diff options
Diffstat (limited to 'drivers/i2c/algos/i2c-algo-pcf.c')
| -rw-r--r-- | drivers/i2c/algos/i2c-algo-pcf.c | 44 |
1 files changed, 41 insertions, 3 deletions
diff --git a/drivers/i2c/algos/i2c-algo-pcf.c b/drivers/i2c/algos/i2c-algo-pcf.c index 66e681cb33d1e..8d087dac32afc 100644 --- a/drivers/i2c/algos/i2c-algo-pcf.c +++ b/drivers/i2c/algos/i2c-algo-pcf.c @@ -78,7 +78,6 @@ static void i2c_stop(struct i2c_algo_pcf_data *adap) set_pcf(adap, 1, I2C_PCF_STOP); } - static int wait_for_bb(struct i2c_algo_pcf_data *adap) { int timeout = DEF_TIMEOUT; @@ -109,6 +108,26 @@ static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) { adap->waitforpin(); *status = get_pcf(adap, 1); } + if (*status & I2C_PCF_LAB) { + DEB2(printk(KERN_INFO + "i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n", + *status)); + /* Cleanup from LAB-- reset and enable ESO. + * This resets the PCF8584; since we've lost the bus, no + * further attempts should be made by callers to clean up + * (no i2c_stop() etc.) + */ + set_pcf(adap, 1, I2C_PCF_PIN); + set_pcf(adap, 1, I2C_PCF_ESO); + /* TODO: we should pause for a time period sufficient for any + * running I2C transaction to complete-- the arbitration + * logic won't work properly until the next START is seen. + */ + DEB2(printk(KERN_INFO + "i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n", + get_pcf(adap,1))); + return(-EINTR); + } #endif if (timeout <= 0) return(-1); @@ -188,16 +207,22 @@ static inline int try_address(struct i2c_algo_pcf_data *adap, unsigned char addr, int retries) { int i, status, ret = -1; + int wfp; for (i=0;i<retries;i++) { i2c_outb(adap, addr); i2c_start(adap); status = get_pcf(adap, 1); - if (wait_for_pin(adap, &status) >= 0) { + if ((wfp = wait_for_pin(adap, &status)) >= 0) { if ((status & I2C_PCF_LRB) == 0) { i2c_stop(adap); break; /* success! */ } } + if (wfp == -EINTR) { + /* arbitration lost */ + udelay(adap->udelay); + return -EINTR; + } i2c_stop(adap); udelay(adap->udelay); } @@ -219,6 +244,10 @@ static int pcf_sendbytes(struct i2c_adapter *i2c_adap, const char *buf, i2c_outb(adap, buf[wrcount]); timeout = wait_for_pin(adap, &status); if (timeout) { + if (timeout == -EINTR) { + /* arbitration lost */ + return -EINTR; + } i2c_stop(adap); dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n"); return -EREMOTEIO; /* got a better one ?? */ @@ -247,11 +276,16 @@ static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf, { int i, status; struct i2c_algo_pcf_data *adap = i2c_adap->algo_data; + int wfp; /* increment number of bytes to read by one -- read dummy byte */ for (i = 0; i <= count; i++) { - if (wait_for_pin(adap, &status)) { + if ((wfp = wait_for_pin(adap, &status))) { + if (wfp == -EINTR) { + /* arbitration lost */ + return -EINTR; + } i2c_stop(adap); dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n"); return (-1); @@ -366,6 +400,10 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap, /* Wait for PIN (pending interrupt NOT) */ timeout = wait_for_pin(adap, &status); if (timeout) { + if (timeout == -EINTR) { + /* arbitration lost */ + return (-EINTR); + } i2c_stop(adap); DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting " "for PIN(1) in pcf_xfer\n");) |