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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9D6DC433F5 for ; Fri, 1 Apr 2022 10:17:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245247AbiDAKTK (ORCPT ); Fri, 1 Apr 2022 06:19:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245095AbiDAKTI (ORCPT ); Fri, 1 Apr 2022 06:19:08 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 00F3426B39F for ; Fri, 1 Apr 2022 03:17:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A342AB82361 for ; Fri, 1 Apr 2022 10:17:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0580C340F2; Fri, 1 Apr 2022 10:17:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1648808236; bh=NJ8PIsIBJnWx0oW0WAHjSvQIFLGdD/hojNWCcYVyc94=; h=Subject:To:Cc:From:Date:From; b=pqCPnKQ3gkqhJawI7+/1Az9zSnxD7QSlUJEcz/v+6vVW9oZWAaBXWELW1N9o3wl4Z kTIQt3grLmV556/CZowja6S3QKQq/YRl3Gs9c0N8WUA6IEVocd6k+mIYTREzTJOdKE /Ucnv2rlJzQ2MRBYpx/hWAJMRl2CapM66ZwAMH90= Subject: FAILED: patch "[PATCH] iio: adc: aspeed: Add divider flag to fix incorrect voltage" failed to apply to 5.10-stable tree To: billy_tsai@aspeedtech.com, Jonathan.Cameron@huawei.com, Stable@vger.kernel.org, joel@jms.id.au, kitsok@yandex-team.ru Cc: From: Date: Fri, 01 Apr 2022 12:17:05 +0200 Message-ID: <1648808225149203@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 571426631acf46e2999c7ecd1e9d048172969a43 Mon Sep 17 00:00:00 2001 From: Billy Tsai Date: Mon, 21 Feb 2022 09:27:05 +0800 Subject: [PATCH] iio: adc: aspeed: Add divider flag to fix incorrect voltage reading. The formula for the ADC sampling period in ast2400/ast2500 is: ADC clock period = PCLK * 2 * (ADC0C[31:17] + 1) * (ADC0C[9:0]) When ADC0C[9:0] is set to 0 the sampling voltage will be lower than expected, because the hardware may not have enough time to charge/discharge to a stable voltage. This patch use the flag CLK_DIVIDER_ONE_BASED which will use the raw value read from the register, with the value of zero considered invalid to conform to the corrected formula. Fixes: 573803234e72 ("iio: Aspeed ADC") Reported-by: Konstantin Klubnichkin Signed-off-by: Billy Tsai Reviewed-by: Joel Stanley Link: https://lore.kernel.org/r/20220221012705.22008-1-billy_tsai@aspeedtech.com Cc: Signed-off-by: Jonathan Cameron diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c index e939b84cbb56..0793d2474cdc 100644 --- a/drivers/iio/adc/aspeed_adc.c +++ b/drivers/iio/adc/aspeed_adc.c @@ -539,7 +539,9 @@ static int aspeed_adc_probe(struct platform_device *pdev) data->clk_scaler = devm_clk_hw_register_divider( &pdev->dev, clk_name, clk_parent_name, scaler_flags, data->base + ASPEED_REG_CLOCK_CONTROL, 0, - data->model_data->scaler_bit_width, 0, &data->clk_lock); + data->model_data->scaler_bit_width, + data->model_data->need_prescaler ? CLK_DIVIDER_ONE_BASED : 0, + &data->clk_lock); if (IS_ERR(data->clk_scaler)) return PTR_ERR(data->clk_scaler);