LED_GPIO_CFG
ret = smsc75xx_read_reg(dev, LED_GPIO_CFG, &buf);
ret = smsc75xx_write_reg(dev, LED_GPIO_CFG, buf);
ret = smsc95xx_read_reg(dev, LED_GPIO_CFG, &read_buf);
ret = smsc95xx_write_reg(dev, LED_GPIO_CFG, read_buf);