From patchwork Mon Mar 15 13:14:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacopo Mondi X-Patchwork-Id: 402119 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=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 26B93C433E9 for ; Mon, 15 Mar 2021 13:16:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F321564F09 for ; Mon, 15 Mar 2021 13:16:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230036AbhCONP1 (ORCPT ); Mon, 15 Mar 2021 09:15:27 -0400 Received: from relay9-d.mail.gandi.net ([217.70.183.199]:53705 "EHLO relay9-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230081AbhCONO6 (ORCPT ); Mon, 15 Mar 2021 09:14:58 -0400 X-Originating-IP: 79.22.58.175 Received: from uno.homenet.telecomitalia.it (host-79-22-58-175.retail.telecomitalia.it [79.22.58.175]) (Authenticated sender: jacopo@jmondi.org) by relay9-d.mail.gandi.net (Postfix) with ESMTPSA id 2AABBFF815; Mon, 15 Mar 2021 13:14:53 +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 v2 02/18] media: i2c: rdacm20: Enable noise immunity Date: Mon, 15 Mar 2021 14:14:56 +0100 Message-Id: <20210315131512.133720-3-jacopo+renesas@jmondi.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210315131512.133720-1-jacopo+renesas@jmondi.org> References: <20210315131512.133720-1-jacopo+renesas@jmondi.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Enable the noise immunity threshold at the end of the rdacm20 initialization routine. The rdacm20 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. Reviewed-by: Kieran Bingham 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)