I2C_CON_MST
con |= I2C_CON_MST;
AM335X_I2C_CON, I2C_CON_EN | I2C_CON_MST | I2C_CON_STP);
while (I2C_READ_REG(sc, AM335X_I2C_CON) & I2C_CON_MST) {