny (ORCPT ); Fri, 6 Aug 2021 14:43:54 -0400 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay8-d.mail.gandi.net (Postfix) with ESMTPSA id 8AC7A1BF205; Fri, 6 Aug 2021 18:43:35 +0000 (UTC) Date: Fri, 6 Aug 2021 20:43:34 +0200 From: Miquel Raynal To: Apurva Nandan Cc: Richard Weinberger , Vignesh Raghavendra , Mark Brown , Patrice Chotard , Boris Brezillon , , , , Pratyush Yadav Subject: Re: [PATCH 04/13] mtd: spinand: Fix odd byte addr and data phase in read/write reg op and write VCR op for Octal DTR mode Message-ID: <20210806204334.5fedea42@xps13> In-Reply-To: <20210713130538.646-5-a-nandan@ti.com> References: <20210713130538.646-1-a-nandan@ti.com> <20210713130538.646-5-a-nandan@ti.com> Organization: Bootlin X-Mailer: Claws Mail 3.17.7 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org Hi Apurva, Apurva Nandan wrote on Tue, 13 Jul 2021 13:05:29 +0000: > In Octal DTR SPI mode, 2 bytes of data gets transmitted over one clock > cycle, and half-cycle instruction phases aren't supported yet. So, > every DTR spi_mem_op needs to have even nbytes in all phases for > non-erratic behaviour from the SPI controller. > > The odd length cmd and dummy phases get handled by spimem_setup_op() > but the odd length address and data phases need to be handled according > to the use case. For example in Octal DTR mode, read register operation > has one byte long address and data phase. So it needs to extend it > by adding a suitable extra byte in addr and reading 2 bytes of data, > discarding the second byte. > > Handle address and data phases for Octal DTR mode in read/write > register and write volatile configuration register operations > by adding a suitable extra byte in the address and data phase. > > Create spimem_setup_reg_op() helper function to ease setting up > read/write register operations in other functions, e.g. wait(). > > Signed-off-by: Apurva Nandan > --- > drivers/mtd/nand/spi/core.c | 26 +++++++++++++++++++++----- > 1 file changed, 21 insertions(+), 5 deletions(-) > > diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c > index 2e59faecc8f5..a5334ad34f96 100644 > --- a/drivers/mtd/nand/spi/core.c > +++ b/drivers/mtd/nand/spi/core.c > @@ -65,12 +65,27 @@ static void spinand_setup_op(const struct spinand_device *spinand, > } > } > > +static void spinand_setup_reg_op(const struct spinand_device *spinand, > + struct spi_mem_op *op) Same remark about the naming. In fact I believe we could have this logic in _setup_op() (or whatever its name) and add a specific parameter for it? > +{ > + if (spinand->reg_proto == SPINAND_OCTAL_DTR) { > + /* > + * Assigning same first and second byte will result in constant > + * bits on ths SPI bus between positive and negative clock edges the > + */ > + op->addr.val = (op->addr.val << 8) | op->addr.val; I am not sure to understand what you do here? > + op->addr.nbytes = 2; > + op->data.nbytes = 2; > + } Space > + spinand_setup_op(spinand, op); > +} > + > static int spinand_read_reg_op(struct spinand_device *spinand, u8 reg, u8 *val) > { > - struct spi_mem_op op = SPINAND_GET_FEATURE_OP(reg, > - spinand->scratchbuf); > + struct spi_mem_op op = SPINAND_GET_FEATURE_OP(reg, spinand->scratchbuf); You can do this, but in a different commit. > int ret; > > + spinand_setup_reg_op(spinand, &op); > ret = spi_mem_exec_op(spinand->spimem, &op); > if (ret) > return ret; > @@ -81,10 +96,10 @@ static int spinand_read_reg_op(struct spinand_device *spinand, u8 reg, u8 *val) > > static int spinand_write_reg_op(struct spinand_device *spinand, u8 reg, u8 val) > { > - struct spi_mem_op op = SPINAND_SET_FEATURE_OP(reg, > - spinand->scratchbuf); > + struct spi_mem_op op = SPINAND_SET_FEATURE_OP(reg, spinand->scratchbuf); Same here. > > - *spinand->scratchbuf = val; > + spinand_setup_reg_op(spinand, &op); > + memset(spinand->scratchbuf, val, op.data.nbytes); > return spi_mem_exec_op(spinand->spimem, &op); > } > > @@ -547,6 +562,7 @@ static int spinand_wait(struct spinand_device *spinand, > u8 status; > int ret; > > + spinand_setup_reg_op(spinand, &op); > ret = spi_mem_poll_status(spinand->spimem, &op, STATUS_BUSY, 0, > initial_delay_us, > poll_delay_us, Thanks, Miquèl