From patchwork Fri May 12 12:36:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacopo Mondi X-Patchwork-Id: 9724043 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7DFF1600CB for ; Fri, 12 May 2017 12:37:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 63789223C7 for ; Fri, 12 May 2017 12:37:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5507E283FD; Fri, 12 May 2017 12:37:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AFF4F28811 for ; Fri, 12 May 2017 12:37:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751890AbdELMhI (ORCPT ); Fri, 12 May 2017 08:37:08 -0400 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:37020 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751272AbdELMhI (ORCPT ); Fri, 12 May 2017 08:37:08 -0400 Received: from w540.lan (unknown [IPv6:2001:b07:6442:1ac4:101:582b:9c58:7e82]) (Authenticated sender: jacopo@jmondi.org) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id 7A1AB1720E9; Fri, 12 May 2017 14:37:04 +0200 (CEST) From: Jacopo Mondi To: laurent.pinchart@ideasonboard.com, mchehab@kernel.org, hans.verkuil@cisco.com, sakari.ailus@linux.intel.com, sre@kernel.org, magnus.damm@gmail.com, wsa+renesas@sang-engineering.com Cc: linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org Subject: [PATCH v3] media: i2c: ov772x: Force use of SCCB protocol Date: Fri, 12 May 2017 14:36:59 +0200 Message-Id: <1494592619-23231-1-git-send-email-jacopo@jmondi.org> X-Mailer: git-send-email 2.7.4 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Commit e78902976150 ("i2c: sh_mobile: don't send a stop condition by default inside transfers") makes the i2c_sh_mobile I2C-adapter emit a stop/start sequence between messages in a single transfer only when explicitly requested with I2C_M_STOP. This breaks the ov772x driver in the SH4 Migo-R board as the Omnivision sensor uses the I2C-like SCCB protocol that doesn't support repeated starts: i2c-sh_mobile i2c-sh_mobile.0: Transfer request timed out ov772x 0-0021: Product ID error 92:92 Fix it by marking the client as SCCB, forcing the emission of a stop/start sequence between all messages. As I2C_M_STOP requires the I2C adapter to support protocol mangling, ensure that the I2C_FUNC_PROTOCOL_MANGLING functionality is available. Tested on SH4 Migo-R board, with OV772x now successfully probing soc-camera-pdrv soc-camera-pdrv.0: Probing soc-camera-pdrv.0 ov772x 0-0021: ov7725 Product ID 77:21 Manufacturer ID 7f:a2 Signed-off-by: Jacopo Mondi Suggested-by: Laurent Pinchart Acked-by: Wolfram Sang Reviewed-by: Laurent Pinchart --- v1 -> v2: - change commit message to describe what this fix is for first. v2 -> v3: - add to commit message that patch checks for I2C_FUNC_PROTOCOL_MANGLING support drivers/media/i2c/soc_camera/ov772x.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) -- 2.7.4 diff --git a/drivers/media/i2c/soc_camera/ov772x.c b/drivers/media/i2c/soc_camera/ov772x.c index 985a367..351abec 100644 --- a/drivers/media/i2c/soc_camera/ov772x.c +++ b/drivers/media/i2c/soc_camera/ov772x.c @@ -1062,11 +1062,13 @@ static int ov772x_probe(struct i2c_client *client, return -EINVAL; } - if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) { + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_PROTOCOL_MANGLING)) { dev_err(&adapter->dev, - "I2C-Adapter doesn't support I2C_FUNC_SMBUS_BYTE_DATA\n"); + "I2C-Adapter doesn't support SMBUS_BYTE_DATA or PROTOCOL_MANGLING\n"); return -EIO; } + client->flags |= I2C_CLIENT_SCCB; priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL); if (!priv)