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=-15.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable 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 A4D26C432BE for ; Sun, 29 Aug 2021 15:32:43 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 38B6060F3A for ; Sun, 29 Aug 2021 15:32:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 38B6060F3A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8oRRss2am3hlzk3lhmflwim1PX0p+s7JArtapdARyXU=; b=E4fngguH3pPozv 9ls3yx6mz8eoGl+7nxJvFquCEQrj+yovGFITPv/V+yyxhDk93qTsD/5HO4BIcNn6yd2kMx0QIEeFY liZSCRaTfbaQHvmiNBwrgu/0G5xXvGgp90VtBGrwGYTRE2DVF7O7/ULWZKS/ZbJELrdscntOx/AhC xgsA53MaRJ+eYkGM8OO3YoInvZdU7upSxucyc2NMXBn3t8XC2w47nA6g2DNR20c/qjKe5yNJQu/X1 8DvTufnTZ3NL1htxyo+R6kCb6ZnmucjYb8UuUb8rRFPMaK/6ZxTjq3nYvcHhVpa7c6cfZVbgO3rRZ sX5lYdSBtduaP/IfIdKQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mKMle-00FhGN-63; Sun, 29 Aug 2021 15:30:42 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mKMla-00FhFS-1u for linux-arm-kernel@lists.infradead.org; Sun, 29 Aug 2021 15:30:39 +0000 Received: from jic23-huawei (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (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 9A7F860F45; Sun, 29 Aug 2021 15:30:32 +0000 (UTC) Date: Sun, 29 Aug 2021 16:33:46 +0100 From: Jonathan Cameron To: Billy Tsai Cc: , , , , , , , , , , , , , Subject: Re: [RESEND v4 11/15] iio: adc: aspeed: Fix the calculate error of clock. Message-ID: <20210829163346.501fdb43@jic23-huawei> In-Reply-To: <20210824091243.9393-12-billy_tsai@aspeedtech.com> References: <20210824091243.9393-1-billy_tsai@aspeedtech.com> <20210824091243.9393-12-billy_tsai@aspeedtech.com> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210829_083038_180668_6E108923 X-CRM114-Status: GOOD ( 22.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 24 Aug 2021 17:12:39 +0800 Billy Tsai wrote: > The adc clcok formula is clock > ast2400/2500: > ADC clock period = PCLK * 2 * (ADC0C[31:17] + 1) * (ADC0C[9:0] + 1) > ast2600: > ADC clock period = PCLK * 2 * (ADC0C[15:0] + 1) > They all have one fixed divided 2 and the legacy driver didn't handle it. > This patch register the fixed factory clock device as the parent of adc > clock scaler to fix this issue. What are the impacts of this being wrong before? Is this something we should look to backport? Comment inline. > > Signed-off-by: Billy Tsai > --- > drivers/iio/adc/aspeed_adc.c | 26 ++++++++++++++++++++++++++ > 1 file changed, 26 insertions(+) > > diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c > index ea3e9a52fcc9..8fe7da1a651f 100644 > --- a/drivers/iio/adc/aspeed_adc.c > +++ b/drivers/iio/adc/aspeed_adc.c > @@ -4,6 +4,12 @@ > * > * Copyright (C) 2017 Google, Inc. > * Copyright (C) 2021 Aspeed Technology Inc. > + * > + * ADC clock formula: > + * Ast2400/Ast2500: > + * clock period = period of PCLK * 2 * (ADC0C[31:17] + 1) * (ADC0C[9:0] + 1) > + * Ast2600: > + * clock period = period of PCLK * 2 * (ADC0C[15:0] + 1) > */ > > #include > @@ -77,6 +83,7 @@ struct aspeed_adc_data { > struct regulator *regulator; > void __iomem *base; > spinlock_t clk_lock; > + struct clk_hw *fixed_div_clk; > struct clk_hw *clk_prescaler; > struct clk_hw *clk_scaler; > struct reset_control *rst; > @@ -196,6 +203,13 @@ static void aspeed_adc_unregister_divider(void *data) > clk_hw_unregister_divider(clk); > } > > +static void aspeed_adc_unregister_fixed_divider(void *data) > +{ > + struct clk_hw *clk = data; > + > + clk_hw_unregister_fixed_factor(clk); > +} > + > static void aspeed_adc_reset_assert(void *data) > { > struct reset_control *rst = data; > @@ -312,6 +326,18 @@ static int aspeed_adc_probe(struct platform_device *pdev) > /* Register ADC clock prescaler with source specified by device tree. */ > spin_lock_init(&data->clk_lock); > snprintf(clk_parent_name, 32, of_clk_get_parent_name(pdev->dev.of_node, 0)); > + snprintf(clk_name, 32, "%s-fixed-div", data->model_data->model_name); ARRAY_SIZE > + data->fixed_div_clk = clk_hw_register_fixed_factor( > + &pdev->dev, clk_name, clk_parent_name, 0, 1, 2); > + if (IS_ERR(data->fixed_div_clk)) > + return PTR_ERR(data->fixed_div_clk); > + > + ret = devm_add_action_or_reset(data->dev, > + aspeed_adc_unregister_fixed_divider, > + data->clk_prescaler); > + if (ret) > + return ret; > + snprintf(clk_parent_name, 32, clk_name); > if (data->model_data->need_prescaler) { > snprintf(clk_name, 32, "%s-prescaler", > data->model_data->model_name); _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel