From patchwork Fri Feb 22 17:58:12 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nick Dyer X-Patchwork-Id: 2177021 Return-Path: X-Original-To: patchwork-linux-input@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 87E313FCFC for ; Fri, 22 Feb 2013 18:11:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932262Ab3BVSJZ (ORCPT ); Fri, 22 Feb 2013 13:09:25 -0500 Received: from [89.21.227.133] ([89.21.227.133]:10930 "EHLO mail.kdh.itdev.co.uk" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1759097Ab3BVSIh (ORCPT ); Fri, 22 Feb 2013 13:08:37 -0500 Received: from juno.kdh.itdev.co.uk (andromeda.kdh.itdev.co.uk [192.168.1.38]) by mail.kdh.itdev.co.uk (Postfix) with ESMTP id 489042421A; Fri, 22 Feb 2013 17:59:14 +0000 (GMT) From: Nick Dyer To: Dmitry Torokhov , Daniel Kurtz , Henrik Rydberg , Joonyoung Shim , Alan.Bowens@atmel.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, pmeerw@pmeerw.net, bleung@chromium.org, olofj@chromium.org Cc: Nick Dyer Subject: [PATCH 25/40] Input: atmel_mxt_ts - implement I2C retries Date: Fri, 22 Feb 2013 17:58:12 +0000 Message-Id: <1361555907-19840-26-git-send-email-nick.dyer@itdev.co.uk> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1361555907-19840-1-git-send-email-nick.dyer@itdev.co.uk> References: <1361555907-19840-1-git-send-email-nick.dyer@itdev.co.uk> Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Some maXTouch chips will not respond on the first I2C request when they are in a sleep state. It must be retried after a delay for the chip to wake up. Signed-off-by: Nick Dyer --- drivers/input/touchscreen/atmel_mxt_ts.c | 39 +++++++++++++++++++++--------- 1 file changed, 27 insertions(+), 12 deletions(-) diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c index 6ab7ef6..b0dcae4 100644 --- a/drivers/input/touchscreen/atmel_mxt_ts.c +++ b/drivers/input/touchscreen/atmel_mxt_ts.c @@ -193,6 +193,7 @@ struct t9_range { #define MXT_RESET_TIME 200 /* msec */ #define MXT_RESET_NOCHGREAD 400 /* msec */ #define MXT_FWRESET_TIME 1000 /* msec */ +#define MXT_WAKEUP_TIME 25 /* msec */ /* Command to unlock bootloader */ #define MXT_UNLOCK_CMD_MSB 0xaa @@ -503,6 +504,7 @@ static int __mxt_read_reg(struct i2c_client *client, struct i2c_msg xfer[2]; u8 buf[2]; int ret; + bool retry = false; buf[0] = reg & 0xff; buf[1] = (reg >> 8) & 0xff; @@ -519,17 +521,22 @@ static int __mxt_read_reg(struct i2c_client *client, xfer[1].len = len; xfer[1].buf = val; - ret = i2c_transfer(client->adapter, xfer, 2); - if (ret == 2) { - ret = 0; - } else { - if (ret >= 0) - ret = -EIO; - dev_err(&client->dev, "%s: i2c transfer failed (%d)\n", - __func__, ret); +retry_read: + ret = i2c_transfer(client->adapter, xfer, ARRAY_SIZE(xfer)); + if (ret != ARRAY_SIZE(xfer)) { + if (!retry) { + dev_dbg(&client->dev, "%s: i2c retry\n", __func__); + msleep(MXT_WAKEUP_TIME); + retry = true; + goto retry_read; + } else { + dev_err(&client->dev, "%s: i2c transfer failed (%d)\n", + __func__, ret); + return -EIO; + } } - return ret; + return 0; } static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len, @@ -538,6 +545,7 @@ static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len, u8 *buf; size_t count; int ret; + bool retry = false; count = len + 2; buf = kmalloc(count, GFP_KERNEL); @@ -548,14 +556,21 @@ static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len, buf[1] = (reg >> 8) & 0xff; memcpy(&buf[2], val, len); +retry_write: ret = i2c_master_send(client, buf, count); if (ret == count) { ret = 0; } else { - if (ret >= 0) + if (!retry) { + dev_dbg(&client->dev, "%s: i2c retry\n", __func__); + msleep(MXT_WAKEUP_TIME); + retry = true; + goto retry_write; + } else { + dev_err(&client->dev, "%s: i2c send failed (%d)\n", + __func__, ret); ret = -EIO; - dev_err(&client->dev, "%s: i2c send failed (%d)\n", - __func__, ret); + } } kfree(buf);