ADS1298_CLK_RATE_HZ
rate = ADS1298_CLK_RATE_HZ;
(DIV_ROUND_UP((x) * MICROHZ_PER_HZ, ADS1298_CLK_RATE_HZ))
#define ADS1298_SPI_BUS_SPEED_SLOW ADS1298_CLK_RATE_HZ