From patchwork Tue Oct 10 02:46:37 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wenyou.Yang@microchip.com X-Patchwork-Id: 9994813 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 86E1C60230 for ; Tue, 10 Oct 2017 02:50:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 768AC25F31 for ; Tue, 10 Oct 2017 02:50:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6B68125E13; Tue, 10 Oct 2017 02:50:53 +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=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=unavailable 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 E864225EA6 for ; Tue, 10 Oct 2017 02:50:52 +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=dfY1gVpRSBSVE4I9OPTA1V383Fs3ZFRLKfoqLYHu6WM=; b=gURdqDxTk7Iedx chrs9MmlcoRjdSe9+tCPuDYJ9DyRfPAFORPkKhVmab1ot+BbdgZk+nzOR62YqpuId0Pe1FlRG2pTQ ADHxeiRFZKEMa3L60z4po/mOkHvWmqLf/8Bk3rVtXghCisUmCQhvg9wEfRc3wp+GcFbv8yLxy21GU JfphrNsBiizT0BYqrmTHPeRbwBGIKKjgtfJ/U2rJ4Q6YoaQwCshPDFtylgc+Eu9sNIP36nNDYw04y mJ/tiyi+tqAc+yA83udphUPm1yF3zs50JcGASNeUMehykM6iXFNXfBnUxNmxQ+UbqszZTytJw80/g Mx5b1r0dtMnQrfPzd6sA==; 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 1e1kdA-0003CO-Db; Tue, 10 Oct 2017 02:50:52 +0000 Received: from nasmtp01.atmel.com ([192.199.1.246] helo=DVREDG02.corp.atmel.com) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1e1kcz-0002pp-4b for linux-arm-kernel@lists.infradead.org; Tue, 10 Oct 2017 02:50:50 +0000 Received: from apsmtp01.atmel.com (10.168.254.30) by DVREDG02.corp.atmel.com (10.42.103.31) with Microsoft SMTP Server (TLS) id 14.3.235.1; Mon, 9 Oct 2017 20:50:16 -0600 Received: from shaarm01.corp.atmel.com (10.168.254.13) by apsmtp01.corp.atmel.com (10.168.254.30) with Microsoft SMTP Server id 14.3.235.1; Tue, 10 Oct 2017 10:54:59 +0800 From: Wenyou Yang To: Mauro Carvalho Chehab Subject: [PATCH v4 2/5] media: atmel-isc: Add prepare and unprepare ops Date: Tue, 10 Oct 2017 10:46:37 +0800 Message-ID: <20171010024640.5733-3-wenyou.yang@microchip.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20171010024640.5733-1-wenyou.yang@microchip.com> References: <20171010024640.5733-1-wenyou.yang@microchip.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20171009_195041_439073_26DDB32D X-CRM114-Status: GOOD ( 10.47 ) 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: Wenyou Yang , Jonathan Corbet , linux-kernel@vger.kernel.org, Hans Verkuil , Sakari Ailus , linux-arm-kernel@lists.infradead.org, Linux Media Mailing List 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 A software write operation to the ISC_CLKEN or ISC_CLKDIS register requires double clock domain synchronization and is not permitted when the ISC_SR.SIP is asserted. So add the .prepare and .unprepare ops to make sure the ISC_CLKSR.SIP is unasserted before the write operation to the ISC_CLKEN or ISC_CLKDIS register. Signed-off-by: Wenyou Yang --- Changes in v4: - Call pm_runtime_get_sync() and pm_runtime_put_sync() in ->prepare and ->unprepare callback. Changes in v3: None Changes in v2: None drivers/media/platform/atmel/atmel-isc-regs.h | 1 + drivers/media/platform/atmel/atmel-isc.c | 40 +++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/drivers/media/platform/atmel/atmel-isc-regs.h b/drivers/media/platform/atmel/atmel-isc-regs.h index 6936ac467609..93e58fcf1d5f 100644 --- a/drivers/media/platform/atmel/atmel-isc-regs.h +++ b/drivers/media/platform/atmel/atmel-isc-regs.h @@ -42,6 +42,7 @@ /* ISC Clock Status Register */ #define ISC_CLKSR 0x00000020 +#define ISC_CLKSR_SIP BIT(31) #define ISC_CLK(n) BIT(n) diff --git a/drivers/media/platform/atmel/atmel-isc.c b/drivers/media/platform/atmel/atmel-isc.c index 991f962b7023..5f8228fc9c8d 100644 --- a/drivers/media/platform/atmel/atmel-isc.c +++ b/drivers/media/platform/atmel/atmel-isc.c @@ -308,6 +308,44 @@ module_param(sensor_preferred, uint, 0644); MODULE_PARM_DESC(sensor_preferred, "Sensor is preferred to output the specified format (1-on 0-off), default 1"); +static int isc_wait_clk_stable(struct clk_hw *hw) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + struct regmap *regmap = isc_clk->regmap; + unsigned long timeout = jiffies + usecs_to_jiffies(1000); + unsigned int status; + + while (time_before(jiffies, timeout)) { + regmap_read(regmap, ISC_CLKSR, &status); + if (!(status & ISC_CLKSR_SIP)) + return 0; + + usleep_range(10, 250); + } + + return -ETIMEDOUT; +} + +static int isc_clk_prepare(struct clk_hw *hw) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + + if (isc_clk->id == ISC_MCK) + pm_runtime_get_sync(isc_clk->dev); + + return isc_wait_clk_stable(hw); +} + +static void isc_clk_unprepare(struct clk_hw *hw) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + + isc_wait_clk_stable(hw); + + if (isc_clk->id == ISC_MCK) + pm_runtime_put_sync(isc_clk->dev); +} + static int isc_clk_enable(struct clk_hw *hw) { struct isc_clk *isc_clk = to_isc_clk(hw); @@ -459,6 +497,8 @@ static int isc_clk_set_rate(struct clk_hw *hw, } static const struct clk_ops isc_clk_ops = { + .prepare = isc_clk_prepare, + .unprepare = isc_clk_unprepare, .enable = isc_clk_enable, .disable = isc_clk_disable, .is_enabled = isc_clk_is_enabled,