diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/i2c/fsl_i2c.c | 20 |
1 files changed, 6 insertions, 14 deletions
diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c index b0e65fcf65..18b8848ced 100644 --- a/drivers/i2c/fsl_i2c.c +++ b/drivers/i2c/fsl_i2c.c @@ -428,22 +428,14 @@ fsl_i2c_read(struct i2c_adapter *adap, u8 chip_addr, uint offset, int olen, if (i2c_wait4bus(adap) < 0) return -1; - /* To handle the need of I2C devices that require to write few bytes - * (more than 4 bytes of address as in the case of else part) - * of data before reading, Negative equivalent of dlen(bytes to write) - * is passed, but used the +ve part of len for writing data + /* Some drivers use offset lengths in excess of 4 bytes. These drivers + * adhere to the following convention: + * - the offset length is passed as negative (that is, the absolute + * value of olen is the actual offset length) + * - the offset itself is passed in data, which is overwritten by the + * subsequent read operation */ if (olen < 0) { - /* Generate a START and send the Address and - * the Tx Bytes to the slave. - * "START: Address: Write bytes data[len]" - * IF part supports writing any number of bytes in contrast - * to the else part, which supports writing address offset - * of upto 4 bytes only. - * bytes that need to be written are passed in - * "data", which will eventually keep the data READ, - * after writing the len bytes out of it - */ if (i2c_write_addr(adap, chip_addr, I2C_WRITE_BIT, 0) != 0) ret = __i2c_write(adap, data, len); |
