#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>
*
* 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);
}
/*
*
* 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);
}
/*
*
* 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);
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);
}
/*
*
* 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);
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);
}
/*
*
* 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);
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,
int numbytes = 0;
int state;
int ret;
- int timeout = i2c_adap->timeout;
+ int completed = 1;
+ 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 ((state = 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);
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;
}
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 */
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 */
case 0x30: /* Data byte in I2CDAT has been transmitted; NOT ACK has been received */
DEB2("NOT ACK received after data byte\n");
+ pca_stop(adap);
goto out;
case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
DEB2("Arbitration lost\n");
+ /*
+ * The PCA9564 data sheet (2006-09-01) says "A
+ * START condition will be transmitted when the
+ * bus becomes free (STOP or SCL and SDA high)"
+ * when the STA bit is set (p. 11).
+ *
+ * In case this won't work, try pca_reset()
+ * instead.
+ */
+ pca_start(adap);
goto out;
case 0x58: /* Data byte has been received; NOT ACK has been returned */
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",
break;
}
+ if (!completed)
+ goto out;
}
ret = curmsg;
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff