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,URIBL_BLOCKED, 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 412C2C43143 for ; Tue, 2 Oct 2018 10:41:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 11D92204FD for ; Tue, 2 Oct 2018 10:41:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 11D92204FD 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 S1727421AbeJBRYQ (ORCPT ); Tue, 2 Oct 2018 13:24:16 -0400 Received: from mx0a-001ae601.pphosted.com ([67.231.149.25]:34820 "EHLO mx0b-001ae601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727007AbeJBRYP (ORCPT ); Tue, 2 Oct 2018 13:24:15 -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 w92Aee4C030652; Tue, 2 Oct 2018 05:41:36 -0500 Authentication-Results: ppops.net; spf=none smtp.mailfrom=rf@opensource.cirrus.com Received: from mail1.cirrus.com (mail1.cirrus.com [141.131.3.20]) by mx0a-001ae601.pphosted.com with ESMTP id 2mugjdhm6q-1; Tue, 02 Oct 2018 05:41:36 -0500 Received: from EX17.ad.cirrus.com (unknown [172.20.9.81]) by mail1.cirrus.com (Postfix) with ESMTP id 91BD2611C8C1; Tue, 2 Oct 2018 05:41:35 -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; Tue, 2 Oct 2018 11:41:34 +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 w92AfYlG022871; Tue, 2 Oct 2018 11:41:34 +0100 From: Richard Fitzgerald To: CC: , , "Richard Fitzgerald" Subject: [PATCH v2 2/2] mfd: madera: Wait for BOOT_DONE before reading device ID Date: Tue, 2 Oct 2018 11:41:34 +0100 Message-ID: <20181002104134.29003-2-rf@opensource.cirrus.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20181002104134.29003-1-rf@opensource.cirrus.com> References: <20181002104134.29003-1-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-1810020106 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 the SOFTWARE_RESET register until the silicon boot sequence has completed. This patch rearranges the code to wait until BOOT_DONE is set. If we don't have a hard reset line we want to defer writing a soft reset command until we have identified the silicon as something we recognize. As the BOOT_DONE bit is sticky it is safe to wait for it without issuing a soft reset first, because the most recent power-up will have caused a boot sequence and set the bit. Note that the boot sequence is not the same as a reset so we still have to soft reset to get the codec into a known state. Signed-off-by: Stuart Henderson Signed-off-by: Richard Fitzgerald --- drivers/mfd/madera-core.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/mfd/madera-core.c b/drivers/mfd/madera-core.c index 1dedfe68a3dc..e114ca5e6c3f 100644 --- a/drivers/mfd/madera-core.c +++ b/drivers/mfd/madera-core.c @@ -455,10 +455,13 @@ int madera_dev_init(struct madera *madera) regcache_cache_only(madera->regmap, false); regcache_cache_only(madera->regmap_32bit, false); - /* - * Now we can power up and verify that this is a chip we know about - * before we start doing any writes to its registers. - */ + /* BOOT_DONE must be set before we can read 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); @@ -528,12 +531,13 @@ int madera_dev_init(struct madera *madera) 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 = madera_wait_for_boot(madera); + if (ret) { + dev_err(madera->dev, "Device failed initial soft reboot: %d\n", + ret); + goto err_reset; + } } ret = regmap_read(madera->regmap, MADERA_HARDWARE_REVISION, -- 2.11.0