From patchwork Tue Feb 23 16:44:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Tachici X-Patchwork-Id: 12100601 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=-11.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, 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 F4121C433DB for ; Tue, 23 Feb 2021 16:37:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B434964D99 for ; Tue, 23 Feb 2021 16:37:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233538AbhBWQhT (ORCPT ); Tue, 23 Feb 2021 11:37:19 -0500 Received: from mx0a-00128a01.pphosted.com ([148.163.135.77]:60908 "EHLO mx0a-00128a01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233312AbhBWQhS (ORCPT ); Tue, 23 Feb 2021 11:37:18 -0500 Received: from pps.filterd (m0167088.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 11NGTeqS004231; Tue, 23 Feb 2021 11:36:34 -0500 Received: from nwd2mta4.analog.com ([137.71.173.58]) by mx0a-00128a01.pphosted.com with ESMTP id 36tw5bk6t3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 23 Feb 2021 11:36:34 -0500 Received: from SCSQMBX11.ad.analog.com (SCSQMBX11.ad.analog.com [10.77.17.10]) by nwd2mta4.analog.com (8.14.7/8.14.7) with ESMTP id 11NGaXZN003439 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 23 Feb 2021 11:36:33 -0500 Received: from SCSQCASHYB7.ad.analog.com (10.77.17.133) by SCSQMBX11.ad.analog.com (10.77.17.10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.721.2; Tue, 23 Feb 2021 08:36:31 -0800 Received: from SCSQMBX10.ad.analog.com (10.77.17.5) by SCSQCASHYB7.ad.analog.com (10.77.17.133) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.721.2; Tue, 23 Feb 2021 08:36:31 -0800 Received: from zeus.spd.analog.com (10.66.68.11) by scsqmbx10.ad.analog.com (10.77.17.5) with Microsoft SMTP Server id 15.2.721.2 via Frontend Transport; Tue, 23 Feb 2021 08:36:31 -0800 Received: from localhost.localdomain ([10.48.65.12]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 11NGaTkp030454; Tue, 23 Feb 2021 11:36:30 -0500 From: To: , CC: Subject: [PATCH v3 0/1] iio: adc: ad7124: allow more than 8 channels Date: Tue, 23 Feb 2021 18:44:03 +0200 Message-ID: <20210223164404.93540-1-alexandru.tachici@analog.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-02-23_08:2021-02-23,2021-02-23 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 suspectscore=0 spamscore=0 lowpriorityscore=0 mlxlogscore=864 phishscore=0 mlxscore=0 bulkscore=0 priorityscore=1501 impostorscore=0 adultscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2102230138 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org From: Alexandru Tachici Currently AD7124-8 driver cannot use more than 8 IIO channels because it was assigning the channel configurations bijectively to channels specified in the device-tree. This is not possible to do when using more than 8 channels as AD7124-8 has only 8 configuration registers. All configurations are marked as live if they are programmed on the device. Any change that happens from userspace (sampling rate, filters etc.) will invalidate them. To allow the user to use all channels at once the driver will keep in memory configurations for all channels but will program only 8 of them at a time on the device. If multiple channels have the same configuration, only one configuration register will be used. If there are more configurations needed than available registers only the last 8 used configurations will be allowed to exist on the device in a LRU fashion. (in case of raw reads). If a read is requested on a channel whose configuration is not programmed: - check if there are similar configurations already programmed if yes: - point channel to that config if no: - check if there are empty config slots - if yes: write config, push into queue of LRU configs - if no: pop one config, get it's config slot nr, write new config on the old slot, push new config in queue of LRU configs. Alexandru Tachici (1): iio: adc: ad7124: allow more than 8 channels drivers/iio/adc/ad7124.c | 461 ++++++++++++++++++++++++++------------- 1 file changed, 308 insertions(+), 153 deletions(-)