Re: [PATCH v3 0/8] Add the Quadspi driver for vf610-twr

On Thu, 2013-09-12 at 17:28 +0800, Huang Shijie wrote:

于 2013年09月11日 22:05, David Woodhouse 写道:

quoted

What*actually*  happens, on the wire(s), when the flash driver asks the
SPI controller to perform a transaction?

The LUT registers tell the controller how many wires are needed for a 
transaction.
For example, the read status only use a single line, while the quad read 
uses 4 lines.

Is this not something that could theoretically be provided by the caller
when it *makes* the transaction?

Conceptually speaking, could it not be an additional argument to
spi_write_then_read() ? 

After all, it's the *device* driver (m25p80.c etc.) which will know what
the transaction actually *is*, and how many lines the device will want
to use for each transaction?

-- 
dwmw2