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 07C73C432C3 for ; Tue, 16 Feb 2021 17:42:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C8B0264DA1 for ; Tue, 16 Feb 2021 17:42:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231244AbhBPRmt (ORCPT ); Tue, 16 Feb 2021 12:42:49 -0500 Received: from relay12.mail.gandi.net ([217.70.178.232]:48205 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231131AbhBPRmQ (ORCPT ); Tue, 16 Feb 2021 12:42:16 -0500 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 2AC8A200002; Tue, 16 Feb 2021 17:41:27 +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 Subject: [PATCH 01/16] media: i2c: rdacm20: Enable noise immunity Date: Tue, 16 Feb 2021 18:41:31 +0100 Message-Id: <20210216174146.106639-2-jacopo+renesas@jmondi.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210216174146.106639-1-jacopo+renesas@jmondi.org> References: <20210216174146.106639-1-jacopo+renesas@jmondi.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Enable the noise immunity threshold at the end of the rdacm20 initialization routine. The rdcam20 camera module has been so far tested with a startup delay that allowed the embedded MCU to program the serializer. If the initialization routine is run before the MCU programs the serializer and the image sensor and their addresses gets changed by the rdacm20 driver it is required to manually enable the noise immunity threshold to make the communication on the control channel more reliable. Signed-off-by: Jacopo Mondi --- drivers/media/i2c/rdacm20.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/media/i2c/rdacm20.c b/drivers/media/i2c/rdacm20.c index 90eb73f0e6e9..f7fd5ae955d0 100644 --- a/drivers/media/i2c/rdacm20.c +++ b/drivers/media/i2c/rdacm20.c @@ -541,7 +541,13 @@ static int rdacm20_initialize(struct rdacm20_device *dev) dev_info(dev->dev, "Identified MAX9271 + OV10635 device\n"); - return 0; + /* + * Set reverse channel high threshold to increase noise immunity. + * + * This should be compensated by increasing the reverse channel + * amplitude on the remote deserializer side. + */ + return max9271_set_high_threshold(&dev->serializer, true); } static int rdacm20_probe(struct i2c_client *client) -- 2.30.0