SoC and i2c read/write transaction without stop in between.

Probably a problem in Linux driver i2c-altera.c

According to the documentation (Documentation/i2c/dev-interface):

ioctl (file, I2C_RDWR, struct i2c_rdwr_ioctl_data * msgset)

Do combined read / write transaction without stop in between.

Only valid if the adapter has I2C_FUNC_I2C. The argument is

a pointer to a

struct i2c_rdwr_ioctl_data {

struct i2c_msg * msgs; / * ptr to array of simple messages * /

int nmsgs; / * number of messages to exchange * /

}

The msgs [] themselves contain further pointers into data buffers.

If you’re looking at what I2C_M_RD I’m flag on

Overlaying the ivectl's

The i2c-altera.c driver has I2C_FUNC_I2C:

static u32 altr_i2c_func (struct i2c_adapter * adap)
 
{
 
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 
} 

The driver sets STOP when i2c_msg.len = 1 (last data byte):

static void altr_i2c_transfer (struct altr_i2c_dev * idev, u32 data)
 
{
 
/ * On the last byte, send STOP * /
 
if (idev-> msg_len == 1)
 
data | = ALTR_I2C_TFR_CMD_STO;
 
if (idev-> msg_len> 0)
 
writel (data, idev-> base + ALTR_I2C_TFR_CMD);
 
} 

Correctly put STOP after the last byte of the last message.

Any thoughts on how to fix this?