From patchwork Wed Feb 4 16:48:14 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sifan Naeem X-Patchwork-Id: 5778161 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 3D4D69F269 for ; Wed, 4 Feb 2015 16:47:13 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 53E6D20259 for ; Wed, 4 Feb 2015 16:47:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 51B572024F for ; Wed, 4 Feb 2015 16:47:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966953AbbBDQqy (ORCPT ); Wed, 4 Feb 2015 11:46:54 -0500 Received: from mailapp01.imgtec.com ([195.59.15.196]:25854 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966331AbbBDQqx (ORCPT ); Wed, 4 Feb 2015 11:46:53 -0500 Received: from KLMAIL01.kl.imgtec.org (unknown [192.168.5.35]) by Websense Email Security Gateway with ESMTPS id 8FD11D070F60C; Wed, 4 Feb 2015 16:46:48 +0000 (GMT) Received: from hhmail02.hh.imgtec.org (10.100.10.20) by KLMAIL01.kl.imgtec.org (192.168.5.35) with Microsoft SMTP Server (TLS) id 14.3.195.1; Wed, 4 Feb 2015 16:46:51 +0000 Received: from iw-build-3.kl.imgtec.org (192.168.167.63) by hhmail02.hh.imgtec.org (10.100.10.20) with Microsoft SMTP Server (TLS) id 14.3.224.2; Wed, 4 Feb 2015 16:46:51 +0000 From: Sifan Naeem To: , CC: , , Sifan Naeem Subject: [PATCH v2] rc: img-ir: Add and enable sys clock for img-ir Date: Wed, 4 Feb 2015 16:48:14 +0000 Message-ID: <1423068494-9360-1-git-send-email-sifan.naeem@imgtec.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-Originating-IP: [192.168.167.63] Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Gets a handle to the system clock, already described in the binding document, and calls the appropriate common clock framework functions to mark it prepared/enabled, the common clock framework initially enables the clock and doesn't disable it at least until the device/driver is removed. It's important the systen clock is enabled before register interface is accessed by the driver. The system clock to IR is needed for the driver to communicate with the IR hardware via MMIO accesses on the system bus, so it must not be disabled during use or the driver will malfunction. Signed-off-by: Sifan Naeem Acked-by: James Hogan --- Changes from v1: System clock enabled in probe function before any hardware is accessed. Error handling in probe function ensures ISR doesn't get called with system clock disabled. drivers/media/rc/img-ir/img-ir-core.c | 29 +++++++++++++++++++++++++---- drivers/media/rc/img-ir/img-ir.h | 2 ++ 2 files changed, 27 insertions(+), 4 deletions(-) diff --git a/drivers/media/rc/img-ir/img-ir-core.c b/drivers/media/rc/img-ir/img-ir-core.c index 77c78de..a10d666 100644 --- a/drivers/media/rc/img-ir/img-ir-core.c +++ b/drivers/media/rc/img-ir/img-ir-core.c @@ -110,16 +110,32 @@ static int img_ir_probe(struct platform_device *pdev) priv->clk = devm_clk_get(&pdev->dev, "core"); if (IS_ERR(priv->clk)) dev_warn(&pdev->dev, "cannot get core clock resource\n"); + + /* Get sys clock */ + priv->sys_clk = devm_clk_get(&pdev->dev, "sys"); + if (IS_ERR(priv->sys_clk)) + dev_warn(&pdev->dev, "cannot get sys clock resource\n"); /* - * The driver doesn't need to know about the system ("sys") or power - * modulation ("mod") clocks yet + * Enabling the system clock before the register interface is + * accessed. ISR shouldn't get called with Sys Clock disabled, + * hence exiting probe with an error. */ + if (!IS_ERR(priv->sys_clk)) { + error = clk_prepare_enable(priv->sys_clk); + if (error) { + dev_err(&pdev->dev, "cannot enable sys clock\n"); + return error; + } + } /* Set up raw & hw decoder */ error = img_ir_probe_raw(priv); error2 = img_ir_probe_hw(priv); - if (error && error2) - return (error == -ENODEV) ? error2 : error; + if (error && error2) { + if (error == -ENODEV) + error = error2; + goto err_probe; + } /* Get the IRQ */ priv->irq = irq; @@ -139,6 +155,9 @@ static int img_ir_probe(struct platform_device *pdev) err_irq: img_ir_remove_hw(priv); img_ir_remove_raw(priv); +err_probe: + if (!IS_ERR(priv->sys_clk)) + clk_disable_unprepare(priv->sys_clk); return error; } @@ -152,6 +171,8 @@ static int img_ir_remove(struct platform_device *pdev) if (!IS_ERR(priv->clk)) clk_disable_unprepare(priv->clk); + if (!IS_ERR(priv->sys_clk)) + clk_disable_unprepare(priv->sys_clk); return 0; } diff --git a/drivers/media/rc/img-ir/img-ir.h b/drivers/media/rc/img-ir/img-ir.h index 2ddf560..f1387c0 100644 --- a/drivers/media/rc/img-ir/img-ir.h +++ b/drivers/media/rc/img-ir/img-ir.h @@ -138,6 +138,7 @@ struct clk; * @dev: Platform device. * @irq: IRQ number. * @clk: Input clock. + * @sys_clk: System clock. * @reg_base: Iomem base address of IR register block. * @lock: Protects IR registers and variables in this struct. * @raw: Driver data for raw decoder. @@ -147,6 +148,7 @@ struct img_ir_priv { struct device *dev; int irq; struct clk *clk; + struct clk *sys_clk; void __iomem *reg_base; spinlock_t lock;