From patchwork Sun May 21 22:59:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Artur Rojek X-Patchwork-Id: 13249658 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BAA10C77B7C for ; Sun, 21 May 2023 22:59:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229481AbjEUW7y (ORCPT ); Sun, 21 May 2023 18:59:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231329AbjEUW7u (ORCPT ); Sun, 21 May 2023 18:59:50 -0400 Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::225]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B36CBBE; Sun, 21 May 2023 15:59:48 -0700 (PDT) Received: (Authenticated sender: contact@artur-rojek.eu) by mail.gandi.net (Postfix) with ESMTPSA id 6424B1C0003; Sun, 21 May 2023 22:59:45 +0000 (UTC) From: Artur Rojek To: Paul Cercueil , Jonathan Cameron , Dmitry Torokhov , Chris Morgan , Andy Shevchenko Cc: linux-mips@vger.kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, Artur Rojek Subject: [PATCH v2 1/2] iio/adc: ingenic: Fix channel offsets in buffer Date: Mon, 22 May 2023 00:59:00 +0200 Message-Id: <20230521225901.388455-2-contact@artur-rojek.eu> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230521225901.388455-1-contact@artur-rojek.eu> References: <20230521225901.388455-1-contact@artur-rojek.eu> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Consumers expect the buffer to only contain enabled channels. While preparing the buffer, the driver makes two mistakes: 1) It inserts empty data for disabled channels. 2) Each ADC readout contains samples for two 16-bit channels. If either of them is active, the whole 32-bit sample is pushed into the buffer as-is. Both of those issues cause the active channels to appear at the wrong offsets in the buffer. Fix the above by demuxing samples for active channels only. This has remained unnoticed, as all the consumers so far were only using channels 0 and 1, leaving them unaffected by changes introduced in this commit. Signed-off-by: Artur Rojek Tested-by: Paul Cercueil --- v2: - demux active channels from ADC readouts - clarify in the commit description that this patch doesn't impact existing consumers of this driver drivers/iio/adc/ingenic-adc.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/iio/adc/ingenic-adc.c b/drivers/iio/adc/ingenic-adc.c index a7325dbbb99a..093710a7ad4c 100644 --- a/drivers/iio/adc/ingenic-adc.c +++ b/drivers/iio/adc/ingenic-adc.c @@ -802,13 +802,19 @@ static irqreturn_t ingenic_adc_irq(int irq, void *data) struct ingenic_adc *adc = iio_priv(iio_dev); unsigned long mask = iio_dev->active_scan_mask[0]; unsigned int i; - u32 tdat[3]; - - for (i = 0; i < ARRAY_SIZE(tdat); mask >>= 2, i++) { - if (mask & 0x3) - tdat[i] = readl(adc->base + JZ_ADC_REG_ADTCH); - else - tdat[i] = 0; + u16 tdat[6]; + u32 val; + + memset(tdat, 0, ARRAY_SIZE(tdat)); + for (i = 0; mask && i < ARRAY_SIZE(tdat); mask >>= 2) { + if (mask & 0x3) { + val = readl(adc->base + JZ_ADC_REG_ADTCH); + /* Two channels per sample. Demux active. */ + if (mask & BIT(0)) + tdat[i++] = val & 0xffff; + if (mask & BIT(1)) + tdat[i++] = val >> 16; + } } iio_push_to_buffers(iio_dev, tdat);