SPI: cs_change usage

[Atsushi Nemoto <anemo@mba.ocn.ne.jp>]

Hi.  Now I'm looking into new SPI subsystem and I have a question.

In spi.h, cs_change's usage is described as follows:

> * (i) If the transfer isn't the last one in the message, this flag is
> * used to make the chipselect briefly go inactive in the middle of the
> * message.  Toggling chipselect in this way may be needed to terminate
> * a chip command, letting a single spi_message perform all of group of
> * chip transactions together.
> *
> * (ii) When the transfer is the last one in the message, the chip may
> * stay selected until the next transfer.  This is purely a performance
> * hint; the controller driver may need to select a different device
> * for the next message.

I'm confused by the last paragraph.  In the last transfer, does
"cs_change = 1" mean "keep the chipselect activated" ?  Or the
paragraph is saying "I can set cs_change to zero to keep the
chipselect activated after the message" ?

---
Atsushi Nemoto
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/