From patchwork Mon Jul 19 08:06:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Billy Tsai X-Patchwork-Id: 12384975 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=-18.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 19FE7C12002 for ; Mon, 19 Jul 2021 08:12:10 +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 D105661175 for ; Mon, 19 Jul 2021 08:12:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D105661175 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=aspeedtech.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@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:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=yyiZee5WNy14/nXF6ASEQG3kibwmvZiVDsX4mq3m76g=; b=1SA7vn83bdpNi0 FGdQCfHAclFUMJHjR/9awYrHD6K/EEgILpB+0PjE/Z4nqsA87JuhhVGMsEUje08wbQsSHgrp3meyq rbEWGjSSsHJQIFNzMFFGkRtQ6pcf+m6n+a2orLLqa0FI4OPxVTTEXpp0Gy9kRQMqj64UyYUn+GOA/ v0ubv8WS6dePpg0QKI3Z7NBhs286j/+BOo8Z2mWZO2jID/UOYSc9QsvdQ7etXKcK2zUt/Qjn1JwTp bNIHKk0K4hnhE6YfKc28lTmUR5Fhsbqia0LZbX77KmlQS4oB4LoADbkeM+UwP0jc0sEb59YHK5DId s2Xo9/71YZdPhd9qL8Vw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m5OLk-008kzL-0d; Mon, 19 Jul 2021 08:10:04 +0000 Received: from twspam01.aspeedtech.com ([211.20.114.71]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m5OIH-008jqx-U8 for linux-arm-kernel@lists.infradead.org; Mon, 19 Jul 2021 08:06:31 +0000 Received: from mail.aspeedtech.com ([192.168.0.24]) by twspam01.aspeedtech.com with ESMTP id 16J7nREM015324; Mon, 19 Jul 2021 15:49:27 +0800 (GMT-8) (envelope-from billy_tsai@aspeedtech.com) Received: from BillyTsai-pc.aspeed.com (192.168.2.149) by TWMBX02.aspeed.com (192.168.0.24) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 19 Jul 2021 16:05:48 +0800 From: Billy Tsai To: , , , , , , , , , , , , CC: Subject: [v1 5/7] iio: adc: aspeed: Add func to set sampling rate. Date: Mon, 19 Jul 2021 16:06:05 +0800 Message-ID: <20210719080607.28712-6-billy_tsai@aspeedtech.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210719080607.28712-1-billy_tsai@aspeedtech.com> References: <20210719080607.28712-1-billy_tsai@aspeedtech.com> MIME-Version: 1.0 X-Originating-IP: [192.168.2.149] X-ClientProxiedBy: TWMBX02.aspeed.com (192.168.0.24) To TWMBX02.aspeed.com (192.168.0.24) X-DNSRBL: X-MAIL: twspam01.aspeedtech.com 16J7nREM015324 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210719_010630_329525_12C288C6 X-CRM114-Status: GOOD ( 15.77 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add the function to set the sampling rate and keep the sampling period for a driver used to wait the lastest value. Signed-off-by: Billy Tsai --- drivers/iio/adc/aspeed_adc.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c index 6a77ac4e7dcb..b33ff9f0a3af 100644 --- a/drivers/iio/adc/aspeed_adc.c +++ b/drivers/iio/adc/aspeed_adc.c @@ -55,6 +55,7 @@ #define ASPEED_ADC_INIT_POLLING_TIME 500 #define ASPEED_ADC_INIT_TIMEOUT 500000 +#define ASPEED_ADC_DEF_SAMPLING_RATE 250000 enum aspeed_adc_version { aspeed_adc_ast2400, @@ -77,6 +78,7 @@ struct aspeed_adc_data { struct clk_hw *clk_scaler; struct reset_control *rst; int vref; + u32 sample_period_ns; }; #define ASPEED_CHAN(_idx, _data_reg_addr) { \ @@ -108,6 +110,26 @@ static const struct iio_chan_spec aspeed_adc_iio_channels[] = { ASPEED_CHAN(15, 0x2E), }; +static int aspeed_adc_set_sampling_rate(struct iio_dev *indio_dev, u32 rate) +{ + struct aspeed_adc_data *data = iio_priv(indio_dev); + const struct aspeed_adc_model_data *model_data = + of_device_get_match_data(data->dev); + + if (rate < model_data->min_sampling_rate || + rate > model_data->max_sampling_rate) + return -EINVAL; + /* Each sampling needs 12 clocks to covert.*/ + clk_set_rate(data->clk_scaler->clk, rate * ASPEED_CLOCKS_PER_SAMPLE); + + rate = clk_get_rate(data->clk_scaler->clk); + data->sample_period_ns = DIV_ROUND_UP_ULL( + (u64)NSEC_PER_SEC * ASPEED_CLOCKS_PER_SAMPLE, rate); + dev_dbg(data->dev, "Adc clock = %d sample period = %d ns", rate, + data->sample_period_ns); + return 0; +} + static int aspeed_adc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) @@ -138,19 +160,9 @@ static int aspeed_adc_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { - struct aspeed_adc_data *data = iio_priv(indio_dev); - const struct aspeed_adc_model_data *model_data = - of_device_get_match_data(data->dev); - switch (mask) { case IIO_CHAN_INFO_SAMP_FREQ: - if (val < model_data->min_sampling_rate || - val > model_data->max_sampling_rate) - return -EINVAL; - - clk_set_rate(data->clk_scaler->clk, - val * ASPEED_CLOCKS_PER_SAMPLE); - return 0; + return aspeed_adc_set_sampling_rate(indio_dev, val); case IIO_CHAN_INFO_SCALE: case IIO_CHAN_INFO_RAW: @@ -325,6 +337,7 @@ static int aspeed_adc_probe(struct platform_device *pdev) ret = clk_prepare_enable(data->clk_scaler->clk); if (ret) goto clk_enable_error; + aspeed_adc_set_sampling_rate(indio_dev, ASPEED_ADC_DEF_SAMPLING_RATE); adc_engine_control_reg_val = readl(data->base + ASPEED_REG_ENGINE_CONTROL); /* Start all channels in normal mode. */