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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 7D46AC43219 for ; Tue, 30 Apr 2019 10:04:36 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 4ECA52075E for ; Tue, 30 Apr 2019 10:04:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="fc9lulJO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4ECA52075E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=sslMPdzGGqNF2CDiovvDnyKpRMzLdyXn/bTP40C215g=; b=fc9lulJOff/TQ7 alQVvisqSBuKZXIX/IqbDMr5Um9l8CX9X2PIul4iJWKC8CMA0TvAjbu6iQMOIGa+uxKYtg4BSPlNN rAYTsaL0xu+SzzxYpmWDpCg4tC7iSzniJXP3meOXkCfhxizwH1fykPjewFy1wgTtxkIs6Q0f8L4kk l5YOxxDB0MTqh3vTZGv5LHclyC8yWOh7bw6UUVWrnYryki1S3pa4K138hV3swu6PjqKV8BkebMoOv DUR9CgmXF8IPdspIk417nHNpZXpKMu53S7fVXpU65Ot1CQkGvOSOumjdthpOywMtqkM5LnUq6hKpf QmdKH920CsdepOul9Akw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hLPcm-0000xi-Hg; Tue, 30 Apr 2019 10:04:32 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hLPcQ-0000UT-7k; Tue, 30 Apr 2019 10:04:12 +0000 X-UUID: fd97d828dd56461fbde749a8d81d498a-20190430 X-UUID: fd97d828dd56461fbde749a8d81d498a-20190430 Received: from mtkcas68.mediatek.inc [(172.29.94.19)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLS) with ESMTP id 1100900683; Tue, 30 Apr 2019 02:04:03 -0800 Received: from mtkmbs03n1.mediatek.inc (172.21.101.181) by MTKMBS62N2.mediatek.inc (172.29.193.42) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 30 Apr 2019 03:04:02 -0700 Received: from MTKCAS06.mediatek.inc (172.21.101.30) by mtkmbs03n1.mediatek.inc (172.21.101.181) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 30 Apr 2019 18:04:00 +0800 Received: from mtkslt306.mediatek.inc (10.21.14.136) by MTKCAS06.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Tue, 30 Apr 2019 18:04:00 +0800 From: Xiaolei Li To: , Subject: [PATCH v2 1/5] mtd: rawnand: mtk: Correct low level time calculation of r/w cycle Date: Tue, 30 Apr 2019 18:02:46 +0800 Message-ID: <20190430100250.28083-2-xiaolei.li@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20190430100250.28083-1-xiaolei.li@mediatek.com> References: <20190430100250.28083-1-xiaolei.li@mediatek.com> MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190430_030410_285018_0DBC6EA8 X-CRM114-Status: GOOD ( 13.10 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-mediatek@lists.infradead.org, xiaolei.li@mediatek.com, linux-mtd@lists.infradead.org, stable@vger.kernel.org, srv_heupstream@mediatek.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org At present, the flow of calculating AC timing of read/write cycle in SDR mode is that: At first, calculate high hold time which is valid for both read and write cycle using the max value between tREH_min and tWH_min. Secondly, calculate WE# pulse width using tWP_min. Thridly, calculate RE# pulse width using the bigger one between tREA_max and tRP_min. But NAND SPEC shows that Controller should also meet write/read cycle time. That is write cycle time should be more than tWC_min and read cycle should be more than tRC_min. Obviously, we do not achieve that now. This patch corrects the low level time calculation to meet minimum read/write cycle time required. After getting the high hold time, WE# low level time will be promised to meet tWP_min and tWC_min requirement, and RE# low level time will be promised to meet tREA_max, tRP_min and tRC_min requirement. Fixes: edfee3619c49 ("mtd: nand: mtk: add ->setup_data_interface() hook") Cc: stable@vger.kernel.org Signed-off-by: Xiaolei Li --- drivers/mtd/nand/raw/mtk_nand.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/mtd/nand/raw/mtk_nand.c b/drivers/mtd/nand/raw/mtk_nand.c index b6b4602f5132..4fbb0c6ecae3 100644 --- a/drivers/mtd/nand/raw/mtk_nand.c +++ b/drivers/mtd/nand/raw/mtk_nand.c @@ -508,7 +508,8 @@ static int mtk_nfc_setup_data_interface(struct nand_chip *chip, int csline, { struct mtk_nfc *nfc = nand_get_controller_data(chip); const struct nand_sdr_timings *timings; - u32 rate, tpoecs, tprecs, tc2r, tw2r, twh, twst, trlt; + u32 rate, tpoecs, tprecs, tc2r, tw2r, twh, twst = 0, trlt = 0; + u32 thold; timings = nand_get_sdr_timings(conf); if (IS_ERR(timings)) @@ -544,11 +545,28 @@ static int mtk_nfc_setup_data_interface(struct nand_chip *chip, int csline, twh = DIV_ROUND_UP(twh * rate, 1000000) - 1; twh &= 0xf; - twst = timings->tWP_min / 1000; + /* Calculate real WE#/RE# hold time in nanosecond */ + thold = (twh + 1) * 1000000 / rate; + /* nanosecond to picosecond */ + thold *= 1000; + + /** + * WE# low level time should be expaned to meet WE# pulse time + * and WE# cycle time at the same time. + */ + if (thold < timings->tWC_min) + twst = timings->tWC_min - thold; + twst = max(timings->tWP_min, twst) / 1000; twst = DIV_ROUND_UP(twst * rate, 1000000) - 1; twst &= 0xf; - trlt = max(timings->tREA_max, timings->tRP_min) / 1000; + /** + * RE# low level time should be expaned to meet RE# pulse time, + * RE# access time and RE# cycle time at the same time. + */ + if (thold < timings->tRC_min) + trlt = timings->tRC_min - thold; + trlt = max3(trlt, timings->tREA_max, timings->tRP_min) / 1000; trlt = DIV_ROUND_UP(trlt * rate, 1000000) - 1; trlt &= 0xf; -- 2.18.0 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/