i2c-algo-pca: Rework waiting for a free bus
Wolfram Sang [Sat, 28 Mar 2009 20:34:45 +0000 (21:34 +0100)]
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>

arch/sh/boards/board-sh7785lcr.c
drivers/i2c/algos/i2c-algo-pca.c
drivers/i2c/busses/i2c-pca-isa.c
include/linux/i2c-pca-platform.h

index 94c0296..6f94f17 100644 (file)
@@ -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 = {
index a8e51bd..9e134fa 100644 (file)
@@ -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);
index 0cc8017..b9403fd 100644 (file)
@@ -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)
index 3d19187..aba3375 100644 (file)
@@ -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 */