X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=drivers%2Fi2c%2Fppc4xx_i2c.c;h=df8888550bb0e2010db25362ca9695b4ac7a293e;hb=007025183626f8ba492ba29bdb88159bb7a4d53f;hp=c924874b599d20de6aaee77483f07721e5412386;hpb=880540decfb855e96bc14ac84ac7784669e4b382;p=oweals%2Fu-boot.git

diff --git a/drivers/i2c/ppc4xx_i2c.c b/drivers/i2c/ppc4xx_i2c.c
index c924874b59..df8888550b 100644
--- a/drivers/i2c/ppc4xx_i2c.c
+++ b/drivers/i2c/ppc4xx_i2c.c
@@ -7,23 +7,7 @@
  * (C) Copyright 2001
  * Bill Hunter,  Wave 7 Optics, williamhunter@mediaone.net
  *
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
+ * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>
@@ -174,8 +158,7 @@ static void ppc4xx_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
  *
  * Typical case is a Write of an addr followd by a Read. The
  * IBM FAQ does not cover this. On the last byte of the write
- * we don't set the creg CHT bit, and on the first bytes of the
- * read we set the RPST bit.
+ * we don't set the creg CHT bit but the RPST bit.
  *
  * It does not support address only transfers, there must be
  * a data part. If you want to write the address yourself, put
@@ -263,6 +246,10 @@ static int _i2c_transfer(struct i2c_adapter *adap,
 		if ((!cmd_type && (ptr == addr)) || ((tran + bc) != cnt))
 			creg |= IIC_CNTL_CHT;
 
+		/* last part of address, prepare for repeated start on read */
+		if (cmd_type && (ptr == addr) && ((tran + bc) == cnt))
+			creg |= IIC_CNTL_RPST;
+
 		if (reading) {
 			creg |= IIC_CNTL_READ;
 		} else {
@@ -302,6 +289,27 @@ static int _i2c_transfer(struct i2c_adapter *adap,
 			/* Transfer aborted? */
 			if (status & IIC_EXTSTS_XFRA)
 				result = IIC_NOK_XFRA;
+			/* Is bus free?
+			 * If error happened during combined xfer
+			 * IIC interface is usually stuck in some strange
+			 * state without a valid stop condition.
+			 * Brute, but working: generate stop, then soft reset.
+			 */
+			if ((status & IIC_EXTSTS_BCS_MASK)
+			    != IIC_EXTSTS_BCS_FREE){
+				u8 mdcntl = in_8(&i2c->mdcntl);
+
+				/* Generate valid stop condition */
+				out_8(&i2c->xtcntlss, IIC_XTCNTLSS_SRST);
+				out_8(&i2c->directcntl, IIC_DIRCNTL_SCC);
+				udelay(10);
+				out_8(&i2c->directcntl,
+				      IIC_DIRCNTL_SCC | IIC_DIRCNTL_SDAC);
+				out_8(&i2c->xtcntlss, 0);
+
+				ppc4xx_i2c_init(adap, (mdcntl & IIC_MDCNTL_FSM)
+						? 400000 : 100000, 0);
+			}
 		} else if ( status & IIC_STS_PT) {
 			result = IIC_NOK_TOUT;
 		}
@@ -330,8 +338,6 @@ static int _i2c_transfer(struct i2c_adapter *adap,
 			cnt = data_len;
 			tran = 0;
 			reading = cmd_type;
-			if (reading)
-				creg = IIC_CNTL_RPST;
 		}
 	}
 	return result;