ad7877_write
ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);