Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751769AbdGZRNt (ORCPT ); Wed, 26 Jul 2017 13:13:49 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54210 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751389AbdGZRNn (ORCPT ); Wed, 26 Jul 2017 13:13:43 -0400 From: Eddie James To: linux-kernel@vger.kernel.org Cc: linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, wsa@the-dreams.de, robh+dt@kernel.org, jk@ozlabs.org, joel@jms.id.au, andrew@aj.id.au, cbostic@linux.vnet.ibm.com, eajames@linux.vnet.ibm.com, "Edward A. James" Subject: [PATCH v5 5/6] drivers/i2c: Add bus recovery for FSI algorithm Date: Wed, 26 Jul 2017 12:13:17 -0500 X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1501089198-10356-1-git-send-email-eajames@linux.vnet.ibm.com> References: <1501089198-10356-1-git-send-email-eajames@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17072617-0028-0000-0000-00000817B1B2 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007430; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00893242; UDB=6.00446544; IPR=6.00673406; BA=6.00005492; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016390; XFM=3.00000015; UTC=2017-07-26 17:13:41 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17072617-0029-0000-0000-000036DBBE2D Message-Id: <1501089198-10356-6-git-send-email-eajames@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-07-26_07:,, 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-1707260249 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2670 Lines: 105 From: "Edward A. James" Bus recovery should reset the engine and force clock the bus 9 times to recover most situations. Signed-off-by: Edward A. James --- drivers/i2c/busses/i2c-fsi.c | 75 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c index 3a1f317..1af9c01 100644 --- a/drivers/i2c/busses/i2c-fsi.c +++ b/drivers/i2c/busses/i2c-fsi.c @@ -469,6 +469,80 @@ static u32 fsi_i2c_functionality(struct i2c_adapter *adap) | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA; } +static int fsi_i2c_low_level_recover_bus(struct fsi_i2c_master *i2c) +{ + int i, rc; + u32 mode, dummy = 0; + + rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode); + if (rc) + return rc; + + mode |= I2C_MODE_DIAG; + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode); + if (rc) + return rc; + + for (i = 0; i < 9; ++i) { + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy); + if (rc) + return rc; + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy); + if (rc) + return rc; + } + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy); + if (rc) + return rc; + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SDA, &dummy); + if (rc) + return rc; + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy); + if (rc) + return rc; + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SDA, &dummy); + if (rc) + return rc; + + mode &= ~I2C_MODE_DIAG; + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode); + + return rc; +} + +static int fsi_i2c_recover_bus(struct i2c_adapter *adap) +{ + int rc; + u32 dummy = 0; + struct fsi_i2c_port *port = adap->algo_data; + struct fsi_i2c_master *i2c = port->master; + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy); + if (rc) + return rc; + + rc = fsi_i2c_dev_init(i2c); + if (rc) + return rc; + + rc = fsi_i2c_low_level_recover_bus(i2c); + if (rc) + return rc; + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy); + + return rc; +} + +static struct i2c_bus_recovery_info fsi_i2c_bus_recovery_info = { + .recover_bus = fsi_i2c_recover_bus, +}; + static const struct i2c_algorithm fsi_i2c_algorithm = { .master_xfer = fsi_i2c_xfer, .functionality = fsi_i2c_functionality, @@ -512,6 +586,7 @@ static int fsi_i2c_probe(struct device *dev) port->adapter.dev.of_node = np; port->adapter.dev.parent = dev; port->adapter.algo = &fsi_i2c_algorithm; + port->adapter.bus_recovery_info = &fsi_i2c_bus_recovery_info; port->adapter.algo_data = port; snprintf(port->adapter.name, sizeof(port->adapter.name), -- 1.8.3.1