From: Wolfram Sang <w.sang@pengutronix.de>
Date: Sat, 28 Mar 2009 20:34:45 +0000 (+0100)
Subject: i2c-algo-pca: Rework waiting for a free bus
X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=8e99ada8deaa9033600cd2c7d0a9366b0e99ab68;p=linux-2.6-omap-h63xx.git

i2c-algo-pca: Rework waiting for a free bus

Waiting for a free bus now accepts the timeout value in jiffies and does
proper checking using time_before.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
---

diff --git a/arch/sh/boards/board-sh7785lcr.c b/arch/sh/boards/board-sh7785lcr.c
index 94c0296bc35..6f94f17adc4 100644
--- a/arch/sh/boards/board-sh7785lcr.c
+++ b/arch/sh/boards/board-sh7785lcr.c
@@ -229,7 +229,7 @@ static struct resource i2c_resources[] = {
 static struct i2c_pca9564_pf_platform_data i2c_platform_data = {
 	.gpio			= 0,
 	.i2c_clock_speed	= I2C_PCA_CON_330kHz,
-	.timeout		= 100,
+	.timeout		= HZ,
 };
 
 static struct platform_device i2c_device = {
diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
index a8e51bd1a4f..9e134fad7bd 100644
--- a/drivers/i2c/algos/i2c-algo-pca.c
+++ b/drivers/i2c/algos/i2c-algo-pca.c
@@ -22,6 +22,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/delay.h>
+#include <linux/jiffies.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/i2c.h>
@@ -186,14 +187,16 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
 	int numbytes = 0;
 	int state;
 	int ret;
-	int timeout = i2c_adap->timeout;
+	unsigned long timeout = jiffies + i2c_adap->timeout;
 
-	while ((state = pca_status(adap)) != 0xf8 && timeout--) {
-		msleep(10);
-	}
-	if (state != 0xf8) {
-		dev_dbg(&i2c_adap->dev, "bus is not idle. status is %#04x\n", state);
-		return -EAGAIN;
+	while (pca_status(adap) != 0xf8) {
+		if (time_before(jiffies, timeout)) {
+			msleep(10);
+		} else {
+			dev_dbg(&i2c_adap->dev, "bus is not idle. status is "
+				"%#04x\n", state);
+			return -EAGAIN;
+		}
 	}
 
 	DEB1("{{{ XFER %d messages\n", num);
diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
index 0cc8017b3f6..b9403fdfb6d 100644
--- a/drivers/i2c/busses/i2c-pca-isa.c
+++ b/drivers/i2c/busses/i2c-pca-isa.c
@@ -104,7 +104,7 @@ static struct i2c_adapter pca_isa_ops = {
 	.owner          = THIS_MODULE,
 	.algo_data	= &pca_isa_data,
 	.name		= "PCA9564/PCA9665 ISA Adapter",
-	.timeout	= 100,
+	.timeout	= HZ,
 };
 
 static int __devinit pca_isa_match(struct device *dev, unsigned int id)
diff --git a/include/linux/i2c-pca-platform.h b/include/linux/i2c-pca-platform.h
index 3d191873f2d..aba33759dec 100644
--- a/include/linux/i2c-pca-platform.h
+++ b/include/linux/i2c-pca-platform.h
@@ -6,7 +6,7 @@ struct i2c_pca9564_pf_platform_data {
 				 * not supplied (negative value), but it
 				 * cannot exit some error conditions then */
 	int i2c_clock_speed;	/* values are defined in linux/i2c-algo-pca.h */
-	int timeout;		/* timeout = this value * 10us */
+	int timeout;		/* timeout in jiffies */
 };
 
 #endif /* I2C_PCA9564_PLATFORM_H */