[PATCH v4 5/6] drivers/i2c: Add bus recovery for FSI algorithm

Path	csiph.com!aioe.org!bofh.it!news.nic.it!robomod
From	Eddie James <eajames@linux.vnet.ibm.com>
Newsgroups	linux.kernel
Subject	[PATCH v4 5/6] drivers/i2c: Add bus recovery for FSI algorithm
Date	Mon, 17 Jul 2017 16:40:02 +0200
Message-ID	<u4flM-6ht-7@gated-at.bofh.it> (permalink)
References	<u4flM-6ht-9@gated-at.bofh.it>
X-Original-To	linux-kernel@vger.kernel.org
X-Mailer	git-send-email 1.8.3.1
X-Tm-As-Gconf	00
X-Cbid	17071714-0020-0000-0000-00000C6366F3
X-Ibm-Spammodules-Versions	BY=3.00007378; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00888884; UDB=6.00443946; IPR=6.00669056; BA=6.00005475; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016250; XFM=3.00000015; UTC=2017-07-17 14:36:18
X-Ibm-Av-Detection	SAVI=unused REMOTE=unused XFE=unused
X-Cbparentid	17071714-0021-0000-0000-00005D4A91FA
X-Proofpoint-Virus-Version	vendor=fsecure engine=2.50.10432:,, definitions=2017-07-17_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-1707170231
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	105
Organization	linux.* mail to news gateway
X-Original-Cc	linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, wsa@the-dreams.de, robh+dt@kernel.org, gregkh@linuxfoundation.org, jk@ozlabs.org, joel@jms.id.au, andrew@aj.id.au, eajames@linux.vnet.ibm.com, cbostic@linux.vnet.ibm.com, "Edward A. James" <eajames@us.ibm.com>
X-Original-Date	Mon, 17 Jul 2017 09:35:56 -0500
X-Original-Message-ID	<1500302157-14670-6-git-send-email-eajames@linux.vnet.ibm.com>
X-Original-References	<1500302157-14670-1-git-send-email-eajames@linux.vnet.ibm.com>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	csiph.com linux.kernel:1689110

Show key headers only | View raw

From: "Edward A. James" <eajames@us.ibm.com>

Bus recovery should reset the engine and force clock the bus 9 times
to recover most situations.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
---
 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 1c7fcae..2739535 100644
--- a/drivers/i2c/busses/i2c-fsi.c
+++ b/drivers/i2c/busses/i2c-fsi.c
@@ -468,6 +468,80 @@ static u32 fsi_i2c_functionality(struct i2c_adapter *adap)
 	return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_10BIT_ADDR;
 }
 
+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,
@@ -507,6 +581,7 @@ 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

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[PATCH v4 5/6] drivers/i2c: Add bus recovery for FSI algorithm Eddie James <eajames@linux.vnet.ibm.com> - 2017-07-17 16:40 +0200

csiph-web