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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 E561FC433DF for ; Fri, 12 Jun 2020 07:58:56 +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 965CC207D8 for ; Fri, 12 Jun 2020 07:58:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="rm6sBW9l" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 965CC207D8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org 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:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=2UU1eniN4jEeWajjTOFZ82UHSDcndPeUvvLFYOTRc0A=; b=rm6sBW9lNemQf4 +IF9E9ugds9E0O8FrRIXV/LqLMwMam7BB6k0EMPyer+mIQhBrNaIogIbalc9Gxh5a3EpzEFZNbMY/ j/5eHn/E5DD98J1JAX/ABOyIG5V1XdygGNZMiWhhzPoFFTU7GVnKkHQi3cuv3eIW+Is1Pdqt7fxXr PyGfU8JLd0qRZ93yR/q1SX5sLeYyVslwhWrMmMQE6EZfIMxNNrvGGldm8ICiSgvllhewBV9E86+3m bEZdiaibCzwEV7WAwzUkFN43NkQUdFGRCJUdw30YMCx+H2q4LqmKdTkAx+uOfI9qqemC2R9BKhVp6 xVHX7mgomHUgHssQTYkg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jjeaF-0001CK-AV; Fri, 12 Jun 2020 07:58:39 +0000 Received: from alexa-out-sd-02.qualcomm.com ([199.106.114.39]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jjeaC-00019A-Os for linux-mtd@lists.infradead.org; Fri, 12 Jun 2020 07:58:38 +0000 Received: from unknown (HELO ironmsg-SD-alpha.qualcomm.com) ([10.53.140.30]) by alexa-out-sd-02.qualcomm.com with ESMTP; 12 Jun 2020 00:58:25 -0700 Received: from sivaprak-linux.qualcomm.com ([10.201.3.202]) by ironmsg-SD-alpha.qualcomm.com with ESMTP; 12 Jun 2020 00:58:23 -0700 Received: by sivaprak-linux.qualcomm.com (Postfix, from userid 459349) id CE32321880; Fri, 12 Jun 2020 13:28:21 +0530 (IST) From: Sivaprakash Murugesan To: miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com, peter.ujfalusi@ti.com, sivaprak@codeaurora.org, boris.brezillon@collabora.com, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH V4 2/2] mtd: rawnand: qcom: set BAM mode only if not set already Date: Fri, 12 Jun 2020 13:28:16 +0530 Message-Id: <1591948696-16015-3-git-send-email-sivaprak@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1591948696-16015-1-git-send-email-sivaprak@codeaurora.org> References: <1591948696-16015-1-git-send-email-sivaprak@codeaurora.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200612_005836_859750_6D6E4190 X-CRM114-Status: UNSURE ( 8.73 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 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 BAM is DMA controller on QCOM ipq platforms, BAM mode on NAND driver is set by writing BAM_MODE_EN bit on NAND_CTRL register. NAND_CTRL is an operational register and in BAM mode operational registers are read only. So, before enabling BAM mode by writing the NAND_CTRL register, check if BAM mode was already enabled by the bootloader, and enable BAM mode only if it is not enabled already. Signed-off-by: Sivaprakash Murugesan --- drivers/mtd/nand/raw/qcom_nandc.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c index 78b5f21..a3ef428 100644 --- a/drivers/mtd/nand/raw/qcom_nandc.c +++ b/drivers/mtd/nand/raw/qcom_nandc.c @@ -2784,7 +2784,14 @@ static int qcom_nandc_setup(struct qcom_nand_controller *nandc) /* enable ADM or BAM DMA */ if (nandc->props->is_bam) { nand_ctrl = nandc_read(nandc, NAND_CTRL); - nandc_write(nandc, NAND_CTRL, nand_ctrl | BAM_MODE_EN); + /* NAND_CTRL is an operational registers, and CPU + * access to operational registers are read only + * in BAM mode. So update the NAND_CTRL register + * only if it is not in BAM mode. In most cases BAM + * mode will be enabled in bootloader + */ + if (!(nand_ctrl | BAM_MODE_EN)) + nandc_write(nandc, NAND_CTRL, nand_ctrl | BAM_MODE_EN); } else { nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN); } -- 2.7.4 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/