On Fri, Sep 24, 2010 at 10:43 AM, Wolfgang Denk wd@denx.de wrote:
Dear Feng Kan,
In message AANLkTin-rbM0NDqZmZKCYp45-m9S+3H_Fb7DwzzEHkUw@mail.gmail.com you wrote:
FKAN: Dear Wolfgang, is the symmetry needed here? If a user plan to use the usb, he will trigger the function. Otherwise, on a stop what value would we put it back to.
Design rules say:
Shall initialize only such peripherals used by U-Boot itself, and must deinitialize them after use. Note that especially the deinitialization is mandatory!
FKAN: I agree, thanks. However, this conflict with one of your other rule "Don't make U-Boot slow". If another software entity wish to use the GPIO after, the code would deinit to gpio state and the other init would init gpio to the same state. Essentially doubling the code doing the same thing.
Isn't this GPI reset to the initial values part of the deinitialization sequence?
FKAN: In this case, gpio is double muxed in functionality. Do we need to remember state if the gpio is tri-muxed?
Best regards,
Wolfgang Denk
-- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de The software required `Windows 95 or better', so I installed Linux.