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

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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>
This commit is contained in:
Wolfram Sang
2009-03-28 21:34:45 +01:00
committed by Jean Delvare
parent 8e99ada8de
commit 2378bc09b9
3 changed files with 46 additions and 33 deletions
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41
drivers/i2c/algos/i2c-algo-pca.c
View File

@@ -60,14 +60,14 @@ static void pca9665_reset(void *pd)
* *
* returns after the start condition has occurred * 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); int sta = pca_get_con(adap);
DEB2("=== START\n"); DEB2("=== START\n");
sta |= I2C_PCA_CON_STA; sta |= I2C_PCA_CON_STA;
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI); sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
pca_set_con(adap, sta); pca_set_con(adap, sta);
pca_wait(adap); return pca_wait(adap);
} }
/* /*
@@ -75,14 +75,14 @@ static void pca_start(struct i2c_algo_pca_data *adap)
* *
* return after the repeated start condition has occurred * 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); int sta = pca_get_con(adap);
DEB2("=== REPEATED START\n"); DEB2("=== REPEATED START\n");
sta |= I2C_PCA_CON_STA; sta |= I2C_PCA_CON_STA;
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI); sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
pca_set_con(adap, sta); pca_set_con(adap, sta);
pca_wait(adap); return pca_wait(adap);
} }
/* /*
@@ -108,7 +108,7 @@ static void pca_stop(struct i2c_algo_pca_data *adap)
* *
* returns after the address has been sent * 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) struct i2c_msg *msg)
{ {
int sta = pca_get_con(adap); int sta = pca_get_con(adap);
@@ -125,7 +125,7 @@ static void pca_address(struct i2c_algo_pca_data *adap,
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI); sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
pca_set_con(adap, sta); pca_set_con(adap, sta);
pca_wait(adap); return pca_wait(adap);
} }
/* /*
@@ -133,7 +133,7 @@ static void pca_address(struct i2c_algo_pca_data *adap,
* *
* Returns after the byte has been transmitted * 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) __u8 b)
{ {
int sta = pca_get_con(adap); int sta = pca_get_con(adap);
@@ -143,7 +143,7 @@ static void pca_tx_byte(struct i2c_algo_pca_data *adap,
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI); sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
pca_set_con(adap, sta); pca_set_con(adap, sta);
pca_wait(adap); return pca_wait(adap);
} }
/* /*
@@ -163,7 +163,7 @@ static void pca_rx_byte(struct i2c_algo_pca_data *adap,
* *
* Returns after next byte has arrived. * 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 ack)
{ {
int sta = pca_get_con(adap); int sta = pca_get_con(adap);
@@ -174,7 +174,7 @@ static void pca_rx_ack(struct i2c_algo_pca_data *adap,
sta |= I2C_PCA_CON_AA; sta |= I2C_PCA_CON_AA;
pca_set_con(adap, sta); pca_set_con(adap, sta);
pca_wait(adap); return pca_wait(adap);
} }
static int pca_xfer(struct i2c_adapter *i2c_adap, static int pca_xfer(struct i2c_adapter *i2c_adap,
@@ -187,6 +187,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
int numbytes = 0; int numbytes = 0;
int state; int state;
int ret; int ret;
int completed = 1;
unsigned long timeout = jiffies + i2c_adap->timeout; unsigned long timeout = jiffies + i2c_adap->timeout;
while (pca_status(adap) != 0xf8) { while (pca_status(adap) != 0xf8) {
@@ -232,18 +233,19 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
switch (state) { switch (state) {
case 0xf8: /* On reset or stop the bus is idle */ case 0xf8: /* On reset or stop the bus is idle */
pca_start(adap); completed = pca_start(adap);
break; break;
case 0x08: /* A START condition has been transmitted */ case 0x08: /* A START condition has been transmitted */
case 0x10: /* A repeated start condition has been transmitted */ case 0x10: /* A repeated start condition has been transmitted */
pca_address(adap, msg); completed = pca_address(adap, msg);
break; break;
case 0x18: /* SLA+W has been transmitted; ACK has been received */ case 0x18: /* SLA+W has been transmitted; ACK has been received */
case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */ case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
if (numbytes < msg->len) { if (numbytes < msg->len) {
pca_tx_byte(adap, msg->buf[numbytes]); completed = pca_tx_byte(adap,
msg->buf[numbytes]);
numbytes++; numbytes++;
break; break;
} }
@@ -251,7 +253,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
if (curmsg == num) if (curmsg == num)
pca_stop(adap); pca_stop(adap);
else else
pca_repeated_start(adap); completed = pca_repeated_start(adap);
break; break;
case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */ case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
@@ -260,21 +262,22 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
goto out; goto out;
case 0x40: /* SLA+R has been transmitted; ACK has been received */ 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; break;
case 0x50: /* Data bytes has been received; ACK has been returned */ case 0x50: /* Data bytes has been received; ACK has been returned */
if (numbytes < msg->len) { if (numbytes < msg->len) {
pca_rx_byte(adap, &msg->buf[numbytes], 1); pca_rx_byte(adap, &msg->buf[numbytes], 1);
numbytes++; numbytes++;
pca_rx_ack(adap, numbytes < msg->len - 1); completed = pca_rx_ack(adap,
numbytes < msg->len - 1);
break; break;
} }
curmsg++; numbytes = 0; curmsg++; numbytes = 0;
if (curmsg == num) if (curmsg == num)
pca_stop(adap); pca_stop(adap);
else else
pca_repeated_start(adap); completed = pca_repeated_start(adap);
break; break;
case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */ case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
@@ -297,7 +300,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
if (curmsg == num) if (curmsg == num)
pca_stop(adap); pca_stop(adap);
else else
pca_repeated_start(adap); completed = pca_repeated_start(adap);
} else { } else {
DEB2("NOT ACK sent after data byte received. " DEB2("NOT ACK sent after data byte received. "
"Not final byte. numbytes %d. len %d\n", "Not final byte. numbytes %d. len %d\n",
@@ -323,6 +326,8 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
break; break;
} }
if (!completed)
goto out;
} }
ret = curmsg; ret = curmsg;

18
drivers/i2c/busses/i2c-pca-isa.c
View File

@@ -23,6 +23,7 @@
#include <linux/module.h> #include <linux/module.h>
#include <linux/moduleparam.h> #include <linux/moduleparam.h>
#include <linux/delay.h> #include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/interrupt.h> #include <linux/interrupt.h>
#include <linux/wait.h> #include <linux/wait.h>
@@ -43,6 +44,7 @@ static int irq = -1;
* in the actual clock rate */ * in the actual clock rate */
static int clock = 59000; static int clock = 59000;
static struct i2c_adapter pca_isa_ops;
static wait_queue_head_t pca_wait; static wait_queue_head_t pca_wait;
static void pca_isa_writebyte(void *pd, int reg, int val) 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) static int pca_isa_waitforcompletion(void *pd)
{ {
int ret = 0; long ret = ~0;
unsigned long timeout;
if (irq > -1) { if (irq > -1) {
ret = wait_event_interruptible(pca_wait, ret = wait_event_interruptible_timeout(pca_wait,
pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI); pca_isa_readbyte(pd, I2C_PCA_CON)
& I2C_PCA_CON_SI, pca_isa_ops.timeout);
} else { } 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); udelay(100);
} }
return ret; return ret > 0;
} }
static void pca_isa_resetchip(void *pd) static void pca_isa_resetchip(void *pd)

20
drivers/i2c/busses/i2c-pca-platform.c
View File

@@ -15,6 +15,7 @@
#include <linux/init.h> #include <linux/init.h>
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/delay.h> #include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/errno.h> #include <linux/errno.h>
#include <linux/i2c.h> #include <linux/i2c.h>
#include <linux/interrupt.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) static int i2c_pca_pf_waitforcompletion(void *pd)
{ {
struct i2c_pca_pf_data *i2c = pd; struct i2c_pca_pf_data *i2c = pd;
int ret = 0; long ret = ~0;
unsigned long timeout;
if (i2c->irq) { 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->algo_data.read_byte(i2c, I2C_PCA_CON)
& I2C_PCA_CON_SI); & I2C_PCA_CON_SI, i2c->adap.timeout);
} else { } else {
/* /* Do polling */
* Do polling... timeout = jiffies + i2c->adap.timeout;
* XXX: Could get stuck in extreme cases! while (((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
* Maybe add timeout, but using irqs is preferred anyhow.
*/
while ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
& I2C_PCA_CON_SI) == 0) & I2C_PCA_CON_SI) == 0)
&& (ret = time_before(jiffies, timeout)))
udelay(100); udelay(100);
} }
return ret; return ret > 0;
} }
static void i2c_pca_pf_dummyreset(void *pd) static void i2c_pca_pf_dummyreset(void *pd)