Hello Michael, Thanks for posting your patches in plain text.
Michael Durrant wrote: > drivers_i2c_fsl_i2c.patch > - need to set I2C to be idle according to the MCF5282 user's manual > > If I2SR[IBB] is set when the I2C bus module is enabled, > execute the following code sequence before proceeding with > normal initialization code. This issues a STOP command to the > slave device, placing it in idle state as if it were just > power-cycled on. > > I2CR = 0x0 > I2CR = 0xA > dummy read of I2DR > I2SR = 0x0 > I2CR = 0x0 > > Signed-off-by: David Wu <davi...@arcturusnetworks.com> > Signed-off-by: Michael Durrant <mdurr...@arcturusnetworks.com> > --- > drivers/i2c/fsl_i2c.c | 13 +++++++++++++ > 1 files changed, 13 insertions(+), 0 deletions(-) > > diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c > index 2241990..bce750c 100644 > --- a/drivers/i2c/fsl_i2c.c > +++ b/drivers/i2c/fsl_i2c.c > @@ -251,12 +251,25 @@ i2c_init(int speed, int slaveadd) > #endif > } > > +static __inline__ int i2c_set_idle(void) > +{ > + writeb(0, &i2c_dev[i2c_bus_num]->cr); > + writeb(I2C_CR_MEN | I2C_CR_MSTA, &i2c_dev[i2c_bus_num]->cr); > + readb(&i2c_dev[i2c_bus_num]->dr); > + writeb(0, &i2c_dev[i2c_bus_num]->sr); > + writeb(0, &i2c_dev[i2c_bus_num]->cr); > + writeb(I2C_CR_MEN, &i2c_dev[i2c_bus_num]->cr); > +} > + > static int > i2c_wait4bus(void) > { > unsigned long long timeval = get_ticks(); > const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT); > > + if (readb(&i2c_dev[i2c_bus_num]->sr) & I2C_SR_MBB) > + i2c_set_idle(); > + > while (readb(&i2c_dev[i2c_bus_num]->sr) & I2C_SR_MBB) { > if ((get_ticks() - timeval) > timeout) > return -1; Hmm.. I can;t find this for example in the MPC8360ERM.pdf, which uses also this driver ... So I vote for activating this only, if this driver is used for __M68K__ ... Also, you write, that this sequence is necessary before normal initialization code, but i2c_wait4bus() is called from i2c_read() and i2c_write(), so the I2C bus is long ago initialized ... or what do you mean with "normal initialization code" ? Also, whats with multimaster systems? Your code maybe cuts a running data transmission. The MPC8360ERM.pdf manual says "check the MBB bit, if the bus is free, before switching to master mode", thats what actual code did ... so, I want this only activated, if __M68K__ is defined ... bye Heiko -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot