From patchwork Mon Apr 12 09:34:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacopo Mondi X-Patchwork-Id: 12197387 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 6F6D9C43460 for ; Mon, 12 Apr 2021 09:37:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4BD0A61247 for ; Mon, 12 Apr 2021 09:37:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241271AbhDLJhg (ORCPT ); Mon, 12 Apr 2021 05:37:36 -0400 Received: from relay12.mail.gandi.net ([217.70.178.232]:48177 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240669AbhDLJez (ORCPT ); Mon, 12 Apr 2021 05:34:55 -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 B6893200013; Mon, 12 Apr 2021 09:34:32 +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 07/17] media: i2c: max9271: Introduce wake_up() function Date: Mon, 12 Apr 2021 11:34:41 +0200 Message-Id: <20210412093451.14198-8-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 MAX9271 chip manual prescribes a delay of 5 milliseconds after the chip exits from low power state. Add a new function to the max9271 library driver that wakes up the chip with a dummy i2c transaction and implements the correct delay of 5 milliseconds after the chip exits from low power state. Use the newly introduced function in the rdacm20 and rdacm21 camera drivers. The former was not respecting the required delay while the latter was waiting for a too-short timeout. Reviewed-by: Kieran Bingham Reviewed-by: Laurent Pinchart Signed-off-by: Jacopo Mondi --- drivers/media/i2c/max9271.c | 12 ++++++++++++ drivers/media/i2c/max9271.h | 9 +++++++++ drivers/media/i2c/rdacm20.c | 4 +--- drivers/media/i2c/rdacm21.c | 5 +---- 4 files changed, 23 insertions(+), 7 deletions(-) diff --git a/drivers/media/i2c/max9271.c b/drivers/media/i2c/max9271.c index 2c7dc7fb9846..ff86c8c4ea61 100644 --- a/drivers/media/i2c/max9271.c +++ b/drivers/media/i2c/max9271.c @@ -80,6 +80,18 @@ static int max9271_pclk_detect(struct max9271_device *dev) return -EIO; } +void max9271_wake_up(struct max9271_device *dev) +{ + /* + * Use the chip default address as this function has to be called + * before any other one. + */ + dev->client->addr = MAX9271_DEFAULT_ADDR; + i2c_smbus_read_byte(dev->client); + usleep_range(5000, 8000); +} +EXPORT_SYMBOL_GPL(max9271_wake_up); + int max9271_set_serial_link(struct max9271_device *dev, bool enable) { int ret; diff --git a/drivers/media/i2c/max9271.h b/drivers/media/i2c/max9271.h index d78fb21441e9..dc5e4e70ba6f 100644 --- a/drivers/media/i2c/max9271.h +++ b/drivers/media/i2c/max9271.h @@ -85,6 +85,15 @@ struct max9271_device { struct i2c_client *client; }; +/** + * max9271_wake_up() - Wake up the serializer by issuing an i2c transaction + * @dev: The max9271 device + * + * This function shall be called before any other interaction with the + * serializer. + */ +void max9271_wake_up(struct max9271_device *dev); + /** * max9271_set_serial_link() - Enable/disable serial link * @dev: The max9271 device diff --git a/drivers/media/i2c/rdacm20.c b/drivers/media/i2c/rdacm20.c index 90eb73f0e6e9..c1a717153303 100644 --- a/drivers/media/i2c/rdacm20.c +++ b/drivers/media/i2c/rdacm20.c @@ -455,9 +455,7 @@ static int rdacm20_initialize(struct rdacm20_device *dev) unsigned int retry = 3; int ret; - /* Verify communication with the MAX9271: ping to wakeup. */ - dev->serializer->client->addr = MAX9271_DEFAULT_ADDR; - i2c_smbus_read_byte(dev->serializer->client); + max9271_wake_up(dev->serializer); /* Serial link disabled during config as it needs a valid pixel clock. */ ret = max9271_set_serial_link(dev->serializer, false); diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c index 179d107f494c..553e3f03752b 100644 --- a/drivers/media/i2c/rdacm21.c +++ b/drivers/media/i2c/rdacm21.c @@ -450,10 +450,7 @@ static int rdacm21_initialize(struct rdacm21_device *dev) { int ret; - /* Verify communication with the MAX9271: ping to wakeup. */ - dev->serializer.client->addr = MAX9271_DEFAULT_ADDR; - i2c_smbus_read_byte(dev->serializer.client); - usleep_range(3000, 5000); + max9271_wake_up(&dev->serializer); /* Enable reverse channel and disable the serial link. */ ret = max9271_set_serial_link(&dev->serializer, false);