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On 03/05/2013 12:21 PM, Jagan Teki wrote:
Hi Tom,
On Tue, Mar 5, 2013 at 10:38 PM, Tom Rini trini@ti.com wrote: On 03/05/2013 12:00 PM, Jagan Teki wrote:
Hi Tom,
On Tue, Mar 5, 2013 at 2:38 AM, Tom Rini trini@ti.com wrote:
On Sat, Mar 02, 2013 at 01:59:38PM +0530, Jagan Teki wrote:
[snip]
Since these changes I have sent long back, I am just re-modified the framework to add new features at the same time with backward comparability for current commands.
Current command setup: sf write sf read sf update
Changed command set: [no changes in the argument count] sf write --- current command sf write.pp -- same as sf write sf write.qp -- quad program
sf read -- current read sf read.af --- array flast read, same as sf read sf read.as -- array slow read sf read.do --- dual out sf read.qo -- quad out sf read.dio -- dual io sf read.qio -- quad io
sf update -- current update sf update.pp.af -- write page program, read array fast, same as sf update sf update.pp.as - write page program, read array slow sf update.pp.do - write page program, read dual out sf update.pp.qo - write page program, read quad out sf update.pp.dio - write page program, read dual io sf update.pp.qio - write page program, read quad io sf update.qp.af - write quad program, read array fast sf update.qp.as - write quad program, read array slow sf update.qp.do - write quad program, read dual out sf update.qp.qo - write quad program, read quad out sf update.qp.dio - write quad program, read dual io sf update.qp.qio - write quad program, read quad io
Though it seems to be lengthy, but may useful with lot of combinations from user. My intention is to use the existing argument count with changes in the command set.
Are there cases where for the current device we're operating on that can handle more than one of these, aside from fast or slow? And do we really need to offer both fast and slow?
Yes as per as I know spansion, numonyx and winbond flashes are supporting all the operation modes that I listed above.
These are very generic w.r.t above flashes.or I can say these are commonly available modes.
And when hooked up via whichever SPI controller you have, all of those modes are also available and we can't really "guess" about using a faster mode?
I didn't get you. In general, u-boot should provide all the possible operation modes and the choice should be up to user. Please elaborate as I seem to be missing something.
Unless I'm missing something (or we're talking about different things), you have a SPI flash that do quad (or dual) read/write. But it also has to be connected to a controller that talks quad (or dual).
So is there any way we can make sf read/write/update be the fastest supported (and why do we want fast and slow quad programming?) by the controller and chip? I can see having to do "sf read.qp.qf ..." and so forth leading to some less than desired user interaction.
- -- Tom