David Brownell wrote:
This is actually not needed. Clocks are set through the setup() method
...
Where is it supposed to call setup? I guess it's anyway gonna be
per-transfer, right?
Or am I missing something?
When the device is created, the core calls setup() to get things like
chipselect polarity sorted out and put into the inactive state. That
matches the board-specific defaults associated with that device, which
would be a function of voltage, routing, and more.
And from then on, it'd be rare to ever call setup() again ... though
drivers certainly could do that between spi_message interactions with
a given device.
No, suppose there're two devices behind the same SPI bus that have
different clock constraints. As active SPI device change may well happen
when each new message is processed, we'll need to set up clocks again
for each message. Right?
Vitaly
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