Based on the I3C TCRI specification, the rules for determining the I3C
mode are as follows:
I3C SCL rate > 8MHz: use SDR0, as SDR1 has a maximum data rate of 8MHz
I3C SCL rate > 6MHz: use SDR1, as SDR2 has a maximum data rate of 6MHz
I3C SCL rate > 4MHz: use SDR2, as SDR3 has a maximum data rate of 4MHz
I3C SCL rate > 2MHz: use SDR3, as SDR4 has a maximum data rate of 2MHz
Otherwise, use SDR4
Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
Link: https://lore.kernel.org/r/20240826033821.175591-1-billy_tsai@aspeedtech.comSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>