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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 1A8F1C76564 for ; Thu, 27 Feb 2020 14:38:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E179324656 for ; Thu, 27 Feb 2020 14:38:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582814286; bh=NTq86b0DCPvXQOu5B4YCHjoybaZyE1rhW4Q21+e191c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GExCc1kTkqIfZzTD67wPvTrvM9YRNXK3urvhJzMD33fMTZqZBDHCJ+cXFgXH1m8Yz 1F1HMpiuj9Rg3dfI/GkvydY8b9fTRu9Vqt61Vz2gkScy5DYPrN3hJWYoOPf3/HKlna sQIQcXPXKaxCvvRecRwwdnL8UgoQ5y764+Pg2dgk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387967AbgB0OiE (ORCPT ); Thu, 27 Feb 2020 09:38:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:57478 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732207AbgB0N4t (ORCPT ); Thu, 27 Feb 2020 08:56:49 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7128C20578; Thu, 27 Feb 2020 13:56:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582811808; bh=NTq86b0DCPvXQOu5B4YCHjoybaZyE1rhW4Q21+e191c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lCfR+2HdJMr0fZRf3+hNECqTsHbK/OET5IxqAI511qyqj67mmJffSEfITa+ye83Mq or8ecu0Sp7v9itSt+8+ApIQNn/sk8tr93VXuhqfx12rWHynYCj8FOOI2FVZQn1fG1M maL0vWzGioOZ9k2B9LTMG3L5n67PurqwQbE1pSn4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Philipp Zabel , Marco Felsch , Andy Shevchenko , Dmitry Torokhov , Sasha Levin Subject: [PATCH 4.14 108/237] Input: edt-ft5x06 - work around first register access error Date: Thu, 27 Feb 2020 14:35:22 +0100 Message-Id: <20200227132304.849850280@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200227132255.285644406@linuxfoundation.org> References: <20200227132255.285644406@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Philipp Zabel [ Upstream commit e112324cc0422c046f1cf54c56f333d34fa20885 ] The EP0700MLP1 returns bogus data on the first register read access (reading the threshold parameter from register 0x00): edt_ft5x06 2-0038: crc error: 0xfc expected, got 0x40 It ignores writes until then. This patch adds a dummy read after which the number of sensors and parameter read/writes work correctly. Signed-off-by: Philipp Zabel Signed-off-by: Marco Felsch Tested-by: Andy Shevchenko Reviewed-by: Andy Shevchenko Signed-off-by: Dmitry Torokhov Signed-off-by: Sasha Levin --- drivers/input/touchscreen/edt-ft5x06.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c index 5bf63f76dddac..4eff5b44640cf 100644 --- a/drivers/input/touchscreen/edt-ft5x06.c +++ b/drivers/input/touchscreen/edt-ft5x06.c @@ -888,6 +888,7 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client, { const struct edt_i2c_chip_data *chip_data; struct edt_ft5x06_ts_data *tsdata; + u8 buf[2] = { 0xfc, 0x00 }; struct input_dev *input; unsigned long irq_flags; int error; @@ -957,6 +958,12 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client, return error; } + /* + * Dummy read access. EP0700MLP1 returns bogus data on the first + * register read access and ignores writes. + */ + edt_ft5x06_ts_readwrite(tsdata->client, 2, buf, 2, buf); + edt_ft5x06_ts_set_regs(tsdata); edt_ft5x06_ts_get_defaults(&client->dev, tsdata); edt_ft5x06_ts_get_parameters(tsdata); -- 2.20.1