i2c block read problemsss

westermani · 05-08-2008, 03:17 AM

Hi,

i hope someone can help me...here is my trouble

i'm using i2c from user space on an ARM of atmel. I can read and write byte with the SMBus functions but when i try to read blocks this error apear

i2c_adapter i2c-0: Block read not supported under i2c emulation!!

the function is
ret = i2c_smbus_read_block_data(fd, 0x00, buff);

what can i do?? i use i2c_smbus_write_block_data and it works and when i use write(fd, buff, 8) it works to but when i try the read operation it fails...

thank you very much for helping me and sorry of my bad english, i'm trying to learn it.

westermani

Simon Bridge · 05-08-2008, 03:27 AM

the problemsss isss block readssss... the sssolussshion isss deathhhhh...

Code:

case I2C_SMBUS_BLOCK_DATA:
		if (read_write == I2C_SMBUS_READ) {
			printk("i2c-core.o: Block read not supported under "
			       "I2C emulation!\n");
		return -1;

You need to stop using i2c emulation if you want to use block reads.
Perhaps you are doing this in , um, userspace?
http://xgoat.com/wp/2007/11/11/using...pace-in-linux/

westermani · 05-08-2008, 04:01 AM

sorry, i don't understand you

yes, i'm using this from userspace, but how can i stop the emulation??maybe i need other functions to handle the i2c bus??or i have to change the driver definition??

Simon Bridge · 05-08-2008, 05:12 AM

The link I provided has a howto for using i2c from userspace.

westermani · 05-08-2008, 08:13 AM

yes, i now and i have seen it, but now my problem is that linux doesn't support read block and i need it. what can i do to change it??i have to recompile the i2c adapter or can i change it by the ioctl function??

thank you for your patient...

regards