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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 2A725C433E6 for ; Mon, 22 Feb 2021 01:28:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC45B64EC8 for ; Mon, 22 Feb 2021 01:28:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230169AbhBVB2k (ORCPT ); Sun, 21 Feb 2021 20:28:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229889AbhBVB2e (ORCPT ); Sun, 21 Feb 2021 20:28:34 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A87ECC061574; Sun, 21 Feb 2021 17:27:53 -0800 (PST) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 0608A517; Mon, 22 Feb 2021 02:27:51 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1613957272; bh=DvouH4As8+RR+VV2xQsF4c0eG8ofBC2VwV6/+LxrUTk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=szb1MosGWvFTvscWxXgqQr0mIBnedrBb/TsUgTnJioe28FKhQNg0DGwA3VHZuQXEX pU7DViEkW0xWYy/iYn8CJzGa2ohJvjz+1g8w2DpsZBxvow1/nVFlh+4pFMOBx8YUqY gmfOZ3QUDp9P7wJhjcJGEZ+Pft4mS7pC0wMdTODo= Date: Mon, 22 Feb 2021 03:27:25 +0200 From: Laurent Pinchart To: Jacopo Mondi Cc: kieran.bingham+renesas@ideasonboard.com, niklas.soderlund+renesas@ragnatech.se, geert@linux-m68k.org, Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 09/16] media: i2c: rdacm21: Re-work OV10640 initialization Message-ID: References: <20210216174146.106639-1-jacopo+renesas@jmondi.org> <20210216174146.106639-10-jacopo+renesas@jmondi.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210216174146.106639-10-jacopo+renesas@jmondi.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jacopo, Thank you for the patch. On Tue, Feb 16, 2021 at 06:41:39PM +0100, Jacopo Mondi wrote: > The OV10640 image sensor reset and powerdown on signals are controlled s/ on// > by the embedded OV490 ISP. The current reset procedure does not respect > the 1 millisecond power-up delay and releases the reset signal before > the powerdown one. > > Fix the OV10640 power up sequence by releasing the powerdown signal, > waiting the mandatory 1 millisecond power up delay and then releasing > the reset signal. The reset delay is not characterized in the chip > manual if not as "255 XVCLK + initialization". Wait for at least 3 > milliseconds to guarantee the SCCB bus is available. > > This commit fixes a sporadic start-up error triggered by a failure to > read the OV10640 chip ID: > rdacm21 8-0054: OV10640 ID mismatch: (0x01) > > Signed-off-by: Jacopo Mondi > --- > drivers/media/i2c/rdacm21.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c > index b22a2ca5340b..c420a6b96879 100644 > --- a/drivers/media/i2c/rdacm21.c > +++ b/drivers/media/i2c/rdacm21.c > @@ -333,13 +333,15 @@ static int ov10640_initialize(struct rdacm21_device *dev) > { > u8 val; > > - /* Power-up OV10640 by setting RESETB and PWDNB pins high. */ > + /* Power-up OV10640 by setting PWDNB and RESETB pins high. */ > ov490_write_reg(dev, OV490_GPIO_SEL0, OV490_GPIO0); > ov490_write_reg(dev, OV490_GPIO_SEL1, OV490_SPWDN0); > ov490_write_reg(dev, OV490_GPIO_DIRECTION0, OV490_GPIO0); > ov490_write_reg(dev, OV490_GPIO_DIRECTION1, OV490_SPWDN0); > - ov490_write_reg(dev, OV490_GPIO_OUTPUT_VALUE0, OV490_GPIO0); > + > ov490_write_reg(dev, OV490_GPIO_OUTPUT_VALUE0, OV490_SPWDN0); Shouldn't this be OV490_GPIO_OUTPUT_VALUE1 ? > + usleep_range(1500, 3000); > + ov490_write_reg(dev, OV490_GPIO_OUTPUT_VALUE0, OV490_GPIO0); I'm a bit puzzled by why this patch would improve the ID read issue, given that it sets GPIO0 to 1, then sets GPIO0 to 1, compared to previously setting GPIO0 to 1 following by setting GPIO0 to 1 :-) Maybe it's the additional delay ? In any case, it would probably be a good idea to perform additional tests after fixing this. > usleep_range(3000, 5000); > > /* Read OV10640 ID to test communications. */ -- Regards, Laurent Pinchart