From patchwork Tue Aug 1 00:49:04 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eddie James X-Patchwork-Id: 796023 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xLyR60skMz9tWk for ; Tue, 1 Aug 2017 10:50:26 +1000 (AEST) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3xLyR55qlYzDsSk for ; Tue, 1 Aug 2017 10:50:25 +1000 (AEST) X-Original-To: openbmc@lists.ozlabs.org Delivered-To: openbmc@lists.ozlabs.org Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3xLyPz1mzgzDsSy for ; Tue, 1 Aug 2017 10:49:27 +1000 (AEST) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v710mmNx028146 for ; Mon, 31 Jul 2017 20:49:24 -0400 Received: from e17.ny.us.ibm.com (e17.ny.us.ibm.com [129.33.205.207]) by mx0b-001b2d01.pphosted.com with ESMTP id 2c2bqug4pr-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 31 Jul 2017 20:49:23 -0400 Received: from localhost by e17.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 31 Jul 2017 20:49:21 -0400 Received: from b01ledav004.gho.pok.ibm.com (b01ledav004.gho.pok.ibm.com [9.57.199.109]) by b01cxnp22033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v710nLq123003386; Tue, 1 Aug 2017 00:49:21 GMT Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8A4F0112034; Mon, 31 Jul 2017 20:49:14 -0400 (EDT) Received: from oc3016140333.ibm.com (unknown [9.85.136.69]) by b01ledav004.gho.pok.ibm.com (Postfix) with ESMTP id 343CE112040; Mon, 31 Jul 2017 20:49:14 -0400 (EDT) From: Eddie James To: openbmc@lists.ozlabs.org Subject: [PATCH linux dev-4.12 4/6] drivers/i2c: Add I2C master locking to FSI algorithm Date: Mon, 31 Jul 2017 19:49:04 -0500 X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1501548546-21096-1-git-send-email-eajames@linux.vnet.ibm.com> References: <1501548546-21096-1-git-send-email-eajames@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17080100-0040-0000-0000-00000388A183 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007462; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00895760; UDB=6.00448039; IPR=6.00675947; BA=6.00005503; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016472; XFM=3.00000015; UTC=2017-08-01 00:49:23 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17080100-0041-0000-0000-0000077CCABA Message-Id: <1501548546-21096-5-git-send-email-eajames@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-07-31_11:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1706020000 definitions=main-1708010009 X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Edward A. James" Errors-To: openbmc-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "openbmc" From: "Edward A. James" Since there are many ports per master, each with it's own adapter and chardev, we need some locking to prevent transfers from changing the\ master state while other transfers are in progress. Signed-off-by: Edward A. James --- drivers/i2c/busses/i2c-fsi.c | 43 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 39 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c index d37f2c8..3a1f317 100644 --- a/drivers/i2c/busses/i2c-fsi.c +++ b/drivers/i2c/busses/i2c-fsi.c @@ -19,6 +19,8 @@ #include #include #include +#include +#include #define FSI_ENGID_I2C 0x7 @@ -135,6 +137,8 @@ struct fsi_i2c_master { struct fsi_device *fsi; u8 fifo_size; struct list_head ports; + wait_queue_head_t wait; + struct semaphore lock; }; struct fsi_i2c_port { @@ -168,6 +172,29 @@ static int fsi_i2c_write_reg(struct fsi_device *fsi, unsigned int reg, return fsi_device_write(fsi, reg, &data_be, sizeof(data_be)); } +static int fsi_i2c_lock_master(struct fsi_i2c_master *i2c, int timeout) +{ + int rc; + + rc = down_trylock(&i2c->lock); + if (!rc) + return 0; + + rc = wait_event_interruptible_timeout(i2c->wait, + !down_trylock(&i2c->lock), + timeout); + if (rc > 0) + return 0; + + return -EBUSY; +} + +static void fsi_i2c_unlock_master(struct fsi_i2c_master *i2c) +{ + up(&i2c->lock); + wake_up(&i2c->wait); +} + static int fsi_i2c_dev_init(struct fsi_i2c_master *i2c) { int rc; @@ -409,25 +436,31 @@ static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, struct fsi_i2c_port *port = adap->algo_data; struct i2c_msg *msg; - rc = fsi_i2c_set_port(port); + rc = fsi_i2c_lock_master(port->master, adap->timeout); if (rc) return rc; + rc = fsi_i2c_set_port(port); + if (rc) + goto unlock; + for (i = 0; i < num; ++i) { msg = msgs + i; start_time = jiffies; rc = fsi_i2c_start(port, msg, i == num - 1); if (rc) - return rc; + goto unlock; rc = fsi_i2c_wait(port, msg, adap->timeout - (jiffies - start_time)); if (rc) - return rc; + goto unlock; } - return 0; +unlock: + fsi_i2c_unlock_master(port->master); + return rc; } static u32 fsi_i2c_functionality(struct i2c_adapter *adap) @@ -453,6 +486,8 @@ static int fsi_i2c_probe(struct device *dev) if (!i2c) return -ENOMEM; + init_waitqueue_head(&i2c->wait); + sema_init(&i2c->lock, 1); i2c->fsi = to_fsi_dev(dev); INIT_LIST_HEAD(&i2c->ports);