Hello Joakim, Joakim Tjernlund wrote: >> 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 ... > > All true. This cannot go in as is. What you need is a I2C reset sequence > as the above isn't enough in the general case. Michael, have a look at the > kernel driver, it has some fixup code you could borrow.
Michael: Maybe you take a look in u-boot:board/keymile/common/common.c i2c_init_board(), there is a I2C reset sequence for 83xx based boards from keymile, which use this i2c driver. Maybe its time to move this code in the i2c driver? 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