>>> [EMAIL PROTECTED]:/# i2cdetect -y 0
>>> 0 1 2 3 4 5 6 7 8 9 a b c d e f
>>> 00: -- -- -- -- -- -- -- -- -- -- -- -- --
>>> 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
>>> 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
>>> 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
>>> 40: -- -- -- -- -- -- -- -- -- -- -- -- 4c -- -- --
>>> 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
>>> 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
>>> 70: -- -- -- -- -- -- -- --
>> but i cant access the MAX1236 on slave address 0x34.
>> (0x4c is the onbard LM90)
>
> Maybe it's not wired properly?
>
> If it is wired properly, then another possibility is that the MAX1236
> is doing clock stretching beyond what the CS5536 supports...
>
>> Does "I2C no" means the CS5536 is a plain smbus without i2c support?
>
> Yes and no. It means that the scx200_acb driver runs the CS5536 in
> SMBus mode without plain I2C support. But there is also the scx200_i2c
> driver (which I would love to see go away in favor of i2c-gpio but
> that's another story) which can use the same pins as GPIO to do plain
> I2C. If I read the MAX1236 datasheet properly, it uses transactions
> which aren't part of the SMBus set, so you may need to use the
> scx200_i2c driver, depending on what exactly you need to do with the
> MAX1236. There are still a few SMBus transactions which should work
> though, and that may be enough.
Hi,
A driver that should work with this chip is part of the
iio subsystem, so I have a fair bit of familiarity (though
only via 1238 rather than this exact model)
Done a bit of digging around and my original test code was
#include <fcntl.h>
#include "i2c-dev.h"
int main(int argc, char* argv[])
{
struct i2c_smbus_ioctl_data arg;
union i2c_smbus_data data;
int adaptor_nr=atoi(argv[1]); //check this
char filename[20];
sprintf(filename,"/dev/i2c-%d",adaptor_nr);
int file;
if((file = open(filename, O_RDWR))<0)
{
printf("could not open /dev/i2c-%u\n", adaptor_nr);
exit(-1);
}
if(ioctl(file,I2C_SLAVE, 0x34) < 0)
{
printf("could not set slave address \n");
return -1;
}
arg.size = I2C_SMBUS_BYTE;
arg.read_write = I2C_SMBUS_WRITE;
arg.command = I2C_SMBUS_BYTE;
data.byte = 8;
arg.data = &data;
char buf[2] = {0x79, 0x92};
write(file, buf,2);
int i;
for(i = 0; i < 20; i++)
{
read(file,buf,2);
unsigned int a =0;
a = (buf[0] & 0xF) << 8 | buf[1] ;
printf("reading %u\n",a);
sleep(1);
}
}
No idea why I did it without using the smbus_write commands
though. The iio driver is i2c_transfers I'm afraid.
as for i2c detect, I've just blugeoned it into building for
the pxa271 board I'm using and it picks up a max1239 just fine.
Good luck!
Jonathan
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