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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 13AC7C0044B for ; Mon, 1 Oct 2018 14:34:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D75C8208AE for ; Mon, 1 Oct 2018 14:34:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D75C8208AE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=opensource.cirrus.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729559AbeJAVMH (ORCPT ); Mon, 1 Oct 2018 17:12:07 -0400 Received: from mx0a-001ae601.pphosted.com ([67.231.149.25]:59654 "EHLO mx0b-001ae601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729439AbeJAVMG (ORCPT ); Mon, 1 Oct 2018 17:12:06 -0400 Received: from pps.filterd (m0077473.ppops.net [127.0.0.1]) by mx0a-001ae601.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w91EXwJb027369; Mon, 1 Oct 2018 09:33:58 -0500 Authentication-Results: ppops.net; spf=none smtp.mailfrom=rf@opensource.cirrus.com Received: from mail4.cirrus.com ([87.246.98.35]) by mx0a-001ae601.pphosted.com with ESMTP id 2mugjdgbcj-1; Mon, 01 Oct 2018 09:33:58 -0500 Received: from EX17.ad.cirrus.com (unknown [172.20.9.81]) by mail4.cirrus.com (Postfix) with ESMTP id A610D611C8BB; Mon, 1 Oct 2018 09:36:31 -0500 (CDT) Received: from imbe.wolfsonmicro.main (198.61.95.81) by EX17.ad.cirrus.com (172.20.9.81) with Microsoft SMTP Server id 14.3.408.0; Mon, 1 Oct 2018 15:33:57 +0100 Received: from edi-sw-dsktp006.ad.cirrus.com (edi-sw-dsktp006.ad.cirrus.com [198.90.251.121]) by imbe.wolfsonmicro.main (8.14.4/8.14.4) with ESMTP id w91EXvlp027435; Mon, 1 Oct 2018 15:33:57 +0100 From: Richard Fitzgerald To: CC: , , "Richard Fitzgerald" Subject: [PATCH 2/2] mfd: madera: Wait for BOOT_DONE before reading device ID Date: Mon, 1 Oct 2018 15:33:57 +0100 Message-ID: <20181001143357.28428-2-rf@opensource.cirrus.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20181001143357.28428-1-rf@opensource.cirrus.com> References: <20181001143357.28428-1-rf@opensource.cirrus.com> MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810010143 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It isn't safe to read the device ID in SOFTWARE_RESET register until the silicon boot sequence has completed. This patch rearranges the code to wait for BOOT_DONE first. If we don't have a GPIO to control hard reset we must issue a soft reset to get the silicon into a known-good booted state before reading the device ID. Signed-off-by: Stuart Henderson Signed-off-by: Richard Fitzgerald --- drivers/mfd/madera-core.c | 33 +++++++++++++++------------------ 1 file changed, 15 insertions(+), 18 deletions(-) diff --git a/drivers/mfd/madera-core.c b/drivers/mfd/madera-core.c index 3ff9a0615658..b9d42edf96c9 100644 --- a/drivers/mfd/madera-core.c +++ b/drivers/mfd/madera-core.c @@ -454,10 +454,23 @@ int madera_dev_init(struct madera *madera) regcache_cache_only(madera->regmap, false); regcache_cache_only(madera->regmap_32bit, false); + /* If we don't have a reset GPIO use a soft reset */ + if (!madera->pdata.reset) { + ret = madera_soft_reset(madera); + if (ret) + goto err_reset; + } + /* - * Now we can power up and verify that this is a chip we know about - * before we start doing any writes to its registers. + * Must wait for internal boot sequence to complete before + * reading the device ID */ + ret = madera_wait_for_boot(madera); + if (ret) { + dev_err(madera->dev, "Device failed initial boot: %d\n", ret); + goto err_reset; + } + ret = regmap_read(madera->regmap, MADERA_SOFTWARE_RESET, &hwid); if (ret) { dev_err(dev, "Failed to read ID register: %d\n", ret); @@ -519,22 +532,6 @@ int madera_dev_init(struct madera *madera) goto err_reset; } - /* - * It looks like a device we support. If we don't have a hard reset - * we can now attempt a soft reset. - */ - if (!madera->pdata.reset) { - ret = madera_soft_reset(madera); - if (ret) - goto err_reset; - } - - ret = madera_wait_for_boot(madera); - if (ret) { - dev_err(madera->dev, "Device failed initial boot: %d\n", ret); - goto err_reset; - } - ret = regmap_read(madera->regmap, MADERA_HARDWARE_REVISION, &madera->rev); if (ret) { -- 2.11.0