From patchwork Mon Apr 12 09:34:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacopo Mondi X-Patchwork-Id: 12197439 X-Patchwork-Delegate: kieran@bingham.xyz 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 E07B7C04FE5 for ; Mon, 12 Apr 2021 09:43:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ACB8761248 for ; Mon, 12 Apr 2021 09:43:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239290AbhDLJnm (ORCPT ); Mon, 12 Apr 2021 05:43:42 -0400 Received: from relay12.mail.gandi.net ([217.70.178.232]:41649 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239055AbhDLJgq (ORCPT ); Mon, 12 Apr 2021 05:36:46 -0400 Received: from uno.lan (93-34-118-233.ip49.fastwebnet.it [93.34.118.233]) (Authenticated sender: jacopo@jmondi.org) by relay12.mail.gandi.net (Postfix) with ESMTPSA id 20BBF200018; Mon, 12 Apr 2021 09:34:49 +0000 (UTC) From: Jacopo Mondi To: kieran.bingham+renesas@ideasonboard.com, laurent.pinchart+renesas@ideasonboard.com, niklas.soderlund+renesas@ragnatech.se, geert@linux-m68k.org Cc: Jacopo Mondi , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, Laurent Pinchart Subject: [PATCH v4 15/17] media: i2c: rdacm20: Re-work ov10635 reset Date: Mon, 12 Apr 2021 11:34:49 +0200 Message-Id: <20210412093451.14198-16-jacopo+renesas@jmondi.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210412093451.14198-1-jacopo+renesas@jmondi.org> References: <20210412093451.14198-1-jacopo+renesas@jmondi.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org The OV10635 image sensor embedded in the camera module is currently reset after the MAX9271 initialization with two long delays that were most probably not correctly characterized. Re-work the image sensor reset procedure by holding the chip in reset during the MAX9271 configuration, removing the long sleep delays and only wait after the chip exits from reset for 350-500 microseconds interval, which is larger than the minimum (2048 * (1 / XVCLK)) timeout characterized in the chip manual. Reviewed-by: Kieran Bingham Reviewed-by: Laurent Pinchart Signed-off-by: Jacopo Mondi --- drivers/media/i2c/rdacm20.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/drivers/media/i2c/rdacm20.c b/drivers/media/i2c/rdacm20.c index e6fed86a3281..cb725c2778c0 100644 --- a/drivers/media/i2c/rdacm20.c +++ b/drivers/media/i2c/rdacm20.c @@ -473,6 +473,19 @@ static int rdacm20_initialize(struct rdacm20_device *dev) if (ret) return ret; + /* + * Hold OV10635 in reset during max9271 configuration. The reset signal + * has to be asserted for at least 200 microseconds. + */ + ret = max9271_enable_gpios(&dev->serializer, MAX9271_GPIO1OUT); + if (ret) + return ret; + + ret = max9271_clear_gpios(&dev->serializer, MAX9271_GPIO1OUT); + if (ret) + return ret; + usleep_range(200, 500); + ret = max9271_configure_gmsl_link(&dev->serializer); if (ret) return ret; @@ -487,22 +500,14 @@ static int rdacm20_initialize(struct rdacm20_device *dev) dev->serializer.client->addr = dev->addrs[0]; /* - * Reset the sensor by cycling the OV10635 reset signal connected to the - * MAX9271 GPIO1 and verify communication with the OV10635. + * Release ov10635 from reset and initialize it. The image sensor + * requires at least 2048 XVCLK cycles (85 micro-seconds at 24MHz) + * before being available. Stay safe and wait up to 500 micro-seconds. */ - ret = max9271_enable_gpios(&dev->serializer, MAX9271_GPIO1OUT); - if (ret) - return ret; - - ret = max9271_clear_gpios(&dev->serializer, MAX9271_GPIO1OUT); - if (ret) - return ret; - usleep_range(10000, 15000); - ret = max9271_set_gpios(&dev->serializer, MAX9271_GPIO1OUT); if (ret) return ret; - usleep_range(10000, 15000); + usleep_range(100, 500); again: ret = ov10635_read16(dev, OV10635_PID);