diff options
Diffstat (limited to 'firmware/target')
| -rw-r--r-- | firmware/target/coldfire/i2c-coldfire.c | 34 |
1 files changed, 18 insertions, 16 deletions
diff --git a/firmware/target/coldfire/i2c-coldfire.c b/firmware/target/coldfire/i2c-coldfire.c index d743d046a7..06c196792f 100644 --- a/firmware/target/coldfire/i2c-coldfire.c +++ b/firmware/target/coldfire/i2c-coldfire.c @@ -30,7 +30,7 @@ static int i2c_start(volatile unsigned char *iface); static int i2c_wait_for_slave(volatile unsigned char *iface); static int i2c_outb(volatile unsigned char *iface, unsigned char byte); -inline void i2c_stop(volatile unsigned char *iface); +static inline void i2c_stop(volatile unsigned char *iface); /* --- Public functions - implementation --- */ @@ -76,6 +76,12 @@ void i2c_close(void) MBCR2 = 0; } +/* End I2C session on the given interface. */ +static inline void i2c_stop(volatile unsigned char *iface) +{ + iface[O_MBCR] &= ~MSTA; +} + /* * Writes bytes to a I2C device. * @@ -86,7 +92,7 @@ int i2c_write(volatile unsigned char *iface, unsigned char addr, { int i, rc; - if ( ! count) + if (count <= 0) return 0; rc = i2c_start(iface); @@ -118,7 +124,7 @@ int i2c_read(volatile unsigned char *iface, unsigned char addr, { int i, rc; - if ( ! count) + if (count <= 0) return 0; rc = i2c_start(iface); @@ -131,23 +137,25 @@ int i2c_read(volatile unsigned char *iface, unsigned char addr, /* Switch to Rx mode */ iface[O_MBCR] &= ~MTX; - iface[O_MBCR] &= ~TXAK; + + /* Turn on ACK generation if reading multiple bytes */ + if (count > 1) + iface[O_MBCR] &= ~TXAK; /* Dummy read */ rc = (int) iface[O_MBDR]; - for (i = 0; i < count; i++) + for (i = count; i > 0; i--) { rc = i2c_wait_for_slave(iface); if (rc < 0) return rc; - if (i == count-2) - /* Don't ACK the next-to-last byte */ + if (i == 2) + /* Don't ACK the last byte to be read from the slave */ iface[O_MBCR] |= TXAK; - - if (i == count-1) - /* Generate STOP before reading last byte */ + else if (i == 1) + /* Generate STOP before reading last byte received */ i2c_stop(iface); *buf++ = iface[O_MBDR]; @@ -233,9 +241,3 @@ int i2c_outb(volatile unsigned char *iface, unsigned char byte) return 0; } - -/* End I2C session on the given interface. */ -inline void i2c_stop(volatile unsigned char *iface) -{ - iface[O_MBCR] &= ~MSTA; -} |