From mboxrd@z Thu Jan 1 00:00:00 1970 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,URIBL_BLOCKED,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 3AC20C433F7 for ; Fri, 19 Mar 2021 16:43:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24D4961990 for ; Fri, 19 Mar 2021 16:43:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231220AbhCSQnD (ORCPT ); Fri, 19 Mar 2021 12:43:03 -0400 Received: from relay6-d.mail.gandi.net ([217.70.183.198]:50443 "EHLO relay6-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230478AbhCSQme (ORCPT ); Fri, 19 Mar 2021 12:42:34 -0400 X-Originating-IP: 5.92.35.220 Received: from uno.localdomain (mob-5-92-35-220.net.vodafone.it [5.92.35.220]) (Authenticated sender: jacopo@jmondi.org) by relay6-d.mail.gandi.net (Postfix) with ESMTPSA id 91D97C000B; Fri, 19 Mar 2021 16:42:29 +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 v3 19/19] media: i2c: rdacm20: Re-work ov10635 reset Date: Fri, 19 Mar 2021 17:41:48 +0100 Message-Id: <20210319164148.199192-20-jacopo+renesas@jmondi.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210319164148.199192-1-jacopo+renesas@jmondi.org> References: <20210319164148.199192-1-jacopo+renesas@jmondi.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 7ed3866b5335..7ba2d0249da8 100644 --- a/drivers/media/i2c/rdacm20.c +++ b/drivers/media/i2c/rdacm20.c @@ -454,6 +454,19 @@ static int rdacm20_init(struct v4l2_subdev *sd, unsigned int val) 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; @@ -468,22 +481,14 @@ static int rdacm20_init(struct v4l2_subdev *sd, unsigned int val) 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); for (i = 0; i < OV10635_PID_TIMEOUT; ++i) { ret = ov10635_read16(dev, OV10635_PID); -- 2.30.0