REVO51_PT2258S_SCL
envy_gpio_i2c_start_bit(sc, REVO51_PT2258S_SDA, REVO51_PT2258S_SCL);
envy_gpio_i2c_byte_out(sc, REVO51_PT2258S_SDA, REVO51_PT2258S_SCL,
REVO51_PT2258S_SCL, data);
REVO51_PT2258S_SCL, attn);
REVO51_PT2258S_SCL, attn);
envy_gpio_i2c_stop_bit(sc, REVO51_PT2258S_SDA, REVO51_PT2258S_SCL);