i2c-algo-pca: Use timeout for checking the state machine

We now timeout also if the state machine does not change within the
given time. For that, the driver-specific completion-functions are
extended to return true or false depending on the timeout. This then
gets checked in the algorithm.

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

2 files changed, 23 insertions, 15 deletions

diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
index b9403fdfb6d8..0ed68e2ccd22 100644
--- a/drivers/i2c/busses/i2c-pca-isa.c
+++ b/drivers/i2c/busses/i2c-pca-isa.c
@@ -23,6 +23,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/delay.h>
+#include <linux/jiffies.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/wait.h>
@@ -43,6 +44,7 @@ static int irq = -1;
  * in the actual clock rate */
 static int clock  = 59000;
 
+static struct i2c_adapter pca_isa_ops;
 static wait_queue_head_t pca_wait;
 
 static void pca_isa_writebyte(void *pd, int reg, int val)
@@ -69,16 +71,22 @@ static int pca_isa_readbyte(void *pd, int reg)
 
 static int pca_isa_waitforcompletion(void *pd)
 {
-        int ret = 0;
+        long ret = ~0;
+        unsigned long timeout;
 
         if (irq > -1) {
-                ret = wait_event_interruptible(pca_wait,
-                                               pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI);
+                ret = wait_event_interruptible_timeout(pca_wait,
+                                pca_isa_readbyte(pd, I2C_PCA_CON)
+                                & I2C_PCA_CON_SI, pca_isa_ops.timeout);
         } else {
-                while ((pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
+                /* Do polling */
+                timeout = jiffies + pca_isa_ops.timeout;
+                while (((pca_isa_readbyte(pd, I2C_PCA_CON)
+                                & I2C_PCA_CON_SI) == 0)
+                                && (ret = time_before(jiffies, timeout)))
                         udelay(100);
         }
-        return ret;
+        return ret > 0;
 }
 
 static void pca_isa_resetchip(void *pd)
diff --git a/drivers/i2c/busses/i2c-pca-platform.c b/drivers/i2c/busses/i2c-pca-platform.c
index 51d179bbddf9..df5e593a1d76 100644
--- a/drivers/i2c/busses/i2c-pca-platform.c
+++ b/drivers/i2c/busses/i2c-pca-platform.c
@@ -15,6 +15,7 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
+#include <linux/jiffies.h>
 #include <linux/errno.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
@@ -81,24 +82,23 @@ static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)
 static int i2c_pca_pf_waitforcompletion(void *pd)
 {
         struct i2c_pca_pf_data *i2c = pd;
-        int ret = 0;
+        long ret = ~0;
+        unsigned long timeout;
 
         if (i2c->irq) {
-                ret = wait_event_interruptible(i2c->wait,
+                ret = wait_event_interruptible_timeout(i2c->wait,
                         i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
-                        & I2C_PCA_CON_SI);
+                        & I2C_PCA_CON_SI, i2c->adap.timeout);
         } else {
-                /*
-                 * Do polling...
-                 * XXX: Could get stuck in extreme cases!
-                 *      Maybe add timeout, but using irqs is preferred anyhow.
-                 */
-                while ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
+                /* Do polling */
+                timeout = jiffies + i2c->adap.timeout;
+                while (((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
                                 & I2C_PCA_CON_SI) == 0)
+                                && (ret = time_before(jiffies, timeout)))
                         udelay(100);
         }
 
-        return ret;
+        return ret > 0;
 }
 
 static void i2c_pca_pf_dummyreset(void *pd)