From patchwork Fri May 19 12:45:27 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabrice Gasnier X-Patchwork-Id: 9737085 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 11E1D601A1 for ; Fri, 19 May 2017 12:47:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 03E4D28929 for ; Fri, 19 May 2017 12:47:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EB2F428930; Fri, 19 May 2017 12:47:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9944D28929 for ; Fri, 19 May 2017 12:47:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=aHP6SQAKXy0JiXs573Joh36WawLCQ3n95Wyu3BD1aHw=; b=k+IBGUhj9sOth8 QCbEBsXpNNq7ADIjEPBWJW1Rq64fo9uiygbH9XhzS+y4kRbAszO+BMFlWJqUcGPU0fenmxvnGaovH U5B3Lhzqrcl7+cSl1BUIitpSsLbiMoes+H6qdGCAH7A5o69IaL3fjvyZzMG+SlTPKK9OogTfa7fOD fOrUcaTuISCPMzskEUa8Z37gfwK3mULt/lagoqQ1vlDzAEv/2bD9yGJ3XO0SaVy7wOmSI1IB0Njql lH1YDYC1jSiO5wMchF+GToMwrC7AW3rZHjwpzBasf6vTGQA0DBSRV8SYklPQgs+FrDm7O05czLQCc GWbHqP3wYA0HXP4AL/wA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dBhJI-0002sd-C5; Fri, 19 May 2017 12:47:12 +0000 Received: from mx08-00178001.pphosted.com ([91.207.212.93] helo=mx07-00178001.pphosted.com) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dBhIZ-0001zH-4R for linux-arm-kernel@lists.infradead.org; Fri, 19 May 2017 12:46:31 +0000 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx08-.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v4JCi790002258; Fri, 19 May 2017 14:45:46 +0200 Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx08-.pphosted.com with ESMTP id 2ahef0n76q-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Fri, 19 May 2017 14:45:46 +0200 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id F407838; Fri, 19 May 2017 12:45:45 +0000 (GMT) Received: from Webmail-eu.st.com (sfhdag5node3.st.com [10.75.127.15]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id CCD6C159A; Fri, 19 May 2017 12:45:45 +0000 (GMT) Received: from localhost (10.75.127.47) by SFHDAG5NODE3.st.com (10.75.127.15) with Microsoft SMTP Server (TLS) id 15.0.1178.4; Fri, 19 May 2017 14:45:45 +0200 From: Fabrice Gasnier To: , , , , , Subject: [PATCH 4/5] iio: adc: stm32: make per instance bus clock optional Date: Fri, 19 May 2017 14:45:27 +0200 Message-ID: <1495197928-1439-5-git-send-email-fabrice.gasnier@st.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1495197928-1439-1-git-send-email-fabrice.gasnier@st.com> References: <1495197928-1439-1-git-send-email-fabrice.gasnier@st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.47] X-ClientProxiedBy: SFHDAG6NODE2.st.com (10.75.127.17) To SFHDAG5NODE3.st.com (10.75.127.15) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-05-19_08:, , signatures=0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170519_054627_521847_9C2025F2 X-CRM114-Status: GOOD ( 12.98 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, benjamin.gaignard@linaro.org, lars@metafoo.de, alexandre.torgue@st.com, linux-iio@vger.kernel.org, pmeerw@pmeerw.net, mcoquelin.stm32@gmail.com, knaack.h@gmx.de, fabrice.gasnier@st.com, benjamin.gaignard@st.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP STM32F4 requires one clock per ADC instance for register access. But, newer version of ADC hardware block have common bus clock for all instances (per instance driver isn't responsible for getting it). So, make it optional by default. Still, enforce it's required on STM32F4. Signed-off-by: Fabrice Gasnier --- drivers/iio/adc/stm32-adc.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 065189a..ad8fdb9 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -160,6 +160,7 @@ struct stm32_adc_regspec { * @regs: registers descriptions * @adc_info: per instance input channels definitions * @trigs: external trigger sources + * @clk_required: clock is required * @start_conv: routine to start conversions * @stop_conv: routine to stop conversions */ @@ -167,6 +168,7 @@ struct stm32_adc_cfg { const struct stm32_adc_regspec *regs; const struct stm32_adc_info *adc_info; struct stm32_adc_trig_info *trigs; + bool clk_required; void (*start_conv)(struct stm32_adc *, bool dma); void (*stop_conv)(struct stm32_adc *); }; @@ -1142,14 +1144,21 @@ static int stm32_adc_probe(struct platform_device *pdev) adc->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(adc->clk)) { - dev_err(&pdev->dev, "Can't get clock\n"); - return PTR_ERR(adc->clk); + ret = PTR_ERR(adc->clk); + if (ret == -ENOENT && !adc->cfg->clk_required) { + adc->clk = NULL; + } else { + dev_err(&pdev->dev, "Can't get clock\n"); + return ret; + } } - ret = clk_prepare_enable(adc->clk); - if (ret < 0) { - dev_err(&pdev->dev, "clk enable failed\n"); - return ret; + if (adc->clk) { + ret = clk_prepare_enable(adc->clk); + if (ret < 0) { + dev_err(&pdev->dev, "clk enable failed\n"); + return ret; + } } ret = stm32_adc_of_get_resolution(indio_dev); @@ -1193,7 +1202,8 @@ static int stm32_adc_probe(struct platform_device *pdev) dma_release_channel(adc->dma_chan); } err_clk_disable: - clk_disable_unprepare(adc->clk); + if (adc->clk) + clk_disable_unprepare(adc->clk); return ret; } @@ -1211,7 +1221,8 @@ static int stm32_adc_remove(struct platform_device *pdev) adc->rx_buf, adc->rx_dma_buf); dma_release_channel(adc->dma_chan); } - clk_disable_unprepare(adc->clk); + if (adc->clk) + clk_disable_unprepare(adc->clk); return 0; } @@ -1220,6 +1231,7 @@ static int stm32_adc_remove(struct platform_device *pdev) .regs = &stm32f4_adc_regspec, .adc_info = &stm32f4_adc_info, .trigs = stm32f4_adc_trigs, + .clk_required = true, .start_conv = stm32f4_adc_start_conv, .stop_conv = stm32f4_adc_stop_conv, };