lkml.org 
[lkml]   [2014]   [Jul]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [RFC PATCH 1/2] spi: Add support for Zynq QSPI controller
From
Hi Mark,

On Thu, Jul 10, 2014 at 5:31 PM, Mark Brown <broonie@kernel.org> wrote:
> On Thu, Jul 10, 2014 at 04:03:19PM +0530, Harini Katakam wrote:
>
>> OK. Correct me if I'm wrong but announcing this support in master->flags is
>> just to say the controller supports it - Like Punnaiah mentioned in the other
>
> No, it's broken to set this if there is no ability to use it.
>
>> mail, nothing specific needs to be done from the controller driver to enable
>> dual/quad support. This is at the SOC/IP level.
>
> How does the client driver select the width to use for a transfer?

This controller is meant to be used only with flash devices.
The flash devices' supported width will be reflected in a table in MTD layer.
When selecting, priority is given to quad over dual and single in the MTD and
it will send commands using the supported tx/rx bus width accordingly.
About the supported bus width on board, tx-bus-width and rx-bus-width
properties in dts will have the info; which I believe spi core uses.

Regards,
Harini


\
 
 \ /
  Last update: 2014-07-10 15:21    [W:0.096 / U:3.200 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site