From patchwork Sat Sep 12 00:55:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wang, Jiada" X-Patchwork-Id: 11771587 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 11E15618 for ; Sat, 12 Sep 2020 01:02:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F05D4221EF for ; Sat, 12 Sep 2020 01:02:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725857AbgILBCn (ORCPT ); Fri, 11 Sep 2020 21:02:43 -0400 Received: from esa2.mentor.iphmx.com ([68.232.141.98]:59507 "EHLO esa2.mentor.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725824AbgILBCm (ORCPT ); Fri, 11 Sep 2020 21:02:42 -0400 X-Greylist: delayed 434 seconds by postgrey-1.27 at vger.kernel.org; Fri, 11 Sep 2020 21:02:41 EDT IronPort-SDR: EfE4iC2+4LL0/B/o46YkugYCqq4P9Aiy+NH1MSArpXsRfj0+A6cgkzW+LP9SsIvVn8thcB0mVn V3O4uuu7finBoaRxU2Oe1XSJ5JATtKUUnK6nbQwD/R5x0ugtq80k83R+11q+rA+/qKzVUAMztT MaL3BuXZFNtHJOip0ltG5V3lCDHrx5M7P7q/pNbQ9H+Evymq9A5Tyodo0j58G2lzQ+J1C4F9sl LDhTU78heQ0YCVfYlWy4/6UHvOc422JfvcVz/KYeUqpOsFufiOV27pKSJPla6I+gKp0g3n0FHC 7/8= X-IronPort-AV: E=Sophos;i="5.76,418,1592899200"; d="scan'208";a="52850486" Received: from orw-gwy-01-in.mentorg.com ([192.94.38.165]) by esa2.mentor.iphmx.com with ESMTP; 11 Sep 2020 16:55:26 -0800 IronPort-SDR: zhk17P7uRb4t8+9rp61vPQuDeQ4c3kiOn7MRQ8sHjY/F0fOlTP7vsX0dTqLF6S+J4inoOsr/wX UvKKZmtrkl7dmQPy0twpcyv5wKju2KfcwMB1Fj23il6sY8qgA05rJJNMhrTdmsyXb4YrgFoiwQ 9R4Cc3gk4IwNhOrA9QCQzH3OH0+o6ueZoi+2CEwAL2jhIPNJAyrlZrTTnvB26olB1NqTFJKxLE 3eB35hrCWv4XQYDRhTfm2fb17C7Os7ZrfvARqs6o901OSD9+f45xO69w57o+75e/XGysP9qNSN 9SM= From: Jiada Wang To: , CC: , , , , , , Subject: [PATCH v4 1/1] Input: atmel_mxt_ts - implement I2C retries Date: Sat, 12 Sep 2020 09:55:21 +0900 Message-ID: <20200912005521.26319-1-jiada_wang@mentor.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org From: Nick Dyer Some maXTouch chips (eg mXT1386) 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 [gdavis: Forward port and fix conflicts.] Signed-off-by: George G. Davis [jiada: return exact errno when i2c_transfer & i2c_master_send fails rename "retry" to "retried" and keep its order in length set "ret" to correct errno before calling dev_err() remove reduntant conditional] Signed-off-by: Jiada Wang Reviewed-by: Dmitry Osipenko Tested-by: Dmitry Osipenko --- drivers/input/touchscreen/atmel_mxt_ts.c | 38 ++++++++++++++++-------- 1 file changed, 26 insertions(+), 12 deletions(-) diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c index a2189739e30f..bad3ac58503d 100644 --- a/drivers/input/touchscreen/atmel_mxt_ts.c +++ b/drivers/input/touchscreen/atmel_mxt_ts.c @@ -196,6 +196,7 @@ enum t100_type { #define MXT_CRC_TIMEOUT 1000 /* msec */ #define MXT_FW_RESET_TIME 3000 /* msec */ #define MXT_FW_CHG_TIMEOUT 300 /* msec */ +#define MXT_WAKEUP_TIME 25 /* msec */ /* Command to unlock bootloader */ #define MXT_UNLOCK_CMD_MSB 0xaa @@ -624,6 +625,7 @@ static int __mxt_read_reg(struct i2c_client *client, u16 reg, u16 len, void *val) { struct i2c_msg xfer[2]; + bool retried = false; u8 buf[2]; int ret; @@ -642,22 +644,28 @@ 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; +retry_read: + ret = i2c_transfer(client->adapter, xfer, ARRAY_SIZE(xfer)); + if (ret != ARRAY_SIZE(xfer)) { + if (!retried) { + dev_dbg(&client->dev, "i2c retry\n"); + msleep(MXT_WAKEUP_TIME); + retried = true; + goto retry_read; + } + ret = ret < 0 ? ret : -EIO; dev_err(&client->dev, "%s: i2c transfer failed (%d)\n", __func__, ret); + return ret; } - return ret; + return 0; } static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len, const void *val) { + bool retried = false; u8 *buf; size_t count; int ret; @@ -671,14 +679,20 @@ 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) - ret = -EIO; + if (ret != count) { + if (!retried) { + dev_dbg(&client->dev, "i2c retry\n"); + msleep(MXT_WAKEUP_TIME); + retried = true; + goto retry_write; + } + ret = ret < 0 ? ret : -EIO; dev_err(&client->dev, "%s: i2c send failed (%d)\n", __func__, ret); + } else { + ret = 0; } kfree(buf);