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>
diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
index 9e134fa..f68e5f8 100644
--- a/drivers/i2c/algos/i2c-algo-pca.c
+++ b/drivers/i2c/algos/i2c-algo-pca.c
@@ -60,14 +60,14 @@
*
* returns after the start condition has occurred
*/
-static void pca_start(struct i2c_algo_pca_data *adap)
+static int pca_start(struct i2c_algo_pca_data *adap)
{
int sta = pca_get_con(adap);
DEB2("=== START\n");
sta |= I2C_PCA_CON_STA;
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
pca_set_con(adap, sta);
- pca_wait(adap);
+ return pca_wait(adap);
}
/*
@@ -75,14 +75,14 @@
*
* return after the repeated start condition has occurred
*/
-static void pca_repeated_start(struct i2c_algo_pca_data *adap)
+static int pca_repeated_start(struct i2c_algo_pca_data *adap)
{
int sta = pca_get_con(adap);
DEB2("=== REPEATED START\n");
sta |= I2C_PCA_CON_STA;
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
pca_set_con(adap, sta);
- pca_wait(adap);
+ return pca_wait(adap);
}
/*
@@ -108,7 +108,7 @@
*
* returns after the address has been sent
*/
-static void pca_address(struct i2c_algo_pca_data *adap,
+static int pca_address(struct i2c_algo_pca_data *adap,
struct i2c_msg *msg)
{
int sta = pca_get_con(adap);
@@ -125,7 +125,7 @@
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
pca_set_con(adap, sta);
- pca_wait(adap);
+ return pca_wait(adap);
}
/*
@@ -133,7 +133,7 @@
*
* Returns after the byte has been transmitted
*/
-static void pca_tx_byte(struct i2c_algo_pca_data *adap,
+static int pca_tx_byte(struct i2c_algo_pca_data *adap,
__u8 b)
{
int sta = pca_get_con(adap);
@@ -143,7 +143,7 @@
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
pca_set_con(adap, sta);
- pca_wait(adap);
+ return pca_wait(adap);
}
/*
@@ -163,7 +163,7 @@
*
* Returns after next byte has arrived.
*/
-static void pca_rx_ack(struct i2c_algo_pca_data *adap,
+static int pca_rx_ack(struct i2c_algo_pca_data *adap,
int ack)
{
int sta = pca_get_con(adap);
@@ -174,7 +174,7 @@
sta |= I2C_PCA_CON_AA;
pca_set_con(adap, sta);
- pca_wait(adap);
+ return pca_wait(adap);
}
static int pca_xfer(struct i2c_adapter *i2c_adap,
@@ -187,6 +187,7 @@
int numbytes = 0;
int state;
int ret;
+ int completed = 1;
unsigned long timeout = jiffies + i2c_adap->timeout;
while (pca_status(adap) != 0xf8) {
@@ -232,18 +233,19 @@
switch (state) {
case 0xf8: /* On reset or stop the bus is idle */
- pca_start(adap);
+ completed = pca_start(adap);
break;
case 0x08: /* A START condition has been transmitted */
case 0x10: /* A repeated start condition has been transmitted */
- pca_address(adap, msg);
+ completed = pca_address(adap, msg);
break;
case 0x18: /* SLA+W has been transmitted; ACK has been received */
case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
if (numbytes < msg->len) {
- pca_tx_byte(adap, msg->buf[numbytes]);
+ completed = pca_tx_byte(adap,
+ msg->buf[numbytes]);
numbytes++;
break;
}
@@ -251,7 +253,7 @@
if (curmsg == num)
pca_stop(adap);
else
- pca_repeated_start(adap);
+ completed = pca_repeated_start(adap);
break;
case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
@@ -260,21 +262,22 @@
goto out;
case 0x40: /* SLA+R has been transmitted; ACK has been received */
- pca_rx_ack(adap, msg->len > 1);
+ completed = pca_rx_ack(adap, msg->len > 1);
break;
case 0x50: /* Data bytes has been received; ACK has been returned */
if (numbytes < msg->len) {
pca_rx_byte(adap, &msg->buf[numbytes], 1);
numbytes++;
- pca_rx_ack(adap, numbytes < msg->len - 1);
+ completed = pca_rx_ack(adap,
+ numbytes < msg->len - 1);
break;
}
curmsg++; numbytes = 0;
if (curmsg == num)
pca_stop(adap);
else
- pca_repeated_start(adap);
+ completed = pca_repeated_start(adap);
break;
case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
@@ -297,7 +300,7 @@
if (curmsg == num)
pca_stop(adap);
else
- pca_repeated_start(adap);
+ completed = pca_repeated_start(adap);
} else {
DEB2("NOT ACK sent after data byte received. "
"Not final byte. numbytes %d. len %d\n",
@@ -323,6 +326,8 @@
break;
}
+ if (!completed)
+ goto out;
}
ret = curmsg;
diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
index b9403fd..0ed68e2 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 @@
* 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_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 51d179b..df5e593 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 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)