I2C_RISEFALL_TIME
gpio->algo.udelay = I2C_RISEFALL_TIME;
udelay(I2C_RISEFALL_TIME);
udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
udelay(I2C_RISEFALL_TIME);
algo->udelay = I2C_RISEFALL_TIME;