From patchwork Fri May 1 13:21:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 226468 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, 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 F25ACC47258 for ; Fri, 1 May 2020 14:01:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3607206D6 for ; Fri, 1 May 2020 14:01:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588341677; bh=U+U2iYpx0DbAp2Qok+ROLY7JqeDXOVnqZQgUxYD8ArQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tdhldhqyM57Ed+ajIbfLUPaImk5AoA9Ct2O8IA6qlEgOJKVqDB4+zo6yP1KMOc9w/ J3WLyi159Q/w06BLhlwFB9UCRExQnKmXuI8B0AdzyrRCYnDUX1hpoUm65PhpyGm1Ze Q6xNA/SmuJ/Qp3qNZWSD+uj9N2s1LXAj31LMv6ms= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729221AbgEAOBR (ORCPT ); Fri, 1 May 2020 10:01:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:47372 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729149AbgEAN0C (ORCPT ); Fri, 1 May 2020 09:26:02 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D8362208D6; Fri, 1 May 2020 13:26:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588339561; bh=U+U2iYpx0DbAp2Qok+ROLY7JqeDXOVnqZQgUxYD8ArQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1IkHQ4plDP+GTX49uu/HvY0JgA0z4l9BZ5+rPYv1GgAKIhoMqEzBUyqzCkXK4iPtc wqRjyxWqSNRVpZE8l8E9wW6IQxgUW8MQX3dM5WgmRTNinYmO7llh6wlsopegsmY4x+ Qno4j55guaHRT0iOYgRSj9KqR8V9qmu6HCwYNedY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Stable@vger.kernel.org, Jonathan Cameron Subject: [PATCH 4.4 28/70] iio: xilinx-xadc: Fix sequencer configuration for aux channels in simultaneous mode Date: Fri, 1 May 2020 15:21:16 +0200 Message-Id: <20200501131523.072180588@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200501131513.302599262@linuxfoundation.org> References: <20200501131513.302599262@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Lars-Peter Clausen commit 8bef455c8b1694547ee59e8b1939205ed9d901a6 upstream. The XADC has two internal ADCs. Depending on the mode it is operating in either one or both of them are used. The device manual calls this continuous (one ADC) and simultaneous (both ADCs) mode. The meaning of the sequencing register for the aux channels changes depending on the mode. In continuous mode each bit corresponds to one of the 16 aux channels. And the single ADC will convert them one by one in order. In simultaneous mode the aux channels are split into two groups the first 8 channels are assigned to the first ADC and the other 8 channels to the second ADC. The upper 8 bits of the sequencing register are unused and the lower 8 bits control both ADCs. This means a bit needs to be set if either the corresponding channel from the first group or the second group (or both) are set. Currently the driver does not have the special handling required for simultaneous mode. Add it. Signed-off-by: Lars-Peter Clausen Fixes: bdc8cda1d010 ("iio:adc: Add Xilinx XADC driver") Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/adc/xilinx-xadc-core.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/iio/adc/xilinx-xadc-core.c +++ b/drivers/iio/adc/xilinx-xadc-core.c @@ -785,6 +785,16 @@ static int xadc_preenable(struct iio_dev if (ret) goto err; + /* + * In simultaneous mode the upper and lower aux channels are samples at + * the same time. In this mode the upper 8 bits in the sequencer + * register are don't care and the lower 8 bits control two channels + * each. As such we must set the bit if either the channel in the lower + * group or the upper group is enabled. + */ + if (seq_mode == XADC_CONF1_SEQ_SIMULTANEOUS) + scan_mask = ((scan_mask >> 8) | scan_mask) & 0xff0000; + ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16); if (ret) goto err;