[En-Nut-Discussion] Next Nut/OS 5 release candidate

Uwe Bonnes bon at elektron.ikp.physik.tu-darmstadt.de
Thu Oct 11 16:25:39 CEST 2012

>>>>> "Harald" == Harald Kipp <harald.kipp at egnite.de> writes:

    Harald> Hi Uwe, On 11.10.2012 12:28, Uwe Bonnes wrote:
    >>>>>>> "Harald" == Harald Kipp <harald.kipp at egnite.de> writes:
    Harald> And the latter causes the following problem (probably on all ARM
    Harald> targets):
    >>  Could you test current svn?

    Harald> r4751 fixed this.


    >> I started a discusssion some time ago about the need for most
    >> GPIO_CFG defines common. I couldn't make my arguments
    >> understandable. Are they more understandable now?

    Harald> What thread are you referring to. This one?

    Harald> http://lists.egnite.de/pipermail/en-nut-discussion/2012-September/013942.html

No. I meant

    >> Rethinking the commit, probably in nut/include/dev/gpio.h after all
    >> includes #if !defined(GPIO_CFG_INIT_HIGH) #define GPIO_CFG_INIT_HIGH
    >> 0 #endif
    >> #if !defined(GPIO_CFG_INIT_LOW) #define GPIO_CFG_INIT_LOW 0 #endif
    >> would have been better. Should I do another commit?

    Harald> No, I'd prefer the current solution. With the one above the
    Harald> individual driver is no longer able to properly adapt to a
    Harald> missing feature, like

    Harald> int FooBarApi(void) { 
    Harald> #ifdef GPIO_CFG_INIT_HIGH /* Normal code. */ 
    Harald> ...  return 0; 
    Harald> #else /* Not supported, return an error. */
    Harald> return -1;
    Harald>  #endif
    Harald>  }

But with  nut/include/dev/gpio.h containing


#if !defined(GPIO_CFG_INIT_HIGH)

#if !defined(GPIO_CFG_INIT_LOW)
, your user code above _can_ do
==warn user==
if the requested feature is essential, but compile will _not_ break if user
code handles the feature as a welcome feature, not a must..

As with time more architectures will implement the feature, the always
needed check in your code above become more and more superfluous...

Uwe Bonnes                bon at elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------

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