From patchwork Mon Mar 1 16:15:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Tachici X-Patchwork-Id: 12110125 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=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,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 67706C433E6 for ; Mon, 1 Mar 2021 16:11:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2259164E04 for ; Mon, 1 Mar 2021 16:11:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237610AbhCAQK5 (ORCPT ); Mon, 1 Mar 2021 11:10:57 -0500 Received: from mx0a-00128a01.pphosted.com ([148.163.135.77]:24618 "EHLO mx0a-00128a01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237543AbhCAQIw (ORCPT ); Mon, 1 Mar 2021 11:08:52 -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 121Fxxh2028961; Mon, 1 Mar 2021 11:08:06 -0500 Received: from nwd2mta4.analog.com ([137.71.173.58]) by mx0a-00128a01.pphosted.com with ESMTP id 36ygt9rt5t-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 01 Mar 2021 11:08:06 -0500 Received: from ASHBMBX8.ad.analog.com (ASHBMBX8.ad.analog.com [10.64.17.5]) by nwd2mta4.analog.com (8.14.7/8.14.7) with ESMTP id 121G85M2057575 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 1 Mar 2021 11:08:05 -0500 Received: from ASHBMBX8.ad.analog.com (10.64.17.5) by ASHBMBX8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.721.2; Mon, 1 Mar 2021 11:08:04 -0500 Received: from zeus.spd.analog.com (10.66.68.11) by ashbmbx8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server id 15.2.721.2 via Frontend Transport; Mon, 1 Mar 2021 11:08:04 -0500 Received: from localhost.localdomain ([10.48.65.12]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 121G82ls012423; Mon, 1 Mar 2021 11:08:03 -0500 From: To: , , CC: , Subject: [PATCH v4 0/1] iio: adc: ad7124: allow more than 8 channels Date: Mon, 1 Mar 2021 18:15:25 +0200 Message-ID: <20210301161526.72884-1-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=2021-03-01_11:2021-03-01,2021-03-01 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 malwarescore=0 impostorscore=0 suspectscore=0 spamscore=0 lowpriorityscore=0 clxscore=1011 adultscore=0 bulkscore=0 mlxscore=0 priorityscore=1501 mlxlogscore=889 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103010132 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 Changelog v3 -> v4: - fixed multi-line comments - moved locking and unlocking out of the switch/case in write_raw - check if there were any actual changes in write_raw to the sample frequency/filter/scale by comparing old/new values before marking a config. as changed - maintain a bitmap in order to keep track of empty slots on the device drivers/iio/adc/ad7124.c | 470 ++++++++++++++++++++++++++------------- 1 file changed, 313 insertions(+), 157 deletions(-)