diff options
| -rw-r--r-- | drivers/i2c/algos/i2c-algo-bit.c | 42 | ||||
| -rw-r--r-- | include/linux/i2c-algo-bit.h | 6 |
2 files changed, 26 insertions, 22 deletions
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index fc16f9d268a..d9d0ec49e60 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -57,19 +57,19 @@ static int bit_test; /* see if the line-setting functions work */ static inline void sdalo(struct i2c_algo_bit_data *adap) { setsda(adap,0); - udelay(adap->udelay); + udelay((adap->udelay + 1) / 2); } static inline void sdahi(struct i2c_algo_bit_data *adap) { setsda(adap,1); - udelay(adap->udelay); + udelay((adap->udelay + 1) / 2); } static inline void scllo(struct i2c_algo_bit_data *adap) { setscl(adap,0); - udelay(adap->udelay); + udelay(adap->udelay / 2); } /* @@ -111,18 +111,19 @@ static void i2c_start(struct i2c_algo_bit_data *adap) { /* assert: scl, sda are high */ DEBPROTO(printk("S ")); - sdalo(adap); + setsda(adap, 0); + udelay(adap->udelay); scllo(adap); } static void i2c_repstart(struct i2c_algo_bit_data *adap) { - /* scl, sda may not be high */ + /* assert: scl is low */ DEBPROTO(printk(" Sr ")); - setsda(adap,1); + sdahi(adap); sclhi(adap); - - sdalo(adap); + setsda(adap, 0); + udelay(adap->udelay); scllo(adap); } @@ -133,7 +134,8 @@ static void i2c_stop(struct i2c_algo_bit_data *adap) /* assert: scl is low */ sdalo(adap); sclhi(adap); - sdahi(adap); + setsda(adap, 1); + udelay(adap->udelay); } @@ -156,18 +158,16 @@ static int i2c_outb(struct i2c_adapter *i2c_adap, char c) for ( i=7 ; i>=0 ; i-- ) { sb = c & ( 1 << i ); setsda(adap,sb); - udelay(adap->udelay); + udelay((adap->udelay + 1) / 2); DEBPROTO(printk(KERN_DEBUG "%d",sb!=0)); if (sclhi(adap)<0) { /* timed out */ - sdahi(adap); /* we don't want to block the net */ DEB2(printk(KERN_DEBUG " i2c_outb: 0x%02x, timeout at bit #%d\n", c&0xff, i)); return -ETIMEDOUT; }; /* do arbitration here: * if ( sb && ! getsda(adap) ) -> ouch! Get out of here. */ - setscl(adap, 0 ); - udelay(adap->udelay); + scllo(adap); } sdahi(adap); if (sclhi(adap)<0){ /* timeout */ @@ -204,7 +204,8 @@ static int i2c_inb(struct i2c_adapter *i2c_adap) indata *= 2; if ( getsda(adap) ) indata |= 0x01; - scllo(adap); + setscl(adap, 0); + udelay(i == 7 ? adap->udelay / 2 : adap->udelay); } /* assert: scl is low */ DEB2(printk(KERN_DEBUG "i2c_inb: 0x%02x\n", indata & 0xff)); @@ -315,9 +316,9 @@ static int try_address(struct i2c_adapter *i2c_adap, if (ret == 1 || i == retries) break; i2c_stop(adap); - udelay(5/*adap->udelay*/); - i2c_start(adap); udelay(adap->udelay); + yield(); + i2c_start(adap); } DEB2(if (i) printk(KERN_DEBUG "i2c-algo-bit.o: Used %d tries to %s client at 0x%02x : %s\n", @@ -377,20 +378,21 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) if (msg->flags & I2C_M_NO_RD_ACK) continue; + /* assert: sda is high */ if ( count > 0 ) { /* send ack */ - sdalo(adap); + setsda(adap, 0); + udelay((adap->udelay + 1) / 2); DEBPROTO(printk(" Am ")); } else { - sdahi(adap); /* neg. ack on last byte */ + /* neg. ack on last byte */ + udelay((adap->udelay + 1) / 2); DEBPROTO(printk(" NAm ")); } if (sclhi(adap)<0) { /* timeout */ - sdahi(adap); printk(KERN_ERR "i2c-algo-bit.o: readbytes: Timeout at ack\n"); return -ETIMEDOUT; }; scllo(adap); - sdahi(adap); /* Some SMBus transactions require that we receive the transaction length as the first read byte. */ diff --git a/include/linux/i2c-algo-bit.h b/include/linux/i2c-algo-bit.h index d91dab88635..9ee0f800592 100644 --- a/include/linux/i2c-algo-bit.h +++ b/include/linux/i2c-algo-bit.h @@ -38,8 +38,10 @@ struct i2c_algo_bit_data { int (*getscl) (void *data); /* local settings */ - int udelay; /* half-clock-cycle time in microsecs */ - /* i.e. clock is (500 / udelay) KHz */ + int udelay; /* half clock cycle time in us, + minimum 2 us for fast-mode I2C, + minimum 5 us for standard-mode I2C and SMBus, + maximum 50 us for SMBus */ int timeout; /* in jiffies */ }; |