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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CB949C3DA6E for ; Fri, 5 Jan 2024 12:59:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Message-ID:References:In-Reply-To:Subject:Cc:To:From :Date:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=hdp3Ah2+vFmcgn2fOfoQymPB4JjeEHu9h49Y+p/a0PE=; b=lvw6yJF9dhZqZbsUnxovvDMTNd oOk2RgIEp/X6p5yUQ+epokQKQNilDdydQHhTfiFVYS92ScuyTaBSFRGhArCx0WaR6CHxRDaXOGBMp deS68/cT/FxQP7RbQUacfBtCjNOhgdbnZ5ykXyvbof2ayBXetH+6cG3mb22eMfS+r3qCB9FT/Cn3H k4eM9o1C5X8mfBjm3zr/4zQHpi4V2sle55jiqo4nQApdifkKdkrb2w6/L5Q6jAAa/ZMWgjgh/UAmC F41CNbbRoOl5t+4cJ9vy5l1d8PpuHM/gkLk8NPivmab5aQHz5OI3LC1Pi9FCi7hGAa0Sr/HgtXQLv XYiOwiWQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rLjn9-00Gt3P-10; Fri, 05 Jan 2024 12:59:15 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rLjn5-00Gt30-1X for linux-mtd@lists.infradead.org; Fri, 05 Jan 2024 12:59:13 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id D3306B81C9C; Fri, 5 Jan 2024 12:59:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8079AC433C8; Fri, 5 Jan 2024 12:59:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1704459549; bh=ka5FjBQD6h9MVnE7ywo1QjJyFD10E0RfnM+xr8ah7nE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=GU4k/XH31uTap6FK2sP+rDyK7Va2IfWd7KfkRMkxgobSZZIolvF6hwdwiBqiBNjW8 wUzgKPhRImkUQ1sHjKw/FTa+dVjUEFbvMW8MP9/SBOgKUg4yr8VxXiYEUeGmj/wqnd qfNPkqVH1NRF9VQAmBaUTg2R8EFkhx25yd4tRvdOZZl9zLmLAC4W0b2b9Hds9DLtpN k9vGa/TCAizWWO1uPLRbqJ8+mUknw94ZFkjrVEB8z8FlbpEIlN92NomOkMdZlwcgOu dzJIrPLCosIvNtXdXNg62b7wyxkf0Dc7hmncBLriLbJgOd0YTi4qTNHT6KtSKlV7RC wgv4AKJOL45AA== MIME-Version: 1.0 Date: Fri, 05 Jan 2024 13:59:05 +0100 From: Michael Walle To: Jaime Liao Cc: linux-mtd@lists.infradead.org, tudor.ambarus@linaro.org, pratyush@kernel.org, miquel.raynal@bootlin.com, leoyu@mxic.com.tw, jaimeliao@mxic.com.tw Subject: Re: [PATCH v7 3/7] mtd: spi-nor: core: Allow specifying the byte order in DTR mode In-Reply-To: <20231221090702.103027-4-jaimeliao.tw@gmail.com> References: <20231221090702.103027-1-jaimeliao.tw@gmail.com> <20231221090702.103027-4-jaimeliao.tw@gmail.com> Message-ID: <103152f83138bbbadeea2798a11e6e2c@kernel.org> X-Sender: mwalle@kernel.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240105_045911_817322_C6F2E3DE X-CRM114-Status: GOOD ( 21.74 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org Hi, > Macronix swaps bytes on a 16-bit boundary when configured in Octal DTR. > The byte order of 16-bit words is swapped when read or written in > 8D-8D-8D > mode compared to STR modes. Allow operations to specify the byte order > in > DTR mode, so that controllers can swap the bytes back at run-time to > address the flash's endianness requirements, if they are capable. If > the > controllers are not capable of swapping the bytes, the protocol is > downgrade via spi_nor_spimem_adjust_hwcaps(). When available, the > swapping > of the bytes is always done regardless if it's a data or register > access, > so that we comply with the JESD216 requirements: "Byte order of 16-bit > words is swapped when read in 8D-8D-8D mode compared to 1-1-1". > > Merge Tudor's patch and add modifications for suiting newer version > of Linux kernel. > > Signed-off-by: Tudor Ambarus > Signed-off-by: JaimeLiao > --- > drivers/mtd/spi-nor/core.c | 8 ++++++++ > drivers/mtd/spi-nor/core.h | 1 + > 2 files changed, 9 insertions(+) > > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > index 1c443fe568cf..f659dd037a25 100644 > --- a/drivers/mtd/spi-nor/core.c > +++ b/drivers/mtd/spi-nor/core.c > @@ -70,6 +70,13 @@ static u8 spi_nor_get_cmd_ext(const struct spi_nor > *nor, > } > } > > +static inline bool spi_nor_is_octal_dtr_swab16(const struct spi_nor > *nor, > + enum spi_nor_protocol proto) > +{ > + return (proto == SNOR_PROTO_8_8_8_DTR) && > + (nor->flags & SNOR_F_DTR_SWAB16); > +} > + > /** > * spi_nor_spimem_setup_op() - Set up common properties of a spi-mem > op. > * @nor: pointer to a 'struct spi_nor' > @@ -105,6 +112,7 @@ void spi_nor_spimem_setup_op(const struct spi_nor > *nor, > op->addr.dtr = true; > op->dummy.dtr = true; > op->data.dtr = true; > + op->data.dtr_swab16 = spi_nor_is_octal_dtr_swab16(nor, proto); Just use dtr_swap16 = nor->flags & SNOR_F_DTR_SWAP16; Again, I don't really like DTR_SWAP16. JESD216 just mention swapping for 8d8d8d. Depends on how generic we want to go. I'd go with swap16 and mention that for now, it is only applicable if data.buswidth == 8 and data.dtr == true. -michael > /* 2 bytes per clock cycle in DTR mode. */ > op->dummy.nbytes *= 2; > diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h > index 93cd2fc3606d..fe1259b32110 100644 > --- a/drivers/mtd/spi-nor/core.h > +++ b/drivers/mtd/spi-nor/core.h > @@ -140,6 +140,7 @@ enum spi_nor_option_flags { > SNOR_F_RWW = BIT(14), > SNOR_F_ECC = BIT(15), > SNOR_F_NO_WP = BIT(16), > + SNOR_F_DTR_SWAB16 = BIT(17), > }; > > struct spi_nor_read_command { ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/